April 2003
NSF 02/03AVQPC-SWP
Environmental Technology
Verification Report
Reduction of Nitrogen in Domestic
Wastewater from Individual
Residential Homes
Waterloo Biofilter Systems, Inc.
Waterloo Biofilter® Model 4 Bedroom
Prepared by
NSF International
Under a Cooperative Agreement with
A ERA U.S. Environmental Protection Agency
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THE ENVIRONMENTAL TECHNOLOGY VERIFICATION
PROGRAM
&EPA
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:
WATERLOO BIOFILTER® MODEL 4-BEDROOM
COMPANY:
WATERLOO BIOFILTER SYSTEMS, INC.
ADDRESS:
143 DENNIS ST., P.O. BOX 400 PHONE: (519)856-0757
ROCKWOOD, ONTARIO, NOB 2K0
CANADA FAX: (519) 856-0759
WEB SITE:
EMAIL:
http: // www. waterloo-biofilter. com
infoSjwaterloo-biofilter. com
NSF International (NSF) operates the Water Quality Protection Center (WQPC) under the U.S. Environmental
Protection Agency's Environmental Technology Verification (ETV) Program. The WQPC evaluated the
performance of a fixed film trickling filter biological treatment system for nitrogen removal for residential
applications. This verification statement provides a summary of the test results for the Waterloo Biofilter
Systems, Inc. Waterloo Biofilter® Model 4-Bedroom system. The Barnstable County (Massachusetts)
Department of Health and the Environment (BCDHE) performed the verification testing.
The U.S. Environmental Protection Agency (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 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.
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ABSTRACT
Verification testing of the Waterloo Biofilter Systems (WBS), Inc. Waterloo Biofilter® Model 4Bedroom
system 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 Waterloo® 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 Waterloo® system proved capable of
removing nitrogen from the wastewater. The influent total nitrogen (TN), as measured by TKN, averaged 37
mg/L with a median of 37 mg/L. The effluent TN (TKN plus nitrite/nitrate) concentration averaged 14 mg/L
over the verification period, with a median concentration of 13 mg/L, which included an average TKN
concentration of 3.7 mg/L and a median concentration of 1.6 mg/L. The system operating conditions (on-
demand pump and float settings) remained constant during the test. Routine maintenance and system checks
were performed for most of the test, except when media (foam cubes) was added after four months of operation.
Adding media may be part of on-going maintenance, especially in the first few months according to the WBS
Design, Installation, and Service Manual.
TECHNOLOGY DESCRIPTION
The Waterloo Biofilter® Model 4-Bedroom system is a two stage treatment technology, based on a fixed film
trickling filter, using patented foam cubes to achieve treatment. The first stage of treatment occurs in the
primary tank (normally a 1,500 gallon two compartment septic tank, a single compartment tank was used for the
test) in which the solids are settled and partially digested. The second stage, the Biofilter® unit, is a separate
system that provides secondary wastewater treatment. Microorganisms present in the wastewater attach to the
Waterloo® patented foam media, and use the nutrients and organic materials provided by the constant supply of
fresh wastewater to form new cell mass. The system does not have a fan, as passive aeration to support the
microorganisms is provided by openings in the Biofilter® housing and the characteristics of the foam material,
allowing air to freely pass through the media.
The Waterloo Biofilter® system is designed to remove total nitrogen from the wastewater by nitrification and
denitrification. Nitrification occurs in the aerobic Biofilter® unit, where ammonia nitrogen is converted to nitrite
and nitrate (predominately nitrate), while denitrification occurs in the anaerobic/anoxic primary tank, where the
nitrite/nitrate is converted to nitrogen gas.
The verification testing was performed using a full scale, commercially available unit, which was received as a
self-contained system ready for installation. Primary tank effluent flowed by gravity through an effluent screen
(Zabel filter) to the pump/collection chamber. A pump in the chamber transferred the primary tank effluent to
the Biofilter® spray nozzles located above the foam media, which was contained in baskets. The pump operated
as an on-demand system, with a level control switch turning the pump on whenever the pump chamber
accumulated six gallons of wastewater. The system had a gravity recycle line that recirculated approximately 50
percent of the treated effluent and any solids (if present) from the underflow of the Biofilter® back to the
primary tank. The spray system and media were housed in an above grade, lined wooden enclosure.
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 in testing. A chamber located in the main
interceptor sewer to the base wastewater treatment facility provides a location to obtain untreated wastewater.
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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 that 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 Biofilter® was installed by a contractor, in
conjunction with the BCDHE support team, in May 1999 as part of an earlier test program. The unit was
installed in accordance with the Design, Installation, and Service Manual supplied by WBS. In order to prepare
for ETV testing, the entire Waterloo® system was emptied of wastewater and cleaned. Solids were removed
from the primary tank, and all pumps, lines, and associated equipment were cleaned. The foam filter media was
replaced with new media.
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 WBS Design, Installation, and Service
Manual, allowed the biological community to become established and allowed the operating conditions to be
monitored. Startup of the cleaned Biofilter® system began on January 15, 2001, when the primary tank was filled
with wastewater from the dosing channel. The dosing sequence was then started, with the unit's pump and level
switches set in accordance with the WBS Manual.
The system was monitored during the startup period, including 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. Effluent samples
were analyzed for pH, alkalinity, temperature, CBOD5, TKN, NH3, TSS, dissolved oxygen, N02, and N03.
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 two-month
intervals, and included Washday, Working Parent, Low Load, Power/Equipment Failure, and Vacation test
sequences. Monitoring for nitrogen reduction was accomplished by measurement of nitrogen species (TKN,
NH3, NO2, N03). Biochemical oxygen demand (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 Biofilter® system has a design capacity of 440 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 Biofilter® system was dosed 15 times per day with approximately 29-30 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.
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 Biofilter® unit. Grab samples were collected on each sampling day to monitor the system pH,
dissolved oxygen, and temperature.
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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 Waterloo Biofilter® Model 4-Bedroom system at MASSTC began on January 15, 2001, when
the Biofilter® pump was activated, and the initial dosing cycles activated. Flow was set at 440 gpd, resulting in
15 doses per day with a target of 29.33 gallons per dose. Six samples of the influent and effluent were collected
during the startup period, which continued until March 13, 2001. Verification testing began at that time 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 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. Regular observation showed that biological growth
was established on the media during the startup period.
The Biofilter® system performance for CBOD5, TSS, and TN appeared good during the first three weeks of
operation, but did not continue to improve over the next five weeks. Effluent CBOD5 varied between 23 and 66
mg/L, with the higher value at the end of the startup period. There was some initial indication that TN removal
was occurring, with effluent concentrations of 18 to 31 mg/L during the first three weeks, compared with
influent concentrations of 34 to 41 mg/L. However, after eight weeks it did not appear that the nitrifying
organisms had established themselves in the system, with low wastewater and ambient temperatures considered
the primary reasons for the slow trend toward improved reduction in both CBOD5 and TN. The temperature of
the effluent wastewater was about 4 °C when the unit was started and remained in the 5 to 8 °C range through
March 13. After startup, and early in the verification test in late April, it was discovered that the foam media had
settled and short-circuiting was occurring in both media baskets. Foam media was added to the unit (a simple
process) in accordance with the WBS instructions. The WBS maintenance recommendations and checklist
include a regular check of the foam media and the addition of media, if needed.
Verification Test Results
The daily dosing schedule was designed for 15 doses to be applied every day, except during the Low Load
(September 2001) and Vacation stress (February 2002) periods. In September, it was discovered that only 14
doses were being delivered because of a timing issue with the PLC. The issue was resolved and 15 doses were
delivered for the last eight months of the test. Volume per dose and total daily volume varied only slightly
during the test period. The daily volume, averaged on a monthly basis, ranged from 401 to 444 gallons per day.
This was within the range allowed in the protocol for the 440 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 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
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impacts. In the case of the Biofilter® results, the median concentrations are somewhat lower than the average
concentrations due to an upset condition following the Vacation 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 150 mg/L and had a median concentration of 130 mg/L. The Biofilter® effluent showed an
average CBOD5 of 10 mg/L with a median CBOD5 of 7.4 mg/L. The average TSS in the effluent was 7 mg/L
and the median TSS was 5 mg/L. CBOD5 concentrations in the effluent typically ranged from 1 to 10 mg/L, and
TSS ranged from 1 to 20 mg/L.
Table 1. BOD5/CBOD5 and TSS Data Summary
bod5
CBODs
TSS
Influent
Effluent
Percent
Influent
Effluent
Percent
(mg/L)
(mg/L)
Removal
(mg/L)
(mg/L)
Removal
Average
210
10
95
150
7
95
Median
200
7.4
96
130
5
97
Maximum
370
43
99
340
55
>99
Minimum
67
1.0
71
61
<1
51
Std. Dev.
73
9.0
6.0
66
8
8
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 37 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 37 mg/L), based on the assumption that the nitrite and nitrate concentrations in
the influent were negligible. The Biofilter® effluent had an average TKN concentration of 3.7 mg/L and a
median concentration of 1.6 mg/L. The average NH3-N concentration in the effluent was 2.4 mg/L and the
median value was 0.7 mg/L. The nitrite concentration in the effluent was low, averaging 0.19 mg/L. Effluent
nitrate concentrations averaged 10 mg/L with a median of 10 mg/L. Total nitrogen was determined by adding
the daily concentrations of the TKN (organic plus ammonia nitrogen), nitrite, and nitrate. Average TN in the
Biofilter® effluent was 14 mg/L (median 13 mg/L) for the thirteen month verification period. The Biofilter®
system averaged a 62 percent reduction of TN for the entire test, with a median removal of 65 percent.
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
Influent
Average
37
3.7
23
2.4
37 14
10
0.19
15
Median
37
1.6
23
0.7
37 13
10
0.14
15
Maximum
45
31
29
24
45 45
33
0.84
24
Minimum
24
<0.5
18
<0.2
24 6.8
0.6
<0.05
5.2
Std. Dev.
4.1
5.5
2.4
4.0
4.2 6.0
5.0
0.20
5.9
NOTE: The data in Table 2 are based on 53 samples, except for Temperature, which is based on 51 samples.
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Verification Test Discussion
In late March and early April 2001, when temperatures began to increase, there was evidence of a more
established biological population on the foam media. In late April, when it was discovered that the foam
media had settled and wastewater was short-circuiting through the media, media was added to the unit. With the
increasing temperatures and the elimination of the short-circuiting, the nitrifying population clearly became
established, as indicated by the decrease in the TKN and ammonia concentrations in the effluent, and an
increase in effluent nitrate concentration. TN concentration in the effluent began to decrease indicating that the
denitrification population was becoming established in the primary tank. During May and June, the TN
reduction was typically in 65 to 80 percent range. The Washday stress test performed in May 2001 did not
appear to have a negative impact on nitrogen reduction. Likewise, in July 2001, the Working Parent stress test
was performed and the performance of the unit remained steady during and following the stress period. The
Biofilter® system continued to reduce the total nitrogen concentration on a steady basis (60-80 percent
reduction) until February 2002. During this period, which included the Low Load and Power/Equipment Failure
stress sequences, nitrification was very effective, with ammonia nitrogen and TKN being reduced to less than 1
mg/L. The denitrification process during this period was effective in removing nitrate produced during the
nitrification step, but not as efficient or complete as the nitrifying step. The total nitrogen in the effluent ranged
from 6.2 to 13 mg/L during the August to January period.
The Vacation stress test was started on February 4 and was completed on February 13, 2002. The sample taken
before the stress test showed some signs that the denitrification process was slowing, while the nitrification
process, as measured ty TKN (1.6 mg/L) and ammonia (1.5 mg/L), was still consistent. Effluent CBOD5 and
TSS concentrations continued to be low, with values of 4.4 and 8 mg/L, respectively. On the first day after the
Vacation stress test ended, the effluent nitrate value jumped to 33 mg/L, the ammonia level increased to 10
mg/L, total nitrogen went to 45 mg/L, and CBOD5 and TSS increased. It would appear that both the nitrification
and denitrification processes were impacted during this time by the lack of wastewater application to the media
(no flow for eight days). The use of the "on-demand" pumping approach results in no application of wastewater
to support the biological population on the Biofilter® when there is no flow to the system. The timing of the
Vacation stress test dso coincided with the coldest time of the year, with the temperature of the effluent
dropping to 5 °C from 7 °C on first day after the stress period ended.
Performance began to improve almost immediately after the flow returned to normal conditions. In general, the
effluent nitrogen concentrations were nearly back to pre-stress levels within one to two weeks of the resumption
of dosing. Likewise, CBOD5 and TSS concentrations returned to levels close to those prior to the stress. The
overall performance of the system was slightly lower during the weeks following the Vacation stress test, as
compared to the October to December 2001 period, showing effluent TN concentrations of 15 to 17 mg/L versus
9 to 11 mg/L.
The last sample collected in April 2002 indicated that the both the nitrifying and denitrifying processes had
recovered, and the TN concentration in the effluent was 11 mg/L. TKN and ammonia concentrations were 3.5
mg/L and 1.1 mg/L, respectively, only slightly higher than the less than 1 mg/L levels achieved in previous
summer and fall periods. The nitrate concentration was 7.1 mg/L, which was actually on the low side of the
levels found in the summer and fall. The verification test provided a sufficiently long test period to collect data
that included both a long run of steady performance by the Biofilter® system and a period of an apparent upset
following the Vacation stress test. While the system was apparently impacted by the Vacation stress test and
probably by the low temperatures, recovery was rapid with TN removal on the order of 60 percent (55-70
percent measured) being established within two to four weeks.
Operation and Maintenance Results
Noise levels associated with mechanical equipment were measured once during the verification period using a
decibel meter. Measurements were made one meter from the unit, and one and a half meters above the ground,
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at 90° intervals in four (4) directions. The average decibel level was 47.6, with a minimum of 44.8 and
maximum of 50.5. 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 during any of the observation periods. The unit has two
charcoal filters to help control odors. No maintenance was required on these units during the test.
Electrical use was monitored by a dedicated electric meter serving the Biofilter® system. The average electrical
use was 1.3 kW/day with a maximum of 2.5 kW/day. The Biofilter® system does not require or use any
chemical addition as part of the normal operation of the unit.
During the test, no problems were encountered with the operation of the system. The screen on the outlet from
the septic tank (influent to the pump chamber) required periodic cleaning. During the test, the filter was cleaned
after eight months (two months of startup and six months of testing) in accordance with the WBS
recommendation. The distribution plates near the nozzles were cleaned when the outlet screen was cleaned to
help maintain a uniform spray pattern over the media. No changes or adjustments were needed to the float
switches or the pump. Media was added one time after four months of operation. No additional media was added
for the duration of the test.
The treatment unit itself proved durable for the duration of the test and appears to generally be a durable design.
The piping is standard PVC that is appropriate for the applications. Pump and level switch life is always difficult
to estimate, but the equipment used is made for wastewater applications by a reputable and known manufacturer.
The lined wooden box used as housing did attract ants that bore through the wood. This was solved by liberal
application of borax in the area of the unit.
WBS recommends a minimum of once per year maintenance checks, and the sample maintenance contract is
designed for twice per year maintenance of the unit. Based on fifteen months of observation, BCHDE staff
believes that quarterly maintenance checks would seem appropriate to ensure the system is in good operating
condition. It is possible that a knowledgeable homeowner could perform certain routine quarterly checks, after
the system has been in operation for several months, and routinely checked by a trained operator. Homeowner
involvement in routine cleaning and system checks might be able to reduce the scheduled contractor
maintenance to a semi-annual frequency. Maintenance activities should include checking the filter media for
subsidence, adding media if needed, checking the nozzles and distribution plates for clogging and cleaning if
needed, and checking the pump, alarms, and floats for proper operation. The primary tank should be checked for
sludge depth and the primary tank effluent screen should be cleaned. Replacement of the activated carbon
located on the air openings should be part of routine maintenance, but the carbon life may be long, and
replacement only needed if odor becomes a problem.
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
Original signed by
Gordon E. Be lien 6/3/03
Hugh W. McKinnon Date
Director
National Risk Management Research Laboratory
Office of Research and Development
United States Environmental Protection Agency
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 ofResidential 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. Handbookfor 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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Environmental Technology Verification Report
Nutrient Reduction in Domestic Wastewater
From Individual Residential Homes
Waterloo Biofilter Systems, Inc.
Waterloo Biofilter® Model 4-Bedroom
Prepared for
NSF International
Ann Arbor, MI 48105
Prepared by
Scherger Associates
In cooperation with
Barnstable County Department of Health and Environment
Under a cooperative agreement with the U.S. Environmental Protection Agency
Raymond Frederick, Project Officer
ETV Water Quality Protection Center
National Risk Management Research Laboratory
Water Supply and Water Resources Division
U.S. Environmental Protection Agency
Edison, New Jersey 08837
April 2003
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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 a
Cooperative Agreement. The Water Quality Protection Center, Source Water Protection area,
operating under the Environmental Technology Verification (ETV) Program, supported this
verification effort. This document has been peer reviewed and reviewed by NSF and EPA and
recommended for public release.
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Foreword
The following is ihe final report on an Environmental Technology Verification (ETV) test
performed for NSF International (NSF) and the United States Environmental Protection Agency
(EPA) by the Barnstable County Department of Health and Environment (BCDHE). Scherger
Associates prepared the Verification Report in cooperation with BCDHE. The verification test
for Waterloo Biofilter® System was conducted from January 2001 through April 2002 at the
Massachusetts Alternative Septic System Test Center (MASSTC) test site in Bourne,
Massachusetts.
Throughout its history, the EPA has evaluated the effectiveness of innovative technologies to
protect human health and the environment. A new EPA program, the Environmental
Technology Verification Program was developed to verify the performance of innovative
technical solutions to environmental pollution or human health threats. ETV was created to
substantially accelerate the entrance of new environmental technologies into the domestic and
international marketplace. Verifiable, high quality data on the performance of new technologies
are made available to end users regulators, developers, consulting engineers, and those in the
public health and environmental protection industries. This encourages rapid availability of
approaches to better protect the environment.
The EPA has partnered with NSF, to verify performance of various treatment systems designed
to remove pollutants and protect water used as a source for drinking water and other uses under
the Source Water Protection (SWP) area of the Water Quality Protection Center (WQPC). NSF
is an independent, not-for-profit testing and certification organization dedicated to public health,
safety and protection of the environment. A goal of verification testing is to enhance and
facilitate the acceptance of small treatment systems and equipment by state 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 Testing Organizations (TO) to conduct verification testing under the approved
protocols. The Barnstable County Department of Health and Environment is one such TO.
NSF is conducting the WQPC-SWP with participation of manufacturers, under the sponsorship
of the EPA Office of Research and Development, National Risk Management Research
Laboratory, Urban Watershed Management Branch, Edison, New Jersey. It is important to note
that verification of the equipment does not mean that 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 TO.
