Environmental Technology Verification Report Reduction of Nitrogen in Domestic Wastewater from Individual Residential Homes Bio-Microbics, Inc. RetroFAST 0.375 System


September 2003
03/08/WQPC- SWP

Environmental Technology
Verification Report

Reduction of Nitrogen in Domestic
Wastewater from Individual
Residential Homes

Bio-Microbics, Inc.

RetroFAST® 0.375 System

Prepared by

®

NSF International

Under a Cooperative Agreement with

SERA U.S. Environmental Protection Agency

ETVETVETV

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THE ENVIRONMENTAL TECHNOLOGY VERIFICATION

PROGRAM

SERA ElV <3

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:

RETROFAST® 0.375 SYSTEM

COMPANY:

BIO-MICROBICS

ADDRESS:

8450 COLE PARKWAY
SHAWNEE, KS 66227

PHONE: (913) 422-0707
FAX: (913)422 0808

WEB SITE:
EMAIL:

http: // www. biomicrobics. com
onsite@biomicrobics.com

NSF International (NSF) operates the Water Quality Protection Center (WQPC) under the
U.S. Environmental Protection Agency's (EPA) Environmental Technology Verification (ETV) Program.
The WQPC evaluated the performance of a submerged attached-growth biological treatment system for
nitrogen removal for residential applications. This verification statement provides a summary of the test
results for the Bio-Microbics, Inc. RetroFAST® 0.375 System (RetroFAST®). NovaTec Consultants, Inc.
(NovaTec) performed the verification testing.

EPA created the 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 accelerating the acceptance and use of improved and
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 RetroFAST® was conducted over a twelve-month period at the Mamquam
Wastewater Technology Test Facility (MWTTF) located at the Mamquam Wastewater Treatment Plant
(WWTP), which serves the District of Squamish, British Columbia, Canada. An eight-week startup period
preceded the verification test to provide time for the development of an acclimated biological growth in
the RetroFAST®. 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 RetroFAST® proved capable of removing nitrogen from the wastewater. The influent
total nitrogen (TN) mean concentration was 39 mg/L, with a median of 36 mg/L. The effluent TN (total
Kjeldahl nitrogen (TKN) plus nitrite/nitrate (N027N0"3)) mean concentration was 19 mg/L over the
verification period, with a median concentration of 18 mg/L. During the first two months of testing, an
apparent upset condition occurred. During investigation of the upset, Bio-Microbics determined that the
blower setting of 30 minutes on and 30 minutes off was incorrect. The blower was changed to continuous
operation and the verification test continued for eleven months. The mechanical components of the
RetroFAST® (blower, airlift, and optional alarm) operated properly throughout the test. No maintenance
or operational changes were required during the final eleven months of the verification test.

TECHNOLOGY DESCRIPTION

The following technology description is provided by the vendor and does not represent verified
information.

The RetroFAST® 0.375 System is a submerged attached-growth treatment system, which is inserted as a
retrofit device into the outlet side of new or existing septic tanks. The RetroFAST® has a rated capacity
of 375 gallons per day (gpd), and is designed to treat wastewater from a single-family home with four to
six persons. The only mechanical component is a remotely housed air blower, which provides air for
oxygen supply and mixing to the aerated chamber. The media used is PVC or polyethylene cross-flow
media, with a total installed packed volume of 12 cubic feet. A small control panel with an alarm
designed to activate if the blower fails is available as an option.

Wastewater enters the septic tank in the primary treatment zone, which can be a separate compartment
(the verification test used a two-compartment septic tank) or an area that extends from the inlet pipe to the
forward bulkhead of the insert. The quiescent condition in the primary zone allows the heavy solids in
the wastewater to settle to the bottom of the chamber, where they are gradually digested under anaerobic
conditions. The wastewater then flows into the aerobic zone (either the second compartment or the area
of the tank containing the RetroFAST® insert). The organic constituents in the wastewater serve as food
for the aerobic bacteria that are attached to the honeycomb media in the RetroFAST® unit and present in
the suspended solids (mixed liquor) in the liquid phase within the unit. An external blower supplies air to
a draft tube located in a central chamber in the submerged media. The draft tube acts as an airlift pump to
draw wastewater from below the media and distribute it over the media surface by a splash plate above
the water line. The draft tube induces a circulation of wastewater down through the media and provides
oxygen to the wastewater. Nitrified wastewater flows through the bottom of the central chamber into the
surrounding anoxic zone, where solids settle to the bottom of the second chamber. Denitrification occurs
in the anoxic zone in this chamber. The clarified effluent is discharged by gravity, flowing through an
opening (notch) that separates the discharge water from the aeration zone and exiting via a discharge pipe.

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VERIFICATION TESTING DESCRIPTION

Test Site

The MWTTF site is located at the wastewater treatment plant serving the District of Squamish, British
Columbia, Canada. Wastewater is supplied from a sanitary sewer collection system serving a catchment
consisting of primarily residential houses, with minor commercial sources. After passing through the
WWTP screens and grit-removal processes, wastewater is pumped through a 2.5-inch diameter manifold
pipeline to the test site, at a rate of approximately 53 gallons per minute (gpm) (3.4 liters per second
[L/s]). During dosing periods, wastewater is constantly circulated through the manifold pipeline to ensure
solid material contained in the wastewater does not settle. Excess flow in the manifold is discharged to
the headworks of the WWTP. Dosing at each test unit is regulated by a pneumatic gate valve that is
controlled by a programmable logic controller (PLC). The PLC enables operators to monitor the operating
status of the test facility and the individual test units, and to change any of the dosing parameters (e.g.,
dosage volume, frequency of dosage, duration of dosing period, etc.).

Methods and Procedures

The RetroFAST® was installed by the MWWTP operators with the assistance of Bio-Microbics staff on
June 6, 2001. The unit was installed in the second compartment of a two-compartment septic tank in
accordance with the installation instructions supplied by Bio-Microbics. On July 6, 2001, the septic tank
was filled with one-third wastewater and two-thirds potable water, and the dosing sequence began. An
eight-week startup period allowed the biological community to become established and the operating
conditions to be monitored. The standard dosing sequence was used for the entire startup period.

The system was monitored during the startup period, including visual observation of the system and
routine calibration of the dosing system. Several influent samples were collected and analyzed for pH,
alkalinity, temperature, five-day biochemical oxygen demand (BOD5), TKN, ammonia nitrogen (NH3-N),
N02", N03~, and total suspended solids (TSS). Effluent samples were analyzed for pH, alkalinity,
temperature, five-day carbonaceous biochemical oxygen demand (CBOD5), TKN, NH3-N, TSS, dissolved
oxygen (DO), N02", and NO/.

The thirteen-month verification test period incorporated 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.
Nitrogen reduction was monitored by measuring nitrogen species (TKN, NH3-N, N02", N03). Other
basic parameters (BOD5, CBOD5, pH, alkalinity, TSS, temperature) were monitored to provide
information on overall system 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 verification test was designed to load the RetroFAST® at design capacity (375 gpd ± 10%) for the
entire test, except during the low load and vacation stress tests. The RetroFAST® was dosed 100 times
per day with approximately 3.7 gallons of wastewater per dose. The unit received 35 doses in the
morning, 25 doses mid-day, and 40 doses in the evening. The dosing volume was controlled by the
length of time the pneumatic valve was open for each cycle. Dosing volumes were verified once per
week.

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 more intensely, with six to eight composite samples being collected during and after each
stress test period. Five consecutive days of sampling occurred in the last month of the verification test.
All composite samples were collected using automatic samplers located at the dosing manifold pump

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location (influent sample) and at the discharge of the unit. Grab samples at each sample location were
collected on each sampling day to monitor the system pH, DO, and temperature.

All samples were cooled during sample collection; preserved, if appropriate; and transported to the
laboratory. All analyses were completed in accordance with EPA-approved methods or Standard
Methods. An established quality assurance/quality control (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 RetroFAST® began on July 6, 2001, when the septic tank was filled and the wastewater
dosing started. Flow was set at 375 gpd based on delivering 80 doses per day with a target of 4.7 gallons
per dose. Samples of the influent and effluent were collected during the startup period, which continued
until September 4, 2001. The dosing sequence was adjusted in September to delivery 100 doses per day
with a delivery of 3.7 gallons per dose. Verification testing began September 5, 2001, and continued until
October 25, 2002. Sampling and equipment problems in October and November 2001 resulted in the
verification test being extended to fourteen months in order to obtain a full set of valid data. During the
verification test, 60 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 installation instructions were easy to follow, and
installation proceeded without difficulty. No changes were made to the unit during the startup period, and
no special maintenance was required.

The RetroFAST® was removing CBOD5 and TSS within the first three weeks of operation. At the end of
the eight-week startup, effluent CBOD5 was 8 mg/L and TSS was 6 mg/L. The effluent TN concentration
was 12 mg/L at the end of the startup period, ranging from 6 to 12 mg/L in the final four weeks of startup.
Influent TN concentration ranged from 30 to 37 mg/L during this time. Both the nitrification and
denitrification processes appeared established at the end of the startup period, as indicated by the
difference between influent and effluent TN. The blower was set to operate 30 minutes on and 30
minutes off during this period.

Verification Test Results

The daily dosing schedule was adjusted slightly at the beginning of the verification test. The dose
sequence was set for 100 doses of 3.7 gallons per dose to be applied every day, except during the low load
(May to June 2002) and vacation stress (September 2002) periods. Volume per dose and total daily
volume varied only slightly during the verification test. The daily volume, averaged on a monthly basis,
ranged from 366 to 380 gpd, within the range allowed in the protocol for the 375 gpd design capacity.

The sampling program emphasized sampling during and after the major stress periods. This resulted in a
large number of samples being clustered during five periods, with the remaining monthly samples spread
over the remaining months. Both mean and median results were calculated, because comparing median
values to mean values can help evaluate the impacts of the stress periods. The RetroFAST® results
showed median concentrations for NH3-N that were somewhat lower than the mean concentrations due to
reduced nitrification efficiency in the December 2001 to January 2002 and July to August 2002 periods,
which impacted the mean concentration.

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The TSS and BOD5/CBOD5 results for the verification test, including all stress test periods, are shown in
Table 1. The influent wastewater had a mean BOD5 of 150 mg/L and a median BOD5 of 150 mg/L. The
TSS in the influent had a mean concentration of 180 mg/L and a median concentration of 170 mg/L. The
RetroFAST® effluent showed a mean CBOD5 of 12 mg/L with a median CBOD5 of 12 mg/L. The mean
TSS in the effluent was 28 mg/L and the median TSS was 24 mg/L.

Table 1. BOD5/CBOD5 and TSS Data Summary

bod5

CBODs

TSS

Influent

Effluent

Percent

Influent

Effluent

Percent

(mg/L)

Removal

(mg/L)

Removal

Mean

150

180

Median

150

170

Maximum

210

440

170

Minimum

110

Std. Dev.

5.9

4.4

Note: Data in Table 1 are based on 60 samples.

The nitrogen results for the verification test, including all stress test periods, are shown in Table 2. The
influent wastewater had a mean TKN concentration of 39 mg/L, with a median value of 36 mg/L, and a
mean NH3-N concentration of 28 mg/L, with a median of 28 mg/L. The mean TN concentration in the
influent was 39 mg/L (median of 36 mg/L). The RetroFAST® effluent had a mean TKN concentration of
11 mg/L and a median concentration of 6.2 mg/L. The mean ammonia concentration in the effluent was
5.9 mg/L and the median value was 3.4 mg/L. The nitrite concentration in the effluent was low, averaging
0.46 mg/L. The mean effluent nitrate concentration was 8.0 mg/L with a median of 9.1 mg/L. Total
nitrogen was determined by adding the daily concentrations of the TKN (organic plus ammonia nitrogen),
nitrite, and nitrate. The mean TN in the RetroFAST® effluent was 19 mg/L (median 18 mg/L) for the
verification period. The RetroFAST® showed a mean TN reduction of 51%, with a median removal of
50%.

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 InfluentEffluent Effluent Effluent Effluent

Mean

5.9

8.0

0.46

12.8

Median

6.2

3.4

9.1

0.46

14.5

Maximum

1.2

20.2

Minimum

1.7

0.15

6.4

0.06

0.04

4.90

Std. Dev.

9.0

3.9

7.0

9.0

7.5

5.0

0.31

4.75

Note: The data in Table 2 are based on 60 samples, except for nitrite and nitrate, which are based
on 58 samples.

Verification Test Discussion

During the first two months of the verification test, September and October 2001, the nitrification and
denitrification processes, which had been established during startup, were upset, and only small amounts
of ammonia or TN were removed by the RetroFAST® system. TSS levels in the effluent were variable
ranging from 8 to 59 mg/L. The ETV test team investigated possible causes for the upset condition
despite no apparent changes in the influent wastewater quality. On November 14 during a system check
by Bio-Microbics, it was determined that the blower setting of 30 minutes on and 30 minutes off was not

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correct for the system. On November 14, Bio-Microbics changed the blower setting to operate
continuously, after which the RetroFAST® began to recover. Due to some difficulties at the test site and
sampling problems during the first stress test in November, it was agreed that the verification stress test
sequence would be restarted in December, and that the November data would be reported but excluded
from the verification test data summaries.

The NH3-N concentration in the effluent began to decrease at the end of November and nitrate
concentrations increased. TN removal approached 50%. The washday stress test was performed from
December 24 to December 28, 2001. The NH3-N and TKN began to rise at the end of the stress test, and
nitrate decreased. By the end of the post-stress test monitoring on January 3, 2002, the data showed no
removal of TN by the system. The washday stress test appears to have upset the system. It should be
noted that the temperature of the wastewater was also decreasing during this time, and there was a one-
day spike in influent TSS near the end of the monitoring period. These factors may have contributed to
the system performance.

During the next six weeks, the RetroFAST® system re-established the nitrifying population. Effluent TN
concentration dropped to 13 mg/L and ammonia nitrogen to 0.3 mg/L. The working parent stress test was
performed from February 25 through March 1, 2002. The NH3-N concentration in the effluent increased
during the stress period (4.8 mg/L), but was lower at the end of the stress period and during the post-stress
monitoring. Nitrate levels, however, remained in the 13 to 15 mg/L range. TN removal was above 50%
for most days, with concentrations ranging from 19 to 22 mg/L in the post-stress monitoring period. The
working parent stress test did not appear to have a major impact on the nitrification process. During the
next two months, the data show that more than 80% of the ammonia was being removed. However, nitrate
levels increased to 17 to 18 mg/L, indicating the denitrification process was not able to convert all of the
additional nitrate to nitrogen gas. The DO level in the effluent was in the 9.5 to 11 mg/L during this time.

The low load stress test began on May 6 and continued until May 26, 2002. Both the nitrification and
denitrification processes appeared to improve during and after this stress test. Ammonia concentrations
dropped below 1 mg/L, nitrate levels decreased to the 9 to 11 mg/L range, and TN nitrogen removal was
46 to 61% after the first ten days of the stress test. The lower daily volume of wastewater (50% of the
rated capacity) being processed through the unit may be a factor in the improved performance of the unit.

During the June and July test period, which included the power failure test on July 22, the effluent TN
concentration ranged from 11 to 17 mg/L. Ammonia concentrations increased each day during the post-
stress test monitoring and reached a maximum of 12 mg/L on August 1. At the same time, the nitrate
concentrations decreased, although the actual removal cf nitrate by the system (assuming all ammonia
removed is converted to nitrate) remained in the 14 to 19 mg/L range. It does appear that the power
failure stress test had an impact on the system, which might be expected because the nitrification system
is dependent on oxygen supplied by the blower. Late in the post-stress test monitoring period, ammonia
removal performance began to deteriorate and did not appear to recover until September.

The vacation stress test started on September 23 and ended on October 2, 2002. During this period, there
was no influent flow to the system. Following the resumption of flow on October 2, ammonia
concentrations in the effluent were generally less than 1 mg/L, similar to the levels found during the low
load test. Nitrate levels increased, but denitrification continued to remove 14 to 20 mg/L of nitrate from
the system. The vacation stress test did not appear to have a negative impact on the system.

