September 2005
NSF 05/20/EPADWCTR
EPA/600/R-05/119
Environmental Technology
Verification Report
Removal of Arsenic in Drinking Water
ORCA Water Technologies
KemLoop 1000 Coagulation and
Filtration Water 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
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ABSTRACT
Verification testing of the ORCA Water Technologies KemLoop 1000 Coagulation and Filtration Water
Treatment System for arsenic removal was conducted at the St. Louis Center located in Washtenaw
County, Michigan from March 23 through April 6, 2005. The source water was groundwater from two
supply wells, and the raw water for the verification test was withdrawn from the pressure tank at the site.
Verification testing was conducted at the operating conditions specified by the manufacturer. The raw
water, with a pH in the range of 7.0 to 7.6, was treated with chlorine bleach to oxidize arsenic (III) to
arsenic (V), as well as iron to coagulate the arsenic. When operated under the manufacturer's specified
conditions at this site, at an average flow rate of 9.9 gallons per minute (gpm), the KemLoop System
reduced the total arsenic concentration from an average of 22 micrograms per liter (ug/L) in the feed
water (raw water after chemical addition) to 3 ug/L in the filtrate (treated) water.
TECHNOLOGY DESCRIPTION
The following technology description was provided by the manufacturer and has not been verified.
The ORCA process is based on chemical addition with mixing in a proprietary mixing loop to optimize
coagulation, and granular media filtration with no intermediate solids separation process. The KemLoop
System includes pretreatment with sodium hypochlorite to oxidize any arsenic (III) to arsenic (V), and
iron present in the water supply. Ferric chloride is added to augment any natural occurring iron and
optimize the iron dose. The chemically treated water (feed water) enters the mixing loop where
coagulation of arsenic and iron occurs. The water exits the mixing loop and is applied directly to one of
the two granular media filter modules. The water enters the top of the operating filter and flows through
the granular media filter, exiting at the bottom of the module. The granular media filter removes the
precipitate, including arsenic, iron, and any other precipitated constituents. The two-filter module system
operates with the filters in parallel, one filter module is in active operation and one unit is in standby
mode. When backwash of a filter module is required, the standby filter is brought online and the
backwash cycle for the "dirty' filter module is initiated. Once the backwash cycle is complete, the clean
filter module becomes the standby unit.
The KemLoop System is fully automated and programmed to control all aspects of the filter operation.
The control system automatically initiates backwash cycles based on four criteria: differential pressure
across the media filter, treated water turbidity compared to raw water turbidity, time, and volume, as set
by the operator. The backwash frequency is dependent on the water quality conditions and the amount of
solids generated in the coagulation process. The control system is a programmable logic control and
personal computer (PLC/PC) based controller with data logging, trend display graphs, and a remote
monitoring modem connection for off-site technical support. All the information is available to the on-
site operator and to remote users
VERIFICATION TESTING DESCRIPTION
Test Site
The verification test site was the St. Louis Center, a residential community for people with developmental
disabilities, located in Washtenaw County Michigan. The source water was groundwater from two wells
located at this site, which pumped water to a common pressure tank that served as the raw water supply to
the KemLoop System. Water quality data from historical information and the characterization test showed
the wells had similar water quality. Total arsenic in the combined well water ranged from 14 to 32 ug/L
and total iron ranged from 0.39 to 1.6 milligrams per liter (mg/L). The pH was in the 7.4 to 7.6 range with
alkalinity of 250 to 260 mg/L as CaCO3. Raw water turbidity was found to be <1 nephelometric turbidity
unit (MTU) in 2004 and 1.2NTU in the 2005 characterization test.
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Methods and Procedures
Operations, sampling, and analyses were performed in accordance with the Product Specific Test Plan
(PSTP) developed and approved for this verification test. The PSTP included a Quality Assurance Project
Plan (QAPP) designed to assure the quality of the data collected and to provide an accurate evaluation of
the treatment system under the field conditions. Testing included characterization of the raw water, an
arsenic loss test (no chemical fed to the system), and a 14-day verification test.
The verification test was performed from March 23, 2004 through April 6, 2005. The KemLoop System
was operated continuously for the 14-day verification test, independent of the well operations, by using
water supplied from the pressurized supply tank. Flow rate(s), production volume, water temperature, and
system pressure(s) were monitored and recorded daily. Raw, feed (after chlorine and iron addition), and
filtrate (treated) water samples were analyzed on-site for pH, temperature, turbidity, free and total residual
chlorine, color, and dissolved oxygen by the field operator. Grab samples were collected and delivered to
the NSF Drinking Water Laboratory to be analyzed for alkalinity, calcium, magnesium, iron, manganese,
sulfate, chloride, total organic carbon (TOC), total suspended solids (TSS), and fluoride. Samples for
total arsenic were collected daily, plus 14 samples were collected during a 48-hour intensive survey. In
addition to the 25 sets of samples for total arsenic, a total of four sets of arsenic samples were speciated
during the test to determine the soluble arsenic concentration and the concentrations of arsenic (III) and
the arsenic (V) present in the soluble fraction. Samples of backwash water were collected and analyzed to
characterize the backwash wastewater.
Complete descriptions of the verification testing results and quality assurance/quality control (QA/QC)
procedures are included in the verification report.
VERIFICATION OF PERFORMANCE
System Operation
ORCA performed the system startup and shakedown testing, which included optimization of the chemical
feed rates, and determination of backwash frequency. The verification test was conducted under the
manufacturer's specified operating conditions. Chemical feeds were established to feed 1.0 mg/L of total
chlorine. The ferric chloride feed rate was set to deliver 1.5 to 2.5 mg/L (as Fe) of iron to augment the
naturally occurring iron of 0.5 mg/L. The flow rate for filtrate was set at 10 gpm to give a targeted
surface-loading rate of 2940 gallons per day per square foot (gfd). The backwash system was set to
backwash once per day or if the pressure differential across the filter exceeded 8 pounds per square inch
(psi) or if turbidity of the filtrate exceeded the raw water for ten minutes. The backwash cycle used
treated water, which was pumped at 50 gpm through the filter in an up flow mode to flush out 1he
accumulated solids.
System pressure was monitored at three locations, raw water (from pressure tank), feed water (inlet to the
filters), and filtrate (exit from the filters). There was very little change in head loss through the filter over
each 24-hour operating period. The maximum pressure differential observed was 5.0 psi, with the filter
inlet side averaging 5.8 psi and the filter outlet side averaging 2.0 psi. The automatic backwash cycle was
not triggered due to pressure differential (head loss) or an increase in filtrate turbidity at any time during
the verification test.
The filtrate flow rate remained steady for most days during the test yielding an average flow rate of 9.9
gpm over the 14 days. The total filtrate volume produced each day was also consistent, except for April 2
through 4 when volumes and flow rates were somewhat lower. It appears the pressure on the raw water
supply tank at the St. Louis Center was periodically dropping below 40 psi (the setting on the pressure
regulator). This caused periodic lower flow rates and lower volumes of filtrate to be produced over the
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24-hour period. The average hydraulic loading through the filter was 2,890 gallons per square foot, based
on the 24-hour filter run time between backwashes and the average daily filtrate production of 14,630
gallons.
Water Quality Results
The results of total arsenic analyses are shown in Figure VS-1. The raw water total arsenic averaged 23
ug/L with most of the arsenic as arsenic (III). Following chemical treatment, the feed water total arsenic
concentration averaged 22 ug/L. While the soluble arsenic and arsenic speciation data showed some
variability, the data indicate that pretreatment completely converted the raw water arsenic (III) to the
arsenic (V). The filtrate water total arsenic concentration averaged 3 ug/L with the concentration being
below the detection limit (1 ug/L) on six of 14 days. The filtrate exceeded 10 ug/L on the first and last
day of the verification test. On the first day the total arsenic concentration was 12 ug/L with dissolved
arsenic of <1 ug/L. It appears the high arsenic concentration was caused by an overdose of ferric chloride
resulting in solids passing through the filter. After adjusting the iron feed rate, the turbidity in the filtrate
dropped from 1.7 NTU to 0.10 NTU and the arsenic on Day 2 was 1 ug/L. The cause of the higher filtrate
arsenic concentration (11 ug/L) on the last day is not known, as the iron feed rate, and iron concentration
and turbidity level in the filtrate were low. The data collected during the 48-hour intensive survey were
consistent with the data collected each day during the verification test. There was no indication of any
transient or short time changes in the arsenic concentration or in any other monitored parameters.
O)
3
c
01
1/1
ra
'o
35
30
25
20
15
10
5
0
Date
Raw —H Feed
• Filtrate
Note: 48-hour intensive survey began on 3/30/05.
Figure VS-1. Total Arsenic Results
The raw water and filtrate alkalinity averaged 260 mg/L as CaCQj, indicating that the chemical addition
and filtration process had no impact on the alkalinity concentration. The pH of the raw water was steady
in the range of 7.20 to 7.48 with a mean value of 7.30. The filtrate pH ranged from 7.22 to 7.46 with a
median value of 7.30 showing that the addition of chlorine and ferric chloride had very little impact on
pH. The average raw water iron concentration was 0.47 mg/L, and the feed water averaged 1.9 mg/L of
iron after the addition of ferric chloride. The filtrate water iron concentration was 0.03 mg/L or less on ten
out of fourteen days. On March 25 and 31, the iron concentration was 0.08 and 0.07 mg/L, respectively.
The first day of the test, when the iron concentration in the feed was measured at a maximum
concentration of 4.5 mg/L (chemical feed pump subsequently adjusted downward), the filtrate
concentration was 1.7 mg/L. On March 27 the iron was 0.31 mg/L. These data show that the KemLoop
System can produce a filtrate with <0.30 mg/L of iron. The KemLoop System lowered the turbidity levels
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The accompanying notice is an integral part of this verification statement.
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September 2005
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with the filtrate turbidity averaging 0.30 NTU based on the bench-top turbidimeter and 0.20 NTU based
on the inline turbidimeter. The bench top turbidity meter always gave higher turbidity readings compared
to the inline units. The raw water turbidity based on the bench top unit averaged 2.4 NTU, whereas the
average turbidity based on the inline unit was 0.60 NTU. It is believed that the bench top unit data may
have been biased high due to temperature and fogging issues that can be problematic when collecting cold
samples and transferring them to the bench top vials. Based on the bench-top meter measurements, the
filtrate was below 0.5 NTU in 93% of samples, had no values between 0.5 and 1 NTU, and 7% of the
readings (1 reading) were between 1 and 2 NTU. There were no turbidity levels above 2 NTU. The inline
turbidimeter gave the same distribution of turbidity readings in the filtrate. During the 48-hour intensive
survey the turbidity levels in the filtrate did tend to increase slightly near the end of each filter run, and
then were lower again when the standby filter was brought on line. All inline turbidity measurements for
the filtrate during the 48-hour intensive survey were below 0.2 NTU, even at the end of a 24-hour run.
The backwash water was sampled on four occasions and found to have an average total arsenic
concentration of 760 (ig/L, an average iron concentration of 120 mg/L, and an average TSS concentration
of 250 mg/L. The backwash cycle occurred once every 24 hours and yielded an average of 220 gallons
per day of backwash water. This represented 1.5% of the average daily treated water production. The
backwash water was enriched in arsenic, iron, and TSS, as would be expected, given the removal of
arsenic and iron as measured in the filtrate. Local disposal requirements determine whether this water is
acceptable for discharge to a sanitary sewer system, some other discharge location, or if it will require
further treatment prior to discharge. The backwash solids are not considered a hazardous waste based on
Toxicity Characteristic Leaching Procedure (TCLP) arsenic results of 0.32 mg/L, which is below the 5.0
mg/L limit under the Resource Conservation and Recovery Act (RCRA).
Operation and Maintenance Results
The KemLoop System was found to be easy to operate and required little time for daily maintenance. The
field staff was on-site for two to three hours per day. Most of the time on-site was spent performing field
activities, including daily chemical analyses, flow checks, calibrations, etc. In a normal operation, the
inline pH meters and turbidimeters would be used for system checks. The KemLoop System has a
PLC/PC that records data for all key operating parameters, including flow data, pressure information,
backwash cycles, etc. It is estimated that the time to check the system on-site would be minimal, possibly
less than 30 minutes, except when chemical feedstocks needed to be replenished or inline instruments
calibrated. The PLC can be setup for remote access; so main system parameters can be monitored without
a site visit.
The ORCA operation and maintenance (O&M) manual provides a detailed description of the system,
appropriate safety precautions, and detailed descriptions of operating procedures, capability and operation
of the computer control system, and specific instructions for utility operators. The maintenance section of
the manual includes some descriptions of required maintenance, but refers the reader to the individual
equipment literature supplied by the various pump and instrument manufacturers. These manuals were
provided in a notebook. The draft O&M manual did not contain specific checklists for routine site visits.
The review of the O&M manual shows that the manual is well organized and easy to read.
Consumables and Membrane Chemical Cleaning
The KemLoop System used a 6% sodium hypochlorite (bleach) solution, made on site from a 12% stock
solution. A total of 28 liters of 6% bleach solution was used to treat 204,870 gallons of raw water. This
equates to an average concentration added to the raw water of 2.2 mg/L. The average total residual
chlorine in the feed water after chlorine addition was 1.0 mg/L, indicating a chlorine demand in the water
of 1.2 mg/L. Iron was added to the raw water using a 4.8% as iron (Fe) ferric chloride solution. A total of
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23.9 L (6.3 gallons) was used to treat 204,870 gallons of raw water, yielding an average concentration of
iron added to the water of 1.5 mg/L. The feed water concentration averaged 1.9 mg/L and the raw water
concentration averaged 0.47 mg/L, indicating 1.43 mg/L of iron addition, which was close to the
calculated 1.5 mg/L fed based on chemical use.
Electrical power consumption was estimated based on the raw water pump (not used at this site) and
backwash pump horsepower. With miscellaneous electrical use by chemical feed pumps and the PLC/PC,
power consumption is estimated to be 0.5 kilowatt-hr.
Quality Assurance/Quality Control
NSF provided technical and QA oversight of the verification testing as described in the verification
report, including an audit of nearly 100% of the data. The NSF QA department conducted a technical
systems audit during testing to ensure the testing was in compliance with the test plan and performed a
QA review of the analytical data. A complete description of the QA/QC procedures is provided in the
verification report.
Original Signed by Original Signed by
Sally Gutierrez 10/3/05 Robert Ferguson 10/5/05
Sally Gutierrez Date Robert Ferguson Date
Director Vice President
National Risk Management Research Laboratory Water Systems
Office of Research and Development NSF International
United States Environmental Protection Agency
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 April 2002, the verification statement, and the verification report (NSF Report
#04/10/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)
05/20/EPADWCTR The accompanying notice is an integral part of this verification statement. September 2005
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September 2005
Environmental Technology Verification Report
Removal of Arsenic in Drinking Water
ORCA Water Technologies
KemLoop 1000 Coagulation and Filtration
Water Treatment System
Prepared for:
NSF International
Ann Arbor, Michigan 48105
Prepared by:
NSF International
And
Scherger Associates
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.
Sally Gutierrez, Director
National Risk Management Research Laboratory
in
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Table of Contents
Verification Statement VS-i
Notice ii
Foreword iii
Table of Contents iv
Abbreviations and Acronyms viii
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 Site Background Information 4
1.3.2 Source/Feed Water Quality 5
1.3.3 Test Site Description 6
Chapter 2 Equipment Capabilities and Description 8
2.1 Description of Equipment 8
2.2 Engineering and Scientific Concepts 8
2.3 Description of Treatment Train and Unit Processes 9
2.4 Description of Physical Construction and Components 12
2.5 Chemical Consumption and Production of Waste Material 13
2.5.1 Chemical Consumption 13
2.5.2 Waste Production and Physical and Chemical Nature of Wastes 13
2.6 Licensing Requirements 13
2.7 Statement of Performance Objectives 14
2.8 Advantages of the ORCAKemLoop Process 14
2.9 Potential Limitations of the Equipment 14
Chapter 3 Methods and Procedures 15
3.1 Quantitative and Qualitative Evaluation Criteria 15
3.2 Key Water Quality Parameters 15
3.2.1 KemLoop System Water Quality Operating Range 15
3.2.2 Key Water Quality Parameters for Evaluating Equipment Performance 16
3.3 Definition of Operational Parameters 16
3.4 Operations and Maintenance 17
3.5 Field Operations Procedures 17
3.6 Environmental Technology Verification Testing Plan 17
3.6.1 Task A: Raw Water Characterization 18
3.6.2 TaskB: Initial Test Runs 18
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3.6.3 Task C: Verification Test Procedures 18
3.7 Task A: Raw Water Characterization 19
3.7.1 Site Background Information 19
3.7.2 Additional Analytical Data 19
3.7.3 Evaluation Criteria 20
3.8 TaskB: Initial Test Runs 20
3.8.1 Objectives 20
3.8.2 Work Plan 20
3.8.3 Arsenic Loss Test 20
3.8.4 Analytical Schedule 21
3.8.5 Evaluation Criteria 21
3.9 TaskC: Verification Test 22
3.9.1 Introduction 22
3.9.2 Experimental Objectives 22
3.9.3 Task 1: Verification Testing Runs 22
3.9.4 Task 2: Raw Water, Feed Water, and Filtrate Water Quality 25
3.9.5 Task 3: Operating Conditions and Treatment Equipment Performance 30
3.9.6 Task 4: Arsenic Removal 32
3.9.7 Task 5: Data Management 34
3.9.8 Task 6: Quality Assurance/Quality Control 36
3.10 Operation and Maintenance 37
3.10.1 Maintenance 37
3.10.2 Operation 38
3.10.3 Operability Evaluation 39
Chapter 4 Results and Discussion 41
4.1 Introduction 41
4.2 Equipment Installation, Startup, and Shakedown 41
4.3 Task A: Raw Water Characterization 42
4.4 TaskB: Initial Test Runs 43
4.4.1 Arsenic Loss Test 43
4.5 TaskC: Verification Test 46
4.5.1 Operating Results 46
4.5.2 Arsenic Results 48
4.5.3 Raw, Feed, and Filtrate Water Quality Results 54
4.5.4 Backwash Water Frequency and Quality 69
4.5.5 Chemical Consumption and Electrical Use 70
4.6 Other Operating Information 71
4.7 Quality Assurance/Quality Control 75
4.7.1 Documentation 75
4.7.2 Quality Audits 75
4.7.3 Data Quality Indicators 76
Chapter 5 References 83
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List of Figures
Figure 2-1. KemLoop System Front and Side View 11
Figure 2-2. KemLoop System Skid Mounted Unit Photograph 12
Figure 4-1. Verification Test Daily Arsenic Results 53
Figure 4-2. Verification Test pH Results 56
Figure 4-3. Verification Test Turbidity Results 60
Figure 4-4. Verification Test Alkalinity Results 62
Figure 4-5. Verification Test Iron Results 64
List of Tables
Table 1-1. Historical Raw Water Quality Data 5
Table 1-2. Raw Water Quality Data-2004 6
Table 2-1. Test System Expected Operating Conditions 10
Table 2-2. KemLoop System Specifications 11
Table 3-1. Quantitative and Qualitative Evaluation Criteria 15
Table 3-2. Operating Range of the KemLoop System 16
Table 3-3. Key Filtrate Water Quality Parameters 16
Table 3-4. Water Quality Parameters for Raw Water Characterization 20
Table 3-5. Water Quality Parameters - Arsenic Loss Test 21
Table 3-6. On-site Equipment Operating and Monitoring Data Schedule 24
Table 3-7. Sampling Schedule 26
Table 3-8. Analytical Methods 27
Table 3-9. Sample Bottles, Preservation, and Holding Time 28
Table 3-10. Parameter List for the 48-Hour Intensive Survey 34
Table 4-1. Raw Water Characterization Data - February 24 and March 9,2005 43
Table 4-2. Arsenic Loss Test Operating Data 44
Table 4-3. Arsenic Loss Test Water Quality Results 45
Table 4-4. Arsenic Loss Test Daily Water Quality Results 46
Table 4-5. Operating Data 48
Table 4-6. Daily Total Arsenic Results (|ig/L) 50
Table 4-7 Total Arsenic Results for the 48-Hour Intensive Survey (|ig/L) 51
Table 4-8. Arsenic Speciation Data (|ig/L) 52
Table 4-9. pH Results (S.U.) 54
Table 4-10. pH Results (bench top) for the 48-Hour Intensive Survey (S.U.) 55
Table 4-11. Turbidity Results (NTU) 58
Table 4-12. Inline Turbidity Results for the 48-Hour Intensive Survey (NTU) 59
Table 4-13. Alkalinity Results for the 48-Hour Intensive Survey (mg/L as CaCO3) 63
Table 4-14. Iron Results for the 48-Hour Intensive Survey (mg/L) 65
Table 4-15. Total and Free Residual Chlorine (mg/L) 66
Table 4-16. Free and Total Residual Chlorine Results for 48-Hour Survey (mg/L) 67
Table 4-17. Other Water Quality Parameters 68
Table 4-18. Backwash Water-Water Quality Results 70
Table 4-19. Backwash Solids - TCLP and CAWET Analyses 70
VI
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Table 4-20. Field Instrument Calibration Schedule 77
Table 4-21. Filtrate Flow Meter Calibration Data 77
Table 4-22. Precision Data - Field Duplicates for Laboratory Parameters 80
Table 4-23. Precision Data - Field Duplicates for Field Parameters 81
Table 4-24. Completeness Results 82
Appendices
Appendix A - Operation and Maintenance Manual
Appendix B - Field Logbooks, Field Log Sheets, Field Calibration Records, PLC Readout
Appendix C - NSF Laboratory Data Reports and Sample Chain of Custody Forms
Appendix D - Spreadsheets
Appendix E - TriMatrix Laboratories Data Report for TCLP and CAWET Analyses
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Abbreviations and Acronyms
BOD
CaCO3
CAWET
°C
c.u.