111
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Table of Contents
Verification Statement VS-i
Notice ii
Foreword iii
Table of Contents iv
List of Appendices v
List of Tables vi
List of Figures vi
Glossary of Terms vii
Abbreviations and Acronyms ix
Acknowledgments x
1.0 Introducti on 1-1
1.1 ETV Purpose and Program Operation 1-1
1.2 Testing Participants and Responsibilities 1-1
1.2.1 NSF International - Verification Organization (VO) 1-2
1.2.2 U.S. Environmental Protection Agency 1-3
1.2.3 Testing Organization 1-3
1.2.4 Technology Vendor 1-5
1.2.5 ETV Test Site 1-6
1.2.6 Technology Panel 1-6
1.3 Background - Nutrient Reduction 1-7
1.3.1 Fixed Film Trickling Filter - Biological Nitrification 1-7
1.3.2 Biological Denitrification 1-9
2.0 Technology Description and Operating Processes 2-1
2.1 Technology Description 2-1
2.2 Waterloo Biofilter® Equipment and Process Description 2-1
2.3 Equipment Specifications 2-5
2.4 Operation and Maintenance 2-5
2.5 Vendor Claims 2-6
3.0 Methods and Test Procedures 3-1
3.1 Verification Test Plan and Procedures 3-1
3.2 MASSTC Test Site Description 3-1
3.3 Installation and Startup Procedures 3-3
3.3.1 Introduction 3-3
3.3.2 Objectives 3-3
3.3.3 Installation and Startup Procedures 3-3
3.4 Verification Testing - Procedures 3-4
3.4.1 Introduction 3-4
3.4.2 Objectives 3-4
3.4.3 System Operation- Flow Patterns and Loading Rates 3-4
3.4.3.1 Influent Flow Pattern 3-5
3.4.3.2 Stress Testing Procedures 3-5
3.4.3.3 Sampling Locations, Approach, and Frequency 3-7
3.4.3.4 Residuals Monitoring and Sampling 3-10
3.4.4 Analytical Testing and Record Keeping 3-11
iv
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3.4.5 Operation and Maintenance Performance 3-12
3.4.5.1 Electric Use 3-12
3.4.5.2 Chemical Use 3-12
3.4.5.3 Noise 3-12
3.4.5.4 Odors 3-13
3.4.5.5 Mechanical Components 3-13
3.4.5.6 Electrical/Instrumentation Components 3-13
4.0 Results and Discussion 4-1
4.1 Introduction 4-1
4.2 Startup Test Period 4-1
4.2.1 Startup Flow Conditions 4-1
4.2.2 Startup Analytical Results 4-2
4.2.3 Startup Operating Conditions 4-3
4.3 Verification Test 4-3
4.3.1 Verification Test - Flow Conditions 4-4
4.3.2 BOD5/CBOD5 and Suspended Solids Results 4-5
4.3.3 Nitrogen Reduction Performance 4-12
4.3.3.1 Results 4-12
4.3.3.2 Discussion 4-13
4.3.4 Residuals Results 4-24
4.4 Operations and Maintenance 4-25
4.4.1 Electric Use 4-25
4.4.2 Chemical Use 4-26
4.4.3 Noise 4-26
4.4.4 Odor Observations 4-27
4.4.5 Operation and Maintenance Observations 4-27
4.5 Quality Assurance/ Quality Control 4-30
4.5.1 Audits 4-30
4.5.2 Daily Flows 4-31
4.5.3 Precision 4-31
4.5.4 Accuracy 4-35
4.5.5 Representativeness 4-37
4.5.6 Completeness 4-37
5.0 REFERENCES 5-1
5.1 Cited References 5-1
5.2 Additional Background References 5-1
List of Appendices
Appendix A - Design, Installation, and Service Manual
Appendix B - Verification Test Plan
Appendix C - MASSTC Field SOP's
Appendix D - Lab Data and QA/QC Data
Appendix E - Field Lab Log Book
Appendix F - Spreadsheets with calculation and data summary
Appendix G - Field Operations Logs
v
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List of Tables
Table 2-1. Waterloo Biofilter® Specifications 2-5
Table 3-1. Historical MASSTC Wastewater Data 3-2
Table 3-2. Sampling Matrix 3-8
Table 3-3. Sampling Schedule for Waterloo Biofilter® System 3-10
Table 3-4. Summary of Analytical Methods and Precision and Accuracy Requirements 3-11
Table 4-1. Flow - Volume Data during the Startup Period 4-2
Table 4-2. Influent Wastewater Quality - Startup Period 4-3
Table 4-3. Waterloo Biofilter® Effluent Quality - Startup Period 4-3
Table 4-4. Waterloo Biofilter® Influent Volume Summary 4-5
Table 4-5. Waterloo Biofilter® BOD5/CBOD5 and TSS Results 4-10
Table 4-6. Waterloo Biofilter® Influent and Effluent Nitrogen Data 4-20
Table 4-7. Waterloo Biofilter® Alkalinity, pH, and Dissolved Oxygen Results 4-22
Table 4-8. Solids/Scum Depth Measurement 4-24
Table 4-9. TSS and VSS Results for the Waterloo Biofilter® Solids Sample 4-25
Table 4-10. Summary of Waterloo Biofilter® Electrical Usage 4-26
Table 4-11. Waterloo Biofilter® Noise Measurements 4-26
Table 4-12. Odor Observations 4-27
Table 4-13. Duplicate Field Sample Summary - Nitrogen Compounds 4-32
Table 4-14. Duplicate Field Sample Summary- CBOD, BOD, Alkalinity, TSS 4-33
Table 4-15. Duplicate Field Sample Summary - pH, Dissolved Oxygen 4-33
Table 4-16. Laboratory Precision Data - Nitrogen Compounds 4-34
Table 4-17. Laboratory Precision Data - CBOD5, BOD5, Alkalinity, TSS 4-35
Table 4-18. Accuracy Results - Nitrogen Analyses 4-36
Table 4-19. Accuracy Results - CBOD, BOD, Alkalinity 4-36
List of Figures
Figure 2-1. Waterloo Biofilter® Schematic Representation 2-3
Figure 2-2. Waterloo Biofilter® System Pump Chamber 2-4
Figure 2-3. Waterloo Biofilter® Filter Schematic 2-4
Figure 4-1. Waterloo Biofilter® BOD5/CBOD5 Results 4-8
Figure 4-2. Waterloo Biofilter® Total Suspended Solids Results 4-9
Figure 4-3. Waterloo Biofilter® Total Kjeldahl Nitrogen Results 4-15
Figure 4-4. Waterloo Biofilter® Ammonia Nitrogen Results 4-16
Figure 4-5. Waterloo Biofilter® Total Nitrogen Results 4-17
Figure 4-6. Waterloo Biofilter® Nitrite and Nitrate Effluent Concentrations 4-18
Figure 4-7. Waterloo Biofilter® Effluent Temperature 4-19
vi
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Glossary of Terms
Accuracy - a measure of the closeness of an individual measurement or the average of a number
of measurements to the true value and includes random error and systematic error.
Bias - the systematic or persistent distortion of a measurement process that causes errors in one
direction.
Commissioning - the installation of the nutrient reduction technology and start-up of the
technology using test site wastewater.
Comparability - a qualitative term that expresses confidence that two data sets can contribute to
a common analysis and interpolation.
Completeness - a qualitative and quantitative term that expresses confidence that all necessary
data have been included.
Precision - a measure of the agreement between replicate measurements of the same property
made under similar conditions.
Protocol - a written document that clearly states the objectives, goals, scope and procedures for
the study. A protocol shall be used for reference during Vendor participation in the verification
testing program.
Quality Assurance Project Plan - a written document that describes the implementation of
quality assurance and quality control activities during the life cycle of the project.
Residuals - the waste streams, excluding final effluent, which are retained by or discharged
from the technology.
Representativeness - a measure of the degree to which data accurately and precisely represent a
characteristic of a population parameter at a sampling point, a process condition, or
environmental condition.
Standard Operating Procedure - a written document containing specific procedures and
protocols to ensure that quality assurance requirements are maintained.
Technology Panel - a group of individuals established by the Verification Organization with
expertise and knowledge in nutrient removal technologies.
Testing Organization - an independent organization qualified by the Verification Organization
to conduct studies and testing of nutrient removal technologies in accordance with protocols and
test plans.
Vendor - a business that assembles or sells nutrient reduction equipment.
vii
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Verification - to establish evidence on the performance of nutrient reduction technologies under
specific conditions, following a predetermined study protocol(s) and test plan(s).
Verification Organization - an organization qualified by EPA to verify environmental
technologies and to issue Verification Statements and Verification Reports.
Verification Report - a written document containing all raw and analyzed data, all QA/QC data
sheets, descriptions of all collected data, a detailed description of all procedures and methods
used in the verification testing, and all QA/QC results. The Verification Test Plan(s) shall be
included as part of this document.
Verification Statement - a document that summarizes the Verification Report and is reviewed
and approved by EPA.
Verification Test Plan - A written document prepared to describe the procedures for conducting
a test or study according to the verification protocol requirements for the application of nutrient
reduction technology at a particular test site. At a minimum, the Verification Test Plan includes
detailed instructions for sample and data collection, sample handling and preservation, and
quality assurance and quality control requirements relevant to the particular test site.
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Abbreviations and Acronyms
ANSI
American National Standards Institute
BDCHE
Barnstable County Department of Health and the Environment
Biofilter®
Waterloo Biofilter® Model 4-Bedroom
BOD5
Biochemical Oxygen Demand (five day)
CBOD5
Carbonaceous Biochemical Oxygen Demand (five day)
coc
Chain of Custody
DO
Dissolved Oxygen
DQI
data quality indicators
DQO
data quality objectives
ETV
Environmental Technology Verification
GAI
Groundwater Analytical, Inc.
gal
gallons
gpm
gallons per minute
MASSTC
Massachusetts Alternative Septic System Test Center
mg/L
milligrams per liter
mL
milliliters
NIST
National Institute of Standards and Technology
NH3/NH4
Ammonia Nitrogen
N02
Nitrite Nitrogen
N03
Nitrate Nitrogen
NSF
NSF International
NRMRL
National Risk Management Research Laboratory
O&M
Operation and maintenance
ORD
Office of Research and Development, EPA
OSHA
Occupational Safety and Health Administration
QA
Quality assurance
QAPP
Quality assurance project plan
QC
Quality control
QMP
Quality management plan
RPD
Relative percent difference
SAG
Stakeholders Advisory Group
SOP
Standard operating procedure
SWP
Source Water Protection Area, Water Quality Protection Center
TKN
Total Kjeldahl Nitrogen
TN
Total Nitrogen
TO
Testing Organization
EPA
United States Environmental Protection Agency
VO
Verification Organization
VR
Verification Report
VTP
Verification Test Plan
WBS
Waterloo Biofilter Systems, Inc.
WQPC
Water Quality Protection Center
IX
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Acknowledgments
The Testing Organization (TO), the Barnstable County Department of Health and the
Environment, was responsible for all elements in the testing sequence, including collection of
samples, calibration and verification of instruments, data collection and analysis, and data
management. Mr. George Heufelder was the Project Manager for the Verification Test.
Barnstable County Department of Health and the Environment
Superior Court House (P.O. Box 427)
Barnstable, MA 02630
(508)375-6616
Contact: Mr. George Heufelder, Project Manager
Email: gheufeld@capecod.net
The Verification Report was prepared by Scherger Associates.
Scherger Associates
3017 Rumsey Drive
Ann Arbor, MI 48105
(734)213-8150
Contact: Mr. Dale A. Scherger
Email: Daleres@aol.com
The laboratories that conducted the analytical work for this study were:
Barnstable County Department of Health and the Environment Laboratory
Superior Court House (P.O. Box 427)
Barnstable, MA 02630
(508) 375-6606
Contact: Dr. Thomas Bourne
Email: bcdhelab@cape.com
Groundwater Analytical, Inc. (GWI)
228 Main St.
Buzzards Bay, MA 02532
(508)759-4441
Contact: Mr. Eric Jensen
The Manufacturer of the Equipment was:
Waterloo Biofilter Systems, Inc.
143 Dennis Street, P.O. Box 400
Rockwood, Ontario, NOB 2K0 Canada
(519)856-0757
Contact: Dr. E. Craig Jowett, Ph.D., P.Eng.
Email: craig@waterloo-bi ofilter. com
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The TO wishes to thank NSF International, especially Mr. Thomas Stevens, Project Manager,
and Ms. Maren Roush, Project Coordinator, for providing guidance and program management.
XI
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1.0 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 substantially accelerating
the acceptance and use of innovative, 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; stakeholders
groups which consist of buyers, vendor organizations, consulting engineers, and regulators; 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 (as appropriate) testing, collecting and analyzing
data, and preparing peer reviewed reports. All evaluations are conducted in accordance with
rigorous quality assurance protocols to ensure that data of known and adequate quality are
generated and that the results are defensible.
NSF International (NSF), in cooperation with the EPA, operates the Water Quality Protection
Center (WQPC), one of six Centers under ETV. Source Water Protection (SWP) is one area
within the WQPC. The WQPC-SWP evaluated the performance of the Waterloo Biofilter
Systems, Inc. (WBS) Waterloo Biofilter® Model 4-Bedroom (Biofilter®) for the reduction of
nitrogen compounds (TKN, NH3, NO2, NO3), present in residential wastewater. WBS sells the
Biofilter® to treat wastewater from single-family homes. Other models of the Biofilter® are
available fcr small commercial businesses, and similar applications, but this evaluation does not
address those models. The unit is designed to work in conjunction with conventional septic tank
systems and to provide nitrogen reduction in addition to the removal of crganics and solids
present in these wastewaters. The Biofilter® system is based on fixed film trickling filter
technology, using a patented aerobic foam medium. This report provides the verification test
results for the WBS Waterloo Biofilter® Model 4-Bedroom System, in accordance with the
Protocol for the Verification for Residential Wastewater Treatment Technologies for Nutrient
Reduction, November 2000^.
1.2 Testing Participants and Responsibilities
The ETV testing of the Biofilter® was a cooperative effort between the following participants:
NSF International
Massachusetts Alternative Septic System Test Center
Barnstable County Department of Health and Environment Laboratory
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Groundwater Analytical, Inc.
Scherger Associates
Waterloo Biofilter Systems, Inc.
EPA
1.2.1 NSF International - Verification Organization (VO)
The Water Quality Protection Center of the ETV is administered through a cooperative
agreement between EPA and NSF International (NSF). NSF is the verification partner
organization for the WQPC and the Source Water Protection (SWP) area within the center. NSF
administers the center, and contracts the Testing Organization to develop and implement the
Verification Test Plan (VTP).
NSF's responsibilities as the Verification Organization included:
• Review and comment on the site specific VTP;
• Coordinate with peer-reviewers to review and comment on the VTP;
• Coordinate with the EPA Project Manager and the technology vendor to approve the
VTP prior to the initiation of verification testing;
• Review the quality systems of all parties involved with the Testing Organization and
subsequently, qualify the companies making up the Testing Organization;
• Oversee the technology evaluation and associated laboratory testing;
• Carry out an on-site audit of test procedures;
• Oversee the development of a verification report and verification statement;
• Coordinate with EPA to approve the verification report and verification statement;
and,
• Provide QA/QC review and support for the TO
Key contacts at NSF for the Verification Organization are:
Mr. Thomas Stevens, Program Manager
(734) 769-5347 email: stevenst@nsf.org
Ms. Maren Roush, Project Coordinator
(734) 827-6821 email: mroush@nsf.org
NSF International
789 N. Dixboro Road
Ann Arbor, Michigan 48105
(734)769-8010
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1.2.2 U.S. Environmental Protection Agency
The EPA Office of Research and Development, through the Urban Watershed Management
Branch, Water Supply and Water Resources Division, National Risk Management Research
Laboratory (NRMRL), provides administrative, technical, and quality assurance guidance and
oversight on all ETV Water Quality Protection Center activities. The EPA reviews and approves
each phase of the verification project. The EPA's responsibilities with respect to verification
testing include:
• Verification Test Plan review and approval;
• Verification Report review and approval; and,
• Verification Statement review and approval.
The key EPA contact for this program is:
Mr. Ray Frederick, Project Officer, ETV Water Quality Protection Center
(732)-321-6627 email: frederick.ray@epa.gov
U.S. EPA, NRMRL
Urban Watershed Management Branch
2890 Woodbridge Ave. (MS-104)
Edison, NJ 08837-3679
1.2.3 Testing Organization
The Testing Organization (TO) for the verification testing was the Barnstable County
Department of Health and Environment (BCDHE). Mr. George Heufelder of the BCDHE was
the project manager. He had the responsibility for the overall development of the Verification
Test Plan (VTP), oversight and coordination of all testing activities, and compiling and
submitting all of the test information for development of this final report.
Mr. Dale Scherger of Scherger Associates was contracted by NSF to work with BCDHE to
prepare the Verification Report (VR) and Verification Statement (VS).
The BCDHE Laboratory and its subcontractor, Groundwater Analytical, Inc. (GAI), provided
laboratory services for the testing program and consultation on analytical issues addressed during
the verification test period.
The responsibilities of the TO included:
• Prepare the site specific Verification Test Plan;
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• Conduct Verification Testing, according to the Verification Test Plan;
• Install, operate, and maintain the Biofilter® in accordance with the Vendor's
O&M manual(s);
• Control access to the area where verification testing was carried out;
• Maintain safe conditions at the test site for the health and safety of all personnel
involved with verification testing;
• Schedule and coordinate all activities of the verification testing participants,
including establishing a communication network and providing logistical and
technical support on an "as needed" basis;
• Resolve any quality concerns that may be encountered and report all findings to
the Verification Organization;
• Manage, evaluate, interpret and report on data generated by verification testing;
• Evaluate and report on the performance of the technology; and,
• If necessary, document changes in plans for testing and analysis, and notify the
Verification Organization of any and all such changes before changes are
executed.
The key personnel and contacts for the TO are:
Mr. George Heufelder, Project Manager
Barnstable County Department of Health and the Environment
Superior Court House (P.O. Box 427)
Barnstable, MA 02630
(508)375-6616
Email: gheufeld@capecod.net
Mr. Sean Foss, Facility Operations Manager:
Barnstable County Department of Health and the Environment
Superior Court House (P.O. Box 427)
Barnstable, MA 02630
(508)563-6757
Email: sfoss@capecod.net.
Dr. Thomas Bourne, Laboratory Manager
Barnstable County Department of Health and the Environment Laboratory
Superior Court House (P.O. Box 427)
Barnstable, MA 02630
(508) 375-6606
Email: bcdhelab@cape.com
1-4
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Mr. Eric Jensen
Groundwater Analytical, Inc. (GAI)
228 Main St.
Buzzards Bay, MA 02532
(508)759-4441
Scherger Associates was responsible for:
• Preparation of the Verification Report; and,
• Preparation of the Verification Statement
The key contact at Scherger Associates is:
Mr. Dale A. Scherger
Scherger Associates
3017 Rumsey Drive
Ann Arbor, MI 48105
(734)213-8150
Email: Daleres@aol.com
1.2.4 Technology Vendor
The nitrogen reduction technology evaluated was the Waterloo Biofilter® Model 4-Bedroom
System manufactured by WBS. WBS was responsible for supplying all of the equipment needed
for the test program, and supporting the TO in ensuring that the equipment was properly installed
and operated during the verification test. Specific responsibilities of the vendor include:
• Initiate application for ETV testing;
• Provide input regarding the verification testing objectives to be incorporated into
the Verification Test Plan;
• Select the test site;
• Provide complete, field-ready equipment and the operations and maintenance
(O&M) manual(s) typically provided with the technology (including instructions
on installation, start-up, operation and maintenance) for verification testing;
• Provide any existing relevant performance data for the technology;
• Provide assistance to the Testing Organization on the operation and monitoring of
the technology during the verification testing, and logistical and technical support
as required;
• Review and approve the site-specific VTP;
• Review and comment on the Verification Report; and,
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• Provide funding for verification testing.
The key contact for WBS is:
Dr. E. Craig Jewett, Ph.D., P.Eng.
Waterloo Biofilter Systems, Inc.
143 Dennis Street, P.O. Box 400
Rockwood, Ontario, NOB 2K0 Canada
(519)856-0757
(519) 856-0759 (Fax)
Email: craig@waterloo-biofilter.com
1.2.5 ETV Test Site
The Massachusetts Alternative Septic System Test Center (MASSTC) was the host site for the
nitrogen reduction verification test. MASSTC was initially funded by the State of Massachusetts.