The system performance remained consistent for the duration of the verification test. The TKN and NH3-
N effluent concentrations were low and similar to the data from the period after the low load stress test.
The nitrate levels remained in the 10 to 13 mg/L range, and the TN concentration from 15 to 18 mg/L,
representing 49 to 61% removal.

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The RetroFAST® system showed variable results during the verification test, with TN removal varying
from zero to 86% removal. There were at least two apparent upset periods, one at the start of the
verification test (possibly caused by the blower setting) and another during the washday stress test. A
smaller upset in the nitrification process may have occurred at the end of the power failure post-stress-
monitoring period in July 2002. During the last six months of the verification test, the system appeared
more stable and performance was more consistent. During these last six months of operation, the TN
concentration in the effluent had a mean concentration of 15 mg/L (range of 6 to 21 mg/L).

Operation and Maintenance Results

Noise levels associated with blower system and airlift were measured twice 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, at 90° intervals in four directions. The noise levels ranged from 58 to 64 decibels.

Qualitative odor observations based on odor strength (intensity) and type (attribute) were made six times
during the verification test. 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 five of the six observation periods. On the final observation, the odor
was logged as a barely discernable musty odor.

A dedicated electric meter, serving the RetroFAST®, was used to monitor electrical use for the period of
continuous blower operation. The average electrical use was 2.1 kilowatts (kW) per day. This usage rate
appears low for a one-fourth horsepower blower operating continuously, but was consistent during the
verification test and checked with a second meter. The RetroFAST® did not require or use any chemical
addition during normal operation.

During the test, the system experienced no mechanical problems. The only change made to the system
was to alter the blower operation from an on/off cycle to continuous operation on November 14, 2001.
No maintenance or cleaning was performed during the verification test.

The treatment unit appeared to be of durable design and proved to be durable during the test. The piping
and construction materials used in the system meet the application needs. Although blower life is
difficult to estimate, the equipment used operated continuously for eleven months with no downtime.

Quality Assurance/Quality Control

During testing, NSF completed a QA/QC audit of the MWTTF site and CanTest Laboratories Ltd.
(CanTest), the analytical laboratory. This audit included: (a) a technical systems audit to assure the
testing was in compliance with the test plan, (b) a performance evaluation audit to assure that the
measurement systems employed by MWTTF and CanTest were adequate to produce reliable data, and (c)
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. EPA QA personnel also conducted a quality systems audit of NSF's
QA Management Program.

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Original signed by
Lee A. Mulkey

09/30/03

Original signed by
Gordon E. Bellen

Lee A. Mulkey Date

Acting Director

National Risk Management Research Laboratory

Office of Research and Development

United States Environmental Protection Agency

Gordon E. Bellen
Vice President
Research
NSF International

10/02/03

Date

NOTICE: Verifications are based on an evaluation of technology performance under specific,
predetermined criteria and the appropriate quality assurance procedures. EPA and NSF make no
expressed or implied warranties as to the performance of the technology and do not certify that a
technology will always operate as verified. The end user is solely responsible for complying with
any and all applicable federal, state, and local requirements. Mention of corporate names, trade
names, or commercial products does not constitute endorsement or recommendation for use of
specific products. This report in no way constitutes an NSF Certification of the specific product
mentioned herein.

Availability of Supporting Documents

Copies of the ETV Protocol for Verification of Residential Wastewater Treatment
Technologies for Nutrient Reduction, dated November 2000, the Verification Statement,
and the Verification Report are available from the following sources:

1. ETV Water Quality Protection Center Manager (order hard copy)

NSF International

P.O. Box 130140

Ann Arbor, Michigan 48113-0140

2. NSF web site: http://www.nsf.org/etv (electronic copy)

3. EPA web site: http://www.epa.gov/etv (electronic copy)

(NOTE: Appendices are not included in the Verification Report. Appendices are
available from NSF upon request.)

EPA's Office of Wastewater Management has published a number of documents to assist
purchasers, community planners and regulators in the proper selection, operation and
management of onsite wastewater treatment systems. Two relevant documents and their
sources are:

1. Handbook for Management of Onsite and Clustered Decentralized Wastewater
Treatment Systems http://www.epa.gov/owm/onsite

2. Onsite Wastewater Treatment Systems Manual
http: // www. epa/gov/owm/ mtb/decent/toolbox, htm

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Environmental Technology Verification Report

Reduction of Nitrogen in Domestic Wastewater
from Individual Residential Homes

Bio-Microbics, Inc.
RetroFAST® 0.375 System

Prepared for

NSF International
Ann Arbor, MI 48105

Prepared by

Scherger Associates
In cooperation with
NovaTec Consultants, Inc.

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

September 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, 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 U.S. Environmental Protection Agency (EPA) is charged by Congress with protecting the
Nation's land, air, and water resources. Under a mandate of national environmental laws, the
Agency strives to formulate and implement actions leading to a compatible balance between
human activities and the ability of natural systems to support and nurture life. To meet this
mandate, EPA's research program is providing data and technical support for solving
environmental problems today and building a science knowledge base necessary to manage our
ecological resources wisely, understand how pollutants affect our health, and prevent or reduce
environmental risks in the future.

The National Risk Management Research Laboratory (NRMRL) is the Agency's center for
investigation of technological and management approaches for preventing and reducing risks
from pollution that threaten human health and the environment. The focus of the Laboratory's
research program is on methods and their cost-effectiveness for prevention and control of
pollution to air, land, water, and subsurface resources; protection of water quality in public water
systems; remediation of contaminated sites, sediments and ground water; prevention and control
of indoor air pollution; and restoration of ecosystems. NRMRL collaborates with both public
and private sector partners to foster technologies that reduce the cost of compliance and to
anticipate emerging problems. NRMRL's research provides solutions to environmental problems
by: developing and promoting technologies that protect and improve the environment; advancing
scientific and engineering information to support regulatory and policy decisions; and providing
the technical support and information transfer to ensure implementation of environmental
regulations and strategies at the national, state, and community levels.

This publication has been produced as part of the Laboratory's strategic long-term research plan.
It is published and made available by EPA's Office of Research and Development to assist the
user community and to link researchers with their clients.

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Contents

Verification Statement	VS-i

Notice	ii

Foreword	iii

Contents	iv

Figures	vi

Tables	vi

Acronyms and Abbreviations	vii

Acknowledgments	ix

Chapter 1 Introduction	1

1.1	ETV Purpose and Program Operation	1

1.2	Testing Participants and Responsibilities	1

1.2.1	NSF International - Verification Organization (VO)	2

1.2.2	U.S. Environmental Protection Agency	2

1.2.3	Testing Organization	3

1.2.4	Technol ogy Vendor	4

1.2.5	ETV Test Site	5

1.2.6	Technology Panel	6

1.3	Background - Nutrient Reduction	6

1.3.1	Biological Nitrification	6

1.3.2	Biological Denitrification	8

Chapter 2 Technology Description and Operating Processes	10

2.1	General Technology Description	10

2.2	Equipment Specifications	11

2.3	Operation and Maintenance	15

2.4	Vendor Claims	15

Chapter 3 Methods and Test Procedures	16

3.1	Verification Test Plan and Procedures	16

3.2	MWTTF Test Site Description	16

3.3	Installation and Startup Procedures	17

3.3.1	Introduction	17

3.3.2	Objectives	17

3.3.3	Installation and Startup Procedure	18

3.4	Verification Testing - Procedures	18

3.4.1	Introduction	18

3.4.2	Objectives	19

3.4.3	System Operation- Flow Patterns and Loading Rates	19

3.4.3.1	Influent Flow Pattern	19

3.4.3.2	Stress Testing Procedures	19

3.4.3.3	Sampling Locations, Approach, and Frequency	20

3.4.3.4	Residuals Monitoring and Sampling	24

3.4.4	Analytical Testing and Record Keeping	24

3.4.5	Operation and Maintenance Performance	25

3.4.5.1	Electric Use	25

3.4.5.2	Chemical Use	25

iv

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3.4.5.3	Noise	25

3.4.5.4	Odors	25

3.4.5.5	Mechanical Components	26

3.4.5.6	Electrical/Instrumentation Components	26

Chapter 4 Results and Discussion	27

4.1	Introduction	27

4.2	Startup Test Period	27

4.2.1	Startup Flow Conditions	27

4.2.2	Startup Analytical Results	28

4.2.3	Startup Operating Conditions	29

4.3	Verification Test	29

4.3.1	Verification Test - Flow Conditions	29

4.3.2	Verification Test Restart	30

4.3.3	BOD5/CBOD5 and TSS Results and Discussion	31

4.3.4	Nitrogen Reduction Performance	37

4.3.4.1	Results	37

4.3.4.2	Discussion	46

4.3.5	Residuals Results	47

4.4	Operations and Maintenance	49

4.4.1	Electric Use	49

4.4.2	Chemical Use	50

4.4.3	Noise	50

4.4.4	Odor Observations	50

4.4.5	Operation and Maintenance Observations	51

4.5	Quality Assurance/ Quality Control	53

4.5.1	Audits	53

4.5.2	Daily Flows	53

4.5.3	Precision	53

4.5.3.1	Laboratory Duplicates	53

4.5.3.2	Field Duplicates	54

4.5.4	Accuracy	56

4.5.5	Representativeness	58

4.5.6	Completeness	58

Appendices	59

A Bio-Microbics - Homeowners Manual	59

B Verification Test Plan	59

C Lab Data and QA/QC Data	59

D Field Operations and Lab Logbooks	59

E Spreadsheets with calculation and data summary	59

F Laboratory Raw Data	59

Glossary	60

References	62

Bibliography	62

v

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Figures

Figure 2-1. RetroFAST® 0.375 System general layout	12

Figure 2-2. RetroFAST® 0.375 System side and top view	13

Figure 2-3. RetroFAST® 0.375 System components	14

Figure 4-1. RetroFAST® 0.375 System BOD5/CBOD5 results	33

Figure 4-2. RetroFAST® 0.375 System TSS results	34

Figure 4-3. RetroFAST® 0.375 System TKN results	38

Figure 4-4. RetroFAST® 0.375 System NH3-N results	39

Figure 4-5. RetroFAST® 0.375 System TN results	40

Figure 4-6. RetroFAST® 0.375 System NO2 and NO3 effluent concentrations	41

Tables

Table 2-1. RetroFAST® 0.375 System Specifications	11

Table 3-1. Historical MWTTF Wastewater Data	17

Table 3-2. Sampling Matrix	22

Table 3-3. Sampling Schedule for RetroFAST® 0.375 System	23

Table 3-4. Summary of Analytical Methods, Precision, and Accuracy Requirements	24

Table 4-1. Flov^Volume Data during the Startup Period	28

Table 4-2. Influent Wastewater Quality - Startup Period	29

Table 4-3. RetroFAST® 0.375 System Effluent Quality - Startup Period	29

Table 4-4. RetroFAST® 0.375 System Influent Volume Summary	30

Table 4-5. RetroFAST® 0.375 System BOD5/CBOD5 and TSS Results	35

Table 4-6. RetroFAST® 0.375 System Influent and Effluent Nitrogen Data	42

Table 4-7. RetroFAST® 0.375 System Alkalinity, pH, and DO Results	44

Table 4-8. Solids Depth Measurement—First Compartment	48

Table 4-9. TSS and VSS Results for the RetroFAST® 0.375 System Solids Samples	49

Table 4-10. Summary of RetroFAST® 0.375 System Electrical Usage	50

Table 4-11. RetroFAST® 0.375 System Noise Measurements	50

Table 4-12. Odor Observations	51

Table 4-13. Laboratory Precision Limits	54

Table 4-14. Duplicate Field Sample Summary - Nitrogen Compounds	55

Table 4-15. Duplicate Field Sample Summary - BOD5/CBOD5, TSS, Alkalinity	55

Table 4-16. Laboratory Control Limits for Accuracy	57

vi

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Acronyms and Abbreviations

ANSI

American National Standards Institute

Bio-Microbics

Bio-Microbics, Inc.

BOD5

Biochemical Oxygen Demand (five day)

°C

Degrees Celsius (temperature)

CaC03

Calcium Carbonate

CanTest

CanTest Laboratories, Ltd.

CBOD5

Carbonaceous Biochemical Oxygen Demand (five day)

Cuft

Cubic Feet

DO

Dissolved Oxygen

DQI

Data quality indicators

DQO

Data quality objectives

EPA

(U.S.) Environmental Protection Agency

ETV

Environmental Technology Verification

ft

Feet

gal

U.S. Gallons

gpm

(U.S.) Gallons Per Minute

hp

Horsepower

in

Inches

kW

Kilowatt

kW/d

Kilowatts per Day

MWTTF

Mamquam Wastewater Technology Test Facility

mg/L

Milligrams per liter

mL

Milliliters

NIST

National Institute of Standards and Technology

NH3-N

Ammonia Nitrogen

N02

Nitrite Nitrogen

N03

Nitrate Nitrogen

NovaTec

NovaTec Consultants, Inc.

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

PVC

Polyvinyl Chloride

QA

Quality Assurance

QAPP

Quality Assurance Project Plan

QC

Quality Control

QMP

Quality management plan

RetroFAST®

RetroFAST® 0.375 System

RPD

Relative Percent Difference

SAG

Stakeholders Advisory Group

SCADA

Control Microsystems Micro 16 SCADA System

SOP

Standard Operating Procedure

SWP

Source Water Protection Area (Water Quality Protection Center)

vii

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s.u.

Standard Units for pH

TKN

Total Kjeldahl Nitrogen

TN

Total Nitrogen

TO

Testing Organization

TS

Total Solids

TSS

Total Suspended Solids

VFA

Volatile fatty acids

vo

Verification Organization

VR

Verification Report

vss

Volatile Suspended Solids

VTP

Verification Test Plan

WQPC

Water Quality Protection Center

WWTP

Mamquam Wastewater Treatment Plant

viii

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Acknowledgments

The Testing Organization (TO), NovaTec Consultants, Inc., 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. Dr. Troy Vassos was the Project Manager
for the Verification Test. Ms. Lynn Mallett was the Project Coordinator.

NovaTec Consultants, Inc.

224 West 8th Avenue
Vancouver, BC, Canada V5Y 1N5
(604) 873-9262

Contact: Dr. Troy Vassos, Project Manager
Email: tvassos@novatec.ca

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:

CanTest Laboratories, Ltd.

4606 Canada Way
Burnaby, BC, Canada V5G 1K5
(604) 734-7276
Contact: Mr. E. Jensen
Email: ejensen@cantest.com

The Manufacturer of the equipment was:

Bio-Microbics, Inc.

8450 Cole Parkway

Shawnee, KS 66227

(913)422-0707

Contact: Mr. Brian Jones

Email: bjones@biomicrobics.com

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.

IX

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Chapter 1
Introduction

1.1 ETV Purpose and Program Operation

EPA has created the ETV Program to facilitate the deployment of innovative or improved
environmental technologies through performance verification and dissemination of information.
The ETV Program's goal is to further environmental protection by 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 (TOs);
stakeholders groups that consist of buyers, vendor organizations, consulting engineers, and
regulators; 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 adequate
quality are generated and that the results are defensible.

