September 2004
NSF04/16/EPADWCTR
EPA/600/R-04/186
Environmental Technology
Verification Report
Removal of Arsenic in Drinking Water
Watts Premier
M-Series M-15,000 Reverse
Osmosis Treatment System
Prepared by
NSF International
Under a Cooperative Agreement with
U.S. Environmental Protection Agency
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THE ENVIRONMENTAL TECHNOLOGY VERIFICATION
PROGRAM
ET
>O
v
U.S. Environmental Protection Agency NSF International
ETV Joint Verification Statement
TECHNOLOGY TYPE: MEMBRANE FILTRATION USED IN DRINKING WATER
TREATMENT SYSTEMS
APPLICATION: REMOVAL OF ARSENIC
TECHNOLOGY NAME: WATTS PREMIER M-SERIES M-15,000 REVERSE
OSMOSIS (RO) TREATMENT SYSTEM
COMPANY: WATTS PREMIER
ADDRESS: 1725 W. WILLIAMS DRIVE, #C-20 PHONE: (623)505-1514
PHOENIX, ARIZONA 85027 FAX: (623)931-0191
WEB SITE: www.wattspremier.com
EMAIL: murphysp@wattsind.com
The U.S. Environmental Protection Agency (EPA) supports the Environmental Technology Verification
(ETV) Program to facilitate the deployment of innovative or improved environmental technologies
through performance verification and dissemination of information. The goal of the ETV Program is to
further environmental protection by accelerating the acceptance and use of improved and more cost-
effective technologies. ETV seeks to achieve this goal by providing high-quality, peer-reviewed data on
technology performance to those involved in the design, distribution, permitting, purchase, and use of
environmental technologies.
ETV works in partnership with recognized standards and testing organizations, stakeholder groups
(consisting of buyers, vendor organizations, and permitters), and with the full participation of individual
technology developers. The program evaluates the performance of innovative technologies by developing
test plans that are responsive to the needs of stakeholders, conducting field or laboratory tests (as
appropriate), collecting and analyzing data, and preparing peer-reviewed reports. All evaluations are
conducted in accordance with rigorous quality assurance protocols to ensure that data of known and
adequate quality are generated and that the results are defensible.
NSF International (NSF) in cooperation with the EPA operates the Drinking Water Systems (DWS)
Center, one of seven technology areas under the ETV Program. The DWS Center recently evaluated the
performance of a membrane separations system for the reduction of arsenic in drinking water. This
verification statement provides a summary of the test results for the Watts Premier MSeries Ml5,000
Reverse Osmosis (RO) Treatment System. MWH, an NSF-qualified field testing organization (FTO),
performed the verification testing. The verification report contains a comprehensive description of the
test.
04/16/EPADWCTR The accompanying notice is an integral part of this verification statement. September 2004
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ABSTRACT
Verification testing of the Watts Premier M-Series M-15,000 RO Treatment System was conducted over a
31-day period from April 26, 2004, through May 26, 2004. This test was conducted at the Coachella
Valley Water District (CVWD) Well 7802 in Thermal, California. The source water was a chlorinated
groundwater supply. Based on the manufacturer's recommendations, the unit was operated at an average
inlet pressure of 135 pounds per square inch (psi), water recovery of 53%, flux of 34 gallons per square-
foot per day (gfd), and a specific flux of approximately 0.36 gfd/psi at 25 degrees Celsius (°C). The total
arsenic (As) concentration in the feed water averaged 14 micrograms per liter (ug/L) during the testing
period. The M-15,000 RO Treatment System reduced the arsenic levels to below detection (1.0 ug/L) for
all but the last two samples, which were 1.4 and 1.2 ug/L. Six sets of samples were speciated and the
dominant form of arsenic was As(V).
The system operated for 27 days of the 31-day verification period, with three system shut downs due to
operational issues associated with the pre-filter. The verification study indicated that arsenic can be
removed by the M-15,000 RO Treatment System, but depending on the source water characteristics, the
appropriate pre-filter selection is important to prevent clogging of the pre-filters.
TECHNOLOGY DESCRIPTION
The following technology description was provided by the manufacturer and has not been verified.
The M-15,000 RO Treatment System contains six pressure vessels, each containing one 4" x 40"
membrane module. Each stainless steel pressure vessel is four inches (10 cm) in diameter and
approximately 45 inches (110 cm) long. The M-15,000 RO Treatment System is a skid-mounted unit that
is constructed with a carbon steel frame and powder coating. The verification unit is 37 %" (length) x 28
%" (depth) x 53 1A>" (height) and requires a minimum of 18" clearance on all sides for servicing, 40"
clearance on top, and a floor sink drain of 1 1A" diameter within 10' of the processing unit. The main
components of the RO unit are a 3 Hp feed pump, carbon bloc (for removal of chlorine) or sediment pre-
filter pretreatment, six pressure vessels, and an in-line conductivity meter. The M-15,000 RO Treatment
System unit may use either a carbon pretreatment for removal of chlorine or a sediment pre-filter as
standard equipment for the system. The membranes are not tolerant of chlorine and, therefore, when the
system is used on a chlorinated water source, the carbon pretreatment should be used.
VERIFICATION TESTING DESCRIPTION
Test Site
The verification testing site was the CVWD Well 7802 located in Thermal, California. The feed water for
the verification study was a chlorinated source, with an average free chlorine residual of 0.47 milligrams
per liter (mg/L). The chlorine enters the distribution system at the discharge manifold, and was fed from
a Hammond's tablet feeder using calcium hypochlorite tablets as the chlorine source. The average feed
water quality during the verification testing is provided in the table below.
In addition to being a suitable fit for water quality, the site also had sufficient access (1 acre site); full
electrical supply with backup diesel powered generator; 6' privacy/security wall; all utilities readily
available including raw water supply, power, and a drain (blow-off structure) for the discharge of the
water from the ETV verification testing; and safety facilities, including an emergency shower and
eyewash.
04/16/EPADWCTR The accompanying notice is an integral part of this verification statement. September 2004
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Total Arsenic
Dissolved Arsenic
As (III)
As(V)1
TOC
Calcium
Chloride
Hardness
Alkalinity
Free Chlorine
Total Chlorine
pH2
Temperature
Mg/L
Mg/L
Mg/L
Mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
--
°C
27
5
5
5
5
5
5
5
5
18
18
27
54
14
14
3.7
11
<0.50
4.8
8.5
18
83
0.47
0.51
9.213
27.5
Turbidity
Conductivity
TDS
TSS
Manganese
Iron
Barium
Silica
Fluoride
Sulfate
Chromium
Vanadium
NTU3
umoh/cm
mg/L
mg/L
Mg/L
mg/L
Mg/L
mg/L
mg/L
mg/L
Mg/L
Mg/L
5
54
27
5
5
5
5
5
5
5
5
5
0.40
231
140
<10
<2.0
0.019
7.1
15
0.80
20
13
49
Average Feed Water Quality during Verification Testing
#of
Parameter Units Samples Average Parameter
Units
#of
Samples
Average
1 As (V) is a calculated value.
3 pH is reported as the median, not the average.
3 Nephelometric Turbidity Unit(s).
Methods and Procedures
Water quality was monitored from three water streams: feed water, permeate, and concentrate.
Conductivity, pH, turbidity, chlorine (free and total), temperature, alkalinity, hardness analyses were
conducted on-site, using equipment set up in the pump house at CVWD Well 7802 and in accordance
with Standard Methods for the Examination of Water and Wastewater, 2Cfh edition. Conductivity and
feed water temperature were monitored twice per day, while pH was monitored once per day. Alkalinity,
hardness, chlorine, and turbidity were monitored once per week on-site using methods approved by NSF.
The following additional samples were sent to MWH Laboratories for analysis: arsenic (total, dissolved,
and As+3), total suspended solids (TSS), total dissolved solids (TDS), total organic carbon (TOC), silica,
barium, calcium, chloride, sulfate, iron, manganese, fluoride, chromium, and vanadium. Total arsenic
and TDS samples were collected once per day; dissolved arsenic, As+3, TSS, TDS, TOC, silica, barium,
calcium, chloride, sulfate, iron, manganese, fluoride, chromium, and vanadium samples were collected
once per week. One sample was collected during the verification test for silt density index (SDI) analysis.
Complete descriptions of the verification testing results and quality assurance/quality control procedures
are included in the verification report.
VERIFICATION OF PERFORMANCE
System Operation
RO is a pressure-driven process, with the pressure used for separation by allowing fresh water to move
through a membrane, leaving various dissolved constituents of the water behind. In the M-l5,000 RO
Treatment System, feed water is initially passed through a pre-filter (sediment filter or carbon bloc for
chlorine removal) to remove particles that have the potential to damage the membrane. There is a
sampling port just prior to the pre-filter to collect the feed water samples. After passing through the pre-
filter, the feed water is blended with re-circulated concentrate water and is then referred to as the inlet
water. The inlet water is then sent through a booster pump and after leaving the discharge side of the
pump, the water line is split and feeds the two separate banks of membranes (six membranes in total),
starting with membrane 1 and 4. For the first bank of membranes, concentrate from membrane 1 feeds
membrane 2 and concentrate from membrane 2 feeds membrane 3. For the second bank of membranes,
concentrate from membrane 4 feeds membrane 5 and concentrate from membrane 5 feeds membrane 6.
04/16/EPADWCTR
The accompanying notice is an integral part of this verification statement.
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September 2004
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Permeate from all membranes is collected from the bottom of the housing and exits the unit as drinking
water. There is a permeate sample port for each of the six membranes, as well as the blended permeate
from all six of the membranes. During the verification test, permeate samples were collected from the
blended permeate sample port. Concentrate from membranes 3 and 6 is split, some being purged to waste
and some re-circulating back to the head of the system, just after the pre-filter where it is blended with the
feed water to create the inlet water. The concentrate that is re-circulated back to the head of the system is
referred to as recycle water.
The M-15,000 RO Treatment System was set up in accordance with the manufacturer's recommendations
the week prior to the verification test. The unit was tested to make sure all systems were operating in
accordance with their recommended ranges. Based on discussions between the FTO and the
manufacturer, the set points were adjusted to achieve a 50% permeate recovery. Once the set points were
adjusted, the system flow rates were stable for the remainder of the verification period. The feed water
pressure was stable throughout the testing period, however, the inlet pressure varied from 102 to 145 psi,
due to clogging of the carbon bloc pre-filter. Once the pre-filter was replaced with a sediment filter, the
inlet pressures stabilized (140 to 150 psi) for the remainder of the verification testing.
Water Quality Results
The M-15,000 RO Treatment System removed the feed water total arsenic from 14 ug/L (on average) to
non-detectable levels (<1.0 ug/L) for all but the last two samples collected, which were 1.4 and 1.2 ug/L.
As shown in the figure below, the unit was able to produce a consistent, high quality permeate with total
arsenic levels below 1.0 ug/L in 95% of the samples over the range of feed water of 12 to 16 ug/L.
Throughout most of the verification test, the total arsenic mass balance was very close, with the exception
of April 29, 2004, and May 10, 2004, where the arsenic concentration in the concentrate stream was
significantly higher (greater than the 95% confidence interval), at 84 ug/L and 38 ug/L respectively. The
permeate conductivity and TDS slowly increased throughout the verification testing, starting around 6.4
umoh/cm and increasing to 76.6 umoh/cm for conductivity and starting at <10 mg/L and increasing to 45
mg/L for TDS. During the verification testing, a total of five weekly samples were collected for inorganic
analyses. Based on these five samples, the M-15,000 RO Treatment System removed on average: >72%
barium, >79% calcium, 85% fluoride, 85% chloride, >92% chromium, >90% sulfate, >93% vanadium,
38% iron, and 62% silica. Manganese was also sampled and analyzed during the verification testing, but
the percent removal could not be determined due to non-detectable (<2 ug/L) levels for all of the feed
water and permeate samples.
04/16/EPADWCTR The accompanying notice is an integral part of this verification statement. September 2004
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-n Concentrate
Feed Water
-O Permeate
Verificatin Testing Date
Temporal Plot of Total Arsenic
Operation and Maintenance Results
The system ran continuously for 27 of the 31-day verification testing period. For one 4-day period, the
system was shut down due to operational issues. Clogging of the carbon bloc pre-filter is believed to be
the cause of the shut down. The unit automatically shut down on two separate occasions, also believed to
be related to clogging of the carbon bloc pre-filter. On May 13, 2004 the carbon bloc pre-filter was
replaced with a 20-micron sediment pre-filter. The system ran continuously after the sediment filter was
installed, until the end of the verification testing on May 26, 2004, when the system was manually shut
down.
Quarterly maintenance was conducted upon completion of the verification testing. The maintenance
procedure took approximately 45 minutes to change out the O-rings on the pre-filter and brine line, and
replace the pre-filter and two of the six RO membranes. Upon completion of the maintenance procedures,
the system was started back up and both water quality and operational conditions were recorded. The
specific flux immediately prior to the maintenance was 0.34 gfd/psi and upon start up after the
maintenance was 0.33 gfd/psi, thus a 97% recovery of specific flux was achieved upon completion of the
maintenance procedures.
04/16/EPADWCTR
The accompanying notice is an integral part of this verification statement.
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September 2004
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Consumables and Waste Generation
There were no "consumable" chemical items used for the verification testing; however, the pre-filter to
the system would be a consumable product and would have to be disposed of as solid waste. The
concentrate waste stream produced from the verification test was blended back with the permeate water
for an equivalent water quality to the feed water from the CVWD Well 7802. This water was then sent to
a blow-off structure for disposal. The estimated concentrate production rate was 17,300 gallons per day,
based on the targeted 50% permeate recovery.
Quality Assurance/Quality Control
NSF provided technical and quality assurance oversight of the verification testing as described in the
verification report, including an audit of nearly 100% of the data. NSF personnel also conducted a
technical systems audit during testing to ensure the testing was in compliance with the test plan. A
complete description of the QA/QC procedures is provided in the verification report.
Original Signed by
Lawrence W. Reiter
09/30/04
Original Signed by
Gordon Bellen
09/30/04
Lawrence W. Reiter Date
Acting Director
National Risk Management Research Laboratory
Office of Research and Development
United States Environmental Protection Agency
Gordon Bellen
Vice President
Research
NSF International
Date
NOTICE: Verifications are based on an evaluation of technology performance under specific,
predetermined criteria and the appropriate quality assurance procedures. EPA and NSF make no
expressed or implied warranties as to the performance of the technology and do not certify that a
technology will always operate as verified. The end-user is solely responsible for complying with
any and all applicable federal, state, and local requirements. Mention of corporate names, trade
names, or commercial products does not constitute endorsement or recommendation for use of
specific products. This report is not an NSF Certification of the specific product mentioned
herein.
Availability of Supporting Documents
Copies of the ETV Protocol for Equipment Verification Testing for Arsenic Removal
dated September 2003, the ETV Protocol for Equipment Verification Testing for Removal
of Inorganic Constituents dated April 2002, the verification statement, and the
verification report (NSF Report # 04/16/EPADWCTR) are available from the following
sources:
(NOTE: Appendices are not included in the verification report. Appendices are available
from NSF upon request.)
1. ETV Drinking Water Systems Center Manager (order hard copy)
NSF International
P.O. Box 130140
Ann Arbor, Michigan 48113-0140
2. NSF web site: http://www.nsf. org/etv (electronic copy)
3. EPA web site: http://www. epa.gov/etv (electronic copy)
04/16/EPADWCTR
The accompanying notice is an integral part of this verification statement. September 2004
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September 2004
Environmental Technology Verification Report
Removal of Arsenic in Drinking Water
Watts Premier M-Series
M-15,000 Reverse Osmosis Treatment System
Prepared for:
NSF International
Ann Arbor, Michigan 48105
Prepared by:
MWH
Pasadena, CA 91101
Under a cooperative agreement with the U.S. Environmental Protection Agency
Jeffrey Q. Adams, Project Officer
National Risk Management Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
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Notice
The U.S. Environmental Protection Agency (EPA), through its Office of Research and
Development, has financially supported and collaborated with NSF International (NSF) under
Cooperative Agreement No. R-82833301. This verification effort was supported by the Drinking
Water Systems (DWS) Center, operating under the Environmental Technology Verification
(ETV) Program. This document has been peer reviewed, reviewed by NSF and EPA, and
recommended for public release.
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Foreword
The U.S. Environmental Protection Agency (EPA) is charged by Congress with
protecting the Nation's land, air, and water resources. Under a mandate of national
environmental laws, the Agency strives to formulate and implement actions leading to a
compatible balance between human activities and the ability of natural systems to support and
nurture life. To meet this mandate, EPA's research program is providing data and technical
support for solving environmental problems today and building a science knowledge base
necessary to manage our ecological resources wisely, understand how pollutants affect our
health, and prevent or reduce environmental risks in the future.
The National Risk Management Research Laboratory (NRMRL) is the Agency's center
for investigation of technological and management approaches for preventing and reducing risks
from pollution that threaten human health and the environment. The focus of the Laboratory's
research program is on methods and their cost-effectiveness for prevention and control of
pollution to air, land, water, and subsurface resources; protection of water quality in public water
systems; remediation of contaminated sites, sediments and ground water; prevention and control
of indoor air pollution; and restoration of ecosystems. NRMRL collaborates with both public
and private sector partners to foster technologies that reduce the cost of compliance and to
anticipate emerging problems. NRMRL's research provides solutions to environmental problems
by: developing and promoting technologies that protect and improve the environment; advancing
scientific and engineering information to support regulatory and policy decisions; and providing
the technical support and information transfer to ensure implementation of environmental
regulations and strategies at the national, state, and community levels.
This publication has been produced as part of the Laboratory's strategic long-term
research plan. It is published and made available by EPA's Office of Research and Development
to assist the user community and to link researchers with their clients.
Lawrence W. Reiter, Acting Director
National Risk Management Research Laboratory
in
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Table of Contents
Section Page
Verification Statement VS-i
Title Page i
Notice ii
Foreword iii
Table of Contents iv
Abbreviations and Acronyms ix
Acknowledgements x
Chapter 1 Introduction 1
1.1 ETV Purpose and Program Operation 1
1.2 Testing Participants and Responsibilities 1
1.2.1 NSF International 2
1.2.2 Field Testing Organization 2
1.2.3 Manufacturer 3
1.2.4 Analytical Laboratory 3
1.2.5 U.S. Environmental Protection Agency 4
1.3 Verification Testing Site 4
1.3.1 Source Water 4
1.3.2 Pilot Effluent Discharge 5
1.3.3 Discharge Permits 5
Chapter 2 Equipment Description and Operating Processes 6
2.1 Equipment Description 6
2.2 Operating Process 10
Chapter 3 Methods and Procedures 13
3.1 Quantitative and Qualitative Evaluation Criteria 13
3.2 Key Treated Water Quality Parameters 13
3.2.1 Key Groundwater Quality Parameters the Equipment is Designed to Address 13
3.2.2 Key Treated Water Quality Parameters for Evaluating Equipment Performance ...14
3.3 Calculations 14
3.3.1 Calculation of Statistical Uncertainty 14
3.3.2 Calculation and Definition of Operational Parameters 15
3.4 Testing Schedule 19
3.5 Operation and Maintenance 20
3.6 Field Operations Procedures 20
3.7 Environmental Technology Verification Testing Plan 20
3.7.1 Task 1: Membrane Operation 21
3.7.2 Task 2: Cleaning Efficiency 21
3.7.3 Task 3: Feed Water and Treated Water Quality Monitoring 21
3.7.4 Task 4: Data Handling Protocol 22
3.7.5 Task 5: Quality Assurance Project Plan (QAPP) 22
3.8 Task 1: Membrane Optimization 22
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Table of Contents (continued)
Section Page
3.8.1 Experimental Objectives 23
3.8.2 Work Plan 23
3.8.3 Analytical Schedule 24
3.8.4 Evaluation Criteria and Minimum Reporting Criteria 24
3.9 Task 2: Cleaning Efficiency 25
3.9.1 Experimental Objectives 25
3.9.2 Work Plan 25
3.9.3 Analytical Schedule 26
3.9.4 Evaluation Criteria and Minimum Reporting Criteria 26
3.10 Task 3: Water Quality Monitoring 27
3.10.1 Experimental Objectives 27
3.10.2 Work Plan 28
3.10.3 Analytical Schedule 28
3.10.4 Evaluation Criteria And Minimum Reporting Criteria 29
3.11 Task 4: Data Handling Protocol 29
3.11.1 Experimental Objectives 30
3.11.2 Work Plan 30
3.12 Task 5: Quality Assurance Project Plan (QAPP) 31
3.12.1 Experimental Objectives 31
3.12.2 Work Plan 31
3.12.3 Monthly QA/QC Verification 31
3.12.4 Data Correctness 31
3.12.4.1 Representativeness 32
3.12.4.2 Statistical Uncertainty 36
3.12.4.3 Methodology for Measurement of Precision and Accuracy 37
3.12.4.4 Completeness 41
3.12.5 Calculation of Indictors of Data Quality 41
3.12.6 Corrective Action Plan 42
3.13 Operation And Maintenance 43
3.13.1 Operation 43
3.13.2 Maintenance 44
3.13.3 Operability 45
Chapter 4 Results and Discussion 46
4.1 Introduction 46
4.2 Task 1: Membrane Operation 46
4.2.1 General Operational Performance 41
4.2.1.1 Feed Water, Permeate, Concentrate, and Recycle Flow Rates 47
4.2.1.2 Membrane Element Inlet and Feed Water Pressures 50
4.2.1.3 Water Recovery and Recycle Ratio 53
4.2.1.4 Feed Water Temperature 55
4.2.1.5 Flux, Specific Flux, Net Driving Pressure, and Osmotic Pressure 56
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Table of Contents (continued)
Section Page
4.2.2 Power Consumption 62
4.2.3 Consumables and Waste Generation 63
4.3 Task 2: Cleaning Efficiency 63
4.3.1 Measurement of Membrane Performance - Post Quarterly O&M Procedures 65
4.3.2 Review of Watts Premier Operation and Maintenance Manual 67
4.4 Task 3: Feed Water And Treated Water Quality Monitoring 67
4.4.1 Percent Removal Of Inorganic Chemical Constituents 75
4.4.2 Percent Removal Of Organic Constituents 80
4.4.2.1 Mass Balance for Total Arsenic 81
4.4.2.2 Limiting Salt Concentrations 82
4.4.3 Removal of TSS 83
4.4.4 SDI 84
4.4.5 LSI 84
4.5 Task 4: Data Handling Protocol 83
4.6 Task 5: Quality Assurance/Quality Control Results 83
4.6.1 Precision 83
4.6.2 Accuracy 88
4.6.3 Off-Site Analysis of Samples 90
4.6.3.1 Inorganic Samples 95
4.6.3.2 Organic Samples 95
4.6.4 Completeness 90
4.6.5 NSF Field Inspection 90
Chapter 5 References 97
Chapter 6 Vendor Comments 98
Table
Table 1-1: Average Feed Water Quality during Verification Testing 4
Table 2-1: Membrane Plant Design Criteria Reporting Items 9
Table 2-2: Membrane Element Characteristics 9
Table 2-3: Watts Premier M-l 5,000 RO Treatment System Specifications 11
Table 3-1: Quantitative and Qualitative Evaluation Criteria 13
Table 3-2: Operating Range of Watts Premier RO Membrane 14
Table 3-3: Key Treated Water Quality Parameters 14
Table 3-4: Equipment Operational Characteristics to be Evaluated in Each Task 22
Table 3-5: Frequency and Type of Operating Data 24
Table 3-6: Sampling Schedule and Methods for Feed, Permeate, & Concentrate Water 27
Table 3-7: Methodology for Measurement of Precision and Accuracy 37
Table 3-8: Laboratory Water Quality Indicators 39
Table 3-9: On-Site Water Quality Analysis Indicators 40
Table 3-10: Methodology for Use of Method Blanks 40
Table 3-11: Completeness Objectives Based on Sample Frequency 41
VI
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Table of Contents (continued)
Table
Page
Table 3-12: Corrective Action Plan [[[ 43
Table 4-1: Feed Water, Permeate, Concentrate and Recycle Flow Rates ..................................... 49
Table 4-2: Feed Water, Inlet, Back Pressure, and Tank Pressures ............................................... 52
Table 4-3: Water Recovery and Recycle Ratio [[[ 54
Table 4-4: Feed Water Temperature [[[ 55
Table 4-5: Daily Flux Data [[[ 57
Table 4-6: Daily Specific Flux Data at 25°C [[[ 58
Table 4-7: Osmotic Pressure Gradient [[[ 60
Table 4-8: Net Driving Pressure [[[ 62
Table 4-9: Power Totalizer for M-l 5,000 RO Treatment System ................................................ 63
Table 4-10: Pre-and Post-Maintenance Specific Flux Recoveries ............................................... 66
Table 4-11: Maintenance Efficiency Indicators [[[ 66
Table 4-12: Pre and Post O&M Feed Water, Permeate, and Concentrate Water Quality ............ 67
Table 4-13: Daily Feed Water, Concentrate, Permeate, and Total Arsenic Data ......................... 69
Table 4-14: Daily Feed Water, Concentrate, Permeate, and TDS ................................................ 71
Table 4- 15 Daily pH Analysis [[[ 72
Table 4-16: Daily Conductivity Analysis [[[ 73
Table 4-17: On-site Weekly Water Quality Monitoring [[[ 74
Table 4-18: On-site Free and Total Chlorine Monitoring [[[ 75
Table 4-19: Weekly Speciated Arsenic Analyses [[[ 76
Table 4-20: Weekly Analytical Parameters and Percent Removal ............................................... 77
Table 4-21: Percent Removal of Organic Constituents [[[ 80
Table 4-22: Daily Total Arsenic Mass Balance [[[ 82
Table 4-23: Solubility Products of Limiting Salt Concentrations ................................................ 83
Table 4-24: Removal of Total Suspended Solids [[[ 84
Table4-25: LSI Calculations (April 26, 2004) [[[ 85
Table 4-26: Weekly Off-site Analytical Precision [[[ 87
Table 4-27: On-site Analytical Precision [[[ 88
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Table of Contents (continued)
Figure Page
Figure 4-4: Temporal plot of flux verses time 56
Figure 4-5: Specific flux at 25°C verses time 58
Figure 4-6: Osmotic pressure gradient verses time 59
Figure 4-7: Temporal profile of net driving pressure 61
Figure 4-8: Temporal plot of total arsenic 68
Figure 4-9: Temporal plot of TDS 70
Figure 4-10: Temporal plot of silica 78
Figure 4-11: Temporal plot of fluoride 78
Figure 4-12: Temporal plot of iron 79
Figure 4-13: Temporal plot of chloride 79
Figure 4-14: Temporal plot of sulfate 80
Figure 4-15: Daily total arsenic mass balance 81
Photograph Page
Photograph 1: Permeate and Concentrate Discharge Lines 5
Photograph 2: Watts Premier M-15,000 RO Treatment System at CVWD Well 7802 8
Photograph 3: Pre-Filter to Watts Premier M-15,000 RO Treatment System 10
Photograph 4: Watts Premier M-15,000 RO Treatment System Pre-filters 64
Photograph 5: Membrane RO Number 6 - Post Verification Testing 65
Appendices
Appendix A: Watts Premier M-Series M-15,000 RO Treatment System O&M Manual
Appendix B: On-Site Arsenic Speciation Procedures
Appendix C: On-Site Logbook
Appendix D: Analytical Data from MWH Laboratories
Appendix E: Analytical Data and Procedures from SDI Analysis
Vlll
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Abbreviations and Acronyms
AM morning
As arsenic
As (III) arsenite
As (V) arsenate
ASTM American Society of Testing and Materials
°C degree Celsius
CVWD Coachella Valley Water District
°F degree Fahrenheit
EPA Environmental Protection Agency
ETV environmental technology verification
Ft feet
FTO field testing organization
gfd gallons per square-foot per day
gfd/psi gallons per square-foot per day per pounds per square inch
gpd gallons per day
gpm gallon per minute
LCS laboratory control sample
LFM laboratory fortified matrix
LSI Langelier Saturation Index
MB method blank
mL milliliter
mg/L milligram
MRL minimum reporting limit
NDP net driving pressure
NELAC National Environmental Laboratory Accreditation Conference
NIST National Institute of Standards and Technology
NRMRL National Risk Management Research Laboratory
NSF NSF International (formerly known as the National Sanitation Foundation)
NTU nephelometric turbidity unit(s)
O&M operation and maintenance
p pressure
PM evening
psi pounds per square inch
psig gauge pressure
PSTP Product Specific Test Plan
Q flow rate
QAPP Quality Assurance Project Plan
RO reverse osmosis
RPD Relative percent difference
SDI silt density index
T temperature
TDS total dissolved solids
TOC total organic carbon
TSS total suspended solids
ug microgram
IX
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Acknowledgments
The field testing organization (FTO), MWH, was responsible for all elements in the testing
sequence, including collection of samples, calibration and verification of instruments, data
collection and analysis, data management, data interpretation, and the preparation of this report.
