THE ENVIRONMENTAL TECHNOLOGY VERIFICATION

PROGRAM

U.S. Environmental NSF International 

Protection Agency 

ETV Joint Verification Statement 

TECHNOLOGY TYPE: BIOLOGICAL WASTEWATER TREATMENT – 

NITRIFICATION AND DENITRIFICATION FOR 

NITROGEN REDUCTION 

APPLICATION: REDUCTION OF NITROGEN IN DOMESTIC 

WASTEWATER FROM INDIVIDUAL RESIDENTIAL 

HOMES 

TECHNOLOGY NAME: BIOCLERETM MODEL 16/12 

COMPANY: AQUAPOINT, INC. 

ADDRESS: 241 DUCHAINE BLVD. PHONE: (508) 998-7577 

NEW BEDFORD, MA 02745 FAX: (508) 998-7177 

WEB SITE: http://www.aquapoint.com 

EMAIL: Aquapoint@aquapoint.com 

NSF International (NSF) operates the Water Quality Protection Center (WQPC) under the U.S. 

Environmental Protection Agency’s (EPA) Environmental Technology Verification (ETV) Program. The 

WQPC evaluated the performance of a fixed film trickling filter biological treatment system for nitrogen 

removal for residential homes. This verification statement provides a summary of the test results for the 

Aquapoint, Inc. BioclereTM Model 16/12 system. The Barnstable County (Massachusetts) Department of 

Health and the Environment (BCDHE) performed the verification testing. 

The EPA created the Environmental Technology Verification (ETV) Program to facilitate 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 substantially 

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 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 

verifiable quality are generated and that the results are defensible. 

ABSTRACT 

Verification testing of the Aquapoint, Inc. (AQP) BioclereTM Model 16/12 was conducted over a thirteen 

month period at the Massachusetts Alternative Septic System Test Center (MASSTC), located at Otis Air 

National Guard Base in Bourne, Massachusetts. Sanitary sewerage from the base residential housing was 

used for the testing. An eight-week startup period preceded the verification test to provide time for the 

development of an acclimated biological growth in the BioclereTM system. The verification test included 

monthly sampling of the influent and effluent wastewater, and five test sequences designed to test the unit 

response to differing load conditions and power failure. The BioclereTM system proved capable of 

removing ammonia nitrogen in the aerobic unit and nitrate in the anaerobic/anoxic primary tank. The 

influent total nitrogen (TN), as measured by the TKN, averaged 37 mg/L with a median of 38 mg/L. The 

effluent TN average 16 mg/L over the verification period, with a median concentration of 14 mg/L, which 

included an average TKN concentration of 10 mg/L and a median concentration of 6.3 mg/L. The system 

operating conditions (pump and timer settings) remained constant during the test. Only routine 

maintenance and system checks were performed for most of the test, except when a nozzle -plugging 

problem occurred. The plugged nozzles impacted treatment performance, but performance improved 

quickly once they were cleared. 

TECHNOLOGY DESCRIPTION 

The AQP, Inc. BioclereTM Model 16/12 uses a fixed film trickling filter for wastewater treatment. A 

complete treatment system has two stages of treatment. The first stage of treatment occurs in the primary 

tank (a 1,000 gallon single compartment septic tank) in which the solids are settled and partially digested. 

Septic tank effluent flows by gravity to the BioclereTM unit, which is a separate system that provides 

secondary wastewater treatment. Microorganisms present in the wastewater attach to the BioclereTM 

proprietary plastic filter media, and use the nutrients and organic materials provided by the constant 

supply of fresh wastewater to form new cell mass. The open spaces within the media allow air to freely 

pass through, providing oxygen to support the microorganisms. 

The system has a recycle line for pumping of recycled solids from the BioclereTM clarifier section (located 

below the plastic media) back to the primary tank. The pump operated for 1.5 minutes every 2.5 hours 

during the test, controlling the recycle rate to the primary tank. A dosing pump, set to run on a 3 minutes 

on/5 minute off cycle, circulated treated effluent from the clarifier section back the top of the unit, where 

the wastewater is sprayed over the media using a manifold and nozzle system. Air (oxygen) is supplied to 

the BioclereTM by a fan located on the top of the unit, which runs continuously. 