In cooperation with EPA, NSF 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 RetroFAST® 0.375 System for the reduction of total
Kjeldahl nitrogen (TKN), ammonia nitrogen (NH3-N), nitrite nitrogen (NO2), and nitrate nitrogen
(NO3) present in residential wastewater. Bio-Microbics, Inc. (Bio-Microbics) sells the
RetroFAST® 0.375 System as a retrofit system for wastewater treatment or as an enhancement
for full-sized, soil-based systems at single-family homes. Other models of the system are
available for larger residences, commercial businesses, and similar applications, but this
evaluation does not address those models. The unit is designed to work in conjunction with a
septic tank system to provide nitrogen reduction in addition to the removal of organics and solids
present in these wastewaters. The RetroFAST® 0.375 System is based on attached submerged
growth (fixed film) biological treatment. This report provides the verification test results for the
RetroFAST® 0.375 System, in accordance with the Protocol for the Verification for Residential
Wastewater Treatment Technologies for Nutrient Reduction, November 2000 [1],

1.2 Testing Participants and Responsibilities

The ETV testing of the RetroFAST® 0.375 System was a cooperative effort between the
following participants:

. NSF

• NovaTec Consultants, Inc. (NovaTec)

• Mamquam Wastewater Technology Test Facility (MWTTF)

• CanTest Laboratories, Ltd.

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• Scherger Associates

• Bio-Microbics
. EPA

1.2.1 NSF International - Verification Organization (VO)

The WQPC of the ETV is administered through a cooperative agreement between EPA and NSF.
NSF is the verification partner organization for the WQPC and the SWP area within the center.
NSF administers the center and contracts with the Testing Organization (TO) to develop and
implement the Verification Test Plan (VTP).

NSF's responsibilities as the VO 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 TO and, subsequently, qualify
the companies making up the TO;

• 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 quality assurance/quality control (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, MI 48105
(734)769-8010

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, NRMRL, provides administrative,
technical, and QA guidance and oversight on all ETV WQPC activities. EPA reviews and

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approves each phase of the verification project. 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 TO for the verification testing was the NovaTec Consultants, Inc. (NovaTec). The project
manager, Dr. Troy Vassos, was responsible for the overall development of the VTP, oversight
and coordination of all testing activities, and compilation and submission all of the test
information for development of this final report.

Mr. Dale Scherger of Scherger Associates was contracted by NSF to work with NovaTec to
prepare the Verification Report (VR) and Verification Statement.

CanTest Laboratories, Ltd. 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 VTP;

• Conduct verification testing, according to the VTP;

• Install, operate, and maintain the RetroFAST® 0.375 System in accordance with the
Vendor's operation and maintenance (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 as
needed;

• Resolve any quality concerns that might be encountered and report all findings to the
verification organization;

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•	Manage, evaluate, interpret, and report data generated by verification testing;

•	Evaluate and report the performance of the technology; and,

•	If necessary, document changes in plans for testing and analysis, and notify the VO of
any and all such changes before changes are executed.

The key personnel and contacts for the TO are:

Dr. Troy Vassos, Project Manager

(604) 873-9262 email: tvassos@novatec.ca

Ms. Lynn Mallett, Project Coordinator

(604) 873-9262 email: lmallett@novatec.ca

NovaTec Consultants, Inc.

224 West 8th Avenue
Vancouver, BC, Canada V5Y 1N5

The laboratory that conducted the analytical work for this study was:
Mr. E. Jensen

(604)734-7276 email: ejensen@cantest.com

CanTest Laboratories, Ltd.

4606 Canada Way

Burnaby, BC, Canada V5G 1K5

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

(734)213-8150 email: Daleres@aol.com

Scherger Associates
3017 Rumsey Drive
Ann Arbor, MI 48105

1.2.4 Technology Vendor

The nitrogen reduction technology evaluated was the RetroFAST® 0.375 System manufactured
by Bio-Microbics, Inc. Bio-Microbics was responsible for supplying all equipment needed for

4

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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
VTP;

•	Select the test site;

•	Provide complete, field-ready equipment and the O&M manual(s) typically provided
with the technology (including instructions on installation, startup, operation, and
maintenance) for verification testing;

•	Provide any existing relevant performance data for the technology;

•	Provide assistance to the TO 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,

•	Provide funding for verification testing.

The key contact for Bio-Microbics is:

Mr. Brian Jones

(913) 422-0707 email: bjones@biomicrobics.com

Bio-Microbics, Inc.

8450 Cole Parkway
Shawnee, KS 66227

1.2.5 ETV Test Site

The Mamquam Wastewater Technology Test Facility (MWTTF, the host site for the nitrogen
reduction verification test, is located at the Mamquam Wastewater Treatment Plant (WWTP),
which serves the District of Squamish, British Columbia. The site is designed to test on-site
wastewater treatment systems and related technologies. MWTTF provides the location to install
the technology and all of the infrastructure support requirements to collect domestic wastewater,
and pump the wastewater to the system, as well as operational and maintenance support for the
test. Key items provided by the test site are:

•	Logistical support and reasonable access to the equipment and facilities for sample
collection and equipment maintenance;

•	Primarily domestic wastewater that is representative of domestic wastewater relative to
key parameters such as five-day biochemical oxygen demand (BODs,. total suspended
solids (TSS), total nitrogen (TN), and phosphorus;

•	A location for sampling 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;

5

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•	Sufficient flow of wastewater to accomplish the required controlled dosing pattern;

•	Daily operation and observation of the test unit, including maintaining a daily logbook
and collecting flow, electrical use, and related information;

•	Setup of sampling equipment and collection of samples per the established schedule;

•	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 does not occur.

1.2.6 Technology Panel

Representatives from the Technology Panel assisted the VO in reviewing and commenting on the
VTP.

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 that reduce oxygen-demanding materials, suspended solids, and pathogenic
organisms. Reduction of nutrients, principally phosphorus and nitrogen, has been practiced since
the 1960s at centralized wastewater treatment plants. Nutrient reduction is needed primarily to
protect the quality of ground- or surface water for drinking (drinking-water standards for NO2
and NO3 have been established) and to reduce the potential for eutrophication in nutrient-
sensitive surface waters and the consequent loss in ecological, commercial, recreational, and
aesthetic uses.

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
eutrophication 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
RetroFAST® 0.375 System process is based on fixed film submerged growth biological
treatment. According to Bio-Microbics, aerobic and anoxic conditions are maintained in
separate sections of the RetroFAST® when inserted into the septic tank.

1.3.1 Biological Nitrification

Nitrification is a process carried out by bacterial populations (5Vitrosomonas 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:

6

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1) Ammonium is oxidized to nitrite (NO2") by Nitrosomonas bacteria.

2 NH4+ + 3 02 =2 N02" + 4rf + 2 H20

2) The nitrite is converted to nitrate (NO3") by Nitrobacter bacteria.

2 NO2 " +O2 = 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 (DO) concentration.

Organic loading: Organic loadings affect the efficiency of the nitrification process. 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 do at high BOD5
concentrations. As a result, the nitrifiers can be overgrown by heterotrophic bacteria, which can
cause the nitrification process to cease. In order for nitrification to take place, the organic
loadings must be low enough to provide balance between the heterotrophic and nitrifying
bacteria. In a submerged growth filter such as the RetroFAST® unit, the bacteria are attached to
the filter and present as suspended growth biomass within the unit. The filter media provides a
surface area for nitrifier attachment that may enhance the nitrification process as compared to
suspended growth only systems.

Hydraulic loading: In a submerged growth filter system, wastewater normally flows through a
highly specific area media that is submerged in the mixed liquor of the treatment system. The
total hydraulic flow to the submerged media can be controlled by adjusting the recirculation rate
of the wastewater flow through the media. Both hydraulic and organic loadings are important
parameters that must be considered. Recirculation benefits nitrifying reactors by reducing the
influent BOD5 concentration, which makes the nitrifiers more competitive. Control of the food
to microorganism ratio is important to maximize the nitrification process.

pH: The nitrification process produces acid, which lowers the pH and can reduce 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 calcium carbonate [CaC03]) are destroyed per pound of ammonia oxidized to
nitrate.

Dissolved Oxygen (DO): The concentration of DO 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-growth 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, the maximum growth rate is not needed for effective nitrification if there

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is adequate contact time in the system. As a result there is a broad range of DO values at which
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 oxygen equivalent (electron acceptor)
for bacteria, and the nitrate is reduced to nitrogen gas. Denitrifying bacteria are facultative
organisms that can use either DO or nitrate (NO3) 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:

6NO3" + 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.

DO. The level of DO has a direct impact on the denitrifying organisms. As DO increases, the
denitrification rate decreases. DO concentrations below 0.3 to 0.5 mg/L in the anoxic zone are
typically needed to achieve efficient denitrification.

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 to 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 during the nitrification process. Approximately 3.6
pounds of alkalinity is produced for each pound of nitrate nitrogen removed.

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Additional information on various nitrogen control strategies can be found in the Manual for
Nitrogen Control, USEPA, 1993, 625/R-93/010 [2],

9

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Chapter 2

Technology Description and Operating Processes

2.1 General Technology Description

The Bio-Microbics RetroFAST® 0.375 System (RetroFAST®) is a submerged attached-growth
(fixed film) treatment system, which is marketed by Bio-Microbics as a retrofit device into the
outlet side of new or existing septic tanks. The RetroFAST® has a rated capacity of 375 gallons
per day (gpd), and is designed to treat wastewater from a single-family home with four to six
persons.

The primary effluent flows into the aerobic zone (either the second compartment or the area of
the tank containing the RetroFAST® insert). The organic constituents serve as food for the
aerobic bacteria, which are attached to the honeycomb media in the RetroFAST® and are present
in the suspended solids (mixed liquor) in the liquid phase with the unit. An external blower
supplies air to a draft tube located in a central chamber in the submerged media. The draft tube
acts as an airlift pump to draw wastewater from below the media and distribute it over the
surface by a splash plate above the water line. The draft tube induces a circulation of wastewater
down through the media and provides oxygen to wastewater. The aerobic bacteria consume
organic material and convert ammonia to nitrite (NO2) and then to NO3. Nitrified wastewater
flows through the bottom of the central chamber into the surrounding (un-aerated) anoxic zone,
where solids settle to the bottom of the second chamber. Denitrification occurs in the anoxic
zone in this chamber. The clarified effluent flows by gravity through a small opening in the wall
that separates the aeration zone from the discharge zone, and exits the unit via a discharge pipe to
the discharge location. For the ETV test, the treated effluent entered a sump, and the effluent
was pumped back to the Mamquam wastewater treatment plant.

The septic tank used for the ETV testing program was a two-chamber 1,350 gallon tank. The
first chamber volume was 880 gallons, and the second chamber was 470 gallons, separated by a
concrete wall. Figure 2-1 shows a cut-away view of the RetroFAST® as installed in a septic tank.
Wastewater from the first chamber flows to the second chamber through a pipe in the divider
wall that has a tee on the end so that floating materials are retained in the first chamber. The
treated effluent exits the RetroFAST® through a small opening that separates the mixed aerated
wastewater from the effluent flowing to the three-inch exit pipe (See Figure 2-1 and 2-2). Flow
is by gravity, and the exit flow rate is based on the influent flow rate. The only mechanical

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component is the remote air blower, which provides compressed air to the aerated chamber for
oxygen supply and mixing. . The RetroFAST* utilizes a 1/4 hp regenerative blower producing 21
cubic feet per minute (cfm). Polyvinyl chloride (PVC) or polyethylene cross-flow media is
used, with a total installed packed volume of 12 cubic feet (cu ft). The blower is contained in a
remote housing. A small control panel with an alarm designed to activate if the blower fails is
available as an option. Figure 2-2 show side and top views of the RetroFAST® insert and the
blower assembly.

2.2 Equipment Specifications

The specifications for the RetroFAST® 0.375 System are summarized in Table 2-1. All of the
piping used in the system is Schedule 40 PVC pipe to be supplied by the contractor completing
the installation. Components of the system are shown in Figure 2-3.

Table 2-1. RetroFAST® 0.375 System Specifications

Item	Quantity

RetroFAST® 0.375 Unit	1

Self contained with:

Airlift system

PVC cross flow media (12 cu ft)

RetroFAST® blower system	1

Vihp regenerative blower
Blower housing
Control panel and blower alarm	1

(Optional feature)

Operations and Maintenance Manual	1

11

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(1)	Influent line from home - gravity feed to first compartment

(2)	First compartment for solids separation and settling

(3)	Remote blower to deliver air (oxygen) to the RetroFast Insert

(4)	RetroFast ' unit - aerobic process with media for attached growth; air lift
circulates water from bottom of compartment two to top of RetroFast®

(5)	Effluent line to tile field or other receiving location, flow by gravity

Figure 2-1. RetroFAST® 0.375 System general layout.

12

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NOTES

1,	BLOWER MUST BE WITHIN 100 FEET C30,5m>
~F FAST® UNIT. FOR DISTANCES GREATER
THAN 100 FEET — CONSULT FACTORY,
BLOWER MUST BE LOCATED ABOVE
NORMAL FLOOD LEVELS.

2.	VENT TO BE LOCATED ABOVE FINISH GRADE
OR HIGHER TO AVOID INFILTRATION. SECURE
6' VENT GRATE CNDS 6-034 W/9.1 SQ. IN.
OPEN SURFACE AREA OR EQUIVALENT) WITH
STAINLESS STEEL SCREWS.

ORi

RUN VENT TO DESIRED LOCATION AND
COVER OPENING WITH PROVIDED 4' VENT
GRATE. SECURE WITH PROVIDED 3/4'
SCREWS. VENT MUST NOT ALLOW EXCESS
MOISTURE BUILDUP.

5. ALL APPURTENANCES TO FAST® UNIT  MUST
CONFORM TO ALL COUNTRY, STATE,

PROVINCE AND LOCAL CODES,

4,	BLOWER CONTROL SYSTEM BY BIO-
MICROBICS, INC.

5,	COPYRIGHT  2001, BIO-MICROBICS, INC.

6,	FAST© MODULE MUST BE SECURED BY
BOLTING THROUGH THE STRAPS, THEN THE
LID IS BOLTED TO THE TANK. NOTEi
ANCHOR BOLTS NOT PROVIDED. NOTE. STRAP
DIMESIDNS' 37' L x 9' W, 2 STRAPS TOTAL,

7,	EFFLUENT HOLE WILL ACCEPT A 3' SCH
40 PVC PIPE WHICH CAN THEN BE
INSERTED INTO THE EXISTING 4' DISCHARGE
PIPE IN THE SEPTIC TANK,

VIEW A-A

Date 7-01-02

Bloj MICROBICS r

RetroFAST0.375 L

BMI~

Figure 2-2. RetroFAST® 0.375 System side and top view

13

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KetroFAST* SYSTEM

COMPONENTS

Tank Lid with 18"

min. manhole

RetroFAST<

Liner

Effluent Gasket

Effluent Chamber

Figure 2-3. RetroFAST® 0.375 System components.

14

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2.3	Operation and Maintenance

Bio-Microbics provides a Homeowners Manual (Manual) with important information about the
RetroFAST® 0.375 System, including specific sizing and installation instructions, a basic
overview of the treatment process, and a troubleshooting table covering common treatment and
system problems. A copy of this information is presented in Appendix A. Maintenance is
focused primarily on the blower system. Periodic cleaning of the screens on the blower housing
and the openings on the vent system is recommended. Annual inspection and cleaning of the air
intake filter is suggested to avoid blower damage. According to Bio-Microbics, no maintenance
is required for any underground components in the RetroFAST® insert.

Each unit includes a two-year warranty for parts. Bio-Microbics does not specifically
recommend that a service contract be arranged to provide periodic maintenance for their units,
but does provide example service contracts that can be used by their suppliers. Bio-Microbics
recommends that their suppliers maintain a spare parts inventory including two blowers, two
control panels, and several air filters.

2.4	Vendor Claims

Bio-Microbics claims the RetroFAST® 0.375 System is designed to retrofit existing septic tanks
or upgrade full-sized soil-based systems to reduce nitrogen, BOD5, and TSS present in
residential wastewater. No specific levels of treatment are indicated.