MWH
300 N. Lake Ave, Suite 1200
Pasadena, California 91101
Contact Person: Thomas Gillogly, Ph.D.
The laboratory selected for analytical work for this study was:
MWH Laboratories
750 Royal Oaks Lane, Suite 100
Monrovia, California 91016
Contact Person: Andrew Eaton, Ph.D.
The manufacturer of the equipment was:
Watts Premier
1725 W. Williams Drive, #C-20
Phoenix, Arizona 85027
Contact Person: Shannon Murphy
MWH wishes to thank NSF International (NSF), especially Mr. Bruce Bartley, Project Manager,
and Mrs. Angela Beach, Project Coordinator, for providing guidance and program management.
MWH also wishes to thank the Coachella Valley Water District (CVWD) for providing the site
for verification testing including providing assistance in connecting to the water system and all
necessary utilities (water, sewer, and electrical).
NSF wishes to thank Mr. Dale Scherger, Environmental Consultant, Scherger Associates, for
providing technical guidance.
Mr. Shannon Murphy and Mr. Adam Nelson, Watts Premier, are to be commended for providing
the treatment system and the excellent technical and product expertise.
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Chapter 1
Introduction
1.1 ETV Purpose And Program Operation
The U.S. Environmental Protection Agency (EPA) has created the Environmental Technology
Verification (ETV) Program to facilitate the deployment of innovative or improved
environmental technologies through performance verification and dissemination of information.
The goal of the ETV Program is to further environmental protection by accelerating the
acceptance and use of improved and more cost-effective technologies. ETV seeks to achieve this
goal by providing high-quality, peer-reviewed data on technology performance to those involved
in the design, distribution, permitting, purchase, and use of environmental technologies.
ETV works in partnership with recognized standards and testing organizations; with stakeholder
groups consisting of buyers, vendor organizations, and permitters; and with the full participation
of individual technology developers. The program evaluates the performance of innovative
technologies by developing test plans responsive to the needs of stakeholders, conducting field
demonstrations, collecting and analyzing data, and preparing peer-reviewed reports. All
evaluations are conducted in accordance with rigorous quality assurance protocols to ensure that
data of known and adequate quality are generated and that the results are defensible.
The EPA has partnered with NSF International (NSF) under the ETV Drinking Water Systems
(DWS) Center to verify the performance of small drinking water systems that serve small
communities. A goal of verification testing is to enhance and facilitate the acceptance of small
drinking water treatment equipment by state drinking water regulatory officials and consulting
engineers, while reducing the need for testing of equipment at each location where the
equipment's use is contemplated. NSF meets this goal by working with manufacturers and NSF-
qualified Field Testing Organizations (FTOs) to conduct verification testing under the approved
protocols. It is important to note that verification of the equipment does not mean the equipment
is "certified" by NSF or "accepted" by EPA. Rather, it recognizes that the performance of the
equipment has been determined and verified by these organizations for those conditions tested by
the FTO.
The ETV DWS Center evaluated the performance of the Watts Premier M-Series M-15,000
Reverse Osmosis (RO) Treatment System, which is a membrane technology used in drinking
water treatment system applications. The verification test evaluated the ability of the RO system
to remove arsenic from drinking water under specific feed water quality and conditions. This
document provides the verification test results for the M-15,000 RO Treatment System.
1.2 Testing Participants And Responsibilities
The ETV testing of the M-15,000 RO Treatment System was a cooperative effort among the
following participants:
NSF International
MWH
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Watts Premier
MWH Laboratories
U.S. Environmental Protection Agency
The following is a brief description of all of the ETV participants and their roles and
responsibilities.
1.2.1 NSF International
NSF is an independent, not-for-profit testing and certification organization dedicated to public
health and safety and to the protection of the environment. Founded in 1946 and located in Ann
Arbor, Michigan, NSF has been instrumental in the development of consensus standards for the
protection of public health and the environment. NSF also provides testing and certification
services to ensure products bearing the NSF Name, Logo and/or Mark meet those standards. The
EPA partnered with NSF to verify the performance of drinking water treatment systems through
the EPA's ETV Program.
NSF provided technical oversight of the verification testing and conducted an audit of the field
analytical data gathering and recording procedures. NSF also provided review of the Product
Specific Test Plan (PSTP) as well as this report.
Contact Information:
NSF International
789 N. Dixboro Road
Ann Arbor, MI 48105
Phone: (734) 769-8010
Fax: (734)769-0109
Contact: Bruce Bartley, Project Manager
Email: bartley@nsf.org
1.2.2 Field Testing Organization
MWH, an environmental engineering consulting firm, conducted the verification testing of the
M-15,000 RO Treatment System. MWH is an NSF-qualified FTO for the ETV DWS Center.
The FTO was responsible for conducting the verification testing for 31 calendar days. The FTO
provided all needed logistical support, established a communications network, and scheduled and
coordinated activities of all participants. The FTO was responsible for ensuring the testing
location and feed water conditions were such that the verification testing could meet its stated
objectives. The FTO prepared the PSTP; oversaw the pilot testing; managed, evaluated,
interpreted, and reported on the data generated by the testing; and evaluated and reported on the
performance of the technology.
FTO employees conducted the on-site analyses and data recording during the testing. The FTO's
project engineer and project manager provided oversight of the daily tests.
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Contact Information:
MWH
300 N. Lake Avenue, Suite 1200
Pasadena, CA 91101
Phone: (626) 568-6010
Fax: (626) 568-6015
Contact Person: Thomas Gillogly, Ph.D
Email: Thomas.Gillogly@MWHGlobal.com
1.2.3 Manufacturer
The treatment system is manufactured by Watts Premier, a water treatment equipment
manufacturer and supplier. The manufacturer was responsible for supplying a field-ready M-
15,000 RO Treatment System equipped with all necessary components, including treatment
equipment, instrumentation and controls and an operation and maintenance (O&M) manual. The
manufacturer was responsible for providing logistical and technical support, as needed, as well
as technical assistance to the FTO during operation and monitoring of the equipment undergoing
field verification testing.
Contact Information:
Watts Premier
1725 W. Williams Drive, #C-20
Phoenix, Arizona 85027
Phone: (623)505-1514
Fax: (623)931-0191
Contact Person: Shannon Murphy
Email: murphysp@wattsind.com
1.2.4 A nalytical Laboratory
The specific responsibilities of the water quality analytical staff, MWH Laboratory, were to
provide all off-site water quality analyses prescribed in the PSTP according to the Quality
Assurance/Quality Control (QA/QC) and the protocols contained therein, provide reports with
the analytical results to the data manager, and provide detailed information on the analytical
procedures implemented.
Contact Information:
MWH Laboratories
750 Royal Oaks, Suite 100
Monrovia, CA 91016
Phone: (626)386-1100
Fax: (626)386-1101
Contact Person: Andrew Eaton, Ph.D.
Email: Andrew.Eaton@MWHGlobal.com
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1.2.5 U.S. Environmental Protection Agency
The EPA, through its Office of Research and Development, has financially supported and
collaborated with NSF under Cooperative Agreement No. R-82833301. This verification effort
was supported by the DWS Center operating under the ETV Program. This document has been
peer reviewed, reviewed by NSF and EPA, and recommended for public release.
1.3 Verification Testing Site
The test site selected for the verification testing of the M-15,000 RO Treatment System was the
Coachella Valley Water District's (CVWD) Well 7802 located in Thermal, California. The
following sections provide additional information on the test site (source water characteristics
and discharge method).
1.3.1 Source Water
The feed water used during the verification study was a chlorinated source, with an average free
chlorine residual of 0.47 milligrams per liter (mg/L). The chlorine enters the distribution system
at the discharge manifold, and was fed from a Hammond's tablet feeder using calcium
hypochlorite tablets as the chlorine source. A summary of the average feed water quality values
from the 27 days of operation during the verification testing is presented in Table 1-1. Complete
descriptions of the verification testing results and quality assurance/quality control procedures
are included in Chapters 3 and 4.
Table 1-1: Average Feed Water Quality during Verification Testing
Parameter
Total Arsenic
Dissolved Arsenic
Arsenite (As (III))
Arsenate (As(V))1
Total Organic
Carbon (TOC)
Calcium
Chloride
Hardness
Alkalinity
Free Chlorine
Total Chlorine
pH2
Temperature
Number of
Units Samples
Mg/L
Mg/L
Mg/L
Mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
--
°C
27
5
5
5
5
5
5
5
5
18
18
27
54
Average
14
14
3.7
11
<0.50
4.8
8.5
18
83
0.47
0.51
9.21
27.5
Parameter
Turbidity
Conductivity
Total Dissolved
Solids (TDS)
Total Suspended
Solids (TSS)
Manganese
Iron
Barium
Silica
Fluoride
Sulfate
Chromium
Vanadium
Number of
Units Samples
NTU3
umoh/cm
mg/L
mg/L
Mg/L
mg/L
Mg/L
mg/L
mg/L
mg/L
Mg/L
Mg/L
5
24
27
5
5
5
5
5
5
5
5
5
Average
0.40
231
140
<10
<2.0
0.019
7.1
15
0.80
20
13
49
As (V) is a calculated value.
pH is reported as the median, not the average.
Nephelometric Turbidity Unit(s).
-------
1.3.2 Pilot Effluent Discharge
All treated water (RO permeate) and waste (RO concentrate) were blended back together and
sent to a blow-off drain for disposal, see clear 1-inch flexible tubing in Photograph 1. The
blended water produced from the equipment being tested was not anticipated to adversely impact
the environment, as the quality of the blended water was equivalent to the well's raw water
quality, with the exception of chlorine. The blow-off drain had sufficient capacity to accept the
blended water (treated and concentrate) flow rate for the duration of the study. De-chlorination
tablets were added to the drain where the water from the verification unit was discharging.
Permeate and concentrate
discharge lines
Photograph 1: Permeate and Concentrate Discharge Lines
1.3.3 Discharge Permits
No discharge permits were necessary for this verification study.
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Chapter 2
Equipment Description and Operating Processes
2.1 Equipment Description
The equipment tested in the ETV was the M-15,000 RO Treatment System. The M-15,000 RO
Treatment System verification unit contains six pressure vessels, each containing one 4" x 40"
membrane module. Each stainless steel pressure vessel is 4 inches (10 cm) in diameter and
approximately 45 inches (110 cm) long. A schematic of the system is shown in Figure 2-1 and a
photograph of the unit is shown in Photograph 2, which specifically shows the panel mounted
flow meters, pressure gauges, recirculation needle valve, and individual membrane sample ports.
531/2
-283/4-
fl5P
n
V230VAC/15A
,,-Water Supply Utility Connection (cold = 1" NPT)
/ ,-Permeate Connection (1" NPT)
/
oncentrate / Drain (1.25" NPT minimum)
Figure 2-1: Watts Premier M-Series M-15,000 RO Treatment System.
The feed water is initially passed through a pre-filter (sediment filter or carbon bloc for chlorine
removal) to remove particles that have the potential to damage the membrane. There is a
sampling port just prior to the pre-filter to collect the feed water samples. After passing through
the pre-filter, the feed water is blended with re-circulated concentrate water and is then referred
to as the inlet water. The inlet water is then sent through a booster pump and after leaving the
discharge side of the pump, the water line is split and feeds the two separate banks of membranes
-------
(three membranes per bank, six membranes in total), starting with membrane 1 and 4. For the
first bank of membranes, concentrate from membrane 1 feeds membrane 2 and concentrate from
membrane 2 feeds membrane 3. For the second bank of membranes, concentrate from
membrane 4 feeds membrane 5 and concentrate from membrane 5 feeds membrane 6. Permeate
from all membranes is collected from the bottom of the housing and exits the unit as drinking
water. There is a permeate sample port for each of the six membranes, as well as the blended
permeate from all six of the membranes. During the verification test, permeate samples were
collected from the blended permeate sample port. Concentrate from membranes 3 and 6 is split,
some being purged to waste and some re-circulating back to the head of the system, just after the
pre-filter where it is blended with the feed water to create the inlet water. The concentrate that is
re-circulated back to the head of the system is referred to as recycle water. A process flow
diagram of the flow streams through the M-15,000 RO Treatment System is presented in Figure
2-2.
Figure 2-2: Watts Premier M-15,000 RO Treatment System process flow diagram and
sample locations.
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Photograph 2: Watts Premier M-15,000 RO Treatment System at CVWD Well 7802
The recycle rate was determined during the initial shake down period, but was expected to be
75% at 130 to 150 pounds per square inch (psi) (based on the manufacturer's experience) and
was manually adjusted through a recirculation needle control valve. For a standard M-15,000
RO Treatment System, recycle ratio is not a measured operational parameter. For the verification
study, the recycle flow rate was monitored through a flow meter (not a standard part) located on
the recycle water line in order to calculate the recycle ratio and determine the tne osmotic
gradient across the membranes.
The qualitative, quantitative and cost factors of the tested equipment were identified, in so far as
possible, during the verification testing. The relatively short duration of the study created
difficulty in reliably identifying some of these factors. The qualitative factors examined during
the verification were operational aspects of the M-15,000 RO Treatment System; for example,
susceptibility to changes in environmental conditions, operational requirements and equipment
safety, as well as other factors that might impact performance. The quantitative factors
examined during the verification testing process were costs associated with the system, such as
power, filter cartridge replacement, cost of operation and disposal costs. The operating
conditions were recorded in the project logbook. Specific information regarding the membrane
plant design criteria and membrane element characteristics may be found on Table 2-1 and Table
2-2.
8
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Table 2-1: Membrane Plant Design Criteria Reporting Items
Parameter
Value
Number of Stages
Number of Pressure Vessels in Stage 1
Number of Pressure Vessels in Stage 2
Number of Membrane Elements per Pressure Vessel
Recovery per Stage (%)
Recovery for System
Design Flux
Pressure Loss per Element
Pressure Loss in Stage Entrance and Exit
Feed Stream IDS (mg/L)
IDS rejection
Rejection of Specific Inorganic Constituents
2
1
6
1
NA1
50%
12gfd2
6 psi
ISOpsi
Based on Influent Water Quality
95-99%
80-99%
1 NA = Not available.
2 Gallons per square -foot per day.
Table 2-2: Membrane Element Characteristics
Parameter
Value
Membrane Manufacturer
Membrane Element Model Number
Size of Element Used in Study
Active Membrane Surface Area per Element
Molecular Weight Cut-Off
Membrane Material Construction
Membrane Hydrophobicity
Reported Membrane Charge
Spacer Thickness
Scroll Width
Design Pressure
Design Flux at Design Pressure
Variability of Design Flux
Design Specific Flux at 25 °C
Standard Testing Recovery
Standard Testing pH
Standard Testing Temperature
Design Cross-Flow Velocity
Maximum Flow Rate to an Element
Minimum Flow Rate to an Element
Required Feed Flow to Permeate Flow Ratio
Maximum Element Recovery
Rejection of Reference Solute and Conditions of Test (e.g., Solute type and
concentration)
Variability of Rejection of Reference Solute
Acceptable Range of Operating Pressures (psi, bar)
Acceptable Range of Operating pH Values
Typical Pressure Drop across a Single Element
Maximum Permissible Silt Density Index (SDI)
Maximum Permissible Turbidity
Chlorine/Oxidant Tolerance
Suggested Cleaning Procedures
Applied
M-T4040 ALE
4" X 40"
82ft2
80- lOODaltons
Dow Filmtec
Hydrophobic
Negative
31 mil
38 inches
ISOpsi
34gfd
± 15%
0.24 gfd/psi
50-75%
8
25°C
0.6ft/s
16 gallons per minute (gpm)
4 gpm
1:5
75%
80-99%
-0%, +1%
Dependent on Water Temperature
2- 11
6 psi
4
1 NTU
With Carbon Pre -Filter
M-l 5,000 RO Treatment System
has a self-flush procedure.
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2.2 Operating Process
RO is a pressure-driven process, with the pressure used for separation by allowing fresh water to
move through a membrane, leaving various dissolved constituents of the water behind.
Scientists have explored this concept since the turn of the century, but commercialization for
desalting water for municipal purposes has occurred in only the last 30 to 40 years.
For this separation process, water from a pressurized saline solution is separated from the
dissolved inorganic and organic compounds by flowing through a membrane. No heating or
phase change is necessary for this separation. The major energy required for desalting is for
pressurizing the feed water. The saline feed water is pumped into a closed vessel where it is
pressurized against the membrane. As a portion of the water passes through the membrane, the
remaining feed water increases in salt content. At the same time, a portion of this feed water is
discharged without passing through the membrane.
The amount of water that can be passed through the membrane is frequently controlled to avoid
problems with precipitation of super-saturated salts and increased osmotic pressure across the
membranes. The amount of the feed water discharged to waste in the concentrate stream varies
from 15 to 70% of the feed low, depending on the inorganic composition of the feed water,
pressure, and type of membrane. The RO membranes vary in their ability to reject the passage
of inorganics, including the various arsenic compounds detected in the environment.
As this treatment does not destroy arsenic, the total mass of arsenic exiting the system equals the
mass entering the system. Consequently, the amount of arsenic that has been "removed" from
the permeate (treated water) can be found in the wasted concentrate.
Referring to Figure 2-1, the M-15,000 RO Treatment System used in the verification testing
included:
3 Hp single phase motor and stainless steel centrifugal pump,
Pre-filter for removal of small debris (sediment, rust, and other suspended solids) and
residual chlorine (first 18 days of testing) and a cartridge pre-treatment filter (last 13 days
of testing) (see Photograph 3),
Panel mounted flow meters (to monitor permeate, concentrate, and recycle flow),
Recycled water flow meter (not a standard part for the M-15,000 RO Treatment System)
located on the recycle line prior to cartridge pre-filter,
Manual recirculation needle control valve,
Panel mounted digital conductivity meter (permeate water),
Membrane test ports,
Glycerin filled pressure gages (used to monitor inlet and feed water pressure),
Six stainless steel pressure vessels, and
Six 4" x 40" RO modules.
10
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Photograph 3: Pre-Filter to Watts Premier M-15,000 RO Treatment System
The inlet and feed water pressure were monitored by the glycerin filled pressure gages that had a
range of 0 to 300 psi. The permeate and concentrate flow rates were measured by the panel
mounted flow meters that had a range of 0-20 gpm. The recycle flow meter also had a range of 0
to 20 gpm.
Specific feed water operating parameters, electrical and drain requirements, as well as additional
specifications for the M-15,000 RO Treatment System are presented in Table 2-3.
Table 2-3: Watts Premier M-15,000 RO Treatment System Specifications
Specifications
M-15,000 RO System
Dry Weight
Wet Weight
Feed Water Parameters
Temperature
Max Feed Flow Rate
pH
Maximum Hardness
Maximum TDS
Maximum Iron
Pressure
Drain Connection Requirements
Floor Sink Minimum within 10' of RO system
Electrical Requirements
RO Processor Optional 220V
Delivery Pump
950 Ibs
4900 Ibs
35tolOO°F
24 gpm
2 to 11
290 mg/L
2500 mg/L
0.1 mg/L
50 to 150 gauge pressure (psig)
1 %" connection
220 volts/11.5 amps
115 volts/12.4 amps
The flow rate was regulated by a flow meter and control valve to maintain a constant flow, which
were mounted on the RO control panel. Raw water was supplied to the verification testing unit
11
-------
using a pressurized feed line (approximately 80 to 90 psi) and a 3 Hp centrifugal pump was used
to increase the pressure to the RO operating conditions of -150 psi. The raw water
(approximately at 24 gpm) was first passed through a 20" carbon bloc pre-filter to remove any
small debris, other suspended solid particles, and residual chlorine. The carbon pre-filter was
replaced with a 20-micron sediment pre-filter (20 inch, Watts Premier Big Blue pleated sediment
filter; the Watts Premier poly spun sediment filter model number WP204020 may also be used)
after 18 days of operation, due to a high replacement rate (approximately every 7 days) of the
carbon pre-filter.
12
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Chapter 3
Methods and Procedures
3.1 Quantitative and Qualitative Evaluation Criteria
The objectives of the ETV were to evaluate the equipment in the following areas:
Performance relative to the manufacturer's (Watts Premier) stated range of equipment
capabilities,
The impacts on performance of variations in feed water quality (such as TDS, hardness,
temperature, pH, alkalinity and iron),
The logistical, human and economic resources necessary to operate the equipment, and
The reliability, ruggedness, cost factors, range of usefulness and ease of operation of the
equipment.
In order to address these objectives, the ETV employed the quantitative and qualitative factors
listed in Table 3-1 in evaluating the RO equipment performance.
Table 3-1: Quantitative and Qualitative Evaluation Criteria
Quantitative Factors Qualitative Factors
Flux Ease of operation
Feed water recovery Safety
Finished water quality Susceptibility to environmental conditions
Range of feed water quality that were treated Ruggedness
successfully Impact of operator experience on successful
Power consumption operation
Maintenance requirements Portability of equipment
Required level of operator attention Modular nature of equipment (ease of capacity
Spatial requirements expansion)
Feed flow requirements
Discharge requirements
Waste disposal
The primary applications of RO are the removal of dissolved inorganic and organic
contaminants. In the case of this ETV test, the primary application was arsenic removal.
3.2 Key Treated Water Quality Parameters
3.2.1 Key Groundwater Quality Parameters the Equipment is Designed to Address
The operating range of the manufacturer's RO membrane is summarized in Table 3-2.
13
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Table 3-2: Operating Range of Watts Premier RO Membrane
Parameter Range
Arsenic Less than 350
IDS Less than 2,500 mg/L
Hardness Less than 290 mg/L
Iron Less than 0.1 mg/L
pH 2 to 11
Chlorine exposure Not chlorine tolerant without a carbon filter (which was
included during a portion of the study)
1 For verification testing, the range of arsenic was anticipated to be < 50 (ig/L.
3.2.2 Key Treated Water Quality Parameters for Evaluating Equipment Performance
Key treated water quality parameters that were employed for evaluation of the manufacturer's
RO system equipment are listed in Table 3-3.
Table 3-3: Key Treated Water Quality Parameters
Water Quality Inorganic Parameters Other Parameters
Temperature Arsenic Langelier Saturation Index (LSI)
Alkalinity Conductivity SDI
Hardness Silica
pH Fluoride
Turbidity Iron
TOC Manganese
Chloride Sulfate
Free and Total Chlorine Chromium
Vanadium
TDS
TSS
Calcium
Barium
3.3 Calculations
3.3.1 Calculation of Statistical Uncertainty
The count, average, minimum, and maximum values were tabulated for all data sets. For the
water quality parameters described above, 95% confidence intervals were calculated for
parameters with more than eight data points. The following equation was used for confidence
interval calculation:
Confidence Interval = X +1
where: X = sample mean;
S = sample standard deviation;
14
-------
n = number of independent measurements included in the data set; and
t = Student's t distribution value with n-1 degrees of freedom;
oc= significance level, defined for 95% confidence as: 1-0.95 = 0.05.
According to the 95% confidence interval approach, the a term is defined to have the value of
0.05, thus simplifying the equation for the 95% confidence interval in the following manner:
( s^
95% Confidence Interval = X ±tn_l0975\ =
With input of the analytical results for pertinent water quality parameters into the 95%
confidence interval equation, the output is presented as the sample mean value plus or minus the
second term. The results of this statistical calculation are presented as a range of values falling
within the 95% confidence interval.
3. 3. 2 Calculation and Definition of Operational Parameters
The following are definitions used in the calculations presented within this section:
Permeate water is defined as the water produced by the RO membrane process.
Feed water is defined as the water introduced to the membrane element (no recycled water).
Inlet water is the combination of the feed water and the recycled concentrate water.
Concentrate water is the concentrated waste stream produce by the RO membrane process.
Recycled water is a portion of the concentrate water recirculated back through the RO membrane
process, blended with feed water entering into membranes 1 and 4.
Permeate flux is the flow of permeate divided by the surface area of the membrane.
Permeate flux was calculated according to the following formula:
(3D
where: Jt = permeate flux at time t (gfd)
Qp = permeate flow (gallons per day (gpd))
S = membrane surface area (ft2)
15
-------
Temperature Adjustment for Flux Calculation: Temperature corrections to 25°C for permeate
flux and specific flux were made to correct for the variation of water viscosity with temperature.
The following empirically derived equation was used to provide temperature corrections for
specific flux calculations:
-0.0239(1-25)
rt (at 25 °C) =
(3.2)
where: Jt = permeate flux at time t (gfd, L/(h-m2))
Qp = permeate flow (gpd, L/h)
S = membrane surface area (ft2,
T = temperature of the feed water (°C)
m2)
Net Driving Pressure: The Net Driving Pressure is the pressure available to drive water
through the membrane, equal to the average feed pressure (average of feed pressure and
concentrate pressure) minus the differential osmotic pressure, minus the permeate pressure:
NDP =
(Pf+Pc)
(3.3)
where: NDP = net driving pressure for solvent transport across the membrane (psi, bar)
Pf = inlet pressure to the feed side of the membrane (psi, bar)
Pc = concentrate pressure on the concentrate side of the membrane (psi, bar)
Pp = permeate pressure on the treated water side of the membrane (psi, bar)
ATI = osmotic pressure (psi)
Osmotic Pressure Gradient: The term osmotic pressure gradient refers to the difference in
osmotic pressure generated across the membrane barrier as a result of different concentrations of
dissolved salts. The following equation provides an estimate of the osmotic pressure across the
semi-permeable membrane through generic use of the difference in TDS concentrations on either
side of the membrane:
+TDSC)'
-TDS
I psi
100
mg
(3.4)
where: TDSi = inlet water (feed water + recycled water) TDS concentration (mg/L)
TDSC = concentrate TDS concentration (mg/L)
TDSP= permeate TDS concentration (mg/L)
The inlet water (feed water plus recycled water) characteristics were calculated based on the feed
water, permeate, and concentrate TDS and conductivity.
