August 2005
                               05/23/WQPC-WWF
                                EPA/600/R-05/137
   Environmental Technology
   Verification Report

   Stormwater Source Area Treatment
   Device

   The Stormwater Management
   StormFilterR using Perlite Filter Media

              Prepared by
             NSF International
       Under a Cooperative Agreement with
4>EPA U.S. Environmental Protection Agency

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          Environmental Technology Verification Report


   Stormwater Source Area Treatment Device

The Stormwater Management StormFilter3
            using Perlite Filter Media
                        Prepared by:
                      NSF International
                  Ann Arbor, Michigan 48105
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
                        August 2005

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         THE ENVIRONMENTAL TECHNOLOGY VERIFICATION
                                      PROGRAM
   U.S. Environmental Protection Agency
                                                  NSF International
                     ETV Joint Verification Statement
    TECHNOLOGY TYPE:
    APPLICATION:

    TECHNOLOGY NAME:

    TEST LOCATION:
    COMPANY:
    ADDRESS:

    WEB SITE:
    EMAIL:
        STORMWATER TREATMENT TECHNOLOGY
        SUSPENDED SOLIDS AND ROADWAY POLLUTANT
        TREATMENT
        THE STORMWATER MANAGEMENT STORMFILTER®
        USING PERLITE FILTER MEDIA
        GRIFFIN, GEORGIA
        STORMWATER MANAGEMENT, INC.
        12021-B NE Airport Way
        Portland, Oregon 97220
        http://www.stormwaterinc.com
        mail@stormwaterinc.com
PHONE:  (800)548-4667
FAX:  (503)240-9553
NSF International (NSF), in cooperation with the U.S. Environmental Protection Agency (EPA), operates
the Water Quality Protection Center (WQPC), one of six centers under the Environmental Technology
Verification  (ETV) Program. The  WQPC recently evaluated the  performance of the Stormwater
Management  StormFilter®  (StormFilter),  with  perlite  filter media,  manufactured  by Stormwater
Management, Inc. (SMI). The StormFilter was installed in a city-owned right-of-way near downtown
Griffin, Georgia. Paragon Consulting Group (PCG) performed the testing.

EPA created the  ETV Program to facilitate the deployment of innovative  or improved environmental
technologies through performance verification and dissemination of information. The goal of the ETV
program is to further environmental protection by accelerating the acceptance and use of improved and
more cost-effective technologies. ETV seeks to  achieve this goal by providing high quality, peer-
reviewed data on technology performance to those involved in the design,  distribution, permitting,
purchase, and use of environmental technologies.
ETV works in partnership with recognized standards and testing organizations; stakeholder groups, which
consist of buyers, vendor  organizations, and permitters; and with the full participation of individual
technology developers. The program evaluates the performance of innovative technologies by developing
test plans that are responsive to the  needs of stakeholders, conducting field  or laboratory  tests  (as
appropriate), collecting and analyzing data, and preparing peer-reviewed reports. All evaluations  are
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.
05/23/WQPC-WWF
The accompanying notice is an integral part of this verification statement.

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                  August 2005

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TECHNOLOGY DESCRIPTION
The following description of the StormFilter was provided by the vendor and does not represent verified
information.
The StormFilter consists of an inlet bay, flow spreader, cartridge bay, overflow baffle, and outlet bay,
housed in an 18-ft long by  8-ft wide pre-cast concrete vault. The inlet bay serves as a grit chamber and
provides for flow transition into the cartridge bay. The flow spreader traps floatables,  oil, and  surface
scum. This StormFilter was designed to treat storm water at a maximum flow rate of 495 gpm (1.1 cfs).
Flows greater than the maximum flow rate would  overflow a baffle between the cartridge bay  and the
outlet bay, bypassing the filter media.
The StormFilter contains filter cartridges that contain media designed to  remove specific pollutants. In
this test, the cartridges were filled with perlite filter media, which traps particulates and adsorbs materials
such as petroleum hydrocarbons, suspended  solids, and  pollutants  such as nutrients and metals that
commonly bind to sediment particles. Water in the cartridge bay infiltrates  the filter media to a tube in the
center of the filter cartridge. When the center tube fills, a float valve opens and a check valve on top of
the filter cartridge closes, creating a siphon that draws water through the filter media. The filtered water
drains into a manifold under the filter cartridges and to the outlet bay, where it exits the system through
the discharge pipe. The system resets  when the cartridge  bay is drained  and the siphon is broken. Air
pulled into the filters when the siphon breaks helps to scrub solids from the filter, cleaning the filters and
preventing the filter cartridges from clogging.
The vendor claims that the treatment system can remove 50% to  90% of  the  suspended solids in
stormwater,  as well as 25% to 60% of total phosphorus, depending on site  characteristics, pollutant
loading, and sediment particle size. The vendor's claims are outlined in greater detail in the verification
report.
VERIFICATION TESTING DESCRIPTION
Methods and Procedures

The test methods and  procedures used during  the study are described in the Environmental Technology
Verification  Test Plan For The  Stormwater Management StormFilter,  TEA-21 Project Area,  City of
Griffin, Spalding County, Georgia, (June 2003). The City of Griffin requires that all storm drain systems
be designed to pass peak flows from a 25-yr event without causing surface flooding. For the StormFilter
drainage basin, a 25-yr storm event would have a 1.47-min time of concentration and would  generate a
peak runoff of 4.93 cfs. The rational method was used to calculate the peak flows to the system.
Verification testing consisted of collecting data during a minimum  of 15 qualified events that met the
following criteria:

    •   The total rainfall depth for the event, measured at the site, was 0.2 in. (5 mm) or greater;
    •   Flow through the treatment device was successfully measured and recorded over the duration of
       the runoff period;
    •   A flow-proportional composite  sample was successfully collected for both the influent  and
       effluent over the duration of the runoff event;
    •   Each composite sample was comprised of a minimum of five aliquots, including at least two
       aliquots on the rising limb of the runoff hydrograph, at least one aliquot near the peak, and at least
       two aliquots on the falling limb of the runoff hydrograph; and
    •   There was a minimum of six hours between qualified sampling events.
Automated sample monitoring and collection devices were installed and programmed to collect composite
samples from the influent and effluent during qualified flow events. In addition to the flow and analytical
data, operation and maintenance (O&M) data were recorded. Samples were analyzed for the following
parameters:

05/23/WQPC-WWF      The accompanying notice is an integral part of this verification statement.          August 2005
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Sediments                             Metals                 Nutrients
•   total suspended solids (TSS)         •  total and dissolved   •   total and dissolved phosphorus
•   suspended sediment concentration       cadmium, lead,      •   total Kjeldahl nitrogen (TKN)
    (SSC)                                copper and zinc      •   total nitrate
•   particle size distribution                                    •   total nitrite

The test plan included total petroleum hydrocarbon (TPH) and polynuclear aromatic hydrocarbon (PAH)
analyses in the suite of analytical parameters.  Samples were  initially analyzed for TPH and PAH along
with the sediment, metals, and nutrient parameters. TPH and PAH concentrations were below detection
limits for every  event.   In  December 2003,  SMI, NSF,  PCG,  and EPA  agreed  to eliminate the
hydrocarbon analyses from the sampling plan since these analyses were always below detection limits.
VERIFICATION OF PERFORMANCE
The following is a summary of the verified data gathered  during the course of verification testing.
Verification testing of the StormFilter lasted approximately 11 months. A significant number  of storm
events that met the qualification criteria were not sampled due to issues with the automated sampling
equipment and power supply, including blown fuses, power surges and interruptions, or sample tube
clogging. A total of 15 storm events were successfully sampled.
Test Results
The precipitation data for the  rain events are summarized in Table 1. The  peak flow rates exceeded the
StormFilter's rated flow capacity  during  several events,  indicating the  likelihood that some bypass
occurred during storm events with peak flows exceeding the StormFilter's rated flow capacity.

Table 1. Rainfall Data Summary
Event
number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Start
date
7/21/03
7/22/03
7/23/03
8/1/03
8/6/03
1/17/04
2/2/04
4/12/04
4/30/04
5/12/04
5/18/04
6/14/04
6/25/04
6/27/04
6/28/04
Start
time
18:30
15:00
17:40
16:25
14:40
21:15
10:35
19:30
18:05
17:10
15:10
11:35
13:10
18:25
22:40
Rainfall
amount
(in.)
0.49
0.22
0.33
1.73
0.76
0.44
0.33
0.31
0.74
0.52
1.24
0.43
0.46
0.82
0.59
Rainfall
duration
(hnmin)
0:40
0:55
1:05
4:15
1:30
4:40
8:10
0:35
6:40
2:00
0:50
0:35
6:20
2:45
1:35
Peak
Discharge
Rate (gal)1
362
398
572
1,040
881
175
21.7
778
296
431
879
838
282
959
975
Runoff
volume
(gpm)1
7,730
7,090
8,650
38,200
18,400
10,700
2,910
10,000
14,100
10,400
25,600
9,180
6,270
22,600
16,900
             1. Runoff volume and peak discharge rate measured at the outlet of the StormFilter.
                See the verification report for further details.
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The  monitoring results were  evaluated using event mean  concentration (EMC), or efficiency ratio
comparison, and sum  of loads  (SOL)  comparisons.  The EMC  evaluates treatment efficiency on a
percentage basis by dividing the effluent concentration by the influent concentration and multiplying the
quotient by 100. The EMC was calculated for each analytical parameter and each individual storm event.
The  SOL comparison evaluates the treatment efficiency on a percentage basis by comparing the sum of
the influent and effluent loads (the parameter concentration multiplied by the precipitation volume) for all
storm events. The calculation is made by subtracting from one the quotient of the total effluent load
divided by the total influent load, and multiplying by 100. SOL results can be summarized on an overall
basis since the loading  calculation takes into account both the concentration and volume of runoff from
each event. The analytical data ranges, EMC range, and SOL reduction values are shown in Table 2.

Table 2.  Analytical Data, EMC Range, and SOL Reduction Results
Parameter
TSS
ssc
Total phosphorus
Dissolved phosphorus
TKN
Total nitrate
Total nitrite
Total cadmium
Total copper
Total lead
Total zinc
Dissolved cadmium
Dissolved copper
Dissolved lead
Dissolved zinc
Units
mg/L
mg/L
mg/L as P
mg/L as P
mg/L as N
mg/L as N
mg/L as N
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
Inlet
Range
90-410
120-430
0.13-0.38
<0.02 - 0.23
O.4-2.5
0.37- 1.1
<0.01-0.04
<0.0005- 0.001
<0.004-0.02
0.02-0.07
0.07-0.23
<0.0005 - <0.0005
<0.004- 0.008
<0.005 - 0.02
0.02-0.14
Outlet
Range
12-110
55-200
0.05-0.19
<0.02 - 0.07
<0.4- 1.3
0.27- 1.9
<0.01-0.03
<0.0005-<0.0005
O.004-0.02
0.009-0.04
0.04-0.10
<0.0005 - <0.0005
<0.004 - 0.006
<0.005 - 0.02
0.01-0.10
EMC SOL
Range Reduction
(%) (%)
24-69
20-61
11-68
0-96
0-67
-170-30
0-75
50-75
0-65
0-67
30-67
ND
0-67
-50 - 75
-67 - 75
50
50
50
42
24
-13
36
70
34
37
52
ND
-44
-3.5
21
  ND: Not determined.

Based  on the SOL evaluation method, TSS, SSC and total  phosphorus reductions met the  vendor's
performance claim. The StormFilter was also able to remove some nutrients, total metals, and dissolved
zinc.
A particle size distribution procedure known as "sand-silt split" was conducted on samples as part of the
SSC analysis. The  sand-silt split procedure quantifies the percentage (by weight) of particles greater than
62.5 (im (defined  as sand) and less than 62.5  (im (defined as silt). The percentage of silt in the inlet
ranged from 73% to 99%, while the percentage of silt in the outlet ranged from 97% to 99%. This data
was incorporated into the SOL calculation, revealing the reduction in the SSC sand fraction was 95% and
the reduction in the SSC silt fraction was 42%.
System Operation
The StormFilter was installed by a subcontractor, under the supervision of PCG.  No issues were noted
during the installation.
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The StormFilter was cleaned in February 2003, and inspected in August 2003, January 2004, May 2004,
and December 2004.  During the December 2004 inspection, the filter chamber contained sediment at
depths ranging from one to four inches.  The filters were covered in sediment and organic detritus, but
appeared not to be clogged. A composite sample of the sediment was collected and analyzed for Toxicity
Characteristic Leachate Procedure metals, and the sediment was found to be non-hazardous.