The BioclereTM system is designed to remove total nitrogen from the wastewater by nitrification and 

denitrification. Nitrification occurs in the aerobic BioclereTM unit, where ammonia nitrogen is converted 

to nitrite and nitrate (predominately nitrate). Denitrification occurs in the anaerobic/anoxic primary tanks, 

where the nitrite/nitrate is converted to nitrogen. The verification testing was performed using a full scale, 

commercially available unit, which was received as a self-contained system ready for installation. 

VERIFICATION TESTING DESCRIPTION 

Test Site 

The MASSTC site, initially funded by the State of Massachusetts and operated by BCDHE, is located at 

the Otis Air National Guard Base in Bourne, Massachusetts. The site uses domestic wastewater from the 

base residential housing and sanitary wastewater from other military buildings for use in testing. A 

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chamber located in the main sewer line upstream of the base wastewater treatment facility provides a 

location to obtain untreated wastewater. The raw wastewater, after passing through a one-inch bar screen, 

is pumped to a dosing channel at the test site. This channel is equipped with four recirculation pumps, 

which are spaced along the channel length to ensure mixing such that the wastewater is of similar quality 

at all locations along the channel. Wastewater is dosed to the test unit using a pump submerged in the 

dosing channel. A programmable logic controller (PLC) is used to control the pumps and the dosing 

sequence or cycle. 

Methods and Procedures 

All methods and procedures followed the ETV Protocol for Verification of Residential Wastewater 

Treatment Technologies for Nutrient Reduction, dated November 2000. The BioclereTM was installed by a 

contractor, in conjunction with the BCDHE support team in June 1999 as part of an earlier test program. 

The unit was installed in accordance with the Operations and Maintenance Manual supplied by AQP. In 

order to prepare for ETV testing, the entire BioclereTM system was emptied of wastewater and cleaned. 

Solids were removed from the primary tank and the clarifier section of the BioclereTM filter unit. All 

pumps, lines, and associated equipment were cleaned. The filter media was repeatedly flushed and solids 

removed from the bottom of the unit. Clean water was recirculated to further clean the media and lines. 

The entire unit was then drained and remained off until the startup period. 

In early January 2001, fresh water was added to the unit and the system was cycled for several days to 

make sure the unit was operating properly, the dosing pumps were calibrated, and the PLC was working 

properly. An eight-week startup period, following the startup procedures in the AQP Technical Manual, 

allowed the biological community to become established and allowed the operating conditions to be 

monitored. Startup of the cleaned BioclereTM system began on January 15, 2001, when the primary tank 

was filled approximately two thirds (2/3) full with clean water and one third (1/3) with raw wastewater 

from the dosing channel. The dosing sequence was then started, with the unit’s pumps and timers on the 

factory default settings. 

The system was monitored during the startup period through visual observation, routine calibration of the 

dosing system, and collection of influent and effluent samples. Six sets of samples were collected for 

analysis. Influent samples were analyzed for pH, alkalinity, temperature, BOD5, TKN, NH3, and TSS. The 

effluent was analyzed for pH, alkalinity, temperature, CBOD5, TKN, NH3, TSS, dissolved oxygen, NO2, 

and NO3. 

The verification test consisted of a thirteen-month test period, incorporating five sequences with varying 

stress conditions simulating real household conditions. The five stress sequences were performed at twomonth intervals, and included washday, working parent, low loading, power failure and vacation test 

sequences. Monitoring for nitrogen reduction was accomplished by measurement of nitrogen species 

(TKN, NH3, NO2, NO3). Biochemical (BOD5) and carbonaceous biochemical oxygen demand (CBOD5) 

and other basic parameters (pH, alkalinity, TSS, temperature) were monitored to provide information on 

overall system treatment performance. Operational characteristics, such as electric use, residuals 

generation, labor to perform maintenance, maintenance tasks, durability of the hardware, and noise and 

odor production, were also monitored. 