Center
°F
DO
DWS
DWTS
EPA
ETV
FeCl3
ft2
ft3
FRP
FTO
g
gfd
gpm
gpd
hp
hr
KemLoop
L
LCS
m
MCL
mL
mg
mg/L
ND
NIST
NRMRL
NSF
NTU
O&M
ORCA
PLC/PC
psi
PSTP
QA/QC
QAPP
RCRA
Biochemical Oxygen Demand
Calcium Carbonate
California Waste Extraction Test
Degree Celsius
Color Units
St. Louis Center
Degree Fahrenheit
Dissolved Oxygen
Drinking Water Systems
NSF International Drinking Water Treatment Systems Laboratory
Environmental Protection Agency
Environmental Technology Verification
Ferric Chloride
Square Feet or Square Foot
Cubic Feet
Fiber-reinforced Polymer
Field Testing Organization
Gram
Gallons per Square Foot per Day
Gallon(s) Per Minute
Gallon(s) Per Day
Horsepower
Hour(s)
KemLoop 1000 Coagulation and Filtration Water Treatment System
Liter
Laboratory Control Sample
Meter
Maximum Contaminant Level (USEPA standard)
Milliliter
Milligram
Milligram per Liter
Not Detected or Non-Detect
National Institute of Standards and Technology
National Risk Management Research Laboratory
NSF International
Nephelometric Turbidity Unit(s)
Operation and Maintenance
ORCA Water Technologies
Programmable Logic Controller/Personal Computer
Pounds per Square Inch
Product Specific Test Plan
Quality Assurance/Quality Control
Quality Assurance Project Plan
Resource Conservation and Recovery Act
vin
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RSD Relative Standard Deviation
SMCL Secondary Maximum Contaminant Level
S.U. Standard Units
TCLP Toxicity Characteristic Leaching Procedure
IDS Total Dissolved Solids
TOC Total Organic Carbon
TSS Total Suspended Solids
|ig/L Microgram(s) per Liter
VAC Volts Alternating Current
IX
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Acknowledge ments
The Field Testing Organization (FTO), NSF International (NSF) Drinking Water Treatment
Systems Laboratory (DWTS) and its consultant, Scherger Associates, was responsible for all
elements in the testing sequence, including collection of samples, calibration and check of
instrumentation, data collection and analysis, data management, data interpretation, and the
preparation of this report.
NSF International Drinking Water Treatment Systems Laboratory
789 N. Dixboro Road
Ann Arbor, Michigan 48105
Contact Person: Rob Herman
Scherger Associates
3017 Rumsey Drive
Ann Arbor, Michigan 48105
Contact Person: Dale Scherger, P.E.
The laboratory selected for the analytical work for this test was:
NSF International Chemistry Laboratory
789 N. Dixboro Road
Ann Arbor, Michigan 48105
Contact Person: Kurt Kneen
The manufacturer of the equipment was:
ORCA Water Technologies
1879 Portola Road, Suite E
Ventura, California 93003
Contact Person: John Crass
The NSF DWTS wishes to thank the following participants:
Mr. Bruce Bartley, Ms. Angela Beach, and Mr. Michael Blumenstein of the NSF Environmental
Technology Verification (ETV) Drinking Water Systems (DWS) Center for their support,
guidance, and program management.
The St. Louis Center staff, especially Mr. William Potter, for help during the initial site selection
and water quality review process, and Mr. Randy Hoenes, who provided invaluable field support
to ORCA and NSF by arranging all site installation requirements and providing mechanical and
electrical utilities support for the test system throughout the installation, startup, and testing
program.
ORCA Water Technologies for supplying the verification test unit and support services during
the start-up period. Mr. John Crass coordinated building and shipping of the test unit. Ronald
Tenny's presence at the site to optimize the operation of the system and provide training to the
NSF field operators is greatly appreciated.
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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 DWS Center evaluated the performance of the ORCA Water Technologies (ORCA)
KemLoop 1000 Coagulation and Filtration Water Treatment System (KemLoop System), which
is a granular media filtration system used in drinking water treatment system applications for
reduction of arsenic and dissolved iron in groundwater. This document provides the verification
test results for the KemLoop System.
1.2 Testing Participants and Responsibilities
The ETV testing of the KemLoop System was a cooperative effort among the following
participants:
NSF International
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NSF International Drinking Water Treatment Systems Laboratory (DWTS) and its
consultant, Scherger Associates
ORCA Water Technologies
The St. Louis Center
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 and 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, Michigan 48105
Contact: Bruce Bartley, Project Manager
Phone: (734) 769-8010
Fax: (734) 769-0109
Email: bartley@nsf.org
1.2.2 Field Testing Organization
The DWTS conducted the verification testing of the KemLoop System. The DWTS is an NSF-
qualified FTO for the ETV DWS Center.
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 and its consultant, Scherger Associates, 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. The FTO was
responsible for completing the raw water characterization testing, monitoring the KemLoop
System during the arsenic loss testing (24 hour test), and conducting the verification test over 14
calendar days.
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DWTS employees conducted the on-site analyses and data recording during the test. The FTO's
Project Manager and Project Director provided oversight of the daily tests.
Contact Information:
NSF International Drinking Water Treatment Systems Laboratory
789 N. Dixboro Road
Ann Arbor, Michigan 48105
Contact Person: Rob Herman
Phone: (734) 769-5349
Fax: (734) 827-7143
Email: herman@nsf.org
Scherger Associates
3017 Rumsey Drive
Ann Arbor, Michigan 48105
Contact Person: Dale Scherger, P.E.
Phone: (734)213-8150
Fax: (734)213-8150
Email: daleres@aol.com
1.2.3 Manufacturer
The treatment system was the ORCA KemLoop 1000 Coagulation and Filtration Water
Treatment System for the treatment of drinking water. The manufacturer was responsible for
supplying a field-ready coagulation and filtration 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:
ORCA Water Technologies
1879 Portola Road, Suite E
Ventura, California 93003
Contact Person: Mr. John Crass
Phone: (805) 639-3071
Fax: (805) 639-3072
Email: icrass@orcawt.com
1.2.4 Analytical Laboratory
The NSF International Chemistry Laboratory in Ann Arbor, Michigan performed all water
quality analyses.
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Contact Information:
NSF International Chemistry Laboratory
789 N. Dixboro Road
Ann Arbor, Michigan 48105
Contact Person: Kurt Kneen
Phone: (734) 827-6874
Fax: (734) 827-7765
Email: kneen@nsf.org
Backwash toxicity analyses were performed by:
Contact Information:
TriMatrix Laboratories, Inc.
5555 Glenwood Hills Parkway, SE
Grand Rapids, Michigan 49588
Phone: (810)220-2075
Fax: (810) 220-2803
Contact: Michael W. Movinski, Vice President, Sales and Marketing
Email: mmtrimatrix@comcast.net
1.2.5 U.S. Environmental Protection Agencj
The EPA, through its Office of Research and Development, has financially supported and
collaborated with NSF under Cooperative Agreement No. R82833301. 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
1.3.1 Site Background Information
The St. Louis Center (Center), located at 16195 Old US 12, Chelsea, Michigan, is a residential
community for people with developmental disabilities. Founded by the Archdiocese of Detroit
and operated by the Servants of Charity, the Center has been in continuous operation since it was
first established as a boarding school in 1960. Sleeping quarters and additional facilities were
completed in 1984 and 1988 to expand its ability to care for adults functioning at different levels.
The 180-acre site includes the main building with administrative offices, central kitchen and
dining facilities, gymnasium, chapel, and residential facilities. Father Guanella Hall and St.
Joseph Hall are freestanding residential buildings with complete kitchen and laundry facilities for
the residents. In addition, there are separate facilities for guests and outdoor recreation activities.
The Center is currently licensed for 73 residents.
Two groundwater production wells are installed at the Center to supply potable water. The
wells, a pressurized water supply tank, boilers, and related equipment are housed in a separate
building. The building has the necessary space and utilities to support the KemLoop System.
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Both wells and a single pressurized water supply tank are used to deliver water to the Center.
The water supply tank is a fixed wall tank with no bladder insert. When the water in the supply
tank drops to a preset level, one well is activated to refill the tank. Once the tank is filled, the
pump shuts off. When the water level drops again, the second pump turns on to refill the tank.
This alternating cycle is the standard operating mode for the system. Therefore, the raw water
taken from the supply tank for the verification test is a blend of the two wells. There are no
chemicals added to the well water pumped to the supply tank or to the water delivered to the
Center.
The average daily water use for the school is approximately 6,600 gallons per day (gpd) based on
weekly meter readings. The average maximum water use based on the weekly readings is
12,000 gpd. Well #1 typically reaches a maximum pumping rate of approximately 145 gallons
per minute (gpm), whereas Well #2 typically reaches a maximum pumping rate of approximately
125 gpm. Observation of the wells shows that Well #1 normally pumps for 4-5 minutes and
Well #2 normally pumps for 5-6 minutes to refill the supply tank. The supply tank is replenished
based on level control, and the time between pump activation depends on the demand for water.
On average, a well pump is actively pumping (either #1 or #2) for approximately 5-6 minutes
every 1-2 hours. Run time varies widely depending on demand, with greater demand in the
morning and daytime, and less at night.
1.3.2 Source/Feed Water Quality
Tables 1-1 and 1-2 present raw water quality for samples taken from the individual wells and
combined water from the supply tank. The St. Louis Center collected the historical data as part
of a monitoring program from 1998-2003. NSF collected and analyzed samples in March and
May 2004, when the site was evaluated as a potential test site. The water has total hardness of
240-350 milligrams per liter (mg/L) as calcium carbonate (CaCOs), and the pH is normally about
7.6. Water quality data for total arsenic are available for the period between December 1998 and
May 2004. These data show that total arsenic concentration varies between 14 and 48
micrograms per liter (|ig/L). The predominate arsenic species is arsenic (III).
Table 1-1. Historical Raw Water Quality Data
Parameter Units Pressure Tank Water Supply
Combined Wells 1 and 2
Total Arsenic
Hardness
Sodium
Chloride
Sulfate
Fluoride
Iron
Nitrite
Nitrate
Selenium
H8/L
mg/L as
CaCO3
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
H8/L
Dec.
1998
15
—
—
—
—
—
—
—
<5
Nov.
2000
32
—
—
—
—
—
—
—
1
Feb.
2001
26
—
—
—
—
—
—
—
—
June
2001
23
—
—
—
—
—
—
—
—
June
2002
—
352
12
33
21
0.7
0.5
O.05
<0.4
—
July
2003
—
328
15
23
24
0.8
0.4
O.05
<0.4
—
Jan.
2003
14
—
—
—
—
—
—
—
<1
"—" = Not required or scheduled for analysis.
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Table 1-2. Raw Water Quality Data - 2004
Parameter
Total As
Soluble As
Arsenic (III)
Arsenic (V)
(calculated)
PH
Hardness
Alkalinity
Total Dissolved
Solids (TDS)
Chloride
Sulfate
Fluoride
Iron
Phosphate
Manganese
Molybdenum
Selenium
Vanadium
Silica
Total
Suspended
Solids (TSS)
Units
ug/L
ug/L
ug/L
s/L
S.U.
mg/L as
CaCO3
mg/L as
CaCO3
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
ug/L
ug/L
ug/L
ug/L
mg/L
mg/L
Well
March
2004
25
—
—
7.56
270
260
300
—
21
—
0.36
—
16
—
—
—
—
2
#1
May
2004
30
27
28
<2
—
—
—
6.3
29
0.4
1.6
0.98
15
10
<4
<1
16.6
2
Well
March
2004
48
—
—
7.66
240
260
300
—
10
—
2.8
—
20
—
—
—
—
8
#2
May 2004
34
38
37
<2
—
—
—
16
8
0.9
2.8
0.84
15
21
<4
<1
18.6
6
Pressure Tank Water
Supply - Combined
Wells 1 and 2
March
2004
24
—
—
7.64
280
260
340
—
21
—
0.50
—
14
—
—
—
—
<2
May 2004
31
—
—
—
—
—
—
—
—
1.6
—
18
—
—
—
—
—
"—" = Not required or scheduled for analysis.
1.3.3 Test Site Description
Structural
The entire water supply system, two wells, supply tank, controls, and piping were located inside
a secure building. There was room in the building to add the needed piping to supply the test
unit, and to store basic supplies and equipment needed by the FTO. The KemLoop System was
housed in an insulated, 8 X 20 foot shipping container that had heaters to prevent freezing during
the test. The containerized system was located immediately adjacent to the water supply
building. The water supply from the pressurized main system storage tank was piped to the
treatment unit. This test site provided the following advantages:
• Full electrical supply;
• Building to enclose the wells and pressure holding tank;
• Ease of accessibility; and
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• All required utilities, including raw water supply, power, and drain locations for the
discharge of the filtrate and backwash water to the on-site sewer system and wastewater
treatment lagoon.
Handling of Filtrate and Residuals
All treated water (filtrate) was discharged to a sewer that discharges to the wastewater treatment
lagoon. Backwash water was collected in a holding tank where solids settled to the bottom. The
overflow from the backwash tank discharged at the same location as the treated water. The
backwash water holding tank was discharged manually each day by the DWTS field personnel.
Discharge Permits
No special discharge permits were required for the discharge of the filtrate and backwash water
from the test unit to the on-site wastewater treatment system.
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Chapter 2
Equipment Capabilities and Description
2.1 Description of Equipment
The KemLoop System used during the verification was a standard, full-scale system supplied by
ORCA for the treatment of groundwater. The KemLoop System is a self-contained, complete
system that can connect to either a pressurized water supply (35-75 pounds per square inch [psi])
or to a non-pressurized supply source. If the source is not pressurized, a pump, supplied with the
unit, can be used to pump the water through the treatment system. For this test, the filtrate was
discharged to the Center's sewer system and ultimately entered the wastewater lagoon. In a
normal installation, the treated water (filtrate) would be collected in a tank and pumped to the
pressurized potable water distribution system. The KemLoop System used for the verification
test was designed to treat flows at an average of 10 gpm with a maximum capacity of 20 gpm.
Additional information on the equipment installation requirements and operation of the
equipment is provided in the O&M Manual, presented in Appendix A.
The KemLoop System is fully automated and programmed to control all aspects of the filter
operation. The control system automatically initiates backwash cycles based on four criteria:
differential pressure across the media filter, treated water turbidity compared to raw water
turbidity, time, and volume, as set by the operator. The backwash frequency is dependent on the
water quality conditions and the amount of solids generated in the coagulation process. The
control system is a programmable logic control and personal computer (PLC/PC) based
controller with data logging, trend display graphs, and a remote monitoring modem connection
for off-site technical support. The PLC/PC monitors and records data from the system operation.
All the information is available to the on-site operator and to remote users.
2.2 Engineering and Scientific Concepts
Coagulation and precipitation of arsenic using iron as a coagulant is a well-known basic
technology for arsenic removal. Various forms of iron (e.g., ferric chloride) are added to water,
and the pH is adjusted to an optimal level to form iron floe. As part of the coagulation process,
arsenic is co-precipitated with the iron. The mixing process helps to build the floe into larger
particles that can be removed by various techniques (settling, filtration, etc.). Some treatment
systems use flocculation tanks and clarifiers with or without post filtration to remove the
precipitated iron and arsenic particulate. Other process trains use only chemical coagulation,
mixing, and media filtration. The KemLoop System is based on chemical coagulation, a
proprietary mixing loop to optimize the coagulation process, and granular media filtration with
no intermediate solids separation process.
It is widely accepted in the scientific community that the precipitation of arsenic (V) with iron or
similar coagulants is readily achieved and that settling or filtration can remove the precipitate.
Arsenic (III), however, is not removed as easily to the low concentrations required to meet
drinking water regulations. Water that contains arsenic (III) is often pre-treated with an
oxidization step to convert the arsenic (III) to arsenic (V). Water quality data collected in 2004
show that arsenic (III) is the dominant form of arsenic in the groundwater at the Center, even
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after storage in the pressurized supply tank. The KemLoop System uses chlorine (fed as sodium
hypochlorite) as a pretreatment step to convert arsenic (III) to arsenic (V).
2.3 Description of Treatment Train and Unit Processes
The KemLoop System includes pretreatment with liquid sodium hypochlorite to oxidize any
arsenic (III) to arsenic (V), and to oxidize the iron present in the water supply. The sodium
hypochlorite is pumped into the inlet line by a chemical metering pump. Total residual chlorine
is targeted to a range of 0.5-1.0 mg/L. Ferric chloride (FeCfe) is added to augment the naturally
occurring iron in the groundwater and optimize the iron dose. The typical target range is 1.5-3.0
mg/L as iron. The actual dose is optimized during start-up/shakedown testing. The system can
also include addition of sulfuric acid, if needed to adjust the pH to an optimal level, as
determined during shakedown testing at the site; pH adjustment was not required for the test site
raw water. This chemically treated water (feed water) enters the "mixing loop," a unique feature
of the KemLoop System. This mixing loop consists of approximately 200 feet of 3 inch PVC
pipe and includes a recirculation line.
The chemically treated water flows through the mixing loop, where precipitation and coagulation
of the iron and arsenic occur without the need for a separate mixing tank. The coagulated water
exits the mixing bop and is applied directly to one of the two granular media filter modules.
The water enters the top of the operating filter and flows through the granular media filter,
exiting at the bottom of the module. The granular media filter removes the precipitate, including
arsenic, iron, and any other precipitated constituents. The two-filter module system operates
with the filters in parallel; one filter module is in active operation and one unit is in standby
mode. When backwash of a filter module is required, the standby filter is brought online and the
backwash cycle for the "dirty" filter module is initiated. Once the backwash cycle is complete,
the clean filter module becomes the standby unit.
The backwash cycle is triggered by an increase in differential pressure across the operating filter
module or by an increase in turbidity in the filtered water. The backwash cycle can also be
activated by time of operation or volume of water treated, as set by the operator. The differential
pressure and turbidity levels that trigger a backwash cycle are set during the shakedown and
start-up test period based on local requirements and operating characteristics at the site. The
time cycle, based on experience at a site, is typically set to ensure that at a filter module is
backwashed at least once every two days. The backwash cycle uses raw water or filtrate for the
backwash water source. Backwash is accomplished by pumping raw or filtrate water at a rate of
75-100 gpm (15-20 gpm per square foot of filter surface area) through the filter module in an up
flow mode, expanding the granular media bed, and flushing the solids from the media.
Approximately 500 gallons of water are used for each five-minute backwash cycle. Backwash
water is normally collected in a tank to allow sampling of the water and for treatment, if
required. The water is then discharged to the on-site wastewater treatment system, local sanitary
sewer system, or other approved discharge location.
For the ETV test, the raw water was obtained from the pressure tank at the site (both wells feed
the tank on an alternating cycle basis), which normally operates at 55-90 psi. A pressure
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regulator, set at 40 psi, and a flow control valve were installed downstream of a double backflow
preventer to control the flow rate of raw water to the system.
Chemical feed ports located in the inlet piping of the KemLoop System provide for injection of
sodium hypochlorite, ferric chloride or other iron source, and acid, if needed. Acid for pH
adjustment was not needed for the Center water. Chemical metering pumps were used to inject
sodium hypochlorite and ferric chloride into the water. The liquid sodium hypochlorite was
stored in a 5-gallon plastic container, and the ferric chloride was stored in a 15-gallon plastic
container.
Sampling ports were installed before any chemical addition (raw water) and after the chemical
addition points and after mixing occurred, near the inlet to the filter module (feed water). These
sampling ports were valves placed in the line for collection of the samples of the raw water and
the feed water to the filter module. A third sampling valve was installed on the treated water
(filtrate) line downstream of the filters. This sampling valve was used to collect filtrate water
samples.
The KemLoop System had two inline turbidimeters to monitor turbidity on a continuous basis.
Turbidity was monitored and recorded for the raw water and the filtrate. The KemLoop System
also had an inline total residual chlorine analyzer installed on the filtrate line.
A summary of the expected operating conditions, provided by ORCA, is presented in Table 2-1.
The actual operating conditions during the verification test were close to the expected conditions
and are described in Chapter 4.
Table 2-1. Test System Expected Operating Conditions
Parameter Specification
Filtrate flow rate 10 gpm
Filter loading rate 2940 gallons per square foot per day (gfd)
Backwash flow rate 75-100 gpm
Backwash water per cycle 500 gallons
Pressure differential for backwash initiation 8 psi
Turbidity level in filtrate for backwash initiation When filtrate is higher than raw water for
10 minutes
Feed water pressure 35-75 psi
Source water pressure 55-90 psi
The granular media filter material used for the verification test was a standard mix of sand,
gravel, and garnet purchased locally. Specifications for the KemLoop System and granular
media are given in Table 2-2. Figures 2-1 and 2-2 show a schematic and photograph of a typical
system.
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Table 2-2. KemLoop System Specifications
Name
Model
Filter Module Surface Area
Filter Module Volume (approx
without dome)
Media Depth
Number of Filter Modules
Filter Pressure Rating
Mixed Media Per Filter Module
Skid
Piping
ORCA KemLoop 1000
Coagulation and Filtration Water Treatment System
1000
4.9ft2
20ft3
32 inches
2 - Steel tanks lined with NSF certified epoxy coating
75 psi max operating pressure
(1) 200 pounds course gravel; 4 inches deep;
1/4 X 3/8 gravel; uniformity coefficient 1.4
(2) 250 pounds fine gravel; 5 inches deep;
1/4 X 1/8 gravel; uniformity coefficient 1.4
(3) 250 pounds course garnet; 4.5 inches deep
8 X 12 coarse garnet; uniformity coefficient 1.37
(4) 200 pounds fine garnet; 3.5 inches deep;
30 X 40 mesh; uniformity coefficient 1.22
(5) 600 pounds #30 sand; 15 inches deep;
uniformity coefficient <1.6
(6) 50 pounds of anthracite; 2 inches deep;
0.80-0.95 mm; uniformity coefficient 1.32
6 inch steel with 1.5 inch FRP grating
(Note: Unit was an 8 X 20 ft shipping container for this test.)
Schedule 80 PVC
Figure 2-1. KemLoop System front and side view.
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Figure 2-2. KemLoop System skid mounted unit photograph.