Quality Assurance/Quality Control

NSF personnel completed a technical systems  audit during testing  to ensure that the testing was in
compliance with the test plan. NSF also completed a data quality audit of at least  10% of the test data to
ensure that the reported data represented the data generated during testing.  In addition to QA/QC audits
performed by NSF, EPA personnel conducted an audit of NSF's QA Management Program.
Original signed by:                                   Original signed by:
Sally Gutierrez	10/3/05	       Robert Ferguson	10/5/05
Sally Gutierrez                    Date              Robert Ferguson                   Date
Director                                             Vice President
National Risk Management Research Laboratory        Water Systems
Office of Research and Development                   NSF International
United States Environmental Protection Agency
    NOTICE:  Verifications  are  based on  an  evaluation  of technology  performance under  specific,
    predetermined criteria and the appropriate quality assurance procedures. EPA and NSF make no expressed
    or implied warranties as to the performance of the technology and do not certify that a technology will
    always operate as verified. The end user is solely responsible for complying with any and all applicable
    federal, state, and local requirements. Mention of corporate names, trade names, or commercial products
    does not constitute endorsement or recommendation for use of specific products. This report is not an NSF
    Certification of the specific product mentioned herein.
        Availability of Supporting Documents
        Copies of the ETV Verification Protocol, Stormwater Source Area Treatment Technologies Draft
        4.1, March 2002, the verification statement, and the verification report (NSF Report Number
        05/23/WQPC-WWF) are available from:
            ETV Water Quality Protection Center Program Manager (hard copy)
            NSF International
            P.O. Box 130140
            Ann Arbor, Michigan 48113-0140
        NSF website: http://www.nsf.org/etv (electronic copy)
        EPA website: http://www.epa.gov/etv (electronic copy)
        Appendices are not included in the verification report, but are available from NSF upon request.
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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 (WQPC),  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. Mention of trade names or commercial products does not constitute endorsement or
recommendation by the EPA for use or certification by NSF.

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                                      Foreword

The  following is the final report  on an Environmental  Technology Verification (ETV) test
performed for NSF International (NSF) and the United States Environmental Protection Agency
(EPA). The verification test for the  Stormwater Management, Inc. StormFilter® using Perlite
filter media was conducted at a testing site in Griffin, Georgia, maintained by the City of Griffin
Public Works and Stormwater Department.

The  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.
                                           11

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                                       Contents

Verification Statement	VS-i
Notice	i
Foreword	ii
Contents	iii
Figures	iv
Tables	v
Abbreviations and Acronyms	vi
Chapter 1 Introduction	1
  1.1   ETV Purpose and Program Operation	1
  1.2   Testing Participants and Responsibilities	1
            1.2.1  U.S. Environmental Protection Agency	2
            1.2.2  Verification Organization	2
            1.2.3  Testing Organization	3
            1.2.4  Analytical Laboratories	4
            1.2.5  Vendor	4
            1.2.6  Verification Testing Site	5
Chapter 2 Technology Description	6
  2.1   Treatment System Description	6
  2.2   Filtration Process	6
           2.2.1  StormGate	8
  2.3   Technology Application and Limitations	9
  2.4   Operations and Maintenance	9
  2.5   Performance Claim	10
           2.5.1  TSS	10
           2.5.2  Metals	11
           2.5.3  Nutrients	11
           2.5.4  Oil and Grease	11
Chapter 3 Test Site Description	12
  3.1   Location and Land Use	12
  3.2   Contaminant Sources and Site Maintenance	12
  3.3   Stormwater Conveyance System and Receiving Water	14
  3.4   Rainfall and Peak Flow Calculations	14
  3.5   StormFilter Installation	16
Chapter 4 Sampling Procedures and Analytical Methods	17
  4.1   Sampling Locations	17
           4.1.1  Upstream	17
           4.1.2  Influent	17
           4.1.3  Effluent	17
           4.1.4  Rain Gauge	17
  4.2   Monitoring Equipment	17
  4.3   Constituents Analyzed	18
  4.4   Sampling Schedule	18
  4.5   Field Procedures for  Sample Handling and Preservation	19
Chapter 5 Monitoring Results  and Discussion	20
  5.1   Storm Event Data	20
                                           in

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           5.1.1   Flow Data Evaluation	20
  5.2   Monitoring Results: Performance Parameters	23
           5.2.1   Concentration Efficiency Ratio	23
           5.2.2   Sum of Loads	28
  5.3   Particle Size Distribution	33
  5.4   TCLP Analysis	34
Chapter 6 QA/QC Results and Summary	35
  6.1   Laboratory/Analytical Data QA/QC	35
           6.1.1   Bias (Field Blanks)	35
           6.1.2   Replicates (Precision)	35
           6.1.3   Accuracy	36
           6.1.4   Representativeness	39
           6.1.5   Completeness	39
Chapter 7 Operations and Maintenance Activities	41
  7.1   System Operation and Maintenance	41
Chapter 8 References	42
Appendices	43
  A  StormFilter Design and O&M Guidelines	43
  B  Verification Test Plan	43
  C  Event Hydrographs and Rain Distribution	43
  D  Analytical Data Reports with QC	43
                                        Figures

Figure 2-1. Schematic drawing of atypical StormFilter system	7
Figure 2-2. Schematic drawing of a StormFilter cartridge	8
Figure 2-3. Schematic of the StormGate	9
Figure 3-1. As-built drawing for the StormFilter installation	13
Figure 3-2. Drainage basin map for the StormFilter installation	14
                                           IV

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                                       Tables

Table 4-1. Constituent List for Water Quality Monitoring	18
Table 5-1. Summary of Events Monitored for Verification Testing	21
Table 5-2. Peak Discharge Rate and Runoff Volume Summary	22
Table 5-3. Monitoring Results and Efficiency Ratios for Sediment Parameters	24
Table 5-4. Monitoring Results and Efficiency Ratios for Nutrients	25
Table 5-5. Monitoring Results and Efficiency Ratios for Total Metals	26
Table 5-6. Monitoring Results and Efficiency Ratios for Dissolved Metals	27
Table 5-7. Sediment Sum of Loads Results	29
Table 5-8. Nutrients Sum of Loads Results	30
Table 5-9. Total Metals Sum of Loads Results	31
Table 5-10. Dissolved Metals Sum of Loads Results	32
Table 5-11. Particle Size Distribution Analysis Results	33
Table 5-12. TCLP Results for Cleanout Solids	34
Table 6-1. Field Blank Analytical Data Summary	36
Table 6-2. Field Duplicate Sample Relative Percent Difference Data Summary	37
Table 6-3. Laboratory Duplicate Sample Relative Percent Difference Data Summary	38
Table 6-4. Laboratory MS/MSD RPD Data Summary	38
Table 6-5. Laboratory MS/MSD Data Summary	38
Table 6-6. Laboratory Control Sample Data Summary	39

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                          Abbreviations and Acronyms
AST
BMP
cfs
DTU
EMC
EPA
ETV
ft2
ft3
g
gal
gpm
HOPE
hr
in
kg
L
Ib
NRMRL
mg/L
min
mm
NSF
O&M
PCG
QA
QC
SMI
SOL
SOP
TCLP
TO
um
USGS
VO
WQPC
yd3
yr
Analytical Services, Inc.
best management practice
Cubic feet per second
Data transfer unit
Event mean concentration
U.S. Environmental Protection Agency
Environmental Technology Verification
Square feet
Cubic feet
Gram
Gallon
Gallon per minute
High density polyethylene
Hour
Inch
Kilogram
Liter
Pound
National Risk Management Research Laboratory
Milligram per liter
Minute
Millimeter
NSF International, formerly known as National Sanitation Foundation
Operations and maintenance
Paragon Consulting Group
Quality assurance
Quality control
Stormwater Management, Inc. (vendor)
Sum of the loads
Standard Operating Procedure
Toxicity Characteristic Leachate Procedure
Testing Organization (Paragon Consulting Group)
Micron
United States Geological Survey
Verification Organization (NSF)
Water Quality Protection Center
Cubic yard
Year
                                         VI

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                                      Chapter 1
                                     Introduction

1.1    ETV Purpose and Program Operation

The U.S. Environmental Protection  Agency (EPA) has created the Environmental Technology
Verification  (ETV)  Program  to   facilitate  the  deployment  of  innovative  or   improved
environmental technologies through  performance verification and dissemination of information.
The goal of the ETV program is to further environmental protection by substantially accelerating
the acceptance and use of improved and more cost-effective technologies. ETV seeks to achieve
this goal by providing high quality, peer reviewed data on technology performance to those
involved in the design, distribution, permitting, purchase, and use of environmental technologies.

ETV works in partnership with recognized standards and testing organizations; stakeholder
groups, which  consist of  buyers, vendor  organizations,  and permitters; and  with the  full
participation of individual technology developers. The program evaluates the performance of
innovative technologies by developing test plans that are responsive to the needs of stakeholders,
conducting field  or  laboratory (as  appropriate)  testing,  collecting  and analyzing  data,  and
preparing peer reviewed reports. All evaluations are conducted  in  accordance  with rigorous
quality assurance protocols to ensure that data of known and adequate quality are generated and
that the results are defensible.

NSF International (NSF), in cooperation with the EPA, operates the Water Quality Protection
Center (WQPC).  The  WQPC  evaluated the performance of the  Stormwater Management
StormFilter® using perlite filter media (StormFilter), a Stormwater treatment device designed to
remove sediments and pollutants from wet weather runoff.

It is important to  note that verification of the equipment does not mean that the equipment is
"certified"  by NSF or "accepted" by EPA. Rather, it recognizes that the performance of the
equipment has been determined and verified by these organizations for those conditions tested by
the Testing Organization (TO).

1.2    Testing Participants and Responsibilities

The ETV testing of the StormFilter was a cooperative effort among the following participants:

•  U.S. Environmental Protection Agency
•  NSF International
•  Paragon Consulting Group, Inc. (PCG)
•  Analytical Services, Inc. (ASI)
•  United States Geological Survey (USGS) Sediment Laboratory
•  Stormwater Management, Inc. (SMI)

The following is a brief description of each ETV participant and their roles and responsibilities.

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1.2.1    U.S. Environmental Protection Agency

The EPA Office of Research and Development, through the Urban Watershed Branch, Water
Supply  and Water Resources Division,  National Risk Management  Research  Laboratory
(NRMRL), provides administrative, technical, and quality assurance guidance and oversight on
all ETV Water Quality Protection Center activities. In addition, EPA provides financial support
for operation of the WQPC and partial support for the cost of testing for this verification. EPA's
responsibilities include:

•  Review and approval of the test plan;
•  Review and approval of verification report;
•  Review and approval of verification statement; and
•  Post verification report and statement on the EPA website.

The key EPA contact for this program is:

       Mr. Ray Frederick,          ETV WQPC Project Officer
       (732) 321-6627             email: Frederick.Ray@epamail.epa.gov

       U.S. EPA, NRMRL
       Urban Watershed Management Research Laboratory
       2890 Woodbridge Avenue (MS-104)
       Edison, New Jersey 08837-3679

1.2.2   Verification Organization

NSF is the verification organization (VO) administering  the WQPC in partnership with EPA.
NSF is a not-for-profit testing and certification organization dedicated to public health, safety,
and protection of the environment. Founded in 1946 and located in Ann Arbor, Michigan, NSF
has been instrumental in development of consensus standards for the protection of public health
and the environment. NSF also provides testing and certification services to ensure that products
bearing the NSF name, logo and/or mark meet those standards.

NSF personnel provided technical oversight of the verification process. NSF provided review of
the test plan and was  responsible  for the preparation of the verification report. NSF contracted
with Scherger Associates to provide  technical advice and to assist  with preparation of the
verification report. NSF's responsibilities as the VO include:

•  Review and comment on the test plan;
•  Review quality systems of all parties involved with the TO, and qualify the TO;
•  Oversee TO activities related to the technology evaluation and associated laboratory testing;
•  Conduct an on-site audit of test procedures;
•  Provide quality assurance/quality control (QA/QC) review and support for the TO;
•  Oversee the development of the verification report and verification statement; and,
•  Coordinate with EPA to approve the verification report and verification statement.

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Key contacts at NSF are:

       Mr. Thomas Stevens, P.E.,         Program Manager
       (734) 769-5347                   email: stevenst@nsf.org

       Mr. Patrick Davison,               Project Coordinator
       (734)913-5719                   email: davison@nsf.org

       NSF International
       789 North Dixboro Road
       Ann Arbor, Michigan 48105

       Mr. Dale A. Scherger, P.E.,         Technical Consultant
       (734)213-8150                   email: daleres@aol.com

       Scherger Associates
       3017 Rumsey Drive
       Ann Arbor, Michigan 48105

1.2.3   Testing Organization

The TO  for the verification  testing was Paragon Consulting Group, Inc.  (PCG)  of Griffin,
Georgia.  The TO was responsible for ensuring that the testing location and conditions allowed
for the verification testing to meet its stated objectives. The TO prepared the test plan; oversaw
the testing; and managed the data generated by the testing. TO employees set test conditions, and
measured and recorded data  during  the testing.  The TO's  Project Manager provided project
oversight.