The BioclereTM system has a design capacity of 400 gallons per day. The verification test was designed to 

load the system at design capacity (± 10 percent) for the entire thirteen-month test, except during the low 

load and vacation stress tests. The BioclereTM system was dosed 15 times per day with approximately 26­

27 gallons of wastewater per dose. The unit received five doses in the morning, four doses mid-day, and 

six doses in the evening. The dosing volume was controlled by adjusting the pump run time for each 

cycle, based on twice weekly pump calibrations. 

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The sampling schedule included collection of twenty-four hour flow weighted composite samples of the 

influent and effluent wastewater once per month under normal operating conditions. Stress test periods 

were sampled on a more intense basis with six to eight composite samples being collected during and 

following each stress test period. Five consecutive days of sampling occurred in the twelfth month of the 

verification test. All composite samples were collected using automatic samplers located at the dosing 

channel (influent sample) and at the discharge of the BioclereTM unit. Grab samples were collected on 

each sampling day to monitor the system pH, dissolved oxygen, and temperature. 

All samples were cooled during sample collection, preserved, if appropriate, and transported to the 

laboratory. All analyses were in accordance with EPA approved methods or Standard Methods. An 

established QA/QC program was used to monitor field sampling and laboratory analytical procedures. 

QA/QC requirements included field duplicates, laboratory duplicates and spiked samples, and appropriate 

equipment/instrumentation calibration procedures. Details on all analytical methods and QA/QC 

procedures are provided in the full Verification Report. 

PERFORMANCE VERIFICATION 

Overview 

Evaluation of the AQP BioclereTM Model 16/12 at MASSTC began on January 15, 2001, when the 

BioclereTM pumps and timers were activated, and the initial dosing cycles activated. Flow was set at 400 

gpd, resulting in 15 doses per day with a target of 26.7 gallons per dose. The startup period continued 

until March 13, 2001. Six samples of the influent and effluent were collected during the startup period. 

Verification testing began on March 13, 2001 and continued for 13 months until April 17, 2002. The extra 

month of dosing and sampling (13 months versus the planned 12 months) was added to the test to obtain 

data on the system response as the temperatures began to rise in the spring. During the verification test, 53 

sets of samples of the influent and effluent were collected to determine the system performance. 

Startup 

Overall, the unit started up with no difficulty. The startup instructions in the Technical Manual were easy 

to follow and provided the necessary instructions to get the unit up and operating. No changes were made 

to the unit during the startup period, and no special maintenance was required. Daily observation showed 

that biological growth was established on the media. 

The BioclereTM system performance for CBOD5, TSS, and TN remained relatively steady throughout the 

startup period. Effluent CBOD5 varied between 13 and 51 mg/L, with the lowest value at the end of the 

startup period. There was some indication of TN reduction occurring, with effluent concentrations 

varying between 27 and 36 mg/L compared to influent concentrations of 34 to 46 mg/L. However, it did 

not appear that the nitrifying organisms had established themselves in the system. Low wastewater and 

ambient temperatures were considered the primary reason for the slow trend toward improved reduction 

in both CBOD5 and TN. The temperature of the effluent wastewater was about 5 oC when the unit was 

started and remained in the 5 to 7 o

C range through March 13. 

Verification Test Results 

The daily dosing schedule during normal operations remained constant through the entire verification test. 

A daily dosing sequence of 15 doses was performed every day except during the low load (September 

2001) and vacation stress (Fe bruary 2002) periods. Volume per dose and total daily volume varied only 

slightly during the test period. The daily volume averaged on a monthly basis ranged from 387 to 407 

gallons per day. This compared closely to the 400 gallons per day design capacity. 