16
-------
Note that the different proportions of monovalent and multivalent ions composing the TDS will
influence the actual osmotic pressure, with lower unit pressures resulting from multivalent
species. The osmotic pressure ratio of 1 psi per 100 mg/L is based upon TDS largely composed
of sodium chloride. In contrast, for TDS composed of multivalent ions, the ratio is closer to 0.5
psi per 100 mg/L TDS. This was accounted for during verification testing.
Specific Flux: The term specific flux is used to refer to permeate flux that has been normalized
for the net driving pressure. The equation used for calculation of specific flux is given by the
formula provided below. Specific flux is usually discussed with use of flux values that have
been temperature-adjusted to 25°C:
(3.5)
where: NDP = net driving pressure for solvent transport across the membrane (psi, bar)
Jt = permeate flux at time t (gfd, L/(h-m2)). Temperature- corrected flux values were
employed.
Water Recovery: The recovery of feed water as permeate water is given as the ratio of
permeate flow to feed water flow:
Yo System Recovery = 100
(3.6)
where: Qf = feed water flow to the membrane (gpm, L/h)
Qp = permeate flow (gpm, L/h)
Recycle Ratio: The recycle ratio represents the ratio of the recycle flow from the membrane
concentrate to the total flow of water that is used as feed water flow to the membrane. This ratio
provides an idea of the recirculation pumping that is applied to the membrane system to reduce
membrane fouling and specific flux decline.
Q,
RecycleRation=
(37)
where: Qr = recycle water flow rate (gpm)
Qf = feed water flow rate (gpm)
17
-------
Solute Rejection: Solute rejection is controlled by a number of operational variables that must
be reported at the time of water sample collection. Bulk rejection of a targeted inorganic
chemical contaminant were calculated by the following equation:
% Solute Rejection = 100
(3.8)
where: Cf = feed water concentration of specific constituent (mg/L)
Cp = permeate concentration of specific constituent (mg/L)
Note: the feed water concentration does not include the recycled water.
Solvent and Solute Mass Balance: Calculation of solvent mass balance was performed during
Task 1 in order to verify the reliability of flow measurements through the membrane.
Calculation of solute mass balance across the membrane system was performed as part of Task 3
in order to estimate the concentration of total arsenic at the membrane surface.
Qf=QP + Qcw (3.9)
QfCf=QpCp + QcwCc (3.10)
where: Qf = feed water flow to the membrane (gpm, L/h)
Qp = permeate flow (gpm, L/h)
Qcw = concentrate (wastewater) flow (gpm, L/h)
Cf = feed water concentration of specific constituent (mg/L)
Cp = permeate concentration of specific constituent (mg/L)
Cf = concentrate concentration of specific constituent (mg/L)
Solubility Product: Calculation of the solubility product of selected sparingly soluble salts was
performed to determine if there were operational limitations caused by the accumulation of
limiting salts at the membrane surface. Textbook equilibrium values of the solubility product
were compared with solubility values calculated from the results of experimental verification
testing, as determined from use of the following equation:
(3.H)
where: Ksp = solubility product for the limiting salt being considered
y = free ion activity coefficient for the ion considered (i.e., A or B)
[A] = molar solution concentration of the anion A for sparingly soluble salt AxBy
[B] = solution concentration of the anion B
x, y = stiochiometric coefficients for the precipitation reaction of A and B
18
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Mean Activity Coefficient: The mean activity coefficients for each of the salt constituents were
estimated for the concentrated solutions as a function of the ionic strength:
lagyAJI= -0.509-
(3.12)
where: y = free ion activity coefficient for the ion considered (i.e., A or B)
ZA = ion charge of anion A
ZB = ion charge of cation B
(j, = ionic strength
Ionic Strength: A simple approximation of the ionic strength was calculated based upon the
concentration of the IDS in the feed water stream:
(3.13)
where: (J, = ionic strength
IDS = total dissolved solids concentration (mg/L)
3.4 Testing Schedule
The ETV schedule is presented in Figure 3-1. The testing took place over a total period of
approximately eight weeks beginning during the second week of April 2004, and ending in late
May 2004. The five tasks are described in further detail in Sections 3.7 and 4.1.
Task
1
2
3
4
5
Descrintion
Preparation, Coordination, and Setup
Membrane Operation
Cleaning Efficiency
Feedwater and Treated Water Quality Monitoring
Data Handling Protocol
Quality Assurance Project Plan
Year - 2004
12-Acr 19-Acr 26-Acr 3-Mav 10-Mav 17-Mav 24-Mav 7-Jun
I
I
Figure 3-1: RO verification testing schedule.
Verification testing activities included equipment set-up, initial operation, verification operation,
membrane cleaning, and sampling and analysis. Initial operations were conducted so that
equipment could tested and to be sure it is functioning as intended.
19
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3.5 Operation and Maintenance
The manufacturer's operation and maintenance (O&M) documentation for the M-15,000 RO
Treatment System was reviewed prior to the verification testing. The O&M manual for the M-
15,000 RO Treatment System may be found in Appendix A of this report. In addition, the
following aspects of operability are addressed in this report:
Fluctuation of flow rates and pressures through membrane unit - the time interval at
which resetting is needed (i.e., how long can feed pumps hold on a set value for the feed
rate?)
Presence of devices to aid the operator with flow control adjustment?
Was transmembrane pressure measurement provided?
Was recycle ratio measurement provided?
Was feed water recovery measurement provided?
Was rate of flow of raw water measured?
Did the plant have an indicator if the sediment pre-filter was changed ahead of scheduled
quarterly maintenance schedule?
Did the carbon pre-filter adequately remove chlorine?
3.6 Field Operations Procedures
Testing of the M-15,000 RO Treatment System was conducted by an NSF-qualified FTO, MWH.
Water quality analytical work that was carried out as a part of the verification testing plan, was
conducted by MWH Laboratories. All arsenic analyses were conducted by MWH Laboratory.
Field analytical work was performed by MWH field personnel using field laboratory equipment
and procedures for pH, temperature, conductivity, chlorine, turbidity, alkalinity, and hardness.
The verification unit was operated 24 hours a day, seven days a week with staff on-site each day
to operate the verification unit and collect water quality data during one eight-hour shift. Tasks
performed by the operations staff are described in detail below.
3.7 Environmental Technology Verification Testing Plan
The following section provides a brief overview of the tasks included in the initial
characterization tests and the tasks included in the M-15,000 RO Treatment System verification
testing plan. The verification tasks included:
Task 1: Membrane Operation
Task 2: Cleaning Efficiency
Task 3: Feed water and Treated Water Quality Monitoring
Task 4: Data Handling Protocol
Task 5: Quality Assurance Project Plan (QAPP)
Verification testing activities included equipment set-up, initial operation, verification operation,
and sampling and analysis. Initial operations were conducted so that equipment could be tested
20
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to be sure it was functioning as intended. An overview of each task is provided below with
detailed information following this section of the report.
3.7.1 Task 1: Membrane Operation
The objective of this task was to evaluate the RO membrane system operation. System
performance was evaluated relative to the stated water quality goals specified by the
manufacturer. Membrane productivity, rate of specific flux decline, and rejection capabilities
were evaluated at one set of operating conditions for the testing period.
3.7.2 Task 2: Cleaning Efficiency
The objective of this task was to evaluate the efficiency of the membrane cleaning procedures
recommended by the manufacturer. Watts Premier recommends replacement of the RO modules
based upon efficiencies of TDS reduction per module. TDS reduction of the membranes would
need to be monitored in order to determine if replacement of the membranes is necessary. Watts
has stated that the M-15,000 RO Treatment System has a built in flushing procedure; however,
since the verification test was run continuously, the system did not go through this flushing
procedure. However, at the conclusion of the testing period, the cartridge sediment pre-filter and
RO module O-rings were replaced according to the manufacturer's recommended quarterly
maintenance procedures. While not part of the quarterly maintenance procedures, two of the
membranes (membrane number 5 and 6) were also replaced during the maintenance procedures.
The operational performance following these maintenance procedures was recorded and
presented in Chapter 4 of this report.
3.7.3 Task 3: Feed Water and Treated Water Quality Monitoring
The objective of this task was to evaluate the quality of water produced by the membrane system
and the removal of inorganic chemical contaminants achieved by the membrane system at the
specified operational conditions. Monitoring of the water quality parameters included the
following: arsenic (total, dissolved and As (III)), pH, feed water temperature, chloride,
conductivity, calcium, barium, hardness, chlorine, TDS, alkalinity, LSI, turbidity, TSS, silica,
fluoride, iron, manganese, sulfate, chromium, vanadium, TOC and SDL Water quality produced
was evaluated in relation to feed water quality and operational conditions. Mass balances were
calculated to determine the accumulation of limiting salts on the membrane surface. Post-
treatment capabilities of the equipment were also evaluated for arsenic (total, As+3, and
dissolved), pH adjustment, corrosion control, and removal of carbon dioxide from the permeate.
An overview of the equipment operational and production characteristics evaluated for each task
of the verification testing is provided in Table 3-4.
21
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Table 3-4: Equipment Operational Characteristics to be Evaluated in Each Task
Equipment Operational Characteristic to be Evaluated Task
1.
2
3.
4.
5.
6.
7.
8.
9.
10.
11.
Feed water flow rate
Permeate flow rate
Concentrate flow rate
Inlet and Outlet pressures to membrane element
Permeate pressure
Feed water temperature
Recycle Ratio
Power consumption
Permeate stream characterization
Calculation of limiting salt concentrations
Waste stream characterization and range of waste stream flow rates
1
1
1
1
1
1
1
1
3
o
J
1 and 3
3.7.4 Task 4: Data Handling Protocol
The objective of this task was to establish an effective field protocol for data management at the
field operations site and for data transmission between the FTO and NSF during verification
testing. Prior to the beginning of field testing, the database or spreadsheet design were
developed by the FTO and reviewed and approved by NSF. This insured that the required data
was collected during the testing, and that results could be effectively transmitted to NSF for
review.
3.7.5 Task 5: Quality Assurance Project Plan (QAPP)
An important aspect of verification testing is the Quality Assurance Project Plan (QAPP)
developed for QA/QC. The objective of this task was to assure accurate measurement of
operational and water quality parameters during membrane equipment verification testing.
3.8 Task 1: Membrane Operation
Membrane operation was evaluated in Task 1, with quantification of temperature-corrected rate
of specific flux decline and water recoveries. The rates of specific flux decline were used to
demonstrate membrane performance at the specific operating conditions to be verified.
Monitoring in Task 1 was focused on determination of the system operational characteristics
(e.g., arsenic removal, flux, temperature-corrected specific flux, recovery, etc.). An NSF field
inspection of equipment operations, sampling, and field analysis procedures was carried out
during the initial test runs in Task 1 (results presented in Chapter 4).
Rate of temperature-corrected specific flux decline is a function of water quality and operational
strategy. Many additional factors influence specific flux decline with RO membranes including
membrane compaction, inorganic scaling, particulate or organic fouling, biofouling, and other
factors. In this task, specific flux decline was monitored to evaluate operational trends.
Chemical characterization of the feed waters and permeate water stream with calculation of
membrane rejection capabilities were performed as part of Task 3. Additionally, calculation of
the operational limitations caused by limiting salt concentrations was also performed in Task 3.
22
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3.8.1 Experimental Objectives
The objectives of Task 1 were to demonstrate the following: 1) the appropriate operational
conditions for the membrane equipment; 2) the feed water recovery achieved by the membrane
equipment at the designated operational conditions; and 3) tie rate of specific flux decline
observed over extended membrane filtration operation during the testing period. This task was
also intended to provide operational power consumption information that could be used to
develop cost estimates for O&M of the equipment. Complete chemical and physical
characterization of the feed waters and treated waters produced by the system, with calculation
of limiting salt concentrations, were performed as part of Task 3.
It should be noted that the objective of this task was not process optimization, but rather
verification of membrane operation at the operating conditions specified by the FTO, as pertains
to permeate flux and transmembrane pressure.
3.8.2 Work Plan
Site preparation, coordination, mobilization and start-up of equipment were performed prior to
the initiation of Task 1 testing. Furthermore, the RO membrane treatment system had achieved a
condition of steady-state operation prior to the start of Task 1 testing.
After set-up and shakedown of the membrane equipment, RO operation was established at a
specific flux of 0.38 gfd/psi with a feed water recovery of 69%. It was intended that the
membrane system would be operated continuously for a minimum of one month. However, the
system automatically shut itself down twice during the verification testing, and was not in
operation for a total of four days during the verification testing period. The system was operated
for a total of 27 days during the verification test. A summary of the operational parameters
recorded during Task 1 and the minimum frequency of monitoring are presented in Table 3-5. A
summary of the water recovery and specific flux may be found in Tables 4-3 (Section 4.2.1.3)
and Table 4-6 (Section 4.2.1.5) respectively.
Samples were collected from lab valves mounted on the panel coming from Vi" ball valves teed
into the permeate line (permeate), 1" bulk fittings mounted on the top of the unit (concentrate),
1" port on the top of the unit (inlet), and a 1" housing on the side of the panel (feed water). The
inlet and feed water pressure were monitored by the glycerin filled pressure gages that have a
range of 0 to 300 psi, and the permeate and concentrate flow rates were measured by the panel
mounted flow meters that have a range of 1 to 20 gpm. For a standard M-15,000 RO Treatment
System, the recycle ratio is not a measured operational parameter. However, for the purpose of
verification testing, a flow meter was placed on the recycle line to calculate the recycle ratio.
23
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Table 3-5: Frequency and Type of Operating Data
Operational Parameter
Action, Monitoring Frequency
Feed Water, Permeate, Recycle, and Concentrate Flow
Rates
Membrane Element Inlet and Feed Water Pressures
Recovery
Recycle Ratio
IDS Concentration in Feed water, Concentrate,
Permeate
Feed water Temperature
Horsepower and Efficiency of Motors, and Consumed
Amperage for RO Treatment
Concentrate Composition For Disposal
Checked and recorded twice daily. Adjusted when 10%
above or below target. Recorded both before and after
adjustment. The feed water flow rate was monitored
twice daily by summing the permeate and concentrate
flow rates.
Checked and recorded twice daily.
Calculated and recorded twice daily. Adjusted when
10% above or below target.
Calculated and recorded twice daily. Adjusted when
10% above or below target.
Calculation of osmotic pressure gradient on a daily
basis.
Recorded twice daily.
Provided record of pumping requirements, current draw
to motors on cumulative basis, power factor and
recorded daily from a power totalizer.
Sampled waste stream once per week during the 31 -day
testing period.
When a specific flux decline of 20% occurred before the operating period was completed,
adjustments to the operational strategy were made (such as a decrease in nominal flux or
recovery). Decisions on which adjustments were made were based upon the manufacturer's
experience and consultation with the FTO conducting the study.
3.8.3 Analytical Schedule
Measurement of membrane performance parameters were monitored a minimum of 2 times per
day, as indicated in Table 3-5. Temperature measurements were made on a daily basis in order
to provide data for temperature correction of specific flux and for reporting of solute rejection
(addressed in Task 3).
Power use for the operation of the RO system was monitored with a power totalizer. Power
measurements were recorded daily by MWH during the verification test.
The characteristics of feed waters used during the testing period were explicitly reported with the
compiled results from membrane flux, specific flux and recovery monitoring. The TDS
concentrations in the inlet water (combined feed water and recycled water), permeate and
concentrate streams were used to calculate the osmotic pressure gradient (Equation 3.4) across
the membrane on a daily basis. Osmotic pressure gradient value was used to calculate net
driving pressure and specific flux on a daily basis.
3.8.4 Evaluation Criteria and Minimum Reporting Criteria
General operational performance (provided in Chapter 4):
=> Graph of specific flux normalized to 25°C (Equation 3.5) vs. time over the
verification testing period.
24
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=> Temporal profile of net driving pressure normalized to 25°C (Equation 3.3) over
the verification testing period.
=> Temporal profile of water recovery (Equation 3.6) over the verification testing
period. One temporal profile graph has been provided for the water quality
evaluated.
=> Temporal profile of the concentrate flow and other waste stream flows produced
during the verification testing period.
Power consumption (provided in Chapter 4):
=> A table of horsepower requirements, motor efficiency and consumed amperage for
the testing period has been provided, as measured for the set of operational
conditions during the verification testing period.
Concentrate stream characterization (See Chapter 4, Task 3 for the water quality
characteristics of the concentrate, permeate, and feed water):
=> A table of concentrate stream quality parameters measured during the verification
testing period has been provided.
3.9 Task 2: Cleaning Efficiency
While no chemical cleaning procedure was provided by the manufacturer, regularly scheduled
maintenance of the system includes quarterly replacement of the pre-filter and RO module O-
rings, and replacement of the BD modules based on efficiencies of TDS reduction per filter
module. At the end of the testing period, the cartridge sediment pre-filter and RO module O-
rings were replaced. In addition to replacing the pre-filter and RO module O-rings, two of the
membranes were replaced (membrane number 5 and 6). Measurement of membrane
performance parameters following this maintenance were recorded and presented in Chapter 4.
3.9.1 Experimental Objectives
The objective of this task was to evaluate the manufacturer's recommended maintenance
procedures for ensuring reasonable operational parameters are maintained during throughout the
treatment life of the membrane modules. This task was considered a "proof of concept" effort,
not an optimization effort.
3.9.2 Work Plan
The membrane system has the potential to experience specific flux decline during the membrane
test run conducted for Task 1. If a 20% decline of specific flux were detected, the modules were
to be replaced and the system would then undergo the recommended maintenance procedures
specified by the manufacturer. Following the maintenance procedures, the system was restarted
and the initial conditions of specific flux, recovery and inorganics (arsenic) rejection capabilities
were tested.
As the manufacturer recommends replacement of fouled modules, no chemical cleaning
procedures were provided. Furthermore, since chemical cleanings are not recommended,
disposal of spent cleaning agents is not relevant.
25
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3.9.3 Analytical Schedule
Flow rates, pressures, recovery, and temperature data were collected immediately prior to and
immediately after performing any manufacturer's scheduled quarterly or annual maintenance
procedures. Based on this information, any changes in the temperature adjusted specific flux
were determined. Two primary indicators of conventional cleaning efficiency and restoration of
membrane productivity were examined in this task:
1) The immediate recovery of membrane productivity, as expressed by the ratio between the
final specific flux ralue of the current filtration run (Jtmf) and the initial specific flux (Jtm;)
measured for the subsequent filtration run:
"/
% Recovery of specific Flux =100
tm /
(3.14)
where: Jtmf = Final specific flux (gfd/psi, L/(h-m2)/bar) at end of the previous run
Jtmi = Initial specific flux (gfd/psi, L/(h-m2)/bar) at the beginning of the current
run.
2) The loss of specific flux capabilities, as expressed by the ratio between the initial specific
flux for any given filtration run (Jtmi) divided by the original specific flux measured at the
initiation of operation for the first filtration run in a series (Jtmio):
% Loss of Original specific Flux =100
Jt,
(3.15)
where: Jtmio = Original Specific flux (gfd/psi, L/(h-m2)/bar) measured at the initiation of
membrane testing.
3.9.4 Evaluation Criteria and Minimum Reporting Requirements
The minimum reporting requirements include presentation of the following results
Specific flux recovery:
=> A table is provided in Chapter 4 of post maintenance specific flux recoveries
during the period of operation.
Maintenance efficiency:
=> A table is provided in Chapter 4 of the maintenance efficiency indicators
described above for the maintenance procedures performed during the period of
operation.
Assessment of irreversible loss of specific flux and estimation of usable membrane life
for costing purposes.
26
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3.10 Task 3: Water Quality Monitoring
The water quality data for the feed water (chlorinated groundwater), the membrane permeate and
concentrate streams were collected during the verification testing as part of Task 1. A list of the
water quality parameters monitored during equipment verification testing is provided in Table 3-
6.
Table 3-6: Sampling Schedule and Methods for Feed, Permeate, & Concentrate Water
Parameter
Arsenic (total)
Arsenic (As+3 and dissolved)
pH
Conductivity
TDS
Alkalinity
Hardness
LSI
Turbidity
Temperature (feed only)
TSS
Silica
Calcium
Barium
Fluoride
Iron
Manganese
Sulfate
Chlonde
Chromium
Vanadium
TOC
SDI4
Chlorine (total and free)5
Frequency1
I/day
I/week
I/day
2/day
I/day
I/week
I/week
1 /month
I/week
2/day
I/week
I/week
I/week
I/week
I/week
I/week
I/week
I/week
I/week
I/week
I/week
I/week
1 /month
4/week
Facility
Laboratory
Laboratory
On-site
On-site
Laboratory
On-site
On-site
By Calculation
On-site
On-site
Laboratory
Laboratory
Laboratory
Laboratory
Laboratory
Laboratory
Laboratory
Laboratory
Laboratory
Laboratory
Laboratory
Laboratory
Laboratory
On-site
Standard
Method2
4500-H+ B
2510 B
2540 C
2130 B
2550
2540 D
4500 FC
5310 C
ASTM
D4189-95
EPA
Method3
200.8
200.8
200.7
200.7
200.8
200.7
200.8
300.0
300.0
200.8
200.8
Hach
Method
8221
8226
8167 (total)
8021 (free)
1 The verification plant was staffed seven days per week.
2 Standard Methods 20th Edition.
^ "IVTptliork for trip Fiptprminfltio-
n of IVTptnls in
Fnvironmpritfll Siarr
mlp^-Sliirvnlpmpr
it T" FPA/finn/i
R-Q4/111 Mnv 1 QQ4
Available at (NTIS) PB95-125472.
4 SDI was analyzed on the feed water only.
5 Total and free chlorine were monitored prior to the pre-filter and after the first membrane to monitor the chlorine removal.
3.10.1 Experimental Objectives
The objective of this task was to assess the treatment capability of the membrane equipment to
remove arsenic based on water quality conditions at the site. Mass balances were performed as
part of this task in order to evaluate the concentration of rejected species at the membrane
surface during membrane operation. Calculation of the recovery limitation caused by limiting
salts was performed to determine the impact of feed water quality on membrane operation. The
count, average, minimum, and maximum values were tabulated for all data sets. Statistical
analysis (standard deviation and confidence intervals), were performed on all analytes with eight
27
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or more discrete samples collected over the verification period. The median, minimum,
maximum, and count were presented for each pH data set.
3.10.2 Work Plan
Monitoring of water quality parameters in the feed water, permeate and concentrate water
streams allowed the calculation of percent rejection of the measured parameters and targeted
inorganic chemical contaminants for the specific operational conditions evaluated. Estimation of
the percent rejection of arsenic (total) was based upon the equation for solute rejection provided
in the Section 3.3.2, Equation 3.8.
Many of the water quality parameters described in this task were measured on-site by the NSF-
qualified FTO. Analysis of the remaining water quality parameters were performed by MWH
Laboratories, a state certified laboratory. The methods used for measurement of water quality
parameters are identified in Table 3-6. A number of the analytical methods utilized in this study
for on-site monitoring of feed, permeate, and concentrate water qualities are further described in
Task 5, Quality Assurance Project Plan. These analytical methods include pH, conductivity,
turbidity, alkalinity, hardness, chlorine, and temperature.
For the water quality parameters submitted to MWH Laboratories, water samples were collected
in appropriate containers (containing necessary preservatives as applicable) prepared by MWH
Laboratories. These samples were then preserved, stored, shipped, and analyzed in accordance
with appropriate procedures and holding times.
3.10.3 Analytical Schedule
Feed Water, Permeate and Concentrate Characterization
During the testing period, the feed water, permeate and concentrate water streams were
characterized at a single set of operating conditions. The water quality monitoring requirements
are provided in Table 3-6.
Water Quality Sample Collection
Water quality data were collected at the specified intervals during each testing period. The
monitoring frequency for the water quality parameters is provided in Table 3-6. To the extent
possible, analyses for inorganic water quality parameters were performed on water sample
aliquots obtained simultaneously from the same sampling location, in order to ensure the
maximum degree of comparability between water quality analytes.
The TDS concentrations in the feed water, permeate and concentrate streams were used to
calculate the ionic strength of the feed water and concentrate streams, as well as osmotic pressure
gradient across the membrane on a daily basis (see Chapter 4). Osmotic pressure gradient value
was then used for calculation of net driving pressure and specific flux on a daily basis. Mass
balances for specified water quality parameters [arsenic (total, As+3, and dissolved), silica,
fluoride, iron, manganese, chloride, barium, calcium and sulfate] were then calculated once per
week. Calculation of the potential for recovery limitation based upon limiting salt concentrations
was performed once per week.
28
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3.10.4 Evaluation Criteria and Minimum Reporting Criteria
Percent removal of inorganic chemical constituents were developed and the following are
presented in Chapter 4:
=> A temporal plot showing concentrations of target inorganic constituents (arsenic,
silica, fluoride, iron, chloride and sulfate) and TDS in the feed water, permeate
and concentrate water streams over the period of operation is presented. A
temporal plot of the manganese concentrations was not presented as all results
(feed water, permeate, and concentrate) were below the minimum reporting limit
(MRL)of2.0ng/L.
=> A table with weekly values of percent removal of target inorganic constituents
[arsenic (total, As+3, As+5 and dissolved), silica, fluoride, iron, manganese,
chloride, barium, calcium and sulfate] and other pertinent water quality
parameters (chromium and vanadium) for the period of operation is presented.
The equations shown in Section 3.3.2 were used to determine percent removal of
all pertinent water quality parameters for verification testing.
=> Mass balances through the membrane testing system for total arsenic were
conducted. The mass balance equation presented in the Section 3.3.2 was used to
calculate the mass of inorganic constituents in different water streams.
=> Limiting salt concentrations (via solubility product calculation Equation 3.11)
were calculated for specific water quality constituents (CaCCh, BaSO/t, and
CaSO/t) once per week. The equation for solubility product calculation as
presented in Section 3.3.2 (Equation 3.11) were used to compare with standard
Solubility Product values to determine if the salt concentration is posing a
limitation to operational system recovery.
Individual water quality and removal goals specified by the manufacturer:
=> Feed, permeate and concentrate concentrations of any measured water quality
parameters are provided in tabular form for the period of operation.
Removal of TSS and Turbidity:
=> A table of feed, permeate, and concentrate water measurements are presented for
TSS during the period of operation.
=> A table of feed, permeate, and concentrate water turbidity measurements are
presented for the period of operation.
3.11 Task 4: Data Handling Protocol
The data management system used in the verification testing involved the use of both computer
spreadsheets and manual recording (on-site logbook) of operational parameters for the
membrane equipment on a daily basis. All field activities were thoroughly documented. Field
documentation included field notebooks, photographs, field data sheets, and chain-of-custody
forms. The following guidelines were followed:
Field notes were kept in a bound logbook,
Field logbook was used to record all water treatment equipment operating data,
Each page was sequentially numbered,
Each page was labeled with the project name and number,
29
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Completed pages were signed and dated by the individual responsible for the entries, and
Errors had one line drawn through them and this line was initialed and dated.