2.4 Description of Physical Construction and Components
The KemLoop System is a skid mounted, self-contained unit that weighs between 5,000 and
7,000 pounds. The granular media filter modules are steel tanks with inlet flow distributors,
media support plates, and associated fittings, valves, and piping. Maximum operating pressure is
approximately 75 psi. The standard unit is 14 ft (L) X 8 ft (W) X 8.75 ft (H). The main
components of the unit are:
• 1.5 horsepower (hp) feed centrifugal pump (supplied but not used in this test);
• 1.5 hp backwash centrifugal pump;
• Two chemical metering pumps;
• One inline solid contact chlorinator (supplied but not used in this test);
• Schedule 80 PVC piping for water;
• Two filter modules;
• Two pressure transmitters;
• Three flow meters;
• Two inline pH meters;
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• Two inline turbidimeters;
• Automated PLC/PC based control system; and
• One Hach 9184 Free Chlorine Analyzer.
Additional specifications and information are provided in Appendix A.
For the verification test, the equipment was constructed in a standard shipping container rather
than using a skid mount design because the building at the Center was not large enough to
enclose the skid-mounted unit. The shipping container protected the unit from Michigan winter
weather and provided a heated environment. All equipment used in the containerized system
was identical to the equipment used for the standard skid mounted unit.
2.5 Chemical Consumption and Production of Waste Material
2.5.1 Chemical Consumption
Two chemicals were used during the operation of the treatment system: sodium hypochlorite and
ferric chloride. Sodium hypochlorite was fed to oxidize arsenic (III) to arsenic (V) and the
naturally occurring iron in the raw water. A concentration of approximately 1.0 mg/L of total
residual chlorine was shown to be sufficient during the shakedown period. Ferric chloride was
added for arsenic removal by coagulation. The final feed rate for ferric chloride based on
shakedown testing was determined to be 1.5-2.5 mg/L as iron. The raw water averaged
approximately 0.5 mg/L, giving a target iron concentration in the feed water of 2.0-3.0 mg/L.
Chemical use was monitored during the test, and storage containers were replenished as needed.
2.5.2 Waste Production and Physical and Chemical Nature of Wastes
Backwash water containing the solids (iron and arsenic) generated during the coagulation and
precipitation process was expected to result in approximately 500 gallons per backwash cycle. It
was anticipated that one or possibly two backwashes would occur per day during continuous
operation, generating 500-1000 gallons per day of backwash water. The actual backwash
generated was approximately 250 gallons per backwash. Actual backwash frequency was once
per day on a time basis; pressure drop and turbidity did not trigger any additional backwashes
during the verification test. For the verification test system, the backwash water was discharged
to a holding tank, which was then manually discharged to the on-site wastewater system. No
special permits were required for this discharge for the verification test.
At some permanent installations, the backwash water may need to be sent to a sanitary sewer
system or a liquid-solids separation process may be required to clean the backwash water prior to
discharge or return to the raw water feed. If solids are settled or filtered, they will contain higher
levels of iron and arsenic and may require special handling for disposal.
2.6 Licensing Requirements
There were no special licensing requirements to operate the KemLoop System during the ETV
test since the treated water was discharged to the sewer system and not used as a potable water
supply.
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2.7 Statement of Performance Objectives
The ORCA KemLoop 1000 Coagulation and Filtration Water Treatment System is a granular
media filtration system used in drinking water treatment system applications for removal of
arsenic and dissolved iron from groundwater. This document provides the actual verification test
results for the KemLoop System.
2.8 Advantages of the ORCA KemLoop Process
According to ORCA, the main advantages of the KemLoop process for removing arsenic from
water are as follows:
• The process is simple and compact;
• The granular filtration system is a standard filtration technology;
• Fully automated control system allows operation with only periodic operator attention;
• Unique mixing loop eliminates the need for large mixing tanks, coagulation tanks, and
clarifiers or settling basins;
• System is compatible with chlorine and other common treatment chemicals; and,
• Modular construction on skids provides for ease of installation and expansion.
2.9 Potential Limitations of the Equipment
The KemLoop process for the treatment of raw drinking water with respect to source water
quality has the following potential limitations.
• Poor source water quality can cause high solids loadings to the filter, increasing
backwash frequency and quantity of solids generated.
• A disposal location, such as a settling basin, on-site wastewater treatment plant, or a
sanitary sewer system, is needed to handle the backwash water generated on a daily basis.
• While the system is automated and operation should be easy, a moderate level of operator
skill maybe required for successful use of the system. Variable source water quality may
require adjustment of the chemical feeds in order to maintain optimal removal efficiency.
• A heated structure is recommended when freezing temperatures are encountered.
• Routine maintenance includes brief visual inspection to check pumps, pipes, fittings, and
valves for leaks. Inline pH and turbidimeters require calibration. Chemicals need
replenishment to ensure adequate supplies are available for injection into the system.
14
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Chapter 3
Methods and Procedures
3.1 Quantitative and Qualitative Evaluation Criteria
As defined in the ETV protocol, the objectives of the verification test are to evaluate equipment
in the following areas:
• The actual results obtained by the equipment as operated under the conditions at the test
site;
• The impacts on performance of any variations in feed water quality or process variation;
• The logistical, human, and other resources necessary to operate the equipment; and
• The reliability, ruggedness, ranges of usefulness, and ease of operation of the equipment.
To address these objectives, the verification test employed the quantitative and qualitative factors
listed in Table 3-1 in evaluating the KemLoop System performance.
Table 3-1. Quantitative and Qualitative Evaluation Criteria
Quantitative Factors
Qualitative Factors
Feed water flow rate
Treated water quality
Length of operating cycle
Frequency of backwash cycles
Power consumption
Chemical use
Maintenance requirements
Required level of operator attention
Spatial requirements
Discharge requirements
Waste disposal
Ease of operation
Safety
Susceptibility to environmental conditions
Impact of operator experience on successful
operation
The primary applications of the KemLoop System are the removal of dissolved inorganic
chemicals that can be precipitated by chemical addition. In the case of this verification, the
primary application was total arsenic removal.
3.2 Key Water Quality Parameters
3.2.1 KemLoop System Water Quality Operating Range
The operating range of the KemLoop System as specified by ORCA is summarized in Table 3-2.
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Table 3-2. Operating Range of the KemLoop System
Parameter Range
Total arsenic Less than 200 ug/L w
pH 5-10 S.U.
Turbidity 0-1000NTU(2)
^' During verification testing, the range of total arsenic in the feed water was 19-27 (ig/L.
^ During verification testing, low turbidity groundwater was tested (0.70-6.8 nephelometric turbidity units
[NTUs]).
3.2.2 Key Water Quality Parameters for Evaluating Equipment Performance
Key water quality parameters used for evaluation of the KemLoop System are listed in Table 3-
3. The Water Quality and Inorganic Parameter columns are the key parameters for evaluating
the treatment process and water quality. The Other Parameters should not have an immediate
impact on the treatment process, but are important parameters in drinking water supplies.
Table 3-3. Key Filtrate Water Quality Parameters
Water Quality Inorganic Parameters Other Parameters
• Temperature • Arsenic • Manganese
• Alkalinity • Iron • True Color
• Hardness • TSS (backwash water) • Total Organic Carbon (TOC)
• pH • Chloride
• Turbidity • Sulfate
• Residual Chlorine • Fluoride
• Dissolved Oxygen
3.3 Definition of Operational Parameters
The following are definitions used in this report and for designation of sampling locations:
Filtrate is defined as the water produced by the granular media filtration process, the treated
water.
Feed water is defined as the water introduced to the granular media filter after all chemical
additions.
Raw water is the source water supply. In this test, the raw water is the water supplied from the
pressurized supply tank.
Differential pressure is the pressure across the granular media filtration module, equal to the feed
water pressure at the inlet to the filter minus the filtrate pressure at the outlet of the filter module:
DP=Pf-P0 (3-1)
Where: DP = differential pressure (psi, bar)
Pf = inlet pressure to the feed side of the filter (psi, bar)
16
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P0 = outlet pressure on the discharge side of the filter (psi, bar)
3.4 Operations and Maintenance
ORCA provided a draft O&M manual with the KemLoop System, which is included in
Appendix A. As part of the verification testing, the ETV DWS Center reviewed the O&M
documentation for the KemLoop System. Results of the review are included in this ETV report.
In addition, the following aspects of operability are addressed in the report:
• Fluctuation of flow rates and pressures through unit (the time interval at which resetting
is needed);
• Presence of devices to aid the operator with flow control adjustment;
• Availability of pressure measurement;
• Measurement of raw water rate of flow;
• Pace of chemical feed with raw water;
• Adequacy and ease of use of the PLC/PC control system.
The test unit was a full-scale system, which allowed observation of its design and operation. The
control system and the backwash operation were identical to those used in commercial systems.
Therefore, it was possible to evaluate the following operability issues directly during the
verification test:
• Length of filter runs between backwash cycles;
• Change in pressure across the granular media filter module over time;
• Frequency and ease of backwash;
• Ease of operating the computer control system;
• Availability of process data to the operator; and
• Requirements for control and maintenance of the chemical feed systems.
3.5 Field Operations Procedures
Acting as the FTO, the DWTS, conducted the testing of the KemLoop System as described in
this PSTP. DWTS field personnel performed field analytical work using field laboratory
equipment and procedures for pH, temperature, chlorine, turbidity, dissolved oxygen, and true
color. The NSF Chemistry Laboratory performed water quality analytical work.
The test unit was operated 24 hours a day, seven days per week. DWTS staff were on site each
day to operate the system and collect water quality data during the verification test.
3.6 Environmental Technology Verification Testing Plan
A PSTP was prepared for the KemLoop System verification test in accordance with the ETV
Protocol. The PSTP divided the work into three main tasks (A, B, C) with Task C, the
verification test itself, divided into six tasks. These tasks are:
Task A: Raw Water Characterization
17
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Task B: Initial Test Runs
Task C: Verification Test
Task 1: Verification Testing Runs
Task 2: Raw Water, Feed Water, and Filtrate Water Quality
Task 3: Operating Conditions and Performance
Task 4: Arsenic Removal
Task 5: Data Management
Task 6: Quality Assurance/Quality Control (QA/QC)
The PSTP, which included a Quality Assurance Project Plan (QAPP), specified procedures to be
used to ensure the accurate documentation of both water quality and equipment performance.
An overview of each task is provided below with detailed information on testing procedures
presented in later sections.
3.6.1 Task A: Raw Water Characterization
The objective of Task A was to obtain a chemical and physical characterization of the raw water.
Information on the groundwater supply that provides the raw water was needed to aid in
interpretation of feed water characterization.
3.6.2 TaskB: Initial Test Runs
During Task B, ORCA evaluated equipment operation to determine the optimal chemical
dosages and other pretreatment conditions needed to provide effective treatment of the raw
water. ORCA performed all start-up and shakedown testing.
3.6.3 Task C: Verification Test Procedures
Task 1: Verification Testing Runs
The KemLoop System was operated for 14 days (336 hours) to collect data on equipment
performance and water quality for purposes of performance verification. The verification test
period exceeded the 320-hour minimum time specified by the ETV Technology Specific Test
Plan for Coagulation Filtration and the PSTP for the KemLoop System.
Task 2: Raw Water, Feed Water, and Filtrate Water Quality
During verification testing, raw water, feed water (after coagulation), and filtrate water samples
were collected and appropriate sample analyses performed. For example, samples were analyzed
for iron to monitor the coagulation process, in addition to the analyses for arsenic to evaluate
arsenic removal.
Task 3: Operating Conditions and Performance
During verification testing, operating conditions and performance of the water treatment
equipment were documented. Equipment performance information collected included data on
18
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filtrate flow rate and total filtrate volume produced, pressure differential across the granular
media filters, and frequency and duration of backwash.
Task 4: Total Arsenic Removal
Total arsenic in the raw, feed, and filtrate waters were measured to evaluate total arsenic removal
during verification testing..
Task 5: Data Management
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 the ETV DWS Center.
Master field logs were prepared and field sheets for data collection were used to ensure all
scheduled activities were performed. The logs were delivered to the ETV DWS Center project
coordinator on a weekly basis.
Task 6: Quality Assurance/Quality Control (QA/QC)
An important aspect of verification testing was the development of specific QA/QC procedures.
The objective of this task was to assure accurate measurement of operational and water quality
parameters during the verification test.
3.7 Task A: Raw Water Characterization
3.7.1 Site Background Information
Section 1.3 provides a description of the St. Louis Center, its two production wells, and related
water distribution equipment. Historical data, collected by the Center and by NSF, are presented
in Tables 1-1 and 1-2.
3.7.2 Additional Analytical Data
During Task A, additional grab samples of the raw water were collected for characterization
purposes. These data, along with historical data for the groundwater source, provided
characterization of the raw water prior to the startup of the KemLoop System.
Table 3-4 shows the parameters that were analyzed on the initial characterization sample of raw
water in the pressurization tank. A second set of grab samples was collected from each
individual well and from the combined water in the pressure tank for total arsenic analysis.
Information on sampling and analysis methods and procedures is provided later in this chapter.
19
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Table 3-4. Water Quality Parameters for Raw Water Characterization
Raw Water Parameters
PH
Temperature
Turbidity
Alkalinity
Residual Chlorine
Dissolved Oxygen
True Color
Total Arsenic
Arsenic (speciation)
([) Hardness was calculated from calcium
and magnesium measurements.
Iron
Manganese
Chloride
Sulfate
TOC
Fluoride
Calcium(1)
Magnesium^
3.7.3 Evaluation Criteria
The raw water characteristics were evaluated in the context of the ORCA statement of
performance to confirm that the water source was appropriate for verification testing.
3.8 Task B: Initial Test Runs
3.8.1 Objectives
The primary objective of this task was to determine the proper chemical dose for the chlorine
pretreatment and the iron addition to properly co-precipitate arsenic present in the raw water.
The test unit was set up and operated to ensure the unit was properly installed for the verification
test.
3.8.2 Work Plan
ORCA technical support staff worked with the Center's staff to install the equipment and ready
the test system for operation. ORCA staff was on site to direct final connections and the startup
of the equipment. Once the system was ready for operation, ORCA ran the initial startup and
shakedown tests to determine the proper operating conditions, including the optimal chemical
doses for chlorine and iron addition. Results from the shakedown testing are on file at NSF.
Once ORCA confirmed the operating conditions and chemical feed rates recommended for the
verification test, they forwarded the information to NSF. These conditions were the operating
conditions used for the verification test.
3.8.3 Arsenic Loss Test
After ORCA had completed the shakedown testing, the unit was backwashed and then flushed
for two hours using raw water with no chemical feed in preparation for the arsenic loss test. This
test was performed to determine if there was any total arsenic loss in the system when chlorine
and coagulant were not being used. Samples of raw water, feed water, and filtrate were collected
after 6, 12, 18, and 24 hours of continuous operation. Only one backwash cycle based on time
(at end of the 24-hour test) was performed, because the unit pressure and turbidity remained
20
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within specifications throughout the 24-hour test. Operating conditions (flow rate, pressure, etc.)
were monitored and confirmed by the DWTS field staff at the start of the test and every six hours
thereafter. Once this testing was complete and all operating parameters had been confirmed, the
verification test was ready to begin.
3.8.4 Analytical Schedule
During the clean water test run (no chemical addition), grab samples were collected at the times
specified. The four sets of samples (two or three sampling locations per set) were analyzed for
basic water quality parameters and for total arsenic, as shown in Table 3-5. The first and last
samples (6 hours and 24 hours) were analyzed for dissolved arsenic, arsenic (III), and arsenic (V)
to confirm the distribution of arsenic species in the water.
Table 3-5. Water Quality Parameters - Arsenic Loss Test
Parameter Frequency'1' Location
PH
Temperature
Bench Top Turbidity
Inline Turbidity
Alkalinity
Residual Chlorine
True Color
Calcium(2)
Magnesium (2)
Total Arsenic
Arsenic (speciation)
Iron
Manganese
Chloride
Sulfate
Fluoride
TOC
Dissolved Oxygen
4/24 hours
4/24 hours
4/24 hours
Continuous
4/24 hours
4/24 hours
1/24 hours
1/24 hours
1/24 hours
4/24 hours
2/24 hours
4/24 hours
1/24 hours
1/24 hours
1/24 hours
1/24 hours
1/24 hours
4/24 hours
Raw, Feed & Filtrate Water
Raw, Feed & Filtrate Water
Raw, Feed & Filtrate Water
Filtrate Water
Raw, Feed & Filtrate Water
Raw, Feed & Filtrate Water
Raw, Feed & Filtrate Water
Raw & Filtrate Water
Raw & Filtrate Water
Raw, Feed & Filtrate Water
Raw, Feed & Filtrate Water
Raw, Feed & Filtrate Water
Raw & Filtrate Water
Raw, Feed & Filtrate Water
Raw, Feed & Filtrate Water
Raw & Filtrate Water
Raw & Filtrate Water
Raw & Filtrate Water
([) Samples were collected after 6, 12, 18, and 24 hours of operation.
'-2-1 Hardness was calculated from calcium and magnesium measurements.
3.8.5 Evaluation Criteria
The data provided by ORCA for optimal chemical doses and system operating conditions were
reviewed by the FTO. The evaluation focused on the total arsenic removal performance and the
ability of the unit to meet the stated performance objective. These data indicated that the unit
was meeting the performance objective. Therefore, the FTO began preparation for the
verification test using the recommended chemical feed rates and system operating conditions for
the verification test. The total arsenic loss test data were evaluated to determine if total arsenic
was removed or lost in the system when no chemicals were added. This information is presented
in Section 4.4.
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3.9 Task C: Verification Test
3.9.1 Introduction
The verification test was run for 336 hours (14 days), which exceeded the minimum of 320 hours
stated in the Protocol and the PSTP. The test unit was operated continuously, 24 hours a day,
seven days per week. Water quality data for the raw water, feed water, and filtrate were
collected in accordance with the schedule described in the following sections. All samples were
grab samples collected from the sampling ports installed at the site.
The PSTP described six tasks to be performed to achieve a successful verification test. Each of
these tasks is described in this section.
3.9.2 Experimental Objectives
The objective of this task was to assess the ability of the KemLoop System to remove arsenic
from a groundwater source, as indicated in the Statement of Performance Objectives (Section
2.7). The verification test was designed to collect and analyze arsenic performance data,
equipment operating performance data and characteristics, and other water quality information to
achieve this objective. Statistical analyses (standard deviation and confidence intervals) were
performed on all analytes, with eight or more discrete samples collected over the verification
period.
3.9.3 Task 1: Verification Testing Runs
Introduction
The 336-hour verification test used the optimal configuration and filtration operating conditions,
as determined by the shakedown testing, to measure the performance of the KemLoop System
for an extended operating period. The test was typical of operating conditions expected at a
public water supply site using groundwater as the supply source. The quality of the raw water
was not expected to vary significantly over the test period, as deep groundwater sources are
usually fairly stable in quality.
The filtrate produced during the verification was not used for potable water supply purposes.
The filtrate was discharged to the on-site wastewater treatment system.
Operating Schedule
The KemLoop System was operated continuously during the verification test. Flow was
maintained to the system 24 hours per day, seven days per week. During the 336-hour test, the
DWTS field operators recorded daily measurements of the routine operating parameters, as
shown in Table 3-6. In addition, the PLC/PC system also collected and recorded operating data
for the system. Sampling and analyses included one 48-hour intensive survey period. Daily and
weekly sampling and analyses were also performed as described in Section 3.9.4.
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To meet the goals of the verification testing for equipment employing coagulation and granular
media filtration, the following conditions were achieved.
• Water treatment equipment was operated continuously for a minimum of 320 hours (the
equivalent of 13 full days plus one 8-hour work shift).
• The water treatment equipment was operated continuously from start-up until turbidity
breakthrough or terminal head loss was attained, or the maximum cycle time specified
was achieved. ORCA specified a backwash at least once every 24 hours for this site and
test.
• Interruptions in filtration occurred only as needed for backwashing of the filters during
the 336 hours of testing that began on March 24, 2005.
• Filter runs were not stopped before turbidity breakthrough or terminal head loss was
achieved or the maximum cycle time specified was achieved, with the exception of
equipment failure or power interruption.
• The duration of each filter run and the number of gallons of water produced per square
foot of filter area were recorded in the operational results.
Evaluation Criteria
Field logs were used to record all of the information shown in Table 3-6. The hours of operation
needed to meet the protocol requirements were documented. Backwash cycles and times were
recorded. All data are summarized in this final report, including:
• Duration of each filter run;
• Gallons treated per run; and
• Gallons produced per square foot of filter surface.
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Table 3-6. On-site Equipment Operating and Monitoring Data Schedule
Parameter
Monitoring Frequency
Monitoring Method
Feed/filtrate water production
Feed/filtrate water flow rate
Feed water pressure
Filtrate water pressure
Backwash flow rate
Total backwash volume and
duration
Chemical feeds:
Liquid ferric chloride and
sodium hypochlorite (bleach)
Chemicals used
Operating hours
Inline pH meters
Inline turbidimeters
Inline chlorine analyzer
Power use
Labor hours
Check & record once per day. '
Check & record once per day (adjust
when 5% above or below target; record
before and after adjustment).1-1-1
Record initial clean bed total head loss
at start of filter run.
Check & record once per day.1-1-1
Record terminal head loss at end of
filter run.
Record initial clean bed total head loss
at start of filter run.
Check & record once per day.1-1-1
Record terminal head loss at end of
filter run.
Check & record when on site and
backwash is occurring. '
Check & record when on site and
backwash is occurring. -1
Check & record tank height once per
day. Check metering pump setting once
per day or calibrate flow rate.
Whenever a new batch of feed
chemicals is made.
Record once per day the total hours of
operation since last site visit.1-1-1
Verify these meters are operating and
data are recorded daily}1-1
Verify these meters are operating and
data are recorded daily. Verify sample
flow rate daily.-1
Verify these meters are operating and
data are recorded daily.
Determined at end of test.
Determine labor hours required.
System water totalizer meter.
System water flow meter.
Feed water pressure gauge.
Filtrate water pressure gauge.