15

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Chapter 3
Methods and Test Procedures

3.1 Verification Test Plan and Procedures

The VTP, Test Plan for the Bio-Microbics RetroFAST® 0.375 Under the US Environmental
Protection Agency Environmental Technology Verification Program at the Mamquam
Wastewater Technology Test [3], August 2001, prepared and approved for the verification of the
Bio-Microbics, Inc., RetroFAST® 0.375 System, is included in Appendix B. The VTP was
prepared in accordance with the SWP protocol, Protocol for the Verification of Residential
Wastewater Treatment Technologies for Nutrient Reduction [1], November 2000. The VTP
details the procedures and analytical methods to be used to perform the verification test. The
VTP included tasks designed to verify the nitrogen reduction capability of the RetroFAST®
0.375 System and obtain information on the operation and maintenance requirements of the
RetroFAST® 0.375 System. The VTP covered two distinct phases of fieldwork: startup of the
unit and a one-year verification test that included normal dosing and stress conditions. The
verification test was completed between September 2001 and October 2002.

This section describes each of the testing elements performed during technology verification,
including sample collection methods, analytical protocols, equipment installation, and equipment
operation. QA/QC procedures and data management approach are discussed in detail in the
VTP.

3.2 MWTTF Test Site Description

MWTTF is located at the Mamquam WWTP, which serves the District of Squamish, British
Columbia. Domestic wastewater is supplied from a sanitary sewer collection system serving a
catchment consisting primarily of residential houses, with minor contributions from commercial
sources.

Screened raw (influent) wastewater is pumped through a 2.5-inch diameter manifold pipeline to
each test site, at a rate of approximately 53 gpm (3.4 L/s). During dosing periods, wastewater is
constantly circulated through the manifold pipeline to ensure the influent wastewater being dosed
to the test units is "fresh," and that solid material contained in the wastewater has not settled out.
Once the wastewater has passed through the manifold pipeline, it is discharged to the headworks
of the Mamquam WWTP. The pressure in the manifold system is regulated downstream of the
pneumatic g^te so that a constant pressure is maintained on the line to provide a steady flow rate
through the pneumatic gate when it is open.

Dosing at each of the test sites is regulated by a pneumatic gate valve located at each of the
testing sites, which is controlled by a Control Microsystems Microl6 SCADA system (SCADA).
The SCADA system is monitored by a National Instruments LookOut interface, which displays
and logs the status of all test system components including pumps, pneumatic valves, samplers,
and analogue sensors. This SCADA system enables operators to monitor the operating status of
the test facility and the individual test units, and to change any of the dosing parameters (e.g.,
dosage volume, frequency of dosage, duration of dosing period, etc.).

-------
Dosing rates are verified by volumetric calibration checks (i.e., measuring the volume per dose),
which are performed weekly at each test site. Daily dosage volumes are calculated by
multiplying the dosage rate by the number of dosage events in a 24-hour period. The computer
control program determines the number of dosage events by dividing the daily dose for each test
unit by the calibrated dosage volume. The calculated daily dosage volume is verified by
monitoring of the daily volume pumped from the individual test unit treated effluent sumps (i.e.,
multiplying the calibrated sump-pump pumping rate by the total pumping time per day).

MWTTF maintains a small laboratory at the site to monitor basic wastewater treatment
parameters. Temperature, DO, pH, specific conductance, and volumetric measurements were
performed at the site during the RetroFAST® 0.375 test.

Influent wastewater quality has been monitored as part of normal WWTP operations, and is
within the requirements established in the Protocol fcr raw wastewater quality. These data are
presented in Table 3-1. Influent wastewater monitoring was part of the startup and verification
testing, and will be described later in this section. Results of all influent monitoring during the
verification test are presented in Chapter 4.

Table 3-1. Historical MWTTF Wastewater Data

Parameter Average
(mg/L)

BOD5 180

TSS 160

Total Nitrogen 40

NH3-N 29

Alkalinity 170

pH 7.4

3.3 Installation and Startup Pro cedures

3.3.1 Introduction

The system delivered by Bio-Microbics consisted of a complete RetroFAST® 0.375 System
(septic tank insert, blower assembly with housing, and control panel). This system was installed
by the MWTTF staff with the assistance of Bio-Microbics personnel on June 6, 2001. The
installation instructions provided by Bio-Microbics are presented in Appendix A.

3.3.2 Objectives

The objectives of the installation and startup phase of the VTP were to:

• Install the RetroFAST® 0.375 System in accordance with the instructions;

• Startup and test the RetroFAST® 0.375 System to ensure all processes were operating
properly;

-------
• Make any modifications needed to achieve operation; and

• Record and document all installation and startup conditions prior to beginning the
verification test.

3.3.3 Installation and Startup Procedure

The VTP and Protocol allow for an eight-week startup period, during which the biological
community was established and operating conditions were adjusted, if needed, for site
conditions. Following the installation, the septic tank with the RetroFAST® inserted in the
second compartment was filled with water, and each component of the system was checked for
proper operation. This installation represented a retrofit configuration with the larger primary
settling zone in the first compartment of a two-compartment septic tank. In a new system, a two-
compartment tank would be installed with the smaller chamber as the primary settling zone. The
blower system and control/alarm panel (an installed option) were checked and found to be
operating properly.

Startup of the RetroFAST® began on July 6, 2001. The septic tank was filled with 1/3
wastewater and 2/3 tap water, and the dosing sequence was started with a target of 4.76 gallons
of wastewater per dose to meet the targeted total daily flow of 375 gpd. The dosing sequence
followed the Protocol, as described in Section 3.4.3.1. The blower system was set to operate for
30 minutes on and 30 minutes off. In November 2001, Bio-Microbics determined that this
setting was not correct and adjusted the blower system to run continuously.

The system was monitored during the startup period (July 6 through September 5, 2001) by
visual observation of the system, routine calibration of the dosing system, and the collection of
influent and effluent samples several times over the eight-week startup period. Influent samples
were analyzed for some or all of the following parameters: pH, alkalinity, temperature, BOD5,
five-day carbonaceous biochemical oxygen demand (CBOD5), total Kjeldahl nitrogen (TKN),
NH3-N, and TSS analyses. The effluent was also analyzed for pH, alkalinity, temperature,
CBOD5, TKN, NH3-N, TSS, DO, NO2, and NO3. The same procedures for sample collection,
analytical methods, and monitoring were used during startup and the one-year verification
period, as described in Section 3.4.3.3.

3.4 Verification Testing - Procedures
3.4.1 Introduction

The verification test procedures were designed to verify nitrogen reduction by the RetroFAST®
0.375 System. 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 RetroFAST® 0.375 System. 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 (TN, TKN, NH3-N, NO2, NO3) removal the RetroFAST® 0.375
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 by-products 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.

3.4.3.1 Influent Flow Pattern

The influent flow dosed to RetroFAST® was controlled by the SCADA system. The doses were
set to provide doses of equal volume (target - 3.8 gallons per dose) in accordance with the
following schedule:

• 6 am-9 am approximately 35% of the total daily flow

• 11 am - 2 pm approximately 25% of the total daily flow

• 5 pm - 8 pm approximately 40% of the total daily flow

The initial total daily flow to the RetroFAST® was targeted to be 375 gpd. The QC requirement
for the dosing volume was 100 ± 10% of the target flow (375 gpd) based on a 30 day average,
with the exception of periods of stress testing. After each weekly calibration test (described in
Section 3.2), the measured volume was compared to this target rate. If the volume was more
than 10%) above or below the target, the SCADA was adjusted to reset the volume per dose back
to the target volume. The QC requirement for the dosing volume was 100 ± 10% of the target
flow (375 gpd) based on a thirty day average, with the exception of periods of stress testing. All
calibration tests were recorded in the field logbook. Flow information for each day of operation
was entered into a spreadsheet that showed the volume per dose, the total daily volume, and the
deviation from the target volume.

3.4.3.2 Stress Testing Procedures

During the verification test, one stress test was performed following every two months of
operation at the normal design loading. Five stress scenarios were run during the evaluation
period to test the RetroFAST® response to differing load conditions and a power/equipment
failure.

Stress testing included the following simulations:

• Washday stress

-------
• Working parent stress

• Low load stress

• Power/equipment failure stress

• Vacation stress

Washday stress simulation consisted of three washdays in a five-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 dosing
periods per day, the hydraulic loading included three wash loads consisting of three wash cycles
and six rinse cycles with a flow of 36 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 and non-chlorine bleach were added to each wash load at the manufacturer's
recommended amount.

The working parent stress simulation consisted of five consecutive days when the RetroFAST®
was subjected to a flow pattern where approximately 40% of the total daily flow was dosed
between 6 a.m. and 9 a.m., and approximately 60% of the total daily flow was dosed between 5
p.m. and 8 p.m. This simulation also included one wash load of one wash cycle and two 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 tested the unit at 50% of the target flow (188 gpd) loading for a
period of 21 days. Approximately 35% of the total daily flow was dosed between 6 a.m. and 11
a.m., approximately 25% of the flow was dosed between 11 a.m. and 4 p.m., and approximately
40% of the flow was dosed between 5 p.m. and 10 p.m.

The power/equipment failure stress simulation consisted of a standard daily flow pattern until 8
p.m. on the day the test was initiated. Power to the system was turned off at 9 p.m., and the flow
pattern was discontinued for 48 hours. After this 48-hour period, power was restored and the
system was dosed with approximately 60% of the total daily flow over a three- hour period,
which included one wash load of one wash cycle and two rinse cycles.

The vacation stress simulation consisted of a flow pattern where, on the day that the stress is
initiated, approximately 35% of the total daily flow was dosed between 6 a.m. and 9 a.m. and
approximately 25% of the total daily flow was received between 11 a.m. and 2 p.m. The flow
pattern was discontinued for eight 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% of
the total daily flow, which included three wash loads of three wash cycles and six rinse cycles.

3.4.3.3 Sampling Locations, Approach, and Frequency
3.4.3.3.1. Influent Sampling Location

Influent wastewater was sampled from the same place as the influent pump feeding the test
facility's manifold distribution pipe, which is located in a trench used to transfer wastewater
from the WWTP screens and grit removal process to the aerated bioreactors. Composite sample
and grab samples were collected at this location.

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3.4.3.3.2. RetroFAST® 0.3 75 System Effluent Sampling Location

The RetroFAST® effluent sample was collected from the end of the three-inch discharge pipe
that conveyed treated wastewater to the effluent sump. During installation and setup of the Bio-
Microbics unit, a sampling point consisting of a tee-cross with a "J" pipe of sufficient size to
retain sample volume for both grab and automated samples was installed on the discharge end of
the test unit. The piping was large enough to retain approximately one liter of fluid and be
readily flushed and replenished by the normal flow of treated effluent. The sump was accessible
so that the "J" pipe could be cleaned of attached and settled solids on a regular basis prior to
sampling dates. The sampling location in the discharge pipe was installed for the verification
test only, and would not be present in a typical residential installation. Consequently, cleaning of
the discharge pipe or "J" pipe would not be required in a normal system.

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 to measure pH
and temperature. The grab samples were collected by dipping a sample collection bottle into the
flow. The sample bottles were labeled with the sampling location, time, and date. All pH and
temperature measurements were performed at the on-site laboratory immediately after sample
collection. DO was measured in the effluent as the treated water flowed into the effluent sump.

Composite samples were collected using automated samplers at each sample collection point that
were programmed to draw equal volumes of sample from the influent and effluent streams.
Given that the volume of flow for each dose was constant, equal volume sub-samples result a
flow proportional composite sample. The influent sampler activation was timed to coincide with
the midpoint of the dosing cycle (i.e., if the dose time is 12 seconds, the sampler is triggered to
collect a sample at the 6-second mark). The effluent sampler timing was set to correspond to the
passage of a dose through the RetroFAST® discharge line. This time was calibrated by
determining the delay between the time flow entered the system and the time effluent began to
flow from the system. The effluent sampler was then set to start after this delay period. The
sample volumes collected by the automatic samplers were calibrated and verified by recording
the total volume of sample collected for each sampling day.

Table 3-2 shows a summary of the sampling matrix for the verification test.

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Table 3-2. Sampling Matrix

Sample Location

Parameter

Sample
Type

Influent

Effluent

Testing
Location

BOD5
CBODs

Composite
Composite

Laboratory
Laboratory

Suspended Solids

Composite

Laboratory

Grab

Test Site

Temperature (°C)

Grab

Test Site

Alkalinity (as CaCCb)

Composite

Laboratory

Grab

Test Site

TKN (as N)

Composite

Laboratory

nh3-n

Composite

Laboratory

Total NO3 (as N)

Composite

Laboratory

Total NO2 (as N)

Composite

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 on a monthly basis under design flow
conditions and more frequent sampling during the special stress test periods.

Normal Monthly Frequency

Samples of the influent and effluent were collected at least once per month for test period
(September 2001 - October 2002).

Stress Test Frequency

Samples were collected on the day each stress simulation was initiated and when approximately
50% of each stress sequence was completed. For the vacation and power/equipment failure
stresses, there was no midpoint sampling. Beginning 24 hours after the completion of washday,
working parent, low load, and vacation stress scenarios, samples were collected for six
consecutive days. Beginning 48 hours after the completion of the power/equipment failure
stress, samples were collected for five consecutive days.

Final Week

Samples were also collected for five consecutive days at the end of the yearlong evaluation
period.

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Table 3-3. Sampling Schedule for RetroFAST® 0.375 System

Month/Day

Sampling Event

July 23, 25, and August 1, 2001

Startup - 3 sampling events (CBOD5 and TSS)

August 8, 17, 22, 29, and September 5, 2001

Startup - 5 sampling events (all parameters)

September 10 and 30, 2001

Monthly sample - 2 samples

October 10, 26, and 29, 2001

Monthly sample - 3 samples

December 14, 2001

Monthly sample - 1 sample

December 24, 26, 29-31, 2001 and

Washday stress - 8 samples

January 1-3, 2002

Test started on December 24, 2001

January 30, 2002

Monthly sample - 1 sample

February 18, 2002

Monthly sample - 1 sample

February 25, 27, and March 2-7, 2002

Working parent stress - 8 samples



Test started on February 25, 2002

April 3 and 29, 2002

Monthly sample - 2 samples

May 6, 16, 27-31, and June 1-3, 2002

Low load stress - 10 samples



Test started on May 6, 2002

June 27, 2002

Monthly sample - 1 sample

July 19, 2002

Monthly sample - 1 sample

July 22, 27-31, and August 1, 2002

Power/equipment failure stress - 7 samples



Test started on July 22, 2002

August 28, 2002

Monthly sample - 1 sample

September 16, 2002

Monthly sample - 1 sample

September 23, 24, and October 3-8, 2002

Vacation stress - 8 samples



Test started on September 23, 2002

October 21-25, 2002

Final week sampling - 5 samples

3.4.3.3.5. Sample Handling and Transport

Samples were collected by automatic samplers into 2.5 gallon Nalgene containers, which were
wrapped in a Cryopak ice blanket 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 NHj-N
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).

The samples were packed in coolers with frozen ice packs provided by the laboratory to maintain
a temperature of 4 °C. Samples were transported to CanTest by courier or NovaTec personnel.
Travel time from MWTTF to CanTest was approximately 75 minutes.

23

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3.4.3.4 Residuals Monitoring and Sampling

Sludge depth in the tank was measured once at the end of the verification test. A coring sludge
measurement tool called a Sludge-Judge was used to estimate the depth of sludge/solids in the
first and second chamber of the 1,300 gallon septic tank. Depth of the solids deposits was
recorded in the Field Log.

Samples of the residuals/solids retained in each compartment of the tank were recovered using
the Sludge-Judge. The solids/residue portion of the sample from the Sludge-Judge, excluding
the liquid phase in the top portion of the sample, was emptied into a clean container, and the
sample analyzed for total solids (TS), TSS, and volatile suspended solids (VSS). An additional
sample of the first chamber was collected after the contents were vigorously mixed using a large
pump.

3.4.4 Analytical Testing and Record Keeping

Table 3-2 presented the parameter list, and Table 3-3 presented the sampling schedule. The
methods used for each constituent are shown in Table 3-4. Temperature, DO, and pH were
measured on-site. All other analyses were performed by CanTest.