PCG had primary responsibility for all verification testing, including:

•   Coordinate all testing and observations of the StormFilter in accordance with the test plan;
•   Contract with the  analytical laboratory, contractors and any other subcontractors necessary
    for implementation of the test plan;
•   Provide needed logistical support to subcontractors, as well as establishing a communication
    network, and scheduling and coordinating the activities for the verification testing; and
•   Manage data generated during the verification testing.

The key contact for the TO is:

       Ms. Courtney Nolan, P.E.,         Project Manager
       (770) 412-7700                   email: cnolan@pcgeng.com

       Paragon Consulting Group
       118 North Expressway
       Griffin, Georgia 30223

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1.2.4  Analytical Laboratories

Analytical Services, Inc. (AST), located in Norcross, Georgia,  analyzed the samples collected
during the verification test.

The key AST contact is:

       Ms. Christin Ford
       (770) 734-4200             email: cford@ASI.com

       Analytical Services, Inc.
       110 Technology Parkway
       Norcross, Georgia 30092

USGS Kentucky District Sediment Laboratory analyzed the suspended sediment concentration
(SSC) samples.

The key USGS laboratory contact is:

       Ms. Elizabeth A. Shreve,     Laboratory Chief
       (502)493-1916             email: eashreve@usgs.gov

       United States Geological Survey, Water Resources Division
       Northeastern Region, Kentucky District Sediment Laboratory
       9818 Bluegrass Parkway
       Louisville, Kentucky 40299

1.2.5  Vendor

Stormwater Management,  Inc. of Portland, Oregon is the vendor  of the StormFilter,  and was
responsible for supplying a field-ready system. Vendor responsibilities include:

   •   Provide the technology and ancillary equipment required for the verification testing;
   •   Provide technical  support  during  the installation and  operation of  the  technology,
       including the  designation of a representative to ensure the technology is functioning as
       intended;
   •   Provide descriptive details about the capabilities and intended function of the technology;
   •   Review and approve the test plan; and
   •   Review and comment on the draft verification report and draft verification statement.

The key contact for SMI is:

       Mr. James Lenhart, P.E.,     Senior Vice President
       (800) 548-5667             email: iiml@stormwaterinc.com

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       Storm water Management, Inc.
       12021-BNE Airport Way
       Portland, Oregon 97220

1.2.6   Verification Testing Site

The StormFilter was located within right-of-way on the west side of Fifth Street in Griffin,
Georgia. The key contact for City of Griffin Public Works and Stormwater Department is:

       Mr. Brant Keller Ph.D.,     Director
       (770)229-6424             email: bkeller@citvofgriffm.com

       Public Works and Stormwater Department
       City of Griffin
       134 North Hill Street
       Griffin, Georgia 30224

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                                      Chapter 2
                               Technology Description

The following technology description was supplied by the vendor and does not represent verified
information.

2.1    Treatment System Description

The components installed at this testing site included a StormFilter and a StormGate™ high flow
bypass structure (StormGate). The  StormGate was  installed upstream  of the StormFilter and
included a field-adjustable weir, which was set to divert continuous flows up to 495 gpm
(1.1 cfs)  to the StormFilter.  Continuous  flows greater  than 495  gpm would  bypass the
StormFilter at the StormGate and discharge to the overflow pipe that reconnected with the storm
sewer  system downstream of the StormFilter. The performance  of the StormGate was not
included as part of this verification. Additional technical information on the StormGate is
provided in Section 2.2.1.

The StormFilter is designed to remove sediments, metals, and other roadway pollutants from
stormwater. The StormFilter  under test was designed  to treat storm water with  a maximum
continuous flow rate of 495 gpm. Flows entering the StormFilter  that exceeded the design flow
rate would bypass the filter cartridges via the high-flow  bypass weir in the StormFilter. The unit
consisted of an energy dissipater, cartridge bay, flow spreader, high-flow bypass weir, and outlet
bay, all housed in a 18-ft long by 8-ft wide pre-cast  concrete vault.  The flow spreader provided
for the trapping  of floatables, oil, and surface scum. The unit also included 33 filter cartridges
filled  with perlite  filter media, installed  inline with the storm drain lines. The cartridge bay
provided for sediment storage capacity of 1.9 yd3. A  schematic of the StormFilter and a detail of
the filter cartridge are shown in Figures 2-1 and 2-2.

Additional equipment specifications, test site  descriptions,   testing  requirements,  sampling
procedures, and analytical methods were detailed in  the Environmental Technology Verification
Test Plan for the Stormwater Management StormFilter*, TEA 21 Project Area, City of Griffin,
Spalding County, Georgia June, 2003. The test plan is included in Appendix B.

2.2    Filtration Process

The filtration process works by percolating storm water through a  series of filter cartridges filled
with perlite filter media, which traps particulates and pollutants  such as phosphorus,  nitrogen,
and metals that commonly  bind to sediment particles.  The  perlite  media  can  also  adsorb
materials such as petroleum hydrocarbons  and dissolved constituents present in the stormwater.
A diagram identifying the filter cartridge components is shown in Figure 2-2.

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                                  ACCESS DOORS
    LAUOtH
  FLOW SPREADER
  OUTLET PIPE
                                                                              FLOW SPREADER
                                                                                  INLET PIPE
        DISCHARGE
         HIGH FLOW BYPASS
                                                                           ENERGY DISSIPATOR
J
                              StormFilter CARTRIDGE
                                                         FILTRATION BAY
Figure 2-1. Schematic drawing of a typical StormFilter system.
Stormwater enters the cartridge bay  through the flow  spreader, where it  ponds.  Air in the
cartridge is displaced by the water and purged from beneath the filter hood through the one-way
check valve located on top of the cap. The water infiltrates through the filter media and into the
center tube. Once the center tube fills with water, a float valve opens and the water in the center
tube flows into the under-drain manifold, located beneath the filter cartridge. This causes the
check valve to close,  initiating a siphon that draws Stormwater through the filter. The siphon
continues until  the water surface elevation drops to the elevation  of the hood's  scrubbing
regulators. When the siphon begins to break air is quickly drawn beneath the hood,  causing high-
energy turbulence  between the inner surface  of the hood and the outer surface of the filter.  This
turbulence agitates the surface of the  filter, releasing accumulated sediments on the  surface,
flushing them from beneath the hood, and allowing them to settle to the vault floor. This  surface-
cleaning mechanism maintains the permeability of the filter surface and enhances the overall
performance and longevity of the system. When the water drains, the float valve closes and the
system resets.

The StormFilter is equipped with an internal  overflow baffle  designed to  bypass flows and
prevent catch basin backup  and surface flooding. The bypass flow is  discharged through the
outlet pipe along with the treated water.

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2.2.1   StormGate
The StormGate is a system installed upstream of the StormFilter. It is designed to bypass high-
energy flows that exceed a treatment system's design capacity. The StormGate is provided as a
complete manhole or vault unit that installs directly into an existing sewer system. A schematic
of a typical StormGate is shown in Figure 2-3.
                                                         CKECK VALVE
                                                               FLOAT
              FILTER MEDIA
               CENTER TUBE
                  FLOAT SEAT
        SCRUBBING REGULATORS
          UNDER-DRSN MANIFOLD
                                                                     HOOD
                                                                     OUTER SCREEN
                                                                     OPTIONAL SECONDARY
                                                                     FILTER MEDIA
                           FILTERED WftTER
                                         UNDER-DRSIN MANIFOLD .
                                         CAST INTO VAULT FLOOR
VAULT FLOOR
Figure 2-2. Schematic drawing of a StormFilter cartridge.
High flows can reduce the effectiveness of water quality facilities by resuspending sediments and
flushing captured floatables,  which  causes  a concentrated pulse of pollutants to be  sent  to
downstream waterways. To  minimize  the occurrence of pulsing, a high-flow  bypass  can be
installed upstream of water quality or pretreatment facilities to direct the high flow away from
the treatment system. The StormGate uses a field-adjustable weir to direct polluted low flows to
stormwater  treatment systems, while  allowing extreme flows  to  bypass the  systems.  The
StormGate provides tighter control over system hydraulics than other high-flow bypass methods,
as changes can be made to the weir  elevation once actual field elevations  are established or if
future design flows change.

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                   STEPS
                                                                  HIGH FLOW OUTLET PIPE
                                                               FiELD-ADJUSTABLE WEIR
                                                        LOW FLOW OUTLET PIPE
                              STORMGATE HIGH FLOW BYPASS
Figure 2-3. Schematic of the StormGate.
2.3    Technology Application and Limitations

The StormFilter is being used to treat stormwater runoff in a wide variety of sites throughout the
United States. The StormFilter typically requires 2.3 ft of head differential between the inlet and
outlet.

The StormFilter may be used for development, roadways, and specialized applications. Typical
development applications include parking lots, commercial and industrial sites, and high-density
and  single-family  housing. Typical development applications  also  include  maintenance,
transportation and port facilities.  Typical  roadway applications include arterial roads,  freeways,
bridge decks,  and light rail and transit facilities. For specialized  applications,  laboratory
evaluation of the water is normally required to establish the operational parameters.

2.4    Operations and Maintenance

The StormFilter requires minimal  routine maintenance.  SMI recommends that the system be
maintained once per year. The rate at which the system collects pollutants will depend more on
site activities than the size of the unit.

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SMI recommends that the StormFilter device be inspected between six to nine months following
the previous maintenance or original installation, generally late in the rainy season.  Maintenance
typically includes cartridge replacement or exchange and should take place during dry weather
conditions. Maintenance may also involve  disposal of materials that require consideration of
regulatory guidelines.

It is important to check the condition of the StormFilter following major storm events to check
for damage caused by high flows and to check for high sediment accumulation, which may be
caused by localized erosion  in the drainage area. It may be necessary to adjust maintenance
activity scheduling depending on the actual operating conditions encountered by the system.

During inspection, loose debris and trash can be removed using a pole with a grapple or net on
the end if system performance appears to be hindered.  Cleanout of the StormFilter is  best
accomplished with the use of mobile vactor equipment. Approximately three to four inches of
sediment on the  vault  floor warrants full cleaning  of the StormFilter.  The cartridges are
completely plugged if they remain  submerged  after an extended  time  during  dry weather
conditions. However, the inspector should insure that the cartridges  are not submerged due to
backwater conditions caused by high groundwater, plugged pipes, or high hydraulic grade lines.
Completely plugged cartridges can also be  associated  with heavy oil and  grease loading from
animal and vegetable fats or petroleum hydrocarbons, which warrants source control measures.

The media should be replaced when the white perlite media becomes darkened to the point of
almost being  black.  A square  nose shovel or  vacuum  truck should  be used to remove
accumulated sediments after cartridge removal.

It is important to note that the drainage structures  and  system upstream of the treatment device
should also be maintained to ensure maximum function of the SMI devices.

2.5    Performance Claim

According to SMI, the performance of the StormFilter varies with regards  to pollutant loading,
variability in contaminate concentrations, environmental conditions, regional soil variation, flow
rate through the cartridge, and media type.  As  flow  rate is decreased through the cartridge,
performance typically increases at removal of TSS, nutrients, and metals.

2.5.1   TSS

SMI expected the StormFilter to achieve a net removal efficiency ranging between 50% to 90%
depending upon the site characteristics and pollutant loading.  TSS removal performance  is
expected to increase with increases in the loading of sand. As TSS becomes finer, performance
will decrease.  TSS concentrations less than 40 mg/L have presented difficulties in quantifying
performance.

   1.  Laboratory  experiments have  indicated that a single StormFilter cartridge operating  at
       15 gpm using a coarse perlite media achieves TSS removal efficiency of 79% with a 95%
                                           10

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       confidence limit of 78% and 80%, respectively, for a sandy loam material comprised of
       55% sand, 45% silt, and 5% clay (USDA) by mass, using simulated stormwater.

   2.  Laboratory experiments have indicated that a single StormFilter cartridge operating at 15
       gpm using a coarse perlite media achieves TSS removal efficiency of 77% with a 95%
       confidence  limit of 76  and 77%, respectively, for  a manufactured  SIL-CO-SIL 106
       material comprised  of 20% sand  and 80%  silt  (USDA) by  mass, using simulated
       stormwater.

   3.  Field  and laboratory experiments have indicated that a single  StormFilter cartridge
       operating at 15 gpm using CSF leaf media had a TSS removal  efficiency of 73% with
       95% confidence limits of 68% and 79%,  respectively.

2.5.2  Metals

Metals are measured  as both total  metals and soluble metals.  Total metals are the sum of
dissolved metals and those metals associated with particulates.  Soluble metals are commonly
defined as those metals that  pass through a 0.45-|im filter.  Frequently, the  soluble metals are
cationic form in that they posses a net positive charge.

Typically, performance claims are given for dissolved metals because total metals are associated
with particulate matter that is difficult to quantify.  For removal of dissolved metals via  cation
exchange, SMI recommends use of the zeolite or CSF® media.