The sampling program emphasizes sampling during and following the major stress periods. This results in 

a large number of samples being clustered during five periods, with the remaining samples spread over 

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the remaining months (monthly sampling). Therefore, impacts of a stress test or an upset condition 

occurring during concentrated sampling periods can have an impact on the calculation of average values. 

Both average and median results are presented, as the median values compared to average values can help 

in analyzing these impacts. In the case of the BioclereTM results, the median concentrations are lower than 

the average concentrations due to the upset condition when the nozzles plugged during the working parent 

stress test. 

The TSS and BOD5/CBOD5 results for the verification test, including all stress test periods, are shown in 

Table 1. The influent wastewater had an average BOD5 of 210 mg/L and a median BOD5 of 200 mg/L. 

The TSS in the influent averaged 160 mg/L and had a median concentration of 140 mg/L. The BioclereTM 

effluent showed an average CBOD5 of 14 mg/L with a median CBOD5 of 10 mg/L. The average TSS in 

the effluent was 16 mg/L and the median TSS was 10 mg/L. CBOD5 concentrations in the effluent 

typically ranged from 4 to 20 mg/L, and TSS ranged from 4 to 17 mg/L, except during an apparent upset 

condition that occurred in July 2001. 

Table 1. BOD5/CBOD5 and TSS Data Summary 

BOD5 CBOD5 TSS 

Influent Effluent Percent Influent Effluent Percent 

(mg/L) (mg/L) Removal (mg/L) (mg/L) Removal 

Average 210 14 93 160 16 90 

Median 200 10 95 140 10 93 

Maximum 380 60 98 410 62 98 

Minimum 72 3.5 78 40 2 63 

Std. Dev. 70 11 5.0 71 16 7.0

 Note: The data in Table 1 are based on 53 samples. 

The nitrogen results for the verification test, including all stress test periods, are shown in Table 2. The 

influent wastewater had an average TKN concentration of 37 mg/L, with a median value of 38 mg/L, and 

an average ammonia nitrogen concentration of 23 mg/L, with a median of 23 mg/L. Average TN 

concentration in the influent was 37 mg/L (median of 38 mg/L) based on the assumption that the nitrite 

and nitrate concentrations in the influent were negligible. The BioclereTM effluent had an average TKN 

concentration of 10 mg/L and a median concentration of 6.3 mg/L. The average NH3-N concentration in 

the effluent was 6.2 mg/L and the median value was 2.8 mg/L. The nitrite concentration in the effluent 

was low, averaging 0.45 mg/L. Effluent nitrate concentrations averaged 5.3 mg/L with a median of 4.4 

mg/L. Total nitrogen was determined by adding the concentrations of the TKN (organic plus ammonia 

nitrogen), nitrite and nitrate. Average TN in the BioclereTM effluent was 16 mg/L (median 14 mg/L) for 

the thirteen month verification period. The BioclereTM system averaged a 57 percent reduction of TN for 

the entire test, with a median removal of 64 percent. 

Verification Test Discussion 

Beginning in late March and early April, temperatures began to increase and the nitrifying population 

clearly became established, as indicated by the decrease in the TKN and NH3 concentrations in the 

effluent. Nitrate concentrations increased somewhat in this same period, but the data show that 

denitrification was also occurring. The concentration of organic matter in the effluent, as measured by 

CBOD5 and TSS concentrations, also decreased. During May and June, the TN concentration in the 

effluent was in the range of 8.8 to 11 mg/L. The Washday stress test in May 2001 showed no negative 

impact on nitrogen reduction. 

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Table 2. Nitrogen Data Summary 

TKN Ammonia Total Nitrogen Nitrate Nitrite Temperature 

(mg/L) (mg/L) (mg/L) (mg/L) (mg/L) (°C) 

Influent Effluent Influent Effluent Influent Effluent Effluent Effluent Effluent 

Average 37 10 23 6.2 37 16 5.2 0.45 15 

Median 38 6.3 23 2.8 38 14 4.4 0.34 15 

Maximum 46 35 27 22 46 36 14 1.5 23 

Minimum 24 1.9 18 0.7 24 6.2 <0.1 0.07 7.4 

Std. Dev. 4.4 10 2.1 7.0 4.4 8.4 3.5 0.26 4.9

 Note: The data in Table 2 are based on 53 samples, except for Temperature, which is based on 51 samples. 