All photographs were logged in the field logbook. These entries included the time, date, and
subject of the photograph, and identified the photographer.
Original field sheets and chain-of-custody forms accompanied all samples shipped to the
analytical laboratory. Copies of field sheets and chain-of-custody forms for all samples are
included in Appendix C.
3.11.1 Experimental Objectives
The objectives of this task were: 1) to establish a viable structure for the recording and
transmission of field testing data such that the FTO provided sufficient and reliable data to NSF
for verification purposes, and 2) to develop a statistical analysis of the data, as described in the
document "EPA/NSF ETV Protocol for Equipment Verification Testing for Removal Of
Inorganic Constituents: Requirements For All Studies" and "EPA/NSF ETV Protocol for
Equipment Verification Testing for Arsenic Removal: Requirements For All Studies."
3.11.2 Work Plan
FTO operators recorded data and calculations by hand in laboratory notebooks. Daily
measurements were recorded on specially prepared data log sheets as appropriate. The original
notebooks were stored on-site; and electronic copies were forwarded to the project manager of
the FTO at least once per week during the testing period. Operating logs included a description
of the membrane equipment (description of test runs, names of visitors, description of any
problems or issues, etc.); such descriptions were provided in addition to experimental
calculations and other items.
A database for the project was set up in the form of custom-designed spreadsheets. The
spreadsheets were capable of storing and manipulating each monitored water quality and
operational parameter from each task, each sampling location, and each sampling time. All data
from the laboratory notebook and data log sheets were entered into the appropriate spreadsheet.
Data entry was conducted on-site by the designated field testing operators. All recorded
calculations were also checked at this time. Following data entry, the spreadsheets were printed
out and the printouts were checked against the handwritten data sheet. Any corrections were
noted on the hard copies and corrected on the screen, and then a corrected version of the
spreadsheet was printed out. Each step of the verification process was initialed by the field
testing operator performing the entry or verification step.
Data from MWH Laboratory were received and reviewed by the field-testing operator. These
data were entered into the data spreadsheets, corrected, and verified in the same manner as the
field data. As available, electronic data storage and retrieval capabilities were employed in order
to maximize data collection and minimize labor hours required for monitoring.
30
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3.12 Task 5: Quality Assurance Project Plan (QAPP)
QA/QC of the operation of the membrane equipment and the measured water quality parameters
were maintained during verification testing through a quality assurance project plan (QAPP) as
described in this section.
3.12.1 Experimental Objectives
The objective of this task was to maintain strict QA/QC methods and procedures during
verification testing. Maintenance of strict QA/QC procedures was important, in that if a question
arose when analyzing or interpreting data collected for a given experiment, it was possible to
verify exact conditions at the time of testing. The elements of the Quality Assurance Project
Plan for the ETV included:
Work Plan,
Monthly QA/QC Verifications,
Data Correctness,
Calculation of Indicators of Data Quality, and
Corrective Action Plan.
3.12.2 Work Plan
Equipment flow rates were measured and recorded on a daily basis. A routine daily walk through
during testing was established to verify that each piece of equipment or instrumentation was
operating properly. In-line monitoring equipment such as flow meters, etc. were checked to
confirm that the readout matches with the actual measurement (i.e. flow rate).
3.12.3 Monthly QA/QC Verifications
The monthly QA/QC verifications included:
Differential pressure transmitters (verify gauge readings and electrical signal using a
pressure meter) and
Tubing (verify good condition of all tubing and connections; replace if necessary).
3.12.4 Data Correctness
Data correctness refers to data quality, for which there are five indicators:
Representativeness,
Statistical Uncertainly,
Precision,
Accuracy, and
Completeness.
-------
3.12.4.1 Representativeness
As specified by NSF, representativeness of water quality samples for the ETV were ensured by
executing consistent sample collection procedures, including:
Sample locations,
Timing of sample collection, and
Analytical methods, sampling procedures, sample preservation, packaging and transport.
Sample Locations
Sample locations for the Ml5,000 RO Treatment System included the feed water, permeate
(treated water), and concentrate. Only one specific sample tap was used at each of these sample
locations.
Timing of Sample Collection
In the RO verification study, the timing of sample collection was not as critical as in, for
example, a granular media filtration verification study in which the filter run time can influence
the quality of water produced by the filter. For the BD verification study, there is no filter
maturation time, stable period of filter operation, or turbidity breakthrough period. To the extent
possible, analyses for inorganic water quality parameters were performed on water sample
aliquots obtained simultaneously from the same sampling location, in order to ensure the
maximum degree of comparability between water quality analytes.
Analytical Methods, Sampling Procedures, Sample Preservation, Packaging and Transport
The analytical methods and sampling procedures utilized in the verification testing plan for
collecting laboratory samples and for on-site monitoring of feed water, permeate and concentrate
water quality are described below. Field analyses were performed using portable field analytical
equipment. Laboratory samples were collected in bottles prepared by MWH Laboratories with
the appropriate preservative for the analyte. Once collected, the samples were stored in a
refrigerator (4°C) until ready for transport to MWH Laboratories, and the temperature of the
refrigerator were logged daily. The samples were transported in coolers packed with ice. With
the exception of those samples noted in Chapter 4, the samples were analyzed within the
Standard Methods or EPA recommended holding times, if not analyzed on-site.
Samples were collected from lab valves mounted on the panel coming from Vi" ball valves teed
into the permeate line (permeate), 1" bulk fittings mounted on the top of the unit (concentrate),
and a 1" housing on the side of the panel (feed water). To the extent possible, analyses for water
quality parameters were performed on water sample aliquots obtained simultaneously from the
same sampling location, in order to ensure the maximum degree of comparability between water
quality analytes.
Arsenic (Total)
Samples were collected headspace free into polyethylene or borosilicate glass bottles
provided by the analytical laboratory, capped tightly and stored refrigerated. The sample
bottles from the laboratory included the preservative (HNOs) for a holding period of up to
32
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six months. The samples were analyzed using EPA Method 200.8 within the holding
period of the preserved samples.
Arsenic (As (III) and Dissolved)
Samples were collected on-site and speciated using the procedures (see Appendix B) and
resin columns provided by NSF. The samples were collected in polyethylene bottles
provided by MWH Laboratories (preserved in accordance with the NSF procedures).
The samples were analyzed using EPA Method 200.8 within the holding period of the
preserved samples (six months).
pH
Analyses for pH were performed according to Standard Method 4500-H+B. Samples
were collected and analyzed on-site immediately and the temperature at which the pH
readings were made was recorded. Sample agitation and prolonged exposure to air were
avoided. A three-point calibration of the pH meter used in this study was performed once
per day when the instrument was in use. Certified pH buffers (4.0, 7.0, and 10.0) were
used for the daily calibration. The probe was stored in the appropriate solution defined in
the instrument manual.
Conductivity
Analyses for conductivity were performed according to Standard Method 2510 B.
Samples were collected and analyzed on-site immediately. Sample agitation and
prolonged exposure to air were avoided. A three-point calibration of the conductivity
meter used in verification testing was performed once per day when the instrument is in
use. Certified conductivity solutions (184, 1000, and 1990 umoh/cm) and were used.
The probe was stored in the appropriate solution defined in the instrument manual.
Turbidity
Due to the relatively short holding period of 48-hours, these samples were analyzed on-
site using Standard Method 2130 B with a bench-top turbidimeter. All glassware used
for turbidity measurements were cleaned and handled using lint-free tissues to prevent
scratching. Sample vials were stored inverted to prevent deposits from forming on the
bottom surface of the cell.
The bench-top turbidimeter was calibrated within the expected range of sample
measurements at the beginning of equipment operation and on a weekly basis using
primary turbidity standards of 0.1, 0.5, and 5.0 Nephelometric Turbidity Units (NTU).
The turbidity meter has a range of 0 to 199 NTU. Secondary turbidity standards were
obtained and checked against the primary standards. Secondary standards were used
(4.5, 45.9, and 448 NTU) on a weekly basis to verify calibration of the turbidimeter and
to re-calibrate when more than one turbidity range was used.
The method for collecting grab samples was performed according to the following
protocol: 1) running a slow, steady stream from the sample tap, 2) triple-rinsing a
dedicated sample beaker in this stream, 3) allowing the sample to flow down the side of
the beaker to minimize bubble entrainment, 4) double-rinsing the sample vial with the
sample, 5) carefully pouring from the beaker down the side of the sample vial, 6) wiping
33
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the sample vial clean, 7) inserting the sample vial into the turbidimeter, and 8) recording
the measured turbidity. There were no issues associated with fogging of the glass vials.
Chlorine
Free and total chlorine were analyzed in the feed water (before the pre-filter) and after the
pre-filter to monitor for chlorine removal. There was no sample port between the pre-
filter and the first membrane; therefore, chlorine was tested after the first membrane.
Analyses for both free and total chlorine were conducted on-site immediately upon
collection of the samples, using Hach's DPD method of analysis, 8167 for total chlorine
and 8021 for free chlorine (both EPA approved methods).
Alkalinity and Hardness
Alkalinity (bicarbonate) and hardness were not target contaminants for arsenic removal
by RO. Thus, they were measured on-site by properly calibrated test kits provided by
Hach. Total alkalinity was measured on-site immediately using Hach's 0.1600 N sulfuric
acid with Hach's titration method (Hach method 8221) with a detection range of 0 to
5,000 mg/L as CaCO3. Total hardness was measured on-site immediately using Hach's
titration method prepared titrants (EDTA Hach method 8226), with a range of 0 to 25,000
mg/LasCaCO3.
All test kits used on-site were calibrated when the equipment was in use, utilizing known
standards at two or more concentration levels. Data obtained with test kits, which utilize
non-standard methods were not used to determine if the system met the applicable
performance criteria.
Temperature
Readings for temperature were conducted on-site immediately after collection in
accordance with Standard Method 2550. Raw water temperatures were obtained twice
daily. The thermometer was a precision thermometer certified by the National Institute
of Standards and Technology (NIST).
TDS
Plastic sample bottles were used, as provided by the analytical laboratory. Analyses were
made as soon as possible due to impracticality of preserving samples, as specified in
Standard Method 2540. Samples were refrigerated until the time of analysis.
TSS
Plastic sample bottles were used, as provided by the analytical laboratory. Analyses were
made as soon as possible due to impracticality of preserving samples, as specified in
Standard Method 2540 D. Samples were refrigerated until the time of analysis.
TOC
Amber glass bottles preserved with H2SO4 were used, as provided by the analytical
laboratory. Analyses were made as soon as possible according to Standard Method 5310
C. Samples were refrigerated until the time of analysis, prior to the 28-day holding
period.
34
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Iron
Samples were collected headspace free into polyethylene bottles provided by the
analytical laboratory, capped tightly and stored refrigerated. The sample bottles from the
laboratory included the preservative (HNCb) for a holding period of up to six months.
All iron samples were analyzed using EPA Method 200.7 within the holding period of the
preserved samples.
Manganese
Samples were collected headspace free into polyethylene bottles provided by the
analytical laboratory, capped tightly and stored refrigerated. The sample bottles from the
laboratory included the preservative (HNOs) for a holding period of up to six months.
All manganese samples were analyzed using EPA Method 200.8 within the holding
period of the preserved samples.
Sulfate
Samples were collected headspace free into polyethylene bottles provided by the
analytical laboratory, capped tightly and stored refrigerated. All sulfate samples were
analyzed using EPA Method 300.0 within the holding period of the preserved samples.
Chloride
Samples were collected headspace free into polyethylene bottles provided by the
analytical laboratory, capped tightly and stored refrigerated. All chloride samples were
analyzed using EPA Method 300.0 within the holding period of the preserved samples.
Silica
Samples were collected headspace free into polyethylene bottles provided by the
analytical laboratory, capped tightly and stored refrigerated. The sample bottles from the
laboratory included the preservative (HNCb) for a holding period of up to six months.
All silica samples were analyzed using EPA Method 200.7 within the holding period of
the preserved samples.
Chromium
Samples were collected headspace free into polyethylene bottles provided by the
analytical laboratory, capped tightly and stored refrigerated. The sample bottles from the
laboratory included the preservative (HNOs) for a holding period of up to six months.
All chromium samples were analyzed using EPA Method 200.8 within the holding period
of the preserved samples.
Fluoride
Samples were collected headspace free into polyethylene bottles provided by the
analytical laboratory, capped tightly and stored refrigerated. All fluoride samples were
analyzed using Standard Method 4500 FC within the holding period of the preserved
samples (28 days).
Vanadium
Samples were collected headspace free into polyethylene bottles provided by the
analytical laboratory, capped tightly and stored refrigerated. The sample bottles from the
35
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laboratory included the preservative (HNCb) for a holding period of up to six months.
All vanadium samples were analyzed using EPA Method 200.8 within the holding period
of the preserved samples.
Barium
Samples were collected headspace free into polyethylene bottles provided by the
analytical laboratory, capped tightly and stored refrigerated. The sample bottles from the
laboratory included the preservative (HNOs) for a holding period of up to six months.
All barium samples were analyzed using EPA Method 200.8 within the holding period of
the preserved samples.
Calcium
Samples were collected headspace free into polyethylene bottles provided by the
analytical laboratory, capped tightly and stored refrigerated. The sample bottles from the
laboratory included the preservative (HNOs) for a holding period of up to six months.
All calcium samples were analyzed using EPA Method 200.7 within the holding period
of the preserved samples.
SDI
Sample water was collected in a 5-gallon polyethylene cube-container, headspace free
and shipped overnight to the laboratory for analysis. The American Society of Testing
and Materials (ASTM) test number 4189-95 procedures were followed for the SDI
calculation.
Representativeness of Operational Parameters
As specified by NSF, representativeness for operational parameters entails collecting a
sufficient quantity of data during operation to be able to detect a change in operations.
As specified by NSF, detecting a ±10% change in an operating parameter, such as
pressure, is sufficient. Operational parameters including flow and pressure were recorded
twice per day, which NSF specifies as sufficient for tracking changes in operational
conditions that exceed this 10% range.
Flow Rates
The permeate and concentrate flow rates were verified daily using a calibrated container
and stopwatch method to manually verify the flow rates from the system. While no
adjustments to the panel mounted flow meters was possible, the manual "check" could
verify if the panel mounted flow meters were accurate.
3.12.4.2 Statistical Uncertainty
Statistical uncertainty of the water quality parameters analyzed were evaluated through
calculation of the 95% confidence interval around the sample mean for parameters with eight or
more samples. Description of the confidence interval calculation is provided in Section 3.12.5.
36
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3.12.4.3 Methodology for Measurement of Precision and Accuracy
Precision and Accuracy for Water Quality Parameters
Tables 3-7 and 3-8 summarize the methodology used in the ETV for the measurement of
precision and accuracy for each water quality analysis performed for the verification study.
Arsenic speciation columns were QA/QC checked by NSF and were provided by NSF for the
verification testing. The sampling location for each duplicate sample was alternated between the
feed water, permeate, and concentrate.
Precision and Accuracy for Operational Parameters
The operational parameters in the ETV included flow rates and pressures. Water flow rates were
verified for all flow meters (located on the permeate and concentrate lines) daily by using a
calibrated container and a stopwatch. The duration of the bucket tests were one minute or
longer, depending on the magnitude of the flow rate.
Spiked Samples
Spiked samples were utilized at MWH laboratory, as presented in Table 3-8. Spiked samples
were applicable for the analyses performed on-site at the treatment system at a 10% frequency,
as presented in Table 3-9.
Table 3-7: Methodology for Measurement of Precision and Accuracy
Parameter
Arsenic (Total)
(report to nearest 1
Mg/L)
pH
(report to nearest 0. 1
pH unit)
Silica
(report to nearest 0. 1
mg/L)
Fluoride
(report to nearest 0. 1
mg/L)
Chromium
(report to nearest 1
Mg/L)
Vanadium
(report to nearest 1
Mg/L)
TOC
(report to nearest 0.5
mg/L)
Chloride
(report to nearest 1
mg/L)
MRL
l.Ong/L
0-14pH
units
0.05 mg/L
0. 1 mg/L
2 Mg/L
10 pg/L
0.5 mg/L
1 mg/L
On-site Duplicate
Frequency
Seven measurements per
week in duplicate (33% of
samples)
Seven measurements per
week in duplicate (33% of
samples)
One sample per week in
duplicate (33% of samples)
One sample per week in
duplicate (33% of samples)
One sample per week in
duplicate (33% of samples)
One sample per week in
duplicate (33% of samples)
One sample per week in
duplicate (33% of samples)
One sample per week in
duplicate (33% of samples)
Acceptable
Precision
30%
10%2
30%
20%
30%
30%
30%
20%
Accuracy
See procedures of MWH
Laboratory (see Table 3-8)
Daily 3-point calibration
with certified pH buffers in
range of measurements
(4.0, 7.0 and 10.0)
See procedures of MWH
Laboratory
(see Table 3 -8)
See procedures of MWH
Laboratory
(see Table 3 -8)
See procedures of MWH
Laboratory
(see Table 3 -8)
See procedures of MWH
Laboratory
(see Table 3 -8)
See procedures of MWH
Laboratory
(see Table 3 -8)
See procedures of MWH
Laboratory
(see Table 3 -8)
37
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Table 3-7: Methodology for Measurement of Precision and Accuracy (continued)
Parameter
MRL
On-site Duplicate
Frequency
Acceptable
Precision
Accuracy
Iron
(report to nearest 0.5
mg/L)
Manganese
(report to nearest 0.5
mg/L)
Sulfate
(report to nearest 1
mg/L)
Temperature
(report to nearest
0.1°C)
Alkalinity
(report to nearest 1
mg/L as CaCO,)
Hardness
(report to nearest 1
mg/L as CaCO,)
Turbidity
(report to nearest
0.05 mg/L)
Conductivity
(report to nearest 0.1
l_imho/cm)
Barium
(report to nearest 0.5
mg/L)
Calcium
(report to nearest 0.5
mg/L)
TSS
(report to nearest 1
mg/L)
SDI
(report to nearest 1
mg/L)
TDS
(report to nearest 1
mg/L)
0.5 mg/L One sample per week in
duplicate (33% of samples)
0.015 mg/L One sample per week in
duplicate (33% of samples)
2 mg/L One sample per week in
duplicate (33% of samples)
NA Two measurements per
week in duplicate (20% of
samples)
10 mg/L One sample per week in
duplicate (33% of samples)
10 mg/L One sample per week in
duplicate (33% of samples)
0.05NTU One sample per week in
duplicate (33% of samples)
4 |imho/cm Eight samples per week in
duplicate (20% of samples)
2 (ig/L One sample per week in
duplicate (33% of samples)
1 mg/L One sample per week in
duplicate (33% of samples)
4 mg/L One sample per week in
duplicate (33% of samples)
1 One sample per month in
duplicate (100% of samples)
10 mg/L Four samples per week in
duplicate (20% of samples)
30% See procedures of MWH
Laboratory
(see Table 3-8)
30% See procedures of MWH
Laboratory
(see Table 3-8)
20% See procedures of MWH
Laboratory
(see Table 3-8)
10%3 Initial and weekly
verification against a NIST
thermometer.
30% Weekly calibration
verification using known
standards at two
concentration levels
30% Weekly calibration
verification using known
standards at two
concentration levels
30%3 Initial and weekly
calibration with primary
standards. Daily
calibration verification
with secondary standards.
10% Daily calibration
verification using known
standards at three
concentration levels
30% See procedures of MWH
Laboratory
(see Table 3-8)
30% See procedures of MWH
Laboratory
(see Table 3-8)
30% See procedures of MWH
Laboratory
(see Table 3 -8)
30% Use procedures of the
American Society of
Testing and Materials
(ASTM) test number
4189-95.
30% See procedures of MWH
Laboratory
(see Table 3-8)
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Table 3-7: Methodology for Measurement of Precision and Accuracy (continued)
Parameter
MRL
On-site Duplicate
Frequency
Acceptable
Precision
Accuracy
Chlorine
(report to nearest 0.1
mg/L)
0.02 mg/L Four samples per week in
duplicate (25% of samples)
30% Use Hach 8167 (total) and
Hach8021 (free)
procedures for accuracy
using Hach standard
solutions.
As and dissolved arsenic samples were prepared on-site using arsenic speciation procedures developed by
Battelle for the EPA (see Appendix B). The laboratory method used to measure the arsenic is EPA 200.8, and
will measure total arsenic (after on-site preparation).
"Daily" refers to each day the verification plant is staffed (7 days a week).
For all on-site duplicate analyses, the first analysis is considered the sample and that result is reported. The
duplicate analysis is used for calculating precision per Section 6.3.4 in Chapter 1 of the EPA/NSF ETVProtocol
for Equipment Verification Testing for Arsenic Removal (EPA/NSF, 2003).
Table 3-8: Laboratory Water Quality Analyses Indicators
Parameter
Arsenic
(Total)
TDS
TSS
Silica
Fluoride
Iron
Manganese
Sulfate
Chloride
Chromium
Vanadium
Barium
Calcium
TOC
Laboratory
Fortified
Matrix
(LFM),
i.e. spike
sample
10%
(1 per 10
samples)
10%
10%
10%
10%
10%
10%
10%
10%
10%
10%
10%
10%
10%
LFM
Duplicate
10%
10%
10%
10%
10%
10%
10%
10%
10%
10%
10%
10%
10%
10%
LFM
Acceptance
Limits
(%
Recovery)
+30
< 5% RPD
< 20% RPD
+30
+20
+30
+30
+20
+20
+30
+30
+30
+30
+10
Method
Blank
(MB)
5%
(1 per 20
samples or
less)
5%
5%
5%
5%
5%
5%
10%
10%
5%
5%
5%
5%
run after
each
sample
MB
Acceptance
Limits
< MRL1
< MRL1
< MRL1
< MRL1
< MRL1
< MRL1
< MRL1
-------
Table 3-9: On-Site Water Quality Analyses Indicators
Acceptable Accuracy
On-Site Parameters On-site Spike Frequency (% Recovery)
Alkalinity 10% + 30
Hardness 10% + 30
Chlorine 10% + 30
Turbidity NA1 NA1
pH NA1 NA1
Temperature NA NA
Conductivity NA1 NA1
Accuracy documented by proper instrument setup and calibration with buffers or standards.
Accuracy established by using a NIST traceable thermometer on a weekly basis.
Method Blanks
The methodology for use of method blanks is summarized in Table 3-10. Field blanks were
submitted with each set of samples submitted to MWH Laboratories. One field blank was
collected for each parameter submitted for analysis.
Table 3-10: Methodology for Use of Method Blanks
Method Methodology for Blanks
Arsenic Blanks were used in accordance with the procedures of MWH
Laboratory:.
pH Purchased certified pH buffers; no use of blanks.
Temperature No use of blanks.
Alkalinity Purchased reagent-grade ultra-pure water and kept in stock at the
verification plant for use as a blank on a weekly basis to verify proper
operation of the instrument.
Total Hardness Purchased reagent-grade ultra-pure water and kept in stock at the
verification plant for use as a blank on a weekly basis to verify proper
operation of the instrument.
Turbidity Purchased reagent-grade ultra-pure water and kept in stock at the
verification plant for use as a blank on a daily basis to verify proper
operation of the instrument.
Conductivity No use of blanks.
TDS Blanks were used in accordance with the procedures of MWH
Laboratory:.
Other Inorganics Blanks were used in accordance with the procedures of MWH
Laboratory'.
1 See Table 3-8.
Proficiency Testing Samples
Proficiency Testing (PT) samples were analyzed in accordance with the procedures of the MWH
Laboratory, which performed all laboratory analyses. External PT samples (single blind) were
analyzed approximately twice a year for each analysis for which National Environmental
Laboratory Accreditation Conference (NELAC) requires PT samples. Additionally, a laboratory
control sample (typically second source) is analyzed with each analytical batch.
40
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3.12.4.4 Completeness
Completeness refers to the number of valid, acceptable samples collected from a measurement
process compared to the number of samples expected to be obtained. The completeness
objective for data generated during this verification test is based on the number of samples
collected and analyzed for each parameter and/or method. Table 3-11 illustrates the
completeness objectives for performance parameter and/or method based on the sample
frequency:
Table 3-11: Completeness Objectives Based on Sample Frequency
Number of Samples Per Parameter
and/or Method Percent Completeness
(MO 80%
11-50 90%
>50 95%
3.12.5 Calculation of Indictors of Data Quality
Statistical Uncertainty
For the water quality parameters monitored, 95% confidence intervals were calculated for data
sets of eight values or more. The following equation was used for confidence interval
calculation:
Confidence Interval = x± [Vi,i -(a/2) x (SA/n)]
where: x = sample mean
S = sample standard deviation
n = number of independent measurements included in the data set
t = Student's t distribution value with n-1 degrees of freedom
a = significance level, defined for 95% confidence as: 1 - 0.95 = 0.05
According to the 95% confidence interval approach, the a term is defined to have the value of
0.05, thus simplifying the equation for the 95% confidence interval in the following manner:
95% Confidence Interval = x + [In-1,0.975 x (SA/n)]
Calculation of Precision
As specified in Standard Methods (Method 1030 C), precision is specified by the standard
deviation of the results of replicate analyses. The overall precision of a study includes the
random errors involved in sampling as well as the errors in sample preparation and analysis.
n
Precision = Standard Deviation = V[Z (x"z - x)2 -^ (n - 1)]
/=!
where: x = sample mean
X; = Ah data point in the data set
41
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n = number of data points in the data set
Precision refers to the degree of mutual agreement among individual measurements and provides
an estimate of random error. Analytical precision is a measure of how far an individual
measurement may be from the mean of replicate measurements. The standard deviation and
relative standard deviation recorded from sample analyses were recorded as a means to quantify
sample precision. The percent relative standard deviation was calculated in the verification study
in the following manner:
%Relative Standard Deviation = S(100)/Xaverage
where S = Standard Deviation
Xaverage= the arithmetic mean of the recovery values
Calculation of Accuracy
Accuracy is quantified as the percent recovery of a parameter in a sample to which a known
quantity of that parameter was added.
Accuracy = Percent Recovery = 100 x [1- (Xknown - X
where Xknown = known concentration of measured parameter
= measured concentration of parameter
Calculation of Completeness
Completeness is defined as the following for all measurements:
%C = (V/T)X100
where: %C = percent completeness
V = number of measurements judged valid
T = total number of measurements
3.12.6 Corrective Action Plan
The corrective action plan for water quality parameters is summarized in Table 3-12.