Determine backwash volume from
holding tank; use stopwatch to time
length of backwash. Calculate flow
rate.
Determine volume by reading tank
depth before and after backwash.
Determine cycle length by
stopwatch.
Measure with measuring tape depth
of chemical remaining and, as
required, quantity of chemical
refill. Calibrate flow rate with
attached graduated cylinder and
stopwatch.
Record name of chemical, supplier,
commercial strength, and dilution
used for making batch solution.
Based on PLC/PC and total volume
meters, determine total hours.
Compare to bench top meter;
calibrate as needed.
Compare to bench top meter;
calibrate as needed. Sample flow
rate by volumetric measurement
over a specific time.
Calibrate as needed.
Power use calculated based on
equipment horsepower ratings.
Record time on-site daily in
logbooks.
*-' PLC recorded these data on a continuous basis (one-minute increments) and stored the data for retrieval to
document the operating parameter throughout the verification test.
'-2-1 PLC recorded these data throughout the verification test for each backwash cycle. Manual readings were made
when backwash occurred during a time when operators were present on site.
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3.9.4 Task 2: Raw Water, Feed Water, and Filtrate Water Quality
Introduction
Water quality data were collected for the raw, feed, and filtrate water on a regular basis during
the verification test, including one 48-hour intensive survey. These data were the basis for
determining the total arsenic removal performance of the system and documenting the water
quality achieved. The sampling and analysis plan also included data collection to monitor the
changes or effects of the coagulant addition (ferric chloride) on water quality.
Work Plan
Monitoring of water quality parameters in the feed water and filtrate water streams provided data
to calculate the changes in the total arsenic concentration and in other inorganic chemicals that
might be affected by the treatment system. Table 3-7 provides a list of the water quality
parameters that were monitored during the verification test, along with the frequency of sampling
for each parameter. In addition to the regular sample collection schedule, one intensive sampling
and analysis period focused on total arsenic removal and the concentration of related process
chemicals, such as iron, pH, turbidity, and residual chlorine. The intensive sampling period is
described further in Section 3.9.6.
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Table 3-7. Sampling
Parameter
Temperature
pH
Alkalinity
Bench Top Turbidity
Inline Turbidity
Hardness(1)
Calcium
Magnesium
TOC
Total Iron
Manganese
Total Arsenic (2)
Sulfate
Chloride
True Color
Residual Chlorine
Fluoride
Dissolved Oxygen
TSS(4)
Total Arsenic (3)
Total Iron1-3
pH(3)
Residual Chlorine(3)
Schedule
Sampling Frequency
Daily
Daily
Daily
Daily
PLC (1/min)
Weekly
Weekly
Weekly
Weekly
Daily
Weekly
Daily
Weekly
Weekly
Weekly
Daily
Weekly
Daily
Weekly
Weekly
Weekly
Weekly
Weekly
Test Streams to be Sampled
Raw, Feed, & Filtrate Water
Raw, Feed, & Filtrate Water
Raw, Feed, & Filtrate Water
Raw, Feed, & Filtrate Water
Raw & Filtrate Water
Raw & Filtrate Water
Raw & Filtrate Water
Raw & Filtrate Water
Raw & Filtrate Water
Raw, Feed, & Filtrate Water
Raw & Filtrate Water
Raw, Feed, & Filtrate Water
Raw, Feed, & Filtrate Water
Raw, Feed, & Filtrate Water
Raw, Feed, & Filtrate Water
Raw, Feed, & Filtrate Water
Raw & Filtrate Water
Raw Water
Backwash Water
Backwash Water
Backwash Water
Backwash Water
Backwash Water
^ Hardness was calculated from calcium and magnesium measurements.
^ Arsenic samples were speciated once per week for raw, feed, and filtrate samples.
'-3-1 Samples were collected on a continuous basis during backwash flow from the backwash inlet line to the holding
tank. One of the weekly samples was collected during the 48 -hour intensive survey. The other weekly sample
was collected when a backwash occurred while the operators are on site.
The FTO field staff measured many of the water quality parameters described in this task while
on site. The NSF Chemistry Laboratory performed analyses of the remaining water quality
parameters. Table 3-8 identifies the methods used for measurement of water quality parameters
26
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and the analysis locations. Further discussion of analytical methods is presented in the QAPP in
the PSTP.
Table 3-8. Analytical Methods
Parameter
Field Tests
PH
True Color(4)
Turbidity
Temperature
Chlorine (total and free)
Dissolved Oxygen
NSF Drinking Water
Laboratory Tests
Arsenic (total)
Arsenic [As (III) and
dissolved]
Calcium
Magnesium
Iron
Manganese
Sulfate
Chloride
TOC
TSS
Fluoride
Alkalinity
Hardness
Contract Lab Tests
Toxicity Characteristic
Leaching Procedure (TCLP)
California Waste Extraction
Test (CAWET)
Facility
On-site
On-site
On-site
On-site
On-site
On-site
Laboratory
Laboratory
Laboratory
Laboratory
Laboratory
Laboratory
Laboratory
Laboratory
Laboratory
Laboratory
Laboratory
Laboratory
Laboratory(5)
TriMatrix
TriMatrix
Standard EPA
Method'1' Method'2'
4500-H+ B
2120B
180.1
2550
4500- G
200.8
200.8
200.7
200.7
200.7
200.8
300.0
300.0
5310 C
2540 D
300.0
2320B
2340 B
1311
Special CA method
and metals by SW846
6010 and 7470a
Hach
Method'3'
8167 (total)
8021 (free)
(3)
(4)
(5)
Standard Methods for the Examination of Water and Wastewater. 1999. 20l edition. APHA, AWWA, and
WEF, Washington D.C.
EPA Methods Source: EPA Office of Ground Water and Drinking Water. EPA Methods are available from the
National Technical Information Service (NTIS).
Hach Water Analysis Handbook (1992). Hach Company, Loveland, Colorado.
The true color test was performed without filtering the sample that is required by the method.
Hardness was calculated from calcium and magnesium measurements.
For the water quality parameters submitted to the NSF Chemistry Laboratory, samples were
collected in appropriate containers (containing necessary preservatives as applicable) prepared
by the NSF Chemistry Laboratory. The samples were stored in coolers and delivered to the
laboratory each day; no commercial shipping was required. All samples were analyzed in
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accordance with appropriate procedures and holding times.
containers, preservatives, and holding time for each parameter.
Table 3-9 shows the sample
Table 3-9. Sample Bottles, Preservation, and Holding Time
Parameter Bottle Type Preservation Holding time
Field Tests
PH
True Color
Turbidity
Temperature
Chlorine (total and free)
Dissolved Oxygen
Plastic
Glass
Glass
Plastic
Plastic
BOD glass bottle
None
Cool to 2-6 °C
None
None
None
None
Analyze immediately
24 hours
Analyze immediately
Analyze immediately
Analyze immediately
Analyze immediately
NSF Lab Tests
Arsenic (total)
Arsenic (As [III] and
dissolved)
Calcium
Magnesium
Iron
Manganese
Sulfate
Chloride
TOC
TSS
Fluoride
Alkalinity
Hardness
Plastic
Plastic
Plastic
Plastic
Plastic
Plastic
Plastic
Plastic
Glass
Plastic
Plastic
Plastic
Plastic
Cool to 2-6 °C
HNO3,
Cool to 2-6 °C
HNO3,
Cool to 2-6 C
HNO
1 11 > \_/3 ,
Cool to 2-6 °C
HNO3,
Cool to 2-6 C
Cool to 2-6 °C
Cool 2-6 °C
Cool 2-6 °C
Cool 2-6 '°C
Cool 2-6 °C
Cool 2-6 °C
Cool 2-6 °C
HNO,
1 11 > \_/3 ,
Cool to 2-6 °C
6 months
6 months
6 months
6 months
6 months
6 months
14 days
14 days
28 days
7 days
14 days
14 days
6 months
Analytical Schedule
The sampling schedule shown in Table 3-7 was designed to frequently monitor the parameters
that are critical to the coagulation and filtration process. General water quality parameters were
monitored on a less frequent basis to provide water quality characteristics. Dissolved oxygen
(DO) concentrations in the raw water were monitored because DO can impact the oxidation of
iron, which is critical to achieve the proper conditions for arsenic coagulation and removal.
All of the water quality parameters listed in Table 3-7 were sampled during the one arsenic
challenge operating condition. The 48-hour intensive survey, described in Section 3.9.6,
occurred during the second week of the 336-hour test. When the intensive arsenic sampling test
was performed, the daily and weekly samples were collected as part of the 48-hour period.
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The raw, feed, and filtrate water were monitored daily for pH because pH is an important part of
the coagulation process. No pH adjustment was needed for the water at this test site. Turbidity
measurements of the raw and filtrate water were made continuously with inline turbidimeters.
These inline units were checked daily using a bench top turbidimeter.
The backwash water was sampled for TSS concentration once per week during a backwash
cycle. Backwash samples were also analyzed for total arsenic, total iron, pH, and residual
chlorine. Samples were obtained continuously to make a composite sample from the inlet line to
the backwash water holding tank.
Typically, the KemLoop System only produces sludge for disposal if the backwash water is
passed through a solids separator or sent to a settling basin to remove suspended solids prior to
discharge. In other applications, the backwash water is discharged to a sewer system and treated
at a wastewater treatment facility. Measuring the TSS, iron, and total arsenic in the backwash
water provides the needed data to assess the quality of the backwash water and its acceptability
to a wastewater treatment plant.
To collect a sample of the solids produced by the backwash, a holding tank was installed to
collect the backwash water. The backwash water was allowed to settle for 24 hours before the
water was manually discharged from the tank. Solids accumulated on the bottom of the tank
over the entire 14-day verification test. Samples of the solids, which represented a composite of
all backwashes that occurred during the 14-day test, were collected to measure the metals that
might leach from the solids produced from the system. The TCLP and CAWET leaching
procedures were both used for these tests. These samples were sent to TriMatrix Laboratories in
Grand Rapids, Michigan, for analysis. TriMatrix Laboratories was approved by NSF to perform
these analyses for purposes of the verification test.
Water Quality Sample Collection
Water quality data were collected at the specified intervals during the testing period. The
monitoring frequency for the water quality parameters is shown in Table 3-7. 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.
All samples were grab samples collected from the sampling valves installed in the test system.
Samples were collected from a raw water sample tap prior to chlorine addition, at the feed water
sample port after all chemical additions and mixing just prior to the filtration unit, and from the
filtrate (treated water) sample tap, located downstream of the granular media filter module. Prior
to collecting the sample, each valve was flushed for at least five seconds to be sure fresh water
was obtained from the process lines. The samples were collected directly into a clean, large
container. Aliquots of samples were then poured into the required containers for laboratory
analysis or on-site analysis. Samples from all three locations were collected within less than 15
minutes so that data were representative of the current conditions.
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Backwash samples were taken continuously over the entire backwash cycle from the inlet line to
the holding tank. These samples represented the average concentration over the backwash cycle.
Special sampling procedures were used for turbidity. Grab samples were taken by running a
slow, steady stream from the sample tap, triple-rinsing a dedicated sample beaker in this stream,
allowing the sample to flow down the side of the beaker to minimize bubble entrainment,
double-rinsing the sample vial with the sample, carefully pouring from the beaker down the side
of the sample vial, wiping the sample vial clean, inserting the sample vial into the turbidimeter,
and recording the measured turbidity.
Temperature measurements were performed by collecting a sample into a clean container and
immediately immersing the thermometer into the water.
Evaluation Criteria and Minimum Reporting Criteria
Performance was evaluated in the context of the manufacturer's statement of performance
objectives.
Since iron was used as the coagulant, the filtered water data were tabulated and the concentration
of iron in filtered water was compared to the Secondary Maximum Contaminant Level (SMCL)
of 0.3 mg/L.
Given that the verification test was for a groundwater source, turbidity results were analyzed to
determine the percentage of turbidity data in the ranges of 0.50 NTU or lower, 0.51-1.0 NTU,
1.1-2.0 NTU, and exceeding 2.0 NTU.
Other water quality data are presented in this final report in either graphical or tabular format.
Daily analyses are plotted against time, while weekly parameters are summarized in a tabular
format. Information includes:
• A graph plotting the daily turbidity, pH, alkalinity, and iron for the raw, feed, and filtrate
water over the test period.
• A table summarizing the raw, feed, and filtrate water concentrations of hardness,
manganese, TOC, sulfate, chloride, and true color.
• A table summarizing the residual chlorine data and calculation of total chlorine fed to the
system (mass or volume).
• Appendices containing all data collected during the verification test.
3.9.5 Task 3: Operating Conditions and Treatment Equipment Performance
Introduction
The objectives of this task were to accurately and fully document the operating conditions during
treatment and evaluate the equipment performance. Operating conditions, including flow rates
through the granular media filter, pressure drop across the filter, frequency and duration of filter
backwash cycles, and any maintenance required, were documented during each day of
30
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verification testing. Electrical use was calculated from the horsepower ratings for the pumps and
other equipment.
Work Plan
A description of the equipment, granular media filter characteristics, and test system operating
conditions was presented in Chapter 2. During verification testing, operating parameters were
routinely monitored by the DWTS on-site staff. Table 3-6 presented a list of the normal
operating parameters that were monitored to document the equipment performance during the
verifications test.
The following items were monitored, collected, recorded, or analyzed:
• Treatment equipment operating parameters for both pretreatment and filtration, including:
- Monitoring iron dose and pH for the coagulation system; and
- Monitoring the chlorine pre-oxidation.
• Filter head loss before and after backwash cycles, and backwashing data (frequency, flow
rate, volume).
• Chemical dosages for all chemicals used including oxidants and ferric chloride were
monitored. Chlorine was used as an oxidant. The chlorine dosage and residual chlorine
were measured daily, including when total arsenic samples were collected. Iron
concentrations in the raw and feed water were analyzed to track iron dose, in addition to
monitoring the iron usage.
• Electrical energy consumed by the treatment equipment based on the aggregate
horsepower of all pumps and mixers was calculated and reported.
Schedule for Operating Parameter Data Collection
Table 3-6 shows the list of operating parameters that were monitored during the verification test
and the frequency of the observations.
Evaluation Criteria
The data developed from this task were used to present operating data on system flow rate, head
loss (pressure drop) across the filter module, and frequency and duration of filter backwash
cycles.
The results of operating and performance data were tabulated and included:
• Average volume of flow treated, gpd;
• Average filtrate water flow rate, gpm;
• Average filtration rate, gfd;
• Average run length, hours, and volume of water treated per filter run;
• Average daily chemical usage;
• Average pressure drop across the module;
• Average daily backwash water production; and
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• Typical suspended solids in the backwash.
3.9.6 Task 4: Arsenic Removal
Introduction
Total arsenic removal was the primary objective of the coagulation and granular media filtration
process evaluated in this verification test. Assessment of the treatment efficiency was based on
total arsenic removal.
Work Plan
Task 4 was performed concurrently with Task 1. The treatment equipment was operated using
the chemical treatment conditions and system operating conditions that provide effective
coagulation and filtration.
Evaluation of total arsenic removal was performed by analyzing total arsenic in the raw, feed,
and filtrate waters. The total arsenic evaluation included monitoring total arsenic concentration
on a daily basis, as shown in Table 3-7, and during one intensive sampling period over 48 hours.
The intensive sampling period was performed during the second week of the verification test,
beginning on Day 7 and ending on Day 9. During this intensive sampling period, samples were
collected at the start (time zero), 1, 3, 6, 12, 18, and 24 hours. The filter then entered a backwash
cycle based on time. When the backwash cycle ended, the sampling schedule was reset to time
zero for the start of the next sampling on a clean filter module. Samples were collected at time 0,
1, 3, 6, 12, 18, and 24 hours, which completed the 48-hour intensive survey. A total of 14
samples were collected over the 48-hour period.
Analytical Schedule
In addition to monitoring arsenic concentration, the concentration of iron, which was used as the
coagulant to co-precipitate arsenic, was measured in each raw, feed, and filtrate water sample.
The complete list of parameters monitored, sampling frequencies, and location of samples are
shown in Table 3-10.
Chlorine dose and residual chlorine were monitored daily throughout the verification. During
the intensive sampling period, residual chlorine was analyzed on every sample. The KemLoop
process included a pre-oxidation step with chlorine to covert any arsenic (III) to arsenic (V) and
to oxidize iron species in the raw water. It has been demonstrated by many researchers that
arsenic (V) removal by coagulation and filtration is much more effective than arsenic (III)
removal. Thus, ORCA has implemented the preferred approach and used pre-oxidation to
convert all arsenic to arsenic (V) to attain the most effective results.
Turbidity in raw water and filtrate was determined using continuous flow turbidimeters equipped
with recording capability via the PLC. Data were collected on a 24-hour-per-day basis during
verification testing. The recording increment in the PLC for turbidity and other operating data
was one minute. The inline turbidity readings were also recorded once per day in the field log.
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Raw water, feed water and filtrate turbidity was monitored once per day using a bench top
turbidimeter. The bench top results were used to check the calibration of the inline units.
The regular daily and weekly sample analyses for total arsenic and other water quality
parameters were discussed in Section 3.9.4, Task 2. Total arsenic samples were collected daily,
and one sample each week was speciated. The sampling schedule was summarized in Table 3-7.
During the week of the 48-hour intensive survey, the results from the 48-hour test were used to
satisfy the daily or weekly requirements for those days and that week.
The KemLoop System had a maximum detention time in the mixing loop of approximately five
minutes. The first samples at time zero were collected approximately 30 minutes after the
backwash cycle was completed to ensure the filter was operating at a steady state condition.
Evaluation Criteria
KemLoop System performance was evaluated based on the data collected and in the context of
the manufacturer's statement of performance objectives. The following information is
summarized and discussed in Chapter 4 of this report:
• Valence of the arsenic being treated by the process (i.e., arsenic [III] or arsenic [V]);
• pH of coagulated water;
• Turbidity levels associated with each sample for total arsenic;
• Coagulant chemical used;
• Coagulant dosage or concentration of iron coagulant; and
• Concentration of chlorine added.
Since iron was used as the coagulant, the filtrate data were tabulated and the concentration of
iron in filtrate was compared to the SMCL of 0.3 mg/L.
The following data are presented in Chapter 4:
• The total arsenic data are plotted against sample time to show trends and variations in
performance.
• The turbidity, pH, and iron for the raw, feed and filtrate over the 48-hour intensive survey
are presented.
• A table summarizing the raw, feed, and filtrate water concentrations of hardness,
manganese, TOC, sulfate, chloride, and true color.
• A table summarizing the residual chlorine data and a calculation of the amount of
chlorine fed to the system each day.
All field logs with recorded operating data and field analytical data, NSF laboratory reports, and
spreadsheets summarizing the results are presented in Appendices B, C, and D.
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Table 3-10. Parameter List for the 48-Hour Intensive Survey
Parameter
Sampling
Frequency
Test Streams Sampled
Total Arsenic
Arsenic Speciation
Temperature
pH
Alkalinity
Bench Top Turbidity
Inline Turbidity
Hardness®
Calcium
Magnesium
TOC
Iron
Manganese
Sulfate
Chloride
Fluoride
True Color(3)
Residual Chlorine
Dissolved Oxygen
Total Arsenic (4)
Total Iron(4)
pH(4)
Residual Chlorine(4)
All samples1^
0, 24, 48 hours
0, 24, 48 hours
All samples
0, 24, 48 hours
0, 24, 48 hours
For all arsenic samples by
continuous meter
Once at 24 hrs
Once at 24 hrs
Once at 24 hrs
Once at 24 hrs
All samples
Once at 24 hrs
Once at 24 hrs
Once at 24 hrs
Once at 24 hrs
Once at 24 hrs
All samples
0, 24, 48 hours
Every backwash cycle
Every backwash cycle
Every backwash cycle
Every backwash cycle
Every backwash cycle
Raw, Feed, &
Raw, Feed, &
Raw, Feed, &
Raw, Feed, &
Raw, Feed, &
Raw, Feed, &
Filtrate Water
Filtrate
Filtrate
Filtrate
Filtrate
Filtrate
Filtrate
Water
Water
Water
Water
Water
Water
Raw & Filtrate Water
Raw & Filtrate Water
Raw & Filtrate Water
Raw & Filtrate Water
Raw, Feed, & Filtrate Water
Raw & Filtrate Water
Raw, Feed, & Filtrate Water
Raw, Feed, & Filtrate Water
Raw & Filtrate Water
Raw, Feed, & Filtrate Water
Raw, Feed, & Filtrate Water
Raw & Filtrate Water
Backwash Water
Backwash Water
Backwash Water
Backwash Water
Backwash Water
All samples refers to time 0, 1, 3, 6, 12, 18, 24, and time 0, 1, 3, 6, 12, 18, 24 after the first backwash occurred
after 24 hours of operation.
Hardness was calculated from calcium and magnesium measurements.
The true color test was performed without filtering the sample that is required by the method.
Samples were collected on a continuous basis during backwash flow from the backwash inlet line to the holding
tank. Samples were collected for each backwash that occurred during the 48 -hour intensive survey.
3.9.7 Task 5: Data Management
Introduction
The data management system used in the verification test included the use of computer
spreadsheets and manual (or inline) recording of operational parameters for the equipment on a
daily or weekly basis. The FTO field staff collected the information and entered it into logbooks
and prepared field log sheets. All field activities were documented. Field documentation
included field logbooks, photographs, field data sheets, and chain- of- custody forms. The
procedures for logbook format and entries followed the procedures outlined below:
• Field notes were kept in a bound logbook;
• Pre-prepared log sheets were used to record all water treatment equipment operating data;
• Each log sheet was labeled with the project name and the verification day number;
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• Completed pages were signed and dated by the individual responsible for the entries; and
• Errors were corrected by drawing a single line through the error. The line was initialed
and dated.
Any deviations from the approved final PSTP were documented in the field logbook and
included in the report. A copy of the PSTP was available on site.
Chain-of-custody forms accompanied all samples delivered to the analytical laboratory. Copies
of field sheets and chain-of-custody forms for all samples were provided at the time of QA/QC
inspection and are included in Appendices B and C.