Table 3-4. Summary of Analytical Methods, Precision, and Accuracy Requirements

Parameter

Facility

Acceptance
Criteria
Duplicates (%)

Acceptance

Criteria
Spikes (%)

Analytical Method

On-site

N/A

SM #4500 B

Temperature (°C)

On-site

N/A

SM #2550

On-site

N/A

SM #4500

Suspended Solids

CanTest

N/A

SM #2540 D

bod5/ cbod5

CanTest

N/A

SM #5210 B

Alkalinity

CanTest

85-115

SM #2320

Total NO2 (as N)

CanTest

86-112

EPA 353.3

Total NO3 (as N)

CanTest

90-110

EPA 353.3

TKN (as N)

CanTest

66-124

EPA 351.4

NH3-N (as N)

CanTest

80-120

EPA 350.1

Industry standard procedures were used for all sample analysis, as described in EPA Methods [4] [5], or Standard
Methods [6]

A Quality Assurance Project Plan (QAPP), developed as part of the VTP, provided QC
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, and so forth. Additional details are proved in
the VTP (Appendix B). A laboratory audit was 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.

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The results of all analyses from the off-site laboratory were reported to the TO by hard-copy
laboratory reports. The off-site laboratory also provided QA/QC data for the data sets. These
data and the laboratory reports are included in Appendix C. The on-site laboratory maintained a
laboratory logbook to record the results of all analyses performed at the site. A copy of the on-
site laboratory logbook is presented in Appendix D.

The data received from the laboratory were summarized in a spreadsheet by NovaTec personnel.
The data were checked against the original laboratory reports by the site staff, and checked by
NSF to ensure the data were accurately entered. The spreadsheets are included in Appendix E.

3.4.5 Operation and Maintenance Performance

The verification test evaluated both quantitative and qualitative performance of the RetroFAST®.
A field log noted all observations made during the startup of the unit and throughout the
verification test. Observations regarding the condition of the system, operation, or any problems
that required resolution were recorded in the log by the field personnel. Copies of the field logs
are presented in Appendix D.

Observation and measurement of operating parameters included evaluation of electric use,
chemical use, noise, odor, mechanical components, electrical/instrumentation components, and
by-product volumes and characteristics.

3.4.5.1 Electric Use

Electric use was monitored by a dedicated electric meter serving the RetroFAST®. The meter
reading was recorded daily and recorded in the field log.

3.4.5.2 Chemical Use

For this ETV testing, the RetroFAST® did not use any process chemicals to achieve treatment.

3.4.5.3 Noise

Noise levels associated with mechanical equipment were measured twice during the verification
test. Measurements were taken 1 meter (3 feet) from the source(s) at 1.5 meters above the
ground, at 90° intervals in four directions. The meter was calibrated prior to use.

3.4.5.4 Odors

The Mamquam WTTF operations personnel made periodic qualitative odor observations during
the verification test. The observations included odor strength (intensity) and type (attribute).
Intensity was noted as non-detectable, barely detectable, moderate, or strong. Observations were
made during periods of low wind velocity (<10 knots) while standing upright at a distance of 1
meter (3 feet) from the treatment unit, at 90° intervals in four directions. All observations were
made by the same Mamquam WTTF personnel, to the extent possible.

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3.4.5.5	Mechanical Components

Performance and reliability of the mechanical components, such as blowers, were observed and
documented in the Field Log during the test period. These observations recorded 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, as were any electrical equipment
failures, replacements, and the existence and use of duplicate or standby equipment.

26

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Chapter 4
Results and Discussion

4.1 Introduction

This chapter presents the results of the verification test for the RetroFAST® 0.375 System,
including the data for influent and effluent samples, a discussion of the results, and observations
on the operation and maintenance of the unit during startup and normal operation. Summaries of
the results are presented here. Complete copies of all spreadsheets with individual daily, weekly,
or monthly results are presented in Appendix E.

4.2 Startup Test Period

The startup period provided time for the RetroFAST® to develop a biological growth and
acclimate to the site-specific wastewater, and to be adjusted, if needed, to optimize performance
at the site. These first eight weeks of operation also allowed site personnel to become familiar
with the RetroFAST® operation and maintenance requirements. Samples were collected and
analyzed for CBOD5 and TSS during the first three weeks of startup, and for all test parameters
during the last five weeks of the startup period.

4.2.1 Startup Flow Conditions

The flow conditions for the RetroFAST® were established at the target capacity of 375 gpd in
accordance with the VTP. The SCADA was set to deliver approximately 4.7 gallons per dose.
Doses were delivered between 6 a.m. and 9 a.m. (35% of total), between 11 a.m. and 2 p.m.
(25% of total volume), and between 5 p.m. and 8 p.m. (40% of total). The volume of wastewater
dosed to the unit during the startup was generally within ± 10% of the targeted volume (338 to
412 gpd). A raw feed pump failure and an electrical problem at the test facility were addressed
during startup. These issues were resolved, and only four days were affected by these
maintenance issues at MWTTP. The influent dose problems were test facility issues, and not
related to the RetroFAST® unit. Table 4-1 shows a summary of the flow volumes during the
startup. The daily flow records appear in Appendix E.

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Table 4-1. Flov^Volume Data during the Startup Period

Date

Average

Average Daily Volume

(2001)

Gallons/dose

(Gallons)

July 5-17

4.7

371

July 18-31

4.8

348(1)

August 1-8

4.9

29i (2)

August 9-22

4.6

347

August 23-29

4.5

376

August 29 - September 4

4.5

378

(1) One day low volume of 181 gallons due to MWTTP pump failure; average without low
volume day was 360 gpd

(2) Three days of lower volums due to electrical problems at MWTTP
average without three low volume days was 355 gpd

4.2.2 Startup Analytical Results

The results of the influent and effluent monitoring during the startup period are shown in
Tables 4-2 and 4-3. After one month of operation, the data (August 1 and 8) show that the
RetroFAST® was removing more than 90% of the CBOD5 and TSS. The RetroFAST® was also
establishing the nitrification and denitrification processes, removing TN (37 mg/L in the influent,
15 mg/L in the effluent). Observations and additional sampling to determine the condition of the
unit continued for the next four weeks. No adjustments were made to the system.

At the end of the eight weeks allotted for the startup, the biological system was established. The
CBOD5 and TSS were <10 mg/L, and the unit was removing nitrogen from the wastewater (TN
removal of 68%). These data show that nitrification was established in the unit, although the last
sample in the startup period (September 5) showed an increase in NH3-N in the effluent
compared the previous two weeks. Denitrification was also occurring as shown by the NO3,
NO2, and the TN concentrations in the effluent. The alkalinity data also indicate establishment
of the nitrification and denitrification processes. Alkalinity in the effluent was lower than in the
influent, as the nitrification and denitrification processes, when operating together, result in a
drop in alkalinity. Theoretically, the nitrification process consumes 7.1 mg of alkalinity per 1
mg of NH3-N converted to NO3. The denitrification process produces alkalinity at the rate of 3.6
mg of alkalinity per mg of NO3 reduced to nitrogen. The net effect is a reduction of alkalinity in
the effluent wastewater.

-------
Table 4-2. Influent Wastewater Quality - Startup Period



bod5

CBODs

TSS

Alkalinity

PH

NHj-N

TKN

TN

Influent

Date

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(S.U.)

(mg/L)

(mg/L)

(mg/L)

Temp. (°C)

07/23/01

N/A

200

310

N/A

7.4

N/A

N/A

N/A

15.5

07/25/01

N/A

95

72

170

7.4

N/A

N/A

N/A

15.2

08/01/01

N/A

150

100

200

7.4

N/A

N/A

N/A

14.7

08/08/01

N/A

160

95

200

6.9

31

32

32

17.2

08/17/01

N/A

190

190

160

7.2

21

34

34

19.3

08/22/01

N/A

160

110

120

6.6

23

30

30

17.8

08/29/01

100

120

420

150

6.8

25

37

37

18.5

09/05/01

110

110

340

150

6.6

23

37

37

17.2

N/A - not analyzed

Table 4-3. RetroFAST® 0.375 System Effluent Quality - Startup Period















no2/









CBOD5

TSS

Alkalinity

PH

NH-N

TKN

no3

TN

DO

Discharge

Date

(mg/L)

(mg/L)

(mg/L)

(S.U.)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

(mg/L)

Temp (°C)

07/23/01

N/A

N/A

N/A

7.4

16

21

0.5

22

N/A

19.4

07/25/01

17

6

160

7.4

N/A

N/A

N/A

N/A

N/A

20.6

08/01/01

2

27

160

7.4

N/A

N/A

N/A

N/A

N/A

18.4

08/08/01

7

9

130

7.2

12

13

1.8

15

4.3

18.3

08/17/01

15

4

77

6.9

0.5

2.4

7.9

10

3.8

20.0

08/22/01

14

5

81

6.9

1.5

3.0

3.0

6.0

4.4

18.8

08/29/01

12

6

96

6.9

5.4

7.7

1.0

8.7

3.2

18.5

09/05/01

8

6

100

7.0

10

10

1.5

12

4.0

18.3

N/A - not analyzed

4.2.3 Startup Operating Conditions

The RetroFAST® was started with the blower set to operate thirty minutes on and thirty minutes
off. No changes were made to the unit during the startup period. Observations indicated that
biological growth was being established, and the visual effluent quality was acceptable.

4.3 Verification Test

In accordance with the startup period set forth in the VTP and the Protocol, the verification test
started officially on September 5, 2001. A last startup sample was collected on September 5. All
results for the remainder of the verification test were considered part of the verification test
period. The summary data presented for the verification results do not include data from the
startup period.

4.3.1 Verification Test - Flow Conditions

The standard dosing sequence was performed every day from September 5, 2001 through
October 25, 2002, except during the stress test periods. Table 4-4 shows the average monthly

29

-------
volumes for the verification period. As these data show, the actual wastewater volume dosed to
the RetroFAST® was very close to the design capacity and targeted volume of 375 gpd for the
entire verification test. All monthly averages meet the requirement of being within ± 10% of the
target. Daily flow volumes are presented in Appendix E.

Table 4-4. RetroFAST® 0.375 System Influent Volume Summary

Average Monthly

Month-Year

Gallons/dose

Gallons/day

Sep-01

4.13

366

Oct-01

3.83

380

Nov-01

3.84

372

Dec-01

3.71

376

Jan-02

3.67

373

Feb-02

3.67

372

Mar-02

3.66

372

Apr-02

3.82

378

May-02

3.72

375(1)

Jun-02

3.70

376

Jul-02

3.79

367(2)

Aug-02

3.95

374

Sep-02

3.99

379(3)

Oct-02

3.83

372(3)

Mean

3.81

374

Mean

3.81

373

Max

4.13

380

Min

3.66

366

Std Dev

0.14

4.08

(1) May - Low load test run; average flow data does not include the low flow days. Only normal

flow days are included. During the low load test, flow was set at 50% of normal flow. Actual
average flow during the low load test (May 6 to May 26) was 188 gpd.

(2) July - During the power failure stress test there is one day with no flow and one day with

reduced flow. These data point are not included in the monthly average.

(3) Sept-Oct - Vacation test, 10-day test with no flow for 8 days. Only nine doses applied on
first and last day. Low or no flow days excluded from the calculation of monthly averages.

4.3.2 Verification Test Restart

The first stress test was started in early November 2001, after two months of verification testing.
Following the stress test completion, it was discovered that the sampling plan described in the
VTP had not been followed. Several samples were missed, and the requirements for data
completeness (a Data Quality Objective) were not met. Furthermore, in early November, water
was found to be ponding near the blower, and the blower was raised by placing it on a cement
block. Bio-Microbics and NSF were not informed of this change to the system until after the

-------
work was completed. Bio-Microbics arrived at the site on November 14 and checked the system.
The blower, blower filter, piping, and insert were found to be in acceptable working order.
However, Bio-Microbics determined that the blower operation setting (30 minutes on/30 minutes
off) was not appropriate. Bio-Microbics changed the blower control to operate the blower
continuously, thus supplying more air to the system. This setting was maintained for the
remainder of the verification test.

Due to the incomplete data set and changes to the system, NSF, NovaTec, and Bio-Microbics
agreed that the test would continue, but that the November data would not be used in the
summary information for the verification report. September and October data would be used as
the first two months of the test, and the incomplete washday stress test would be repeated.
Wastewater continued to flow to the unit throughout November. The test resumed officially on
December 1, 2001, providing a two-week period for the unit to stabilize following the aborted
stress test and the changes to the blower operational setting. The washday stress test started in
late December, and the remaining elements of the VTP were implemented based on the test plan
schedule. This approach resulted in the collection of 13 months of data (September to October
2001, and December 2001 to October 2002) for the verification test.

4.3.3 BOD5/CBOD5 and TSS Results and Discussion

Figures 4-1 and 4-2 show the influent and effluent BOD5/CBOD5 and TSS concentrations during
the verification test. Table 4-5 presents the same results with a summary of the data (mean,
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 and have a
large number of nitrifying organisms, which can cause nitrification to occur during the five days
of the analysis. The CBOD5 analysis inhibits nitrification 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. Comparing the BOD5 of the
influent and the CBOD5 of the effluent demonstrates how effectively the system removes
oxygen-demanding organics.

The influent wastewater had a mean BOD5 of 150 mg/L with a range of 65 to 210 mg/L. The
mean influent TSS was 180 mg/L, with a range of 110 to 440 mg/L. The RetroFAST® effluent
had a mean CBOD5 of 12 mg/L, varying from 2 mg/L to 28 mg/L. The mean effluent TSS
concentration was 28 mg/L, ranging from 3 to 170 mg/L. The RetroFAST® achieve a mean
reduction of 91% for BOD5/CBOD5 (range of 79 to 98%) and a mean reduction of 84% TSS
(range of 14 to 98%).

Effluent data from the first two months of the verification test (September and October 2001)
showed variable TSS concentrations (8 to 59 mg/L) with CBOD5 concentrations of 2 to 18 mg/L.
Bio-Microbics was concerned with the elevated and variable concentrations, but no changes

-------
were made to the system. As stated previously, the blower was set to continuous operation on
November 14, 2001, and was not changed for the duration of the testing.

The washday stress test and working parent stress test were performed from December 24
through December 28, and February 25 through March 1, 2001, respectively. The data indicate
that there were no specific impacts from these stress tests on system performance for TSS and
CBOD5. Effluent quality did vary during and after these stress periods, but was typically within
the range of results found throughout the verification test.

Data collected during the low load stress test (May 6 to June 3) showed a possible short-term
impact on TSS and CBOD5, as the sample collected ten days into the test showed increases in
TSS and CBODs. However, data collected at the end of the stress period (May 27) and during
post-stress test monitoring showed TSS and CBOD5 concentrations typical of the overall
performance of the unit. The power/equipment failure test (July 22 to July 24) also showed an
increase in TSS in the first sample after the stress test ended (July 27). However, subsequent
samples appeared to be within the range of concentrations found during the entire verification
test.

The vacation stress test started on September 23 and continued through October 2, 2002. There
was an increase in effluent CBOD5 (13 and 28 mg/L) and TSS (42 and 35 mg/L) in the two
samples collected at the start of the test. In addition, the first sample collected after flow was
restarted at the end of the stress test showed higher than average CBOD5 (16 mg/L) and TSS (35
mg/L). These data were above the mean concentrations found during the verification test and
were higher than the concentrations measured the week before the stress test. However, the
concentrations are within the range of data found throughout the verification test. Any impact
that might be caused by the vacation stress test (no flow for eight days) cannot be determined
given variability exhibited by the RetroFAST® during the verification test.

-------
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	Influent B0D5 Left Axis mg/L 	Effluent CB0D5 Right Axis mg/L

Figure 4-1. RetroFAST® 0.375 System BOD5/CBOD5 results.

33

-------
Influent TSS Left Axis	Effluent TSS Right Axis

Figure 4-2. RetroFAST® 0.375 System TSS results.