42
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Table 3-12: Corrective Action Plan
Parameter
Acceptance Criteria
Sequence of Steps for Corrective Action
Any Duplicate
Analysis
Any Method Blank
Any Performance
Evaluation (PE) or
Proficiency Sample
pH
Temperature
Turbidity
(Bench-top)
Alkalinity,
Total Hardness,
Calcium Hardness,
TDS
See Table 3-7
See Table 3-8; criteria set by
MWH Laboratory
Within recovery specified for
each PE or proficiency
sample
<1 0% difference from
previous day
<20% difference from
previous day
No increasing or decreasing
trend indicated by results of
proficiency samples
<20% difference from
previous reading
Re-sample duplicates
Check instrument calibration; re-calibrate
instrument
See Table 3-8; perform procedures specific to
each analysis as determined by MWH
Laboratory
Check and verify all steps in sample collection
and analysis
Re-do PE or proficiency sampling and analysis
Check for change in feed water source or supply
Check instrument calibration
Re-calibrate instrument
Check for change in feed water source or supply
Check/verify system operating conditions
Verify turbidimeter operation and status
sample tap
Perform routine maintenance/cleaning
instrument
Verify calibration using secondary standards
Re-calibrate using primary standards
Verify change in feed water source or supply
of
of
3.13 Operation and Maintenance
The following sections provide O&M criteria that were necessary for a safe and successful
operation of the M-15,000 RO Treatment System.
3.13.1 Operation
Start-Up Procedures
The start-up sequence, as provided by the manufacturer, for the M-15,000 RO Treatment System
is:
1. Ensure power switch (located on top of control box) is in the off position.
2. Plug the unit into an appropriate power supply.
3. If installing a pressure tank system, open the ball valve on the bulkhead.
4. Turn the blending valve to coldest setting [90°].
5. Fully open the concentrate needle valve by turning it counter clockwise.
6. Fully close recirculate needle valve by turning it clockwise.
7. Turn the incoming water supply on the RO processor to the "on" position.
The water inlet solenoid valve will open.
There is a 5-second delay before the pump starts.
43
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The system will cycle on and off automatically during initial start up as air is
purged from system.
Allow the unit to run for five minutes while excess air is being purged from
system.
8. Close the concentrate needle valve until the feed pressure gauge reaches a max. of 150
psig.
9. Open the recirculation needle valve until the unit feed pressure gauge drops to 140 psig.
10. Close the concentrate needle valve until 150 psig is again achieved on the pump feed
pressure gauge.
Shut Down Procedures
1. Turn incoming feed water off while unit is running.
2. System will automatically turn off due to lack of feed water pressure.
3. Turn power switch to the OFF position.
3.13.2 Maintenance
Quarterly maintenance for the Ml5,000 RO Treatment System requires replacement of the
cartridge sediment pre-filter and RO module O-rings.
Pre-filter Replacement Procedure
1. Turn incoming feed water off while unit is running.
2. System will automatically turn off due to lack of feed water pressure.
3. Turn power switch to the OFF position.
4. Close ball valve on permeate line connection on bulkhead
5. Unplug unit from power supply.
6. Place bucket under pre-filter to catch the water from the filter housing.
7. Using supplied filter wrench, loosen filter housing.
8. Replace with new 20-micron sediment filter and replace filter housing using wrench to
tighten securely, (o-rings and bowls need to be lubricated with a water-soluble lubricant
such as KY jelly).
9. Follow "start-up procedure".
Maintenance requires the replacement of the RO membrane modules based on efficiencies of
TDS reduction per module. To simulate this procedure, two of the six membranes were replaced
during the simulated maintenance procedures performed at the end of the testing period.
Module Replacement Procedure
1. Replace RO membrane by loosening retaining clamp at top of stainless steel membrane
vessel.
2. Carefully pry loose PVC end cap from stainless steel vessel.
3. Pull membrane from vessel using pliers if necessary and discard.
4. Take note of location of black BRINE SEAL located approximately 1/2" from one end of
membrane, so the new membrane is installed in the proper direction.
5. Lubricate O-Rings on both ends of the membrane and PVC vessel cap with KY Jelly or
other water-soluble lubricant. Vaseline or other petroleum-based lubricants will damage
rubber o-ring and cause leaks.
44
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6. Insert new membrane into vessel with the brine seal on same position as the old one just
removed. Replace PVC end cap and tighten clamp evenly.
7. Follow "start-up procedure".
3.13.3 Operability
During verification testing, attention was given to equipment operability aspects. Among the
factors that were considered were:
Fluctuation of flow rates and pressures through membrane unit the time interval at
which resetting is needed (i.e., how long can feed pumps hold on a set value for the feed
rate?)
Was there a device present to aid the operator with flow control adjustment?
Was a continuous particle counter provided for monitoring of membrane permeate?
Was a continuous conductivity meter provided for monitoring of membrane permeate?
Was transmembrane pressure measurement provided?
Was feed water recovery provided?
Was recycle flow rate provided?
Was rate of flow of raw water measured?
This report addresses the above questions. The issues of operability were dealt with in the
portion of the reports that are written in response to Tasks 1 & 2 of the verification testing plan
and may be found in Chapter 4.
45
-------
Chapter 4
Results and Discussion
4.1 Introduction
The verification testing of the M-15,000 RO Treatment System performed at the CVWD Well
7802 in Thermal, California, commenced on April 26, 2004, and concluded on May 26, 2004.
The system ran continuously with the exception of two brief system shut downs, and one
extended shut down period of approximately four days. The shut downs occurred on April 29,
May 3-6, and on May 13, 2004. In total, the system was in operation for 27 days.
Quarterly and a portion of annual (replacement of two RO membranes) O&M procedures were
performed after completion of the verification testing, on May 26, 2004. Results and discussion
of the membrane operation, cleaning efficiency (substituted by quarterly/annual O&M), finished
water quality, and data management are presented in this chapter as the following five tasks:
Task 1: Membrane Operation
Task 2: Cleaning Efficiency
Task 3: Feed water and Treated Water Quality Monitoring
Task 4: Data Handling Protocol
Task 5: Quality Assurance Project Plan (QAPP)
The field data (operational and water quality) was maintained in a field logbook per Section 3.11
(Task 4) and may be found in Appendix C. The corresponding off-site laboratory data may be
found in Appendix D.
4.2 Task 1: Membrane Operation
The objective of this task was to evaluate the M-15,000 RO Treatment System operation, not to
optimize the system. System performance was evaluated relative to the stated raw water quality
ranges specified by the manufacturer in Chapter 3 (Table 3-2). For verification testing purposes,
the equipment was operated for 27 days. During the testing period the membrane productivity,
rate of specific flux decline, and rejection capabilities were evaluated.
The objectives of Task 1 were to:
Evaluate the operational conditions for the membrane equipment relative to the stated
water quality goals,
Determine the feed water recovery achieved by the membrane equipment under the
operational conditions evaluated during the one month verification period, and
Determine the rate of specific flux decline observed over the testing period.
The following evaluation and reporting criteria for Task 1 enabled the objectives to be met:
General operational performance,
Power consumption,
46
-------
Consumables and waste generation, and
Concentrate stream characterization.
4.2.1 General Operational Performance
The purpose of this test was to evaluate the general operational performance of the M-15,000 RO
Treatment System. Operational information regarding this task was collected throughout the
length of the verification testing according to the frequency presented in Chapter 3 (see Table 3-
5). Specifically, the following operational parameters were monitored:
Feed water, permeate, concentrate, and recycle flow rates,
Membrane element inlet and feed water pressures,
Discharge tank pressure (permeate line) and back pressure (concentrate line),
Water recovery and recycle ratio,
Feed water temperature,
Specific flux (flux and temperature-corrected specific flux),
Net driving pressure, and
Osmotic pressure gradient.
4.2.1.1 Feed Water, Permeate, Concentrate, and Recycle Flow Rates
The M-15,000 RO Treatment System was equipped with panel mounted flow meters to read
permeate and concentrate flow rates and to make adjustments as necessary. The feed water flow
rate was recorded as the sum of the permeate and the concentrate flow rates. The recycle flow
rate was documented from a digital flow meter installed on the recycle line prior to the feed
water line. Each of these four flow streams (feed water, permeate, concentrate, and recycle - see
Figure 2-2 in Section 2.1) was monitored twice per day during the verification testing. This data
is graphically presented in Figure 4-1 with the corresponding data presented in Table 4-1.
Included in this table are the average, minimum, maximum, count, standard deviation, and 95%
confidence interval data calculated for each of the flow streams. Since there were two different
types of pre-filters used during the study (carbon bloc and sediment), Table 4-1 has been
subdivided into two sections, each representing the type of pre-filter used during the verification
test.
The vertical lines in Figure 4-1 represent each time the pre-filter was changed and the break in
the data represents the four days the system was down (May 3-6) due to operational issues. The
feed water flow rate between April 26, 2004 and May 13, 2004 continued to decrease. Steps to
recover the feed flow rate included changing out the carbon bloc pre-filter, which served to
temporarily improve the feed flow rate. Once it was discovered that the periodic operation of the
CVWD Well 7802 introduced a slug of solids with each start-up (approximately every three
days), the carbon bloc pre-filter was replaced with a sediment pre-filter on May 13, 2004. After
this modification to the system, a relatively constant feed flow rate (25 gpm on average) was
achieved. The initial decreasing feed water flow rates (approximately 20 gpm decreasing to 17
gpm with the carbon bloc pre-filter) led to varied flow rates in the concentrate, permeate and
recycle flows, which were also stabilized after replacing the carbon bloc pre-filter with a
sediment pre-filter. While the carbon bloc pre-filter was originally determined necessary due to
47
-------
the chlorine levels in the feed water, the operational issues caused by the pre-filter clogging led
the manufacturer to recommend the use a sediment pre-filter in place of the carbon bloc and risk
damage to the membranes due to exposure to chlorine for the remaining limited ETV operation
period. The system ran continuously for 27 of the 31-day verification testing period. For one
four-day period, the system was shut down due to operational issues. Clogging of the carbon
bloc pre-filter is believed to be the cause of the shut down. Ideally at this test sight, the vendor
has indicated that a separate granular activated carbon tank would be used to remove the chlorine
prior to the M-15,000 RO Treatment System. The pre-filter on the M-15,000 RO Treatment
System would then consist of a sediment filter to further reduce the amount of particulates prior
to the water entering the RO.
Carbon Block
Pre-Filter Changed
Carbon Block Pre-
Filter Replaced
with Sediment Pre
- Feed Water
Permeate
Recycled Water
Concentrate
o
jo
o
^H
-------
Table 4-1: Feed Water, Permeate, Concentrate and Recycle Flow Rates
Carbon Bloc
Pre-filter
Date
4/26/04
4/27/04
4/28/04
4/29/04
4/30/04
5/1/04
5/2/04
5/7/04
5/8/04
5/9/04
5/10/04
5/11/04
5/12/04
5/13/04 (before)
Average
Minimum
Maximum
Number of
C 1
Samples
Standard Dev.
95% Confidence
Interval
Sediment Pre-
fllter
5/13/04 (after)
5/14/04
5/15/04
5/16/04
5/17/04
5/18/04
5/19/04
5/20/04
5/21/04
5/22/04
5/23/04
5/24/04
5/25/04
5/26/04
Average
Minimum
Maximum
Number of
Samples
Standard Dev.
95% Confidence
Interval
AM
20.50
19.50
19.00
18.00
B2: 13.00
A2:1700
17.00
16.75
23.00
23.25
22.00
21.50
19.75
19.00
17.75
19.57
16.75
23.25
14
2.21
(18.08,
21.07)
25.50
25.25
25.00
25.50
26.00
26.50
25.00
25.00
25.00
24.50
24.50
24.50
25.00
24.75
25.14
24.50
26.50
14
0.58
(24.75,
25.53)
Feed Water
(gpm)1
PM
19.50
19.50
18.50
16.00
B: 16.50
A17.50
17.00
16.50
23.25
23.00
22.00
21.50
19.50
18.50
NA
19.40
16.00
25.25
13
2.41
(17.69,
21.12)
Feed Water
(gpm)
25.50
25.25
25.00
25.50
26.00
26.00
25.00
25.25
25.00
24.50
24.50
24.50
24.75
24.75
25.11
24.50
26.00
14
0.51
(24.76,
25.45)
Ave
20.00
19.50
18.75
17.00
AM 15.00
IM 17.00
17.00
16.63
23.13
23.13
22.00
21.50
19.63
18.75
17.75
19.43
16.63
23.13
14
2 27
(17.89,
20.96)
25.50
25.25
25.00
25.50
26.00
26.25
25.00
25.13
25.00
24.50
24.50
24.50
24.88
24.75
25.13
24.50
26.25
14
0.54
(24.76,
25.49)
AM
14.00
13.50
13.00
12.80
B:11.00
A: 9.50
8.50
8.25
11.50
11.50
11.00
10.75
10.00
9.50
9.25
10.93
8.25
14.00
14
1.87
(9.67,
12.20)
13.00
12.75
12.50
13.00
13.00
13.00
12.50
12.50
12.25
12.00
12.00
12.00
12.00
12.25
12.48
12.00
13.00
14
0.41
(12.20,
12.76)
Permeate
(gpm)
PM
13.50
13.50
12.50
14.00
B:9.00
A 9.00
8.50
8.25
11.50
11.25
11.00
10.75
10.00
9.50
NA
11.02
8.25
14.00
13
1.94
(9.64,
12.40)
Permeate
(gpm)
13.00
12.75
12.50
13.00
12.50
13.00
12.50
12.50
12.25
12.00
12.00
12.00
12.00
12.25
12.45
12.00
13.00
14
0.38
(12.19,
12.71)
Ave
13.75
13.50
12.75
13.40
AM 1025
IM9.00
8.50
8.25
11.50
11.38
11.00
10.75
10.00
9.50
9.25
10.91
8.25
13.75
14
1.88
(9.64,
12.19)
13.00
12.75
12.50
13.00
12.75
13.00
12.50
12.50
12.25
12.00
12.00
12.00
12.00
12.25
12.46
12.00
13.00
14
0.39
(12.20,
12.73)
Concentrate
(gpm)
AM PM
6.50 6.00
6.00 6.00
6.00 6.00
5.20 2.00
B:2.00 B:7.50
A: 8.50 A 8.50
8.50 8.50
8.50 8.25
11.50 11.75
11.75 11.75
11.00 11.00
10.75 10.75
9.75 9.50
9.50 9.00
8.50 NA
8.71 8.38
5.20 2.00
11.75 11.75
14 13
2.15 2.81
(7.25, (6.39,
10.17) 10.38)
Ave
6.25
6.00
6.00
3.60
AM 525
IM8.00
8.50
8.38
11.63
11.75
11.00
10.75
9.63
9.25
8.50
8.55
3.60
11.75
14
2.40
(6.93,
10.18)
Concentrate
(gpm)
12.50 12.50
12.50 12.50
12.50 12.50
12.50 12.50
13.00 13.50
13.50 13.00
12.50 12.50
12.50 12.75
12.75 12.75
12.50 12.50
12.50 12.50
12.50 12.50
13.00 12.75
12.50 12.50
12.66 12.66
12.50 12.50
13.50 13.50
14 14
0.30 0.29
(12.45, (12.47,
12.87) 12.86)
12.50
12.50
12.50
12.50
13.25
13.25
12.50
12.63
12.75
12.50
12.50
12.50
12.88
12.50
12.66
12.50
13.25
14
0.27
(12.47,
12.85)
AM
8.53
9.00
9.14
10.16
B: 12.84
A 8.90
9.65
9.84
6.30
6.94
7.80
8.05
9.42
9.70
10.68
8.87
6.30
10.68
14
1.24
(8.03,
9.70)
5.27
5.75
5.35
5.19
4.88
4.58
5.24
5.38
5.37
5.48
5.30
5.39
5.16
5.36
5.26
4.58
5.75
14
0.27
(5.08,
5.45)
Recycle
(gpm)
PM
8.85
9.07
8.34
11.96
B: 9.91
A 9.56
9.72
9.89
6.76
6.95
7.89
8.06
9.43
9.85
NA
8.95
6.76
11.96
13
1.39
(7.96,
9.93)
Recycle
(gpm)
5.31
5.81
5.37
5.21
4.62
5.14
5.27
5.19
5.45
5.48
5.29
5.46
5.21
5.34
5.30
4.62
5.81
14
0.26
(5.12,
5.47)
Ave
8.69
9.04
8.74
11.06
AM 10X7
IM9.74
9.69
9.87
6.53
6.95
7.85
8.06
9.43
9.78
10.68
8.97
6.53
11.06
14
1.30
(8.09,
9.85)
5.29
5.78
5.36
5.20
4.75
4.86
5.26
5.29
5.41
5.48
5.30
5.43
5.19
5.35
5.28
4.75
5.78
14
0.25
(5.11,
5.45)
Feed water flow rates are calculated values and are the sum of the permeate and concentrate flow rates.
2 B= Before and A= After manual adjustments made to system.
Note: Only the 'after' values and averages on April 30,2004 are used in the statistical calculations.
AM = First sample daily collection.
PM = Second sample daily collection.
NA = Not Applicable.
49
-------
4.2.1.2 Membrane Element Inlet and Feed Water Pressures
Pressure gauges were panel mounted for the inlet (feed water plus recycled water) pressure, back
pressure (pressure on the concentrate line), and tank pressure (pressure on the permeate line
which was open to drain for the purpose of this testing). The feed water pressure gauge was
installed on the feed water line between the raw (chlorinated groundwater) line and the inlet to
the M-15,000 RO Treatment System. Pressure was monitored and recorded twice daily
[morning (AM) and evening (PM)], with the average daily (AM and PM) data presented in
Figure 4-2 and the corresponding data presented in Table 4-2. Additionally, Table 4-2 presents
the pressure data as two data sets, with the carbon bloc pre-filter and with the sediment pre-filter,
to evaluate the operational impact (with regard to pressure) of using different types of pre-filters.
Throughout the verification test, there was a limited amount of variability in the feed water
pressure, ranging from 78 to 85 psi. There was, however, a larger range of pressure readings on
the inlet pressure (ranging from 102 to 150 psi), believed to be related to clogging of the carbon-
bloc pre-filter (discussed in additional detail in Section 4.2.1.1). While the carbon bloc pre-filter
was in place, the inlet pressure ranged from 102 to 147 psi. Once the sediment pre-filter
replaced the carbon bloc pre-filter, the inlet pressure ranged from 140 to 150 psi.
In addition to monitoring the feed water and inlet pressures, the back pressure (concentrate line)
and the tank pressure (permeate line) were monitored twice daily for use in calculating the daily
net driving pressure. During the verification test, both the permeate and concentrate lines
discharged to a drain under atmospheric conditions. The recorded back pressures ranged from
18 to 75 psi, and the tank pressures ranged from 0 to 7 psi. There was large variability in the
back pressure while the carbon bloc pre-filter was in use (i.e. prior to May 13, 2004) with a
steady back pressure realized once the sediment pre-filter was in use.
50
-------
160
Carbon Block
Pre-Filter Changed
D-D-Ovcr^^D-H^c^^
Carbon Block Pre-Filter
Replaced with Sediment
Pre-Filter
-O- Inlet Water
Feed Water
O Permeate
Concentrate
Verification Testing Date
Figure 4-2: Average daily feed water, inlet, back pressure, and tank pressures.
51
-------
Table 4-2:
Carbon
Bloc Pre-
fllter
Date
4/26/04
4/27/04
4/28/04
4/29/04
4/30/04
5/1/04
5/2/04
5/7/04
5/8/04
5/9/04
5/10/04
5/11/04
5/12/04
5/13/04
(before)
Average
Minimum
Maximum
Number of
Samples
Standard
Deviation
95%
Confidence
Interval
Sediment
Pre-filter
5/13/04
(after)
5/14/04
5/15/04
5/16/04
5/17/04
5/18/04
5/19/04
5/20/04
5/21/04
5/22/04
5/23/04
5/24/04
5/25/04
5/26/04
Average
Minimum
Maximum
Number of
Samples
Stand. Dev.
95%
Confidence
Interval
Feed Water, Inlet, Back Pressure, and Tank Pressures
Feed Water Inlet Back Pressure,
Pressure (psi) Pressure (psi) Concentrate Line psi)
AM
85
82
80
84
B':85
A1: 82
85
84
82
80
84
85
85
85
85
83
80
85
14
2
(82,
85)
PM
82
82
82
85
B: 85
A: 85
85
85
80
80
82
84
85
85
NA
83
80
85
13
2
(82,
85)
Ave
84
82
81
85
AM: 84
PM:85
85
85
81
80
83
85
85
85
85
83
80
85
14
2
(82, 85)
AM
145
145
135
125
B: 148
A: 125
105
105
115
135
125
125
115
110
102
122
102
145
14
14
(113,
132)
Feed Water
Pressure
78
80
78
78
82
78
78
78
78
80
78
80
82
80
79
78
82
14
2
(78,
80)
80
80
78
80
82
80
78
82
78
80
78
80
80
80
80
78
82
14
1
(79,
81)
(psi)
79
80
78
79
82
79
78
80
78
80
78
80
81
80
79
78
82
14
1
(79, 80)
PM
145
145
140
144
B110
Ave
145
145
138
135
AM: 137
A: 105 PM: 108
105
102
135
135
125
122
110
110
NA
125
102
145
13
17
(113,
137)
Inlet
Pressure
147
147
147
147
147
140
147
147
148
148
147
149
150
149
147
140
150
14
2
(146,149)
147
147
147
142
147
147
147
149
147
147
148
148
150
149
147
142
150
14
2
(146,
149)
105
104
125
135
125
124
113
110
102
123
102
145
14
15
(113,
133)
AM
65
70
70
75
B:90
A: 50
20
20
45
55
50
50
40
30
20
47
20
75
14
19
(34, 60)
PM
65
70
70
75
B: 35
A: 20
20
18
55
55
50
50
35
25
NA
47
18
75
13
21
(32,
62)
Ave
65
70
70
75
AM: 70
PM:28
20
19
50
55
50
50
38
28
20
46
19
75
14
20
(33,
59)
Back Pressure,
(psi)
147
147
147
145
147
144
147
148
148
148
148
149
150
149
147
144
150
14
2
(146, 148)
Concentrate Line psi)
65
65
65
65
65
65
68
68
68
65
65
70
70
68
67
65
70
14
2
(65, 68)
65
65
65
65
60
65
65
69
65
65
65
70
65
65
65
60
70
14
2
(64,
67)
65
65
65
65
63
65
67
69
67
65
65
70
68
67
66
63
70
14
2
(65,
67)
Tank Pressure,
Permeate Line (psi)
AM PM
4 4
2 2
2 2
4 4
B:2 B:0
A: 0 A: 0
0 0
0 0
2 0
0 0
0 0
0 0
0 0
0 0
0 NA
1 1
0 0
4 4
14 13
2 2
(0,2) (0,2)
Ave
4
2
2
4
AM: 1
PM:0
0
0
1
0
0
0
0
0
0
1
0
4
14
1
(0,2)
Tank Pressure,
Permeate Line
2 0
0.0 0
0.0 0
0.0 0
0.0 0
5.0 0
5.0 0
5.0 0
5.0 0
5.0 0
5.0 0
5.0 5
5.0 0
7.0 4
4 1
0 0
7 5
14 14
3 2
(2,5) (0,2)
(psi)
1
0
0
0
0
3
3
3
3
3
3
5
3
6
2
0
6
14
2
0,3)
B= Before and A= After manual adjustments made to system.
Note: Only the 'after' values and averages on April 30,2004 are used in the statistical calculations.
NA = Not Applicable.
AM = First sample daily collection.
PM = Second sample daily collection.
52
-------
4.2.1.3 Water Recovery and Recycle Ratio
The temporal profile of the percent water recovery over the verification testing period is
presented in Figure 4-3. The range of water recovery experienced during the verification testing
was 48% to 88% with an average of 53%. The manufacturer selected this range of water
recovery after examination of the initial operating data. Higher recovery rates occurred from
April 26, 2004 to April 29, 2004, until the time the unit shut down for the first time. Per the
manufacturers recommendations, the flow rates were adjusted, thus effecting the percent
recoveries. The data from April 30, 2004 through May 26, 2004 indicates a relatively constant
system recovery.
80-
«
60-
40-
20-
i
!
p
f
!{+--
»if
i
i ?N
j *
-------
presented in Table 4-3 indicates that both the percent water recovery and the recycle ratio (both
influences by system flow rates) are influenced by the type of pre-filter used with the M-15,000
RO Treatment System.
Table 4-3: Water Recovery
Carbon Bloc Pre-
fllter
Date
4/26/04
4/27/04
4/28/04
4/29/04
4/30/04
5/1/04
5/2/04
5/7/04
5/8/04
5/9/04
5/10/04
5/11/04
5/12/04
5/13/04 (before)
Average
Minimum
Maximum
Number of
Samples
Standard Dev.
95% Confidence
Interval
Sediment
Pre-filter
5/1 3/04 (after)
5/14/04
5/15/04
5/16/04
5/17/04
5/18/04
5/19/04
5/20/04
5/21/04
5/22/04
5/23/04
5/24/04
5/25/04
5/26/04
Average
Minimum
Maximum
Number of
Samples
Standard Dev.
95% Confidence
Interval
AM
68
69
68
71
B1: 85
A1: 56
50
49
56
49
50
50
51
50
52
56
49
71
14
9
(51,62)
51
50
50
51
50
49
50
50
49
49
49
49
48
49
50
48
51
14
1
(49, 50)
and Recycle
Water
Recovery (%)
PM
69
69
68
88
B: 55
A: 51
50
50
49
49
50
50
51
51
NA
57
49
88
13
12
(49, 66)
Water
Recovery (%)
51
50
50
51
48
50
50
50
49
49
49
49
48
49
50
48
51
14
1
(49, 50)
Ratio
Ave
69
69
68
79
AM: 71
PM:53
50
50
53
49
50
50
51
51
52
57
49
79
14
10
(50, 63)
51
50
50
51
49
50
50
50
49
49
49
49
48
49
50
48
51
14
1
(49, 50)
AM
0.29
0.32
0.32
0.36
B:0.50
A:0.34
0.36
0.37
0.24
0.23
0.26
0.27
0.32
0.34
0.38
0.32
0.23
0.38
14
0.05
(0.28,0.35)
0.17
0.19
0.18
0.17
0.16
0.15
0.17
0.18
0.18
0.18
0.18
0.18
0.17
0.18
0.17
0.15
0.19
14
0.01
(0.17,0.18)
Recycle
Ratio
PM
0.31
0.32
0.31
0.43
B:0.38
A:0.35
0.36
0.37
0.23
0.23
0.26
0.27
0.33
0.35
NA
0.32
0.23
0.43
13
0.06
(0.28, 0.36)
Recycle
Ratio
0.17
0.19
0.18
0.17
0.15
0.17
0.17
0.17
0.18
0.18
0.18
0.18
0.17
0.18
0.17
0.15
0.19
14
0.01
(0.17,0.18)
Ave
0.30
0.32
0.32
0.39
AM:0.42
PM:0.37
0.36
0.37
0.23
0.23
0.26
0.27
0.32
0.34
0.38
0.32
0.23
0.39
14
0.05
(0.28,0.35)
0.17
0.19
0.18
0.17
0.15
0.16
0.17
0.17
0.18
0.18
0.18
0.18
0.17
0.18
0.17
0.15
0.19
14
0.01
(0.17,0.18)
B= Before and A= After manual adjustments made to
Note: Only the 'after' values and averages on April 30,
NA = Not Applicable
AM = First sample daily collection
PM = Second sample daily collection
system.
2004 are used in the statistical calculations.
54
-------
4.2.1.4 Feed Water Temperature
Feed water temperature measurements were made twice daily using a NIST thermometer.