At this time, no performance claims for the removal of metals can  be made for perlite. Metals
removal will be tied closely to site conditions and the removal of TSS.

2.5.3  Nutrients

Nutrients are typically removed via attachment to sediment particles.  CSF leaf media  is not
recommended for the removal of soluble phosphorus or nitrogen. Nutrients maybe removed by
perlite and perlite mixtures (perlite/zeolite/granular activated carbon) and are recommended for
nutrient sensitive waters.

Total phosphorus reduction claims are not usually provided using CSF leaf media due to its
organic nature. Perlite and perlite mixtures are capable of removing between 25% and 60% total
phosphorus.

2.5.4  Oil and Grease

The  system performs best when oil and grease loadings are less than 25 mg/L with measured
removal rates between 40% to 70%. Oil  and grease concentrations that exceed 15 mg/L on a
consistent basis  may  need  to  incorporate additional  oil  and grease control measures to aid
removal and protect media longevity.
                                           11

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                                      Chapter 3
                                Test Site Description
3.1    Location and Land Use
The StormFilter is located within the City of Griffin right-of-way, along the eastern side of Fifth
Street, just north of the southeast corner of the intersection of Fifth Street and Taylor Street at
33° 14' 51.5040" latitude and  84° 15'  37.4040" longitude.  These coordinates are based on
Arcview's Global Information System (GIS) utilizing state plane coordinates.

Figure 3-1  is an  as-built drawing of the StormFilter and adjacent features, while Figure 3-2
identifies the drainage basin, the location of the  unit,  and the surface contours of the drainage
basin. The drainage basin consists of approximately 0.7 acres. An estimated 85% of the drainage
basin is impervious and includes about 45 linear feet of storm sewer pipe and one storm inlet. No
detention areas or open ditches are located within  the drainage basin. No open ditches are located
upstream of the StormFilter installation location.

The majority of the  drainage basin consists  of paved roadways, parking areas and various retail
and commercial buildings. An unpaved church parking lot within the drainage basin provided a
considerable sediment contribution to the stormwater. Small portions of the drainage basin are
either landscaped sections or are lawns. Moderate to heavy traffic volume runs along Taylor
Street, but  no major storage or use of hazardous materials or chemicals exists in the drainage
basin. None of the stormwater runoff from the drainage basin was pretreated prior to entering the
StormFilter.

The nearest receiving water is Grape Creek, which is located approximately two-thirds of a mile
east of the  StormFilter. All water,  either treated or bypass, flows via pipe flow in an easterly
direction approximately 800 ft through storm pipe and ultimately flows into Grape Creek.

Griffin  has many  local ordinances to aid  in  stormwater  management improvement  and
implement pollution control measures.  Such ordinances include establishment of the Stormwater
Utility, Soil Erosion and Sediment Control, buffer width,  and land disturbance requirements.
Copies of the existing ordinances are included in Attachment E of the test plan.

3.2    Contaminant Sources and Site Maintenance

The main pollutant  sources  within  the  drainage  basin are created by vehicular traffic, typical
urban commercial land use, and atmospheric  deposition. Trash and debris accumulate on the
surface and enter the stormwater system through large  openings in the street inlets, sized to
accommodate the large storm flows that can occur in this  part of Georgia. The storm sewer catch
basins do not have  sumps.  There are no other stormwater best  management practices (BMPs)
within the drainage basin.
                                           12

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                                      O I   DWCB A-1
                                           TOP 941.25
                                           INV OUT 930.96
                                           INV IN 932,01
                                        5  INV IN 931.06 LINE B
                                        rn
                                         JB B-1
                                       PJTOP  942.54
                                         INV 932,05
               JB B-2
               TOP  945.63
               INV OUT 934.44
               INV IN  938.21
               (STORM FILTER) (o
               INV OUT 934,43
               JB B-3
               TOP 947.16
               INV IN 941.49
               INV OUT 941.46
               (STORM FILTER)
               INV OUT 935.10
                               oo
                   JB B-4
                   TOP  949,42
                   INV 942,64(0
   CONCRETE
   PAD STORM FILTER
       TOP 946.94
       INV OUT 938.82
—TOP MH  947,20
   OCONCRETE
     PAR
  __^	 TOP 947.3S
                                                       STORM FILTER
               INV IN 940.62
       -JB C-1
       TOP 947.75
       INV IN 941.49
       INV OUT 941.27
                                      CONCRETE
                                      PAD

                                       -STORM FILTER
                                        STORM GATE ELEV, 942,49
                                   10 SWCB B-5
                                      TOP 950,35
                                      INV  943.32
                          GRAPHIC  SCALE
                               (  IN FEET )
                             1  inch. = SO  ft
Figure 3-1. As-built drawing for the StormFilter installation.
                                        13

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  I^J
Figure 3-2. Drainage basin map for the StormFilter installation.

No planned or on-going maintenance activities are in place for the area of the installation, such
as street sweeping or catch basin cleaning. Because Taylor Street  is a  State Highway, the
Georgia Department of Transportation is responsible for maintenance activities along the road.
According  to Griffin Public Works Department personnel, if such activities were performed,
Griffin would either be involved with the actions,  or at least informed that the  activities are to
take place.  Such maintenance activities are typically only performed during emergencies.

3.3    Stormwater Conveyance System and Receiving Water

As previously  discussed,  the  nearest receiving  water  is  Grape  Creek,  which is  located
approximately two-thirds of a mile east of the  StormFilter unit.  All water, either treated or
bypass, flows via pipe flow in an easterly direction approximately 800 ft through storm pipe and
ultimately flows into Grape Creek.

3.4    Rainfall and Peak Flow  Calculations

The rainfall amounts for the one-,  two-, ten-, and twenty-five year storms for the drainage area
are presented in Table 3-1. The  protocol  specifies  that  a  value  for the  6-month storm be
presented, however, these data were not available. Table 3-2 presents the intensities in inches per
                                            14

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hour calculated for the given rainfall depths. These data were utilized to generate the peak flows
shown in Table 3-3.  Table 3-4 presents the peak flow calculated using the time of concentration
for the drainage basin.

Griffin requires that all  storm  drain systems be designed to accommodate the 25-yr storm.  A
1.47-min time of concentration was  determined for  the basin,  generating  a  peak runoff of
4.93 cfs for the 25-yr storm event. The rational method was used to calculate the peak flows for
the StormFilter. The rationale for these calculations was discussed in the test plan.


Table 3-1. Rainfall Depth (in.)


            Duration	1-yr	2-yr	10-yr	25-yr
30 min
Ihr
2hr
12 hr
24 hr
0.99
1.36
1.68
2.67
2.87
1.19
1.61
2.00
3.12
3.36
1.58
2.10
2.62
3.96
4.32
1.81
2.40
2.98
4.44
4.80
           Source: NOAA,2000


Table 3-2. Intensities (in./hr)


             Duration     1-yr	2-yr	10-yr	25-yr
30 min
Ihr
2hr
12 hr
24 hr
1.99
1.36
0.84
0.22
0.12
2.38
1.61
1.00
0.26
0.14
3.16
2.10
1.31
0.33
0.18
3.61
2.40
1.49
0.37
0.20
Table 3-3. Peak Flow Calculations (cfs)

             Duration     1-yr	2-yr	10-yr	25-yr
30 min
Ihr
2hr
12 hr
24 hr
1.26
0.86
0.53
0.14
0.08
1.51
1.02
0.64
0.17
0.09
2.01
1.33
0.83
0.21
0.11
2.29
1.52
0.95
0.23
0.13
Table 3-4. Peak Flow Calculations (cfs) Using Time of Concentration

             Duration     1-year	2-year	10-year	25-year
             30 min       2.71	3.19	4.31	4.93
                                           15

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3.5    StormFilter Installation

The construction  contractor utilized to  complete the construction work associated with the
installation of the StormFilter device was determined by bid. Site Engineering, Inc. of Atlanta,
Georgia  was the  selected contractor. Installation  activities began in  April, 2002.  Installation
consisted of installing  the  StormFilter  and  StormGate  into  the existing  storm  sewer
infrastructure. The StormFilter and StormGate were delivered and installed in May, 2002. SMI
personnel were  at the  site  during installation  to  ensure  that  the  device  was installed
correctly. Construction activities were completed in July, 2002.
                                             16

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                                      Chapter 4
                  Sampling Procedures and Analytical Methods

Descriptions  of the sampling  locations and  methods  used during verification testing are
summarized in this section. The test plan presents the details on the approach used to verify the
StormFilter. An overview of the key procedures used for this verification is presented below.

4.1    Sampling Locations

Three locations in the test site storm sewer system were selected  as sampling and monitoring
sites to determine the treatment capability of the StormFilter.

4.1.1   Upstream

This monitoring site was  selected  to  monitor the stormwater flow  rates entering  into the
StormGate.  A  velocity/stage  meter was  located  in the  influent pipe,  upstream  from the
StormGate, so that  potential  backwater effects of the treatment device would not affect the
velocity measurements. The upstream monitoring location was selected only to evaluate flow
conditions, and did not include the ability to collect samples.

4.1.2   Influent

This sampling and monitoring site was selected to characterize the untreated stormwater diverted
to the StormFilter by the StormGate. A velocity/stage meter and sampler suction tubing were
located in the influent pipe, upstream from the StormFilter.

4.1.3   Effluent

This sampling and  monitoring site was selected to characterize the  stormwater exiting the
StormFilter. A velocity/stage meter and sampler  suction tubing,  connected to the automated
sampling equipment, were located in the pipe downstream from the StormFilter.

4.1.4  Rain Gauge

A rain gauge was located  adjacent to the drainage area to monitor the depth  of precipitation from
storm events. The data were used to  characterize the  events  to determine if they met the
requirements for a qualified storm event.

4.2    Monitoring Equipment

The specific equipment used for monitoring flow, sampling water quality, and measuring rainfall
for the upstream and downstream monitoring points is listed below:

   •   Sampler: American Sigma 900MAX automatic sampler with a data transfer unit (DTU II)
       data logger;
                                           17

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    •   Sample Containers: Two 1.9-L glass and six polyethylene bottles; or one four-gallon
       polyethylene container;
    •   Flow Monitors: American Sigma Area/Velocity Flow Monitors; and
    •   Rain Gauge: American Sigma Tipping Bucket Model 2149.

4.3    Constituents Analyzed

The list of constituents analyzed in the stormwater samples is shown in Table 4-1.


Table 4-1. Constituent List for Water Quality Monitoring
Parameter
Total suspended solids (TSS)
Suspended sediment
concentration (SSC)
Total phosphorus
Dissolved phosphorus
Total Kjeldahl nitrogen (TKN)
Nitrate + nitrite nitrogen
Total zinc
Total lead
Total copper
Total cadmium
Dissolved zinc
Dissolved lead
Dissolved copper
Dissolved cadmium
Sand-silt split
Reporting
Units
mg/L
mg/L
mg/L as P
mg/L as P
mg/L as N
mg/L as N
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
ug/L
NA
Method
Detection
Limit
5
0.5
0.016
0.02
0.10
0.02
4
5
4
0.07
4
5
4
0.07
NA
Method1
EPA 160.2
ASTMD3977-97
EPA 365.1
SM 4500P B,E
EPA 35 1.3
EPA 9056
EPA 200.7
EPA 200.7
EPA 200.7
EPA 7131
EPA 200.7
EPA 200.7
EPA 200.7
EPA 7131
Fishman et al
          1  EPA: EPA Methods and Guidance for the Analysis of Water procedures; ASTM:
           American Society of Testing and Materials procedures; SM: Standard Methods for the
           Examination of Water and Wastewater; Fishman et al.: Approved Inorganic and Organic
           Methods for the Analysis of Water and Fluvial Sediment procedures; NA: Not applicable.

4.4    Sampling Schedule

The monitoring equipment was installed in August 2002. From September 2002 through June
2003, several trial events were monitored and the equipment tested and calibrated. Verification
testing began in July 2003, and ended in June 2004. As defined in the test plan, "qualified" storm
events met the following requirements:
                                            18

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    1.  The total rainfall depth for the event, measured at the site rain gauge, was 0.2 in. (5 mm)
       or greater.

    2.  Flow through the treatment device was  successfully measured and recorded over the
       duration of the runoff period.

    3.  A flow-proportional composite sample was successfully collected for both the influent
       and effluent over the duration of the runoff event.

    4.  Each composite sample collected was  comprised of  a  minimum  of five aliquots,
       including at least two aliquots on the rising limb of the runoff hydrograph, at least one
       aliquot near the peak, and at least two aliquots on the falling limb.