Objectives
The objectives of this task were to: 1) establish a viable structure for the recording and
transmission of field testing data such that the FTO provided sufficient and reliable data for
verification purposes, and 2) develop a statistical analysis of the data, as described in the
document: EPA/NSF ETV Protocol for Equipment Verification Testing for Arsenic Removal:
Requirements For All Studies and Chapter Three of the same document.
Work Plan
The DWTS field operators recorded on-site data and calculations (e.g., calculating calibration
flow rates using the "bucket and stop watch" technique and other similar routine calculations) by
hand in field logbooks and field log sheets. Daily measurements were recorded on specially
prepared data log sheets. The original logbooks were stored on site. Copies were forwarded to
the project coordinator at NSF weekly during the testing period. Operating logs included a
description of the equipment, description of test runs, names of visitors, description of any
problems or issues, and so forth.
A database for the project was set up using standard spreadsheets. The spreadsheets were
capable of storing and manipulating each monitored water quality and operational parameter
from each task, sampling location, and sampling time. All data from the on-site laboratory
logbooks and data log sheets were entered into the appropriate spreadsheets. Scherger
Associates, the consultant to the DWTS, performed the data entry. Following data entry, the
spreadsheets were printed, and the printout was checked against the handwritten data sheet. NSF
DWS Center project coordinators checked 100% of the spreadsheet entries and provided written
notes on the corrections that needed to be made. Final versions of the spreadsheets were checked
to ensure all corrections had been made and all entries were correct.
As samples were collected and sent to the NSF Chemistry Laboratory, they were tracked by use
of chain-of-custody forms. Each sample had its location name, date, time of collection, and the
parameters written on the label. These laboratory data were entered into data spreadsheets,
corrected, and verified in the same manner as the field data.
The KemLoop System PLC/PC stored and archived operating data monitored by the unit. The
PLC acquired data in one minute or more frequent (5 minute, 10 minute, etc.) increments.
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The data for parameters such as flow and pressure were averaged on an hourly basis, and
maximum and minimum values were determined. The PLC stored the data for the two-week
period. The on-site laptop PC was used to access the PLC data. The PLC data were downloaded
to a PC for display and storage at the end of the test. The PC data were backed at the end of the
verification test. A copy of the PLC data is located in Appendix B.
3.9.8 Task 6: Quality Assurance/Quality Control
Introduction
QA/QC of the operation of the KemLoop System and the measured water quality parameters
were maintained during verification testing by following the QAPP developed as part of the
PSTP (Chapter 5). The QAPP included accuracy and precision objectives for the analytical
work, discussion of the need to meet representativeness and completeness criteria, and
calibration requirements for field meters and analytical equipment/methods.
On-site Equipment Checks
Equipment flow rates were documented and recorded on a daily basis. A daily walkthrough
during testing was established to verify that each piece of equipment or instrumentation was
operating properly. Inline monitoring equipment, such as flow meters and so forth, were
checked to confirm that they were operating properly.
The items listed below were performed in addition to any specified checks outlined in the
analytical methods.
Daily QA/QC Verifications:
• Turbidity calibration of the inline meters checked by comparison with bench top
turbidimeter results; and
• Change in chemical tank volumes calculated to confirm calibration of each metering
pump.
Weekly QA/QC Verifications:
• Inline flow meters cleaned of any fouling buildup, as needed. Flow rate verified
volumetrically using the bucket and stop watch or tank fill time;
• Inline totalizer meter cleaned of any material buildup as needed. Production rate verified
volumetrically and volume monitored and recorded over time based on calibrated flow
rate;
• Tubing, piping, and connections verified to be in good condition and replaced as
necessary; and,
• Chemical metering pumps flow rate verified by graduated cylinder attached and stop
watch.
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One-Time QA/QC Verifications:
• Accuracy of pressure gauges was confirmed based on receiving a manufacturer's
calibration statement. All gages were new.
Analytical Methods
The analytical methods utilized in this verification test for laboratory samples and for on-site
monitoring of water quality are shown in Table 3-8.
Sampling procedures are described in Section 3.9.4. All samples were grab samples taken at
designated sampling ports. The sampling valves were flushed for a minimum of five seconds
before a grab sample was collected.
The QAPP provided specific calibration procedures for the analytical methods performed on site
and also a summary of the laboratory calibration requirements based on the analytical methods.
The NSF Chemistry Laboratory performed all water quality analyses using EPA or Standard
Methods procedures as shown in Table 3-8. All of the required calibration curves and quality
control procedures were documented in accordance with the published methods, and as described
in the QAPP in the PSTP.
3.10 Operation and Maintenance
A draft O&M manual was received from ORCA when the KemLoop System was installed. NSF
reviewed the O&M manual and evaluated the instructions and procedures for their applicability
during the verification test and for overall completeness. Results of the O&M manual review are
reported in Chapter 4.
3.10.1 Maintenance
Evaluation during the verification test and review of the O&M manual included confirmation
whether the manufacturer provided readily understood information on the recommended or
required maintenance schedule for the following:
Operating equipment:
• Pumps,
• Valves,
• Pressure gauges,
• Flow meters,
• Chemical feeders,
• Motors,
• Flow meters, and
• Continuous turbidimeters and pH meters.
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Non-mechanical or non-electrical equipment:
• Tanks,
• Piping, and
• Filter modules.
3.10.2 Operation
The following operating aspects were evaluated.
Pre-oxidant generation/feed:
• Measurement of pre-oxidant concentration fed.
Chemical feeder pumps:
• Calibration check;
• Settings and adjustments, with instructions on changing; and
• Dilution of chemicals, including proper procedures.
Granular media filtration:
• Control of filtration flow and rate; and
• Observation and measurement of head loss across the media during the filter run.
Granular media backwashing:
• Programming of automated frequency,
• Use of alternative water source,
• Proper backwash venting and disposal,
• Appropriate backwash rate, and
• Observation during return of filter to service.
Monitoring and observing operation:
• Filtered and raw water turbidity,
• Filtered and raw water pH,
• Filter head loss,
• Measurement of the iron coagulant dose, and
• Measurement and control of the pH of coagulated water.
The protocol recommends that a manufacturer provide a troubleshooting guide with a simple
checklist of what to do for a variety of problems, including:
• No raw water (feed water) flow to plant;
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• Inability to control rate of flow of water through equipment;
• No chemical feed;
• Loss of pre-oxidant feed;
• Calibration and maintenance of inline pH monitoring instruments, problems of erratic pH
or drifting pH readings;
• Inability to backwash filter or to change backwash rate of flow;
• No reading on turbidimeter;
• Automatic operation (if provided) not functioning;
• Filtered water turbidity too high;
• Excessive and rapid filter head loss build up;
• Valve stuck or inoperable;
• Low feed pump pressure;
• Pump cavitation; and
• No electric power.
The O&M manual was reviewed for the information and degree of detail provided on these and
other operating conditions observed during the verification test.
3.10.3 Operability Evaluation
The following formed the basis of the review and evaluation for equipment operability during
verification testing. These aspects of plant operation were reported to the extent practical in the
verification report.
The factors considered included:
• Fluctuation of chemical feed rate from the desired value:
- How long can feed pumps hold the feed rate on a set value?
- How frequently is resetting needed?
• Ability to maintain desired pre-oxidant feed rate.
• Presence of devices to aid the operator with chemical dosage selection:
- Influent and filtered water continuous turbidimeters provided?
- Inline pH meter provided?
- Inline free chlorine analyzer provided?
• Can automatic backwash be initiated by:
- Reaching a set value for head loss?
- Reaching a set turbidity level in the treated water?
- Default minimum time?
• Does plant have multiple feed points for chemicals:
- For pH adjustment?
- For coagulant chemical feed?
- For oxidants?
• Is granular media pressure differential measurement provided?
• Is rate of flow of raw water measured?
• Is chemical feed paced with raw water flow?
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• Can coagulation pH be maintained automatically if raw water flow changes?
• Is backwash rate of flow measured and variable?
• Is backwash duration (time) variable?
Other factors and questions included:
• Does the equipment have sensors or monitoring equipment that can detect an equipment
malfunction, unsatisfactory filtrate water quality, or operating conditions that exceed
allowable limits?
• If so, during such situations can the equipment be automatically shut down?
• Upon automatic shutdown, can notification be provided if the operator is not present on
site?
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Chapter 4
Results and Discussion
4.1 Introduction
The verification test program for the KemLoop System began with equipment installation at the
St. Louis Center in Chelsea, Michigan, on February 22, 2005 and ended with the completion of
the verification test on April 6, 2005. The test site was described in Section 1.3. The KemLoop
System was described in Chapter 2.
The equipment was installed the week of February 20, 2005. ORCA conducted start-up and
shakedown testing through March 11, 2005. Raw water characterization samples were collected
on February 24 and March 9, 2005. The arsenic loss test was performed from March 14-15,
2005. The 14-day (336 hour) verification test, including a 48-hour intensive survey, was
performed from March 23 through April 6, 2005.
This chapter presents a summary of the water quality and operating data collected during the
verification test. Activities and data collected during the start-up and shakedown of the
equipment, raw water characterization, and the arsenic loss test describe activities performed
prior to the actual 14-day verification test. The results for the 14-day verification test are
presented, including data on raw water, feed water, and filtrate water arsenic and other water
quality parameters. Operating data are presented to describe the flow rates, volume of treated
water produced, backwash volumes and frequency, pressure differential across the filter, and
related operating information. QA/QC information, as described by the QAPP in the PSTP for
this verification test, is presented at the end of the chapter.
4.2 Equipment Installation, Start-up, and Shakedown
ORCA personnel installed the equipment at the site with assistance from the Center staff during
the week of February 20, 2005. The unit was shipped as a complete system inside of a standard
8 X 20 foot shipping container, except for the filtrate water and backwash water holding tanks.
Piping was installed to route raw water from the pressure supply tank inside the building to the
KemLoop System, which was placed outside the building. The raw water line included a back
flow preventer and pressure regulator to control pressure and flow to the unit. The KemLoop
System included locations in the raw water line to inject sodium hypochlorite (source of
chlorine) and ferric chloride (coagulant), using chemical metering pumps supplied by ORCA.
The system installation was completed over a three-day period.
During the week of February 28, ORCA ran a series of tests that included operating at varying
doses of ferric chloride and residual chlorine in the feed water to the mixing loop. The inline
analyzers for pH and turbidity were used to monitor the system, along with a field test kit to
check the iron concentration in the feed and filtrate water. Samples of raw water, feed water
(after chemical addition), and filtrate water were collected for laboratory analysis for total
arsenic. Eight filtrate samples were collected under varying operating conditions and analyzed
for arsenic concentration. Six of the eight samples were below the detection limit of 1 |ig/L; the
other two results were in the 1-3 |ig/L range.
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The data obtained by ORCA are on file at NSF. Based on the data, ORCA set the basic
operating conditions that were used for the verification test.
Results of the shakedown tests showed that arsenic could be removed at a total residual chlorine
concentration of 1 mg/L in the filtrate, and with the addition of approximately 1.5-2.5 mg/L (as
Fe) of ferric chloride, supplementing the naturally occurring iron in the raw water
(approximately 0.5 mg/L). Results showed that pH adjustment was not needed. The data
suggested that lower doses of ferric chloride could achieve similar results, but ORCA determined
that the best operating condition for this water was to use 2 mg/L (as Fe) of ferric chloride, and 1
mg/L total residual chlorine with no pH adjustment. These concentrations of oxidant and
coagulant were the target chemical concentrations used for the 14-day verification test.
The pressure differential on the filter only increased slightly after two days of operation without
backwashing the filters, and the filtrate turbidity remained low. Therefore, ORCA determined
that backwash cycles would be set to operate on time, in addition to pressure differential and
turbidity differential. Backwash was set to occur once every 24 hours. The PLC was set to
initiate a backwash if the pressure differential increased to 8 psi or when the effluent turbidity
increased to a level higher than the raw water turbidity for more than ten minutes.
The KemLoop System was operated from March 3-14, 2005, when the unit was backwashed and
prepared for the arsenic loss test. During this time, ORCA staff monitored the system from their
office using the on-site laptop PC and an Internet connection. The ORCA staff also checked on
the unit on a regular basis and filled the chemical feed tanks as needed.
4.3 Task A: Raw Water Characterization
Historical water quality data collected by NSF at the Center for the individual wells and the
combined water were obtained in the initial planning stage for this verification test. As shown in
Table 1-1 and 1-2, the total arsenic concentrations were in the range of 14-48 |ig/L, and total iron
ranged from 0.36-2.8 mg/L. A sample of the combined water in the pressure tank, which was the
raw water source for this verification test, was collected on February 24, 2005. The chemical
analyses included total arsenic and arsenic speciation (arsenic [III] and [V]) and other water
quality parameters.
The results of the initial raw water characterization test are presented in Table 4-1. The data
confirmed that the raw water quality was similar to the historical water quality used to plan the
verification test. However, the results for total and speciated arsenic had high detection limits
due to an apparent interference in the raw water sample in the laboratory. Therefore, additional
samples, including samples of each well and the combined raw water as it was fed to the
KemLoop System, were collected on March 9, 2005, for total arsenic analysis. The treatment
unit was operating at this time, so a sample of filtrate was also collected. These data are included
in Table 4-1. The second set of samples confirmed that the raw water contained total arsenic at
levels that had been measured in the past and were acceptable for the verification test.
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Table 4-1. Raw Water Characterization Data - February 24 and March 9,
Parameter
Date
pH
Temperature
Turbidity
Free Chlorine
Total Chlorine
Dissolved Oxygen
True Color(2)
Alkalinity
Total Arsenic
Dissolved Arsenic
Arsenic (III)
Arsenic (V)
Iron
Manganese
Chloride
Sulfate
TOC
Fluoride
Calcium
Magnesium
Hardness
Date
Total Arsenic
Units
S.U.
°c
NTU
mg/L
mg/L
mg/L
C.U.
mg/L as CaCO3
H8/L
H8/L
Hg/L
Hg/L
mg/L
V-S/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L as CaCO3
Lig/L
Combined
Wells (1) Well#l Well #2
2/24/05
7.41
HI
1.2
<0.05
<0.05
6.4
13
250
<2
<20
<20
<20
0.39
12
33
20
0.6
0.6
71
28
290
3/9/05
18 16 19
2005
Filtrate
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
<2
"—" = Not required or scheduled for analysis.
^ Combined sample taken from pressure tank.
^ High color may be due to oxidation of iron. In addition, color sample was not filtered before analysis.
4.4 Task B: Initial Test Runs
4.4.1 Arsenic Loss Test
The arsenic loss test, to determine if arsenic is removed and retained by the system without
chemical addition, was performed over a 24-hour period beginning on March 14, 2005. The
system had to be clean prior to starting the test. Therefore, a backwash cycle was initiated prior
to testing. The unit was placed in normal treatment mode at a flow rate of approximately 10 gpm
with all chemical feeds turned off. The system was operated for two hours prior to starting the
arsenic loss test. This provided an ample flushing time in case any residual chemically treated
water remained in the mixing loop, which had a retention time of approximately five minutes.
The operating data and results from the 24-hour arsenic loss test are shown in Table 4-2. A
fairly steady flow rate averaging 10.3 gpm was maintained during the test run. The total volume
processed during the 24-hour period was 14,970 gallons. The pressure differential between the
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feed water (filter inlet) and the filtrate (filter outlet) did not increase during the 24-hour period,
varying from 0-4 psi.
Table 4-2.
Date
3/14/05
3/15/05
Arsenic Loss Test Operating Data
Time
11:30
18:02
00:01
06:10
12:00
Raw
Pressure
(psi)
32
42
40
36
38
Feed
Pressure
(psi)
4
5
4
3
3
Filtrate
Pressure
(psi)
0
2
1
3
0
Pressure
Delta(1)
(psi)
4
3
3
0
3
Flow
Rate
(gpm)
9.9
11.6
10.8
10.3
9.0
Total Volume
Treated
(gal)
0
3,710
6,520
11,470
14,970
^^ Pressure Delta is the pressure differential or head loss through the filter as measured by the pressure difference
between the feed and filtrate.
Tables 4-3 and 4-4 show the water quality for the arsenic loss test. All statistical calculations of
these data are presented in Appendix D. There was only a small loss of arsenic through the
system over the 24-hour test, with feed water total arsenic averaging 19 |ig/L and the filtrate
averaging 16 |ig/L. Arsenic (III) was the predominate arsenic species in the raw water. Only a
slight oxidation of the arsenic was observed as the water came in contact with oxygen and passed
through the system. The small arsenic loss was most likely associated with arsenic coagulated
with the naturally occurring iron and removed with the iron on the filters. Turbidity, iron, and
color were removed by the filtration system as expected. All other water quality indicators
remained steady and passed through the filter. It should be noted that the raw water sample was
taken from the pressure tank outlet line where it entered the treatment system shipping container.
The high color in the raw water is not typical of a deep groundwater. Naturally occurring iron
oxidizing in the pressure tank may have caused the high color. Also, the sample was not filtered
prior to measuring the color.
44
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Table 4-3. Arsenic Loss Test Water Quality Results
Parameter Units
Total Arsenic l^g/L
Dissolved Arsenic ug/L
Arsenic (III) l^g/L
Arsenic (V) l^g/L
Iron mg/L
pH (bench top) S.U.
pH (inline) S.U.
Temperature °C
Turbidity (bench N™ ,
top)
Turbidity (inline) NTU
AH r •+, mg/L as
Alkalinity s
CaCO3
Free Residual /T
™ , • mg/L
Chlorine &
Residual Chlorine mg/L
Dissolved Oxygen mg/L
Raw Water
3/14/05
18:02
20
19
16
3
0.38
7.35
7.44
11.3
1.14
0.908
270
O.05
O.05
4.5
00:01
18
—
—
—
0.39
7.39
7.46
11.0
1.18
0.761
280
O.05
<0.05
4.0
3/15/05
06:10
19
—
—
—
0.38
7.06
7.45
11.0
1.01
0.901
270
<0.05
O.05
6.3
12:00
20
16
14
2
0.38
7.48
7.46
11.3
0.19
0.485
270
<0.05
O.05
4.0
Feed Water
3/14/05
18:02
20
20
14
6
0.35
7.43
7.50
11.4
0.89
—
270
O.05
O.05
—
00:01
19
—
—
—
0.34
7.40
7.48
11.9
1.02
—
270
O.05
<0.05
—
3/15/05
06:10
19
—
—
—
0.33
7.39
7.48
11.6
1.31
—
270
<0.05
O.05
—
12:00
19
18
14
4
0.33
7.38
NR
11.5
0.86
—
270
O.05
O.05
—
Filtrate
3/14/05
18:02
15
17
12
5
O.02
7.44
—
11.6
0.15
0.054
270
O.05
O.05
4.0
3/15/05
00:01 06:10
15 20
—
—
—
0.05 O.02
7.44 7.47
—
12.2 11.4
0.28 0.33
0.053 0.05
270 270
O.05 O.05
O.05 O.05
4.2 5.0
12:00
16
10
7
3
0.07
7.44
7.48
13.0
0.19
0.309
280
O.05
O.05
5.2
Note: Turbidity monitored at start of test (11:30 AM) - Raw water: 0.71 NTU; Filtrate: 0.06 NTU.
pH monitored at start of test (11:30 AM) -Raw water: 7.41;Feed: 7.22; Filtrate: 7.26.
Dissolved oxygen monitored at start of test (11:30 AM) - Raw water: 4.6 mg/L; Filtrate: 4.4 mg/L.
NR = Not Recorded.
"—" = Not required or scheduled for analysis.
45
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Table 4-4. Arsenic Loss Test Daily Water Quality Results
March 15,2005
12:00
Parameter Units Raw Feed Filtrate
Manganese
Calcium
Magnesium
Hardness
Chloride
Sulfate
Fluoride
TOC
True Color(1)
Hg/L
mg/L
mg/L
mg/L as CaCO3
mg/L
mg/L
mg/L
mg/L
C.U.
11
74
23
280
11
19
0.5
0.6
7
11
74
23
280
11 11
19 19
0.5
0.6
14 <1
"—" = Not required or scheduled for analysis.
^ The true color test was performed without filtering the sample that is required by the method.
At the end of the arsenic loss test, the filter was backwashed and a sample of the backwash water
was collected and analyzed. The backwash contained 240 ug/L of total arsenic and 31 mg/L of
iron. The TSS concentration was 86 mg/L. The total residual chlorine and free residual chlorine
results showed a concentration of 1.0 mg/L residual chlorine in the backwash water. However,
this was a false positive reading due to the presence of a yellow color in the backwash water that
interfered with the residual chlorine test. The backwash water pH was 7.56.
4.5 Task C: Verification Test
4.5.1 Operating Results
The KemLoop System was backwashed and the verification test started on March 21, 2005. The
KemLoop System was set to the operating criteria established by ORCA during the shakedown
testing. Chemical feeds were established to supply sufficient bleach to maintain total residual
chlorine in the feed water of approximately 0.5-1.0 mg/L. The ferric chloride feed rate was set to
deliver 2 mg/L of ferric chloride (as Fe) to the raw water. Based on the previous operating data,
the flow rate for filtrate was set at 10 gpm to give a target filter surface-loading rate of 2,940 gfd,
based on 24-hour filter runs. The backwash system was set to backwash the filter every 24 hours
unless initiated automatically due to a pressure differential of 8 psi or if the filtrate turbidity was
higher than the raw turbidity for 10 minutes. The backwash cycle was set to four minutes in
length at a flow rate of approximately 55-60 gpm.
On March 22, it was discovered that the ferric chloride metering pump had fallen off its stand,
and ferric chloride had leaked from a broken inlet pipe. The spilled material was cleaned up, the
problem was fixed, and the system was placed back in operation. The verification test was
scheduled to restart on March 23. The KemLoop System backwash was set to backwash every
46
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24 hours at approximately 10:40 AM. Therefore, the verification test started officially at 11:40
AM on March 23, following completion of the backwash cycle and approximately one half hour
for the system to stabilize. The verification test ended on April 6 at 11:40 AM, 336 hours (14
days) later. During the verification test, the KemLoop System operated continuously 24-hours
per day.