Temperatures were taken with each set of morning and evening analyses and ranged from 25.0°C
to 29.0°C with the morning samples and 27.0°C to 30.5°C with the evening samples (see Table
4-4). The feed water temperature variance was taken into consideration when calculating the
temperature adjusted flux values presented in the following section, Section 4.2.1.5 Specific
Flux.
Table 4-4: Feed Water
Date
4/26/04
4/27/04
4/28/04
4/29/04
4/30/04
5/1/04
5/2/04
5/7/04
5/8/04
5/9/04
5/10/04
5/1 1/04
5/12/04
5/13/04
5/14/04
5/15/04
5/16/04
5/17/04
5/18/04
5/19/04
5/20/04
5/21/04
5/22/04
5/23/04
5/24/04
5/25/04
5/26/04
Average
Minimum
Maximum
Number of Samples
Standard Deviation
Temperature
AM
29.0
26.5
25.0
27.0
26.0
27.0
26.5
26.0
26.0
27.5
27.0
27.0
26.5
27.0
27.5
28.0
28.0
27.0
27.0
27.0
26.0
27.0
27.5
26.5
27.0
26.0
27.0
26.9
25.0
29.0
27
0.8
95% Confidence Interval (26.5, 27.2)
Temperature (°C)
PM
28.5
30.5
30.5
27.5
27.5
27.5
27.5
27.5
27.0
28.0
28.0
28.5
28.5
28.5
28.5
27.5
28.5
28.0
28.5
28.0
28.0
28.0
28.0
27.5
27.5
27.5
28.0
28.1
27.0
30.5
27
0.8
(27.7, 28.5)
Daily Average
28.8
28.5
27.8
27.3
26.8
27.3
27.0
26.8
26.5
27.8
27.5
27.8
27.5
27.8
28.0
27.8
28.3
27.5
27.8
27.5
27.0
27.5
27.8
27.0
27.3
26.8
27.5
27.5
26.5
28.8
27
0.5
(27.2, 27.7)
AM = First sample daily collection.
PM = Second sample daily collection.
55
-------
4.2.1.5 Flux, Specific Flux, Net Driving Pressure, and Osmotic Pressure
Flux is a method of expressing permeate flow through the membranes. The flux was monitored
and recorded daily throughout the verification testing period, and the data is graphically
presented in Figure 4-4 with the corresponding data presented in Table 4-5. There are noticeable
declines in the flux, just prior to changing out the carbon bloc pre-filter. While the carbon bloc
pre-filter was in place, the flux ranged from 24 to 41 gfd, with an average of 32 gfd, standard
deviation of 5 gfd, and a 95% confidence interval of 28 to 36 gfd. Once the sediment pre-filter
was put on-line, the flux stabilized with an average 37 gfd, a range of 35 to 28, a standard
deviation of 1 gfd, and a 95% confidence interval of 36 to 37 gfd.
50
40 :
20 -
10 -
Carbon Block
Pre-Filter Changed
Carbon Block Pre-Filter Replaced
with Sediment Pre-Filter
JN
Tp
O
^5
JN
Ti
JN
ir>
Verification Testing Date
Figure 4-4 Temporal plot of flux verses time.
56
-------
Table 4-5: Daily Flux Data
Flux (gfd) Flux (gfd)
Date with Carbon Bloc Pre-filter Date with Sediment Pre-filter
4/26/04
4/27/04
4/28/04
4/29/04
4/30/04
5/1/04
5/2/04
5/7/04
5/8/04
5/9/04
5/10/04
5/11/04
5/12/04
5/13/04
Average
Minimum
Maximum
Number of Samples
Standard Deviation
95% Confidence
Interval
41
40
38
37
28
25
24
34
34
32
31
29
28
27
32
24
41
14
5
(28, 36)
5/13/04
5/14/04
5/15/04
5/16/04
5/17/04
5/18/04
5/19/04
5/20/04
5/21/04
5/22/04
5/23/04
5/24/04
5/25/04
5/26/04
Average
Minimum
Maximum
Number of Samples
Standard Deviation
95% Confidence
Interval
38
37
37
38
38
38
37
37
36
35
35
35
35
36
37
35
38
14
1
(36, 37)
Specific flux is used as an indicator of general operational performance. Specific Flux is
calculated by flux at a constant temperature (in this case, normalized to 25°C) divided by the net
driving pressure. Normalizing the flux to a constant temperature helps to account for the effects
of viscosity of water at varying temperatures on the permeate flow through the membranes. The
osmotic pressure data was calculated using daily TDS data and the pressures recorded during the
verification testing.
The specific flux normalized to 25°C (Equation 3.5) verses time over the verification testing
period is presented in Figure 4-5 and Table 4-6. In Table 4-6, the specific flux is presented as
two data sets: with the carbon bloc pre-filter and the sediment pre-filter. The specific flux while
using the carbon bloc pre-filter ranged from 0.32 gfd/psi to 0.44 gfd/psi, a 27% difference during
the 14-days of operation. The specific flux ranged from 0.32 gfd/psi to 0.38 gfd/psi, a 16%
difference, while the sediment pre-filter was utilized. The modules were to be replaced if a 20%
decline in the specific flux was detected. However, since the study began at a specific flux of 38
gfd, the manufacturer was confident the testing should continue without replacing the modules.
Initial decreases in the specific flux may be attributed to the aggressive operational parameters.
Once the system was stabilized by replacing the carbon bloc pre-filter with a sediment pre-filter,
a steady specific flux was achieved.
57
-------
0.50
0.45
a.
I
U
o
u
'0
at
a.
0.40
0.35 -
0.30
Carbon Block
Pre-Filter Chansed
Carbon Block Pre-
Filter Replaced with
Sediment Pre-Filter
-------
The osmotic pressure gradient is the difference in osmotic pressure generated across the
membrane barrier as a result of different concentrations of dissolved salts. IDS concentrations
were used as the constituent to calculate the daily osmotic pressure gradient from the verification
testing (see Equation 3-4). This data is graphically presented in Figure 4-6 with the
corresponding data shown in Table 4-7. The range of osmotic pressure while the carbon bloc
pre-filter was in use was 1.7 to 4.5 psi. When the carbon bloc pre-filter was replaced by the
sediment pre-filter, the range of osmotic pressure was 1.3 to 1.8 psi.
5.0 -r
Carbon Block
Pre-Filter Changed
Carbon Block Pre-Filter
Replaced with Sediment
Pre-Filter
o
oo
o
3-
o
l>
o
CN
CN
ft
Verification Testing Date
Figure 4-6: Osmotic pressure gradient verses time.
59
-------
Table 4-7: Os motic Pressure Gradient
Date
Osmotic
Pressure (psi)
with Carbon Bloc Pre-filter
Date
Osmotic
Pressure (psi)
with Sediment Pre-filter
4/26/04
4/27/04
4/28/04
4/29/04
4/30/04
5/1/04
5/2/04
5/7/04
5/8/04
5/9/04
5/10/04
5/11/04
5/12/04
5/13/04
Average
Minimum
Maximum
Number of
Samples
Standard
Deviation
95% Confidence
Interval
2.5
2.6
2.6
4.5
1.9
2.0
1.9
1.8
1.9
1.9
1.8
1.9
1.8
1.7
2.2
1.7
4.5
14
0.7
(1.7,2.7)
5/14/04
5/15/04
5/16/04
5/17/04
5/18/04
5/19/04
5/20/04
5/21/04
5/22/04
5/23/04
5/24/04
5/25/04
5/26/04
Average
Minimum
Maximum
Number of
Samples
Standard
Deviation
95% Confidence
Interval
1.8
1.8
1.7
1.6
1.6
1.6
1.7
1.5
1.4
1.4
1.5
1.3
1.5
1.6
1.3
1.8
13
0.2
(1.5,1.7)
Net driving pressure was calculated daily from the recorded feed water and concentrate streams
pressure, and is the average of the feed water and concentrate pressure readings minus the
permeate pressure and the osmotic pressure (see Equation 3-3). The net driving pressure during
the verification testing period is graphically presented in Figure 4-7 with the corresponding data
provided in Table 4-8. As with other operating parameters, there was a noticeable difference in
the net driving pressure while the carbon bloc pre-filter was in use, and what appears to be
stabilization of the net driving pressure once the sediment pre-filter was installed. The average
net driving pressure with the carbon bloc filter was 83 psi, compared to 102 psi with the
sediment pre-filter. Additionally, the standard deviation of the net driving pressure while the
carbon bloc pre-filter was in use was 14 psi, and was 2 psi while the sediment pre-filter was in
use.
60
-------
on
a.
1
Wl
Si
a.
G
"£
Z
Carbon Block
Pre-Filter Changed
40
Carbon Block Pre-Filter
Replaced with Sediment Pre-
o
oo
o
^F
o
(N
CO
(N
(N
Verification Testing Date
Figure 4-7: Temporal profile of net driving pressure.
61
-------
Table 4-8: Net Driving Pressure
Date
Net Driving Pressure (psi)
with Carbon Bloc Pre-filter
Date
Net Driving Pressure (psi)
with Sediment Pre-filter
4/26/04
4/27/04
4/28/04
4/29/04
4/30/04
5/1/04
5/2/04
5/7/04
5/8/04
5/9/04
5/10/04
5/11/04
5/12/04
5/13/04
Average
Minimum
Maximum
Number of
Samples
Standard Deviation
95% Confidence
Interval
99
103
98
92
86
61
61
76
93
86
86
76
68
59
82
59
103
14
15
(71, 92)
5/14/04
5/15/04
5/16/04
5/17/04
5/18/04
5/19/04
5/20/04
5/21/04
5/22/04
5/23/04
5/24/04
5/25/04
5/26/04
Average
Minimum
Maximum
Number of
Samples
Standard Deviation
95% Confidence
Interval
104
104
104
104
96
101
101
101
100
100
103
104
100
102
96
104
13
o
3
(100, 104)
4.2.2 Power Consumption
The M-15,000 RO Treatment System required 220 volts/11.5 amperage. The power
consumption in kilowatt-hours (KWH) to the system was 33 KWHs (on average) per day in
operation. The power consumption was monitored and recorded daily, as presented in Table 4-9.
The total power consumed for the 27 days of operation was 880 KWHs. The cost of electricity
was the primary consumable O&M cost for operating the system.
62
-------
Table 4-9: Power Totalizer for M-15,000 RO Treatment System
Date
4/26/04
4/27/04
4/28/04
4/29/04
4/30/04
5/1/04
5/2/04
5/7/04
5/8/04
5/9/04
5/10/04
5/11/04
5/12/04
5/13/04
5/14/04
5/15/04
5/16/04
5/17/04
5/18/04
5/19/04
5/20/04
5/21/04
5/22/04
5/23/04
5/24/04
5/25/04
5/26/04
Cumulative Power Totalizer Reading (KWH)
0
26
61
96
128
165
197
231
253
288
320
357
392
428
464
494
533
564
602
634
670
702
745
772
811
845
880
4.2.3 Consumables and Waste Generation
There were no "consumable" chemical items used for the verification testing; however, the pre-
filter to the system would be a consumable product and additional solid waste for disposal. The
concentrate waste stream produced from the verification test was blended back with the permeate
water for an equivalent water quality to the feed water from the CVWD Well 7802. This water
was then sent to a blow-off structure for disposal. The estimated concentrate production rate was
17,300 gallons per day, based on the targeted 50% recovery. The concentrate stream water
quality characteristics are discussed in additional detail in Section 4.4 (Task 3).
4.3 Task 2: Cleaning Efficiency
The objective of this task was to evaluate the efficiency of the membrane cleaning procedures
recommended by the manufacturer. The manufacturer proposes replacement of RO membranes
based on efficiencies of TDS reduction per module and quarterly maintenance procedures, which
involve replacement of pre-filters and RO module O-rings, in lieu of a cleaning procedure. While
not part of the quarterly maintenance procedures, two of the membranes (membrane number 5
and 6) were also replaced during the maintenance procedures to simulate a portion of annual
maintenance procedures.
63
-------
The total time to complete the O&M procedures was approximately 45 minutes. Visual
inspection of the pre-filter and the membranes showed signs of red discoloration, assumed to be
iron, sediment, and/or other suspended solids filtered out or precipitated onto the membranes.
As previously discussed in Chapter 3, prior to the system being manually shut down for the
O&M procedures, the unit automatically shut down on two prior occasions. It was believed that
the booster pump was being starved of water due to solids accumulation on the carbon bloc pre-
filter. Photograph 4 shows the three pre-filters used in the verification study. The first two are
carbon bloc pre-filters and the third filter is a pleated, sediment pre-filter.
Photograph 4: Watts Premier M-15,000 RO Treatment System Pre-filters
Photograph 5 shows the condition of the RO membranes once removed from the system during
the O&M procedures performed after the verification testing. There appeared to be "red"
discoloration and the presence of solids on the surface of the membranes, similar to those seen
on the pre-filters.
64
-------
Photograph 5: Membrane RO Number 6 - Post Verification Testing
4.3.1 Measure of Membrane Performance Post Quarterly O&M Procedures
After completion of the O&M procedures, the M-15,000 RO Treatment System was placed back
on line to determine the effect of the O&M procedures on the model performance. Table 4-10
lists the specific flux recoveries and Table 4-11 list the maintenance efficiency indictors
(performance indictors) prior to and after the O&M procedures. In Table 4-11, the percent
recovery of specific flux was calculated using Equation 3.14, expressed as the ratio between the
final specific flux (prior to the O&M procedures) and the initial specific flux (post O&M
procedures). There was little deviation between the specific flux prior to and after the O&M
procedures, with a percent recovery of 97%.
65
-------
Table 4-10: Pre-and Post-Maintenance Specific Flux Recoveries
Flux at Beginning of
Verification Study (4/26/04)
Flux Immediately Prior to
Quarterly O&M Procedures (5/26/04)
Flux After
Quarterly O&M Procedures (5/26/04)
Specific
Flux (gfd/psi)
0.38
0.34
0.33
% Recovery of
Specific
Flux (%)
97%
% Loss of Original
Specific
Flux (%)
13%
Table 4-11 Maintenance Efficiency Indicators
Flow Rate Prior to O&M Procedures, gpm
Flow Rate After O&M Procedures, gpm
Pressure Prior to O&M Procedures, psi
Pressure After to O&M Procedures, psi
Recovery Prior to O&M Procedures, psi
Recovery After to O&M Procedures, psi
Recycle Ratio Prior to O&M Procedures, psi
Recycle Ratio After to O&M Procedures, psi
Osmotic Pressure Prior to O&M Procedures, psi
Osmotic Pressure After to O&M Procedures, psi
Net Driving Pressure Prior to O&M Procedures, psi
Net Driving Pressure After O&M Procedures, psi
Temperature Prior to O&M Procedures, C
Temperature After to O&M Procedures, C
Feed Permeate Concentrate
Water
24.75 12.25 12.50
25.00 12.50 12.50
80 7 68
78 2 65
49
50
0.18
0.17
1.5
1.5
100
102
28.0
28.0
Recycle Inlet
5.34
5.28
149
147
--
--
-
-
--
A set of water samples for water quality analysis was collected just prior to and after the O&M
procedure. This data is presented in Table 4-12. From this table it appears that there is very
little difference between the before and after O&M procedure water quality.
66
-------
Table 4-12: Pre and Post O&M Feed Water, Permeate, and Concentrate Water Quality
Pre O&M May 24,
Parameter
Total Arsenic
Dissolved
Arsenic
As (III)
As(V)1
TOC
Calcium
Chloride
Hardness
Alkalinity
Free Chlorine
Total
Chlorine
pH
Turbidity
Conductivity
TDS
TSS
Manganese
Iron
Barium
Silica
Fluoride
Sulfate
Chromium
Vanadium
Units
Mg/L
Mg/L
Mg/L
Mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
-
NTU
umoh/cm
mg/L
mg/L
Mg/L
mg/L
Mg/L
mg/L
mg/L
mg/L
Mg/L
Mg/L
Feed Water
14
14
14
< 1.0
0.50
4.7
8.2
4
84
0.21
0.22
9.23
0.25
225
150
< 10
<2.0
0.023
7.3
14
0.78
19
13
51
Permeate
< 1.0
1.1
< 1.0
< 1.0
0.50
< 1.0
2.1
0
34
0.20
0.18
9.48
0.10
63.2
45
< 10
<2.0
< 0.010
<2.0
11
0.29
<2.0
< 1.0
5.3
2004
Concentrate
25
23
30
< 1.0
0.50
8.4
15
18
136
NA
NA
9.12
0.25
368
230
< 10
<2.0
0.023
12
17
1.2
38
23
88
Post
Feed Water
15
16
< 1.0
15
<0.50
4.7
8.7
4
82
0.35
0.35
9.17
0.20
231
140
< 10
<2.0
0.039
7.2
14
0.80
21
13
51
O&M May
Permeate
< 1.0
1.0
< 1.0
< 1.0
<0.50
< 1.0
1.7
0
26
0.32
0.33
9.41
0.10
52.6
34
< 10
<2.0
< 0.010
<203
8.2
0.24
<2.0
< 1.0
5.1
26, 2004
Concentrate
30
33
< 1.0
32
<0.50
8.7
15
10
132
NA
NA
9.10
0.40
387
230
< 10
<2.0
0.043
13
19
1.3
40
24
90
1 As (V) is a calculated value.
Conductivity
was measured twice per day.
3 Note: EPA Method 200.7
This value is
was used for this one analysis
the average of all the conductivity results.
withaMRLof20ng/L.
NA = Not applicable.
4.3.2 Review of Watts Premier Operation and Maintenance Manual
The Watts Premier O&M manual was previous discussed in Section 3.13. These procedures
were followed on May 26, 2004, upon completion of the verification study to simulate the
quarterly and a portion of the annual maintenance procedures. The O&M manual was very clear
and the maintenance procedure was completed in approximately 45 minutes. Upon completion
of the O&M procedures, the system was started back up and water quality data and operation
data was collected for comparison with the first startup of the equipment on April 26, 2004. As
with the maintenance procedures, the startup procedures were very clear and easy to follow as
well.
4.4 Task 3: Feed Water And Treated Water Quality Monitoring
The objective of this task was to evaluate the quality of water produced by the membrane system
and the removal of inorganic chemical contaminants achieved by the membrane system at the
67
-------
specified operational conditions. Monitoring of the water quality parameters included the
following: arsenic (total, As+3, and dissolved), pH, temperature, chloride, calcium, barium,
hardness, conductivity, chlorine (total and free), TDS, alkalinity, LSI, turbidity, TSS, silica,
fluoride, iron, manganese, sulfate, chromium, vanadium, TOC and SDL Water quality produced
was evaluated in relation to feed water quality and operational conditions. The verification study
indicated that arsenic can be removed by the M-15,000 RO Treatment System, but depending on
the source water characteristics, the appropriate pre-filter selection is important to prevent
clogging of the pre-filters.
In Figure 4-8, Temporal Plot of Total Arsenic, all permeate values were non-detect (ND) with a
MRL of 1.0 |ig/L, except on May 25, 2004, and May 26, 2004, which were 1.4 |ig/L and 1.2
|ig/L, respectively. There was a spike in the concentrate total arsenic (84 |ig/L) just before the
first pre-filter was changed out on April 29, 2004, but returned to approximately 26 |ig/L for the
remainder of the study. The cause of the concentrate arsenic spike is unknown, but was
indirectly substantiated by a corresponding spike in the concentrate TDS. The data
corresponding to Figure 4-8 is presented in Table 4-13. Mass balances were calculated to
determine the accumulation of limiting salts on the membrane surface. Post-treatment
capabilities of the equipment were also evaluated for arsenic (total, As+3, and dissolved).
Additional information on the mass balance for daily total arsenic (feed water, permeate, and
concentrate streams) is presented in Section 4.4.2.1.
90
o
1
M
a
o
U
u
o
H
60 -
30 -
n-n-o-rt
Concentrate
Feed Water
Permeate
o
CN
ON
CN
CN
in
in
in
o
oo
in
o
-------
Table 4-13: Daily Feed Water, Concentrate, and Permeate Total Arsenic Data
Date
Feed Water
Total Arsenic (|Ig/L)
Concentrate
Total Arsenic (|Ig/L)
Permeate
Total Arsenic (|Ig/L)
4/26/04
4/27/04
4/28/04
4/29/04
4/30/04
5/1/04
5/2/04
5/7/04
5/8/04
5/9/04
5/10/04
5/11/04
5/12/04
5/13/04
5/14/04
5/15/04
5/16/04
5/17/04
5/18/04
5/19/04
5/20/04
5/21/04
5/22/04
5/23/04
5/24/04
5/25/04
5/26/04
Average
Minimum
Maximum
Number of Samples
Standard Deviation
95% Confidence Interval
13
13
13
13
13
14
12
12
15
14
13
14
14
13
13
13
13
14
15
14
13
15
14
13
14
15
16
14
12
16
27
1
(13, 14)
39
38
35
84
26
25
25
28
26
28
38
26
27
26
26
25
25
25
26
27
25
26
26
26
25
24
24
30
24
84
27
12
(24, 35)
< 1.0
< 1.0
< 1.0
< 1.0
< 1.0
< 1.0
< 1.0
< 1.0
< 1.0
< 1.0
< 1.0
< 1.0
< 1.0
< 1.0
< 1.0
< 1.0
< 1.0
< 1.0
< 1.0
< 1.0
< 1.0
< 1.0
< 1.0
< 1.0
1.0
1.4
1.2
< 1.0
< 1.0
1.4
27
0.1
(<1.0, 1.1)
In Figure 4-9, Temporal Plot of TDS, the feed water and permeate TDS show steady TDS levels
throughout the verification testing, with standard deviations of 6 and 12 mg/L, respectively. The
permeate TDS was below the detection limit of 10 mg/L at the beginning of the test, and slowly
increased to 34 mg/L on the last day of testing. After the quarterly O&M procedures were
performed, the permeate TDS was reduced by 26% to 34 mg/L (Table 4-12). Throughout the
verification test, the TDS of the concentrate was less than 300 mg/L with the exception of the
first 4 days of the verification testing where the TDS fluctuated as high as 790 mg/L. The data
corresponding to Figure 4-9 is presented in Table 4-14.
69
-------
1000 -r
"Si
800 -
600 -
o
f/3
Q
13
M
o
H
400
200
n-n-n-O-o-OO
o
So
o
^F
iri
m
Concentrate
Feed Water
Permeate
o
o
Verification Testing Date
Figure 4-9 Temporal plot of TDS.
70
-------
Table 4-14: Daily Feed Water, Concentrate, and Permeate TDS
Date
4/26/04
4/27/04
4/28/04
4/29/04
4/30/04
5/1/04
5/2/04
5/7/04
5/8/04
5/9/04
5/10/04
5/11/04
5/12/04
5/13/04
5/14/04
5/15/04
5/16/04
5/17/04
5/18/04
5/19/04
5/20/04
5/21/04
5/22/04
5/23/04
5/24/04
5/25/04
5/26/04
Average
Minimum
Maximum
Number of Samples
Standard Deviation
95% Confidence Interval
Feed Water
TDS (mg/L)
150
140
150
140
1401
ISO1
140
130
150
140
130
130
140
130
1401
140
140
140
140
140
150
138
140
140
150
1301
140
140
130
150
27
7
(138, 143)
Concentrate
TDS (mg/L)
370
390
380
7901
2701
2601
2601
240
250
260
250
270
260
240
250
260
250
230
230
240
240
230
220
230
230
2101
230
279
210
790
27
112
(277, 282)
Permeate
TDS (mg/L)
<10
<10
<10
181
II1
<101
121
<10
11
<10
13
10
19
18
161
24
23
26
24
26
25
32
36
45
45
431
34
21
<10
45
27
12
(19, 23)
Samples exceeded the laboratory RPD of 5%, as indicated in Table 3 -8.
Additional water quality monitoring included daily on-site analysis of pH and twice a day on-site
analysis of conductivity for the feed water, permeate, and concentrate streams. Additional
weekly monitoring was conducted for hardness, alkalinity, and turbidity. Tables 4-15 and 4-16
present the data from the daily pH and conductivity measurements, and Table 4-17 presents the
data from the weekly hardness, alkalinity, and turbidity. Free chlorine and total chlorine were
monitored four times per week on the feed water (chlorinated groundwater) and the permeate
from the first RO membrane (see Table 4-18). Data on additional inorganic constituents
(barium, manganese, calcium, fluoride, chloride, chromium, sulfate, vanadium, iron, and silica)
is presented in Section 4.4.1, which discusses the percent removal of these non-targeted
inorganic chemical constituents.
71
-------
Samples were analyzed daily for pH and twice daily for conductivity from each of the three
sample streams (feed water, permeate, and concentrate). Due to the log nature of pH, the median
value of the pH data has been present in lieu of the average. There was a short range (minimum
to maximum value) of pH values for each of the samples sets with the concentrate having the
greatest variability. The feed water pH ranged from 8.97 to 9.27, concentrate from 8.67 to 9.19
and permeate from 9.23 to 9.66.
Table 4-15: Daily pH Analysis
Date Feed Water Concentrate Permeate
4/26/04
4/27/04
4/28/04
4/29/04
4/30/04
5/1/04
5/2/04
5/7/04
5/8/04
5/9/04
5/10/04
5/11/04
5/12/04
5/13/04
5/14/04
5/15/04
5/16/04
5/17/04
5/18/04
5/19/04
5/20/04
5/21/04
5/22/04
5/23/04
5/24/04
5/25/04
5/26/04
Median
Minimum
Maximum
Number of Samples
9.26
8.98
9.06
9.14
9.09
9.13
8.97
9.09
9.21
9.20
9.08
9.23
9.24
9.10
9.20
9.23
9.20
9.24
9.27
9.24
9.23
9.23
9.21
9.24
9.23
9 22
9.20
9.21
8.97
9.27
27
9.04
8.95
9.01
8.67
9.03
9.10
8.90
9.00
9.12
9.11
9.12
9.14
9.10
9.06
9.11
9.12
9.11
9.14
9.16
9.13
9.19
9.16
9.15
9.16
9.12
9.12
9.15
9.12
8.67
9.19
27
9.43
9.23
9.28
9.30
9.48
9.50
9.49
9.30
9.61
9.56
9.60
9.65
9.66
9.38
9.50
9.57
9.53
9.47
9.49
9.56
9.57
9.52
9.51
9.51
9.48
9.45
9.41
9.50
9.23
9.66
27
The permeate conductivity slowly increased over the 27 operating days of the verification
testing, beginning at 6.7 umoh/cm and ending with 76.7 umoh/cm (see Table 4-16). This is an
indicator of a decline in membrane system performance or membrane integrity. As this decline
was observed even during constant operational conditions, it is suspected that the continued
exposure to low levels of chlorine for the duration of the ETV testing period was leading to
membrane integrity concerns. The conductivity data indicated a relatively steady state for the
feed water and concentrate streams, with one exception on April 29, 2004 where the conductivity
spiked to 1302 umoh/cm in the concentrate.