34

-------
Table 4-5. RetroFAST® 0.375 System BOD5/CBOD5 and TSS Results



bod5

CBOD5





TSS





Influent

Effluent

Removal

Influent

Effluent

Removal

Date

(mg/L)

(mg/L)

(%)

(mg/L)

(mg/L)

(%)

09/10/01

130

2

98

340

17

95

09/30/01

65

8

88

130

59

55

10/10/01

120

18

85

240

44

81

10/26/01

170

7

96

230

8

97

10/29/01

140

5

97

140

20

86

11/05/01

150

7

95

110

13

88

11/06/01

140

13

91

160

8

95

11/09/01

81

15

81

130

N/A

N/C

11/21/01

84

10

88

120

33

71

11/28/01

90

11

88

140

42

70

12/14/01

91

15

84

120

62

50

12/24/01

180

17

91

140

55

60

12/26/01

170

10

94

150

14

91

12/29/01

99

10

90

160

9

95

12/30/01

130

13

90

190

7

96

12/31/01

150

14

91

270

17

94

01/01/02

100

12

89

170

12

93

01/02/02

200

14

93

440

16

96

01/03/02

76

13

83

150

12

92

01/30/02

120

7

94

170

13

92

02/18/02

170

23

86

190

170

14

02/25/02

150

6

96

170

41

76

02/27/02

130

14

90

140

33

77

03/02/02

130

5

96

130

9

93

03/03/02

140

8

94

160

16

90

03/04/02

150

6

96

150

14

91

03/05/02

140

5

97

110

23

80

03/06/02

160

7

96

130

25

80

03/07/02

130

12

91

170

33

80

04/03/02

170

25

86

180

67

64

04/29/02

180

9

95

200

15

92

05/06/02

150

7

95

170

9

95

05/16/02

150

12

92

180

39

78

05/27/02

120

24

79

130

86

34

05/28/02

140

11

92

150

26

82

N/A - not analyzed

N/C - not calculated

35

-------
Table 4-5. RetroFAST® 0.375 System BOD5/CBOD5 and TSS results (continued)

BODs CBOD5	TSS



Influent

Effluent

Removal

Influent

Effluent

Removal



(mg/L)

(mg/L)

(%)

(mg/L)

(mg/L)

(%)

5/29/02

130

14

89

160

26

84

5/30/02

130

15

88

160

9

95

5/31/02

140

15

89

170

9

95

6/1/02

150

8

95

170

10

94

6/2/02

130

10

93

150

9

94

6/3/02

210

17

92

170

46

73

6/27/02

160

11

93

200

28

86

7/19/02

190

17

91

180

34

82

7/22/02

160

7

96

200

25

88

7/27/02

120

12

90

140

43

68

7/28/02

150

13

91

210

23

89

7/29/02

130

15

89

180

26

86

7/30/02

150

20

87

190

29

85

7/31/02

170

22

87

200

34

83

8/1/02

190

26

87

350

42

88

8/28/02

140

17

87

170

32

82

9/16/02

180

6

97

160

8

95

9/23/02

160

13

92

180

42

77

9/24/02

140

28

79

170

35

80

10/3/02

200

16

92

260

35

87

10/4/02

180

8

95

190

11

94

10/5/02

110

13

88

190

22

88

10/6/02

130

9

93

160

22

87

10/7/02

140

7

95

150

24

84

10/8/02

170

10

94

280

30

89

10/21/02

180

6

97

190

8

96

10/22/02

160

3

98

180

3

98

10/23/02

140

5

96

160

11

93

10/24/02

150

10

93

180

9

95

10/25/02

140

12

92

190

24

87

Number of Samples

60

60

60

60

60

60

Mean

150

12

91

180

28

84

Median

150

12

92

170

24

88

Maximum

210

28

98

440

170

98

Minimum

65

2

79

110

3

14

Std. Dev.

30

5.9

4.4

56

25

15

Summary statistics do not include November 2001 data. See Section 4.3.2.
N/A - not analyzed
N/C - not calculated

Values below the detection limit are set to zero for concentration means

36

-------
4.3.4 Nitrogen Reduction Performance
4.3.4.1 Results

Figures 4-3 through 4-5 present the results for the TKN, NH3-N, and TN in the influent and
effluent during the verification test. Figure 4-6 shows the results for NO2 and NO3 in the
effluent. Table 4-6 presents all of the nitrogen results with a summary of the data (mean,
median, maximum, minimum, standard deviation). The summary statistics do not include the
data from November 5 through November 28, when changes were made to the system and the
sampling program was restarted.

The influent wastewater had a mean TKN concentration cf 39 mg/L and a mean NH3-N
concentration of 28 mg/L. Mean TN concentration in the influent was 39 mg/L (the TKN
concentration), based on the generally accepted assumption that the NO2 and NO3 concentration
in the influent is negligible. The RetroFAST® effluent had a mean TKN concentration of 11
mg/L, and a mean NH3-N concentration of 5.9 mg/L. The NO2 mean concentration in the effluent
was 0.46 mg/L, and NO3 mean concentration was 8.0 mg/L. TN was determined by adding the
concentrations of the TKN (organic plus ammonia nitrogen), NO2 and NO3 in the effluent. The
mean TN in the RetroFAST® effluent was 19 mg/L for the thirteen-month verification period,
with a median concentration of 18 mg/L. The RetroFAST® demonstrated a mean reduction of
51% in TN for the verification test period, with a median removal of 50%.

Alkalinity, pH, DO, and temperature were measured during the verification test. These
parameters can impact TN removal and provide insight into the condition of the system. Table
4-7 shows the results for pH, alkalinity, DO, and wastewater temperature

The pH of the influent ranged from 6.4 to 7.8, and the effluent from the RetroFAST® was in a
similar range of 6.5 to 8.0. The alkalinity of the influent averaged 150 mg/L as CaC03 with a
maximum concentration of 180 mg/L and minimum of 130 mg/L. The effluent alkalinity was
consistently lower than the influent when nitrification/denitrification was occurring, with a mean
concentration of 83 mg/L and a median concentration 70 mg/L. The one exception was the
December 29, 2001 through January 3, 2002 period, when the effluent alkalinity was very close
to the influent concentration. The data suggest nitrification/denitrification was occurring, but
there was no change in alkalinity. The data were checked and appeared to be correct, but these
alkalinity data are considered suspect. The effluent alkalinity did vary based on the performance
of the nitrification/denitrification process.

Bio-Microbics stated that the RetroFAST® is designed to operate as an aerobic and anoxic
system. The wastewater is aerated to promote nitrification and then recycled to an anoxic
quiescent zone prior to discharge. The DO in the effluent from the unit averaged 8.6 mg/L and
was above 5 mg/L on all but three days. Measurement of the D.O. in the anoxic zone was not
included in the verification test.

-------
70

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Figure 4-3. RetroFAST® 0.375 System TKN results.

38

-------
45 ¦
40 ¦

35 -

¦Influent Ammonia	Effluent Ammonia

Figure 4-4. RetroFAST® 0.375 System NH3-N results.

39

-------
¦ Influent TN	Effluent TN

Figure 4-5. RetroFAST® 0.375 System TN results.

40

-------
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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

O

0

O

O

O

O

O

O

O

O

O

O

O

O

O

O

O

O

O

O

O

O

O

O

O

O

O

O

O

O

O

0

O

O

O

O

O

CM

CM

CM

CM

CN

CN

CN

CN

CN

CN

CM

CM

CM

CM

CM

CM

CM

CM

CM

CM

CM

CM

CM

CM

CM

CM

CM

CM

CM

CM

O



00

CN]

LO

(T)

CO







00



L?)



L?)

§5

CN]

§

O

5





LO

(T)

CN]

CO



CO







£M

O

fNJ





CN]



CO



CM



CM



CM



CM

LO

CM

CO







CM



CM

(T)

CM

0

CM

(T)

G)

T—

O

x—

T—

T—

CM

CN

x—

x—

CM

CM

CO

CO







LO



to





r-~

00

00



CD

T—

O

Date

¦Effluent Nitrate Left Axis	Effluent Nitrite Right Axis

Figure 4-6. RetroFAST® 0.375 System NO2 and NO3 effluent concentrations.

41

-------
Table 4-6. RetroFAST® 0.375 System Influent and Effluent Nitrogen Data

TKN	NH3-N	TN	N03 N02

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

Date Influent Effluent Influent Effluent Influent Effluent Effluent Effluent

09/10/01

50

9.8

26

8.5

50

13

N/A

N/A

09/30/01

33

33

27

19

33

33

0.06

0.04

10/10/01

50

44

29

30

50

44

N/A

N/A

10/26/01

33

36

24

28

33

38

1.1

0.26

10/29/01

33

29

21

21

33

29

0.28

0.20

11/05/01

24

24

23

24

24

28

2.1

1.47

11/06/01

24

39

17

17

24

41

1.5

0.40

11/09/01

39

33

17

20

39

33

N/A

N/A

11/21/01

27

21

15

13

27

25

2.6

1.9

11/28/01

20

6.8

17

5.2

20

15

7.7

0.81

12/14/01

32

13

26

7.1

32

20

6.3

0.23

12/24/01

38

14

21

5.6

38

19

5.4

0.18

12/26/01

41

15

27

7.1

41

19

4.5

0.18

12/29/01

39

19

20

9.5

39

20

1.3

0.08

12/30/01

40

19

25

12

40

20

1.0

0.07

12/31/01

49

32

26

14

49

33

0.88

0.09

01/01/02

40

33

29

16

40

33

0.72

0.07

01/02/02

59

38

42

17

59

39

0.73

0.11

01/03/02

36

34

24

17

36

36

0.95

0.13

01/30/02

30

12

24

9.7

30

18

5.7

0.34

02/18/02

32

13

26

0.3

32

26

13

0.14

02/25/02

33

4.6

22

0.2

33

19

15

0.04

02/27/02

50

9.6

19

4.8

50

23

13

0.47

03/02/02

51

5.4

27

4.1

51

19

13

0.14

03/03/02

48

5.2

28

3.2

48

19

14

0.13

03/04/02

49

4.0

27

0.7

49

19

15

0.07

03/05/02

53

4.4

25

1.3

53

20

15

0.53

03/06/02

53

6.7

26

1.0

53

22

15

0.67

03/07/02

34

8.1

23

7.6

34

22

13

0.46

04/03/02

34

11

33

4.5

34

29

18

0.74

04/29/02

32

4.1

31

1.7

32

22

17

0.48

05/06/02

44

4.2

32

3.7

44

15

9.8

0.96

05/16/02

29

3.4

28

0.7

29

18

14

0.49

05/27/02

28

8.9

27

0.3

28

19

9.7

0.26

05/28/02

37

4.3

27

0.2

37

14

9.3

0.46

42

-------
Table 4-6. RetroFAST® 0.375 System Influent and Effluent Nitrogen Data (continued)

TKN	NHj-N	TN	N03 N02

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

Date	Influent Effluent Influent Effluent Influent Effluent Effluent Effluent

05/29/02

28

3.4

28

0.5

28

13

8.9

0.54

05/30/02

30

4.3

30

0.7

30

14

9.2

0.39

05/31/02

31

7.0

30

0.9

31

17

9.5

0.46

06/01/02

30

4.2

28

0.8

30

15

10

0.49

06/02/02

29

4.3

28

0.9

29

15

11

0.52

06/03/02

30

3.8

28

0.5

30

15

11

0.48

06/27/02

37

5.9

26

0.8

37

15

8.5

0.45

07/19/02

32

6.6

28

5.7

32

15

6.9

1.2

07/22/02

36

5.1

28

1.8

36

12

6.8

0.61

07/27/02

30

3.7

25

2.1

30

11

6.6

0.94

07/28/02

33

5.0

23

4.1

33

11

5.1

0.96

07/29/02

30

12

25

5.5

30

17

3.7

1.0

07/30/02

64

12

29

7.8

64

16

2.6

0.74

07/31/02

31

14

28

11

31

16

2.3

0.48

08/01/02

37

17

29

12

37

18

1.2

0.48

08/28/02

36

19

30

17

36

21

2.2

0.61

09/16/02

28

5.6

27

4.4

28

14

7.8

0.48

09/23/02

42

13

31

6.6

42

19

5.1

1.1

09/24/02

59

8.4

36

6.4

59

13

3.8

1.0

10/03/02

43

4.1

22

1.4

43

14

9.0

0.56

10/04/02

55

2.2

32

1.0

55

12

9.1

0.38

10/05/02

46

3.9

30

1.0

46

6

1.8

0.66

10/06/02

44

4.9

28

0.7

44

16

10

0.48

10/07/02

47

4.3

28

0.5

47

15

10

0.21

10/08/02

37

4.1

31

0.9

37

15

10

0.30

10/21/02

38

1.7

30

0.3

38

15

13

0.31

10/22/02

39

2.5

34

0.4

39

16

13

0.25

10/23/02

35

2.6

31

0.5

35

16

13

0.33

10/24/02

34

5.2

33

2.8

34

17

11

1.0

10/25/02

35

5.5

31

1.0

35

18

11

1.1

No. Samples

60

60

60

60

60

60

58

58

Mean

39

11

28

5.9

39

19

8.0

0.46

Median

36

6.2

28

3.4

36

18

9.1

0.46

Maximum

64

44

42

30

64

44

18

1.2

Minimum

28

1.7

19

0.15

28

6.4

0.06

0.04

Std. Deviation

9.0

10

3.9

7.0

9.0

7.5

5.0

0.31

Summary statistics do not include November 2001 data - See Section 4.3.2
N/A - not analyzed
N/C - not calculated

Values below the detection limit set equal to zero (0) for statistical calculations

43

-------
Table 4-7. RetroFAST® 0.375 System Alkalinity, pH, and DO Results



DO

(mg/L)



PH
(S.U.)

Alkalinity
(mg/L as CaCO,)

Temperature

CQ

Date

Effluent

Influent Effluent

Influent

Effluent

Influent

Effluent

09/10/01

1.6

6.6

6.9

160

82

17.4

17.0

09/30/01

2.0

6.8

7.3

170

170

16.8

16.4

10/10/01

5.1

6.5

6.8

170

170

16.8

15.0

10/26/01

7.8

6.5

6.8

150

150

14.0

12.4

10/29/01

8.0

6.4

6.7

140

140

15.3

11.0

11/05/01

8.2

6.3

6.8

140

160

13.9

10.3

11/06/01

6.9

6.4

6.7

140

160

13.4

10.5

11/09/01

8.4

6.5

6.8

160

N/A

13.4

10.9

11/21/01

5.5

6.1

6.5

120

110

12.9

10.7

11/28/01

3.0

6.1

6.3

130

56

11.4

10.2

12/14/01

11

7.0

6.7

150

200

12.2

9.7

12/24/01

11

7.4

7.7

130

60

10.1

8.4

12/26/01

10

7.5

7.6

140

85

10.7

4.9

12/29/01

00
00

7.6

8.0

140

140

12.7

7.1

12/30/01

9.4

7.6

8.0

150

150

10.8

8.4

12/31/01

9.5

7.8

8.0

150

150

10.0

9.5

01/01/02

9.6

7.3

7.9

150

160

13.3

8.4

01/02/02

9.9

7.2

7.9

170

160

10.7

7.3

01/03/02

9.7

7.2

7.9

130

150

9.6

7.4

01/30/02

9.9

7.3

7.5

130

81

8.4

5.3

02/18/02

11

7.2

7.3

150

34

9.4

7.8

02/25/02

11

7.2

6.9

130

30

8.2

5.4

02/27/02

10

7.1

7.2

130

62

8.3

5.9

03/02/02

11

7.0

7.4

140

60

8.6

6.9

03/03/02

11

7.2

7.3

140

61

8.9

5.4

03/04/02

11

7.1

7.1

140

50

00
00

5.5

03/05/02

11

7.2

7.4

150

53

8.7

6.5

03/06/02

9.5

7.8

7.3

140

58

8.6

5.3

03/07/02

10

7.2

7.4

140

72

8.9

5.3

04/03/02

10

7.7

7.1

160

41

10.9

9.1

04/29/02

9.0

7.4

6.7

170

19

10.8

10.9

05/06/02

8.7

7.8

7.2

150

44

11.2

11.3

05/16/02

00
00

7.5

7.1

130

31

12.2

12.3

05/27/02

9.4

7.5

7.1

150

54

13.2

14.0

05/28/02

9.3

7.5

7.4

150

58

13.3

15.3

N/A - not analyzed

44

-------
Table 4-7. RetroFAST® 0.375 System Alkalinity, pH, and DO Results (continued)







PH

Alkalinity

Temperature



DO(mg/L)



(S.U.)