    5.  There was  a minimum of six hours between qualified sampling events.

4.5    Field Procedures for Sample Handling and Preservation

Water  samples were  collected with Sigma automatic samplers programmed to collect aliquots
during each sample cycle.  A peristaltic pump on the sampler pumped water from the sampling
location through Teflon™-lined sample tubing to the pump head  where water passed through
silicone tubing  and into the sample  collection  bottles.  After  qualified events, samples were
removed from the sampler, split and capped by PCG personnel.  Samples were preserved per
method requirements and analyzed within the holding times allowed by the methods, except as
noted in Chapter 6. Samples for particle size and SSC  determination were shipped to the USGS
sediment laboratory. All  other samples  were  shipped to  AST  for analysis. Custody  was
maintained according to the laboratory's sample handling procedures. To establish the necessary
documentation to trace sample possession from the time of collection, field forms and lab forms
(see Attachment G of the test plan) were completed and accompanied each sample.

The test plan included sampling and analysis for oil and grease (total petroleum hydrocarbons
and  polynuclear  aromatic  hydrocarbons). For  events  sampled before December  2003,  the
autosampling equipment was programmed to  place the  first two  aliquots in the glass  sample
containers,  and  to composite the subsequent aliquots in the polyethylene sample containers. In
December 2003, the  TO,  VO, vendor, and EPA agreed  to discontinue oil and grease analyses
after all analytical data reported no detectable hydrocarbon concentrations. When this  change
was made, the TO changed to the single four-gallon polyethylene sample container, and a sample
splitting procedure that included vigorously stirring the sample with a  stirring rod attached to a
drill, and pouring off directly into the sample containers shipped to the laboratories.
                                          19

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                                      Chapter 5
                        Monitoring Results and Discussion

Precipitation and stormwater flow records were evaluated to verify that the storm events met the
qualified event requirements.  The qualified event data is  summarized in  this chapter. The
monitoring results related to contaminant reduction over the events are reported in two formats:

       1.  Efficiency ratio comparison, which evaluates the effectiveness of the system on an
          event mean concentration (EMC) basis.

       2.  Sum of loads (SOL) comparison, which evaluates the effectiveness of the system on a
          constituent mass (concentration times volume) basis.

5.1    Storm Event Data

Table 5-1 summarizes  the storm data for the qualified events.  Detailed information on each
storm's runoff hydrograph and the rain depth distribution over the event period are included in
Appendix C. The sample collection starting times for the inlet and outlet samples, as well as the
number of sample aliquots collected,  varied from event to event. The samplers were activated
when the respective velocity meters sensed flow in the pipes, and the depth had reached 0.5 in.
providing sufficient depth for a sample to be collected.

5.1.1   Flow Data Evaluation

With perfect measurements,  the inlet and outlet volumes should be exactly  the same, and the
upstream volume should also be the same so long as the StormGate did not allow high flows to
bypass the StormFilter.  Table 5-2 summarizes the flow volumes and peak discharge rates for the
three monitoring locations for  each of the qualified events. A sizable difference was observed
between the inlet, outlet and upstream flow volumes during most storm events. According to the
flow monitor  manufacturer, area velocity sensors  work best  when  installed  in  sites with
normalized flow, free of turbulence caused by obstructions, vertical drops, or pipe bends. When
practical, sensors should be installed at a minimum distance of five times the maximum expected
level upstream from an obstruction  and ten  times  the  expected  level downstream from  an
obstruction. The flow monitors were calibrated at irregular intervals throughout the course of the
study and consistently produced data with discrepancies as noted below.

Upstream: The upstream flow monitoring location  provided data on the total  flow entering into
the StormGate. The flow monitor was installed in  an  18-in. high-density polyethylene (HDPE)
pipe  upstream of the StormGate. This pipe had a  straight run of approximately  30  ft with an
average slope of approximately 3.8%, and the sensor was installed in a location free  of
obstructions. The upstream flow monitor failed to record data during events 7 and  8, and the
depth probe  readings were biased approximately two inches high during events  9 and  13, but
appeared to function properly during the other qualified events. In general, the upstream volume
data was similar to the outlet volume data and higher than the inlet volume data.
                                          20

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Table 5-1. Summary of Events Monitored for Verification Testing
Event
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Start
Date
7/21/03
7/22/03
7/23/03
8/1/03
8/6/04
1/17/04
2/2/04
4/12/04
4/30/04
5/12/04
5/18/04
6/14/04
6/25/04
6/27/04
6/28/04
Start
Time
18:30
15:00
17:40
16:25
14:40
21:15
10:35
19:30
18:05
17:10
15:10
11:35
13:10
18:25
22:40
End
Date
7/21/03
7/22/03
7/23/03
7/31/03
8/6/03
1/18/04
2/2/04
4/12/04
4/30/04
5/12/04
5/18/04
6/14/04
6/25/04
6/27/04
6/29/04
End
Time
19:10
15:55
18:45
20:40
16:10
1:55
18:45
20:05
0:45
19:10
16:00
12:10
19:40
21:10
0:15
Rainfall
Amount
(in)
0.49
0.22
0.33
1.73
0.76
0.44
0.33
0.31
0.74
0.52
1.24
0.43
0.46
0.82
0.59
Rainfall
Duration
(hnmin)
0:40
0:55
1:05
4:15
1:30
4:40
8:10
0:35
6:40
2:00
0:50
0:35
6:20
2:45
1:35
The upstream peak runoff intensity was generally higher than the inlet peak runoff intensity and
lower than the outlet peak runoff intensity. The upstream flow monitor's water elevation data
were also used to evaluate whether the water elevation exceeded the StormGate weir elevation
with respect to the invert  elevation of the pipe where flow was monitored (approximately
10.5 in.), which would indicate a bypass condition. Events 1, 4  and  11 had inlet peak runoff
intensities greater than the design flow of the StormFilter (495 gpm). During these events, the
peak water level  elevation at the  upstream monitoring location reached  6.1 in., 8.1  in, and
10.2 in., respectively. Due to turbulence and a possibility of slight water elevation measurement
inaccuracies, it is likely that some bypass occurred at the StormGate during these events.
                                           21

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Table 5-2. Peak Discharge Rate and Runoff Volume Summary


                     Rainfall Peak runoff intensity (gpm)      Flow volume (gal)
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Date
7/21/03
7/22/03
7/23/03
7/31/03
8/7/03
1/17/04
2/2/04
4/13/04
4/30/04
5/12/04
5/18/04
6/14/04
6/25/04
6/27/04
6/28/04
(in)
0.49
0.22
0.33
1.84
0.76
0.44
0.33
0.31
0.74
0.52
1.24
0.43
0.46
0.82
0.59
Upstream
711
332
537
1,710
393
94.7
NR
NR
273
129
651
193
180
425
357
Inlet
349
103
304
515
347
49.5
68.6
191
120
293
591
155
110
342
233
Outlet
362
398
572
1,040
881
175
21.7
778
296
431
879
838
282
959
975
Upstream
7,020
5,390
5,770
27,100
8,120
5,710
NR
NR
18,200
7,280
18,500
6,270
16,500
17,100
12,700
Inlet
3,860
1,610
2,230
12,400
5,810
2,610
1,100
2,510
3,850
5,130
17,000
2,190
2,100
5,840
4,500
Outlet
7,730
7,090
8,650
38,200
18,400
10,700
2,910
10,000
14,100
10,400
25,600
9,180
6,270
22,600
16,900
Inlet: The inlet flow monitoring location provided data on the flow diverted from the StormGate
and entering the StormFilter. The flow monitor was installed in an 8-in. pipe that ran from the
StormGate to junction  box JB  C-l (refer to  Figure  3-1). This pipe  had a straight run of
approximately 10 ft with an average slope of approximately -0.3%. This pipe was sized to handle
an maximum flow rate (without head) approximately equivalent to the 495-gpm design flow of
the StormFilter.  The  short pipe run  prevented  sensor installation  in  a location free  of
obstructions. The inlet flow and peak runoff intensity data were consistently lower than both the
upstream and outlet data. This flow probe was used primarily to activate the inlet autosampler,
rather than to accurately gauge the volume and intensity of the flow. The inlet autosampler was
programmed to collect aliquots at intervals lower than the downstream sampler to account for the
lower recorded water volume. During event 11,  the depth probe read a depth of 50 in., which is
likely attributable to a  probe malfunction, possibly under full-pipe conditions, but appeared to
function consistently during the other events.

Outlet:  The outlet flow monitoring location provided data on the flow exiting the  StormFilter.
The flow monitor was installed in an 8-in. pipe that ran from the StormFilter to junction box JB
B-2 (refer to Figure 3-1). This pipe had a straight run of approximately 8 ft with an average slope
of approximately 7.6%. The short pipe run prevented  sensor installation in a location free of
obstructions. However, the StormFilter's outlet bay is designed to minimize turbulence, so it is
likely that the flow in this pipe was sufficiently quiescent for  flow monitoring. The outlet flow
data were similar to the upstream flow data and higher than the inlet flow data. The outlet peak
runoff intensity  data were generally higher than both  the inlet  and upstream data. This may
indicate that either the StormFilter can treat water in excess of its design capacity, or water was
                                           22

-------
bypassing filtration by flowing over the weir located between the filter chamber and outlet
chamber.

Conclusion: The inlet monitoring location was not a valid monitoring point for accurately
measuring flow. The flow volume data from the upstream and outlet monitoring locations were
generally similar, and differences were attributable either to the StormFilter treating water in
excess of its rated  capacity,  water bypassing the  StormFilter cartridges by flowing over the
internal weir between the cartridge chamber and outlet chamber, or flow measurement error. The
upstream monitor experienced two events where no data were collected and two events where
the depth readings were biased high, but reliable data for the other events. Therefore, the outlet
volume data appear to be more reliable than the inlet volume data for sum of loads calculations.

5.2    Monitoring Results: Performance Parameters

5.2.1   Concentration Efficiency Ratio

The concentration efficiency ratio reflects the  treatment capability of the device using the event
mean concentration (EMC) data obtained for each runoff event. The concentration efficiency
ratios are calculated by:

                     Efficiency ratio = 100 x (l-[EMCeffluent/EMCinflUent])               (5-2)

The influent and effluent sample concentrations and calculated efficiency ratios  are summarized
by analytical parameter categories:  sediments (TSS  and SSC), nutrients (total phosphorus, TKN,
nitrates, and nitrites), and total and dissolved metals (cadmium, copper, lead, and zinc).

Sediments: The inlet and outlet  sample concentrations  and  calculated  efficiency ratios for
sediments are  summarized in Table 5-3.  The TSS  inlet concentrations ranged  from 90 to 410
mg/L, the outlet concentrations ranged from  36 to 150 mg/L, and the efficiency ratio ranged
from  24%  to  69%.  The SSC inlet  concentrations  ranged  110 to 430 mg/L, the  outlet
concentrations ranged from 55 to 200 mg/L,  and the efficiency ratio ranged from  20% to 61%.

The results show a similarity between inlet TSS and SSC concentrations. Both the TSS and SSC
analytical  parameters measure sediment concentrations in water; however, the TSS analytical
procedure requires the analyst to draw an  aliquot from the sample container, while the SSC
procedure requires use of the entire contents of the sample container. If a sample contains a high
concentration of settleable (large particle size  or high density) solids, acquiring  a representative
aliquot from the sample container is very difficult. Therefore a disproportionate amount of the
settled solids may be left in the container, and the  reported TSS concentration  would be lower
than SSC.  Since this phenomenon was not  observed during this study, it appears  that the
sediment loading consisted primarily  of sediments with  small particle size. This observation
correlates with the particle size distribution data summarized in Section 5.3.
                                           23

-------
Table 5-3. Monitoring Results and Efficiency Ratios for Sediment Parameters
Event
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Date
7/21/03
7/22/03
7/23/03
8/1/03
8/6/03
1/17/04
2/2/04
4/12/04
4/30/04
5/12/04
5/18/04
6/14/04
6/25/04
6/27/04
6/28/04
Inlet
(mg/L)
90
98
170
160
230
96
120
270
170
99
410
130
180
130
120J
TSS
Outlet
(mg/L)
44
74
90
75
120
38
36
150
72
56
150
74
110
100
84J
Reduction
(%)
51
24
47
53
48
60
69
43
57
43
64
43
37
25
28
Inlet
(mg/L)
130
120
230
220
280
120
NA
340
180
180
430
160
170
110
160
ssc
Outlet
(mg/L)
77
78
130
99
160
55
NA
200
77
78
170
99
87
90
87
Reduction
(%)
41
33
42
55
43
53
NA
42
57
57
61
40
47
20
47
          NA: Not analyzed due to insufficient collected sample volume.
          J: Estimated concentration, samples analyzed one day outside hold time.

Nutrients: The inlet  and outlet sample concentrations and  calculated efficiency ratios are
summarized in Table 5-4. Total phosphorus inlet concentrations ranged from 0.13 to 0.38 mg/L
(as P), and the EMC reduction ranged from 11% to 85%. Dissolved phosphorus concentrations
were near or below the method detection limits. TKN inlet concentrations ranged from <0.4 to
2.5 mg/L (as N),  and the EMC  reduction ranged  from 0%  to  67%.  Total  nitrate  inlet
concentrations ranged from 0.21 to  1.14 mg/L (as N), and the EMC ranged from -170% to 33%.
Total nitrite inlet and outlet concentrations were near or below method detection limits.