The Barnstable County Department of Health and the Environment operates and provides the
staff for the center. The MASSTC is located at Otis Air National Guard Base, Bourne, MA. The
site was designed as a location to test septic treatment systems and related technologies.
MASSTC provided the location to install the technology and all of the infrastructure support
requirements to collect domestic wastewater, pump the wastewater to the system, operational
support, and maintenance support for the test. Key items provided by the test site were:
• Logistical support and reasonable access to the equipment and facilities for sample
collection and equipment maintenance;
• Wastewater that is "typical" domestic, relative to key parameters such as BODs TSS,
Total Nitrogen, and phosphorus;
• A location for sampling of raw or screened wastewater and a sampling arrangement to
collect representative samples;
• Automatic pump systems capable of controlled dosing to the technology being
evaluated to simulate a diurnal flow variation and to allow for stress testing.
Sufficient flow of wastewater to accomplish the required controlled dosing pattern;
• An accessible but secure site to prevent tampering by outside parties; and,
• Wastewater disposal of both the effluent from the testing operation and for any
untreated wastewater generated when testing is not occurring.
1.2.6 Technology Panel
Representatives from the Technology Panel assisted the Verification Organization in reviewing
and commenting on the Verification Test Plan.
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1.3 Background - Nutrient Reduction
Domestic wastewater contains various physical, chemical and bacteriological constituents, which
require treatment prior to release to the environment. Various wastewater treatment processes
exist which provide for the reduction of oxygen demanding materials, suspended solids and
pathogenic organisms. Reduction of nutrients, principally phosphorus and nitrogen, has been
practiced since the 1960's at treatment plants where there is a specific need for nutrient reduction
to protect the water quality and, hence, the uses of the receiving waters, whether ground water or
surface water. The primary reasons for nutrient reduction are to protect water quality for
drinking water purposes (drinking water standards for nitrite and nitrate have been established),
and to reduce the potential for eutrophication in nutrient sensitive surface waters by the reduction
of nitrogen and/or phosphorus.
The reduction of nutrients in domestic wastewater discharged from single-family homes, small
businesses and similar locations within watersheds is desirable for the same reasons as for large
treatment facilities. First, reduction of watershed nitrogen inputs helps meet drinking-water
quality standards for nitrate and nitrite; and second, the reduction of both nitrogen and
phosphorus helps protect the water quality of receiving surface and ground waters from
eutrophi cation and the consequent loss in ecological, commercial, recreational and aesthetic uses
of these waters.
Several technologies and processes can remove nutrients in on-site domestic wastewater. The
Biofilter® process is based on the fixed film (trickling filter) biological process for nitrification
and the anoxic conditions in the septic tank for biological denitrification. A brief discussion of
these processes is given below.
1.3.1 Fixed Film Trickling Filter - Biological Nitrification
The EPA has published a fact sheet describing the nitrification process in trickling filter systems,
Wastewater Technology Fact Sheet Trickling Filter Nitrification, EPA September 2000^. This
fact sheet provided the information presented below. A more comprehensive source of
information is the EPA Manual for Nitrogen Control (EPA/625/R-93/010/3).
Nitrification is a process carried out by bacterial populations (Vitrosomonas and Nitrobacter)
that oxidize ammonium to nitrate with intermediate formation of nitrite. These organisms are
considered autotrophic, because they obtain energy from the oxidation of inorganic nitrogen
compounds. The two steps in the nitrification process and their equations are as follows:
1) Ammonia is oxidized to nitrite (NCV) by Nitrosomonas bacteria.
2 NH4+ + 3 02 =2 N02" + 4 Yt + 2 H20
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2) The nitrite is converted to nitrate (NO3") by Nitrobacter bacteria.
2 N02 " + 02 = 2 N03 =
Since complete nitrification is a sequential reaction, systems must be designed to provide an
environment suitable for the growth of both groups of nitrifying bacteria. These two reactions
essentially supply the energy needed by nitrifying bacteria for growth. Several major factors
influence the kinetics of nitrification, including organic loading, hydraulic loading, temperature,
pH, and dissolved oxygen concentration.
1. Organic loading: The efficiency of the nitrification process is affected by the organic
loadings. Although the heterotrophic biomass is not essential for nitrifier attachment, the
heterotrophs (organisms that use organic carbon for the formation of cell tissue) form
biogrowth to which the nitrifiers adhere. The heterotrophic bacteria grow much faster
than nitrifiers at high BOD5 concentrations. As a result, the nitrifiers can be over grown
by heterotrophic bacteria, which can cause the nitrification process to cease. Before
nitrification can take place, the soluble BOD must be sufficiently reduced to eliminate
this competition, generally down to 20-30 mg/L.
2. Hydraulic loading: Wastewater is normally introduced at the top of the attached growth
reactor and trickles down through a medium. The value chosen for the minimum
hydraulic loading should ensure complete media wetting under all influent conditions.
Hydraulic and organic loadings are not independent parameters, because the wastewater
concentration entering the plant cannot be controlled. The total hydraulic flow to the filter
can be controlled to some extent by recirculation of the treated effluent. Recirculation
also increases the instantaneous flow at points in the filter and reduces the resistance to
mass transfer. This also increases the apparent substrate concentration and the growth and
removal rate. The third major benefit of recirculation in nitrifying trickling filters is the
reduction of the influent BOD5 concentration, which makes the nitrifiers more
competitive. This in turn increases the nitrification efficiency and increases the dissolved
oxygen concentration.
3. Temperature: The nitrification process is very dependent on temperature and occurs over
a range of approximately 4 to 45 °C (39 to 113 °F). Typically, at temperatures below 10
°C, nitrification rates slow dramatically, and may stop altogether at around 5 °C. Above
10 °C, the nitrification rate increases with temperature, and reaches a maximum at 30 to
35 °C. Higher nitrification rates are expected to be more affected by temperature than
lower rates of nitrification.
4. pH: The nitrification process produces acid. The acid formation lowers the pH and can
cause a reduction in the growth rate of the nitrifying bacteria. The optimum pH for
Nitrosomonas and Nitrobacter is between 7.5 and 8.5. At a pH of 6.0 or less nitrification
normally will stop. Approximately 7.1 pounds of alkalinity (as CaCOs) are destroyed per
pound of ammonia oxidized to nitrate.
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5. Dissolved Oxygen (DO): The concentration of dissolved oxygen affects the rate of
nitrifier growth and nitrification in biological waste treatment systems. The DO
concentration at which nitrification is limited can be 0.5 to 2.5 mg/L in either suspended
or attached g"owth systems under steady state conditions, depending on the degree of
mass-transport or diffusional resistance and the solids retention time. The maximum
nitrifying growth rate is reached at a DO concentration of 2 to 2.5 mg/L. However, it is
not necessary to grow at the maximum growth rate to get effective nitrification if there is
adequate contact time in the system. As a result there is a broad range of DO values
where DO becomes rate limiting. The intrinsic growth rate of Nitrosomonas is not limited
at DO concentrations above 1.0 mg/L, but DO concentrations greater than 2.0 mg/L may
be required in practice. Nitrification consumes large amounts of oxygen with 4.6 pounds
of O2 being used for every pound of ammonia oxidized.
1.3.2 Biological Denitrification
Denitrification is an anoxic process where nitrate serves as the source of oxygen for bacteria and
the nitrate is reduced to nitrogen gas. Denitrifying bacteria are facultative organisms that can use
either dissolved oxygen or nitrate as an oxygen source for metabolism and oxidation of organic
matter. If both dissolved oxygen and nitrate are present, the bacteria will tend use the dissolved
oxygen first. Therefore, it is important to keep dissolved oxygen levels as low as possible.
Another important aspect of the denitrification process is the presence of organic matter to drive
the denitrification reaction. Organic matter can be in the form of raw wastewater, methanol,
ethanol, or other organic sources. When these sources are not present, the bacteria may depend
on internal (endogenous) carbon reserves as organic matter. The endogenous respiration phase
can sustain a system for a time, but may not be a consistent enough source of carbon to drive the
reaction to completion or to operate at the rates needed to remove the elevated nitrate levels
present in nitrified effluent.
The denitrifying reaction using methanol as a carbon source can be represented as follows:
6N03= + 5CH3OH = 5C02 + 3N2 + 7H20 + 60H"
Several conditions affect the efficiency of the denitrification process including the anoxic
conditions, the temperature, presence of organic matter, and pH.
1. Dissolved oxygen - The level of dissolved oxygen has a direct impact on the denitrifying
organisms. As dissolved oxygen increases, denitrification rate decreases. Dissolved
oxygen concentrations below 0.3-0.5 mg/L in the anoxic zone are typically needed to
achieve efficient denitrification.
2. Temperature affects the growth rate of denitrifying organisms with higher growth rates
occurring at higher temperatures. Denitrification normally occurs between 5 and 35 °C
(41 to 95 °F). As in the case of nitrification, denitrifying rates drop significantly as
temperature falls below 10 °C.
1-9
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3. Organic matter - The denitrification process requires a source of organic matter.
Denitrification rate varies greatly depending upon the source of available carbon. The
highest rates are achieved with addition of an easily assimilated carbon source such as
methanol. Somewhat lower denitrification rates are obtained with raw wastewater or
primary effluent as the carbon source. The lowest denitrification rates are observed with
endogenous decay as the source of carbon.
pH and alkalinity - The optimum pH range for most denitrifying systems is 7.0 to 8.5. The
process will normally occur in a wider range, pH 6 - 9, but denitrifying rates may be
impacted near the extremes of the range. Acclimation of the population can lower the impact
of pH on growth rates. An advantage of the denitrification process is the production of
alkalinity that helps buffer the decrease in alkalinity in the nitrification process.
Approximately 3.6 pounds of alkalinity is produced for each pound of nitrate nitrogen
removed.
1-10
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2.0 Technology Description and Operating Processes
2.1 Technology Description
The WBS Waterloo Biofilter® System uses a fixed film trickling filter process in conjunction
with a conventional septic tank for wastewater treatment. The septic tank provides solid liquid
separation and anaerobic conditions for organic treatment and denitrification The trickling filter
consists of a bed of highly permeable and absorbent media over which wastewater is applied and
allowed to trickle through, providing aerobic conditions for organic removal and nitrification.
The Biofilter® uses a patented foam material as the medium. Microorganisms present in the
wastewater attach inside the media, and use the nitrogen and organic materials provided by the
constant supply of fresh wastewater to form new cell mass. The open spaces between the media
pieces allow air to freely pass through the bed, providing oxygen to support the microorganisms.
In the trickling filter, the organic material in the wastewater is degraded by microorganisms
attached to the media in the form of a biological film. According to WBS, the upper 40 cm of the
medium typically provides most of the treatment for solids and organics. The lower section of
the filter provides conditions conducive to growth of nitrifying organisms. Nitrogen compounds,
organic nitrogen and ammonia, are converted to nitrite and nitrate in the lower section of the
Biofilter®. A portion of the treated effluent (approximately 50 percent of flow) is recycled to the
septic tank to enhance the removal of nitrogen by reduction of the nitrate under anoxic
conditions in the septic tank.
2.2 Waterloo Biofilter® Equipment and Process Description
A complete treatment system has two stages of treatment. Raw sewage flows to the septic tank
where it undergoes initial organics treatment and separation of solids and liquids. The septic tank
effluent drains by gravity through an effluent screen into a pump chamber, normally constructed
below grade near the septic tank. The effluent screen is designed to ensure that large solids
remain in the septic tank and do not clog the pump or the nozzles downstream. The screened
effluent is pumped from the pump chamber to the Biofilter® unit using an on demand approach
(i.e., the pump activates when there is a rise in the pump chamber due to incoming flow.)
The Biofilter® unit consists of the foam medium supplied as two to three inch cubes piled
randomly into two self-contained baskets. The system relies on natural air circulation through the
bed to supply oxygen to the biomass. No fan is used to supply air to the unit. The baskets are
housed in a free draining shed with vents to allow natural air convection through the foam
medium. The container box had two openings for air exchange that were supplied with a small
amount of activated charcoal for odor control. The carbon filter was a loosely packed meshed
placed in the conduit between the inside and outside of the housing unit. The outside opening
had a screen affixed to it to prevent the intrusion of insects. The bag could be slid in/out from
the inside. These carbon filters were apparently adequate to control odor as no discernable odors
were noted during the test period. A neoprene seal between the hinged top of the foam filter and
the container itself likewise prevented escape of odor.
2-1
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The Biofilter® Design, Installation, and Service Manual (Appendix A) lists several alternative
containment systems for the foam medium, including below grade systems. Distribution nozzles
spray the wastewater over the foam surface. The bottom of the container is partitioned to allow
approximately 50 percent of the flow to return to the septic tank by gravity. The remaining 50
percent of flow is discharged by gravity from the system. In a normal installation, the discharge
water flows to a tile field or other suitable disposal location. For this test, the treated effluent
discharged through a sampling location, and then to the base sewer system.
Figures 2-1 through 2-3 show the basic system flow diagram and schematic representation of the
Biofilter® system. The system operated for this test is designed to handle 440 gpd. Additional
detailed information on the unit is presented in the Design, Installation, and Service Manual in
Appendix A.
In a typical residential application, raw wastewater flows by gravity into a 1,200 to 1,500 gallon,
two-compartment septic tank. The tank is baffled so that the flow does not channel directly
through the tank and to promote settling of solids. The system tested in this verification uses a
1,500 gallon single compartment primary tank. All Biofilter® Systems use an effluent screen on
the gravity discharge from the septic tank. Residential applications use a Zabel Model A 300
effluent filter attached to the outlet pipe of the septic tank to prevent solids from entering the
pump chamber. The filter provides one-eighth to one-sixteenth inch (1/8 - 1/16) screening of the
septic effluent.
The standard design for the pump chamber is a narrow diameter (18 to 24 inch) chamber that
receives the screened effluent. The pump chamber for the test unit was 20 inches in diameter.
The effluent pump is located on a slab to raise it off the floor. The on demand system uses two
pump control switches, with the lower on-off switch operating the pump. The lower switch is set
so that only approximately 23 liters (6 gallons) is dosed to the Biofilter® at any time. The upper
switch is the high water alarm with no over ride capability. This alarm activates if the water is
accumulating in the chamber due to pump failure, clogging of the nozzles, or if the incoming
flow rate exceeds the pumping rate.
The key, according to WBS, to the Biofilter® high efficiency is the absorbent foam medium,
which allows bacterial-microbial growth on the interior surfaces of the foam where they are
protected and can grow out into the large open pore spaces in the foam. Wastewater slowly
percolates down through the foam pieces and out the bottom. The unit for the ETV test consisted
of two 44-inch diameter by 54-inch high PVC coated, wire mesh baskets, containing a total of
95.4 ft3 (2.7 m3) of two to three inch foam cubes. The design loading rate was 4.6 US gpd/ft3(foam)
at an influent dosing rate of 440 gallons per day. The baskets were housed in a free-draining
wooden waterproof (cedar and pressure treated wood) shed with vents to allow natural air
convection through the foam medium. The shed was insulated with waterproof hardened foam
insulation. The bottom of the shed has a floor that was partitioned to send approximately half of
the treated water from each basket back to the inlet to the septic tank. The balance of the treated
water discharged by gravity through the sampling station.
2-2
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Process Schematic for Waterloo Biofilter®
Treatment System: Sample Residential System
Wire Mesh Baskets
Influent
Access
Riser
Effluent Filter
~i—r
Of1
Septic tanks w/ >2 days Demand
retention time Pump Chamber
Blofllter Unit:
Wire Mesh Baskets Placed
in Buried Tank or Above Ground
Shed
Note: The test unit had a return line to carry 50 percent of the treated effluent
back to the primary tank by gravity flow.
Effluent Pumped or
Gravity Fed to Disposal
Area
Not to Scale
Heather Millar
June 2002
Figure 2-1. Waterloo Biofilter" Schematic Representation
2-3
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Waterloo Biofilter Class 4 Tertiary
Models 11 and 16
(18"-24" diam tank for demand dosing)
attach float tree to wall chain (or pump lift
Concrete Septic Pump Tank
(to Biolilter)
Figure 2-2. Waterloo Biofilter System Pump Chamber
outer
basket
mesh
2" pvc40 outlet to
disposal with
optional 50% split
to septic tank
1" pvc40
hinged manifold
Insulated
lid
splash fabric
blofUter basket
1* pvc40
from septic
pump
chamber
Above Ground Insulated Waterloo Biofilter® Unit
(8'x4'x5' 600 gpd or 8'x4'x4' 480 gpd)
Basket and Manifold Plumbing Detail
helical spray
nozzle with sa
Figure 2-3. Waterloo Biofilter Filter Schematic
2-4
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The wastewater was pumped to the Biofilter® through 1 inch schedule 40 PVC pipe to a
manifold with downward facing nozzles. The two nozzles (one over each basket) are standard
fire sprinkler type nozzles, which distribute the spray over the foam in an even manner. The
distribution system is sized to provide 10-15 psi at the nozzle head.
The Biofilter® Design, Installation, and Service Manual (Manual) provides additional details for
the system and alternative configurations. A copy of the Manual is presented in Appendix A.
2.3 Equipment Specifications
The specifications for the Waterloo Biofilter® System are summarized in Table 2-1. All of the
piping used in the systems is either schedule 40 PVC pipe or flexible hose.
Table 2-1. Waterloo Biofilter® Specifications
Item
Quantity
Zabel A 300 effluent filter
1
Grundfos pump EF33 1/3 hp 110 VAC
1
Float switches
2
PVC distribution system
1
Bete fog nozzles
2
Wire mesh baskets 44" D x 54"H
2
Foam medium
95.4 ft3
Wooden shed (8'L X 4'W X 5'H)
1
Control panel
1
Technical Manual
1
Padlocks
1
Key
1
2.4 Operation and Maintenance
WBS provides an informational booklet to homeowners with important information about the
Biofilter® System. The Design, Installation, and Service Manual is provided to installers and
service companies. A copy of this Manual is presented in Appendix A. The Manual provides
installation, startup, operation and maintenance descriptions for the unit. WBS also provides a
Maintenance Checklist, a set of maintenance procedures, and troubleshooting information. These
lists are also presented in Appendix A. WBS strongly recommends that a service contract be
arranged with a local company to provide periodic maintenance for their units. The homeowners
booklet states that service should be performed at least annually, but the example service contact
in the Manual recommends twice per year.
2-5
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The semi-annual maintenance procedures recommended in the maintenance program include:
• Check pump and pump chamber
• Check that the pump control and alarm switches operate properly
• Check and clean spray nozzles
• Check condition of biomass and foam medium
• Check the quality of the effluent (visual, odor)
• Check control panel
• Inspect the septic tank
2.5 Vendor Claims
Waterloo Biofilter Systems, Inc. (WBS) claims the Waterloo Biofilter® System can be designed
to consistently remove nitrogen in wastewater on a year round basis. For a normal household,
WBS claims effluent quality is less than 15 mg/L CBOD5, less than 10 mg/L total suspended
solids, and 20-60 percent reduction of total nitrogen. Using a 50 percent recirculation flow, WBS
claims the total nitrogen removal can be increased to 50-60 percent on a healthy septic tank.
WBS literature claims that foam filter medium has a life span of 20 to 30 years, and normally
does not require cleaning for 10 years of operation. The foam medium life span was not part of
this verification.
