EPA/600/R-14/029S
May 2014
THE ENVIRONMENTAL TECHNOLOGY VERIFICATION
PROGRAM ^
//
wEFA
ETV
U.S. Environmental Protection Agency
NSF International
ETV Verification Statement
TECHNOLOGY TYPE: BIOLOGICAL TREATMENT
APPLICATION: ARSENIC, AMMONIA, IRON AND MANGANESE
REDUCTION
PRODUCT NAME: CHEMILES NCL SERIES SYSTEM
VENDOR: NAGAOKA INTERNATIONAL CORPORATION
ADDRESS: 6-1NAGISA-CHO
IZUMIOTSU-CITY
OSAKA, JAPAN 595-0055
PHONE: 81 725 21 5750
WEBSITE: WWW.NAGAOKA JAPAN. CO. JP
EMAIL: K-YAMADA@NAGAOKAJAPAN.CO.JP
NSF International (NSF) manages the Drinking Water Systems (DWS) Center under the U.S.
Environmental Protection Agency's (EPA) Environmental Technology Verification (ETV) Program. The
DWS Center recently evaluated the performance of the Nagaoka International Corporation CHEMILES
NCL Series system. NSF performed the laboratory analyses at its Ann Arbor, MI location, and the test
site was located at the Clark Public Utilities Bridge Road Water Treatment Plant (also known as the
Hayes Road Well)- near Woodland, Washington in Clark County, USA. CH2MHill under contract with
NSF and whose quality was overseen by NSF, performed all field monitoring and sample collection.
EPA created the ETV Program to facilitate the deployment of innovative or improved environmental
technologies through performance verification and dissemination of information. The ETV Program's
goal is to further environmental protection by accelerating the acceptance and use of improved and more
cost-effective technologies. ETV seeks to achieve this goal by providing high quality, peer-reviewed data
on technology performance to those involved in the design, distribution, permitting, purchase, and use of
environmental technologies.
ETV works in partnership with recognized standards and testing organizations, stakeholder groups
(consisting of buyers, vendor organizations, and permitters), and with the full participation of individual
technology developers. The program evaluates the performance of innovative technologies by developing
test plans that are responsive to the needs of stakeholders, conducting field or laboratory tests (as
appropriate), collecting and analyzing data, and preparing peer-reviewed reports. All evaluations are
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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.
ABSTRACT
The Nagaoka International Corporation CHEMILES NCL Series system was tested to verify its
performance for the reduction of multiple contaminants including: arsenic, ammonia, iron, and
manganese. The objectives of this verification, as operated under the conditions at the test site under real
world conditions, were to evaluate:
• Impacts on performance of any variations in feed water quality or process variation;
• Logistical, human, and other resources necessary to operate the equipment;
• Reliability, ruggedness, ranges of usefulness, and ease of operation of the equipment.
Methods followed the approved test quality assurance project plan.
The CHEMILES NCL Series system pilot plant was easy to operate and maintain. The unit was
completely automated and required only minimal maintenance. The programmable logic controller
(PLC) monitored flow in the system, operated pumps and valves and conducted backwashing.
The water produced was normalized te a 24-hour day and averaged 6,527 gallons (gal), with a range of
5,367 to 6,698 gal.
Results include arsenic, iron, manganese, and ammonia reduction for the raw and treated water. Also
included with the ammonia results are the nitrate and nitrite results^ since the system oxidizes ammonia to
nitrate. Arsenic was detected below the reporting limit for all treated water samples, except for one
sample during the intensive sampling period with arsenic reported at 0.002 mg/L. Nagaoka's target
performance criterion for ammonia was 75% reduction. The treated water ammonia concentrations ranged
from 0.03 to 0.19 mg/L, with a mean of 0.05 mg/L. The 75% reduction performance level was achieved
for all weekly raw/treated sample pairs, except for three pairs. All weekly raw and treated water samples
had nitrite below the laboratory reporting limit of 0.02 mg/L as N. Levels in treated water for nitrate were
below the EPA MCL of 1 mg/L as N.
Iron and manganese are regulated secondary drinking water contaminants. The reduction of these
contaminants is to improve the aesthetic quality of the finished produced water. All treated water iron
measurements were below the EPA secondary maximum contaminant level (MCL) of 0.3 mg/L. The
treated water iron concentrations ranged from 0.02 to 0.18 mg/L, with a mean of 0.05. The monitoring
period for manganese removal was delayed to allow more time for the manganese oxidizing bacteria to
cultivate on the filtration media. During the May 2013 intensive sampling, in the first period without pH
adjustment, six of the seven treated water daily manganese samples results were below the MCL of 0.05
mg/L. Subsequently , the second period showed pH adjustment can be effective on higher raw water
manganese contaminated levels. More detail is provided in the final ETV report.