In early July 2001, the data show that there was loss of the nitrifying population in the unit, with total 

nitrogen levels in the effluent of 25 to 36 mg/L. The effluent concentrations of CBOD5 and TSS also 

increased during this time, indicating the system was under stress. It was discovered that two of the 

nozzles in the BioclereTM unit were clogged. AQP responded to the problem and cleaned the nozzles, and 

within two to three weeks, the TN concentration decreased to 9.4 mg/L, similar to the period before the 

problem occurred. The CBOD5 and TSS levels in the effluent also decreased, returning to the levels 

measured before the nozzle plugging occurred. The loss of nitrogen and CBOD5 removal efficiency 

during the nozzle -plugging problem makes it unclear whether the Working Parent dose sequence would 

have had an impact on the system. 

Once the nitrifying population was reestablished, the BioclereTM system continued to reduce the total 

nitrogen concentration on a consistent basis (7.7 to 11 mg/L) until December. This period included the 

Low Dose sequence, when the BioclereTM was dosed with 50 percent of the daily design loading, which 

appears to have had no impact on the system operation. The temperature of the wastewater began to 

decrease in October, as would be expected. While the trend was not clear, the late November sample 

indicated a lower removal of nitrogen was occurring as compared to September and October. The Power 

Failure stress test (power shut off for 48 hours) was started on December 3, 2001. Sample results for the 

post stress period showed effluent total nitrogen had increased to 18 mg/L, while subsequent monitoring 

over the next few weeks showed the total nitrogen concentration to be in the range of 6.2 to 19 mg/L. 

Most of the concentrations were in the 13 to 19 mg/L range, with influent levels of 35 to 46 mg/L. The 

lower nitrogen removal efficiencies in the December to February period correspond to lower temperatures 

in the wastewater. It appears that the Power Failure stress test may have contributed to the change in 

efficiency by stressing the nitrifying population. The lower temperatures in the wastewater appeared to 

have slowed the total nitrogen removal and possibly the re-establishment of the nitrifying population. 

The Vacation stress test in February had no noticeable impact on the system performance for nitrogen 

removal. The last scheduled samples for total nitrogen in the first week of March showed that the 

BioclereTM system was removing TN in the 60 to 66 percent range, somewhat lower than the efficiencies 

of the previous summer and fall. The temperature of the wastewater appeared to have an effect on the 

nitrogen reduction levels based on both the startup data and on the December 2001 to February 2002. The 

test period was extended one additional month to determine if removal would improve as the wastewater 

temperature increased. The final sample showed a sharp decrease in TN from 16 mg/L on March 8 to 8 

mg/L on April 17. During this period, the temperature of the wastewater increased to 14.3 o

C from 9.2 oC. 

Operation and Maintenance Results 

Noise levels associated with mechanical equipment were measured once durin g the verification period 

using a decibel meter. Measurements were made one meter from the unit, and one and a half meters above 

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the ground, at 90� intervals in four (4) directions. The average decibel level was 49.5, with a minimum of 

45.5 and maximum of 52.8. The background level was 37.7 decibels. 

Odor observations were made monthly for the last eight months of the verification test. The observations 

were qualitative based on odor strength (intensity) and type (attribute). Observations were made during 

periods of low wind velocity (<10 knots), at a distance of three feet from the treatment unit, and recorded 

at 90� intervals in four directions. There were no discernible odors found during any of the observation 

periods. 

Electrical use was monitored by a dedicated electric meter serving the BioclereTM system. The average 

electricity use was 4.2 kW/day. The BioclereTM system does not require or use any chemical addition as 

part of the normal operation of the unit. 