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3.0 Methods and Test Procedures
3.1 Verification Test Plan and Procedures
A Verification Test Plan (VTP) was prepared and approved for the verification of the Waterloo
Biofilter Systems, Inc., Waterloo Biofilter® Model 4-Bedroom System, and is included in
Appendix B. The VTP, Test Plan for The Massachusetts Alternative Septic System Test Center
for the Verification Testing of the Waterloo Biofilter® Nutrient Reduction Technology
February 2001 detailed the procedures and analytical methods to be used to perform the
verification test. The VTP was prepared in accordance with the SWP protocol, Protocol for the
Verification of Residential Wastewater Treatment Technologies for Nutrient Reduction
November 2000. The VTP included tasks designed to verify the nitrogen reduction capability of
the Biofilter® unit and to obtain information on the operation and maintenance requirements of
the Biofilter®. There were two distinct phases of fieldwork to be accomplished as part of the
VTP, startup of the unit, and a one year verification test that included normal dosing and stress
conditions. The Protocol requires twelve months of sampling, however, an extra month was
added since the testing ended in a cold weather month (March). The extra one-month of data was
collected to show the response of the system coming out of a cold weather period.
Each of the testing elements, performed during the technology verification, is described in this
section. In addition to descriptions of sample collection methods, equipment installation, and
equipment operation, this section also describes the analytical protocols. Quality Assurance and
Quality Control procedures and data management approach are discussed in detail in the VTP.
3.2 MASSTC Test Site Description
The MASSTC site is located at Otis Air National Guard Base in Bourne, Massachusetts. The site
is designed to provide domestic wastewater for use in testing various types of residential
wastewater treatment systems. The domestic wastewater source is the sanitary sewerage from the
base residential housing and other military buildings. The sewer system for the base flows to an
on-base wastewater treatment facility. An interceptor chamber, located in the main sewer line to
the base wastewater treatment facility was constructed when the MASSTC was built, and
provides a location to obtain untreated wastewater. The raw wastewater passes through a bar
screen (grate) located before the transfer pump. This bar screen has one inch spacing between the
bars to remove large or stringy materials that could clog the pump or lines. The screened raw
wastewater is pumped through an underground two-inch line to the dosing channel at the test
site. The design of the interceptor chamber provides mixing of the wastewater just ahead of the
transfer pump to ensure a well-mixed raw wastewater is obtained for the influent feed at the test
site.
The screened wastewater is pumped to the dosing channel at a rate of approximately 29 gallons
per minute (gpm) on a continuous basis for 18 hours per day, yielding at total flow of
approximately 31,000 gallons per day (gpd). Wastewater enters the dosing channel, an open top
concrete channel, sixty-five feet long by two feet wide by three feet deep, via two pipes midway
in the channel. Approximately 4-6,000 gallons per day is withdrawn for test purposes in various
3-1
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treatment units. The excess wastewater flows by gravity to the base sanitary sewer and is treated
at the base wastewater treatment plant. The dosing channel is equipped with four recirculation
pumps. These pumps, spaced along the channel length, keep the wastewater in the channel
constantly moving to ensure the suspension of solids, and to ensure that the wastewater is of
similar quality at all locations along the channel.
Dosing of wastewater to the individual test units is accomplished by individual pumps
submerged in-line along the dosing channel. The pumps are connected to the treatment
technology being tested by underground PVC pipe. A custom designed, programmable logic
controller (PLC) is used to control the pumps and the dosing sequence or cycle. Each technology
feed pump can be controlled individually for multiple start and stop times, and for pump run
time. For the Biofilter® system, the volumetric dosages were set to meet the dosing sequence
described in the VTP. The test for the Biofilter® system was based on dosing 15 times per day
with approximately 29 gallons of wastewater per dose. This dosing volume of 440 gallons per
day was based on the Biofilter® rated capacity of 440 gpd. The individual dose volume was
controlled by adjusting the pump run time for each cycle.
MASSTC maintains a small laboratory at the site to monitor basic wastewater treatment
parameters. Temperature, dissolved oxygen, pH, specific conductance, and volumetric
measurements are routinely performed to support the test programs at the site. These field
parameters were performed at the site during the Biofilter® test.
The MASSTC has been in operation since 1999. Screened wastewater quality has been
monitored as part of several previous test programs, as presented in Table 3-1. Influent
wastewater monitoring was part of the startup and verification testing, and is described later in
this section. Results of all influent monitoring during the verification test are presented in
Chapter 4.
Table 3-1. Historical MASSTC Wastewater Data
Parameter
Average
Standard
(mg/L)
Deviation
bod5
180
61
TSS
160
59
Total Nitrogen
34
4.6
Alkalinity
170
28
pH
7.4
0.13
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3.3 Installation and Startup Procedures
3.3.1 Introduction
WBS provided a Design, Installation, and Service Manual for the Biofilter®. This Manual is
presented in Appendix A. The Biofilter® system had been installed at MASSTC in May 1999 as
part of an on-going testing program. The existing system, a single compartment, 1,500 gallon
septic tank, pump chamber, and a Biofilter® unit, were used for the startup and verification tests
for the ETV program.
3.3.2 Objectives
The objectives of the installation and start-up phase of the VTP were to:
• Install the WBS Biofilter® in accordance with the Manual;
• Start-up and test the Biofilter® to ensure all processes were operating properly, the pump
was set for proper automatic operation, and any leaks that occurred during the installation
were eliminated;
• Make any modifications needed to achieve operation; and,
• Record and document all installation and start-up conditions prior to beginning the
verification test.
3.3.3 Installation and Startup Procedures
The installation of the Biofilter® was performed by a contractor under the supervision of the
BCDHE support team and supported by the WBS staff. The installation was performed in May
1999 as part of an earlier test program. In order to prepare for startup of the Biofilter® for the
ETV verification, the entire Biofilter® system was emptied of wastewater and cleaned in
December 2000. Solids were removed from the primary tank, and all pumps, lines, and
associated equipment were cleaned. The foam media in the filter was removed and replaced with
new media. At the end of the cleaning period, the system was in a "like new" condition.
The VTP and Protocol allow for an eight-week startup period. During the startup, the biological
community is established and operating conditions are adjusted, if needed, for site conditions.
The startup procedures in the Manual (Appendix A) were followed as written. The primary tank
and filter system were filled with water and each component of the system checked for proper
operation. The water was also used to check the dosing pump flow rates.
Startup of the cleaned Biofilter® system began on January 15, 2001. Raw wastewater from the
dosing channel was added to the primary tank until it was full, resulting in a mixture of fresh
water and raw wastewater in the tank.. The dosing sequence was started on January 15 with a
setting of 15 doses of wastewater per day, with a target of 29.33 gallons of wastewater per dose.
This dose setting provided a target total daily flow of 440 gallons per day.
3-3
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The system was monitored during the startup period (January 15 through March 12, 2001) by
visual observation of the system, routine calibration of the dosing system, and the collection of
influent and effluent samples. Samples for analysis were collected six times over the eight week
startup period. Influent samples were analyzed for pH, alkalinity, temperature, BOD5, TKN,
NH3, and TSS analyses. The effluent was also analyzed for pH, alkalinity, temperature, CBOD5,
TKN, NH3, TSS, dissolved oxygen, NO2, and NO3. Procedures for sample collection, analytical
methods, and other monitoring procedures were the same procedures used during the one-year
verification period. These procedures are described later in this section.
3.4 Verification Testing - Procedures
3.4.1 Introduction
The verification test procedures were designed to verify nitrogen reduction by the WBS
Biofilter® treatment technology. The verification test consisted of a thirteen-month test period,
incorporating five stress periods with varying stress conditions simulating real household
conditions. Dosing volume was set based on the design capacity of the Biofilter® system.
Monitoring for nitrogen reduction was accomplished by measurement of nitrogen species (TKN,
NH3, NO2, NO3). Carbonaceous oxygen demand (CBOD) and other basic parameters (pH,
alkalinity, TSS, Temperature) were monitored to provide information on overall treatment
performance. Operational characteristics such as electric use, residuals generation, noise and
odor were also monitored.
Verification results and observations are presented in Chapter 4 of this Verification Report.
3.4.2 Objectives
The objectives of the verification test were to:
• Determine nitrogen reduction performance of the Biofilter® system;
• Monitor removal of other oxygen-using contaminants (BOD5 CBOD5 TSS);
• Determine operation and maintenance characteristics of the technology; and,
• Assess chemical usage, energy usage, generation of byproducts or residuals, noise and
odors.
3.4.3 System Operation- Flow Patterns and Loading Rates
The flow and loading patterns used during the thirteen-month verification test were designed in
accordance with the Protocol, as described in the VTP (Appendix B). The flow pattern was
designed to simulate the flow from a "normal" household. Several special stress test periods
were also incorporated into the test program.
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3.4.3.1 Influent Flow Pattern
The influent flow dosed to Biofilter® was controlled by the use of timed pump operation. The
dosing pump was set to provide 15 doses of equal volume (target - 29.3 gallons per dose) in
accordance with the following schedule:
• 6 a.m. - 9 a.m. approximately 33 percent of total daily flow in 5 doses
• 11 a.m. - 2 p.m. approximately 27 percent of total daily flow in 4 doses
• 5 p.m. - 8 p.m. approximately 40 percent of total daily flow in 6 doses
The influent dosing pump was controlled by a programmable logic controller, which permitted
timing of the fifteen individual doses to within one second. The pump flow rate and time setting
was calibrated by sequencing the dosing pump for one cycle and collecting the entire volume of
flow in a "calibrated" barrel. The barrel was initially calibrated by placing measured volume of
water into it. The dosing flow volume was checked by this calibration method at least twice per
week. Calibration results were recorded in the field logbook.
The initial total daily flow to the Biofilter® was targeted to be 440 gallons per day (29.3 gallons
per dose). After each calibration test, the measured volume was compared to this target rate. If
the volume was more than 10 percent above or below the target, the pump run time was
increased or decreased to adjust the volume per dose back to the target volume. If the run time
was changed, then a second calibration was performed to determine the total volume for the new
timer setting. The QC requirement for the dosing volume was 100 ± 10 percent of the target
flow (440 gallons per day) based on a thirty (30) day average, with the exception of periods of
stress testing. All calibration tests were recorded in the field logbook.
In addition to the twice weekly direct calibrations, the PLC system results were checked on a
daily basis. The PLC system recorded the number of doses delivered each day for each pump
operated by the system. The PLC was checked to confirm that 15 doses were delivered each day.
The PLC was also checked to ensure that the start and stop times were set properly. Any changes
made to the settings or problems with dose cycles were recorded on the log.
Flow information was entered into a spreadsheet that showed each day of operation, the pump
run time, the gallons pumped per dose, and the number of doses delivered to the unit.
3.4.3.2 Stress Testing Procedures
One stress test was performed during the verification test following every two months of
operation at the normal design loading. Five stress scenarios were run during the thirteen month
evaluation period. These special tests were designed to test the Biofilter® response to differing
load conditions and a power/equipment failure.
Stress testing included the following simulations:
• Washday stress
• Working Parent stress
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• Low Load stress
• Power/Equipment Failure stress
• Vacation stress
Washday stress simulation consisted of three (3) washdays in a five (5) day period, with each
washday separated by a 24-hour period of dosing at the normal design loading rate. During a
washday, the system received the normal flow pattern; however, during the course of the first
two (2) dosing periods per day, the hydraulic loading included three (3) wash loads [three (3)
wash cycles and six (6) rinse cycles]. The volume of wash load flow was 28 gallons per wash
load. The hydraulic loading rate was adjusted so that the loading on washdays did not exceed the
design loading rate. Common detergent (Arm and Hammer Fabri-care) and non-chlorine bleach
was added to each wash load at the manufacturer recommended amount.
The Working Parent stress simulation consisted of five (5) consecutive days when the Biofilter®
was subjected to a flow pattern where approximately 40 percent of the total daily flow was dosed
between 6 a.m. and 9 a.m., and approximately 60 percent of the total daily flow was dosed
between 5 p.m. and 8 p.m. This simulation also included one (1) wash load [one (1) wash cycle
and two (2) rinse cycles] during the evening dose cycle. The hydraulic loading did not exceed the
design loading rate during the stress test period.
The Low Load stress simulation consisted of testing the unit at 50 percent of the target flow (220
gallons per day) loading for a period of 21 days. Approximately 35 percent of the total daily
flow was dosed between 6 a.m. and 11 a.m., approximately 25 percent of the flow was dosed
between 11 a.m. and 4 p.m., and approximately 40 percent of the flow was dosed between 5 p.m.
and 8 p.m.
The Power/Equipment Failure stress simulation consisted of a standard daily flow pattern until 8
p.m. on the day when the Power/Equipment Failure stress is initiated. Power to the Biofilter®
was turned off at 9 p.m. and the flow pattern was discontinued for 48 hours. After the 48-hour
period, power was restored and the system dosed with approximately 60 percent of the total daily
flow over a three (3) hour period, which included one (1) wash load [one (1) wash cycle and two
(2) rinse cycles].
The Vacation stress simulation consisted of a flow pattern where, on the day that the stress is
initiated, approximately 35 percent of the total daily flow was dosed between 6 a.m. and 9 a.m.
and approximately 25 percent of the total daily flow was received between 11 a.m. and 2 p.m.
The flow pattern was discontinued for eight (8) consecutive days, with power continuing to be
supplied to the technology. Between 5 p.m. and 8 p.m. of the ninth day, the technology was
dosed with 60 percent of the total daily flow, which included three (3) wash loads [three (3) wash
cycles and six (6) rinse cycles].
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3.4.3.3 Sampling Locations. Approach, and Frequency
3.4.3.3.1 Influent Sampling Location
Influent wastewater was sampled from the dosing channel at a point near the Biofilter® dosing
pump intake, approximately four to six inches from the channel floor. The influent sampling site
selection was based on the layout of the dosing channel at the MASSTC facility. Screened
wastewater enters the sixty-five foot long dosing channel via two pipes midway between the
channel end and the channel outlet. Dosing pumps for individual systems are located in-line
along the dosing channel. The influent wastewater-sampling site was located close to the WBS
Biofilter® dosing pump to ensure a representative sample of wastewater was obtained.
3.4.3.3.2 WBS Biofilter® Effluent Sampling Location
For the Biofilter® effluent, the sampling site was located in the distribution box where the
effluent pipe from the Biofilter® discharges. During installation and setup of the Biofilter®, a
sampling point, consisting of a tee-cross with sump of sufficient size to retain sample volume for
both grab and automated sampler, was installed in the effluent pipe. The sump was only large
enough to retain approximately one liter of fluid and was readily flushed and replenished by the
normal flow of treated effluent. The sump was located so that it could be cleaned of any attached
and settled solids. Cleaning of the sampling location, by brushing to remove any accumulated
solids, was performed on a regular basis prior to each sampling period.
3.4.3.3.3 Sampling Procedures
Both grab and 24-hour flow weighted composite samples were collected at the influent and
effluent sampling locations. Grab samples were collected from both locations for the
measurement of pH and temperature. Dissolved oxygen was measured at the treated effluent
location when flow across the sampling point was occurring. The grab samples were collected by
dipping a sample collection bottle into the flow at the same location as the automatic sampler
used for composite sample collection. The sample bottle was labeled with the sampling location,
time and date. All pH and temperature measurements were performed at the on-site laboratory
immediately after sample collection.
Composite samples were collected using automated samplers at each sample collection point.
The automated samplers were programmed to draw equal volumes of sample from the waste
treatment stream at the same frequency and timing as influent wastewater doses. Samples taken
in this manner were therefore flow proportional. The effluent sampler timing was delayed to
correspond to the passage of a flow pulse through the Biofilter® system based on the influent
dosing pump timer setting. The automatic samplers were calibrated before each use and the
volume of sample collected was checked to ensure that the proper number of individual samples
was collected in the composite container. Detailed sampling procedures are described in the
MASSTC SOPs (Appendix C).
Table 3-2 shows a summary of the sampling matrix for the verification test.
3-7
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Table 3-2. Sampling Matrix
Sample Location
PARAMETER
SAMPLE
TYPE
INFLUENT
FINAL
EFFLUENT
TESTING
LOCATION
BOD5
24 Hour
composite
a/
Laboratory
CBODs
24 Hour
composite
a/
Laboratory
Suspended Solids
24 Hour
composite
a/
A/
Laboratory
pH
Grab
a/
A/
Test Site
Temperature (°C)
Grab
a/
A/
Test Site
Alkalinity (as
CaC03)
24 Hour
composite
A/
A/
Laboratory
Dissolved Oxygen
Grab
A/
Test Site
TKN (as N)
24 Hour
composite
A/
A/
Laboratory
Ammonia (as N)
24 Hour
composite
A/
A/
Laboratory
Total Nitrate(as N)
24 Hour
composite
A/
Laboratory
Total Nitrite (as N)
24 Hour
composite
A/
Laboratory
3.4.3.3.4 Sampling Frequency
Table 3-3 shows a summary of the sampling schedule followed during the test. Sample
frequency followed the VTP, and included sampling under design flow conditions on a monthly
basis and more frequent sampling during the special stress test periods.
Normal Monthly Frequency
Samples of the influent and effluent were collected once per month for the thirteen-month test
period (March 2001 - April 2002). The initial VTP was designed for a twelve-month test
program; however, the test period was extended for one additional month to provide data for the
month of April when temperatures were expected to be higher.
3-8
-------
Stress Test Frequency
Samples were collected on the day each stress simulation was initiated and when approximately
50 percent of each stress sequence was completed. For the Vacation and Power/Equipment
failure stresses, there is no 50 percent sampling. Beginning twenty-four (24) hours after tie
completion of Washday, Working Parent, Low Load, and Vacation stress scenarios, samples
were collected for six (6) consecutive days. Beginning forty-eight (48) hours after the
completion of the Power/Equipment Failure stress, samples were collected for five (5)
consecutive days.
Final Week
Samples were also collected for five (5) consecutive days at the end of the yearlong evaluation
period.
The decision was made to extend the test period of one additional month to monitor changes in
the system that would be influenced by the temperature of the wastewater. Therefore, there was
one additional set of samples (April 17, 2002) collected after the five-day sampling of the "final
week."
3.4.3.3.5 Sample Handling and Transport
Samples collected in the automatic samplers were collected with ice surrounding the sample
bottle to keep the sample cool. The composite sample container was retrieved at the end of the
sampling period, shaken vigorously, and poured into new bottles that were labeled for the
various scheduled analysis. Sample bottles used for TKN and ammonia analyses were supplied
by the laboratory with preservative. Sample container type, sample volumes, holding times, and
sample handling and labeling procedures were detailed in the VTP (Appendix B) and in the
MASSTC SOP, Attachment I (Appendix C).
BCDHE personnel transported the samples to the BCDHE laboratory via automobile. The
samples were packed in coolers with ice to maintain the temperature of all transported samples at
4 °C. Subsample containers analyzed at the GAI laboratory were transported from BCDHE
laboratory to GAI by GAI personnel. Travel time to BCDHE was approximately 40 minutes.
Travel time from BCDHE to GAI was approximately 45 minutes.
3-9
-------
Table 3-3. Sampling Schedule for Waterloo Biofilter® System
Monlh/l)av
Sampling Kvenl
Jan 23 and 31, 2001
Startup - 2 sampling events
February 14 and 28, 2001
Startup - 2 sampling events
March 7 and 13, 2001
Startup - 2 sampling events
March 21, 2001
Normal monthly sample
April 18, 2001
Normal monthly sample
May 8,10, and 13-18, 2001
Washday stress - 8 samples
June 6, 2001
Normal monthly sample
July 3, 2001
Normal monthly sample
July 10 and 13-20, 2001
Working Parent stress - 8 samples
August 1, 2001
Normal monthly sample
September 5, 2001
Normal monthly sample
September 18, 27 and
Low Load stress - 8 Samples
October 9-14, 2001
October 31, 2001
Normal monthly sample
November 28, 2001
Normal monthly sample
December 3, and 9-13, 2001
Power/Equipment Failure stress - 6 samples
December 28, 2001
Normal monthly sample
January 16, 2002
Normal monthly sample
February 4 and 14-19, 2002
Vacation Stress - 7 samples
March 4-8, 2002
Final week sampling - 5 samples
April 17, 2002
Additional monthly sample
3.4.3.4 Residuals Monitoring and Sampling
Byproducts or residuals generated by the Biofilter® system are returned to the primary tank, as
part of the return flow from the unit. Solids settle in this tank and accumulate slowly over time.