72
-------
Table 4-16:
Daily Conductivity Analysis
Feed Water (umoh/cm)
Date
4/26/04
4/27/04
4/28/04
4/29/04
4/30/04
5/1/04
5/2/04
5/7/04
5/8/04
5/9/04
5/10/04
5/11/04
5/12/04
5/13/04
5/14/04
5/15/04
5/16/04
5/17/04
5/18/04
5/19/04
5/20/04
5/21/04
5/22/04
5/23/04
5/24/04
5/25/04
5/26/04
Average
Minimum
Maximum
Number of
Samples
Standard
Deviation
95%
Confidence
Interval
AM
190
209
232
236
239
245
233
238
245
245
237
242
240
243
241
240
241
244
224
234
230
224
228
226
225
230
230
233
190
245
27
12
(231,
235)
PM
192
202
233
248
227
243
228
244
214
239
224
246
244
239
244
241
231
237
222
227
222
227
224
228
227
228
228
230
192
248
27
13
(228,
232)
Ave
191
206
233
242
233
244
231
241
230
242
231
244
242
241
243
241
236
241
223
231
226
226
226
227
226
229
229
231
191
244
27
12
(229,
234)
Concentrate (umoh/cm)
AM
505
559
598
1302
431
449
434
423
428
424
426
439
437
414
411
420
416
408
401
398
387
381
377
371
368
393
362
458
362
1302
27
177
(456,
460)
PM
491
554
637
1282
412
440
424
426
425
430
433
439
437
417
414
421
409
398
398
391
374
378
375
374
370
391
361
456
361
1282
27
175
(453,
458)
Ave
498
557
618
1292
422
445
429
425
427
427
430
439
437
416
413
421
413
403
400
395
381
380
376
373
369
392
362
457
362
1292
27
176
(454,
459)
Permeate (umoh/cm)
AM
6.7
7.4
6.8
11.3
11.7
14.1
11.1
23.3
15.7
16.2
18.9
22.3
23.2
25.8
25.6
31.0
38.1
42.8
39.2
44.0
41.3
49.2
55.5
58.3
63.2
72.8
76.5
32
6.7
76.5
27
21
(29, 34)
PM
7.5
5.4
8.2
12.2
B1 112
A1: 7.1
11.2
12.2
15.2
13.2
15.9
18.3
22.8
23.5
24.7
25.8
32.3
35.1
39.8
39.1
40.6
43.3
50.0
53.3
60.1
64.1
74.1
76.7
31
5.4
76.7
27
21
(29, 33)
Ave
7.1
6.4
7.5
11.8
AM: 11.7
PM: 9.2
12.7
11.7
19.3
14.5
16.1
18.6
22.6
23.4
25.3
25.7
31.7
36.6
41.3
39.2
42.3
42.3
49.6
54.4
59.2
63.7
73.5
76.6
31
6.4
76.6
27
21
(29, 33)
B= Before and A= After manual adjustments made to system.
Note: Only the 'after' permeate value and average on April 30, 2004 was used in the statistical calculations.
AM = First sample daily collection.
PM = Second sample daily collection.
Table 4-17 presents the weekly on-site hardness, alkalinity, and turbidity analyses. Feed water
during the test was soft and the system completely removed any hardness present. Permeate
hardness in all of the analyses was 0 mg/L, while the concentrate hardness was approximately
double that of the feed water. Similarly, the alkalinity was reduced by approximately 72% in the
permeate and almost doubled in the concentrate compared to the feed water alkalinity. The
turbidity analysis ranged from 0.25 to 0.55 NTU in the feed water and 0.10 to 0.20 NTU in the
permeate with an average percent turbidity removal of 63%.
73
-------
Table 4-17: On-site Weekly Water Quality Monitoring
Date
4/26/04
5/7/04
5/10/04
5/18/04
5/24/04
Average
Minimum
Maximum
Number of
Samples
Date
4/26/04
5/7/04
5/10/04
5/18/04
5/24/04
Average
Minimum
Maximum
Number of
Samples
Feed
Water
20
22
20
22
4
18
4
22
5
Feed
Water
0.43
0.53
0.51
0.23
0.24
0.40
0.25
0.55
5
Hardness (mg/L)
Concentrate
40
44
44
34
18
36
18
44
5
Turbidity (NTU)
Concentrate
0.50
0.52
0.54
0.28
0.25
0.40
0.25
0.55
5
Permeate
0
0
0
0
0
0
0
0
5
Permeate
0.17
0.13
0.18
0.19
0.10
0.15
0.10
0.20
5
Feed
Water
74
88
82
88
84
83
74
88
5
Alkalinity (mg/L)
Concentrate
206
140
144
130
136
151
130
206
5
Permeate
12
18
22
28
34
23
12
34
5
Table 4-18 presents the results of the free and total chlorine on-site analysis from the feed water
and the permeate (note: permeate samples were collected immediately after the first membrane
which was identified as the first available sample location downstream of the pre-filter).
Since the carbon bloc pre-filter was replaced with a sediment pre-filter, the data presented in
Table 4-18 as been broken into two sets of data, one with the carbon bloc pre-filter and one set
with the sediment pre-filter. The results of the first set of data indicate that the carbon bloc pre-
filter removed 51% of the free chlorine and 53% of the total chlorine. This may have been due
in part to the feed water flow rates not allowing sufficient contact time in the pre-filter for the
carbon bloc to be 100% effective.
Once the sediment pre-filter was placed in service (in lieu of the carbon bloc pre-filter), there
was still a small reduction in chlorine removal, 19% of the free chlorine and 21% of the total
chlorine. It is evident that chlorine is breaking through the pre-filter (with either type of pre-
filter). This may be a contributing factor to the decline in membrane performance during the
verification test and may have a significant long-term impact, which cannot be determined by the
data available from this verification test.
74
-------
Table 4-18: On-Site Free and Total Chlorine Monitoring
Date
4/26/2004
4/27/2004
4/28/2004
4/30/2004
5/7/2004
5/8/2004
5/9/2004
5/10/2004
5/11/2004
5/12/2004
Average
Minimum
Maximum
Number of Samples
Standard Deviation
95% Confidence
Interval
5/14/2004
5/17/2004
5/18/2004
5/19/2004
5/21/2004
5/24/2004
5/25/2004
5/26/2004
Average
Minimum
Maximum
Number of Samples
Standard Deviation
95% Confidence
Interval
Free Chlorine
Feed Water
0.51
0.92
0.98
0.45
0.45
0.71
0.30
0.54
0.56
0.46
0.59
0.30
0.98
10
0.22
(0.40, 0.77)
0.68
0.42
0.38
0.02
0.43
0.21
0.03
0.34
0.31
0.02
0.68
8
0.22
(0.09, 0.54)
(mg/L)
Permeate1
0.27
0.56
0.29
0.26
0.36
0.21
0.12
0.21
0.30
0.35
0.29
0.12
0.56
10
0.12
(0.19,0.39)
0.52
0.40
0.30
0.00
0.19
0.20
0.02
0.33
0.25
0.00
0.52
8
0.18
(0.06, 0.43)
Total Chlorine
Feed Water
0.94
0.92
0.98
0.52
0.43
0.78
0.40
0.55
0.56
0.48
0.66
0.40
0.98
10
0.23
(0.46, 0.85)
0.73
0.42
0.39
0.04
0.44
0.22
0.04
0.34
0.33
0.04
0.73
8
0.23
(0.10,0.56)
(mg/L)
Permeate1
0.27
0.56
0.29
0.26
0.20
0.45
0.18
0.21
0.30
0.36
0.31
0.18
0.56
10
0.12
(0.21, 0.41)
0.48
0.39
0.31
0.02
0.37
0.18
0.02
0.34
0.26
0.02
0.48
8
0.17
(0.09, 0.44)
Permeate chlorine samples were collected just after the first membrane.
4.4.1 Percent Removal of Inorganic Chemical Constituents
Speciated arsenic data is presented in Table 4-19. Three forms of arsenic were evaluated on a
weekly basis: total, dissolved, and arsenite. The majority of the arsenic appears to be in the
dissolved form. There is a noticeable discrepancy on the May 24, 2004 sampling date with
respect to the concentrate samples, where the arsenite is greater than both the dissolved and the
total arsenic. This may be due to a number of issues, including sampling error, laboratory
interference, or other unknown causes of interference.
The arsenate data are calculated values by subtracting the arsenite value from the dissolved
arsenic value. From the data presented, the majority of the arsenic was in the arsenate form, with
the exception of the May 24, 2004 sample where the feed water appears to be primarily in the
arsenite form.
75
-------
Table 4-19: Weekly Speciated Arsenic Analysis
Date1
4/26/04
5/7/04
5/10/04
5/18/04
5/24/04
Average
Minimum
Maximum
Number of
Samples
Total
Arsenic (|Ig/L)
Feed
Water Cone. Perm.
13
12
13
15
14
13
12
15
5
39
28
38
28
25
32
25
39
5
< 1.0
< 1.0
< 1.0
< 1.0
1.0
< 1.0
< 1.0
5
Dissolved
Arsenic (|Ig/L)
Feed
Water Cone. Perm.
16
14
13
14
14
14
13
16
5
39 < 1.0
26 < 1.0
31 <1.0
26 < 1.0
23 1.1
29 < 1.0
23 < 1.0
39 1.1
5 5
Arsenite (|Ig/L)
Feed
Water
< 1.0
< 1.0
< 1.0
1.3
14
3.7
< 1.0
14
5
Cone. Perm.
1.7 1
< 1.0 1
1.4 <
1.4 <
30 <
7.1 1
< 1.0 <
30 1
5
.3
.5
1.0
1.0
1.0
2
.5
5
Arsenate (|Ig/L) 1
Feed
Water
15
13
12
12.7
< 1.0
11
< 1.0
15
5
Cone.
37.3
25
29.6
24.6
< 1.0
24
< 1.0
37.3
5
Perm.
< 1.0
< 1.0
< 1.0
< 1.0
< 1.0
< 1.0
< 1.0
< 1.0
5
1 Arsenate results are calculated values.
The results of the weekly sampling of inorganic constituents and the percent removal of the
inorganic constituents are presented Table 4-20 followed by temporal plots for each significant
inorganic constituent (Figures 4-10 to 4-14). Manganese was not plotted as the feed water,
permeate, and concentrate analyses were all below the MRL of 2.0 ng/L. The testing unit was
effective at reducing the following inorganic constituents to non-detectable levels: barium,
calcium, iron, chromium, and sulfate. Significant levels of fluoride, chloride, and vanadium were
also removed. Silica had a declining rate of removal, beginning with 91% removal and ending
with 21% removal. The level of manganese removal could not be determined, as both the feed
water and permeate concentrations were below the detection limit.
76
-------
Table 4-20: Weekly Analytical Parameters and
Barium
69%
> 74%
> 75%
> 68%
> 73%
> 72%
> 68%
> 75%
5
> 80%
> 79%
> 79%
> 77%
> 79%
> 79%
> 77%
> 80%
5
Chloride (mg/L)
4/26/04
5/7/04
5/10/04
5/18/04
5/24/04
Average
Minimum
Maximum
Number of Samples
8.9
8.4
8.7
8.2
8.2
8.5
8.2
8.9
5
25
16
17
15
15
18
15
25
5
< 1.0
< 1.0
< 1.0
1.1
2.1
1
< 1.0
2.1
5
> 89%
> 88%
> 89%
87%
74%
85%
74%
> 89%
5
Sulfate (mg/L)
4/26/04
5/7/04
5/10/04
5/18/04
5/24/04
Average
Minimum
Maximum
Number of Samples
21
20
21
20
19
20
19
21
5
60
39
41
39
38
43
38
60
5
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
5
> 90%
> 90%
> 90%
> 90%
> 89%
> 90%
> 89%
> 90%
5
Iron (mg/L)
4/26/04
5/7/04
5/10/04
5/18/04
5/24/04
Average
Minimum
Maximum
Number of Samples
0.012
0.033
0.019
0.010
0.023
0.019
0.010
0.033
5
< 0.010
0.028
0.018
< 0.010
0.023
0.018
< 0.010
0.028
5
< 0.010
< 0.010
< 0.010
< 0.010
< 0.010
< 0.010
< 0.010
< 0.010
5
> 17%
> 70%
> 47%
> 0 %
> 57%
38%
> 0 %
> 70%
5
Feed
Water
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
<2.0
5
0.82
0.79
0.80
0.80
0.78
0.80
0.78
0.82
5
13
13
13
13
13
13
13
13
5
45
51
51
49
51
49
45
51
5
14
15
17
15
14
15
14
17
5
Manganese (jig/L)
Concen-
trate Permeate
<2.0 <2.0
<2.0 <2.0
<2.0 <2.0
<2.0 <2.0
<2.0 <2.0
<2.0 <2.0
<2.0 <2.0
<2.0 <2.0
5 5
Fluoride (mg/L)
2.2 < 0.050
1.4 < 0.050
1.4 0.06
1.4 0.16
1.2 0.29
1.5 0.12
1.2 < 0.050
2.2 0.29
5 5
Chromium (jig/L)
36 <1.0
23 <1.0
23 <1.0
24 <1.0
23 <1.0
26 <1.0
23 <1.0
36 <1.0
5 5
Vanadium (Jig/L)
130 <3.0
80 < 3.0
84 < 3.0
90 < 3.0
88 5.3
94 < 3.0
80 < 3.0
130 5.3
5 5
Silica (mg/L)
39 1.2
24 3.4
24 4.2
20 8.4
17 11
25 5.6
17 1.2
39 11
5 5
Percent
Removal
NA
NA
NA
NA
NA
NA
NA
NA
NA
> 94%
> 94%
93%
80%
63%
85%
63%
> 94%
5
> 92%
> 92%
> 92%
> 92%
> 92%
> 92%
> 92%
> 92%
5
> 93%
> 94%
> 94%
> 94%
90%
> 93%
90%
> 94%
5
91%
77%
75%
44%
21%
62%
21%
91%
5
The ">" symbol in the percent removal column indicates that the analysis was below the MRL.
2 NA = Not Applicable; Feed water and permeate were both below the detection limit;
77
-------
-Feed Water
-O Permeate
Concentrate
Verification Testing Date
Figure 4-10: Temporal plot of silica.
2.5
MRL = 0.050 mg/L
o
1.5 -
1 -
0.5 -
Q-
Feed Water
-OPermeate
-D Concentrate
o
o
(N
(N
^t
O
O
CN
O
O
(N
^
1/1
o
o
o
o
(N
o
o
(N
o
o
(N
O
(N
O
O
CN
CN
1/1
Verification Testing Date
Figure 4-11: Temporal plot of fluoride.
78
-------
I o.ois H
Feed Water
Permeate
Concentrate
Verification Testing Date
Figure 4-12: Temporal plot of iron.
30'
25-1
MRL = 1.0 mg/L
a I
c
_o
U 10-.
5-
- Feed Water
-O Permeate
-O- Concentrate
o
o
CN
tS
^
o
o
ts
O
O
-------
70
60-
50-
40-
30-
20-
10-
0
O-
o
o
JN
JN
^
MRL = 2.0 mg/L
-O-
o
o
JN
O
O
(N
Jt
LD
o
o
CN
^
>J->
o
o
(N
o
o
JN
o
o
JN
O
(N
-oo
Feed Water
OPermeate
Cl Concentrate
O
O
JN
JN
i^l
Verification Testing Date
Figure 4-14: Temporal plot of sulfate.
4.4.2 Percent Removal of Organic Constituents
Samples for TOC were also collected on a weekly basis. The results of the sampling indicated
that for this water source, the feed, concentrate and permeate had non-detectable levels of TOC,
see Table 4-21.
Table 4-21: Percent Removal of Organic
Date
4/26/04
5/7/04
5/10/04
5/18/04
5/24/04
Average
Minimum
Maximum
Number of Samples
Total
Feed Water
<0.50
<0.50
<0.50
<0.50
<0.50
<0.50
<0.50
<0.50
5
Constituents
Organic Carbon (mg/L)
Concentrate
<0.50
<0.50
<0.50
<0.50
<0.50
<0.50
<0.50
<0.50
5
Permeate
<0.50
<0.50
<0.50
<0.50
<0.50
<0.50
<0.50
<0.50
5
Percent
Removal
NA1
NA
NA
NA
NA
NA
NA
NA
5
NA = Not applicable as all samples contained non-detectable levels of TOC.
80
-------
4.4.2.1 Mass Balance for Total Arsenic
A mass balance through the M-15,000 RO Treatment System for total arsenic was conducted.
The equation used for the mass balance was previously presented in Equation 3-10: QfCf = QPCP
+ QcwCcw. In this equation, QfCf represents the feed water flow rate multiplied by the feed water
total arsenic concentration, QPCP represents the permeate flow multiplied by the permeate total
arsenic concentration, and lastly, QcwCCw represents the concentrate flow rate multiplied by the
concentrate total arsenic concentration. The total arsenic mass balance was calculated for each
day the M-15,000 RO Treatment System was in operation during the verification test. The data
is graphically presented in Figure 4-15 and the corresponding data is provided in Table 4-22.
Throughout most of the verification test, the total arsenic mass balance was very close, with the
exception of April 29, 2004, and May 10, 2004, where the arsenic concentration in the
concentrate stream was significantly higher (greater than the 95% confidence interval), at 84
(ig/L and 38 |j,g/L respectively.
500
5
a.
OK
o
400 -
300 -
200 -
100 -
H
QpCp+QcwCcw
QfCf
o
-------
Table 4-22: Daily Total Arsenic Mass Balance
Date
4/26/04
4/27/04
4/28/04
4/29/04
4/30/04
5/1/04
5/2/04
5/7/04
5/8/04
5/9/04
5/10/04
5/11/04
5/12/04
5/13/04
5/14/04
5/15/04
5/16/04
5/17/04
5/18/04
5/19/04
5/20/04
5/21/04
5/22/04
5/23/04
5/24/04
5/25/04
5/26/04
Average
Minimum
Maximum
Number of Samples
Standard Deviation
95% Confidence Interval
QfCf
(gpm-Hg/L)
267
254
247
234
234
238
201
276
349
308
280
277
266
332
328
325
332
364
398
350
325
375
343
319
343
375
396
309
201
398
27
54
(284, 333)
Qc + o c
p p ^ccw^cw
(gpm-Hg/L)
268
242
223
450
231
221
221
334
317
319
419
264
266
338
338
325
326
338
364
350
325
344
337
337
325
329
315
313
221
450
27
56
(288, 339)
4.4.2.2 Limiting Salt Concentrations
The limiting salt concentrations were calculated using Equation 3.11 once per week and
compared to standard Solubility Product values to determine if the salt concentrations were
posing a limitation to operational system recovery, presented in Table 4-23. The salts that were
evaluated were calcium carbonate (CaCOs), barium sulfate (BaSO/t), and calcium sulfate
(CaSO4).
Barium Sulfate
As shown in Table 4-23, the solubility product of barium sulfate in the feed water, permeate, and
concentrate was less than the theoretical solubility product, indicating that barium sulfate would
remain in a soluble state.
82
-------
Calcium Carbonate
Each of the calcium carbonate samples (feed water, permeate, and concentrate) samples had
solubility products greater than the theoretical solubility product. Thus, it is expected that
calcium carbonate would precipitate out of each of the three streams. This is a concern for the
long-term operation of the membranes, as the precipitation of salts on the membranes could lead
to fouling resulting in a decline in system performance.
Calcium Sulfate
Each of the calcium sulfate samples (feed water, permeate, and concentrate) samples had
solubility products less than the theoretical solubility product. Thus, calcium sulfate would
remain in solution for of each of the three streams.
Table 4-23: Solubility Products of Limiting Salt Concentrations
Theoretical
Solubility
Product
1.1E-10
6.1E-5
Feed
Water
5.8E-12
6.6E-12
7.6E-12
5.5E-12
6.0E-12
6.7E-12
1.6E-08
1.4E-08
1.5E-08
1.3E-08
1.3E-08
1.5E-08
Permeate Concentrate Theoretical
Barium Sulfate
1.7E-13
1.7E-13
1.8E-13
1.8E-13
1.7E-13
1.8E-13
Calcium Sulfate
3.0E-10
3.0E-10
3.1E-10
3.0E-10
3.0E-10
3.0E-10
Solubility
Product
Feed
Water
Permeate
Concentrate
Calcium Carbonate
4.7E-11
2.4E-11
2.4E-11 8.7E-9
2. IE- 11
2.0E-11
2.3E-11
1.2E-07
5.2E-08
5.7E-08
4.7E-08
4.7E-08
5.2E-08
5.4E-08
6.0E-08
5.8E-08
5.6E-08
5.6E-08
5.6E-08
1.7E-09
2.6E-09
3.2E-09
4.1E-09
4.8E-09
1.9E-08
3.8E-07
1.8E-07
1.9E-07
1.5E-07
1.6E-07
9.7E-08
4.4.3 Removal of TSS
TSS was monitored on a weekly basis, as presented in Table 4-24. The source water for the
verification testing was chlorinated groundwater, and not anticipated to have high-suspended
solids. The feed water, concentrate, and permeate samples collected during the verification
testing all had non-detectable levels of TSS, with a detection limit of 10 mg/L.
83
-------
Table 4-24: Removal of Total Suspended Solids
Date Total Suspended Solids (mg/L)
Feed Water Concentrate Permeate Percent Removal
4/26/04 < 10
5/7/04 < 10
5/10/04 < 10
5/18/04 < 10
5/24/04 < 10
Average < 10
Minimum < 10
Maximum < 10
Number of Samples 5
< 10 < 10 NA1
< 10 < 10 NA
< 10 < 10 NA
< 10 < 10 NA
< 10 < 10 NA
< 10 < 10 NA
< 10 < 10 NA
< 10 < 10 NA
555
NA = Not applicable as all samples contained non-detectable levels of TOC.
4.4.4 SDI
SDI is the measurement of the quantity of suspended solids in a water supply that could
potentially foul RO membranes. A 5-gallon sample of the feed water was collected on the last
day of the verification testing. The SDI measurements were run in duplicate from this sample
and found to be 3.12 and 3.10. The SDI results reveal relatively solids free water, which is
consistent with the TSS analyses (all TSS samples were below the MDL of 10 mg/L). The filter
volume for each test was 250 milliliter (mL) and Pall Acrodisk 25-mm syringe filters (0.45 |j,m
diameter) were used for study. A blank SDI was run using de-ionized (DI) water, with a result of
2.57. The results of the SDI test and the method are available in Appendix E.
4.4.5 LSI
The LSI was calculated at the beginning of the verification testing (April 26, 2004) with the
following equation: LSI = pH - pHs, where pH is the measured pH of the water and pH is the pH
at saturation (calcium carbonate).
pHs = (9.3 + A + B) - (C + D).
where: A = (Logic [TDS] - 1) / 10
B = -13.12 x Logio (°C + 273) + 34.55
C = Logic [Ca2+ as CaCCb] - 0.4
D = Logic [alkalinity as CaCOs]
The LSI is an indictor of how corrosive or scaling a water may be primarily based on the TDS,
calcium, water temperature, and alkalinity. On April 26, 2004 the LSI of the feed water,
permeate, and concentrate was calculated and the data is presented in Table 4-25. From the
calculation, the feed water is at equilibrium, the permeate is slightly corrosive and the
concentrate is in a slightly scaling state.
84
-------
Table 4-25:
A
B
C
D
pH
pHs
LSI
LSI Calculations (April 26, 2004)
Feed water
0.1176
2.0218
0.3076
1.8692
9.26
9.26
0.00
Permeate
0.0000
2.0218
-0.4000
1.0792
9.43
10.64
-1.21
Concentrate
0.1568
2.0218
0.7139
2.3139
9.04
8.45
0.59
4.5 Task 4: Data Handling Protocol
The objective of this task was to establish an effective field protocol for data management at the
field operations site and for data transmission between the FTO and NSF during verification
testing. Prior to the beginning of field testing, the database or spreadsheet design was developed
by the FTO and reviewed and approved by NSF. This ensured that the required data was
collected during the testing, and that results could be effectively transmitted to NSF for review.
The FTO followed all data handling procedures that were presented in Chapter 3. Additional
details on data handling were previously discussed in Section 3.11.
4.6 Task 5: Quality Assurance/Quality Control Results
An important aspect of verification testing is the Quality Assurance Project Plan (QAPP)
developed for QA/QC, as described in Section 3.12. The objective of this task was to assure
accurate measurement of operational and water quality parameters during membrane equipment
verification testing. The primary areas of evaluation were precision, accuracy, statistical
uncertainty, and completeness. Statistical uncertainty was discussed in Section 3.12.4.2 and
presented in tables containing eight or more data sets, presented in Chapter 4 as the 95%
confidence interval.
Each day the tubing, fittings, and general condition of the M-15,000 RO Treatment System were
inspected to verify that there were no leaks or needed repairs. There were no leaks to report
from tubing, however daily inspection of the membrane housings revealed intermittent leaks,
which alternated between each of the six housings, as noted in the field logbook.
4.6.1 Precision
Precision refers to the degree of mutual agreement among individual measurements, and was
discussed in Section 3.12.5 and 3.12.6. The percent acceptable precision among duplicate
samples was previously presented in Table 3-7 and the calculated precision for each analytical
parameter is presented in the following tables. The precision calculations of the weekly off-site
duplicate analyses are presented in Table 4-26 and the weekly on-site duplicate analyses are
presented in Table 4-27. Note that only the feed water and permeate samples were taken in
duplicate for the on-site duplicate analysis of chlorine (free and total) and that only the feed
water was taken in duplicate for temperature (twice weekly). All analyses presented in Tables 4-
85
-------
26 and 4-27 were within the acceptable precision percentage, with the exception of one free
chlorine sample collected on May 19, 2004 (47% precision), which had very low levels of
chlorine (0.02 and 0.01 mg/L in the sample and duplicate, respectively), and eight of the twenty-
seven pH duplicate samples. Analytical precision was calculated for pH based on duplicate
samples that were collected seven times per week. The pH values were converted to hydrogen
ion concentrations and the percent precision was calculated from the hydrogen ion concentration.
For the data presented in Table 4-27, the hydrogen ion concentration was calculated as:
pH = - log [Hydrogen ion concentration]
TDS duplicates were collected four times per week and the data is presented in Table 4-28. All
TDS duplicate analyses were within the acceptable precision percentage of 30%. Conductivity
duplicates were collected eight times per week and the data is presented in Table 4-29. Total
arsenic duplicates were collected daily, with the results of the duplicate precision analysis
presented in Table 4-30. The percent precision values for all the conductivity and total arsenic
data sets were within the acceptable limits. An SDI measurement was required once during the
verification testing period. The water for this analysis was collected in duplicate on May 26,
2004, with a percent precision of 0.6%.
Precision checks performed by the MWH Laboratory were within the acceptable limits outlined
in Table 3-8, except for some TDS samples, as indicated in Table 4-14.