Metals: The data for inlet and  outlet sample concentrations and calculated efficiency ratios for
total metals are in Table 5-5, and dissolved metals are in Table 5-6. Total and dissolved cadmium
inlet and outlet concentrations were near or below the method detection limits. Total  copper inlet
concentrations ranged from <0.004 to 0.02 mg/L,  and the EMC reduction ranged from 0% to
65%. Dissolved  copper inlet concentrations ranged from <0.004 to 0.008 mg/L, and the EMC
reduction ranged from 0% to  67%. Total lead inlet concentrations ranged from 0.02 to 0.07
mg/L,  and the EMC  reduction ranged from 0% to 75%. Dissolved lead inlet concentrations
ranged from <0.005 to 0.02 mg/L, and the EMC reduction ranged from -50% to 75%. Total zinc
inlet concentrations ranged from 0.07 to 0.23 mg/L, and the EMC reduction ranged from 30% to
70%. Dissolved zinc inlet concentrations ranged from 0.02 to 0.14 mg/L, and the EMC reduction
ranged from -67% to 75%.
                                          24

-------
Table 5-4. Monitoring Results and Efficiency Ratios for Nutrients
Event
No. Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
7/21/03
7/22/03
7/23/03
8/1/03
8/6/04
1/17/04
2/2/04
4/12/04
4/30/04
5/12/04
5/18/04
6/14/04
6/25/04
6/27/04
6/28/04
Inlet
(mg/L)
0.14
0.13
0.18
0.38
0.23
0.34
0.27
0.30
0.22
0.18
0.30
0.26
0.19
0.18
0.13
Outlet Reduction Inlet
(mg/L) (%) (mg/L)
0.08
0.11
0.16
0.12
0.16
0.05
0.23
0.19
0.08
0.11
0.19
0.15
0.09
0.09
0.11
43
15
11
68
30
85
15
37
64
39
37
42
53
50
15
O.02
0.04
O.02
O.02
O.02
0.23
0.06
0.08
0.03
0.02
0.05
0.04
0.07
0.06
0.02
Outlet Reduction Inlet
(mg/L) (%) (mg/L)
O.02
0.01
O.02
0.02
O.02
0.01
0.04
0.07
0.01
0.02
0.05
0.03
0.04
0.04
0.02
ND
75
ND
ND
ND
96
33
13
67
ND
0
25
43
33
ND
0.4
0.4
O.4
O.4
1.2
1.7
1.2
2.5
0.6
1.5
1.8
0.7
1.5
0.9
1.0
Outlet
(mg/L)
0.2
0.2
O.4
O.4
0.9
1.3
0.9
1.5
0.2
1.2
1.4
0.5
1.3
0.8
1.0
Reduction Inlet
(%) (mg/L)
50
50
ND
ND
25
24
25
40
67
20
22
29
13
11
0
0.59
1.1
0.62
0.21
0.49
0.71
0.37
0.67
NA
0.51
0.73
0.93
NA
1.1
0.68
Outlet Reduction Inlet
(mg/L) (%) (mg/L)
0.65
0.80
0.59
0.27
0.50
0.50
0.56
0.48
NA
0.69
0.62
0.71
NA
0.76
1.9
-10
29
5
-29
-2
30
-51
28
NA
-35
15
24
NA
33
-170
0.03
0.03
0.02
O.01
0.02
0.01
0.03
0.03
NA
0.02
0.04
0.03
NA
0.01
0.01
Outlet Reduction
(mg/L) (%)
0.02
0.02
0.005
O.01
0.005
0.02
0.03
0.02
NA
0.02
0.02
0.02
NA
0.005
0.01
33
33
75
ND
75
ND
0
33
NA
0
50
33
NA
50
0
 NA: Not analyzed due to expiration of hold time.
 ND: Not determinable.
 Values in boldface text represent results where one-half the method detection limit was substituted for values below detection limits to calculate EMC.
                                                                       25

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Table 5-5. Monitoring Results and Efficiency Ratios for Total Metals
Event
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Total Cadmium
Inlet Outlet Reduction Inlet
(mg/L) (mg/L) (%) mg/L
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
0.0005
0.0006
<0.0005
<0.0005
<0.0005
0.0010
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
0.00025
0.00025
<0.0005
<0.0005
<0.0005
0.00025
<0.0005
<0.0005
<0.0005
<0.0005
ND
ND
ND
ND
ND
50
58
ND
ND
ND
75
ND
ND
ND
ND
0.02
0.01
0.02
0.01
0.01
0.01
0.01
0.02
0.01
0.02
0.02
0.004
0.01
0.009
<0.004
Total Copper
Outlet Reduction
mg/L (%)
0.007
0.007
0.009
0.01
0.009
0.007
0.007
0.01
0.006
0.02
0.009
0.002
0.008
0.005
<0.004
65
30
55
0
10
30
46
50
40
0
55
50
20
44
ND
Inlet
mg/L
0.02
0.04
0.04
0.03
0.05
0.02
0.03
0.05
0.03
0.03
0.07
0.03
0.03
0.03
0.03
Total Lead
Outlet Reduction Inlet
mg/L (%) mg/L
0.009
0.01
0.04
0.02
0.04
0.02
0.02
0.04
0.01
0.01
0.03
0.02
0.02
0.03
0.01
55
75
0
33
20
0
29
20
67
67
57
33
33
0
67
0.11
0.09
0.09
0.08
0.10
0.21
0.13
0.18
0.15
0.19
0.23
0.10
0.12
0.08
0.07
Total Zinc
Outlet Reduction
mg/L (%)
0.04
0.06
0.06
0.05
0.06
0.10
0.08
0.09
0.05
0.07
0.07
0.07
0.07
0.04
0.04
64
33
33
38
40
52
41
50
67
63
70
30
42
50
43
   ND: Not determinable.
   Values in boldface text represent results where one-half the method detection limit was substituted for values below detection limits to calculate EMC.
                                                                   26

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Table 5-6. Monitoring Results and Efficiency Ratios for Dissolved Metals
Event
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Dissolved Cadmium Dissolved Copper Dissolved Lead Dissolved Zinc
Inlet Outlet Reduction Inlet Outlet Reduction Inlet Outlet Reduction Inlet Outlet Reduction
mg/L mg/L (%) mg/L mg/L (%) mg/L mg/L (%) mg/L mg/L (%)
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
<0.0005
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
<0.004
<0.004
<0.004
<0.004
<0.004
0.006
0.007
0.008
<0.004
0.005
<0.004
<0.004
<0.004
<0.004
<0.004
0.006
0.006
<0.004
0.006
<0.004
0.002
0.005
0.006
<0.004
0.005
<0.004
<0.004
<0.004
<0.004
<0.004
ND
ND
ND
ND
ND
67
29
25
ND
0
ND
ND
ND
ND
ND
<0.005
<0.005
<0.005
<0.005
0.008
0.01
0.02
<0.005
<0.005
<0.005
0.01
0.008
<0.005
0.01
0.01
<0.005
<0.005
<0.005
<0.005
0.01
0.0025
0.009
<0.005
<0.005
<0.005
0.009
0.009
0.007
0.02
0.008
ND
ND
ND
ND
-25
75
55
ND
ND
ND
10
-13
ND
-50
20
0.04
0.03
0.02
0.02
0.03
0.14
0.11
0.05
0.06
0.06
0.03
0.09
0.13
0.06
0.03
0.01
0.05
0.02
0.02
0.03
0.04
0.09
0.03
0.03
0.04
0.04
0.10
0.09
0.05
0.04
75
-67
0
0
0
71
16
40
50
33
-33
-11
31
17
-33
   ND: Not determinable.
   Values in boldface text represent results where one-half the method detection limit was substituted for values below detection limits to calculate EMC.
                                                                   27

-------
5.2.2  Sum of Loads

The sum of loads (SOL) is the sum of the% load reduction efficiencies for all the events, and
provides a measure of the overall  performance efficiency for the  events sampled during the
monitoring period. The load reduction efficiency is calculated using the following equation:

                     % Load Reduction Efficiency = 100 x (1 - (A / B))                 (5-3)

       where:
       A = Sum of Effluent Load =  (Effluent EMCi)(Flow Volumei) +
       (Effluent EMC2)(Flow Volume2) + (Effluent EMCn)(Flow Volumen)

       B = Sum of Influent Load =  (Influent EMCi)(Flow Volumei) +
       (Effluent EMC2)(Flow Volume2) + (Effluent EMCn)( Flow Volumen)

       n= number of qualified sampling events

As noted in Section 5.1.1,  the outlet monitoring location provided the most representative flow
data, so the SOL calculation was made using the outlet volumes for both the inlet and outlet data.

Sediment: Table 5-7 summarizes results for the SOL calculations for TSS and SSC. The SOL
analyses indicate a 50% reduction for both TSS and SSC.

As noted in Section 5.1.1,  the outlet monitoring location provided the most representative flow
data, so the SOL calculation was made using the outlet volumes for both the inlet and outlet data.
As a point of comparison, if the inlet volume data were used to calculate the sediment SOL, the
result would  be a 54% reduction in TSS and a 53% reduction in SSC.  Similarly, calculating
sediment SOL using the upstream volume data results in a 50%  reduction in TSS and a 51%
reduction  in SSC. This demonstrates that using the different volumes had little impact on the
resulting SOL calculations. For this reason, the loads for metals and nutrients are calculated
using only the outlet volumes.

Nutrients: The SOL data for nutrients are summarized in Table 5-8. The total phosphorus load
was reduced by 50%, dissolved  phosphorous was reduced by 42%, nitrate was reduced by -13%,
TKN was reduced by 24%,  and nitrite was reduced by 36%. The  nitrate SOL reduction was
heavily influenced by  event 15. When this data point is removed,  the SOL reduction for nitrate
increases to 15%.

Metals: The SOL data for total and dissolved metals are summarized in Tables 5-9 and  5-10,
respectively. The total cadmium load was reduced by 70%, however, most influent and effluent
sample concentrations were near or below method detection limits. Total copper was reduced by
34%, total lead was reduced  by 37%, and total zinc was reduced by 52%. Dissolved cadmium
was not detected,  dissolved copper was reduced by -44% (although  most analytical data was
near or below the analytical detection limit), dissolved lead was reduced by -3.5%, and dissolved
zinc was reduced by 21%.
                                          28

-------
Table 5-7. Sediment Sum of Loads Results

Event
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15


Date
7/21/03
7/22/03
7/23/03
8/1/03
8/6/03
1/17/04
2/2/04
4/12/04
4/30/04
5/12/04
5/18/04
6/14/04
6/25/04
6/27/04
6/28/04
Runoff
Volume
(gal)
7,730
7,090
8,650
38,200
18,400
10,700
2,910
10,000
14,100
10,400
25,600
9,180
6,270
22,600
16,900
Sum of the Loads
Removal
Efficiency
(%)
TSS
Inlet
(Ib)
5.8
5.8
12
51
35
8.6
2.8
22
20
8.6
87
9.9
9.5
25
16J
320

Loading
Outlet
(Ib)
2.8
4.4
6.5
24
18
3.4
0.87
13
8.5
4.9
31
5.7
6.0
19
12J
160
50
SSC
Inlet
(Ib)
8.4
6.9
17
70
42
10
NA
28
21
16
92
13
8.6
21
23
380

Loading
Outlet
(Ib)
5.0
4.6
9.6
32
24
4.9
NA
16
9.1
6.8
36
7.6
4.5
17
12
190
50
             NA: Not analyzed due to insufficient collected sample volume.
             J: Estimated weight, TSS samples analyzed one day outside hold time.
                                             29

-------
Table 5-8. Nutrients Sum of Loads Results
Dissolved

Event
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15


Date
7/21/03
7/22/03
7/23/03
8/1/03
8/6/04
1/17/04
2/2/04
4/12/04
4/30/04
5/12/04
5/18/04
6/14/04
6/25/04
6/27/04
6/28/04
Runoff
Volume
(gal)
7,730
7,090
8,650
38,200
18,400
10,700
2,910
10,000
14,100
10,400
25,600
9,180
6,270
22,600
16,900
Sum of the Loads
Removal
Efficiency
(%)
Total Phosphorus
Inlet
(Ib)
0.009
0.008
0.013
0.12
0.035
0.030
0.007
0.025
0.026
0.016
0.064
0.020
0.010
0.034
0.018
0.44

Outlet
(Ib)
0.005
0.007
0.012
0.038
0.025
0.004
0.006
0.016
0.009
0.010
0.041
0.011
0.005
0.017
0.015
0.22
50
Phosphorus
Inlet
(Ib)
ND
0.002
ND
0.003
ND
0.021
0.001
0.006
0.004
ND
0.011
0.003
0.004
0.011
ND
0.066