Measurements of solids depth in the primary tank were made twice near the end of the testing
period, in the thirteenth and fourteenth months after startup. A coring solids measurement tool
(Core Pro) was used to estimate the depth of sludge/solids and the scum layer in the 1,500 gallon
primary tank. The sampling device is a clear tube with a check valve on the bottom. The tube is
pushed through the solids to the bottom of the tank. The valve closes and the entire sample
column, water and solids, are removed from the tank. The column height is checked to ensure
that no sample has leaked from the device. The solids depth is then determined by measuring the
height of the solids in the clear tube using a tape measure or ruler. This approach gives a direct
measurement of the depth of solids. The thickness of any scum layer present is measured by ruler
or tape also. Three measurements of solids depth were made at each of the two access manholes.
Samples of solids were recovered from the Core Pro during the final measurement period by
emptying the probe contents into a clean container and sending the sample to the BCDHE
laboratory for VSS and TSS analysis. This sample included both the solids and the water present
in the tube. Thus, the concentration measurements for solids represent the concentration as if the
3-10
-------
entire contents of the tank were mixed. To estimate the solids concentration in the settled
material at the bottom of the tank, the depth of solids and the depth of water column need to be
accounted for, and the ratio used to calculate an estimated solids percent.
3.4.4 Analytical Testing and Record Keeping
As shown in Table 3-3, fifty-three (53) samples of the influent and effluent for the Biofilter®unit
were collected over the thirteen-month verification period. Table 3-2 presented the parameter
list. Samples included grab and composite samples for each sampling day. Industry standard
procedures (EPA Methods (5'6) or Standard Methods (7)) were used for all sample analysis. The
methods used for each constituent are shown in Table 3-4. Temperature, dissolved oxygen and
pH were measured onsite. All other analyses were performed by off site laboratories. The
Barnstable County Department of Health and Environment Laboratory performed the analyses
for alkalinity, total suspended solids, biochemical oxygen demand (BOD5), carbonaceous
biochemical oxygen demand (CBOD5), nitrite, and nitrate. Groundwater Analytical, Inc. (GAI)
was responsible for the analyses for Total Kjeldahl Nitrogen and ammonia.
Table 3-4. Summary of Analytical Methods and Precision and Accuracy Requirements
I'll r.i 111c lor
I'iicililx
AiTcpliincc
(riU'riii
Acccpliincc
Crili'riii
An;il\lii'iil Method
Duplicates (%)
Spikes (%)
PH
On-site
N/A
N/A
SM #423
Temperature (°C)
On-site
N/A
N/A
SM #2550
Dissolved Oxygen
On-site
N/A
N/A
SM #4500
Suspended Solids
BCDHE Laboratory
80-120
N/A
SM #2540 D
CBOD5
BCDHE Laboratory
80-120
N/A
SM #5210 B
Alkalinity
BCDHE Laboratory
80-120
N/A
SM #2320
Total Nitrite (as N)
BCDHE Laboratory
90-110
60-140
EPA 353.3
Total Nitrate (as N)
BCDHE Laboratory
90-110
60-140
EPA 353.3
TKN (as N)
GAI Laboratory
80-120
80-120
EPA 351.4
Ammonia (as N)
GAI Laboratory
80-120
80-120
EPA 350.1
SM - Standard Methods - 19th Edition
A Quality Assurance Project Plan was developed as part of the VTP, and provided quality
control requirements and systems to ensure the integrity of all sampling and analysis. Precision
and accuracy limits for the analytical methods are shown in Table 3-4. The QAPP included
procedures for sample chain of custody, calibration of equipment, laboratory standard operating
procedures, method blanks, corrective action plan, etc. Additional details are provided in the
VTP (Appendix B). Three laboratory audits were also performed during the verification test to
confirm that the analytical work was being performed in accordance with the methods and the
established QC objectives.
3-11
-------
The results of all analyses from the off site laboratories were reported to the TO by hardcopy
laboratory reports. The laboratory data are presented in Appendix D. The off site laboratories
also provided QA/QC data for the data sets. This data is included in Appendix D with the
laboratory reports. The on site laboratory maintained a laboratory logbook to record the results of
all analyses performed at the site. Copies of the on-site laboratory logbook are presented in
Appendix E.
The data received from the laboratories were summarized in an Excel spreadsheet by BCDHE
personnel at the test site. The data were checked against the original laboratory reports by the site
staff, and were checked by NSF to ensure the data was accurately entered. The spreadsheets are
included in Appendix F.
3.4.5 Operation and Maintenance Performance
Both quantitative and qualitative performance of the Biofilter® unit was evaluated during the
verification test. A field log was maintained that included all observations made during the
startup of the unit and throughout the verification test. Observations regarding the condition of
the system, any changes in setup or operation (influent wastewater timer adjustments, nozzle
cleaning, etc.), or any problems that required resolution were recorded in the log by the field
personnel.
Observation and measurement of operating parameters included electric use, chemical use, noise,
odor, and evaluation of mechanical components, electrical/instrumentation components, and by-
product volumes and characteristics.
3.4.5.1 Electric Use
Electrical use was monitored by a dedicated electric meter serving the WBS Biofilter®. The
meter reading was recorded biweekly in the field log by BCDHE personnel. The meter
manufacturer and model number and any claimed accuracy for the meter was recorded in the
Field Log. At the end of the testing period, the electric meter was returned to the manufacturer
for calibration and the calibration data entered in the Field Log.
3.4.5.2 Chemical Use
For this ETV testing, the Biofilter® did not use any process chemicals to achieve treatment.
3.4.5.3 Noise
Noise levels associated with mechanical equipment were measured once during the verification
period, using a decibel meter to measure the noise level. Measurements were taken one meter
from the unit and one and a half meters above the ground, at 90° intervals in four (4) directions.
The meter was calibrated prior to use. Meter readings were recorded in the field log. Duplicate
measurements at each quadrant were made to account for variations in ambient sound levels.
3-12
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3.4.5.4 Odors
Odor observations were made during the final eight months of the verification test. The
observation was qualitative based on odor strength (intensity) and type (attribute). Intensity was
stated as not discernable; barely detectable; moderate; or strong. Observations were made during
periods of low wind velocity (<10 knots). The observer stood upright at a distance of three (3)
feet from the treatment unit, at 90° intervals in four (4) directions. All observations were made
by the same BCDHE employee.
3.4.5.5 Mechanical Components
Performance and reliability of the mechanical components, such as wastewater pumps, were
observed and documented during the test period. These observations included recording in the
Field Log of equipment failure rates, replacement rates, and the existence and use of duplicate or
standby equipment.
3.4.5.6 Electrical/Instrumentation Components
Electrical components, particularly those that might be adversely affected by the corrosive
atmosphere of a wastewater treatment process, and instrumentation and alarm systems were
monitored for performance and durability during the course of verification testing. Observations
of any physical deterioration were noted in the Field Log. Any electrical equipment failures,
replacements, and the existence and use of duplicate or standby equipment were recorded in the
Field Log.
3-13
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4.0 Results and Discussion
4.1 Introduction
Evaluation of the WBS Biofilter® at MASSTC began on January 15, 2001. The unit was filled
with a mixture of fresh water and wastewater, the pumps were activated, and the initial dosing
cycles started. Flow was set at 440 gpd resulting in 15 doses per day, with a target 29.3 gallons
per dose. The startup period continued until March 12, 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.
This chapter presents the results of the sampling and analysis of the influent and effluent to/from
the unit, a discussion of the results, and observations on the operation and maintenance of the
unit during startup and normal operation. Summary of results are presented in these sections.
Complete copies of all spreadsheets with individual daily, weekly, or monthly results are
presented in Appendix F.
4.2 Startup Test Period
The startup period provided time for the Biofilter® to develop a biological growth acclimated to
the site-specific wastewater. The startup also provided an opportunity for the Biofilter® system to
be adjusted, if needed, to optimize performance at the site. These first eight weeks of operation
also provided site personnel an opportunity to become familiar with the Biofilter® operation and
maintenance requirements. Samples were collected during weeks 2, 3, 5, 7, and 8 (2 sets) of the
startup period.
4.2.1 Startup Flow Conditions
The flow conditions for the Biofilter® were established at the target capacity of 440 gallons per
day in accordance with the VTP. The dosing pump was set to deliver 15 doses per day at
approximately 29.3 gallons per dose. Five (5) doses were delivered between 6 a.m. and 9 a.m.,
four (4) doses between 11 a.m. and 2 p.m., and six (6) doses between 5 p.m. and 8 p.m. In early
September, it was discovered that a PLC problem resulted in the actual dosing rate being 14
doses per day, as the first dose each morning was not occurring. Thus, for the startup period and
approximately six months (March 13 to September 9) of the verification test, the unit received 14
doses per day, four (4) in the morning, four (4) mid day, and six (6) in the early evening. The
average flow for the startup period was 408 gpd, which was within the ± 10 percent (396-484
gpd) of the design flow on a monthly basis specified for the test. The volume of wastewater
dosed to the unit during the startup remained mostly constant and only minor adjustments to the
4-1
-------
dosing pump ran time were required. Table 4-1 shows a summary of the flow volumes during the
startup period. The daily flow records are in Appendix F.
Table 4-1. Flow - Volume Data during the Startup Period
Date Average Actual Daily Volume
Doses/day Gallons/dose (Gallons)
Jan 15-21
14
29.3
410
Jan 22 - 27
14
28.0
392
Jan 28 - Feb 6
14
29.5
413
Feb 7- 13
14
29.0
406
Feb 14-17
14
29.1
407
Feb 18-24
14
28.9
405
Feb 25 - Mar 3
14
30.0
420
Mar 4-6
14
28.5
399
Mar 7- 12
14
29.5
413
4.2.2 Startup Analytical Results
The results of the influent and effluent monitoring during the startup period are shown Tables 4-
2 and 4-3. The first sets of samples were taken seven days after the unit was started. The initial
data showed that the unit reduced the CBOD5 and TSS to 23 mg/L and 6 mg/L, respectively, and
the Biofilter® appeared to be removing some of the total nitrogen (34 mg/L in the influent, 18
mg/L in the effluent). Observations and additional sampling to determine the condition of the
unit continued for the next eight weeks. No adjustments to the system were made. The treatment
performance was lower in February with CBOD5 increasing in the effluent to as high as 58
mg/L.
At the end of the eight weeks allotted for the startup, the verification test period began. The
biological growth was not yet fully established or acclimated, as suggested by the elevated
CBOD5 in the effluent (48 to 66 mg/L). It is likely that the cold temperatures were slowing the
development and acclimation process. WBS literature indicates that with a winter startup,
nitrification can take several months to begin, but that once established nitrification will continue
through subsequent winters. The temperature of the incoming wastewater was about 4 to 8 °C
when the unit was started, and was 8 °C at the end of the startup period. Effluent temperature was
lower at 5 to 6 °C. As will be seen in the next section, the unit showed rapid improvement in
performance beginning in April and May when temperatures increased above 10 C.
4-2
-------
Table 4-2. Influent Wastewater Quality - Startup Period
Influent
Alkalinitv
BODs
DO
Ammonia
pH
TKN
TN
TSS
Temp.
Date
(mg/L)
(mg/L)
(mg/L)
(mg/L)
(S.U.)
(mg/L)
(mg/L)
(mg/L)
(°Q
01/23/01
180
150
0.2
26
7.6
34
34
120
8.2
01/31/01
170
280
1.2
24
7.2
41
41
280
8.0
02/14/01
190
180
N/S
26
7.5
42
42
190
N/S
02/28/01
200
200
0.8
28
7.7
46
46
190
7.1
03/07/01
160
180
1.4
23
7.4
34
34
130
7.4
03/13/01
180
160
1.1
25
7.4
40
40
130
7.8
N/S - no sample
Table 4-3. Waterloo Biofilter® Effluent Quality - Startup Period
Alkalinity
CBOD5
DO
Ammonia
Nitrate
Nitrite
pH
TKN
TN
TSS
Discharge
Date
(mg/L)
(mg/L)
(mg/L)
(mg/L)
(mg/L)
(mg/L)
(S.U.)
(mg/L)
(mg/L)
(mg/L)
Temp (°C)
01/23/01
180
23
5.5
24
<0.1
<0.05
7.6
18
18
6
3.8
01/31/01
190
24
3.6
25
<0.1
<0.05
7.5
31
31
7
8.0
02/14/01
200
45
7.5
28
<0.1
<0.05
7.7
39
39
22
5.0
02/28/01
200
58
00
00
28
<0.1
0.07
7.6
38
38
26
5.8
03/07/01
190
48
8.6
27
<0.1
0.09
7.9
34
34
25
5.2
03/13/01
190
66
8.4
26
<0.1
<0.05
7.8
36
36
39
5.4
4.2.3 Startup Operating Conditions
The Biofilter® system was started according to the Manual. The on-off switch for the pump was
set so that the pump would turn on and dose the media when the volume in the pump chamber
was about 6 gallons of water. Since the pump operated as an on-demand system, there was no
timer or automatic controls to set. The high water switch/alarm in the pump chamber was tested
and the unit was placed into service. The startup instructions in the Manual (Appendix A) were
easy to follow and provided the necessary instructions to get the unit up and operating. The
effluent recirculation rate was preset by the divider in the bottom of the enclosure at
approximately 50 percent for this evaluation.
No changes were made to the unit during the startup period. Regular observations showed that
biological growth was slowly being established on the media. No maintenance was required
during the startup period and there were no mechanical problems. Overall, the unit started up
with no mechanical difficulty.
4.3 Verification Test
4-3
-------
In accordance with the startup period set forth in the VTP and the Protocol, the verification test
was started officially on March 13, 2001. A final startup sample was collected on March 12-13.
All results for the balance of the test were considered part of the verification test period. The data
presented for the verification results do not include data from the startup period. As stated above,
there were no changes made to the basic operation of the system. All Biofilter® operating
parameters (pumps, alarms, etc.) remained the same as during the initial startup period.
4.3.1 Verification Test - Flow Conditions
The dosing sequence (15 doses per day, 29.3 gallons per dose) was performed every day from
March 13 through September 7, 2001, except during the stress periods. Volume per dose and
total daily volume varied only slightly during this period. In September, it was discovered that
while the PLC was set to deliver 15 doses per day and showed 15 doses being delivered, only 14
doses were actually being pumped to the unit. The first dose each morning was being missed
because of a timer issue with the start of wastewater flow at the test site. Beginning September 7,
2001, the problem was resolved and daily flow was dosed 15 times per day as originally
specified in the VTP. The lower flow being dosed to the unit for the first six months was still
within the specification that flow be ± 10 percent of the design flow on a monthly average basis
(design flow 440 gpd). Table 4-4 shows the average monthly volumes for the verification period.
As this data shows, the actual wastewater volume dosed to the Biofilter® was very close to the
targeted volume of 440 gallons per day for the last seven months of the test.
4-4
-------
Table 4-4. Waterloo Biofilter® Influent Volume Summary
Target
Ave Monthly
Mon/Year
Gallon/dose
Doses/day
Gallon/dose
Gallon/day
Mar-01
29.33
14
28.8
403
Apr-01
29.33
14
29.5
413
May-01
29.33
14
28.7
401
Jun-01
29.33
14
29.9
421
Jul-01
29.33
14
30.2
423
Aug-01
29.33
14
29.2
408
Sep-01
29.33
15(1)
28.7
426(2)
Oct-01
29.33
15
29.6
444(2)
Nov-01
29.33
15
29.1
436
Dec-01
29.33
15
29.0
435(3)
Jan-02
29.33
15
29.3
439
Feb-02
29.33
15
29.4
434(4)
Mar-02
29.33
15
29.2
438
Apr-02
29.33
15
28.9
433
Average
15
29.2
425
Maximum
30.2
444
Minimum
28.7
401
Std. Dev.
0.4
14
(1) The timer and PLC issue was fixed on September 6. Fifteen doses were
delivered beginning on September 7, 2001.
(2) September/October - Low Load test run in September and October; average
flow data for September and October does not include the low flow days. Only
normal flow days are included. During the Low Load test, flow was set at 50
percent of normal flow. Actual average flow during the Low Load test
(September 17 to October 7) was 219 gpd.
(3) December - Power/Equipment Failure Test - no flow one day, low flow on
second day. Average does not include the low/no flow days.
(4) February 2002 - Vacation test - 10-day test; no flow for 8 days,
Only nine doses on first and last day; Low or no flow days excluded from the
calculation of monthly averages
4.3.2 BOD5/CBOD5 and Suspended Solids Results
Figures 4-1 and 4-2 show the results for BOD5/CBOD5 and total suspended solids (TSS) in the
influent and effluent for the verification test. Table 4-5 presents same results with a summary of
the data (average, median, maximum, minimum, standard deviation). CBOD5 was measured in
the effluent as required in the Protocol. The use of the CBOD5 analysis was specified because the
effluent from nutrient reduction systems was expected to be low in oxygen demanding organics,
4-5
-------
and have a large number of nitrifying organisms, which can cause nitrification to occur during
the first five days of the test. The CBOD5 analysis inhibits nitrification during the analysis, and
provides a better measurement of the oxygen demanding organics in the effluent. The BOD5 test
was used for the influent, which had much higher levels of oxygen demanding organics, and was
expected to have a very low population of nitrifying organisms. In the standard BOD5 test, it is
assumed that little nitrification occurs within the five days of the test. Therefore, the oxygen
demanding organics are the primary compounds measured in the wastewater influent. Using the
BOD5 of the influent and the CBOD5 in the effluent should provide a good comparison of the
oxygen demanding organics removal of the system.
The verification test 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 the remaining months (monthly sampling). Therefore, impacts of the stress
test or an upset condition occurring during the concentrated sampling can have an impact on the
calculation of average values. Both average and median results are presented in Table 4-5, as the
median values compared to average values can help in analyzing these impacts. In the case of the
Biofilter® results, the effluent median values are lower than the average values due to the lower
performance that occurred immediately following the Vacation stress test (February 14 to 19,
2002).
The influent wastewater had an average BOD5 of 210 mg/L and a median BOD5 of 200 mg/L.
The average influent TSS was 150 mg/L with a median concentration of 130 mg/L. The
Biofilter® effluent showed an average CBOD5 of 10 mg/L and a median CBOD5 of 7.4 mg/L.
The effluent TSS concentration was 7 mg/L, with a median concentration of 5 mg/L. The
Biofilter® system averaged 95 percent reduction of BOD5/CBOD5 with a median removal of 96
percent. TSS removal averaged 95 percent over the thirteen-month period, with a median
removal of 97 percent. CBOD5 concentrations in the effluent typically ranged from 1 to 20 mg/L,
and TSS ranged from 1 to 10 mg/L, except for the first month after startup and for a short period
in February 2002.
At the end of the startup period, the Biofilter® system was reducing TSS and CBOD5, but had not
yet achieved the level of performance anticipated by WBS and conducive to the establishment of
nitrification. During the period of March 13 through April 18, 2001, wastewater effluent
temperature began to increase quickly (see Figure 4-7) and the effluent concentration of TSS and
CBOD5 began to trend lower. At the end of April, it was also noted that the media had "settled",
which was causing short-circuiting of the wastewater through the media. Checking the media
level is part of the recommended routine maintenance for the unit. Additional media was poured
into the top of the unit, as directed in the Manual. No additional media was needed or added for
the duration of the test.