During the test, very few problems were encountered with the operation of the system with the exception 

of the plugged nozzles after five and half months of operation. The plugging problem was discovered 

when the effluent’s visual characteristic changed and had notably more suspended solids. In addition, 

during the nozzle plugging, the noise level of the spray hitting the inside of the media containment 

structure was slightly louder, signaling higher flow through one of the nozzles and overloading of a 

portion of the media bed. The nozzles were cleaned again in the fall by AQP in accordance with the 

quarterly maintenance check recommended in their O&M manual. AQP installed a new set of helical 

nozzles in January 2002. These nozzles required no additional cleaning through the remainder of the test. 

AQP believes that the nozzle plugging problem was a unique occurrence as this type of unit had been 

operated at MASSTC and many other locations without a problem. AQP added a statement regarding the 

nozzle issue at the end of the Verification Report. 

Routine quarterly maintenance by a person knowledgeable of the treatment system was recommended in 

the O&M manual, and was confirmed to be appropriate by the BCDHE staff during the test. The 

maintenance should involve checking the two pumps (recirculating and recycling), the fan, and cleaning 

the distribution manifold and nozzles. The maintenance check should also include measurement of the 

sludge depth in the primary tank, observation of the condition of the media, and a visual inspection of the 

effluent. Pump cycle times should be verified and alarms checked. 

The treatment unit itself proved durable for the duration of the test and appears to generally be a durable 

fiberglass design. The piping is standard PVC that is appropriate for the applications. Pump and level 

switch life are always difficult to estimate, but the components used are made for wastewater applications 

by a reputable and known manufacturer. 

Quality Assurance/Quality Control 

QA audits of the MASSTC and BCDHE laboratory were completed by NSF International during testing. 

NSF personnel completed a technical systems audit to assure the testing was in compliance with the test 

plan, a performance evaluation audit to assure that the measurement systems employed by MASSTC and 

the BCDHE laboratory were adequate to produce reliable data, and a data quality audit of at least 10 

percent of the test data to assure that the reported data represented the data generated during the testing. In 

addition to quality assurance audits performed by NSF International, EPA QA personnel conducted a 

quality systems audit of NSF International's QA Management Program, and accompanied NSF during 

audits of the MASSTC and BCDHE facilities. 

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Original signed by 

Hugh W. McKinnon 5/30/03 

Hugh W. McKinnon Date 

Director 

National Risk Management Research Laboratory 

Office of Research and Development 

United States Environmental Protection Agency 

Original signed by 

Gordon E. Bellen 6/3/03 

Gordon E. Bellen 

Vice President 

Research 

NSF International 

Date 

NOTICE: Verifications are based on an evaluation of technology performance under specific, 

predetermined criteria and the appropriate quality assurance procedures. EPA and NSF make no 

expressed or implied warranties as to the performance of the technology and do not certify that a 

technology will always operate as verified. The end user is solely responsible for complying with 

any and all applicable federal, state, and local requirements. Mention of corporate names, trade 

names, or commercial products does not constitute endorsement or recommendation for use of 

specific products. This report in no way constitutes an NSF Certification of the specific product 

mentioned herein. 

Availability of Supporting Documents 

Copies of the ETV Protocol for Verification of Residential Wastewater Treatment 

Technologies for Nutrient Reduction, dated November 2000, the Verification Statement, 

and the Verification Report are available from the following sources: 

1. ETV Water Quality Protection 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) 

(NOTE: Appendices are not included in the Verification Report. Appendices are 

available from NSF upon request.) 

EPA’s Office of Wastewater Management has published a number of documents to assist 

purchasers, community planners and regulators in the proper selection, operation and 

management of onsite wastewater treatment systems. Two relevant documents and their 

sources are: 

1. Handbook for Management of Onsite and Clustered Decentralized Wastewater 

Treatment Systems http://www.epa.gov/owm/onsite 

2. Onsite Wastewater Treatment Systems Manual 

http://www.epa/gov/owm/mtb/decent/toolbox.htm 

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