Outlet
(Ib)
ND
0.001
ND
0.006
ND
0.001
0.001
0.006
0.001
ND
0.011
0.002
0.002
0.008
ND
0.038
42
TKN
Inlet
(Ib)
0.03
0.02
ND
ND
0.18
0.15
0.03
0.21
0.07
0.13
0.38
0.08
0.08
0.17
0.14
1.6

Outlet
(Ib)
0.01
0.01
ND
ND
0.14
0.12
0.02
0.13
0.02
0.10
0.30
0.04
0.07
0.15
0.14
1.2
24
Total Nitrate
Inlet
(Ib)
0.038
0.066
ND
0.067
ND
0.063
0.009
0.056
NA
0.044
ND
ND
NA
0.21
0.096
0.65

Outlet
(Ib)
0.042
0.047
ND
0.086
ND
0.045
0.014
0.040
NA
0.060
ND
ND
NA
0.14
0.26
0.74
-13
Total Nitrite
Inlet
(Ib)
0.0019
0.0018
0.0014
ND
0.0031
0.0004
0.0007
0.0025
NA
0.0017
0.0085
0.0023
NA
0.0019
0.0014
0.028

Outlet
(Ib)
0.0013
0.0012
0.0004
ND
0.0008
0.0018
0.0007
0.0017
NA
0.0017
0.0043
0.0015
NA
0.0009
0.0014
0.018
36
        NA: Not analyzed due to expiration of hold time.
        ND: Not determined because both inlet and outlet samples were below detection limits.
        Values in boldface text represent results where one-half the method detection limit was substituted for values below detection limits to
        calculate SOL reduction.
                                                                    30

-------
Table 5-9. Total Metals Sum of Loads Results

Event
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15


Date
7/21/03
7/22/03
7/23/03
8/1/03
8/6/04
1/17/04
2/2/04
4/12/04
4/30/04
5/12/04
5/18/04
6/14/04
6/25/04
6/27/04
6/28/04
Runoff
Volume
(gal)
7,730
7,090
8,650
38,200
18,400
10,700
2,910
10,000
14,100
10,400
25,600
9,180
6,270
22,600
16,900
Sum of the Loads
Removal
Efficiency 1
(%)
Total
Inlet
(g)
ND
ND
ND
ND
ND
0.020
0.007
ND
ND
ND
0.097
ND
ND
ND
ND
0.12

Cadmium
Outlet
(g)
ND
ND
ND
ND
ND
0.010
0.003
ND
ND
ND
0.024
ND
ND
ND
ND
0.037
70
Total
Inlet
(g)
0.59
0.27
0.65
1.4
0.70
0.40
0.14
0.76
0.53
0.79
1.9
0.14
0.24
0.77
ND
9.4

Copper
Outlet
(g)
0.20
0.19
0.29
1.4
0.63
0.28
0.08
0.38
0.32
0.79
0.87
0.07
0.19
0.43
ND
6.2
34
Total
Inlet
(g)
0.59
1.1
1.3
4.3
3.5
0.81
0.31
1.9
1.6
1.2
6.8
1.0
0.71
2.1
1.8
29
Lead
Outlet
(g)
0.26
0.27
1.31
2.9
2.8
0.81
0.22
1.51
0.53
0.39
2.9
0.69
0.47
2.40
0.83
18
37
Total
Inlet
(g)
3.2
2.4
2.9
12
7.0
8.5
1.4
6.8
8.0
7.5
22
3.5
2.8
6.8
4.3
99
Zinc
Outlet
(g)
1.2
1.6
2.0
7.2
4.2
4.0
0.85
3.4
2.7
2.8
6.8
2.4
1.7
3.7
2.8
47
52
          ND: Not determined because both inlet and outlet samples were below detection limits.
          Values in boldface text represent results where one-half the method detection limit was substituted for values below detection limits to
          calculate SOL reduction.
                                                                    31

-------
Table 5-10. Dissolved Metals Sum of Loads Results

Event
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15


Date
7/21/03
7/22/03
7/23/03
8/1/03
8/6/04
1/17/04
2/2/04
4/12/04
4/30/04
5/12/04
5/18/04
6/14/04
6/25/04
6/27/04
6/28/04
Runoff
Volume
(gal)
7,730
7,090
8,650
38,200
18,400
10,700
2,900
10,000
14,100
10,400
25,600
9,180
6,270
22,600
16,900
Sum of the Loads
Removal
Efficiency (%)
Dissolved
Inlet
(g)
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
Cadmium
Outlet
(g)
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
Dissolved
Inlet
(g)
0.059
0.054
ND
0.29
ND
0.24
0.077
0.30
ND
0.20
ND
ND
ND
ND
ND
1.2
Copper
Outlet
(g)
0.18
0.16
ND
0.87
ND
0.081
0.055
0.23
ND
0.20
ND
ND
ND
ND
ND
1.8
-44
Dissolved
Inlet
(g)
ND
ND
ND
ND
0.56
0.40
0.22
ND
ND
ND
0.97
0.28
0.06
1.0
0.64
4.2
-3.5
Lead
Outlet
(g)
ND
ND
ND
ND
0.70
0.10
0.10
ND
ND
ND
0.87
0.31
0.17
1.5
0.51
4.3

Dissolved Zinc
Inlet
(g)
1.2
0.81
0.65
2.9
2.1
5.7
1.2
1.9
3.2
2.4
2.9
3.1
3.1
5.2
1.9
38

Outlet
(g)
0.29
1.3
0.65
2.9
2.1
1.6
1.0
1.1
1.6
1.6
3.9
3.5
2.1
3.9
2.6
30
21
           ND: Not determined because both inlet and outlet samples were below detection limits.
           Values in boldface text represent results where one-half the method detection limit was substituted for values below detection limits
           to calculate SOL reduction.
                                                                    32

-------
5.3    Particle Size Distribution

Particle size distribution analysis  was conducted as part of the SSC  analysis by the USGS
laboratory. The SSC method includes a "sand/silt split" analysis determined the percentage of
sediment (by weight) larger than 62.5 jim (defined as sand) and less than 62.5 jim (defined as
silt). The particle size distribution results are summarized in Table 5-11. The inlet samples had a
high proportion  of fine  sediment.  During  most  events,  the proportion of  larger particles
decreased during treatment, which indicates the StormFilter removed  a  higher proportion of
larger particles.

The SOL  can be recalculated for SSC concentrations and "sand/silt split" data to determine the
proportion of sand and silt removed during treatment. This evaluation shows that 95% of "sand"
and 42% of "silt" was removed.
Table 5-11. Particle Size Distribution Analysis Results
Sand (>62.5 um)    Silt (<62.5 um)
                                                               Sand SOL
Silt SOL
Event
No.1
1
2
3
4
5
6
8
9
10
11
12
13
14
15
Date
7/21/03
7/22/03
7/23/03
8/1/03
8/6/03
1/17/04
4/12/04
4/30/04
5/12/04
5/18/04
6/14/04
6/25/04
6/27/04
6/28/04
Volume
(gal)
7,730
7,090
8,650
38,200
18,400
5,710
10,000
14,100
10,400
25,600
9,180
6,270
22,600
16,900
Inlet
2.4
19.2
7.1
27.2
11.7
8.2
9.4
8.3
13.3
21.1
10.6
8.1
0.8
10.6
Outlet
1.1
1.1
0.7
2.3
0.7
1.2
0.9
2.3
1.5
1.7
1.0
4.1
1.8
3.1
Inlet
97.6
80.8
92.9
72.8
88.3
91.8
90.6
91.7
86.7
78.9
89.4
91.9
99.2
89.4
Outlet
98.9
99.0
99.3
97.7
99.3
98.8
99.1
97.7
98.5
98.3
99.0
95.9
98.2
96.9
Sum of the loads




Removal
Inlet
Ob)
0.20
1.33
1.18
19.0
4.94
0.45
2.64
1.77
2.09
19.5
1.33
0.70
0.19
2.45
58.1
efficiency (%)
Outlet
Ob)
0.06
0.05
0.07
0.73
0.17
0.03
0.15
0.21
0.10
0.62
0.08
0.19
0.31
0.38
3.15
95
Inlet
Ob)
8.17
5.59
15.4
50.8
37.4
5.07
25.5
19.5
13.6
72.7
11.2
7.93
24.1
20.7
319

Outlet
Ob)
4.91
4.56
9.53
30.8
23.8
2.59
16.2
8.84
6.66
35.7
7.50
4.36
16.7
11.9
186
42
1. Sand/silt split analysis not conducted for event 7 due to insufficient collected sample volume.
                                           33

-------
5.4    TCLP Analysis

At the end of the verification program, the StormFilter was evaluated to estimate the volume of
retained sediments in the filter chamber (see Chapter 7). A representative composite sample of
the sediments removed from the filter chamber was sent to the laboratory for TCLP metals
analysis. The results, shown in Table 5-12, indicate that any metals present in the solids were not
teachable and the sediment was not hazardous. Therefore, it could be disposed of in a standard
Subtitle D solid waste landfill or other appropriate disposal location.

Table 5-12. TCLP Results for Cleanout Solids

                                                          Regulatory Hazardous
    	Parameter	TCLP Result (mg/L)	Waste Limit (mg/L)
     Arsenic                             <0.2                      5.0
     Barium                             0.6                       100
     Cadmium                           <0.01                      1.0
     Chromium                          <0.01                      5.0
     Copper                            <0.02                      NA
     Lead                                <0.1                      5.0
     Mercury                           <0.002                     0.2
     Nickel                              <0.02                      NA
     Selenium	<0.2	LO	

    NA: Not applicable.
                                          34

-------
                                      Chapter 6
                           QA/QC Results and Summary

The Quality Assurance Project Plan (QAPP) in the test plan identified critical measurements and
established several  QA/QC  objectives.  The verification test procedures and  data  collection
followed the QAPP. QA/QC  summary results are reported in this section, and the full laboratory
QA/QC results and supporting documents are presented in Appendix D.

6.1    Laboratory/Analytical Data QA/QC

6.1.1   Bias (Field Blanks)

Field blanks were collected  at both the  inlet and outlet samplers  to evaluate the potential  for
sample  contamination through the automatic sampler, sample collection bottles,  splitters, and
filtering devices. The field blank  was collected on May 9, 2003,  allowing PCG to review  the
results early in the monitoring schedule.

Results for the field blanks are shown in Table 6-1. The data identified detectable concentrations
of TKN, total  zinc,  and dissolved zinc in the inlet  sample, and total and dissolved zinc in  the
outlet sample,  while other compounds were below  detection limits in both the  inlet and outlet
samples.

After  reviewing the analytical data, the  TO hypothesized that the TKN and zinc contribution
could have resulted  from incomplete rinsing of the sample containers. On July 25 and 30, 2003,
the TO repeated decontamination procedures and collected additional samples to analyze  for
those  constituents  identified during  the May sampling  event. The  data showed a residual
concentration of total zinc in the inlet blank sample. These results show that an acceptable level
of contaminant control in field procedures was achieved.

6.1.2   Replicates (Precision)

Precision measurements were performed by the collection and analysis of duplicate samples. The
relative% difference (RPD)  recorded from  the  sample analyses was  calculated to evaluate
precision. RPD is calculated using  the following formula:

                                                                                  (6-1)
                               %RPD =  | ^——H x 100%
                                            x

       where:
       AH =  Concentration of compound in sample
       x_i =  Concentration of compound in duplicate
       A! =  Mean value of AH and Ai2

The  RPD data show an acceptable  level field  of precision, with a few parameters outside
generally  accepted limits.  In  most  circumstances  where  the  RPD  values are high, the
concentrations were near or below method detection limits.
                                           35

-------
Table 6-1. Field Blank Analytical Data Summary
                                      April 23, 2003
July 25,2003    July 30, 2003
Parameter
Nitrite-nitrite nitrogen
Total phosphorus
TKN
TSS
Total cadmium
Total copper
Total lead
Total zinc
Dissolved cadmium
Dissolved copper
Dissolved lead
Dissolved zinc
Units
mg/L as N
mg/L as P
mg/L as N
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
Inlet
<0.1
<0.02
0.7
<5
<0.0005
<0.004
<0.005
0.08
<0.0005
<0.004
<0.005
0.06
Outlet
<0.1
<0.02
<0.4
<5
<0.0005
<0.004
<0.005
0.04
<0.0005
<0.004
<0.005
0.13
Inlet
NA
NA
<0.4
NA
NA
NA
NA
0.02
NA
NA
NA
NA
Outlet
NA
NA
0.5
NA
NA
NA
NA
<0.02
NA
NA
NA
NA
Inlet
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Outlet
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
<0.004
   NA: Not analyzed

Field precision: Field duplicates were collected to monitor the overall precision of the sample
collection procedures,  including  sample splitting.  Duplicate  inlet and outlet samples were
collected during three different storm events to evaluate precision in the sampling process  and
analysis. The duplicate samples were processed, delivered to the laboratory, and analyzed in the
same manner as the regular samples. Summaries of the field duplicate data are presented in
Table 6-2. The data show several sample pairs with a high RPD. For many of these samples, the
sample concentrations were near or below method detection limits, creating a condition where a
slight measurement deviation can cause a large RPD value.