(mg/L as

CaCO,)



CQ

Date

Effluent

Influent Effluent

Influent

Effluent

Influent

Effluent

05/29/02

8.0

7.3

7.3

150

59

13.5

14.8

05/30/02

8.0

7.2

7.2

140

55

13.2

14.4

05/31/02

8.0

7.3

7.1

140

54

12.9

14.5

06/01/02

8.3

7.2

7.0

140

45

13.0

14.1

06/02/02

8.2

7.2

7.0

140

42

13.5

14.2

06/03/02

8.6

7.1

6.8

140

38

13.4

14.7

06/27/02

7.4

6.9

6.9

150

57

15.6

18.9

07/19/02

8.2

6.8

7.2

140

75

18.0

20.2

07/22/02

7.8

7.2

7.0

150

65

16.1

20.1

07/27/02

7.5

7.0

7.3

150

80

16.7

18.7

07/28/02

7.6

7.4

7.4

150

88

17.9

19.6

07/29/02

7.0

6.7

7.0

160

98

16.7

20.2

07/30/02

7.3

6.8

6.8

150

100

16.1

19.3

07/31/02

7.3

6.7

7.0

150

110

16.3

17.9

08/01/02

7.2

6.8

6.8

160

120

15.8

18.1

08/28/02

7.0

7.5

7.3

160

130

17.8

18.4

09/16/02

7.6

7.6

7.7

170

79

16.7

16.9

09/23/02

7.9

7.6

7.7

160

91

16.2

15.7

09/24/02

7.4

7.8

7.5

180

110

16.2

15.6

10/03/02

8.6

7.4

7.9

160

77

16

15.4

10/04/02

8.3

7.6

7.6

160

76

16.4

16.8

10/05/02

8.3

7.7

7.3

180

72

17.2

16.9

10/06/02

8.1

7.6

7.4

180

72

16.8

16.2

10/07/02

8.4

7.4

7.2

180

70

16.9

15.9

10/08/02

8.4

7.6

7.5

180

75

16.5

16.3

10/21/02

8.4

6.9

6.5

170

51

16.1

15.7

10/22/02

8.4

7.2

7.2

170

55

15.3

14.6

10/23/02

7.9

7.3

7.0

170

56

14.2

13.3

10/24/02

8.0

7.4

7.0

170

61

16.1

15.4

10/25/02

9.1

7.5

7.1

170

43

15.3

11.7

No. Samples

60

60

60

60

60

60

60

Mean

8.6

7.2

7.2

150

83

14

12.8

Median

8.6

7.3

7.3

150

70

14

14.5

Maximum

11

7.8

8.0

180

200

18

20.2

Minimum

1.6

6.4

6.5

130

19

8.2

4.90

Std. Deviation

1.8

0.35

0.37

140

42

3.1

4.75

Summary statistics do not include November 2001 data - See Section 4.3.2
N/A - not analyzed

45

-------
4.3.4.2 Discussion

During the first two months of the verification test, September and October 2001, the
nitrification and denitrification processes, which had been established during startup, were upset,
and only small amounts of NHj-N or TN were removed by the RetroFAST® system. All
members of the ETV test team were concerned about the problem and tried to determine what
might have caused the upset condition. There were no apparent changes in the influent
wastewater quality. During the November 14 system check by Bio-Microbics, it was determined
that the blower setting of 30 minutes on and 30 minutes off was not correct for the system. Bio-
Microbics indicated that the incorrect blower setting was the cause of the problem. Bio-
Microbics changed the blower setting to operate continuously on November 14, and the
verification test was officially continued in December. Following the change to the blower
setting, the RetroFAST® began to recover. The ammonia nitrogen concentration in the effluent
began to decrease at the end of November and nitrate concentrations increased, indicating the
nitrification/denitrification processes were re-establishing. TN removal approached 50% at that
time.

The washday stress test was performed from December 24 to December 28, 2001. The NHs-N
and TKN began to rise at the end of the stress test and NO3 decreased. By the end of the post-
stress test monitoring (January 3, 2002), the data showed no removal of TN by the system. The
washday stress test appears to have upset the system. It should be noted that the temperature of
the wastewater was decreasing during this time, and there was a one-day spike in TSS near the
end of the monitoring period. These factors may have contributed to the system upset.

During the next six weeks, the RetroFAST® system re-established the nitrifying population, as
shown by the drop in NH3-N concentration. The February 18 sample showed NH3-N of 0.3
mg/L and a TKN concentration of 13 mg/L (59% removal). The denitrification process also
appears to have been re-established to some extent, with effluent NO3 levels of 13 mg/L on
February 18.

The working parent stress test was performed from February 25 through March 1, 2002. The
NH3-N concentration in the effluent increased during the stress period (4.8 mg/L), but was lower
at the end of the stress period and during tie post-stress monitoring. Nitrate levels, however,
remained in the 13 to 15 mg/L range. TN removal was above 50% for most days, with
concentrations ranging from 19 to 22 mg/L in the post-stress monitoring period. The working
parent stress test did not appear to have a major impact on the nitrification process. During the
next two months, the data show that more than 80% of the NH3-N was being removed, but NO3
levels increased to 17 to 18 mg/L as the denitrification process was not able to convert the NO3
to nitrogen gas. The DO level in the effluent was in the 9.5 to 11 mg/L during this time.

The low load stress test began on May 6 and continued until May 26, 2002. Both the
nitrification and denitrification processes appeared to improve during and following this stress
test. NH3-N concentrations dropped below 1 mg/L, NO3 levels decreased to the 9 to 11 mg/L
range, and TN removal was 46 to 61% after the first ten days of the stress test. The lower daily
volume of wastewater being processed through the unit may be a factor in the improved and
steadier performance of the unit.

46

-------
During the June and July test period, which included the power failure test on July 22, the TN
concentration in the effluent ranged from 11 to 17 mg/L. NH^-N concentrations increased each
day during the post-stress test monitoring and reached a maximum of 12 mg/L on August 1. At
the same time, the NO3 concentrations decreased, although the actual removal of NO3 by the
system (assuming all NH3-N removed is converted to NO3) remained in the 14 to 19 mg/L range.
The power failure stress test appeared to have an impact on the system, which might be expected
since the nitrification system is dependent on oxygen supplied by the blower. Late in the post-
stress test monitoring period, NH3-N removal performance began to deteriorate and did not
recover until September.

The vacation stress test started on September 23 and ended on October 2, 2002. During this
period, there was no influent flow to the RetroFAST® system. Following the resumption of flow
on October 2, NH3-N concentrations in the effluent were generally less than 1 mg/L, similar to
the levels found during the low load test. Nitrate levels increased, but denitrification continued to
remove 14 to 20 mg/L of NO3 from the system. The vacation stress test did not have a negative
impact on the system based on these data.

The system performance remained more consistent for the duration of the verification test. The
TKN and NH3-N effluent concentrations were low and similar to the data from the period after
the low load stress test. The NO3 levels remained in the 10 to 13 mg/L range, removing an
estimated 17 to 21 mg/L of NO3. The TN concentration in the effluent ranged from 15 to 18
mg/L, representing 49 to 61% removal.

The RetroFAST® system showed variable results during the verification test with TN removal
varying from zero to 86%. There were at least two apparent upset periods, one at the start of the
verification test (possibly caused by the blower setting discussed previously) and another during
the washday stress test. A smaller upset in the nitrification process may have occurred in the late
July 2002 period at the end of the power failure post-stress-monitoring period. During the last
six months of the verification test, the system appeared more stable and performance was more
consistent. During these last six months of operation, the TN concentration in the effluent
averaged 15 mg/L (range of 6 to 21 mg/L).

4.3.5 Residuals Results

During the treatment of wastewater in the RetroFAST®, solids accumulate in the first and second
compartment of the tank. Inert and biological solids accumulate from influent wastewater just as
in a normal septic tank. Eventually, a buildup of solids reduces the capacity of the primary tank,
and the solids need to be removed. Solids will also build up in the second compartment, as the
section below the media is used as the settling zone for solids associated with the RetroFAST®
treatment.

The approximate depth of the residuals accumulated in the system was estimated in each
compartment of the septic tank at the end of the test period. Measurement of solids depth in a
septic tank is always difficult, as access to the tank is limited to a manway in the top. For the

-------
verification testing, solids depth in the first compartment was estimated at nine locations
accessible from the manway using a Sludge-Judge solids-measuring device. A single depth
measurement was made in the second compartment, as access with the treatment unit in place
was limited to a single small opening. In each case, a column of water and solids was removed
from the tank, and the undisturbed solids depth in the clear tube was measured. The
measurements were made after approximately sixteen months (July 5, 2001 to October 25, 2002)
of operation. The results for the first compartment are presented in Table 4-8. Solids depth in
the second compartment was 12 inches, measured at the single access point.

Table 4-8. Solids Depth Measurement—First Compartment

Solids Depth - First Compartment

(Inches)

Inlet

Center Center Center Outlet

Outlet

Left

Center

Right

Left Center Right Left

Center

Right

6 6 6 10

To characterize the solids in the primary tank, total solids (TS), TSS, and volatile suspended
solids (VSS) were measured in a sample collected on October 31, 2002. A sample was collected
from the second compartment on November 6, 2002. These data, presented in Table 4-9,
represent the solids/residue phase of the sample, excluding the liquid phase in the top of the
sample column. An additional sample was collected from the first compartment on November 6,
2002. Before taking this second sample, the first compartment of the tank was thoroughly mixed
using a large pump. This sample represents a mixed sample (solids and water) of the entire
compartment contents, rather than being a single point grab sample.

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Table 4-9. TSS and VSS Results for the RetroFAST® 0.375 System Solids Samples

Date

Location

TS
(mg/L)

TSS
(mg/L)

VSS
(mg/L)

10/31/02

Tank Compartment 1
Sludge sample

4,100

3,100

2,200

11/06/02

Tank Compartment 2
Sludge sample

3,600

2,300

11/06/02

Tank Compartment 1
Completely mixed contents

4,900

N/A

N/A - not analyzed

The mass of solids present in the first compartment of the septic tank can be roughly estimated
from these data. The concentration of TS is 4,900 mg/L in a total volume of 880 gallons. The
estimated dry weight of solids, accumulated during the test, is approximately 36 pounds. The
data also show that the VSS represented 71% of the TSS in the first compartment and 64% of the
TSS in the second compartment.

4.4 Operations and Maintenance

Operation and maintenance performance of the RetroFAST® was monitored throughout the
verification test and recorded in a field log. Data were collected on electric and chemical usage,
noise, and odor. Observations were also recorded on the condition of the system, any changes in
setup or operation (blower adjustments, cleaning, etc.), or any problems that required resolution.
A complete set of field logs is included in Appendix F. There were no major mechanical
component failures during the verification test.

4.4.1 Electric Use

Electric use was monitored by a dedicated electric meter serving the RetroFAST® beginning in
October 2001, and meter readings were recorded daily in the field log by MWTTP operators. A
second electric meter was installed on March 5, 2002, because the first meter had shown no or
very low power consumption on six days over a five-month period,, even though the blower had
operated on these days as verified by the operators. Both meters were read daily through the end
of the test period, and there was only one additional day, June 28, when meter readings were
very low (0.4 kilowatts/day [kW/d]). Both meters gave similar results for the period of March
through October 2002. Table 4-10 summarizes the electric use from startup through the end of
the verification test. The complete set of daily electric readings is presented in a spreadsheet in
Appendix E. The average electrical use was 2.1 kW/d, and power consumption was very
consistent throughout the test.

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Table 4-10. Summary of RetroFAST® 0.375 System Electrical Usage



Meter 1 kW/day

Meter 2
kW/day

Days

364

232

Average

2.0

2.1

Median

2.1

2.1

Maximum

2.5

2.5

Minimum

0.0(1)

0.0(1)

Std. Dev.

0.38

0.24

(1) Measurement made during power failure stress test.

4.4.2	Chemical Use

The RetroFAST® did not require or use any chemical addition as part of the normal operation of
the unit.

4.4.3	Noise

A calibrated decibel meter was used to measure the noise levels associated with blower
equipment twice during the verification period. Measurements were taken 1 meter from the unit
and 1.5 meters above the ground, at 90° intervals in four directions around the blower housing.
Table 4-11 shows the results of this test.

Table 4-11. RetroFAST® 0.375 System Noise Measurements

Location

June 24, 2002

Sept. 18, 2002



(decibels)

(decibels)

East

60 ± 2 for all

61

South

four locations

64

West



61

North



58

Note: The June 24 readings are not specific
for the location of the four measurements

4.4.4 Odor Observations

Qualitative odor observations based on odor strength (intensity) and type (attribute) were made
six times during the verification test. ). Intensity was stated as not discernable, barely detectable,
moderate, or strong. Table 4-12 summarizes the results for the odor observations. As can be
seen, no significant odors were found during any of the observation periods.

50

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Table 4-12. Odor Observations

Date

Number of
Points Observed

Observation

9/24/01

No discernable odor

11/21/01

No discernable odor

4/12/02

No discernable odor

03/06/02

No discernable odor

06/24/02

No discernable odor

09/18/02

Barely detectable

odor, musty

4.4.5 Operation and Maintenance Observations

The RetroFAST® system is relatively simple to operate and maintain. The only
mechanical/electrical components are the blower, blower control panel, and the airlift system in
the treatment unit. Vent openings on the blower housing should be checked for blockage, and a
filter on the inlet to the blower needs inspection and periodic cleaning (interval will depend on
site conditions). The airlift and media should be inspected for clogging and cleaned if necessary.

No maintenance or cleaning was required or performed during the verification test. On
November 14, 2001 (after five months of operation), Bio-Microbics performed a system
inspection in the presence of the test facility personnel, checking the blower housing vents, air
filter, airlift system, and media. No cleaning was performed. The MWTTF operator noted in the
field log that there was some evidence of minor clogging on the top of the media, but no cleaning
was performed. Bio-Microbics has indicated that this was biological growth expected to be
present. The blower setting was changed using the dip switches on the control panel from 30
minutes on/30 minutes off to continuous operation during this visit.

Two operational problems involving the blower occurred during the 16 months of operation. On
August 16, 2001, during the startup period, the blower alarm indicated that the blower was off.
The circuit breaker had tripped. The breaker was reset, and the blower started without difficulty.
The system ran for 11 months with no shutdowns, until June 28, 2002, when the blower was
found to be off. No apparent cause (tripped breaker, electrical interruption, clogged filters, etc.)
was found for the blower shutdown. The blower was restarted, and it operated continuously until
the end of the verification test.

Bio-Microbics provides a two-year warranty covering parts only. The Homeowners Manual
(Appendix A) states that any component parts that fail within the warranty period should be
returned to Bio-Microbics, which will replace them. The homeowner is responsible for any labor
costs associated with replacement.

The Homeowners Manual also provides basic information on the operation of the system. The
installation instructions for contractors cover the basic requirements for system installation and

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setup. A three-page troubleshooting guide gives some information on diagnosing system
malfunctions, but there is no specific guidance given on what to do if problems cannot be solved
by the owner. Bio-Microbics does provide a phone number for the Bio-Microbics office.