Table 4-5 shows the daily operating data for the verification test. The filtrate flow rate remained
steady for most days during the test, yielding an average flow rate of 9.9 gpm over the 14 days.
The total filtrate volume produced each day was also consistent, except for April 2-4, when
volumes and flow rates were somewhat lower. It appears the pressure on the raw water supply
tank at the Center was periodically dropping below 40 psi (the setting on the pressure regulator).
This caused periodic lower flow rates and lower volumes of filtrate to be produced over the 24-
hour period. The average hydraulic loading through the filter was 2,890 gfd, based on the 24-
hour filter run time between backwashes and the average daily filtrate production of 14,630
gallons.
The pressure on the system was monitored at three locations: raw water, feed water (inlet to the
filter), and filtrate (exit of the filter). There was very little change in head loss through the filter
over each 24-hour operating period. The maximum pressure differential observed was 5.0 psi.
The filter was set to backwash automatically if the pressure differential reached 8.0 psi. The
automatic backwash cycle was not triggered due to pressure differential (head loss) at any time
during the verification test.
The filter was backwashed every 24 hours on a time basis. The successful completion of the
backwash cycle was confirmed each day by the DWTS field staff. All backwash water was
collected in a holding tank. Each day the on-site operator checked the water level in the holding
tank to confirm how many backwashes had occurred. The operator then emptied the tank
manually. The operators reported that one backwash had occurred each day during the
verification test. In each case this backwash was based on the maximum time of 24 hours
between backwashes having been achieved.
The time to complete the backwash cycle was measured once during the arsenic loss test and
four times during the verification test. Backwash cycle time varied from 4 minutes to 4 minutes
10 seconds. The backwash volume was monitored on eight days during the verification test by
observing the volume of water generated during the previous 24-hour period. The total
backwash volume generated averaged 220 gallons per backwash.
47
-------
Table 4-5. Operating Data
Date
3/23/05U)
3/24/05
3/25/05
3/26/05
3/27/05
3/28/05
3/29/05
3/30/05
3/31/05
4/1/05
4/2/05
4/3/05
4/4/05
4/5/05
4/6/05
Number of
samples
Average
Maximum
Minimum
Std. Deviation
95% Conf.
Interval
Filtrate
Flow
Rate(2)
(gpm)
14.4
11.1
10.7
10.5
9.6
9.9
10.8
9.7
10.3
10.0
9.9
6.1
8.5
10.2
10.7
14
9.9
11.1
6.1
1.2
(9.1,10.6)
Total
Filtrate
Volume (3)
(gal)
0
15,180
15,650
14,280
15,190
15,600
15,310
14,960
15,070
15,700
12,750
12,620
11,280
15,950
14,940
14
14,630
15,600
11,280
1420
(13,810,
15,450)
Raw
Pressure
(psi)
38
43
37
45
32
37
40
34
38
40
40
35
34
40
40
14
38
45
32
3.6
(36,40)
Feed
Pressure
(psi)
21
5.0
5.5
7.5
6.8
7.0
5.0
6.0
5.5
5.5
6.5
5.5
5.0
5.0
5.0
14
5.8
7.5
5.0
0.85
(5.3,6.3)
Filtrate
Pressure
(psi)
17
3.0
3.0
3.0
2.5
3.0
1.0
3.5
2.5
3.0
3.0
1.0
0.0
0.0
0.0
14
2.0
3.5
0.0
1.3
(1.3,2.8)
Filter
Pressure
Difference
(psi)
4.0
2.0
2.5
4.5
4.3
4.0
4.0
2.5
3.0
2.5
3.5
4.5
5.0
5.0
5.0
14
3.7
5.0
2.0
1.1
(3.1,4.3)
Operating
Hours
(hours)
0
24
24
24
24
24
24
24
24
24
24
24
24
24
24
14
24
24
24
NC
NC
*• ' The March 23r data are for day zero and are the readings taken at the start of the test. These data are not
included in the statistical calculations. They are provided for information only.
Flow rate was the instantaneous reading each morning when the field staff checked the system.
The gallons produced per filter run correspond to the daily filtrate volume, as the filter was backwashed once
every 24 hours.
NC = Not Calculated.
4.5.2 Arsenic Results
The determination of total arsenic removal using the KemLoop System was the primary
objective of the verification test. This section presents the arsenic results for the raw, feed, and
filtrate water monitored daily during the verification test. Also included are the results from the
48-hour intensive survey, when samples for arsenic analysis were collected on a more frequent
basis. The total arsenic data are presented in Tables 4-6 and 4-7. Arsenic speciation data are
presented in Table 4-8. Figure 4-1 shows the arsenic results plotted for the 14-day test.
The total arsenic in the raw water and feed water averaged 23 ug/L and 22 ug/L, respectively,
based on the daily sample results. Over the 14-day period, the maximum total arsenic was 32
48
-------
Hg/L in the raw water and the minimum was 19 |ig/L. The arsenic speciation data for the raw
water showed that most of the arsenic was present as arsenic (III).
The KemLoop System removed total arsenic to less than detection limit (1 |ig/L) on 6 of the 14
days tested. Total arsenic exceeded 10 |ig/L, the maximum contaminant level (MCL), on two
days, the first and last days of the test. The average filtrate concentration was 3 |ig/L. The
average value and other statistics shown in Tables 4-6 and 4-7 were calculated by using the value
of the detection limit for concentrations reported below the detection limit of 1 |ig/L. The
samples that had an elevated detection limit of <10 |ig/L where excluded from the statistics so
that the statistics were not biased by these elevated detection limit results.
The total arsenic result for the first day (March 25) was above 10 |ig/L, which is the MCL for
drinking water. The elevated arsenic filtrate level on the first sampling day can be attributed to
an overdose of ferric chloride that occurred during the previous 24 hours of operation. Also, the
turbidity level in the filtrate was above 1 NTU, the highest turbidity level recorded during the
verification test. The high turbidity occurred during the last two hours of the filter run prior to
backwash; the filtrate sample was collected just before the backwash occurred after 24 hours of
operation. In addition, the soluble arsenic for this sample was <1 |ig/L, indicating the arsenic in
the filtrate was in the particulate form. The data indicate that the arsenic was being precipitated
in the mixing loop, but some of the particulate was passing through the filter. After the first day,
the filtrate arsenic levels dropped to near or below the detection limit until the last day of the test,
when a filtrate concentration of 11 |ig/L was recorded. There was no significant change in the
filtrate turbidity or iron concentration on this day; both were low and in the typical range of
previous days. No explanation could be found as to why the filtrate arsenic concentration was
elevated on this day.
The laboratory noted a matrix interference in three filtrate samples. The samples required a
dilution of 10:1, which raised the detection limit to 10 |ig/L. A similar interference was found in
the raw water samples collected in February for raw water characterization. The source of the
interference was not known.
The chemical addition of sodium hypochlorite (targeted to maintain 1 mg/L of total residual
chlorine) and ferric chloride (target feed of 2 mg/L as Fe) was effective in oxidizing the arsenic
(III) to arsenic (V) and precipitating and coagulating the arsenic in the raw water. As shown in
Table 4-8, most of the arsenic present in the raw water was in the soluble form, as arsenic (III).
The feed water data show that after chemical oxidation and coagulation, all of the arsenic was
present in the particulate form, and there were generally low to non-detectable levels of soluble
arsenic in the feed water. The effectiveness of this oxidation and precipitation process was key
to the results obtained by the KemLoop System. After chemical treatment, all or most of the
arsenic was in the particulate form, which the granular filtration system was able to remove. The
result was a filtrate with a low level of arsenic.
The data collected during the 48-hour intensive survey were consistent with the data collected
each day during the verification test. There was no indication of any transient or short time
changes in the arsenic concentration or in any other monitored parameters.
49
-------
Table 4-6. Daily Total Arsenic Results (ug/L)
Date Raw Feed Filtrate'1'
3/24/05
3/25/05
3/26/05
3/27/05
3/28/05
3/29/05
3/30/05
3/31/05
4/1/05
4/2/05
4/3/05
4/4/05
4/5/05
4/6/05
Number of samples
Average
Maximum
Minimum
Std. Deviation
95% Conf. Interval
28
24
23
25
21
20
23
25
<10(2)
19
25
32
20
19
13
23
32
19
3.8
(21, 26)
24
23
23
23
21
27
22
24
19
20
23
19
19
21
14
22
27
19
2.3
(21, 23)
12
1
<1
3
1
<1
<1
2
<10(3)
<1(4)
<1
<1
1(4)
11
13
3
12
<1
4
(<1, 5)
^ Concentrations reported as <1 set equal to the detection limit for calculating statistics.
^ Raw water value considered an outlier; not included in statistics.
'-3-1 This result is not included in the statistics due to the high detection limit.
'-4-1 These results are from the duplicate analyses for these samples. The first sample in both cases was reported as
50
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Table 4-7. Total Arsenic Results for 48-Hour Intensive Survey (ug/L)
Date Time Raw Feed Filtrate'1'
3/30/05
3/30/05
3/30/05
3/30/05
3/30/05
3/31/05
3/31/05
3/31/05
3/31/05
3/31/05
3/31/05
3/31/05
4/1/05
4/1/05
Number of samples
Average
Maximum
Minimum
Std. Deviation
95% Conf. Interval
11:15
12:30
14:30
17:25
23:30
05:30
11:30
11:45
12:30
14:30
17:15
23:22
05:40
11:10
23
23
23
23
25
22
25
25
27
24
18
20
23
<10(3)
13
23
27
18
2.3
(22, 25)
22
20
22
24
20
21
24
25
23
23
19
19
24
19
14
22
25
19
2.1
(21, 23)
<1
<1
<1
2
<1
<1
2
<10(2)
1
1
1
<1
2
<10(2)
12
1
2
<1
0.4
(<1, 2)
^•* Concentrations reported as <1 set equal to the detection limit for calculating statistics.
'-2-1 These results are not included in the statistics due to the high detection limit.
^ Raw water value considered an outlier; not included in statistics.
51
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Table 4-8. Arsenic Speciation Data (
Total Arsenic Dissolved Arsenic Arsenic (III) Arsenic (V)
Date Raw Feed Filtrate Raw Feed Filtrate Raw Feed Filtrate Raw Feed Filtrate
3/24/05
3/24/05
3/30/05
3/31/05
4/1/05
Day 1
Duplicate
Day 7
Day 8(1)
Day 9
28
28
23
25
<10
24
23
22
24
19
12 23
12 22
<1 20
2 62
<10 <10
<1
<1
12
4
<10
<1
<1
3
15
<10
21
21
17
22
21
<1
<1
2
2
<1
<1 2
<1 1
<1 3
1 40
<1 <10
<1
<1
10
2
<10
<1
<1
3
14
<10
March 31 Day 8 sample results appear to be anomalous.
52
-------
u
'E
15
'o
35 i
30-
25-
20
15
10
A
X S
/ s
•. V-'-T
s
Date
- • Raw — •• — Feed
- Filtrate
Figure 4-1. Verification test daily arsenic results.
53
-------
4.5.3 Raw, Feed, and Filtrate Water Quality Results
Water quality data were collected each day for pH, temperature, turbidity, and chlorine (total and
free residual). Samples for iron and alkalinity analyses were also collected daily. These
parameters were key water quality indicators and important to this technology, which uses
chlorine oxidation and iron coagulation as part of the process. Dissolved oxygen was monitored
daily in the raw water, as it can affect the oxidation of iron and arsenic (III). Other water quality
parameters were monitored on a weekly basis, including calcium, magnesium, total hardness,
manganese, sulfate, chloride, fluoride, TOC, and color. All of the field data log sheets and
laboratory reports are included in Appendices B and C.
Tables 4-9 and 4-10 present the individual pH measurements for the daily samples and for the
48-hour intensive survey. Figure 4-2 shows the pH for the raw, feed, and filtrate water from the
daily samples. The raw water pH was steady in the range of 7.20-7.48 during the verification
test period. The addition of chlorine and ferric chloride had very little impact on the feed water
pH. Feed pH ranged from 7.10-7.49, which was similar to the raw water results. The negligible
impact of the chemical addition on feed water pH was most likely due to the high alkalinity of
the raw water and the small amount of chemical required at this site. Other locations with lower
alkalinity or sites requiring higher chemical doses may exhibit a larger change in pH in the feed
water. The filtrate pH was very similar to the feed water pH, as expected. The filtrate pH ranged
from 7.22-7.46, with a median value of 7.30. The pH during the 48-hour intensive survey was
monitored frequently and showed similar results to the daily pH levels found over the 14-day
verification test.
Table 4-9. pH Results (S.U.)
Date Raw Feed Filtrate
3/23/05
3/24/05
3/25/05
3/26/05
3/27/05
3/28/05
3/29/05
3/30/05
3/31/05
4/1/05
4/2/05
4/3/05
4/4/05
4/5/05
4/6/05
Number of samples
Median
Maximum
Minimum
7.38
7.32
7.48
7.26
7.28
7.47
7.39
7.27
7.30
7.30
7.32
7.47
7.29
7.20
7.24
15
7.30
7.48
7.20
7.10
7.34
7.35
7.24
7.45
7.49
7.35
7.31
7.28
7.22
7.32
7.40
7.22
7.19
7.27
15
7.31
7.49
7.10
7.30
7.28
7.26
7.26
7.46
7.40
7.44
7.38
7.30
7.22
7.34
7.37
7.28
7.23
7.26
15
7.30
7.46
7.22
54
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Table 4-10.
pH Results (Bench Top) for the 48-Hour
Intensive Survey (S.U.)
Date
3/30/05
3/30/05
3/30/05
3/30/05
3/30/05
3/31/05
3/31/05
3/31/05
3/31/05
3/31/05
3/31/05
3/31/05
4/1/05
4/1/05
Time
11:15
12:30
14:30
17:25
23:30
05:30
11:30
11:45
12:30
14:30
17:15
23:22
05:40
11:10
Number of samples
Median
Maximum
Minimum
Raw
7.27
7.59
7.50
7.47
7.25
7.37
7.30
7.34
7.31
7.30
7.17
7.04
7.37
7.25
14
7.31
7.59
7.04
Feed
7.31
7.50
7.48
7.37
7.22
7.46
7.28
7.33
7.18
7.15
7.18
7.01
7.34
7.28
14
7.30
7.50
7.01
Filtrate
7.38
7.49
7.41
7.36
7.26
7.42
7.30
7.37
7.23
7.20
7.24
7.19
7.18
7.26
14
7.28
7.49
7.18
55
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7.6 i
7.5 -
7.4-
_ 7.3 •
3
S2-
Q.
7.2 -
7.1 -
7.0 -
6.9
3/23/2005 3/24/2005 3/25/2005 3/26/2005 3/27/2005 3/28/2005 3/29/2005 3/30/2005 3/31/2005 4/1/2005 4/2/2005 4/3/2005 4/4/2005 4/5/2005 4/6/2005
Date
-••»• -Raw — -B — Feed
-Filtrate
Figure 4-2.. Verification test pH results.
56
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Tables 4-11 and 4-12 present the individual turbidity measurements for the daily turbidity levels
and for the 48-hour intensive survey. Figure 4-3 shows the turbidity for the raw, feed, and
filtrate water from the daily samples. The filtrate turbidity was low, averaging 0.30 NTU based
on the bench top turbidimeter used by the field personnel. In addition to the bench top turbidity
meter, the KemLoop System had inline turbidity meters on the raw and filtrate water lines. The
inline turbidimeter showed the filtrate averaged 0.179 NTU.
The bench top turbidity meter always gave higher turbidity readings compared to the inline units.
As an example, the raw water turbidity based on the bench top unit averaged 2.4 NTU, whereas
the average turbidity based on the inline unit was 0.578 NTU. The inline unit was calibrated
using appropriate standards, as was the bench top unit. It is believed that the bench top unit data
may have been biased high due to temperature and slight fogging issues that can be problematic
when collecting cold samples and transferring them to the bench top vials. Based on the bench
top meter measurements, the filtrate was below 0.5 NTU in 93% of samples. There were no
values between 0.5 and 1 NTU, and 7% of the readings (1 reading) were between 1 and 2 NTU.
No turbidity levels were measured above 2 NTU. The inline turbidimeter gave the same
distribution of turbidity readings in the filtrate.
During the 48-hour intensive survey, the turbidity readings were taken from the inline turbidity
unit. Results during the 48-hour intensive survey were very similar to the daily results over the
14-day verification test. The turbidity levels in the filtrate did tend to increase slightly near the
end of each filter run. Turbidity appeared to increase slightly and then decrease after the active
filter was taken off line for backwashing and the standby filter was brought on line. However,
all turbidity measurements for the filtrate were below 0.2 NTU, even at the end of a 24-hour run.
57
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Table 4-11. Turbidity Results (NTU)
Turbidity (bench top)(1)
Date
3/23/05
3/24/05
3/25/05
3/26/05
3/27/05
3/28/05
3/29/05
3/30/05
3/31/05
4/1/05
4/2/05
4/3/05
4/4/05
4/5/05
4/6/05
Number of samples
Average
Maximum
Minimum
Std. Deviation
95% Conf. Interval
Raw
3.15
0.67
1.58
0.96
5.62
4.81
1.54
1.04
2.54
1.74
1.16
6.84
1.92
1.74
1.20
15
2.4
6.8
0.65
1.9
(1.4, 3.5)
Feed
4.04
2.45
2.10
1.53
4.70
1.38
1.62
2.18
2.28
1.83
2.00
1.64
1.76
3.14
0.96
15
2.2
4.7
0.95
1.0
(1.7, 2.8)
Bench top
Filtrate
1.85
0.37
0.13
0.32
0.19
0.17
0.21
0.30
0.21
0.10
0.10
0.04
0.33
0.21
0.32
15
0.30
1.9
O.05
0.45
(0.1, 0.55)
Turbidity (inline)
Raw
NR
0.96(2)
0.347
0.513
0.680
0.554
0.670
0.495
0.407
0.570
0.750
0.441
0.544
0.650
0.505
14
0.578
0.96
0.347
0.157
(0.487, 0.668)
Inline meter
Filtrate
1.36
0.232
0.034
0.260
0.039
0.089
0.127
0.185
0.096
0.032
0.051
0.037
0.035
0.077
0.036
15
0.179
1.36
0.032
0.335
(0.000, 0.365)
1' Bench top statistics have been rounded according to the Standard Method guidelines.
2' The field log recorded this result as 0.096 NTU, but review of the PLC records indicates the value should be
reported as 0.96 NTU.
NR = Not Recorded.
58
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Table 4-12. Inline Turbidity Results for the 48-Hour
Intensive Survey (NTU)
Date
Time
Raw
Filtrate
3/30/05
3/30/05
3/30/05
3/30/05
3/30/05
3/31/05
3/31/05
3/31/05
3/31/05
3/31/05
3/31/05
3/31/05
4/1/05
4/1/05
11:15
12:30
14:30
17:25
23:30
05:30
11:30
11:45
12:30
14:30
17:15
23:22
05:40
11:10
Number of samples
Average(1)
Maximum
Minimum
Std. Deviation
95% Conf. Interval
0.495
0.531
0.568
0.715
0.680
0.679
0.407
0.605
0.491
0.490
0.860
0.731
0.654
0.569
14
0.605
0.860
0.407
0.122
(0.535, 0.676)
0.185
0.046
0.031
0.047
0.030
0.045
0.096
0.034
0.035
0.035
0.065
0.036
0.036
0.070
14
0.057
0.185
0.030
0.041
(0.033, 0.080)
TTT
Statistics have been rounded according to the Standard Method guidelines.
59
-------
Date
- Raw — -• — Feed
•Filtrate Bench top
Filtrate Inline meter
Figure 4-3. Verification test turbidity results.
60
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Figure 4-4 presents the alkalinity results for the raw, feed, and filtrate water. The raw water
averaged 260 mg/L as CaCCb and was stable throughout the test. The maximum concentration
was 270 mg/L and the minimum was 220 mg/L. The alkalinity in the feed water also averaged
260 mg/L, with a maximum of 270 mg/L and a minimum of 220 mg/L. There was no change in
alkalinity through the filter. The filtrate alkalinity averaged 260 mg/L, with a maximum of 270
mg/L and a minimum of 220 mg/L. The alkalinity concentration during the 48-hour intensive
survey was similar to the levels found during the entire verification test, as shown in Table 4-13.
61
-------
cr
o
re
O
V)
re
O)
290
270
250 •
230 •
210-
190
170
150
Date
• Raw — •• — Feed
• Filtrate
Figure 4-4. Verification test alkalinity results.
62
-------
Table 4-13. Alkalinity Results for the 48-Hour Intensive
Survey (mg/L as CaCQs)
Date Time Raw Feed Filtrate
3/30/05
3/31/05
3/31/05
4/01/05
11:15
11:30
11:45
11:10
270
240
240
260
260
240
240
260
260
230
240
250
Figure 4-5 shows the total iron concentrations measured in the raw, feed, and filtrate water. The
raw water contained naturally occurring iron, averaging 0.47 mg/L with a maximum of 1.0 mg/L
and minimum of 0.34 mg/L. The pre-testing by ORCA showed that this amount of iron was not
sufficient to provide the desired arsenic removal performance, so additional iron was added to
the system to achieve the needed iron concentrations for coagulation of the arsenic. The feed
water averaged 1.9 mg/L as Fe with a median concentration of 1.8 mg/L. The maximum iron
concentration in the feed water was 4.5 mg/L on March 24, the first day of the test. The iron
dose was decreased on March 24 and remained close to the targeted 2.0 mg/L for the remaining
days of the test. On March 28 and 29 the iron level in the feed water decreased to 0.37 and 0.96
mg/L, respectively. There was no apparent reason for this decrease. Arsenic removal remained
consistent on these days.
63
-------
o
Date
' 'Raw — •• — Feed A Filtrate |
Figure 4-5. Verification test iron results.