A sample of the backwash was collected and analyzed following the EPA Toxicity Characteristic
Leaching Procedure (TCLP) and the California Waste Extraction Test (CAWET) requirements. 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).
TECHNOLOGY DESCRIPTION
The vendor provided the following description, which was not verified: The CHEMILES NCL Series
system is a self-contained, chemical-free system designed for treatment of groundwater. The system is a
column design, intended for outdoor placement. The system does not include a chemical feed pump, but
it does include a treated water pump and a backwash pump. The treatment column contains a sand filter
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medium, with a support gravel layer at the base. The system must be allowed to ripen for three to six
months, to allow autotrophic bacteria to colonize the sand filter medium.
Raw water is introduced into the top of the column through a proprietary oxidation nozzle of Nagaoka
International Corporation (Nagaoka). The nozzle utilizes the "Venturi effect" to introduce air which
reduces fluid pressure when the water flows through a constriction. Air is induced through a hole in the
nozzle near the constriction and causes the air and water to be mixed.
The scientific theory of the CHEMILES system is that the oxidation nozzle increases the dissolved
oxygen (DO) level of the raw water, causing soluble ferrous iron to oxidize to insoluble ferric iron, and
arsenic (III) to oxidize to arsenic (V). The sand filter medium becomes coated with ferric oxi-hydroxide
which acts as a catalyst to oxidize and retain a portion of the iron. The bacterium on the filter medium
oxidizes any remaining ferrous iron to ferric iron, and also ammonia to nitrate and soluble manganese to
insoluble manganese dioxide. The ferric iron and manganese dioxide are retained by the filter medium.
There are two types of backwashes for the CHEMILES system - "P" backwashes and "W" backwashes.
The P backwashes are partial backwashes, and W backwashes are whole-system backwashes. The P
backwashes occur several times per day, while the W backwash usually occurs once per day or less
frequently.
The P backwash just backwashes the upper filtration zone where most of the arsenic and iron precipitate
is retained. The P backwash utilizes Nagaoka's proprietary rotating surface washing nozzles to assist in
the backwash process. This approach minimizes disturbances of the biological active lower treatment
zone.
VERIFICATION TESTING DESCRIPTION
Test Site and Equipment
The test site is the Clark Public Utilities Bridge Road Water Treatment Plant (also known as the Hayes
Road Well), located near Woodland, Washington in Clark County, USA. The site is only about 200 feet
away from the Lewis River, but it is not classified as ground water under the influence of surface water.
The site has an 8-inch diameter well with a submersible pump rated at 50 gallons per minute (gpm). The
plant is not continuously manned and is only operated periodically, depending on the level in the finished
water reservoir. The treatment plant includes manganese greensand filtration to remove iron, manganese,
and arsenic. For the verification test, a separate five gallon per minute (5 gpm) pump was installed in the
well casing to provide a dedicated supply to the pilot unit.
Methods and Procedures
An ETV Test Quality Assurance Plan (TQAP) was prepared for the CHEMILES NCL Series system
verification test in accordance with the ETV EPA/NSF Protocol for Equipment Verification Testing for
Arsenic Removal (September 2003). This protocol was used for the aspects of testing related to removal
of arsenic, iron, and manganese. There is no ETV Protocol for ammonia reduction so best available
professional judgment was used for the testing aspects related to this contaminant. More detail is
described in the final report and TQAP.
VERIFICATION OF PERFORMANCE
System Operation
The operational data included production of treated water, headless, and backwash flow rates. The pilot
unit produced treated water for approximately 23 hours per day. The water production, normalized to a
24-hour day, averaged 6,527 gal, with a range of 5,637 to 6,698 gal. For 47 days of headless
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measurements, the average headless recovery was 257 mm of water, with a range of 52 to 904 mm. The
mean backwash flow was 5.19 gpm, with a range of 4.92 to 10.67 gpm.
A review of the ability and ease of operation was evaluated by CH2MHill. The unit was completely
automated and required only minimal maintenance. Initially, the unit required some process
modifications, but once they were adjusted, very little adjustment was required thereafter. Because the
pilot filter was quite tall, an enclosed structure with ladder steps and access platforms was provided.