In the opinion of the MWTTP operators, the system was easy to operate and maintain. The vents
and air filter are accessible and can be inspected/cleaned at ground level. The owner should be
alert to unusual noises (or lack of sound from the blower), alarms, or any unusual odors coming
from the system. If changes to the system are observed, the homeowner can consult the
troubleshooting guide. The MWTTF operators believe that to help ensure proper performance of
any advanced system, such as the RetroFAST® unit, homeowners should contract with a
qualified service provider, who can monitor the system. Based on the observations during the
verification test, annual inspection and cleaning may be adequate (no maintenance was required
during the test), but semiannual maintenance checks would appear to be more appropriate to
ensure system performance. It is estimated that semiannual maintenance checks could be
performed in one hour by a qualified service provider. These maintenance activities should
include inspecting and cleaning the air intake vents, air filter, and exhaust vents, and checking
the airlift system and media condition. The blower and alarms (if included) should be checked
for proper operation.

Both compartments of the septic tank should be checked for solids depth by a qualified service
provider. If solids have built up in the primary (first) compartment of the septic tank or in the
secondary compartment (where the unit is located), pumping of the system should be scheduled.
The Homeowners Manual for the RetroFAST® 0.375 provides no guidance on the solids depth in
the tank that would indicate that the tank should be pumped. The Bio-Microbics manual for their
larger units (0.5 and larger) indicates that solids removal should occur if the solids depth reaches
20 inches in the first compartment or 14 inches in the secondary compartment. Based on the
measurements in the two compartments of the tank used for the 16 months of operation during
the verification test (Table 4-8), it is estimated that removal of solids could be required every 18
to 24 months. Actual pumping frequency will vary based on the size of the tank used in a given
application and the nature of the wastewater.

The verification test (startup and testing) ran for a period of 16 months, which provided
sufficient time to evaluate the overall performance of the unit. Based on observations during this
test period, the equipment appeared to be properly constructed of appropriate materials for
wastewater treatment applications. The verification did not run long enough to truly evaluate
length of equipment life, but the basic components of the system appear durable and the overall
system design and use of PVC components indicate that it should have a reasonable life
expectancy. .

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4.5 Quality Assurance/ Quality Control

The VTP included a Quality Assurance Project Plan QAPP that identified critical measurements
and established Data Quality Objectives (DQO). The verification test procedures and data
collection followed the QAPP, and summary results are reported in this section. The laboratory
reported QA/QC data with every set of sample results as part of the laboratory reports. Each
report includes the results of blanks, laboratory duplicates, spikes, and other lab control sample
results for the various analyses. These QA data are incorporated with the laboratory reports
presented in Appendix C. Field duplicates were also collected by tie TO and submitted for
analyses. These results are presented in a spreadsheet in Appendix D.

4.5.1 Audits

In April 2002, NSF conducted an audit of MWTTF and the CanTest Laboratory during the
verification test. This audit found that the field and laboratory procedures were being followed
as presented in the test plan. The audit was scheduled to coincide with a sampling period at the
test site. This allowed the auditor to observe the actual sampling procedures and the preparation
of samples for shipment to the laboratory by courier. At the laboratory where samples were
being processed, the analyses were observed for several parameters.

The audit found that the procedures being used in the field and the laboratory were in accordance
with the established QAPP. Legible field logs were being maintained. The laboratory had a
firmly established QA/QC program, and observation of the analyses and a records review found
that appropriate QC data was being performed with the analyses. All members of the testing
team were reminded that an ETV requires that copies of all logs and raw data records be
delivered to NSF at the end of the project.

4.5.2 Daily Flows

One of the critical data quality objectives was to dose the system on a daily basis to within 10%
of the design flow, or 375 gpd ± 10%, based on a monthly average of the daily flows. The dose
volume was calibrated once per week and, if the volume changed by more than ten percent, the
individual dosing time was adjusted in the test site SCADA. The objective was met fir all
months of the verification test period. The monthly averages were presented in Table 4-4, and
the daily flows for all months are presented in spreadsheets in Appendix E. The field logs in
Appendix F provide the once per week calibration data that is summarized in the spreadsheets.

4.5.3 Precision

4.5.3.1 Laboratory Duplicates

The analytical laboratory performed sample duplicates for all parameters at a frequency of at
least one duplicate for every ten samples analyzed or one per batch if less than ten samples in a
batch. The results of laboratory duplicates were reported with all data reports received from the
laboratory. Table 4-13 shows the acceptance limits used by the laboratory.

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The Relative Percent Difference (RPD) was calculated using the standard formula as follows:

RPD = [(Ci- C2) - ((Ci + C2)/2)] x 100%

Where:

Ci = Concentration of the compound or element in the sample
C2 = Concentration of the compound or element in the duplicate

Table 4-13. Laboratory Precision Limits

Acceptance Limits

Parameter (RPD)

TSS 18

Alkalinity 10

BOD5/CBOD5 15

TKN 20

NH3-N 20

N02 12

The laboratory precision for TKN, NH3-N, NO2, and NO3 was excellent, with all results for the
entire verification test being within the acceptance limits. Only one alkalinity duplicate and one
BOD5 duplicate were outside the limits, out of more than 100 sets of reported laboratory
duplicates. On four occasions during the yearlong verification test, the TSS duplicates were
outside of the established limits, but in each case, there were multiple duplicates in batch. As an
example, the September 4, 2001, data reported ten duplicate results for TSS, with three being
outside the QC limit. In each case, the majority of the duplicates were within acceptance limits,
and the data were considered valid after review by the laboratory QA officer. NSF reviewed the
QC data and agreed that the data were valid.

The laboratory precision for all parameters, as measured by the laboratory duplicates, was found
to meet the QA objectives for the verification test.

4.5.3.2 Field Duplicates

Field duplicates were collected for influent and effluent samples to monitor the overall precision
of the sample collection and laboratory analyses. The results for the field duplicates are
presented in a spreadsheet in Appendix E. Summaries of the data are presented in Tables 4-14
and 4-15.

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Table 4-14. Duplicate Field Sample Summary - Nitrogen Compounds





TKN





NH3-N



Statistics

Rep 1

Rep 2

RPD

Rep 1

Rep 2

RPD



(mg/L)

(mg/L)

(%)

(mg/L)

(mg/L)

(%)

Number

26

26

26

26

26

26

Mean

23

23

9.2

17

16

8.0

Median

23

24

6.8

18

16

4.9

Maximum

52

49

87

35

31

55

Minimum

2.5

1.9

0.0

0.39

0.38

0.33

Standard







12

12

11

Deviation

15

15

16











N02





NO3



Statistics

Rep 1

Rep 2

RPD

Rep 1

Rep 2

RPD



(mg/L)

(mg/L)

(%)

(mg/L)

(mg/L)

(%)

Number

15

15

15

14

14

14

Mean

7.8

7.7

6.1

0.45

0.46

4.7

Median

6.1

6.2

1.6

0.46

0.47

1.6

Maximum

19

18

39

1.1

1.1

31

Minimum

<0.05

<0.05

0.0

<0.002

<0.002

0.0

Standard













Deviation

6.33

6.20

11

0.26

0.26

8.1

Note: All influent NO2 and NO3 duplicates (11 sets for each parameter) were below
detection limits yielding a RPD of zero and are not included in the above summary.

Table 4-15. Duplicate Field Sample Summary - BOD5/CBOD5, TSS, Alkalinity



BOD5/CBOD5



TSS







Rep 1

Rep 2

RPD Rep 1

Rep 2



RPD

Statistics

(mg/L)

(mg/L)

(%) (mg/L)

(mg/L)



(%)

Number

26

26

26 26

26



26

Mean

72

69

26 97

95



16

Median

18

18

13 46

42



6.9

Maximum

195

198

110 325

353



114

Minimum

2.0

5.0

0.0 3

4



0.0

Std. Dev.

75

72

30 91

90



24

Statistics

Rep 1
(mg/L as CaCOj)

Alkalinity
Rep 2
(mg/L as CaCOj)



RPD

(%)



Number

26



26



26



Mean

110



110



2.4



Median

130



130



1.0



Maximum

170



270



15



Minimum

21



18



0



Std. Dev.

46



47



3.9



55

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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,
particularly for TSS and BOD5. For this QA review, 30% RPD was selected as a target for the
QA/QC review of field precision for nutrients and alkalinity, and 40% was the selected target for
TSS and BOD5.

The overall precision based on field duplicates for nitrogen compounds was excellent. Only one
sample (out of 26, or 25 duplicates) for each of the nutrient analyses (TKN, NH3-N, NO2, and
NO3) exceeded 30% RPD. Alkalinity precision was also excellent with all replicates having a
RPD of less than 15%.

The CBOD5 and TSS data tended to have lower precision than the other analyses, which is
expected in wastewater matrices, particularly in treated effluent that can be at low
concentrations. The TSS results showed that four replicates out of 26 exceeded 40% RPD, but
all four were effluent samples with low concentration (maximum of 18 mg/L). The low
concentrations can exaggerate the relative percent difference calculation, as shown by one
sample that had replicate TSS values of 4 and 7 mg/L, yielding a RPD of 55%. Eight of the 26
BOD5/CBOD5 field duplicates showed RPD above 40%; six of these eight replicates were on
effluent samples. The low concentrations had an impact on the RPD calculations, as shown by
the sample that had replicate CBOD5 values of 2 and 7 mg/L, yielding a RPD of 110%. All of
the field data are shown in a spreadsheet in Appendix E. While these data indicate that precision
is lower at the lower concentrations, the information in overall data set demonstrates the ability
of the treatment system to 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.

4.5.4 Accuracy

Method accuracy was determined and monitored using a combination of matrix spikes,
laboratory control samples (known concentration in blank water), and proper equipment
calibration and traceability depending on the analytical method. Recovery of the spiked analytes
was calculated and monitored during the verification test. The laboratory used the control
samples and recovery limits shown in Table 4-16 and reported the data with each set of
analytical results.

The equations used to calculate the recoveries for spiked samples and laboratory control samples
are as follows:

Matrix Spike Samples:

Percent Recovery = (Cr- C0)/Cf x 100%)

Where:

Cr = Total amount detected in spiked sample
C0 = Amount detected in un-spiked sample
C f= Spike amount added to sample.

-------
Lab Control Sample:

Percent Recovery = (Cm / Cknown) x 100%

Where:

Cm = measured concentration in the spike control sample
Cknown = known concentration

Table 4-16. Laboratory Control Limits for Accuracy

Parameter

Method

Calibration

Lab Control

Matrix

Recovery

Blank

Curve Check

Sample

Spike

Limits

(%)

TSS

N/A

80-120

Alkalinity

N/A

85-115

BOD5/CBOD5

N/A

X(1)

N/A

TKN

66-124

NH3-N

80-120

N02

86-112

N03

N/A

90-110

(1) Seed Control Sample
X Denotes sample collected
N/A Not applicable

Based on review of the data reports, all of the accuracy limits were met in all analytical batches
for TSS, Alkalinity, BOD5/CBOD5, NH3-N, NO2, and NO3. Five sample batches for TKN (out
of more than 100 batches; more than 120 samples of influent and effluent) had matrix spike
recoveries higher than the upper control limit. These data were reviewed, and all other QC
parameters (calibration curve, continuing calibration curve checks, control samples, etc.) were
found to be within acceptance limits. Based on this review, the laboratory QA officer accepted
these data as valid. Overall, the accuracy data for all parameters was found to be excellent and
met the quality objectives.

The balance used for TSS analysis was calibrated routinely with weights that were National
Institute of Standards and Technology (NIST) traceable. Calibration records were maintained by
the laboratory and inspected during the on-site audit. 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 NIST-traceable

-------
thermometer. The DO meter was calibrated daily using ambient air and temperature readings in
accordance with the standard operating procedure (SOP). The noise meter was calibrated prior
to use. All of these traceable calibrations were performed to ensure the accuracy of
measurements.

4.5.5 Representativeness

The field procedures were designed to ensure that representative samples were collected of both
influent and effluent wastewater. The composite sampling equipment was checked 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 field duplicate
samples. However, review of the overall data set for influent and effluent samples did not show
specific sampling bias for either TSS or BOD5/CBOD5. These data indicated that while
individual sample variability may occur, the data were representative of the concentrations in the
wastewater.

The laboratory used standard analytical methods and written SOPs for each method to provide a
consistent approach to all analyses. Sample handling, storage, and analytical methodology were
reviewed during the on-site audit to verify that standard procedures were being followed. The
use of standard methodology, supported by proper QC information and audits, ensured that the
analytical data were representative of the actual wastewater conditions.

4.5.6 Completeness

The test plan 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 once a week, as
specified. The flow records were 100% complete. Electric meter records were maintained in the
field logbook. Electric meter readings were performed daily and summarized in a spreadsheet.
The electric monitoring was not started until late October 2001, so only eleven months of power
usage data were collected compared to the goal of twelve months of data. Completeness was
92% for the power measurements, which met the QA objective of 83%.

All monthly samples and all stress test samples were collected in accordance with the schedule.
Therefore, sample collection was 100% complete, exceeding the goal of 83% for both types of
collections.

A goal of 90% was set for the completeness of analytical results from the laboratory. All
scheduled analyses for delivered samples were completed and found to be useable data;
therefore, laboratory data are 100% complete.

-------
Appendices

A Bio-Microbics - Homeowners Manual
B Verification Test Plan
C Lab Data and QA/QC Data
D Field Operations and Lab Logbooks
E Spreadsheets with calculation and data summary
F Laboratory Raw Data

Appendices are not included in the Verification Report. Appendices are available from NSF
upon request.

59

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Glossary

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 startup 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 (QAPP)- a written document that describes the
implementation of quality assurance and quality control (QA/QC) 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 (SOP) - 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 (TO) - an independent organization qualified by the Verification
Organization (VO) 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.

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 (VTP) - 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 VTP includes
detailed instructions for sample and data collection, sample handling and preservation, and
QA/QC requirements relevant to the particular test site.

61

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References

(1) NSF International, Protocol for the Verification of Residential Wastewater Treatment
Technologies for Nutrient Reduction, Ann Arbor, MI, November 2000.

(2) United States Environmental Protection Agency, Manual for Nitrogen Control, 625/R-
93/010, 1993.

(3) NSF International, Test Plan for the Bio-Microbics RetroFAST® 0.375 under the US
Environmental Protection Agency Environmental Technology Verification Program at the
Mamquam Wastewater Technology Test, August 2001.

(4) United States Environmental Protection Agency, Methods and Guidance for Analysis of
Water, EPA 821-C-99-008, Office of Water, Washington, DC, 1999.

(5) United States Environmental Protection Agency, Methods for Chemical Analysis of Water
and Wastes, EPA 600/4-79-020, revised March 1983.

(6) APHA, AWWA, and WEF, Standard Methods for the Examination of Water and
Wastewater, 19th Edition, Washington, DC, 1998.

Bibliography

American National Standards Institute/ASQC, Specifications and Guidelines for Quality Systems
for Environmental Data Collection and Environmental Technology Programs (E4), 1994.

NSF International, Environmental Technology Verification - Source Water Protection
Technologies Pilot Quality Management Plan, Ann Arbor, MI, 2000.

United States Environmental Protection Agency, Wastewater Technology Fact Sheet Trickling
Filter Nitrification, Office of Water, EPA 832-F-00-015, Washington DC, September
2000.

United States Environmental Protection Agency, USEPA Guidance for Quality Assurance
Project Plans, USEPA QA/G-5, USEPA/600/R-98-018, Office of Research and
Development, Washington, DC, 1998.

United States Environmental Protection Agency: Environmental Technology Verification
Program - Quality and Management Plan for the Pilot Period (1995 - 2000),
USEPA/600/R-98/064, Office of Research and Development, Cincinnati, OH, 1998.

United States Environmental Protection Agency, Guidance for the Data Quality Objectives
Process, USEPA QA/G-4, USEPA/600/R-96-055, Office of Research and Development,
Washington, DC, 1996.

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