64
-------
The KemLoop System removed the iron present in the feed water, producing treated water that
had 0.03 mg/L or less on all but three days. On March 24, the first day of the test, when the iron
concentration in the feed was measured at a maximum concentration of 4.5 mg/L, the filtrate
concentration was 1.7 mg/L. On March 27 the iron concentration was 0.31 mg/L, just above the
MCL. Iron was detected at 0.07 mg/L on March 31. This sample was taken just before the filter
backwash during the 48-hour intensive survey. Table 4-14 shows the iron results for the 48-hour
survey. The data show that the KemLoop System can generally achieve the statement of
performance objective of producing a filtrate with <0.30 mg/L of iron.
Table 4-14. Iron Results for the 48-Hour Intensive
Survey (mg/L)
Date Time Raw Feed Filtrate
3/30/05
3/30/05
3/30/05
3/30/05
3/30/05
3/31/05
3/31/05
3/31/05
3/31/05
3/31/05
3/31/05
3/31/05
4/1/05
4/1/05
11:15
12:30
14:30
17:25
23:30
05:30
11:30
11:45
12:30
14:30
17:15
23:22
05:40
11:10
Number of samples
Average
Maximum
Minimum
Std. Deviation
95% Conf. Interval
0.37
0.49
0.54
0.41
0.33
0.38
0.53
0.37
0.35
0.34
<0.02(1)
0.40
0.38
0.34
13
0.40
0.54
0.33
0.07
(0.36, 0.45)
2.4
2.0
3.0
2.8
2.2
0.39
2.4
1.6
2.9
2.7
0.42
2.7
0.54
1.8
14
2.0
3.0
0.39
0.93
(1.5, 2.5)
O.02
<0.02
<0.02
<0.02
<0.02
O.02
0.07
O.02
O.02
O.02
O.02
O.02
O.02
O.02
14
O.02
0.07
O.02
NC
NC
(' Data considered an outlier; not used in calculating statistics.
NC = Not Calculated.
The field staff measured total and free residual chlorine daily. Table 4-15 shows the residual
chlorine data for the raw, feed, and filtrate water. The raw water is a non-chlorinated source and
should have no residual chlorine. The data show this was the case on most days, with total and
free residual chlorine measuring below the detection limit. As shown in Table 4-16 during the
48-hour survey, one result indicated the presence of total residual chlorine at 0.10 mg/L. It is not
known why an occasional sample showed chlorine present in the raw water samples. These data
appear to be anomalous readings. There is no reason to believe that chlorine is present in the raw
water source.
65
-------
During the verification test, the feed water averaged 1.01 mg/L of total residual chlorine, and the
filtrate water averaged 0.95 mg/L. Most of the data points were clustered in the range of 0.85-
1.15 mg/L. The free residual chlorine results show that a large percentage of the total residual
chlorine was combined chlorine. It is apparent that this groundwater source contained
constituents that combined with the chlorine. The free residual chlorine in the feed water
averaged 0.22 mg/L, and the filtrate averaged 0.18 mg/L. The bleach solution was fed at a target
rate of 2.2 mg/L to maintain approximately 1.0 mg/L of total residual chlorine in the feed water,
indicating the raw water had a chlorine demand of approximately 1.2 mg/L.
Table 4-15. Total and Free Residual Chlorine (mg/L)
Free Chlorine
Date
3/23/05
3/24/05
3/25/05
3/26/05
3/27/05
3/28/05
3/29/05
3/30/05
3/31/05
4/1/05
4/2/05
4/3/05
4/4/05
4/5/05
4/6/05
Number of samples
Average
Maximum
Minimum
Std. Deviation
95% Conf. Interval
Raw
0.09(U
O.05
O.05
O.05
<0.05
<0.05
<0.05
<0.05
O.05
O.05
O.05
O.05
<0.05
O.05
<0.05
14
O.05
0.09(1)
O.05
NC
NC
Feed
0.11
0.43
0.09
O.05
0.07
0.12
0.64
0.10
0.06
0.31
0.12
0.33
0.20
0.38
0.23
15
0.22
0.64
0.05
0.17
(0.12,0.31)
Filtrate
0.05
0.24
O.05
O.05
0.04
0.05
0.73
O.05
O.05
0.14
0.34
0.28
0.21
0.34
0.06
15
0.18
0.73
0.04
0.19
(0.07, 0.28)
Total Chlorine
Raw
O.05
O.05
O.05
O.05
O.05
O.05
O.05
O.05
O.05
O.05
O.05
O.05
O.05
O.05
O.05
15
O.05
O.05
O.05
NC
NC
Feed
0.85
1.17
1.10
1.10
1.05
1.13
1.04
1.10
1.05
1.07
1.10
0.75
0.80
0.97
0.80
15
1.01
1.17
0.75
0.14
(0.93, 1.08)
Filtrate
0.85
1.15
1.04
1.11
1.00
0.96
1.07
1.08
1.00
0.85
0.97
1.01
0.69
0.98
0.46
15
0.95
1.15
0.46
0.18
(0.85, 1.05)
Dissolved
Oxygen
Raw
3.7
5.9
3.6
4.4
5.3
4.0
5.0
4.6
3.6
2.5
3.0
3.8
3.7
4.3
3.5
15
4.1
5.9
2.5
0.9
(3.6, 4.5)
( ' Value judged to be anomalous data based on total result chlorine result and not included in the statistical
calculations.
Note: Concentrations reported as "less than values" set equal to the detection limit for calculating statistics.
NC = Not calculated.
66
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Table 4-16. Free and
Date Time
3/30/05 11:15
3/30/05 12:30
3/30/05 14:30
3/30/05 17:25
3/30/05 23:30
3/31/05 5:30
3/31/05 11:30
3/31/05 11:45
3/31/05 12:30
3/31/05 14:30
3/31/05 17:15
3/31/05 23:22
4/1/05 5:40
4/1/05 11:10
Number of samples
Average
Maximum
Minimum
Std. Deviation
95% Conf. Interval
Total Residual Chlorine Results for 48-Hour Survey (mg/L)
Raw
O.05
O.05
O.05
O.05
O.05
O.05
O.05
O.05
<0.05
<0.05
<0.05
<0.05
O.05
O.05
14
<0.05
O.05
<0.05
NC
NC
Free Chlorine
Feed
0.10
0.07
0.13
0.08
0.12
0.10
0.06
0.24
0.30
0.17
0.11
0.07
0.22
0.15
14
0.14
0.30
0.06
0.07
(0.10,0.18)
Filtrate
<0.05
<0.05
0.17
0.11
0.06
O.05
O.05
0.33
0.13
0.18
0.14
0.05
0.20
0.12
14
0.12
0.33
0.05
0.08
(0.07,0.17)
Total Residual
Raw
O.05
O.05
O.05
NA
0.10
O.05
O.05
O.05
O.05
O.05
NA
<0.05
<0.05
<0.05
12
O.05
0.10
<0.05
NC
NC
Feed
1.10
1.06
1.15
NA
1.13
0.95
1.05
0.83
1.23
1.14
NA
1.08
1.01
0.74
12
1.04
1.23
0.74
0.14
(0.95, 1.13)
Chlorine
Filtrate
1.08
1.10
1.11
1.08
1.06
1.00
1.00
0.82
0.94
0.92
0.57
0.80
0.87
0.57
14
0.92
1.11
0.57
0.18
(0.82, 1.03)
NA = Not analyzed.
NC = Not calculated.
Note: Concentrations reported as "less than values" set equal to the detection limit for calculating statistics.
The results for the other water quality parameters are shown in Table 4-17. The raw water
concentrations were stable throughout the test. The feed and filtrate water showed similar
average concentrations of sulfate, TOC, fluoride, calcium, magnesium, and manganese. The
KemLoop System had little or no impact on these water quality parameters. The chloride
concentration increased 4-7 mg/L in the feed and filtrate water due to the addition of ferric
chloride. Manganese was present at an elevated level in the filtrate water on one day, March 24.
The manganese was reported as 180 ug/L, ten times higher than the raw water. The laboratory
data were checked for a calculation error or a matrix interference, but no errors or interferences
were apparent. The cause of this increase on manganese for one day is not known.
Temperature was monitored daily in the raw, feed, and filtrate water. The mean temperature of
the raw water was 12.0 °C. The feed water and filtrate temperatures were similar to the raw
water, with mean values of 12.3 °C and 12.8 °C, respectively.
During the verification test, the true color in the raw water and the filtrate was higher than would
be expected in deep groundwater and filtered water. (Note that true color was measured directly,
and samples were not filtered prior to measurement.) Color in water typically occurs when
organic matter degrades to form dissolved organic carbon. TOC concentrations did not change
during the arsenic loss test (Table 4-4) or during the verification test (Table 4-17). Whatever the
source of TOC in this water, the filtration process, with or without coagulation, did not remove
67
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the organic material. While the organic carbon might play a role in the color levels measured,
the TOC results did not change, whereas the color results varied considerably. These data, and
the fact that the wells drew from 125-150 feet below grade and were not influenced by surface
water, suggest that the difference in the color of the raw water originated from colloidal
formation of iron (US EPA. July 1976. Quality Criteria For Water.). This would cause a high
color reading in a sample that was not filtered. Iron is naturally present in this water and may
have oxidized in the pressure tank before withdrawal fcr treatment. The DO in the raw water
was in the 2.5-5.9 mg/L range. This would indicate that some oxidation could occur. The
possible cause of the color levels measured in the filtrate is not as clear. The filtrate was low in
turbidity and iron, which would indicate that suspended solids were removed. The filtrate was
clear when inspected visually. The color data may not be indicative of actual conditions,
although there was no apparent problem in the analyses.
Table 4-17. Other Water Quality Parameters
Date
3/24/05
3/31/05
4/1/05
Number of samples
Average
Maximum
Minimum
Raw
12
14
15
3
14
15
12
Chloride
(mg/L)
Feed
19
19
19
3
19
19
19
Filtrate
19
18
20
3
19
20
18
Raw
17
18
19
3
18
19
17
Sulfate
(mg/L)
Feed
17
18
19
3
18
19
17
Filtrate
18
17
19
3
18
19
17
TOC
(mg/L)
Raw Filtrate
0.6 0.6
0.5 0.5
0.5 0.6
3 3
0.5 0.6
0.6 0.6
0.5 0.5
Date
3/24/05
3/31/05
4/1/05
Number of samples
Average
Maximum
Minimum
Fluoride
(mg/L)
Raw Filtrate
0.4 0.5
0.6 0.6
0.5 0.6
3 3
0.5 0.6
0.6 0.6
0.4 0.5
Calcium
(mg/L)
Raw Filtrate
76 75
73 73
73 72
3 3
74 73
76 75
73 72
Magnesium
(mg/L)
Raw Filtrate
23 23
23 23
24 23
3 3
23 23
24 23
23 23
Hardness
(mg/L as CaCQ,)
Raw Filtrate
280 280
280 280
280 270
3 3
280 280
280 280
280 270
68
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Table 4-17. Other Water Quality P.
Manganese
Date
3/23/05
3/24/05
3/31/05
4/1/05
Number of samples
Average
Maximum
Minimum
(ug/L)
Raw
—
18
14
<10
3
14
18
<10
Filtrate
—
180
9
<10
3
66
180
<10
arameters (continued)
True Color*1'
(C.U.)
Raw
19
—
14
10
3
14
19
10
Feed
46
—
29
34
3
36
46
29
Filtrate
24
~
3
17
3
15
24
3
1' The true color test was performed without filtering the sample that is required by the method.
4.5.4 Backwash Water Frequency and Quality
As described in Chapter 2, the KemLoop System backwash cycle can be automatically initiated
by pressure differential, turbidity differential, time, or filtrate volume produced. During the
verification test, all of the backwash cycles were initiated based on time, because the pressure
differential and turbidity differential set points were not reached during any 24-hour filter run.
The backwash water was discharged through a separate backwash line that was sampled during
the verification test.
The backwash water was sampled and analyzed during the verification test. A composite sample
was collected from the backwash discharge line before the water entered the holding tank. Table
4-18 shows the results for total arsenic, total iron, TSS, and pH. Free and total residual chlorine
were also analyzed on the samples, but results were not considered accurate, due to the presence
of background color in the samples, and are not reported. All of the free and total residual
chlorine results were much higher than concentrations measured in the feed and filtrate water,
indicating a strong positive bias in the sample results. The color in the backwash samples clearly
interfered with these analyses.
The backwash water was enriched in arsenic, iron, and TSS, as would be expected, given the
removal of arsenic and iron as measured in the filtrate. The KemLoop System produced an
average daily filtrate volume of 14,600 gallons and generated an average backwash volume of
220 gpd. Thus, on a mass balance basis, the concentration of arsenic and iron would be
projected to increase by a factor of approximately 66. The average iron concentration in the feed
water was 1.9 mg/L. Therefore, the projected iron concentration in the backwash water would be
130 mg/L. The results are very close to the projected concentrations, indicating most or all of
the iron precipitate was being removed from the filter during the backwash cycle. The arsenic
mass balance shows a projected backwash concentration of 1250 |ig/L versus a measured
average of 990 |ig/L, calculated without the apparent outlier on April 1. The balance is
reasonably good, considering the backwash water samples only represented three or four days of
operation.
69
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Table 4-18. Backwash Water - Water Quality Results
Total Arsenic
Date (ug/L)
3/27/05
3/30/05
4/1/25
4/6/05
Number of samples
Average1-2-1
Maximum
Minimum
1000
1100
870
64(1)
4
760
1100
64
Total Iron
(mg/L)
130
150
100
100
4
120
150
100
TSS
(mg/L)
280
300
230
200
4
253
300
200
PH
(S.U.)
7.50
7.13
7.11
7.32
4
7.13
7.50
7.11
^^ Result appears to be an outlier based on iron data and previous results.
'-2-1 Median reported for pH, not the average.
NC = Not Calculated.
Local disposal requirements determine whether a water is acceptable for discharge to a sanitary
sewer system or another discharge location, or if it requires further treatment prior to discharge.
The suspended solids present in the backwash water can be expected to contain most of the
arsenic and iron, because the basis of the technology is to precipitate arsenic with iron in the
mixing loop. If solid separation were required before the backwash water could be discharged,
the solids would need to be sent to a landfill for disposal. A sample of the solids accumulated
over the 14-day test, which settled to the bottom of the holding tank, was collected and analyzed
by the TCLP and the CAWET. This sample represented a composite of all solids generated
during the verification test, not from just a single day or single backwash cycle. The backwash
solids were not considered a hazardous waste based on the arsenic concentrations, which were
below the 5 mg/L limit under the Resource Conservation and Recovery Act (RCRA). Table 4-19
presents the results of the TCLP and CAWET analyses. The laboratory test report received from
TriMatrix Laboratories is included in Appendix E.
Table 4-19. Backwash Solids - TCLP and CAWET Analyses
Parameter Units TCLP CAWET
Arsenic
Barium
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Silver
Zinc
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
0.32
2.6
O.010
O.050
0.015
O.050
O.0002
0.011
O.10
O.010
2.1
3.1
1.3
O.010
O.050
0.041
0.11
O.010
<0.25
0.19
0.020
1.2
4.5.5 Chemical Consumption
The KemLoop System used a 6% sodium hypochlorite (bleach) as the stock chemical for adding
chlorine to the system. The stock feed was made by diluting 12% bleach at a ratio of one to one
70
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with water. The targeted total residual chlorine concentration in the feed water was 1 mg/L.
Based on preliminary test data, the chemical metering pump was set to feed approximately 1.3
mL/min (1.9 L/day) from the five-gallon container of bleach solution. Approximately 28 liters
of 6% bleach solution were used to treat 204,870 gallons of raw water over the 14-day
verification test. In the absence of any chlorine demand in the raw water, the calculated chlorine
concentration at this feed rate was approximately 2.2 mg/L. The theoretical amount of bleach
solution needed to achieve the measured average total residual chlorine concentration (0.95
mg/L) was calculated to be 12.3 L. These data indicate a chlorine demand in this water of
approximately 1.2 mg/L.
Iron was added to the raw water using a 4.8% ferric chloride solution. The ferric chloride was
fed with a chemical metering pump that was set to deliver approximately 2.2 mL/min (3.2
L/day), which would yield an iron addition of 2.8 mg/L as Fe. The pump calibration checks
showed the average fed rate was closer 1.8 mL/min (2.6 L/day). A total of 23.9 liters (6.3
gallons) of ferric chloride solution was used over the 14-day test to treat 204,870 gallons of raw
water. Based on the total amount of solution fed, the average concentration of ferric chloride
added to the raw water was calculated to be 1.5 mg/L. The measured feed water concentration
averaged 1.9 mg/L, and the raw water concentration averaged 0.47 mg/L. These data indicated
approximately 1.43 mg/L of iron addition, which was close to the calculated 1.5 mg/L fed based
on chemical use. It should be noted that the daily calibration average of 1.8 ml/min is higher
than the average iron feed rate based on the total volume of ferric chloride used over the duration
of the test. The reason for the higher rate reading on the pump calibration graduated tube is not
known, but may be due to the difference between pumping against the water supply pressure and
the atmospheric pressure used for calibration. The actual total volume measured for the entire
test is considered the most accurate data, because it balances with the measured iron
concentrations in the feed water and represents the entire pumping period rather than a five-
minute daily calibration period.
4.6 Other Operating Information
The KemLoop System was operated by the DWTS field staff during the 14-day verification
period. The system was found to be easy to operate and required little time for daily
maintenance. The field staff was on site for two to three hours per day. Most of the time on site
was spent performing ETV-related activities, including daily chemical analyses, flow checks,
calibrations, and so forth. In a normal operation, the inline pH meters and turbidimeters would
be used for system checks. The PLC records all of the flow data, pressure information,
backwash cycles, and so forth. Therefore, it would be anticipated that the time to check the
system on site would be minimal, possibly less than 30 minutes, except when chemical
feedstocks needed to be replenished or inline instruments calibrated. The PLC can be set up for
remote access, allowing main system parameters to be monitored without a site visit.
The chemical feed system used two chemical metering pumps, a 5-gallon plastic container for
the bleach solution, and a 15-gallon plastic container for the ferric chloride solution. The bleach
solution was made by diluting the purchased bleach solution with water at a ratio of one part
bleach to one part water. The purchased ferric chloride solution was also diluted prior to use at
one part ferric chloride to two parts water. An operator needs to periodically make the bleach
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and ferric chloride solutions and pour both feed solutions into the feed containers. Larger feed
containers could be used to reduce the frequency of chemical additions. For larger systems, the
containers could be larger and possibly used as the actual feed containers (totes, etc.).
The chemical meter pumps held the same stroke per minute settings throughout the test.
However, the calibration data and the measured concentration data for iron did seem to indicate
that the ferric chloride feed rate varied more than might be expected. The 95% confidence
interval for the feed water iron concentration was in the 1.1-2.1 mg/L range, after adjustment for
the raw water iron content. The chemical metering pumps were not paced based on flow rate. In
the ORCA system the flow rate is set to a constant rate, so a constant chemical pump feed rate
should give consistent feed water concentration.
The KemLoop System has an interface for connecting a computer to the PLC, which allows
reading and checking of current and historical data for all key operating parameters. The unit
also has manual readouts on the feed and filtrate flow rate; the pressures for feed, filtrate and
concentrate; and the inline pH meters and turbidimeters. The PLC readings were easy to see, but
did require an understanding of the PLC operating keys to display the readings. The laptop
computer supplied for the test was easier to use for checking systems flows, pressures, and so
forth
Backwash for this system is based on a preset time and backwash cycle. The backwash is also
set to initiate based on pressure differential across the filter (head loss) or turbidity differential
between the raw water and the filtrate. The entire backwash cycle is fully automated and
requires no operator intervention. The backwash source can either be raw (untreated) or treated
water. It is important that the source have sufficient capacity to deliver the required backwash
flow rate. ORCA specifications call for 75-100 gpm and a total volume of 500 gallons. The
measured flow rate for the test system was 45-62 gpm, and the volume averaged 220 gallons per
backwash. At the test site, the raw water intake line from the pressure tank was not large enough
to supply the needed flow rate. Therefore, a treated water holding tank was used to supply water
for the backwash pump.
The KemLoop System operated continuously during the verification test. There were no
unexpected shutdowns or equipment maintenance issues during the test, except for failure of the
inline pH meters. The feed water pH meter electrode broke at the beginning of the test. It would
have taken several days to obtain an electrode, and the unit would have to be shut down to
replace the electrode. Since there was no acid addition required for this test and daily pH
measurements were being made at the on-site laboratory set up by the DWTS field staff, it was
decided to continue the verification test without repairing the inline pH meters. This situation
demonstrates the importance of having critical spare parts available for common items, such as
pH electrodes, turbidity sensors, and so forth, in addition to the chemicals needed to treat the raw
water.
The verification test originally started on March 21, but was postponed to March 23 due to a leak
in the ferric chloride feed system. During the first night of testing, the chemical metering pump
fell off its base, and the inlet pipe broke. Ferric chloride spilled from the chemical feed tank.
The chemical feed pump was not inside of secondary containment, and the ferric chloride spilled
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out of the shipping container housing the unit and onto the concrete pad. It was noted that the
entire chemical feed system for both ferric chloride and bleach should be built within secondary
containment to avoid this problem. The pump mounting system used for the test system was not
the standard ORCA mounting, because this unit was built inside a shipping container to
accommodate the site conditions. ORCA indicated future systems would have secondary
containment. The ferric chloride was cleaned up and the test restarted on March 23.
Overall, the KemLoop System appears well suited to small- or medium-scale installations where
an operator is not present at all times. The system is automated, and all equipment appeared
sturdy and properly selected for the process. The PLC/PC system tied to an Internet connection
is recommended to allow operator monitoring from a remote location.
ORCA provides an O&M manual for each system installed at a site. The draft O&M manual for
a KemLoop System, presented in Appendix A, provides a good description of the system,
appropriate safety precautions, and detailed descriptions of operating procedures, capability and
operation of the computer control system, and specific instructions for utility operators. The
maintenance section of the manual includes some descriptions of required maintenance, but
refers the reader to the individual equipment literature supplied by the various pump and
instrument manufacturers. These manuals were provided in a notebook. The draft O&M manual
did not contain specific checklists for routine site visits. The manual is well organized and easy
to read. However, the draft needs to be revised and updated to incorporate missing items noted
in the draft. The addition of a troubleshooting section and operator routine checklists would be
helpful.