The pilot system is controlled by a PLC. The PLC monitored flow in the system, operated pumps and
valves and conducted backwashing. The Operation and Maintenance manual provided by Nagaoka
accurately described the PLC set points, and operators were able to change the set-points when requested
by Nagaoka. The pilot system could be improved by adding a differential pressure recording device
across the filter and incorporating all of the flow data into the PLC. A data logger would also be useful to
allow evaluation of data on a more frequent basis.
Infrequent maintenance included cleaning the aeration nozzles. Spare aeration nozzles were provided.
Over the testing period, the aeration nozzle only required replacement and cleaning one time. The
CHEMILES system uses three pumps for operation: a raw water pump, a treated water pump, and a
backwash pump. Based on an estimated pump efficiency of 90%, these three pumps consume
approximately 29.5 kW/day.
Test Results
Results include arsenic, iron, manganese, ammonia, nitrite and nitrate reduction for the raw and treated
water.
Arsenic
The historical water quality data suggested that the arsenic concentration in the raw water ranged from 15
to 36 ug/L. However, this was not the case at any time during the verification test. The arsenic level
reached as high as 0.020 mg/L during the March 48-hour intensive sampling period, but most of the time
it was below the EPA MCL of 0.010 mg/L. The statistical analysis of the weekly samples shows a mean
raw water arsenic concentration of 0.008 mg/L for the test, with a range of <0.002 to 0.014 mg/L. There
were two weeks when the raw water arsenic level was below the laboratory reporting limit of 0.002 mg/L.
Arsenic was below the reporting limit for all treated water samples, including all of those for the March
320-hour daily and 48-hour intensive sampling periods, except for one sample during the intensive
sampling period with arsenic reported at 0.002 mg/L.
Figure V-l. ETV Test results summary: Arsenic Removal (November 7th, 2012 ~ May 1st, 2013)
-Raw Water -•-Treated Water EPA regulated
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Ammonia, Nitrite and Nitrate
Ammonia in the raw water for the weekly samples ranged from 0.07 to 0.71 mg/L as N, with a mean of
0.40 mg/L. Ammonia in the treated water ranged from 0.03 to 0.19 mg/L as N, with a mean of 0.05
mg/L. Nagaoka's target performance criterion for ammonia was 75% reduction. The 75% reduction
performance level was achieved for all weekly raw/treated sample pairs, except three. The first pair was
that for November 21 and, in this instance, 75% reduction was not achieved because the raw
concentration was at the minimum of 0.07 mg/L measured for the entire test. The treated water level was
less than the laboratory reporting limit of 0.03 mg/L, so the low percent reduction was simply a function
of the low raw water concentration and the analytical method reporting limit. The other two sample pairs
with less than 75% reduction corresponded to spikes in the raw water ammonia concentration on January
23 and March 12. All weekly raw and treated water samples had nitrite below the laboratory reporting
limit of 0.02 mg/L as N. Levels in treated water for nitrate were below the EPA MCL of 1 mg/L as N.
Iron and Manganese
Iron and manganese are regulated secondary drinking water contaminants. The reduction of these
contaminants is to improve the aesthetic quality of the finished produced water. The raw water iron
concentrations varied widely during the test, just as the ammonia levels did, ranging from 2.0 to 15 mg/L,
with a mean of 9.4 mg/L. All treated water iron measurements were below the EPA secondary MCL of
0.3 mg/L. The treated water iron concentrations ranged from 0.02 to 0.18 mg/L, with a mean of 0.05. On
March 27, the raw water pH was raised with NaOH to try to improve the biologically mediated
manganese treatment. During this period, the treated water iron level rose to 0.40 mg/L on March 27, and
0.62 mg/L on April 3. The pH adjustment was stopped on April 8, and the treated water iron level was
measured at 0.03 mg/L on April 11.
The monitoring period for manganese removal was delayed until January 2013 to allow more time for the
manganese oxidizing bacteria to grow on the filtration media. The verification testing period was
extended into May of 2013 to allow for a second 320-hour daily sampling and 48-hour intensive sampling
periods focusing only on manganese reduction.
The weekly sample raw water manganese levels ranged from 0.13 to 0.32 mg/L, with a mean of 0.21
mg/L. The treated water levels ranged from 0.02 to 0.28 mg/L, with a mean of 0.11 mg/L. Of the fifteen
treated water weekly manganese sample results, only two samples were below the EPA secondary MCL
of 0.05 mg/L. Consequently, more time was allowed for the adjustment of the bacteria associated with
manganese treatment.