86
-------
Table 4-26
Date
4/26/04
5/7/04
5/10/04
5/18/04
5/24/04
4/26/04
5/7/04
5/10/04
5/18/04
5/24/04
4/26/04
5/7/04
5/10/04
5/18/04
5/24/04
4/26/04
5/7/04
5/10/04
5/18/04
5/24/04
4/26/04
5/7/04
5/10/04
5/18/04
5/24/04
: Weekly Off-Site Analytical
Barium (|Ig/L)
Sample
Location Sample Duplicate
permeate < 2.0 < 2.0
concentrate 14 14
feed water 8.1 7.4
permeate < 2.0 < 2.0
concentrate 12 12
Acceptable Precision
Calcium (mg/L)
permeate < 1.0 < 1.0
concentrate 9.1 9.1
feed water 4.8 4.8
permeate < 1.0 < 1.0
concentrate 8.4 8.5
Acceptable Precision
Chloride (mg/L)
permeate < 1.0 < 1.0
concentrate 16 17
feed water 8.7 8.7
permeate 1.1 1.1
concentrate 15 15
Acceptable Precision
Sulfate (mg/L)
permeate < 2.0 < 2.0
concentrate 39 39
feed water 21 21
permeate < 2.0 < 2.0
concentrate 38 38
Acceptable Precision
Iron (mg/L)
permeate < 0.010 < 0.010
concentrate 0.028 0.042
feed water 0.019 0.019
permeate < 0.010 < 0.010
concentrate 0.023 0.022
Acceptable Precision
Precision
Percent
Precision
0.0%
0.0%
6.0%
0.0%
0.0%
30%
0.0%
0.0%
0.0%
0.0%
1.0%
30%
0.0%
4.0%
0.0%
0.0%
0.0%
20%
0.0%
0.0%
0.0%
0.0%
0.0%
20%
0.0%
28%
0.0%
0.0%
3.0%
30%
TOC (mg/)
4/26/04
5/7/04
5/10/04
5/18/04
5/24/04
permeate < 0.50 < 0.50
concentrate < 0.50 < 0.50
feed water < 0.50 < 0.50
permeate < 0.50 < 0.50
concentrate < 0.50 < 0.50
Acceptable Precision
0.0%
0.0%
0.0%
0.0%
0.0%
30%
Sample
Location
permeate
concentrate
feed water
permeate
concentrate
permeate
concentrate
feed water
permeate
concentrate
permeate
concentrate
feed water
permeate
concentrate
permeate
concentrate
feed water
permeate
concentrate
permeate
concentrate
feed water
permeate
concentrate
Manganese (|Ig/L)
Sample Duplicate
<2.0 <2.0
<2.0 <2.0
<2.0 <2.0
<2.0 <2.0
<2.0 <2.0
Acceptable Precision
Fluoride (mg/L)
< 0.050 < 0.050
1.4 1.4
0.80 0.8
0.16 0.16
1.2 1.2
Acceptable Precision
Chromium (|Ig/L)
< 1.0 <1.0
23 22
13 13
< 1.0 <1.0
23 23
Acceptable Precision
Vanadium (|Ig/L)
<3.0 <3.0
80 80
51 45
<3.0 <3.0
88 87
Acceptable Precision
Silica (mg/L)
1.2 1.2
24 24
17 15
8.4 8.4
17 17
Acceptable Precision
Percent
Precision
0.0%
0.0%
0.0%
0.0%
0.0%
30%
0.0%
0.0%
0.0%
0.0%
0.0%
20%
0.0%
3.0%
0.0%
0.0%
0.0%
30%
0.0%
0.0%
9.0%
0.0%
1.0%
30%
0.0%
0.0%
9.0%
0.0%
0.0%
30%
TSS (mg/L)
permeate
concentrate
feed water
permeate
concentrate
< 10 < 10
< 10 < 10
< 10 < 10
< 10 < 10
< 10 < 10
Acceptable Precision
0.0%
0.0%
0.0%
0.0%
0.0%
30%
87
-------
Table 4-27
Date
4/26/04
5/7/04
5/10/04
5/18/04
5/24/04
4/26/2004
4/28/2004
4/30/2004
5/2/2004
5/7/2004
5/9/2004
5/10/2004
5/12/2004
5/14/2004
5/18/2004
5/19/2004
5/21/2004
5/24/2004
5/26/2004
4/26/04
4/30/04
5/7/04
5/10/04
5/14/04
5/18/04
5/21/04
5/24/04
: On-Site Analytical Precision
Hardness (mg/L)
Sample
Percent
Location Sample Duplicate Precision
permeate 0 0
concentrate 44 42
feed water 20 22
permeate 0 0
concentrate 18 20
Acceptable Precision
Free Chlorine (mg/L)
permeate 0.27 0.28
feed water 0.98 0.97
feed water 0.45 0.46
permeate 0.13 0.14
feed water 0.45 0.45
permeate 0.12 0.16
feed water 0.54 0.50
permeate 0.35 0.29
permeate 0.52 0.51
permeate 0.30 0.39
feed water 0.02 0.01
feed water 0.43 0.44
feed water 0.21 0.20
permeate 0.33 0.33
Acceptable Precision
Temperature ("C)1
feed water 29.0 29.0
feed water 27.5 27.5
feed water 27.5 27.5
feed water 27.0 27.0
feed water 28.5 28.5
feed water 27.0 27.0
feed water 28.0 28.0
feed water 27.0 27.0
Acceptable Precision
0.0%
3.0%
7.0%
0.0%
7.0%
30%
2.6%
0.7%
1.6%
5.2%
0.0%
20%
5.4%
13%
1.4%
18%
47%
1.6%
3.4%
0.0%
30%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
10%
Sample
Location
permeate
concentrate
feed water
permeate
concentrate
Alkalinity
Sample
12
140
82
28
136
(mg/L)
Duplicate
12
138
84
30
134
Acceptable Precision
Percent
Precision
0.0%
1.0%
2.0%
5.0%
1.0%
30%
Total Chlorine (mg/L)
permeate
feed water
feed water
permeate
feed water
permeate
feed water
permeate
permeate
permeate
feed water
feed water
feed water
permeate
permeate
concentrate
feed water
permeate
concentrate
0.27
0.98
0.52
0.14
0.43
0.18
0.55
0.36
0.48
0.31
0.04
0.44
0.22
0.34
Acceptable
Turbidity
0.17
0.52
0.51
0.19
0.25
0.28
0.98
0.50
0.15
0.46
0.20
0.52
0.30
0.51
0.40
0.04
0.44
0.19
0.33
Precision
(NTTJ)
0.16
0.54
0.52
0.20
0.24
Acceptable Precision
2.6%
0.0%
2.8%
4.9%
4.8%
7.4%
4.0%
13%
4.3%
18%
0.0%
0.0%
10%
2.1%
30%
4.0%
3.0%
1.0%
4.0%
3.0%
30%
88
-------
Table 4-27: On-Site Analytical
pH
Sample
Date Location Sample
4/26/04
4/27/04
4/28/04
4/29/04
4/30/04
5/1/04
5/2/04
5/7/04
5/8/04
5/9/04
5/10/04
5/11/04
5/12/04
5/13/04
5/14/04
5/15/04
5/16/04
5/17/04
5/18/04
5/19/04
5/20/04
5/21/04
5/22/04
5/23/04
5/24/04
5/25/04
5/26/04
permeate
concentrate
feed water
permeate
concentrate
feed water
permeate
concentrate
feed water
permeate
feed water
permeate
concentrate
feed water
permeate
concentrate
feed water
concentrate
permeate
feed water
permeate
concentrate
feed water
permeate
concentrate
feed water
permeate
9.43
8.95
9.06
9.30
9.03
9.13
9.49
9.00
9.21
9.56
9.08
9.65
9.10
9.10
9.50
9.12
9.20
9.14
9.49
9.24
9.57
9.16
9.21
9.51
9.12
9.22
9.41
Acceptable
Precision
Duplicate
9.44
9.01
9.12
9.26
9.04
9.19
9.44
9.07
9.19
9.58
9.10
9.60
9.11
9.00
9.52
9.11
9.20
9.12
9.52
9.24
9.52
9.15
9.21
9.51
9.12
9.20
9.42
Precision
(continued)
Percent
Precision
2%
14%2
14%2
9%
2%
14%2
12%2
16%2
5%
5%
5%
12%2
2%
23%2
5%
2%
0%
5%
7%
0%
12%2
2%
0%
0%
0%
5%
2%
10%
Temperature duplicates were taken twice weekly and only on the feed water.
Exceeded the precision limit of 10%, as defined in Table 3-7.
89
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Table 4-28:
Date
4/26/04
4/28/04
4/30/04
5/2/04
5/7/04
5/9/04
5/10/04
5/12/04
5/14/04
5/16/04
5/18/04
5/19/04
5/20/04
5/21/04
5/23/04
5/24/04
5/26/04
TDS Analytical Precision
Sample Location
permeate
feed water
concentrate
permeate
concentrate
permeate
feed water
concentrate
permeate
feed water
permeate
feed water
permeate
concentrate
permeate
concentrate
permeate
Sample TDS
(mg/L)
<10
150
270
12
240
<10
130
260
16
140
24
140
25
230
45
230
34
Duplicate TDS
(mg/L)
<10
140
260
13
250
14
130
250
12
140
25
130
26
230
37
230
34
Acceptable Precision
Percent
Precision
0%
5%
3%
6%
3%
24%
0%
3%
20%
0%
3%
5%
3%
0%
14%
0%
0%
30%
90
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Table 4-29: Daily Conductivity Precision Analysis
Date
4/26/04
4/27/04
4/28/04
4/29/04
4/30/04
5/1/04
5/2/04
5/2/04
5/7/04
5/8/04
5/9/04
5/10/04
5/11/04
5/12/04
5/13/04
5/14/04
5/15/04
5/16/04
5/16/04
5/17/04
5/18/04
5/19/04
5/20/04
5/21/04
5/22/04
5/23/04
5/23/04
5/24/04
5/25/04
5/26/04
5/26/04
1 The duplicate
logbook.
Sample Location
permeate
concentrate
feed water
permeate
concentrate
feed water
permeate
permeate
concentrate
feed water
permeate
feed water
permeate
concentrate
concentrate1
permeate
concentrate
feed water
feed water
concentrate
permeate
feed water
permeate
concentrate
feed water
permeate
permeate
concentrate
feed water
permeate
permeate
conductivity value was taken
Sample
Conductivity
(umoh/cm)
6.7
554
232
11.3
412
245
11.1
11.1
426
245
16.2
237
22.8
437
417
25.8
420
241
241
398
39.2
234
41.3
378
228
58.3
58.3
368
230
76.5
76.5
on the concentrate
Duplicate
Conductivity
(umoh/cm)
6.7
556
230
11.5
431
247
12.2
12.1
425
244
16.4
235
22.7
436
438
25.8
421
240
241
406
39.6
234
41.4
380
229
58.2
58.4
369
230
76.6
76.8
Acceptable Precision
water and not the feed water,
Percent
Precision
0.00%
0.25%
0.61%
1.24%
3.19%
0.57%
6.68%
6.10%
0.17%
0.29%
0.87%
0.60%
0.31%
0.16%
3.47%
0.00%
0.17%
0.29%
0.00%
1.41%
0.72%
0.00%
0.17%
0.37%
0.31%
0.12%
0.12%
0.19%
0.00%
0.09%
0.28%
10%
as indicated in the
91
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Table 4-30: Daily Total Arsenic Precision Analysis
Date
Sample Location
Sample Arsenic Duplicate Arsenic
Precision
4/26/04
4/27/04
4/28/04
4/29/04
4/30/04
5/1/04
5/2/04
5/7/04
5/8/04
5/9/04
5/10/04
5/11/04
5/12/04
5/13/04
5/14/04
5/15/04
5/16/04
5/17/04
5/18/04
5/19/04
5/20/04
5/21/04
5/22/04
5/23/04
5/24/04
5/25/04
5/26/04
permeate
concentrate
feed water
permeate
concentrate
feed water
permeate
concentrate
feed water
permeate
feed water
permeate
concentrate
feed water
permeate
concentrate
feed water
concentrate
permeate
feed water
permeate
concentrate
feed water
permeate
concentrate
feed water
permeate
< 1.0
38
13
< 1.0
26
14
< 1.0
28
15
< 1.0
13
< 1.0
27
13
< 1.0
25
13
25
< 1.0
14
< 1.0
26
14
< 1.0
25
15
1.2
< 1.0
36
12
< 1.0
26
14
< 1.0
27
14
< 1.0
13
< 1.0
26
14
< 1.0
24
13
26
< 1.0
14
< 1.0
24
14
< 1.0
24
15
< 1.0
Acceptable Precision
0%
4%
6%
0%
0%
0%
0%
3%
5%
0%
0%
0%
3%
5%
0%
3%
0%
3%
0%
0%
0%
6%
0%
0%
3%
0%
0%
30%
4.6.2 Accuracy
Arsenic Speciation and Analysis
Total arsenic samples were collected daily according to EPA Method 200.8. Additional arsenic
samples were collected weekly for As3+ and dissolved arsenic. The field speciation columns
were provided by NSF. QA/QC evaluations of the speciation columns using known
concentrations of As3+ and As5+ were conducted by the NSF laboratory prior to the verification
test.
One concentrate sample (collected May 24, 2004) indicated higher As3+ than total arsenic.
While it is not reasonable for a single species of arsenic to have a higher concentration than the
total, it is further perplexing to measure a detectable concentration of As3+ as this water source is
chlorinated. There is currently no explanation for these results. Furthermore, 10% of the
samples showed slightly higher dissolved arsenic concentrations than total arsenic. However,
these samples were just slightly higher than the total arsenic and primarily found in the
concentrate samples. On April 26, 2004 the dissolved arsenic concentration in the concentrate
was 16 |ig/L, with a total arsenic of 13 |ig/L, and on May 7 the dissolved arsenic concentration in
the concentrate was 14 |ig/L, with a total arsenic of 12 |ig/L. On May 24, 2004, the dissolved
92
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arsenic of 1.1 |ig/L with a total arsenic of <1.0 |ig/L. Accuracy checks for arsenic samples
performed by the MWH Laboratory were within the acceptable limits outlined in Table 3-8.
Other Laboratory Parameters
Accuracy checks performed by the MWH Laboratory for all samples analyzed by the laboratory
were within the acceptable limits outlined in Table 3-8.
pH Meter
The pH meter was calibrated daily using certified pH solutions (4.0, 7.0 and 10.0) from Hach.
Analyses were made daily according to Standard Method 4500-H+B.
Temperature
Table 3-7 indicates that temperature was to be verified weekly against a NIST-certified
thermometer. Since the feed water temperature was measured twice daily using a NIST-certified
thermometer, no accuracy checks were necessary.
Alkalinity
Two sets of four known samples were analyzed during the verification test to verify the accuracy
of the onsite test method. The accuracy checks are discussed in additional detail in Section 4.6.3
with corresponding data provided in Table 4-32, with all results being within the acceptable
accuracy range of + 30% recovery.
Hardness
Two sets of four known samples were analyzed during the verification test to verify the accuracy
of the onsite test method. The accuracy checks are discussed in additional detail in Section 4.6.3
with corresponding data provided in Table 4-32, with all results being within the acceptable
accuracy range of + 30% recovery.
Turbidity Instrumentation
The turbidity meter was calibrated each day the instrument was in use. Calibrations were made
using both primary and secondary standards provided by Hach. Each calibration was also
checked against standards in the anticipated turbidity range of the samples (0.1, 0.5 and 5 NTU).
Conductivity Meter
The handheld conductivity meter was used according to StandardMethod2510 B. A three-point
calibration with certified conductivity solutions (184, 1000, and 1990 umoh/cm) was made each
day the meter was in use.
Chlorine Meter
The chlorine meter was checked for accuracy through the use of known spike samples provided
by Hach with the Hach 8167 method for total chlorine and Hach 8021 method for free chlorine,
at a frequency of three times during the verification testing. The accuracy of the free and total
chlorine spikes is discussed in additional detail in Section 4.6.3 with corresponding data
provided in Table 4-32, with all results being within the acceptable accuracy range of + 30%
recovery.
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Flow Monitoring
The M-15,000 RO Treatment System was equipped with panel mounted flow meters to read the
permeate and concentrate flow rates and were checked daily using the "calibrated container and
stopwatch" method. The flow meters appeared to be accurate according to this method of
calibration, with an average accuracy of 98% for both the concentrate and permeate flow rates.
The flow meters were not designed to allow adjustment or calibration, so the differences (when
present) were recorded, however, no adjustments could be made to "calibrate" the flow meters.
Table 4-31 presents the results of the daily permeate and concentrate flow rate checks and the
percent accuracy of the panel mounted flow meters.
Pressure Gauges
Watts Premier indicated that the pressure gauges installed were factory-calibrated; no additional
accuracy checks were performed.
Table 4-31:
Date
4/26/04
4/27/04
4/28/04
4/29/04
4/30/04
5/1/04
5/2/04
5/7/04
5/8/04
5/9/04
5/10/04
5/11/04
5/12/04
5/13/04
5/14/04
5/15/04
5/16/04
5/17/04
5/18/04
5/19/04
5/20/04
5/21/04
5/22/04
5/23/04
5/24/04
5/25/04
5/26/04
Daily Permeate and Concentrate Flow
Known
Permeate
Flow Rate
(gpm)1
14.00
13.50
13.00
12.80
9.50
8.50
8.25
11.50
11.50
11.00
10.75
10.00
9.50
13.00
12.75
12.50
13.00
13.00
13.00
12.50
12.50
12.25
12.00
12.00
12.00
12.00
12.25
Measured
Permeate
Flow
Rate (gpm)
14.00
13.50
12.50
12.50
9.00
8.50
8.25
10.25
11.50
11.00
10.50
10.00
9.50
9.25
12.50
12.50
13.00
13.00
13.00
12.50
12.50
12.50
12.00
12.00
12.00
12.00
12.50
Average
Minimum
Maximum
% Accuracy
of Panel
Mounted
Permeate
Flow Meter
100%
100%
96%
98%
95%
100%
100%
89%
100%
100%
98%
100%
100%
71%
98%
100%
100%
100%
100%
100%
100%
98%
100%
100%
100%
100%
98%
98%
71%
100%
Rate Checks
Known
Concentrate
Flow Rate
(gpm)
6.50
6.00
6.00
5.20
8.50
8.50
8.50
11.50
11.75
11.00
10.75
9.75
9.50
12.50
12.50
12.50
12.50
13.00
13.50
12.50
12.50
12.75
12.50
12.50
12.50
13.00
12.50
(Calibration)
Measured
Concentrate
Flow Rate
(gpm)
6.50
6.00
6.00
5.25
8.50
8.50
8.25
10.25
11.75
11.00
10.75
9.50
9.50
8.50
12.50
12.50
12.50
13.00
13.00
12.50
12.50
12.50
12.50
12.50
12.50
13.00
12.50
Average
Minimum
Maximum
% Accuracy
of Panel
Mounted
Concentrate
Flow Meter
100%
100%
100%
99%
100%
100%
97%
89%
100%
100%
100%
97%
100%
68%
100%
100%
100%
100%
96%
100%
100%
98%
100%
100%
100%
100%
100%
98%
68%
100%
94
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Table 4-32:
Date
5/2/04
6/16/04
5/24/04
Date
5/2/04
5/16/04
Spike Data for Free and Total Chlorine,
Free Chlorine
Spike (mg/L) Value (mg/L) Accuracy
0
0.25
0.50
0.75
0
0.25
0.50
0.75
0
0.25
0.50
0.75
0
0.25
0.49
0.74
0
0.25
0.50
0.75
0
0.25
0.49
0.74
Acceptable Accuracy
Hardness
Spike (mg/L) Value (mg/L)
0
1.0
2.0
3.0
0
1.0
2.0
3.0
0
1.0
2.0
3.0
0
1.1
2.1
3.2
Acceptable Accuracy
0.0%
0.0%
2.0%
1.3%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
2.0%
1.3%
30%
Accuracy
0.0%
0.0%
0.0%
0.0%
0.0%
9.1%
4.8%
6.3%
30%
Hardness, and Alkalinity
Total Chlorine
Spike (mg/L) Value (mg/L)
0
0.25
0.50
0.75
0
0.25
0.50
0.75
0
0.25
0.50
0.75
0.02
0.23
0.45
0.72
0
0.24
0.50
0.75
0
0.24
0.49
0.73
Acceptable Accuracy
Spike (mg/L)
0
3.0
5.5
7.0
0
3.0
5.5
7.0
Alkalinity
Value (mg/L)
0
3.0
5.5
8.0
0.0
2.5
5.0
7.4
Acceptable Accuracy
Accuracy
0.0%
8.0%
10.0%
4.0%
0.0%
4.0%
0.0%
0.0%
0.0%
4.0%
2.0%
2.7%
30%
Accuracy
0.0%
0.0%
0.0%
13%
0.0%
17%
9.1%
5.4%
30%
4.6.3 Off-Site Analysis of Samples
4.6.3.1 Inorganic Samples
Inorganic samples were collected in accordance with the Standard Methods and EPA methods
listed in Table 3-6. All samples were stored in a refrigerator, held at 4°C until shipment to the
off-site analytical lab (MWH Laboratories). Samples were shipped with chain-of-custody in
coolers packed with blue ice. All samples were analyzed within the required holding times.
4.6.3.2 Organic Samples
TOC was sampled six times throughout the verification testing. All samples were collected in
amber glass bottles, stored at 4°C, and shipped in coolers packed with blue ice. All samples
were analyzed according to Standard Method 53IOC within the required holding times. All
results were below the MDL of 0.50 mg/L. All spikes, duplicates, and precision analyses were
within the required testing parameters, as presented in Table 3-8.
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4.6.4 Completeness
Calculation of data completeness was made for on-site water quality measurements and MWH
Laboratory water quality measurements, as explained in Section 3.12.4.4. During the
verification test, duplicate samples were collected in a rotating manner (i.e., duplicates were
taken of the feed water during one round of duplicate analysis, then permeate samples, and
finally concentrate samples). Based on the completeness goals defined in Table 3-11 and the
completeness results in Table 4-33, all parameters were within the stated completeness goals.
Table 4-33: Completeness
Parameter
Proposed1 Actual
Results Duplicates Results Duplicates
Completeness (%)
Results Duplicates
Completeness Goal
Results Duplicates
Arsenic (Total)
Arsenic
(Speciated)
pH
Silica
Fluoride
Chromium
Vanadium
TOC
Chloride
Iron
Manganese
Sulfate
Temperature
Alkalinity
Hardness
Turbidity
Conductivity
Barium
Calcium
TSS
SDI
TDS
Free Chlorine
Total Chlorine
81
15
81
15
15
15
15
15
15
15
15
15
54
15
15
15
162
15
15
15
1
81
36
36
27
NA
27
5
5
5
5
5
5
5
5
5
10
5
5
5
33
5
5
5
1
17
9
9
81
15
81
15
15
15
15
15
15
15
15
15
54
15
15
15
162
15
15
15
1
81
36
36
27
NA
27
5
5
5
5
5
5
5
5
5
8
5
5
5
31
5
5
5
1
17
17
17
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
NA
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
80%
100%
100%
100%
94%
100%
100%
100%
100%
100%
>100%
>100%
95%
90%
95%
90%
90%
90%
90%
90%
90%
90%
90%
90%
95%
90%
90%
90%
95%
90%
90%
90%
80%
95%
90%
90%
90%
NA
90%
80%
80%
80%
80%
80%
80%
80%
80%
80%
80%
80%
80%
80%
90%
80%
80%
80%
80%
90%
90%
90%
Based on 27 days of testing.
Based on completeness guidelines outlined in Table 3-11.
4.6.5 NSF Field Inspection
On May 13, 2004, NSF conducted a field inspection of the verification test and found the
practices in place on-site to be in accordance with the PSTP that was approved prior to beginning
the testing.
96
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Chapter 5
References
The following references were used in the preparation of this report:
Methods for Chemical Analysis of Water and Wastes (MCAWW) EPA/600/4-79-202 - Revised
March 1983.
Methods for Determination of Organic Compounds in Drinking Water - EPA/600/4-8 8/03 9-
December 1988 (Revised July 1991).
Standard Methods for the Examination of Water and Wastewater. 1999. 20th edition. APHA,
AWWA, and WEF, Washington D.C.
U.S. EPA/NSF International. EPA/NSF ETV Protocol for Equipment Verification Testing for
Arsenic Removal, September 2003.
U.S. EPA/NSF International. EPA/NSF ETV Protocol for Equipment Verification Testing for
Removal of Inorganic Constituents, April 2002.
97
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Chapter 6
Vendor Comments
Watts Premier submitted the following comments concerning the ETV test and report. These
statements were not validated in the verification test and are the opinion of Watts Premier:
"4.2.1 General Operational Performance
Just prior to the commencement of the ETV project and installation of the M-15,000 RO system
it was discovered that the water entering the reverse osmosis unit would be chlorinated. At this
time based upon the water parameters that were provided, and given the consideration that this
would be a one month duration test, a 4" x 20" carbon filter was used as pre-filtration for the RO
unit. It was agreed that under these conditions this testing would certainly provide a "worst case"
arsenic reduction test protocol for the M-15,000 RO unit.
Seven days in to the arsenic reduction testing of the RO unit, the motor on the M-15,000 seized.
It was discovered during the replacement of the pump that the pre filter to the M-15,000 unit was
completely plugged. Upon further investigation by MWH field staff, it was discovered that the
periodic operation of the CVWD Well 7802 introduced a significant slug of solids with each
start-up, which then plugged the carbon pre-filter. With the plugging of the carbon prefilter, the
pump seized due to loss of water to the motor.
Once the pump was replaced and the pre filtration switched to a 20 micron sediment filter, RO
system operation stabilized.
Due to the tight time line and the relatively short duration of the test, Watts Premier suggested
the use of a sediment pre filter to the RO unit. With only a few weeks remaining in the project
testing phase, this chlorine contact on the RO membrane would represent an even further "worst-
case" evaluation of reduction capabilities. This would provide valuable information to Watts
Premier and the industry in regards to the operation of the M-15,000 RO unit.
Looking at several parameters with in this report, including feed water flow rate decreasing, flux
reduction, increase in permeate conductivity it is evident that the chlorine did in fact have a
negative effect on the overall reduction capabilities of the membranes. Permanent installation
and operation of the Ml5,000 unit would include a thorough review of the water system
operation, which would have revealed the solids that CVWD Well 7802 introduced in to the
system. Based upon this information, and the presence of chlorine, permanent installation of an
M-15,000 would include proper filtration prior to the M series reverse osmosis unit to remove
the chlorine and sufficient sediment filtration capabilities to efficiently handle the frequent slug
of solids that the CVWD Well 7802 discharged to the water treatment system.
4.3 Task 2: Cleaning Efficiency
M series of RO units are available for systems that feed both in to a pressure tank, as well as a
float tank apparatus. Each system is designed to go through a self initiated rinse cycle of the RO
membranes. This rinse cycle occurs at either the unit shut down for units operating on short duty
98
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cycles or on timed periodic schedule for those systems operating on extended duty cycles. This
cleaning cycle is used in order to remove solids and other salts from the membrane, therefore
prolonging the life of each membrane module. During normal operation where water is being
discharged to a permanent tank, this flushing procedure would commence each time the tank is
filled, and the M-15,000 system goes in to standby mode. During this ETV test, the M-15,000
unit was on continuously for the duration of the testing. Based upon this quantity of water being
treated, this flushing cycle would have occurred more frequently under normal operation
procedures than what was conducted during this evaluation.
Based upon the results obtained through this ETV testing protocol, the M series of commercial
reverse osmosis systems has proven to be a viable means of processing water for the intent of
domestic or industrial use.
Watts Premier would like to thank the hard work of all participants from MWH and NSF in
completing this ETV project. All of their hard work on this project has been greatly
appreciated."
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