The O&M manual provides detailed information on the various modes that can be used for
operating the equipment. The modes are preprogrammed operating conditions that include filter
backwash triggers and the manner in which the PLC responds to various signals and alarms. The
PLC discussion is thorough, and the programming provides good flexibility for the operator.
The O&M manual also describes the tanks, piping, and filter units, with information on the
connections for each vessel. Instructions for items to check prior to start-up are included in the
descriptions.
As stated in the PSTP, the KemLoop System was evaluated for overall operability based on the
actual conditions observed during the verification test and on the capabilities of the system
equipment and control system. The KemLoop System was found to be easy to operate. It
provided all needed information and controls to operate the system, and flexibility for multiple
chemical feeds and adjustment of operating and backwash cycles.
The system design provides for multiple feed ports in the raw water feed line to add several
chemicals, including acid/caustic for pH control (not used in this application), coagulant (in this
case iron), and oxidants (bleach). In the test unit, the chemical feed pumps were not paced to
raw water flow. However, the raw feed rate was manually set by the operator, so unless there
was a wide variation in pressure at the raw water source, flow rate should be steady and matched
to the chemical feed rate. It would be helpful in a regular installation if the chemical feed pumps
were set up to be flow paced and automatically shut down if flow were interrupted. ORCA has
73
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indicated that the control of chemical feeds based on raw water flow can be provided. The
bleach chemical feed pump was stable throughout the test and did not need adjustment to
maintain the selected feed rate. The ferric chloride feed pump varied based on the calibration
checks performed, and the iron dose fluctuated between 1.1-2.1 mg/L based on the calculated
95% confidence interval of the iron concentrations. This part of the system may need close
attention during the first few weeks of operation to be sure the targeted dose is being delivered
consistently. The variation did not appear to affect arsenic removal in this application.
The system included inline pH and turbidimeters to monitor the raw and filtrate water, which
provided data to show that effective chemical feed rates were being delivered to the system. The
PLC/PC provided both real-time display of the pH and turbidity and historical data that could be
displayed in a trend plot for any time interval selected. The turbidity meters worked well during
the test. As stated earlier, the inline pH meters were not functioning during the verification test.
They appear to be standard units that should work in this application, if properly calibrated.
The KemLoop System includes a flow totalizer and flow rate meter for the filtrate water. The
system has pressure gauges on the feed and filtrate lines that provide pressure data for
monitoring pressure differential (head loss) across the filters. All of this information is recorded
and monitored by the PLC/PC and is available to the operator for review. Both real-time
readings and trend plots can be displayed on a PC. The system also monitors hours of operation
and can activate an alarm if any operating parameter is outside of preset "normal" operating
limits. The PLC/PC can be programmed to shut down the unit if turbidity, pH, or any other
operating parameter exceeds the preset acceptable limits.
The electrical use by the KemLoop System is primarily for the raw water pump (if required), the
backwash pump, the chemical feed pumps, and the PLC and instrumentation. The test system
used a 230 VAC, 1 Phase, 30-ampere electrical supply. The test system had two 1.5 hp
centrifugal pumps, one to provide raw water flow (not used in this application) and one for
backwash. The two chemical feed pumps were small units using approximately 150 watts each.
The PLC/PC power consumption was considered small. Based on one of the 1.5 hp pumps
running during backwash cycles for approximately 4 minutes, it is estimated that approximately
0.1 hp-hour of electrical power was used by this equipment. Unadjusted horsepower (not
adjusted for efficiency factor) is equal to 746 watts per hp. Therefore, it is estimated that
approximately 0.75 kilowatt-hr was used for the pump. The other equipment (chemical pumps
and PLC/PC) used an estimated 0.4 kilowatt-hr, bringing the total estimated electrical power use
to 0.5 kilowatt-hr. This use was only during the daily backwash cycle. The chemical feed system
and PLC were in operation continuously 24 hours per day.
For a system that requires a dedicated raw water pump, the 1.5 hp pump would run continuously,
assuming continuous system operation. In this case, a 1.5 hp pump would use approximately 1.1
kilowatt-hr. A system with a dedicated raw water pump, two chemical feed pumps, and a PLC
would use approximately 1.5 kilowatt-hr.
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4.7 Quality Assurance/Quality Control
As described in Task 6, Section 3.9.8, a structured QA/QC program was implemented as part of
this verification to ensure the quality of the data being collected. A QAPP was developed as part
of the PSTP and followed by the field staff and laboratory during the testing period. Careful
adherence to the established procedures ensured that the data presented in this report are sound,
defensible, and representative of the equipment performance.
4.7.1 Documentation
DWTS site operators recorded on-site data and calculations (e.g., calculating calibration flow
rates using the bucket and stop watch, and other similar routine calculations) in a field logbook
and prepared field log sheets. Daily measurements were recorded on specially prepared data log
sheets. The original logbook was stored on site, and copies were forwarded to the project
coordinator at NSF offices once per week during the verification test. The operating logbook
included calibration records for the field equipment used for on-site analyses. Copies of the
logbook, the daily data log sheets, and calibration log sheets are in Appendix B.
Data from the on-site laboratory and data log sheets were entered into Excel spreadsheets. These
spreadsheets were used to calculate various statistics (average, mean, standard deviation, etc.).
The data in the spreadsheets were proofread by the initial data entry person. NSF DWS Center
staff then checked 100% of the data entered into the spreadsheets to confirm the information was
correct. The spreadsheets are presented in Appendix D.
Samples collected and delivered to the NSF Chemistry Laboratory for analyses were tracked
using chain-of-custody forms. Each sample was assigned a location name, date, and time of
collection, and the parameters were written on the label. The laboratory reported the analytical
results using the NSF Chemistry Laboratory management system reports. These reports were
received and reviewed by the NSF DWS Center coordinator. These laboratory data were entered
into the data spreadsheets, corrected, and verified in the same manner as the field data. Lab
reports and chain-of-custody records are included in Appendix C.
4.7.2 Quality Audits
The NSF QA department performed on-site audits on March 24 (Day 1) and March 28, 2005
(Day 5) to review the field procedures, including the collection of operating data and
performance of on-site analytical methods. The PSTP requirements and QAPP were used as the
basis for the audit. The NSF QA auditor prepared an audit report. All deficiencies were
corrected immediately.
The NSF QA Department reviewed the Chemistry Laboratory analytical results for adherence to
the QA requirements for calibration, precision, and accuracy detailed in the project QAPP and
for compliance with the laboratory quality assurance requirements. The laboratory raw data
records (run logs, bench sheets, calibrations records, etc.) are maintained at NSF and are
available for review.
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4.7.3 Data Quality Indicators
The data quality indictors established for the ETV project and described in the QAPP included:
• Representativeness
• Accuracy
• Precision
• Completeness
4.7.3.1 Representativeness
Representativeness refers to the degree to which the data accurately and precisely represent the
conditions or characteristics of the parameter represented by the data. In this verification testing,
representativeness was ensured by executing consistent sample collection procedures in
accordance with established approved procedures, and following specific sample preservation,
packaging, and delivery procedures. Approved analytical methods were used to provide results
that represent the accurate and precise measurements of drinking water. For equipment
operating data, representativeness entailed collecting and documenting a sufficient quantity of
data during operation to be able to detect a change in operations. For most water treatment
processes involving total arsenic removal, detecting a +/- 10% change in an operating parameter
was sufficient. The primary operating parameters for this verification test were filtrate volume
treated per day and the related parameter raw water pressure. On two days, April 3 and 4, 2005,
the filtrate water volume was more than 10% below the target volume of 14,400 gallons, and the
raw water pressure dropped to 34-35 psi, slightly more than 10% below the 40 psi target. The
drop in pressure from the Center's pressure tank caused the lower pressure and the resultant drop
in raw water flow rate (equal to filtrate flow rate). There were no adjustments made, because
this pressure was dependent on the Center's pressure tank. The slightly lower filtrate volume for
these two days did not appear to affect treatment performance. Thus, these data were judged to
be representative and were included in the data set for the verification test.
4.7.3.2 Accuracy
On-Site Equipment Accuracy and Calibration
On-site equipment, including KemLoop System flow meters and DWTS on-site analytical
equipment, was tested for accuracy through regular calibration checks. Meters and gauges were
checked at the frequencies presented in Table 4-20. The calibration records for pH, turbidity,
total and free residual chlorine, and DO were recorded in the field calibration log (Appendix B).
All calibrations were performed at the frequency required. All calibration data were within the
specified QC objectives on all days analyses were performed.
The KemLoop System had a filtrate water flow rate and totalizer meter. The "bucket and
stopwatch" technique was used to determine the accuracy of the flow meters. Table 4-21 shows
the calibration data. All calibrations were within the defined objective of + 10%.
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Table 4-20. Field Instrument Calibration Schedule
Instrument
Calibration Method
Frequency
Acceptable
Accuracy
Flow Meters
Portable Turbidimeter
Portable pH/ISE Meter
with Combination pH/
Temperature Electrode
DO Meter
Thermometer (National Institute
of Standards and Technology
[NIST]-traceable)
Spectrophotometer
Volumetric "bucket & stop watch" Weekly
Secondary turbidity standards Daily
Primary turbidity standards Weekly
Three-point calibration using Daily
4.0, 7.0 and 10.0 buffers
Based on known air saturation Daily
concentrations of DO at the
measured air temperature
Calibration against NIST traceable Monthly
Chlorine check standard Daily
± 10%
N/A
±5%
N/A
+ 5%
+ 25%
N/A = Not Applicable.
Table 4-21. Filtrate Flow Meter Calibration Data
Calibration Flow Meter
Date Result (gpm) Reading (gpm)
3/31/05
4/06/05
10.2
10.4
10.0
10.3
One of the original objectives was to use the bench top turbidity readings to check the inline
turbidity meters for the raw and filtrate water. However, it became apparent that the inline
readings were always lower than the bench top readings. Both units were calibrated with
primary and secondary standards, but the inline unit always read lower. The explanation may be
that the cool samples tended to slightly fog the bench vials used to hold the sample, which would
give a higher turbidity readings. It is believed that the inline unit may provide the more accurate
data in this situation. Both the bench top and inline unit showed filtrate water was below 0.5
NTU on 13 out of 14 days, and both units showed high turbidity on one day, March 24.
Therefore, both units showed the filtrate had a low turbidity. In the case of the raw water, the
bench top unit showed a mean turbidity of 2.4 NTU, whereas the inline unit showed a mean
value of 0.60 NTU. This is a groundwater source and would be expected to have a low turbidity.
It is possible that, in addition to the effect of fogging in the bench top unit, iron present in the
raw water started to oxidize during the bench top test, thus increasing the turbidity of the sample.
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Laboratory Analyses
Accuracy for the laboratory analyses is quantified as the percent recovery of a parameter in a
sample to which a known quantity of that parameter was added. Equation 4-1 is used to
calculate accuracy:
Accuracy = Percent Recovery = 100 x [(Xknown - Xmeasured) ^ Xknown] (4-1)
where Xknown = known concentration of measured parameter
= measured concentration of parameter
Accuracy also incorporates calibration procedures and use of certified standards to ensure the
calibration curves and references for analysis are near the "true value." Accuracy of analytical
readings is measured through the use of spiked samples and lab control samples. The percent
recovery is calculated as a measure of the accuracy.
The QAPP and the NSF Chemistry Laboratory QA/QC requirements established the frequency
of spike sample analyses at 10% of the samples analyzed. Laboratory control samples (LCS) are
also run at a frequency of 10%. The recovery limits specified for the parameters in this
verification were 70-130% for laboratory- fortified samples and 85-1 15% for LCS. The NSF QA
department reviewed the laboratory records and found all analyses for all sample groups were
within the QC requirements for recovery. Calibration requirements were also achieved for all
analyses.
The arsenic speciation resin columns were tested to ensure proper separation and recovery of the
arsenic species. Each lot of the arsenic speciation resin was checked once against samples with
known concentrations of As (III) and As (V). This QC check assured that the resin was properly
prepared. The NSF Chemistry Laboratory maintained the documentation for the column checks.
4. 7.3.3 Precision
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 relative standard deviation
recorded from sample analyses was used to quantify sample precision. The percent relative
standard deviation was calculated using the equation presented as Equation 4-2 :
Percent Relative Standard Deviation = S(100) / Xaverage (4-2)
where: S = standard deviation
= the arithmetic mean of the recovery values
Standard Deviation is calculated in Equation 4-3 :
Standard Deviation = l& (Xi-XT (4-3)
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where: X; = the individual measured values
X = the arithmetic mean of the measured values
n = the number of determinations
Acceptable analytical precision for the verification test was set at a percent relative standard
deviation (RSD) for drinking water samples of 30%. Field duplicates were collected to
incorporate both sampling and analytical variation to measure overall precision against this
objective. The laboratory precision for the methods selected was tighter than the 30% overall
requirement, generally set at 20% based on the standard NSF Chemistry Laboratory method
performance.
Field Duplicates
Field duplicates were collected for all analyses (field lab and analytical laboratory) to monitor
overall precision. The field duplicates included samples for all three sample locations: raw, feed,
and filtrate water.
Tables 4-22 and 4-23 summarize the results for the field duplicate samples. The precision for
analyses performed in the laboratory, as measured by these field duplicates, met the overall QC
objective of 30% RSD, except for one manganese sample. The filtrate sample for March 24 was
flagged as having an analysis problem. The results of 180 and 33 |ig/L had very poor precision
and were not typical of the manganese in this water (10-20 |ig/L). The lab records were checked,
but no apparent reasons for the poor precision and high concentration were determined. These
data were flagged as outliers in the data set.
The field analyses data for field duplicates were good for pH and one set of free and total
residual chlorine data. However, the second set of duplicates on April 5 showed poor precision
for both free and total residual chlorine in the feed and filtrate samples. The actual sample
results (replicate 1) were similar to previous analyses and within the expected concentrations
based on chemical feed to the system. However, the field duplicate samples showed a low
concentration of free and total residual chlorine. It is not known why the second field sample
was low for both sampling locations. A switch could have occurred between samples or sample
labels. Turbidity precision was poor for the one set of replicates collected. As noted previously
in this report, the bench top turbidity readings were high compared to the inline analyzers. The
problems with water temperature, fogging, and iron oxidation were the most likely cause of the
poor precision and possible bias in the data.
Laboratory Analytical Duplicates
The NSF Chemistry Laboratory precision was monitored during the verifications test in
accordance with QAPP and the NSF quality assurance program. Laboratory duplicates were
analyzed at 10% frequency of samples analyzed. The NSF QA department reviewed the
precision information and determined that the laboratory data met QC precision requirements.
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4.7.3.4 Method Blanks
The laboratory included method blanks as part of the standard analysis procedures. Method
blanks were analyzed in accordance with the approved methods. The NSF QA department
reviewed the laboratory data and found the method blanks to be acceptable. No data were
flagged as having been affected by method blank results.
Table 4-22. Precision Data - Field Duplicates for Laboratory Parameters
Total Arsenic (jig/L)
Date
Raw Water
Feed Water
Filtrate
3/24/05
4/02/05
4/05/05
Repl
28
19
20
Rep 2
28
19
20
%RSD
0
0
0
Repl
24
20
19
Rep 2
23
20
20
%RSD
3.0
0
3.6
Repl
12
<10
<10
Rep 2
12
<1
1
%RSD
0
NC
NC
Parameter
Dissolved Arsenic (>ig/L)
Date
3/24/05
Repl
23
Raw Water
Rep 2
22
%RSD
3.1
Repl
<1
Feed Water
Rep 2
<1
%RSD
NC
Repl
<1
Filtrate
Rep 2
<1
%RSD
NC
Arsenic III (jig/L)
Date
3/24/05
Repl
21
Raw Water
Rep 2
21
%RSD
0
Repl
<1
Feed Water
Rep 2
<1
Alkalinity (mg/L as
Date
3/24/05
Repl
250
Raw Water
Rep 2
260
%RSD
2.77
Repl
260
Feed Water
Rep 2
240
%RSD
NC
Repl
<1
CaC03)
%RSD
5.66
Repl
260
Filtrate
Rep 2
<1
Filtrate
Rep 2
250
%RSD
NC
%RSD
2.77
Iron (mg/L)
Date
3/24/05
4/02/05
Repl
0.86
0.36
Raw Water
Rep 2
0.84
0.36
%RSD
1.7
0
Repl
4.5
1.7
Feed Water
Rep 2
4.4
1.7
%RSD
1.6
0
Repl
1.7
O.02
Filtrate
Rep 2
1.8
O.02
%RSD
4.0
NC
Other Parameters (3/24/05)
Raw Water
Feed Water
Filtrate
Chloride (mg/L)
Sulfate (mg/L)
Calcium (mg/L)
Magnesium (mg/L)
Manganese (|ig/L)
Fluoride (mg/L)
TOC (mg/L
Repl
12
17
76
23
18
0.4
0.6
Rep 2
12
18
75
23
18
0.5
0.6
%RSD
0
4.0
0.94
0
0
16
0
Repl
19
17
—
—
...
—
—
Rep 2
20
18
—
—
...
—
—
%RSD
3.6
4.0
—
—
...
—
—
Repl
19
18
75
23
180
0.5
0.6
Rep 2
19
18
74
23
33
0.5
0.6
%RSD
0.0
0
0.95
0
98
0
0
NC = Not Calculated.
"—" = Not required or scheduled for analysis.
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Table 4-23. Precision Data - Field Duplicates for Field Parameters
PH
Date
Raw Water
Feed Water
Filtrate
3/30/05
4/05/05
Repl
7.27
7.20
Rep 2
7.40
7.20
%RSD
1.25
0
Repl
7.31
7.19
Rep 2
7.34
7.25
%RSD
0.29
0.59
Repl
7.38
7.23
Rep 2
7.40
7.24
%RSD
0.19
0.10
Turbidi ty Bench Top (NTU)
Date
4/05/05
Repl
1.7
Raw Water
Rep 2
2.5
%RSD
27
Repl
3.1
Feed Water
Rep 2
1.8
%RSD
38
Repl
0.20
Filtrate
Rep 2
0.55
%RSD
66
Free Residual Chlorine (mg/L)
Date
Raw Water
Feed Water
Filtrate
3/30/05
4/05/05
Repl
0.05
O.05
Rep 2
0.05
O.05
%RSD
NC
NC
Repl
0.10
0.38
Rep 2
0.12
0.07
%RSD
13
97
Repl
0.05
0.34
Rep 2
0.05
0.06
%RSD
NC
99
Total Residual Chlorine (mg/L)
Date
Raw Water
Feed Water
Filtrate
3/30/05
4/05/05
Repl
O.05
0.05
Rep 2
O.05
0.05
%RSD
NC
NC
Repl
1.10
0.97
Rep 2
1.07
0.13
%RSD
1.96
108
Repl
1.08
0.98
Rep 2
1.11
0.38
%RSD
1.94
62.4
NC = Not Calculated.
4.7.3.5 Completeness
Completeness is defined as the following (Equation 4-4) for all measurements:
%C = (V/T) X 100 (4-4)
where: %C = percent completeness
V = number of measurements judged valid
T = total number of measurements
Completeness refers to the amount of valid, acceptable data collected from a measurement
process compared to the amount expected to be obtained.
The completeness objective for data generated during this verification test was based on the
number of samples collected and analyzed for each parameter and/or method. A completeness
objective of 90% applied to: total arsenic, iron, pH, daily bench top turbidity, residual chlorine,
and TSS. Completeness criteria also applied to the following operating parameters: filtrate flow
rate, pressure differential across the filter, and volume and flow rate measurements for backwash
water. Samples for all of the critical parameters (total arsenic, iron, pH, daily bench top
turbidity, residual chlorine for raw, feed, and filtrate water, and backwash water TSS) were
collected and analyzed at the frequency specified for the verification test. All data were usable
except for one suspect iron result and free residual chlorine value. Table 4-24 provides a
summary of the completeness results for the verification test.
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Table 4-24. Completeness Results
Percent
Parameter Completeness
Comment
Filtrate Flow Rate
Pressure Feed and Filtrate
Chemicals Added
Volume and Rate of
Backwash
Total Arsenic
Iron
PH
Bench top Turbidity
Total Residual Chlorine
Free Residual Chlorine
Backwash TSS
100 All required daily measurements recorded.
100 All required daily measurements recorded.
100 Total amount of chemicals used recorded.
79 All required volume and time measurements recorded.
A few tank depth measurements missed, but not critical
to monitoring backwash frequency because it was set
to once per day by the PLC.
100 All scheduled samples and analyses completed. One
raw water sample flagged as possible outlier. One set
of speciation data was flagged, but there were a total of
four sets of speciation data versus the two required.
Several samples had matrix interferences.
100 All scheduled samples and analyses completed.
100 All required daily measurements recorded.
100 All required daily measurements recorded. Problems
with raw turbidity measurements noted in the report
discussion.
100 All required daily measurements recorded.
99 All required daily measurements recorded. One sample
out of 87 was flagged as an outlier.
100 All scheduled samples and analyses completed.
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Chapter 5
References
EPA/NSF ETV Protocol for Equipment Verification Testing for Arsenic Removal, U.S. EPA/NSF
International. September 2003.
Hack Water Analysis Handbook, Hach Company, Loveland, Colorado. 1992.
Product Specific Test Plan for the ORCA Water Technologies KemLoop 1000 Coagulation and
Filtration Water Treatment System for Arsenic Removal from Drinking Water. Scherger
Associates and NSF International. February 2005.
Quality Criteria For Water, U.S. EPA. July 1976.
Standard Methods for the Examination of Water and Wastewater, 20th edition, APHA, AWWA,
and WEF, Washington D.C. 1999.
U.S. EPA Drinking Water Methods for Chemical Parameters. EPA Office of Ground Water and
Drinking Water. EPA Methods are available from the National Technical Information Service
(NTIS).
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