The May 320-hour daily sampling period for manganese is divided into several periods where pH
adjustment was used to enhance reduction. During May 10 to May 16, the pH of the raw water was not
raised, with a range of 6.62 to 6.69. From May 17 to May 23, the mean feed water pH after NaOH
addition was 7.03, with a range of 6.85 to 7.28. From May 10 to May 16, the raw water manganese
concentration ranged from 0.09 to 0.19 mg/L, with a mean of 0.14 mg/L. For the second week, from May
17 to May 23, the raw water manganese concentration was higher, ranging from 0.21 to 0.32 mg/L, with a
mean of 0.25 mg/L. Likewise, the treated water manganese concentrations were lower the first week than
the second week. From May 10 to May 16 the treated water manganese ranged from 0.03 to 0.07 mg/L,
with a mean of 0.04 mg/L. From May 18 to May 23, the treated water manganese ranged from 0.02 to
0.12 mg/L, with a mean of 0.06 mg/L. For this second week, the two lowest manganese measurements
were on the 22nd and 23rd, at 0.02 and 0.04 mg/L, respectively, indicating that perhaps pH adjustment
takes a few days to affect the treated water levels of manganese.
Other Water Quality Parameters
The pH of the raw water averaged 6.39 over the verification testing period, with a minimum of 6.17 and a
maximum of 6.57. Aeration of the raw water for treatment raised the pH to a mean of 6.68, with a range
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of 6.55 to 6.80. The pH of the treated water was slightly lower, with a mean of 6.46 and a range of 6.36
to 6.54. The raw water temperature was steady throughout the verification test, ranging from 1 1 .9 to 14.2
The DO of the raw water ranged from 2.97 to 4.16 mg/L, with a mean of 3.49 mg/L. Aeration of the
water raised the DO level to an average of 9.77 mg/L (range 7.61 to 11.31). Passage of the water through
the media column consumed oxygen, as would be expected for a biological treatment process. The DO of
the treated water averaged 6.51 mg/L (range 3.62 to 8.85).
The turbidity of the raw water was low, at 0.09 to 0.88 NTU, with a mean of 0.33 NTU. The treatment
process raised the turbidity somewhat, to a range of 0.17 to 3.23 NTU (mean of 0.80).
The CHEMILES system treated water HPC counts were below 10 CFU/mL, except for one count of 149.
For most raw/treated sample pairs, the raw water count was 1, or <1 CFU/mL, so the treatment process
did contribute a small amount of HPC to the water but not to a degree warranting any concern about
hitting the EPA MCL of 500 CFU/mL
Backwash Waste
The backwash waste was sampled and analyzed. Immediately following a backwash event, samples were
collected from the backwash collection vessel. The backwash waste was enriched in arsenic, iron,
manganese, and TSS, as would be expected, given the removal of contaminants as measured in the treated
water. The CHEMILES System produced an average daily volume of 6,527 gal, and generated an
average backwash volume of 150 gpd. Analysis of the filter media by Nagaoka after the test ended
revealed that the filter media particle sizes had increased, indicating the backwashes did not fully remove
the accumulated contaminants from the filter media particles.
If solid separation were required before the backwash waste could be discharged, the solids would need to
be sent to a landfill for disposal. A sample of the backwash was collected and analyzed following the
EPA TCLP and the CAWET requirements. 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).
QUALITY ASSURANCE/QUALITY CONTROL
The NSF QA Department performed a QA review of the analytical data. An audit was performed on
December 5, 2013. As a result of the audit, certain biological samples and on-site measurements were
deemed not to have met data quality criteria and thus were excluded from the analysis of results.
However, the audit found that samples of critical parameters like arsenic and ammonia were deemed
acceptable. A complete description of the QA/QC procedures is provided in the verification report.
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Original signed by Cynthia Sonich-Mullin on
04/09/2014
Original signed
04/07/2014
by David Purkiss on
Cynthia Sonich-Mullin
Director
Date
David Purkiss
Water Systems General Manager
Date
National Risk Management Research
Laboratory
Office of Research and Development
United States Environmental Protection
Agency
NSF International
NOTICE: Verifications are based on an evaluation of technology performance under specific,
predetermined criteria and the appropriate quality assurance procedures. EPA makes 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 test protocol, the verification statement, and the verification report (NSF report #
NSF 10/33/EPADWCTR) are available from the following sources:
1. ETV Drinking Water Systems Center Manager (order hard copy)
NSF International
P.O. Box 130140
Ann Arbor, Michigan 48113-0140
2. Electronic PDF copy
NSF web site: http://www.nsf.org/info/etv
EPA web site: https://www.epa.gov/etv
NSF 13/38/EPADWCTR
The accompanying notice is an integral part of this verification statement.
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