By the start of the first stress test, (Washday stress), the unit was producing effluent
concentrations in the range of 7 to 18 mg/L for CBOD5 and 3 to 13 mg/L for TSS. The Washday
stress test was started on May 8 and concluded on May 11, with no significant impact on the
CBOD5 and TSS performance. Post stress period monitoring showed continued improvement in
4-6
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performance into June 2001. Both effluent CBOD5 and TSS were 15 mg/L or less during the
next two month period.
The Working Parent stress test was started on July 10 and was completed on July 13. By the start
of the stress test, the unit was showing CBOD5 and TSS below 10 mg/L. Performance continued
to be good during the stress test and there was no apparent change in the effluent quality. From
August 2001 through January 2002, the Biofilter® performance was consistent. Data collected
during the Low Load stress test in September/October and the Power/Equipment Failure test in
December showed no change in either CBOD5 or TSS performance.
Following the Vacation stress test in February 2002, there was an increase in effluent CBOD5
(16 to 27 mg/L range) and TSS (8 to 20 mg/L). These results are likely a result of the Vacation
stress test, but also coincide with the water temperature in the system effluent dropping to its
lowest point for the year (5 to 7 °C). During the Vacation stress test, there is an eight-day period
with no flow to the system, although power is maintained. The Biofilter® system only pumps
wastewater to the unit if there is a demand, so the biological growth on the media received no
flow for eight days. It is likely that this period of no flow, combined with the low outside air and
water temperatures, stressed the population. Whatever the cause of the increase in CBOD5 and
TSS in the effluent, the performance improved within two weeks of normal operation. By early
March, effluent CBOD5 and TSS were at or below 10 mg/L.
4-7
-------
CM
CM
CM
CM
CM
CM
CM
CM
O
O
O
O
O
O
O
O
5)
CO
-------
Low Load
Test
i
-- 50
-- 40
ui
E
w
t 30 w
-- 20
Vacation
Power Failure Test
Test
ui
Ł 200 -\
w
w
150 -
Workii^ Parent
Test '¦
Washday
Test
Date
Influent TSS Left Axis Effluent TSS Right Axis
Figure 4-2. Waterloo Biofilter® Total Suspended Solids Results
4-9
-------
Table 4-5. Waterloo Biofilter® BOD5/CBOD5 and TSS Results
BOD5
CBOD5
TSS
Influent
Effluent
Removal
Influent
Effluent
Removal
Date
(mg/L)
(mg/L)
(Percent)
(mg/L)
(mg/L)
(Percent)
03/21/01
150
43
71
63
19
70
04/18/01
130
36
72
110
55
51
05/08/01
150
7.1
95
120
13
89
05/10/01
120
16
87
150
3
98
05/13/01
340
18
95
250
9
97
05/14/01
320
18
94
190
7
96
05/15/01
67
9.9
85
190
11
94
05/16/01
86
7.0
92
200
7
96
05/17/01
170
12
93
92
3
97
05/18/01
170
18
90
90
7
92
06/06/01
300
12
96
210
7
97
07/03/01
290
6.7
98
210
4
98
07/10/01
160
2.3
99
230
3
99
07/13/01
200
5.1
97
250
2
99
07/15/01
99
3.1
97
120
5
96
07/16/01
210
4.5
98
340
3
99
07/17/01
180
6.3
96
320
11
97
07/18/01
240
15
94
260
2
99
07/19/01
300
19
94
260
6
98
07/20/01
320
3.5
99
200
5
98
08/01/01
110
4.0
96
96
4
96
09/05/01
190
20
89
61
5
92
09/18/01
330
2.0
99
150
1
99
09/27/01
250
8.6
97
260
4
98
10/09/01
210
6.0
97
170
3
98
10/10/01
260
4.2
98
150
3
98
10/11/01
200
5.3
97
120
<1.0
>99
10/12/01
300
4.1
99
120
1
99
10/13/01
260
5.2
98
130
2
99
10/14/01
260
2.0
99
100
1
99
4-10
-------
Table 4-5. Waterloo Biofilter® BOD5/CBOD5 and TSS Results (continued)
BOD5
CBOD5
TSS
Influent
Effluent
Removal
Influent
Effluent
Removal
(mg/L)
(mg/L)
(Percent)
(mg/L)
(mg/L)
(Percent)
10/31/01
250
3.1
99
96
2
98
11/28/01
240
2.7
99
190
3
98
12/03/01
160
5.1
97
190
1
99
12/09/01
110
3.1
97
120
2
98
12/10/01
150
<1.0
>99
170
2
99
12/11/01
120
2.4
98
140
2
99
12/12/01
130
1.9
99
95
2
98
12/13/01
170
3.1
98
91
2
98
12/28/01
170
3.6
98
130
1
99
01/16/02
250
4.4
98
140
3
98
02/04/02
370
4.4
99
130
8
94
02/14/02
270
24
91
160
17
89
02/15/02
330
19
94
220
11
95
02/16/02
250
27
89
130
9
93
02/17/02
220
16
93
130
20
84
02/18/02
210
18
91
100
10
90
02/19/02
220
16
93
190
8
96
03/04/02
180
8.2
96
100
5
95
03/05/02
170
7.2
96
76
7
91
03/06/02
180
8.1
95
78
8
90
03/07/02
200
10
95
87
7
92
03/08/02
180
8.2
95
81
3
96
04/17/02
260
9.5
96
130
10
92
Samples
53
53
53
53
53
53
Average
210
10
95
150
7
95
Median
200
7.4
96
130
5
97
Maximum
370
43
99
340
55
>99
Minimum
67
1
71
61
<1
51
Std. Dev.
73
9
6
66
8
8
Values below the detection limit are set to zero for concentration averages
Samples = Nurrber of samples collected or used in the calculations
4-11
-------
4.3.3 Nitrogen Reduction Performance
4.3.3.1 Results
Figures 4-3 through and 4-5 present the results for the TKN, ammonia, and total nitrogen (TN) in
the influent and effluent during the verification test. Figure 4-6 shows the results for nitrite and
nitrate in the effluent from the Biofilter® system. Table 4-6 presents all of the nitrogen results
with a summary of the data (average, median, maximum, minimum, standard deviation).
The influent wastewater had an average TKN concentration of 37 mg/L and an average ammonia
nitrogen concentration of 23 mg/L, with median concentrations of 37 mg/L and 23 mg/L,
respectively. Average TN concentration in the influent was 37 mg/L (median of 37 mg/L), based
on the generally accepted assumption that the nitrite and nitrate concentration in the influent was
negligible. The Biofilter® effluent had an average TKN concentration of 3.7 mg/L, with a
median of 1.6 mg/L. The average ammonia nitrogen concentration in the effluent was 2.4 mg/L,
with a median concentration of 0.7 mg/L. The nitrite concentration in the effluent averaged 0.19
mg/L, with a median concentration 0.14 mg/L. Effluent nitrate concentrations averaged 10 mg/L
over the thirteen-month test, with a median concentration of 10 mg/L. Total nitrogen was
determined by adding the concentrations of the TKN (organic plus ammonia nitrogen), nitrite
and nitrate, resulting in an average TN in the Biofilter® effluent of 14 mg/L for the thirteen
month verification period, with a median concentration of 13 mg/L. The Biofilter® system
averaged 62 percent reduction of TN for the verification test period, with a median removal of 65
percent.
Alkalinity, pH, dissolved oxygen (DO), and temperature were measured during the verification
test. These parameters can provide insight into the condition of the system and can impact total
nitrogen removal. Table 4-7 shows the results for alkalinity, DO, and pH. Temperature
measurements are shown in Figure 4-7 and Table 4-6.
The pH of the influent was very consistent throughout the test, ranging from pH 7.2 to 7.6. The
effluent from the Biofilter® showed a slight decrease in pH, but in a similar range, consistently
remaining in the pH 6.9 to 7.7 range. The alkalinity of the influent averaged 180 mg/L as CaC03
with a maximum concentration of 230 mg/L and minimum of 160 mg/L. The effluent alkalinity
was consistently lower than the influent (as expected when nitrification/denitrification is
occurring), with an average concentration of 82 mg/L and a median concentration 74 mg/L. The
only time the effluent alkalinity did not decrease by at least 25 percent was during the first weeks
after startup when the unit was not yet fully acclimated.
The Dissolved Oxygen in the influent wastewater was low, as would be expected. The average
DO in the influent was 0.3 mg/L, and was less than 1.0 mg/L on all but one day of testing. The
Biofilter® system is designed to operate as an aerobic system with the vents on the unit allowing
air to move through the media. The DO in the effluent from the Biofilter® was normally in the
range of 4 to 7 mg/L, and averaged 6.2 mg/L over the thirteen months of verification testing.
4-12
-------
4.3.3.2 Discussion
As discussed earlier in the startup section, at the end of the startup period (January 15 to March
12, 2001), the Biofilter® effluent was showing only negligible reduction of total nitrogen.
Influent and effluent wastewater temperatures were in the 4 to 8 °C range. As shown in Table 4-
6, beginning in late March and early April, the temperatures began to increase. There was some
indication that performance was improving, but CBOD5 was still at 36 mg/L. TKN and ammonia
concentrations were decreasing but performance was not at the level anticipated. In late April, it
was discovered that the foam media had settled in the baskets and the wastewater was short-
circuiting through the media. Media was added to the unit, as recommended in the Manual. With
the increasing temperatures and the elimination of the short-circuiting, the nitrifying population
clearly became established, as indicated by the decrease in the TKN and ammonia concentrations
in the effluent, and an increase in nitrate concentration. TN concentration in the effluent began to
decrease, indicating that the denitrification population was becoming established in the septic
tank. During May and June, the TN reduction was typically in 65 to 80 percent range. The
Washday stress test performed in May 2001 did not appear to have a negative impact on nitrogen
reduction. Overall, given the conditions during the startup, which began in January, the system
took approximately three to four months to develop a nitrifying and denitrifying population.
In July 2001, the Working Parent stress test was performed. The performance of the unit
remained steady during and following this stress period. The Biofilter® system continued to
reduce the total nitrogen concentration on a consistent basis (60-80 percent reduction) until
February 2002. During this period, which included the Low Load and Power/Equipment Failure
stress tests, nitrification was very effective, generally reducing the ammonia nitrogen and TKN
to less than 1 mg/L. The denitrification process during this period was also effective in
removing nitrate produced during the nitrification step, although nitrate removal was not as
efficient or complete as the nitrifying step. The total nitrogen in the effluent ranged from 6.2 to
14 mg/L during the August to December period.
The Vacation stress test was started on February 4 and was completed on February 13, 2002. The
sample taken before the stress test in early February showed some signs that denitrification
process was slowing down, while the nitrification process, as measured by TKN and ammonia,
was still consistent. Effluent CBOD5 concentrations were low at 4.4 mg/L. The results showed
somewhat higher effluent nitrate levels (increase from 10 to 15 mg/L), and TN removal was just
over 50 percent (17 mg/L in the effluent). Also, the alkalinity (Table 4-7) was slightly lower in
the effluent during this period. The lower alkalinity can be an indicator that the denitrification
process is slowing down, as the nitrification process consumes alkalinity (approximately 7.1 mg
for each mg of ammonia nitrogen removed), and the denitrification process produces alkalinity
(approximately 3.6 mg per mg nitrate nitrogen removed).
On the first day after the Vacation stress test ended, the effluent nitrate concentration jumped to
33 mg/L, and the effluent ammonia concentration was higher at 10 mg/L. Total nitrogen
increased to 45 mg/L, which was actually higher than the influent value of 35 mg/L. CBOD5 and
TSS also increased on the day after the stress test. It would appear that both the nitrification and
denitrification processes were impacted during this time. The lack of wastewater application to
the media (no flow for eight days) most likely had an impact on the biological population. The
4-13
-------
use of the "on-demand" pumping approach results in no application of wastewater to the
Biofilter® when there is no flow. Also, the timing of the Vacation stress test coincided with the
coldest time of the year, and the temperature of the effluent dropped to 5 °C from 7 °C on first
day after the Vacation stress period ended.
Performance began to improve almost immediately after the flow returned to normal conditions.
CBOD5 effluent concentrations began to trend downward and were below 10 mg/L within two
weeks. Ammonia nitrogen concentrations also began to trend downward and were in the 1-3
mg/L range within a few days. Nitrate concentrations decreased and total nitrogen removal
reached 50 percent by February 19. Temperature of the effluent continued to climb over the next
few weeks and the system performance continued to show improvement. The overall
performance of the system was slightly lower during the weeks following the Vacation stress test
(March 2002), as compared to the October to December 2001 period, showing effluent TN
concentrations of 15 to 17 mg/L versus 9 to 11 mg/L.
The last sample collected in April 2002 indicated that both the nitrifying and denitrifying
processes had recovered, resulting in an effluent TN concentration of 11 mg/L. TKN and
ammonia concentrations were 3.5 mg/L and 1.1 mg/L, respectively, only slightly higher than the
less 1 mg/L levels achieved in previous summer and fall periods. The nitrate concentration was
7.1 mg/L, which was actually on the low side of the levels found in the summer and fall.
Alkalinity was higher than in February and March, indicating that the denitrifying population
was active and adding to the alkalinity of the system.
The verification test provided a sufficiently long test period to collect data that included both a
long run of steady performance by the Biofilter® system and a period of an apparent upset
following the Vacation stress test. While the system appeared to be impacted by the Vacation
stress test and low temperatures, recovery was rapid, with TN removal on the order of 60 percent
(55-70 percent measured) being established within two to four weeks.
4-14
-------
T—
T—
T—
T—
T—
T—
T—
T—
T—
T—
T—
T—
T—
T—
T—
CM
CM
CM
CM
CM
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
O
o
o
O
T—
o
o
o
G)
5)
CD
CO
CO
CD
<3
CD
55
CD
LD
C\J
¦*—
CO
C\J
CD
CNj
¦*—
CO
C\J
¦*—
o
C\J
CN
C\J
¦*—
C\J
C\J
CO
55
CD
CO
o5
o
t-
C\J
C\J
CO
Date
Influent TKN
Effluent TKN
Figure 4-3. Waterloo Biofiltei® Total Kjeldahl Nitrogen Results
4-15
-------
T—
T—
T—
T—
T—
T—
T—
T—
T—
T—
T—
T—
T—
T—
T—
CM
CM
CM
CM
CM
o
o
o
o
o
o
o
o
o
o
O
o
o
o
o
o
o
o
o
O
T—
o
o
o
G)
o5
o5
CO
CO
CD
CD
CD
lB
CD
uo
C\J
CO
C\J
CD
C\J
CO
C\J
o
C\J
C\J
C\J
C\J
C\J
CO
LO
CO
h-
CO
CD
o
C\J
CM
CO
Date
Influent Ammonia Effluent Ammonia
Figure 4-4. Waterloo Biofiltei^ Ammonia Nitrogen Results
4-16
-------
¦ ¦ 'Influent TN
Effluent TN
Figure 4-5. Waterloo Biofiltei^ Total Nitrogen Results
4-17
-------
Washday
Test
Working
Parent
Low Load
Test
Power
Failure
Test
Vacation Test
i *1 '
1 ' | _
i
_ ¦ - +*
5.00
-- 4.50
-¦ 4.00
-¦ 3.50
"¦ 3.00 _
O)
+ 2 50 ~
0
U
-¦ 2.00 2
T—
T—
T—
T—
T—
T—
T—
T—
T—
T—
T—
T—
T—
T—
T—
CM
CM
CM
CM
CM
o
o
o
o
o
o
O
o
o
o
O
o
o
o
o
o
o
o
o
O
o
o
o
§>
o5
o5
CO
CD
CD
CD
55
CD
C\J
CO
C\J
CD
CNj
CO
C\J
o
C\J
C\J
CNj
CM
C\J
CO
55
CD
h-
CO
CD
¦*-
o
¦*—
¦*-
C\J
¦*-
CM
CO
Date
Effluent Nitrate Left Axis
• Effluent Nitrite Right Axis
Figure 4-6. Waterloo Biofiltei^ Nitrite and Nitrate Effluent Concentrations
4-18
-------
T—
T—
T—
T—
T—
T—
T—
T—
T—
T—
T—
t—
T—
T—
T—
CM
C\J
CM
CM
CM
o
o
o
o
o
o
o
o
o
o
O
o
o
o
o
o
o
o
o
O
o
o
o
G)
o5
o5
CO
CO
h-
CD
CD
CD
55
CD
UO
C\J
CO
C\J
CD
C\J
CO
C\J
o
c\i
C\J
C\J
C\J
C\J
CO
LO
CD
h-
00
CD
"5~
o
T—
"5~
C\J
T_
CM
CO
Eflfuent Discharge Temp (C)
Figure 4-7. Waterloo Biofiltei® Effluent Temperature
4-19
-------
Table 4-6. Waterloo Biofilter® Influent and Effluent Nitrogen Data
TKN
Ammonia
Total Nitrogen
Nitrate
Nitrite
Temperature
(ins
[/L)
(ms
[/L)
(ms
[/L)
(mg/L)
(mg/L)
CO
Date
Influent
Effluent
Influent
Effluent
Influent
Effluent
Effluent
Effluent
Influent
03/21/01
37
31
21
24
37
32
0.6
0.30
6.4
04/18/01
36
19
24
13
36
21
2.2
0.20
9.7
05/08/01
30
9.6
18
5.8
30
16
6.4
0.16
N/R
05/10/01
41
8.0
29
5.4
41
12
4.3
0.14
15
05/13/01
41
9.6
28
4.9
41
14
4.3
0.15
16
05/14/01
42
6.8
24
4.3
42
10
3.5
0.15
16
05/15/01
40
7.8
25
4.2
40
13
4.6
0.15
16
05/16/01
41
7.6
27
3.7
41
12
4.4
0.14
15
05/17/01
36
7.4
25
3.7
36
12
4.4
0.18
15
05/18/01
44
7.1
24
3.7
44
11
4.1
0.16
14
06/06/01
45
4.4
27
2.3
45
9
4.3
0.26
17
07/03/01
38
2.5
24
0.7
38
15
13
0.14
11
07/10/01
35
<0.5
21
0.5
35
13
13
0.07
24
07/13/01
34
4.1
18
2.3
34
12
7.8
0.12
22
07/15/01
36
<0.5
23
0.3
36
13
13
0.09
23
07/16/01
31
<0.5
20
<0.2
31
16
16
0.08
22
07/17/01
36
<0.5
22
<0.2
36
14
14
0.09
23
07/18/01
40
<0.5
24
0.3
40
14
14
0.06
23
07/19/01
42
<0.5
25
0.5
42
14
14
0.06
22
07/20/01
36
<0.5
24
0.5
36
15
15
0.07
22
08/01/01
29
<0.5
21
0.4
29
12
12
0.11
22
09/05/01
30
<0.5
19
0.6
30
13
12
0.29
23
09/18/01
34
<0.5
23
<0.2
34
14
14
<0.05
22
09/27/01
39
<0.5
22
<0.2
39
12
12
<0.05
22
10/09/01
24
0.9
20
0.3
24
10
9.0
0.07
18
10/10/01
30
0.6
21
0.2
30
6.8
6.2
<0.05
18
10/11/01
34
<0.5
21
0.3
34
8.9
8.6
<0.05
18
10/12/01
35
<0.5
21
0.2
35
8.7
8.4
<0.05
19
10/13/01
31
0.7
22
<0.5
31
9.0
8.3
<0.05
19
10/14/01
37
<0.5
25
0.6
37
9.1
00
00
<0.05
19
N/R - Not reported
4-20
-------
Table 4-6. Waterloo Biofilter® Influent and Effluent Nitrogen Data (continued)
TKN
Ammonia
Total Nitrogen
Nitrate
Nitrite
Temperature
(m
g/L)
(mg/L)
(m
g/L)
(mg/L
(mg/L)
(°C)
Date
Influent
Effluent
Influent
Effluent
Influent
Effluent
Effluent
Effluent
Influent
10/31/01
36
1.1
26
<0.2
36
9.3
8.2
<0.05
16
11/28/01
39
<0.5
26
<0.2
39
11
11
<0.05
14
12/03/01
36
1.3
24
0.4
36
9.5
8.1
0.07
14
12/09/01
34
<0.5
23
<0.2
34
13
13
<0.05
11
12/10/01
39
<0.5
23
<0.2
39
10
10
<0.05
12
12/11/01
38
<0.5
22
0.4
38
11
11
<0.05
12
12/12/01
36
<0.5
22
0.3
36
11
11
<0.05
12
12/13/01
41
<0.5
22
<0.2
41
10
9.9
<0.05
12
12/28/01
44
<0.5
27
0.4
44
10
9.5
0.23
8.3
01/16/02
38
2.4
25
1.7
38
13
10
0.77
7.2
02/04/02
36
1.6
23
1.5
36
17
15
0.32
7.0
02/14/02
35
11
21
10
35
45
33
0.60
5.2
02/15/02
44
6.7
22
2.3
44
25
17
0.84
6.0
02/16/02
37
6.4
25
4.6
37
18
11
0.74
N/R
02/17/02
37
6.8
22
3.3
37
17
9.2
0.65
6.7
02/18/02
35
6.8
23
3.5
35
17
9.9
0.55
6.8
02/19/02
39
4.1
22
1.8
30
15
11
0.47
6.7
03/04/02
37
3.7
26
2.5
37
16
12
0.41
8.3
03/05/02
38
3.1
22
1.8
38
15
12
0.38
7.5
03/06/02
36
3.5
23
2.2
36
16
12
0.29
7.7
03/07/02
37
3.8
21
1.8
37
16
12
0.30
8.2
03/08/02
39
4.6
24
2.4
39
17
12
0.26
8.4
04/17/02
38
3.5
23
1.1
38
11
7.1
0.19
14
Samples
53
53
53
53
53
53
53
53
51
Average
37
3.7
23
2.4
37
14
10
0.19
15
Median
37
1.6
23
0.7
37
13
10
0.14
15
Maximum
45
31
29
24
45
45
33
0.84
24
Minimum
24
<0.5
18
<0.2
24
6.8
0.6
<0.05
5.2
Std. Dev.