Laboratory precision:  AST analyzed duplicate samples from aliquots drawn from the same
sample container as part of their QA/QC program. Summaries of the laboratory duplicate data
are presented in Table 6-3. The laboratory also analyzed the relative percent difference (RPD) on
matrix  spike/matrix spike duplicate (MS/MSD)  samples, summarized in Table 6-4.  The data
show that laboratory precision was generally maintained throughout the course of the project.

6.1.3 Accuracy

Method  accuracy  was  determined  and  monitored  using a  combination  of MS/MSD  and
laboratory control  samples  (known concentration  in blank  water). The  MS/MSD  data  are
evaluated by calculating the deviation from perfect recovery (100%), while laboratory control
data are  evaluated by calculating the absolute value of deviation from the laboratory control
concentration. Tables 6-5 and 6-6 summarize the  matrix spikes and  lab control sample recovery
data, respectively. The matrix spikes and lab control samples remained within targeted objectives
throughout the study, with the exception of two cadmium samples and one TSS sample.
                                           36

-------
   Table 6-2. Field Duplicate Sample Relative Percent Difference Data Summary
Analyte
TSS

Total nitrate

Total nitrite

TKN

Total phosphorus

Dissolved phosphorus

Total cadmium

Total copper

Total lead

Total zinc

Dissolved cadmium

Dissolved copper

Dissolved lead

Dissolved zinc

Units
mg/L

mg/L as N

mg/L as N

mg/L as N

mg/L as P

mg/L as P

mg/L

mg/L

mg/L

mg/L

mg/L

mg/L

mg/L

mg/L

Loc
inlet
outlet
inlet
outlet
inlet
outlet
inlet
outlet
inlet
outlet
inlet
outlet
inlet
outlet
inlet
outlet
inlet
outlet
inlet
outlet
inlet
outlet
inlet
outlet
inlet
outlet
inlet
outlet
Event 12
Rep 1 Rep 2
130
74
0.93
0.71
0.03
0.02
0.7
0.5
0.26
0.15
0.04
0.03
0.0005
O.0005
0.004
0.002
0.03
0.02
0.10
0.07
0.0005
0.0005
O.004
0.004
0.008
0.009
0.09
0.10
119
74
0.94
0.72
0.03
0.03
0.5
0.6
0.15
0.19
0.03
0.03
0.0005
O.0005
0.002
0.005
0.02
0.03
0.06
0.10
0.0005
0.0005
O.004
0.004
0.01
0.009
0.06
0.07
RPD
8.8
0
1.1
1.4
0
40
33
18
54
24
29
0
ND
ND
67
86
40
40
50
35
ND
ND
ND
ND
22
0
40
35
Event 13
Rep 1 Rep 2
182
114
NA
NA
NA
NA
1.5
1.3
0.19
0.09
0.07
0.04
0.0005
O.0005
0.01
0.008
0.03
0.02
0.12
0.07
0.0005
0.0005
O.004
0.004
0.0025
0.007
0.13
0.09
179
146
NA
NA
NA
NA
1.7
1.3
0.20
0.10
0.08
0.03
0.0005
O.0005
0.01
0.007
0.04
0.03
0.12
0.07
0.0005
0.0005
O.004
0.004
0.008
0.01
0.13
0.11
RPD
1.7
25
ND
ND
ND
ND
13
0
5.1
11
13
29
ND
ND
0
13
29
40
0
0
ND
ND
ND
ND
105
35
0
20
Event 14
Rep 1 Rep 2
133
100
1.14
0.76
0.01
O.01
0.9
0.8
0.18
0.09
0.06
0.04
0.0005
O.0005
0.009
0.005
0.025
0.028
0.080
0.043
0.0005
0.0005
O.004
0.002
0.012
0.018
0.061
0.046
120
92
1.13
0.76
0.02
O.01
1.7
1.0
0.09
0.16
0.03
0.03
0.0005
O.0005
0.010
0.006
0.036
0.029
0.079
0.042
0.0005
0.0005
O.004
0.004
0.012
0.019
0.055
0.079
RPD
10
8.3
0.9
0
67
ND
62
22
67
56
67
29
ND
ND
11
18
36
3.5
1.3
2.4
ND
ND
ND
67
0
5.4
10
53
Rep values in boldface text represent results where one-half the method detection limit was substituted for values
below detection limits to calculate RPD.

   The balance  used for TSS analyses was calibrated routinely  with  weights that were  NIST
   traceable. The laboratory maintained calibration records. The temperature of the drying oven was
   also monitored using a thermometer that was calibrated with an NIST traceable thermometer.
                                               37

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Table 6-3. Laboratory Duplicate Sample Relative Percent Difference Data Summary

                                                         Standard
                         Average              Minimum   Deviation   Objective
      Parameter   Count     (%)    Maximum (%)    (%)       (%)       (%)
Nitrite
Nitrate
Phosphorus
TKN
TSS
24
24
32
36
30
1.6
5.0
4.4
8.7
10
Table 6-4. Laboratory MS/MSD RPD
Parameter
Cadmium
Copper
Nitrite
Nitrate
Phosphorus
Lead
TKN
TSS
Zinc
Count
13
14
12
12
10
14
11
9
13
Average
5.2
1.1
0.2
0.0
1.2
0.9
7.5
4.6
1.1
Table 6-5. Laboratory MS/MSD Data
Parameter
Cadmium
Copper
Nitrite
Nitrate
Phosphorus
Lead
TKN
TSS
Zinc
Count
30
30
28
28
34
32
36
34
30
Average
88
107
103
99
103
100
90
102
102
29
67
43
48
67
0
0
0
0
0
6.1
14
7.8
9.5
15
0-25
0-25
0-30
0-25
0-30
Data Summary
Maximum
19
3
1
0
3
3
16
16
4
Summary
Maximum
124
118
112
120
109
112
113
118
115
Minimum
0
0
0
0
0
0
0
0
0

Minimum
14
99
93
89
84
82
60
70
88
Standard
Deviation
4.9
1.0
0.4
0.0
1.3
0.9
6.8
4.9
1.0

Standard
Deviation
31
6.4
4.3
6.2
6.2
8
13
10.5
6.7
Objective
0-25
0-25
0-25
0-25
0-30
0-25
0-25
0-30
0-25

Objective
80 - 120
80 - 120
75 - 125
75 - 125
70- 130
80 - 120
75 - 125
75 - 125
80 - 120
                                       38

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Table 6-6. Laboratory Control Sample Data Summary
      Parameter    Count  Average (%)
                                                               Standard
                                        Maximum   Minimum   Deviation   Objective
Cadmium
Copper
Nitrite
Nitrate
Phosphorus
Lead
TKN
TSS
Zinc
16
16
14
14
17
16
19
16
16
107
100
105
98
105
102
93
99
102
129
110
112
104
110
107
120
103
105
83
95
102
95
100
97
74
92
99
12
4.0
2.8
2.7
3.2
2.5
12
3.0
2.0
80-
80-
75-
75-
70-
80-
75-
75-
80-
120
120
125
125
130
120
125
125
120
6.1.4  Representativeness

The field procedures were designed to ensure that representative samples were collected of both
influent and effluent  stormwater. Field duplicate samples  and supervisor oversight provided
assurance that  procedures  were being followed. The challenge in sampling  stormwater is
obtaining  representative samples. The data indicated  that while individual sample  variability
might occur,  the  long-term trend in the data was representative of the concentrations in the
stormwater, and redundant methods  of evaluating key constituent loadings in the stormwater
were utilized to compensate for the variability of the laboratory data.

The  laboratories  used standard  analytical methods, with written SOPs for each method, to
provide a consistent approach  to   all analyses. Sample  handling,  storage,  and  analytical
methodology were reviewed to verify that standard procedures were being followed. The use of
standard methodology, supported by proper quality control information and audits, ensured that
the analytical data were representative of actual stormwater conditions.

6.1.5  Completeness

Completeness is a measure of the number of valid samples and measurements that are obtained
during a test period. Completeness will be measured by tracking the number of valid data results
against the specified requirements of the test plan. The goal for this data quality objective was to
achieve 80% completeness for flow and analytical data. The data quality objective was exceeded,
with discrepancies noted below:

   •   The flow data (15 events, three monitoring locations per event) is complete for all of the
       monitored events, except for  5 missing data sets: from the upstream flow monitor for
       events 7 and 8, biased upstream data for events 9 and  13, and an incorrect inlet water
       level data reading for event 11. This resulted in the  flow data being 89% complete.

   •   SSC data were not analyzed from event 7 due to insufficient sample volume collected.
                                           39

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   •   Two sets of nitrate and nitrite samples (from events 6 and 7) were not analyzed by the
       analytical laboratory because the 48-hr hold times had been exceeded.

   •   TSS analytical for the event 15 were analyzed one day outside the 7-day hold time. The
       data was reported as an estimated concentration.

These issues are appropriately flagged in the analytical reports and the data used in the final
evaluation of the StormFilter device.
                                           40

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                                     Chapter 7
                     Operations and Maintenance Activities

7.1    System Operation and Maintenance

SMI recommends initially scheduling one minor inspection and one major maintenance activity
per year for a typical installation.  A minor  maintenance activity and inspection consists of
visually inspecting the unit and removing trash and debris. During this activity,  the need for
major  maintenance  should  be  determined.  A  major  maintenance  consists  of  pumping
accumulated sediment and water from the vault and replacing the filter cartridges. SMI indicates
that the sedimentation rate is the primary factor for determining maintenance frequency, and that
a maintenance schedule should be based on site-specific sedimentation conditions.

Installation of the StormFilter was  completed in July 2002. In the fall of 2002, the  sampling
equipment was installed, and several shakedown events were sampled. ETV monitoring of the
system began in  the spring of 2003.  The  StormFilter was cleaned  in February 2003,  and
inspected in August 2003, January 2004, May 2004, and December 2004.

A major maintenance procedure was conducted on the StormFilter on February 18-20, 2003, by
SMI personnel, supervised by TO personnel. A local industrial  service company with a Vactor
truck. Maintenance consisted of dewatering the influent and cartridge bays,  removing  the spent
filter  media and  accumulated  sediment  from the vault, replacing  the filter cartridges,  and
inspecting the StormFilter components for damage.  The plastic filter cartridge components from
the spent filter cartridges were shipped back to SMI for cleaning, repair, and reuse. During the
maintenance, SMI personnel repaired a damaged coupling that caused one filter cartridge in the
middle of the vault to become dislodged.

A minor maintenance and inspection on the StormFilter was conducted on December 1, 2004, by
SMI personnel, supervised by the TO and VO. The accumulated sediment in the inlet  and filter
chambers was measured in ten discrete locations, in accordance with a SOP prepared by SMI. In
the inlet chamber, approximately 4.75 in. of accumulated sediment was observed. In the filter
chamber, the accumulated sediment depth ranged from 0 to 3.5 in., and averaged approximately
2.6 in. There were no structural or operational issues  with the StormFilter noted during the
inspection.
                                          41

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                                     Chapter 8
                                     References
1.  APHA, AWWA,  and WEF.  Standard  Methods for  the  Examination  of Water  and
   Wastewater, 19th ed. Washington, DC, 1995.

2.  Fishman, M. J., Raese, J. W.,  Gerlitz, C. N., Husband, R. A., U.S. Geological  Survey.
   Approved Inorganic and Organic Methods for the Analysis of Water and Fluvial Sediment,
   1954-94, USGS OFR 94-351, 1994.

3.  National Oceanic  and Atmospheric  Administration (NOAA).  Technical Paper  No.  40
   Rainfall Frequency Atlas of the United States. Washington, DC, 2000.

4.  NSF  International and Paragon  Consulting  Group.  Test Plan for  the  Verification  of
   StormFilter  Technologies, Inc.,  The StormFilter Separation System,  TEA-21 Project Area,
   City of Griffin, Spalding County,  Georgia. June 2003.

5.  NSF  International.  ETV  Verification Protocol  Stormwater  Source  Area   Treatment
   Technologies. U.S. EPA Environmental Technology Verification Program; EPA/NSF Wet-
   weather Flow Technologies Pilot. March 2002 (v. 4.1).

6.  United  States  Environmental Protection Agency. Methods and Guidance for Analysis  of
   Water, EPA 821-C-99-008, Office of Water, Washington, DC, 1999.
                                          42

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                                  Appendices
A     StormFilter Design and O&M Guidelines
B     Verification Test Plan
C     Event Hydrographs and Rain Distribution
D     Analytical Data Reports with QC
                                       43

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