4.1
5.5
2.4
4.0
4.2
6.0
5.0
0.2
5.9
Values below the detection limit set equal to zero (0) for statistical calculations
N/R - not reported
Samples = Number of samples collected or used in the calculations
4-21
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Table 4-7. Waterloo Biofilter® Alkalinity, pH, and Dissolved Oxygen Results
Alkalinity
Dissolved Oxygen
PH
(mjj/L as CaCOj)
(mg/L)
(S.U.)
Date
Influent
Effluent
Influent
Effluent
Influent
Effluent
03/21/01
200
200
0.4
8.3
7.6
7.7
04/18/01
190
150
1.9
8.2
7.6
7.6
05/08/01
160
110
N/R
N/R
7.3
7.4
05/10/01
190
130
0.6
6.0
7.4
7.5
05/13/01
180
120
0.4
5.0
7.5
7.6
05/14/01
170
120
0.7
5.0
7.5
7.6
05/15/01
180
120
0.5
5.8
7.4
7.5
05/16/01
180
110
0.4
6.2
7.4
7.5
05/17/01
180
110
0.3
6.0
7.5
7.6
05/18/01
190
110
0.3
6.4
7.6
7.6
06/06/01
180
88
0.4
6.6
7.6
7.4
07/03/01
190
73
0.4
3.3
7.3
7.1
07/10/01
180
88
0.8
5.2
7.5
7.4
07/13/01
170
110
0.7
5.2
7.4
7.3
07/15/01
190
90
0.1
4.3
7.6
7.2
07/16/01
200
86
0.1
4.0
7.6
7.6
07/17/01
180
80
0.1
3.6
7.4
7.2
07/18/01
190
76
0.2
4.7
7.2
7.0
07/19/01
200
66
0.2
4.9
7.2
7.1
07/20/01
190
66
0.1
4.7
7.4
7.3
08/01/01
170
60
0.3
4.7
7.5
7.3
09/05/01
170
74
0.3
4.3
7.3
7.1
09/18/01
180
64
0.3
5.8
7.4
7.4
09/27/01
190
70
0.1
6.2
7.3
7.3
10/09/01
170
74
0.2
7.2
7.5
7.4
10/10/01
180
78
0.0
7.4
7.4
7.3
10/11/01
190
76
0.0
6.7
7.3
7.2
10/12/01
180
79
0.1
6.7
7.2
7.1
10/13/01
180
78
0.1
6.8
7.4
7.3
10/14/01
190
68
0.0
7.1
7.4
7.4
N/R - Not Reported
4-22
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Table 4-7. Waterloo Biofilter® Alkalinity, pH, and Dissolved Oxygen Results (continued)
Alkalinity
Dissolved Oxygen
PH
(mg/L as
CaCO,)
(mg/L)
(S.U.)
Date
Influent
Effluent
Influent
Effluent
Influent
Effluent
10/31/01
200
74
0.3
7.7
7.4
7.3
11/28/01
190
66
0.2
7.5
7.4
7.1
12/03/01
170
66
0.1
8.3
7.3
7.1
12/09/01
180
60
0.2
6.4
7.5
7.2
12/10/01
190
62
0.1
8.0
7.5
7.3
12/11/01
180
60
0.1
8.0
7.4
7.2
12/12/01
180
60
0.4
8.2
7.4
7.2
12/13/01
190
62
0.4
7.8
7.6
7.2
12/28/01
230
62
0.3
7.6
7.5
7.4
01/16/02
190
70
0.2
8.4
7.6
7.2
02/04/02
180
48
0.2
5.1
7.4
6.9
02/14/02
170
72
0.2
7.0
7.4
6.9
02/15/02
200
64
0.2
6.8
7.3
7.0
02/16/02
190
86
0.2
6.9
7.4
7.1
02/17/02
180
86
0.2
7.3
7.4
7.2
02/18/02
170
82
0.1
5.6
7.5
7.0
02/19/02
180
76
0.4
5.4
7.4
7.1
03/04/02
170
60
0.8
4.5
7.5
7.3
03/05/02
160
56
0.5
7.0
7.4
7.0
03/06/02
170
58
0.6
5.6
7.4
6.9
03/07/02
180
56
0.2
5.7
7.4
6.9
03/08/02
180
60
0.5
6.0
7.4
6.9
04/17/02
190
86
0.1
5.6
7.4
7.1
Samples
53
53
52
52
53
53
Average
180
82
0.3
6.2
n/c
n/c
Median
180
74
0.2
6.2
7.4
7.3
Maximum
230
100
1.9
8.4
7.6
7.7
Minimum
160
48
0.0
3.3
7.2
6.9
Std. Dev
11
27
0.3
1.3
n/c
n/c
n/c - not calculated
Samples = Number of samples collected or used in the calculations
4-23
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4.3.4 Residuals Results
During the treatment of wastewater in the Biofilter® system, solids accumulate in the primary
tank. Inert solids are removed in the primary tank system just as in a normal septic system.
Biological solids accumulate from the influent wastewater solids and from the recycle of effluent
solids (approximately 50 percent recycle rate of treated effluent), and any solids that might
slough from the media. Eventually, a buildup of solids reduces the capacity of the primary tank
and the solids will need to be removed.
The approximate quantity of the residuals accumulated in the system was estimated by
measuring the depth of solids in the primary tank. Measurement of solids depth was difficult in
the primary tank (septic tank), as access to the unit is limited to manways in the top of the unit.
Solids depth was estimated at three locations from each of the two manways using a Core Pro
solids-measuring device. A column of water and solids is removed from the tank, and the
undisturbed solids depth in the clear tube measured with a ruler. The measurements were made
three times, once in June 2001, and twice near the end of the test, in February 2002 and in March
2002. The results are presented in Table 4-8.
Table 4-8. Solids/Scum Depth Measurement
Primary l ank Solids/Scum Depth in Inches
\ Win why Location
luisl
Middle
West
A \ crauL'
June 20, 2001-Inlet
16
8
13
12
June 20, 2001 Outlet
6
10
19
12
June 20, 2002 Scum Depth Inlet
0
0
0
0
June 20, 2002 Scum Depth Outlet
0
0
0
0
February 4, 2002-Inlet
8
12
18
13
February 4, 2002-Outlet
12
7
7
9
February 4, 2002 Scum Depth Inlet
6
5
0
4
February 4, 2002 Scum Depth Outlet
7
4
6
6
March 8, 2002-Inlet
21
28
22
24
March 8, 2002-Outlet
9
10
9
9
March 8, 2002 Scum Depth Inlet
0
0
0
0
March 8, 2002 Scum Depth Outlet
7
4
6
6
Note: Measurement is estimated solids depth in the Primary Tank
4-24
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In order to characterize the solids in the primary tank, total suspended solids and volatile
suspended solids were measured in the samples collected in March. These data are presented in
Table 4-9. These concentrations represent the solids concentration in the total sample collected,
which includes the solids and water present in the sample tube. Based on an average of 16 inches
of solids present in the tube in March, and an additional 44 inches of water (60 inch total depth in
the septic tank), the concentration of solids must to be multiplied by a factor of 3.75 to estimate
the actual solids concentration in the settled solids layer.
Table 4-9. TSS and VSS Results for the Waterloo Biofiltei® Solids Sample
Dale
Location
TSS (ing/l.)
VSS (mg/L)
3/8/02
Primary Tank
6300
250
The mass of solids present in the septic tank can be estimated from these data. The average
concentration of solids in the septic tank, 6,300 mg/L multiplied by the tank total volume of
1,500 gallons shows that the solids accumulated during the test was approximately 78 pounds.
The total mass of solids can also be estimated using the settled solids concentration and the tank
dimensions. The primary tank holds a volume of approximately 25 gallons per inch of depth.
Therefore, the solids volume, based on an average 16 inches depth (March data), was about 400
gallons. The settled solids concentration is estimated to be 2.4 percent (24,000 mg/L) using the
ratio of total depth to solids depth described above (factor of 3.75). Based on a settled solids
concentration of 24,000 mg/L, the weight of dry solids accumulated was approximately 80
pounds. The volatile solids represented 4 percent of the salids in the tank according to the
laboratory results. These percentage of volatile solids seems very low, but could be checked or
confirmed as the system was emptied before the laboratory data was received.
4.4 Operations and Maintenance
Operation and maintenance performance of the Biofilter® unit was monitored throughout the
verification test. A field log was maintained that included all observations made over the
thirteen-month test period. Data was collected on electrical and chemical usage, noise, and odor.
Observations were recorded on the condition of the Biofilter®, any changes in setup or operation
(pump adjustments, nozzle cleaning, etc.) or any problems that required resolution. A complete
set of field logs is included in Appendix G.
4.4.1 Electric Use
Electrical use was monitored by a dedicated electric meter serving the Biofilter® system. The
meter reading was recorded biweekly in the field log by BCDHE personnel. Table 4-10 shows a
summary of the electrical use from startup through the end of the verification test. The complete
set of electrical readings is presented in a spreadsheet in Appendix F. The average electrical use
4-25
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was 1.3 kilowatts per day based on the entire data set. The basic system tested used only one
pump to dose the media and all other flow (recirculation, influent wastewater, effluent discharge)
was by gravity. The unit tested did not have a fan for supplemental air supply to the filter.
Options of adding a supplemental fan or the need to pump the discharge and/or recycle flow to
the primary tank, in certain applications, would increase the electrical use.
Table 4-10. Summary of Waterloo Biofilter® Electrical Usage
kW/day
Readings
188
Average
1.30
Maximum
2.50
Minimum
0.00
Std. Dev.
0.49
4.4.2 Chemical Use
The Biofilter® system did not require or use any chemical addition as part of the normal
operation of the unit.
4.4.3 Noise
Noise levels associated with mechanical equipment were measured once during the verification
period. A decibel meter was used to measure the noise level. Measurements were taken one
meter from the unit and one and a half meters above the ground, at 90° intervals in four (4)
directions. The meter was calibrated prior to use. Table 4-11 shows the results from this test.
Table 4-11. Waterloo Biofilter® Noise Measurements
Location
First Reading
(decibels)
Second Reading
(decibels)
Average
Background
37.5
38.0
37.7
Biofilter®
East
47.6
45.5
46.8
South
49.5
49.3
49.4
West
50.5
49.3
49.5
North
44.8
44.8
44.8
Decibels are a log scale so averages are calculated on a log basis
4-26
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4.4.4 Odor Observations
Monthly odor observations were made over the last eight months of the verification test. The
observation was qualitative based on odor strength (intensity) and type (attribute). Intensity was
stated as not discernable; barely detectable; moderate; or strong. Observations were made during
periods of low wind velocity (<10 knots). The observer stood upright at a distance of three (3)
feet from the treatment unit, and recorded any odors at 90° intervals in four (4) directions
(minimum number of points). All observations were made by the same BCDHE employee.
Table 4-11 summarizes the results for the odor observations. As can be seen, there were no
discernible odors found during any of the observation periods.
The container box had two openings for air exchange that were supplied with a small amount of
activated charcoal for odor control. The carbon filter was a loosely packed meshed placed in the
conduit between the inside and outside of the housing unit. The outside opening had a screen
affixed to it to prevent the intrusion of insects. The bag could be slid in/out from the inside.
These carbon filters were apparently adequate to control odor as no discernable odors were noted
during the test period. A neoprene seal between the hinged top of the foam filter and the
container itself likewise prevented escape of odor. During the operation of the system, the odor
of the media between doses (only discernable if the top was opened) was described as a mild
musty odor.
Table 4-12. Odor Observations
Date Number of Observation
Points observed
9/10/01
8 No discernable odor
10/20/01
8 No discernable odor
11/22/01
8 No discernable odor
12/09/01
8 No discernable odor
01/27/02
8 No discernable odor
02/17/02
8 No discernable odor
03/02/02
8 No discernable odor
03/31/02
8 No discernable odor
4.4.5 Operation and Maintenance Observations
The Waterloo Biofilter® is a trickling filter that uses as a proprietary open-cell foam media for
the growth of bacteria for treatment combined with bacteria resident in the septic tank. The
system is comprised of a septic tank, the filter media contained in baskets enclosed in an above
grade housing, and a pump chamber. The operation of the system as configured during the test
was by demand; that is, the activation of the pump serving the filter and the ultimate rate of
forward flow was determined by the rate of wastewater supplied to the septic tank.
4-27
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The operation of the system is described in detail in the Design, Installation and Service Manual
(Appendix A). Septic tank effluent is distributed over baskets containing the open-cell foam.
The bottom of the containers are partitioned to allow approximately 50 percent of the flow to
return to the septic tank, while approximately 50 percent of the flow proceeds by gravity directly
to the leaching facility or other distribution system (such as a pump chamber for low-pressure
distribution to a leach field). The Biofilter® System, as tested, had only one pump, two spray
nozzles, two level switches, a water level alarm, and a screen on the discharge from the septic
tank. Therefore, in the opinion of the operating staff, the system is fairly simple and
straightforward to operate and maintain (from a mechanical and electrical perspective).
During the test, very few problems were encountered with the operation of the system. The
screen on the outlet from the septic tank (influent to the pump chamber) required periodic
cleaning. During the test, the filter was cleaned after eight months (two months of startup and six
months of testing) in accordance with the WBS recommendation. No changes or adjustments
were needed to the float switches or the pump.
According to WBS, "after an initial period, which may extend approximately 2-6 months, likely
depending on the organic loading, the height of the foam media should be checked for settling.
This should not be confused with the start up period for performance, which is shorter in
duration. Excessive settling of the media may cause a short-circuiting of the wastewater flow
down the side of the container as the spray overtops the receded media. Foam media can easily
be added at any point to prevent or anticipate this problemThe foam media condition and
level was checked during the startup and periodically during the verification test. After
approximately four months of operation (January 15 to April 27), it was noted that the effluent
was somewhat cloudy and that the media had settled in the baskets. The settled media caused
short-circuiting to occur in the unit. WBS directed the MASSTC staff to add media to the unit to
fill the baskets. Media was added only once during the test.
During the test, the filter media was housed in a lined wooden box that was situated at least 80
percent above grade. The lining of the housing was comprised of waterproof hardened-foam
insulation. Insects, notably boring-type ants, were found to infest the material and bored many
tunnels in it, particularly in the top. Test Center personnel applied borax liberally in the area,
which resulted in a near eradication of the ants. The hinged top of the container allowed access,
but with use, the hinge arrangement proved inadequate as the fastening screws pulled out of the
side of the wooden box. A lockable hasp provided adequate security from unauthorized access.
The effluent distribution nozzles are of a standard fire-sprinkler design and did not clog or
prevent flow during the tests. Material exiting the orifice, however, did occasionally catch on the
distribution plate features and periodically altered the spray pattern slightly. Cleaning this feature
is a regular part of the maintenance of the system. The distribution plate was cleaned (a simple
wiping of the plate) on the average of about once per quarter. While the cleaning may not be
needed as frequently, checking and cleaning the plate on a regular basis to maintain an even flow
distribution will help maintain optimum performance. This task is something that a homeowner
could do in a few minutes time.
4-28
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In general, the clarity of the liquid effluent can be described as clear, occasionally having a slight
cloudy appearance. Any more extreme cloudiness signaled a problem, such as was observed
when the foam media subsided and some short-circuiting of effluent occurred.
In the opinion of the test site operators, the system was easy to operate and maintain. The
operators believe quarterly maintenance checks of the Waterloo Biofilter® would be adequate to
address any anticipated problems. WBS recommends a minimum of once per year maintenance
checks, and the sample maintenance contract is designed for twice per year maintenance of the
unit. Based on fifteen months of observation, it is estimated that quarterly maintenance checks,
requiring about one hour by a person knowledgeable of the system, would seem appropriate to
ensure the system is in good operating condition. The skill level needed is the equivalent of a
Class II Massachusetts treatment plant operator. It is possible that a knowledgeable homeowner
could perform certain routine quarterly checks, after the system has been in operation for several
months, and routinely checked by a trained operator. Homeowner involvement in routine
cleaning and system checks might be able to reduce the scheduled contractor maintenance to a
semi-annual frequency.
Maintenance activities should include checking the filter media for subsidence and adding media
as needed. The biomass condition and the clarity of the effluent should be observed. The nozzles
and distribution plates should be checked for clogging and be cleaned. The pump, alarms, and
floats should be checked for proper operation. The primary tank should be checked for solids
depth and the primary tank effluent screen (Zabel filter) should be cleaned. The activated carbon
located on the air openings will have a finite life, although the testing provided no guidance on
how long ihe carbon will last. It appears that carbon replacement should be part of routine
maintenance, but the carbon life maybe long, and replacement only needed if odor becomes a
problem.
The primary tank should be checked for solids depth and if solids have built up in the septic tank,
pumping of the septic tank should be scheduled. There is no guidance on the solids depth in the
septic tank that would indicate that the tank should be pumped. In a typical or standard
residential septic tank system pumping can be expected to occur every 3 to 5 years. More
frequent pumping of solids from the septic tank can be expected based on the additional solids
load generated by the Biofilter® System. The regular maintenance checks should include
measurement of solids level h the primary tank. When the level of solids buildup to 36 to 42
inches (60 inches of depth available to the outlet) in depth, the tank will need to be pumped to
ensure that good solids separation continues in the tank.
The verification test ran for a period of thirteen months, which provided sufficient time to
evaluate the overall performance of the unit. However, a much longer operational period would
be needed to determine any impacts that repeated sloughing of solids from the media might have
on the effluent loading to a receiving soil. The Biofilter® does not have a secondary clarifier or
settling zone to remove biomass present in the treated effluent during sloughing periods. Fifty
percent of the flow is returned to the primary tank, so during sloughing periods, half of the solids
would be removed in the primary tank and half of the solids would be discharged. It is not
4-29
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possible to determine what, if any, long-term impacts that sloughed solids will have on the
receiving soils. The Manual makes a statement that effluent samples collected from the system
should be taken so that "no sloughed biomass is included." Collecting samples without
"sloughed solids" may be appropriate to examine the clarity of the effluent, but are not
appropriate to evaluate actual effluent concentrations. Samples taken during sloughing periods,
which contain biomass, are more appropriate to obtain information on suspended solids
concentrations, which would give some indication if a solids loading problem is occurring. If
high solids are encountered on a regular basis, then close observation of the condition of the tile
field or other receiving soil system should be part of the system checks.
No particular design considerations are necessary relative to placement, as the unit makes very
little noise. Since approximately 80 percent of the Biofilter unit protrudes out of the ground
(four feet), some siting considerations based on this feature may be desired. The basic
components of the system appear durable and should perform well under typical home
wastewater conditions.
The Manual (Appendix A) provided by WBS is comprehensive and provides information for
installation, startup, operation, and servicing of the Biofilter® system. The Manual includes
information on the theory of biological treatment and descriptions of observations that can be
made to visually check the condition of the biomass. The visual color inspection and
assumptions guide in the maintenance checklist gives an indication of possible upset conditions.
It should be noted that the "determination" of color and deciding that all "brown is bad" is
probably stretching the science and the abilities of a maintenance person. However, providing
this detail helps highlight the importance of observing the condition of the biomass in the unit.
4.5 Quality Assurance/ Quality Control
The VTP included a QA/QC Plan (QAPP) with critical measurements identified and several
QA/QC objectives established. The verification test procedures and data collection followed the
QAPP, and summary results are reported in this section. The full laboratory QA/QC results and
supporting documentation are presented in Appendices D, E, and F.
4.5.1 Audits
Two audits of the MASSTC and Barnstable County Health Department Laboratory were
conducted by NSF during the verification test. These audits, in August 2001 and January 2002,
found that the field and laboratory procedures were generally being followed. Recommendations
for changes or improvements were made and the responsible organizations responded quickly to
these recommendations. The finding of these audits was that the overall approach being used in
the field and the laboratory were in accordance with the established QAPP.
The only finding that needed immediate attention during the first lab audit in August 2001 was
the lack of method blanks in the nitrite and nitrate tests at the proper frequency. The calibration
standards gave a very good linear relationship and the analyses were considered valid. Corrective
4-30
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action was accomplished immediately. All other findings were paper work related, such as
updating training records and SOPs. Recommendations were made to improve the detail placed
in the field logs, and to be sure, that calibrations were documented and field duplicate samples
collected as planned. The second audit in January 2002 found that recommendations had been
implemented and no new findings were identified for immediate corrective action. The field and
lab managers were reminded of activities that needed to be completed before the end of the test
in accordance with the Test Plan.
A third audit was conducted at the end of the verification test. This audit reviewed the records
and procedures that were used. A list of documents and data needed for the final report was
prepared and discussed with the field and laboratory managers.
Internal audits of the field and laboratory operations were also conducted at least quarterly by
BCDHE. These audits specifically reviewed procedures and records for the ETV project. Any
shortcomings found during these internal audits were corrected as the test continued.
4.5.2 Daily Flows
One of the critical data quality objectives was to dose the unit on a daily basis to within 10
percent of the design flow. For the Biofilter® system the design flow was 440 gpd. The QC
objective was to dose the unit at 440 gpd plus or minus 10 percent, based on a monthly average
of the daily flows. The dose volume were calibrated twice per week and if the volume changed
by more than ten percent the dosing pump run time was adjusted in the PLC. The objective was
met for all 13 months of the verification test period. The monthly averages were presented in
Table 4-4. The daily flows for all months are presented in spreadsheet format in Appendix F. The
field logs in Appendix G provide the twice per week calibration data that is summarized in the
spreadsheets.
4.5.3 Precision
Precision measurements were performed throughout the verification test by collection and
analysis of duplicate samples. Field duplicates were collected to monitor the overall precision of
the sample collection and laboratory analyses. There were three or four similar verification tests
running simultaneously at the MASSTC. Field duplicates were generally collected on each
sampling day, with the sample selected for replication rotating among the three or four
technologies. The results for the field duplicates are presented in a spreadsheet in Appendix D.
Summaries of the data are presented in Tables 4-13 through 4-15.
The precision for nitrogen compounds was generally excellent, particularly given the low levels
of ammonia, TKN, and nitrate in some of the effluent samples. A few sample results were
outside the target window of either 10 percent RPD (nitrite, nitrate) or 20 RPD percent (TKN,
NH3), but in most cases, the results were for samples that were very low in concentration. As an
example, one set of data for TKN showed replicate one as 0.9 mg/L and replicate two as 0.5
4-31
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mg/L with a detection limit of 0.5 mg/L. The calculated RPD for this sample is 57 percent. Even
though the relative percent difference (RPD) is high, the data is reasonable given the low
concentration found in the samples.
The test plan did not differentiate between laboratory precision and field precision. Typically,
field precision targets are wider than laboratory goals to account for sampling variation, in
addition to the laboratory variation. Also, the precision goals for nitrite and nitrate were set very
tight (10 percent RPD), which would appear to be tighter than required for acceptable
wastewater analysis and evaluation of these parameters. Using the 10 percent RPD criteria, 8 out
of 49 field duplicates for nitrate exceeded the target, and 7 out of 50 duplicates for nitrite
exceeded the window. TKN showed 10 out of 59 field duplicates exceeded the target cf 20
percent RPD. Ammonia results were similar with 6 out of 60 samples above the target of 20
percent RPD, with all exceedances for samples having a concentration of less than 1 mg/L.
Table 4-13. Duplicate Field Sample Summary - Nitrogen Compounds
TKN
Ammonia
(mg/L)
(mg/L)
Statistics
Rep 1
Rep 2
RPD
Rep 1
Rep2
RPD
Number
60
60
59
60
60
60
Average
14
15
13
8.9
00
00
11
Median
7.5
8.1
6.5
5.0
5.0
4.5
Maximum
49
51
135
29
28
133
Minimum
<0.5
<0.5
0.0
<0.2
<0.2
0
Std. Dev.
14
14
22
9.1
9.0
21
Nitrite
Nitrate
(mg/L)
(mg/L)
Statistics
Rep 1
Rep 2
RPD
Rep 1
Rep2
RPD
Number
50
50
46
50
50
49
Average
0.32
0.33
5.3
6.9
6.9
6.3
Median
0.30
0.30
2.0
6.2
6.1
4.3
Maximum
0.95
1.1
33
15
15
36
Minimum
<0.05
<0.05
0.0
<0.1
0.70
0.0
Std. Dev.
0.20
0.22
8.4
4.1
4.2
8.3
Number = Number of analyses used in the calculations
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Table 4-14. Duplicate Field Sample Summary - CBOD, BOD, Alkalinity, TSS
CBOD5
BOD5
(mg/L)
(mg/L)
Statistics
Rep 1
Rep 2
RPD
Rep 1
Rep2
RPD
Number
50
50
50
10
10
10
Average
10
10
20
220
210
10
Median
6.7
6.7
14
230
220
11
Maximum
60
54
110
280
270
23
Minimum
1.9
2.3
0.51
140
150
1.1
Std. Dev.
11
9.5
19
44
43
6.6
TSS
(mg/L)
Alkalinity
(mg/L as CaCC>3)
Statistics
Rep 1
Rep 2
RPD
Rep 1
Rep2
RPD
Number
60
60
59
60
60
60
Average
32
31
31
120
120
3.4
Median
7
9
12
110
100
1.8
Maximum
260
260
190
220
220
27
Minimum
1
<1
0
56
54
0
Std. Dev.
57
54
43
46
46
5.6
Number = Nurrber of analyses used in the calculations
Table 4-15. Duplicate Field Sample Summary - pH, Dissolved Oxygen
pH
(S.U.)
Dissolved Oxygen
(mg/L)
Statistics
Rep 1
Rep 2
RPD
Rep 1
Rep2
RPD
Number
60
55
55
12
12
12
Average
7.4
7.4
0.4
5.9
5.9
0
Median
7.4
7.5
0.1
5.8
5.8
0
Maximum
8.0
8.0
3.8
9.9
9.9
0
Minimum
6.6
6.8
0
2.5
2.5
0
Std. Dev.
1.0
0.3
0.6
2.2
2.2
0
Calculated using log scale
All replicates gave same value
Number = Number of analyses used in the calculations
The CBOD5 and TSS data tended to have poorer precision than the other analyses, because this
data is based on treated effluent samples that are below 10 mg/L. Comparison of average values
and median values shows that much of the TSS data is at low concentration. Both CBODs and
TSS have detection limits of 1 or 2 mg/L. TSS is generally reported to one significant figure at
levels below 10 mg/L. It is expected that precision will be poorer at the lower concentrations and
near the detection limit of the methods. Further, the influence of variability in sample collection
can be seen in this data as well. The laboratory precision data presented in Table 4-17 shows a
tighter precision for TSS (13 percent in lab versus 31 percent for field duplicates). The difficulty
of getting a well-mixed sample for low level suspended solids undoubtedly added to the lower
precision for the TSS test. Overall, the TSS results showed 26 out of 59 samples were outside the
target of 20 percent RPD and 18 out of 50 samples were outside the target for CBOD5. Only 2
4-33
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out of 16 CBOD5 samples exceeded the target when the concentration was above 10 mg/L.
While this data indicates that precision is lower at the lower concentrations, the overall data set
provides the needed information that showed the ability of the treatment unit to significantly
reduce TSS and CBOD5 in the wastewater. Laboratory procedures, calibrations, and data were
audited and found to be in accordance with the published methods and good laboratory practice.
The laboratories performed lab duplicates on a frequency of at least one per batch or 10 percent
of samples. The laboratory precision data is summarized in Tables 4-16 and 4-17. The various
nitrogen analyses showed excellent precision, as did the alkalinity results. Nitrite results showed
no samples (60 total) exceeded the very tight target of 10 percent RPD. Nitrate results showed 14
out 211 values exceeded the 10 percent RPD target, but only 1 result out 211 exceeded a 20
percent difference.
The CBOD5 and TSS precision was generally within the target objective of 20 percent RPD,
except when the concentrations were low. As discussed earlier, when effluent samples were
below 10 mg/L the calculated percent differences were higher, as would be expected. The
CBOD5 and BOD5 analyses used very similar procedures, and were performed together under the
same conditions in the laboratory. The BODs data showed much higher precision (average of 8
percent) than the CBOD5 (average 15 percent). This is primarily due to the higher concentrations
of BOD5 (influent wastewater samples). In summary, 18 out of 57 results exceeded the CBOD5
target of 20 percent RPD, but none of the samples over 10 mg/L exceeded the target (0 out of
17); BOD5 results showed 7 out of 64 results were above the target; and 8 out of 44 TSS samples
showed RPD above 20 percent. On-site audits and review of procedures and calibrations
indicated that good laboratory practice was being followed. There were no identified, systematic
errors that would account for the difference. The data for all analyses was judged acceptable and
useable for evaluating the treatment efficiency.
Table 4-16. Laboratory Precision Data - Nitrogen Compounds
Statistics
Relative Percent Difference (RPD)
TKN
Ammonia
Nitrite
Nitrate
Number
59
53
67
211
Average
7.6
3.1
2.7
3.1
Median
4.7
0
0.0
2.1
Maximum
55
36
18
25
Minimum
0.0
0
0.0
0.0
Std. Dev.
11
6.6
4.3
3.7
Number = Number of analyses used in the calculations
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Table 4-17. Laboratory Precision Data - CBOD5, BOD5, Alkalinity, TSS
CBOD5
BOD5
(mg/L)
(mg/L)
Statistics
Rep 1
Rep 2
RPD
Rep 1
Rep2
RPD
Number
57
57
57
64
64
64
Average
18
18
15
160
160
7.7
Median
5.9
6.7
7.6
170
170
4.4
Maximum
100
100
73
500
530
32
Minimum
<2.0
2.0
0
<2.0
<2.0
0
Std. Dev.
24
24
15
120
120
8.1
TSS
(mg/L)
Alkalinity
(mg/L as CaCC>3)
Statistics
Rep 1
Rep 2
RPD
Rep 1
Rep2
RPD
Number
44
44
44
48
48
48
Average
72
73
13
83
84
6.1
Median
52
54
5
80
80
1.8
Maximum
290
310
130
190
190
40
Minimum
1
4
0
2
2
0
Std. Dev.
73
72
24
58
59
12
Number = Number of analyses used in the calculations
4.5.4 Accuracy
Method accuracy was determined and monitored using a combination of matrix spikes and lab
control samples (known concentration in blank water) depending on the method. Recovery of the
spiked analytes was calculated and monitored during the verification test. Accuracy was in
control throughout the verification test. All recoveries for all spiked samples for alkalinity,
BOD5, nitrite, and nitrate were within the established windows. Only 1 result out of 51 spiked
samples was outside the recovery target for CBOD5. Tables 4-18 and 4-19 show a summary of
the recovery data. All quality control data is presented in Appendix D.
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Table 4-18. Accuracy Results - Nitrogen Analyses
TKN
Ammonia
(% Recovery)
(%
Recovery)
Statistics
Matrix
Lab Control
Matrix
Lab Control
Spike
Sample
Spike
Sample
Number
54
59
50
57
Average
95
100
99
107
Median
96
99
100
107
Maximum
137
114
112
120
Minimum
62
86
51
91
Std. Dev.
16
6.2
9.3
7.2
Nitrite
Nitrate
(% Recovery)
(%
Recovery)
Statistics
Matrix
Lab Control
Matrix
Lab Control
Spike
Sample
Spike
Sample
Number
50
54
24
119
Average
104
99
98
99
Median
104
99
97
98
Maximum
123
120
113
116
Minimum
80
82
85
81
Std. Dev.
10
9.7
8.4
8.0
Number = Number of analyses used in the calculations
Table 4-19. Accuracy Results - CBOD, BOD, Alkalinity
CBOD5
bod5
Alkalinity
(% Recovery)
(% Recovery)
(% Recovery
Statistics
Lab Control Sample
Lab Control Sample
Lab Control
Sample
Number
51
54
61
Average
100
101
100
Median
101
101
100
Maximum
106
109
113
Minimum
77
84
93
Std. Dev.
5
4
3
Number = Number of analyses used in the calculations
The balance used for TSS analysis was calibrated routinely with weights that were NIST
traceable. Calibration records were maintained by the laboratory and inspected during the on site
audits. The temperature of the drying oven was also monitored using a thermometer that was
calibrated with a NIST traceable thermometer. The pH meter was calibrated using a three-point
calibration curve with purchased buffer solutions of known pH. Field temperature measurements
were performed using a thermometer that was calibrated using a NIST traceable thermometer
provided to the field lab by the BCDHE laboratory. The dissolved oxygen meter was calibrated
daily using ambient air and temperature readings in accordance with the SOP. The noise meter
was calibrated prior to use and all readings were recorded in the field logbook. All of these
traceable calibrations were performed to ensure the accuracy of measurements.
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4.5.5 Representativeness
The field procedures, as documented in the MASSTC SOPs (Appendix C), were designed to
ensure that representative samples were collected of both influent and effluent wastewater. The
composite sampling equipment was calibrated on a routine basis to ensure that proper sample
volumes were collected to provide flow weighted sample composites. Field duplicate samples
and supervisor oversight provided assurance that procedures were being followed. As discussed
earlier, the challenge in sampling wastewater is obtaining representative TSS samples and
splitting the samples into laboratory sample containers. The field duplicates showed that there
was some variability in the duplicate samples. However, based on 60 sets of field duplicates, the
overall average TSS of the replicates was very close (32 and 31 mg/L). This data indicated that
while individual sample variability may occur, the long-term trend in the data was representative
of the concentrations in the wastewater.
The laboratories used standard analytical methods and written SOP's for each method to provide
a consistent approach to all analyses. Sample handling, storage, and analytical methodology
were reviewed during the on-site and internal audits to verify that standard procedures were
being followed. The use of standard methodology, supported by proper quality control
information and audits, ensured that the analytical data was representative of the actual
wastewater conditions.
4.5.6 Completeness
The VTP set a series of goals for completeness. During the startup and verification test, flow data
was collected for each day and the dosing pump flow rate was calibrated twice a week as
specified. The flow records are 100 percent complete. Electric meter records were maintained in
the field logbook. Electric meter readings were performed twice a week and summarized in a
spreadsheet. Only one electric meter reading was missed (the first reading at startup) during the
startup and verification test. Out of 195 readings, one was incomplete giving a completeness of
99 percent complete.
The goal set in the VTP for sample collection completeness for both the monthly samples and
stress test samples was 83 percent. All monthly samples were collected and all stress test samples
were collected in accordance with the VTP schedule. Therefore, sample collection was 100
percent complete.
A goal of 90 percent was set for the completeness of analytical results from the BCDHE
laboratory and GAI. All scheduled analyses for delivered samples were completed and found to
be acceptable, useable data. Completeness is 100 percent for the laboratory.
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5.1 Cited References
5.0 REFERENCES
(1) NSF International, Protocol for the Verification of Residential Wastewater Treatment
Technologies for Nutrient Reduction, November 2000, Ann Arbor, Michigan.
(2) EPA, Wastewater Technology Fact Sheet Trickling Filter Nitrification, September 2000,
Office of Water, Washington D.C., EPA 832-F-00-015
(3) EPA, Manual for Nitrogen Control, 1993, 625/R-93/010
(4) NSF International, Test Plan for The Massachusetts Alternative Septic System Test Center for
Verification Testing of AWT Biofilter Nutrient Reduction Technology, January 2001
(5) United States Environmental Protection Agency: Methods and Guidance for Analysis of
Water, EPA 821-C-99-008, 1999. Office of Water, Washington, DC.
(6) United States Environmental Protection Agency: Methods for Chemical Analysis of Water
and Wastes, Revised March 1983, EPA 600/4-79-020
(7) APHA, AWWA, and WEF: Standard Methods for the Examination of Water and
Wastewater, 19th Edition, 1998. Washington, DC.
5.2 Additional Background References
(8) United States Environmental Protection Agency: Environmental Technology Verification
Program - Quality and Management Plan for the Pilot Period (1995 - 2000), EPA/600/R-
98/064, 1998. Office of Research and Development, Cincinnati, Ohio.
(9) NSF International, Environmental Technology Verification - Source Water Protection
Technologies Pilot Quality Management Plan, 2000. Ann Arbor, Michigan.
(10)United States Environmental Protection Agency: EPA Guidance for Quality Assurance
Project Plans, EPA QA/G-5, EPA/600/R-98-018, 1998. Office of Research and
Development, Washington, DC
(11) United States Environmental Protection Agency, Guidance for the Data Quality Objectives
Process, EPA QA/G-4, EPA/600/R-96-055, 1996. Office of Research and Development,
Washington, DC.
(12)ANSI/ASQC: Specifications and Guidelines for Quality Systems for Environmental Data
Collection and Environmental Technology Programs (E4), 1994
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