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
CATCHBASIN STORMFILTER™
ST. CLAIR SHORES, MICHIGAN
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 CatchBasin
StormFilter™ (CBSF) manufactured by Stormwater Management, Inc. (SMI), of Portland, Oregon. The
CBSF was installed at the St. Clair Shores Department of Public Works (DPW) yard in St. Clair Shores,
Michigan. Environmental Consulting & Technology, Inc. (ECT) of Detroit, Michigan performed the
testing.
The ETV program was created 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.
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The accompanying notice is an integral part of this verification statement.
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TECHNOLOGY DESCRIPTION
The following description of the CBSF was provided by the vendor and does not represent verified
information.
The four-cartridge CBSF consists of a storm grate and filter chamber inlet bay, flow spreader, cartridge
bay, overflow baffle, and outlet bay, housed in a 10.25 ft by 2 ft steel 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 stormwater with a maximum flow rate of
60 gpm. Flows greater than the maximum flow rate would pass the overflow baffle to the discharge pipe,
bypassing the filter media.
The CBSF contains filter cartridges filled with SMFs CSF filter media (an organic granular media made
from composted deciduous leaves), which is designed to remove sediments, metals, and other stormwater
pollutants from wet weather runoff. Water in the cartridge bay infiltrates the filter media into 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.
The CBSF is equipped with an overflow weir designed to bypass flows exceeding the peak hydraulic
treatment capacity and prevent catch basin backup and surface flooding. The bypass flow is discharged
through the outlet pipe along with the treated water.
The vendor claims that a single StormFilter cartridge configured to treat flows at 15 gpm using a coarse
perlite media was shown to have a TSS removal efficiency of 79% (with 95% confidence limits of 78%
and 80%) for a sandy loam material comprised of 55% sand, 45% silt, 5% clay (USDA) by mass, in
laboratory studies using simulated stormwater, and can also remove metals and oil and grease from wet-
weather flows. The vendor did not provide specific claims for the removal efficiency of the CSF media,
used in this verification. Further detail about the specific vendor claims appears in the verification report.
VERIFICATION TESTING DESCRIPTION
Methods and Procedures
The test methods and procedures used during the study are described in the Test Plan for Stormwater
Management, Inc. Storm Filter, November 5, 2002. The CBSF received runoff collected from an
impervious 0.16-acre portion of the DPW yard, where uncovered stockpiles of sand, gravel, construction
debris and excavated aggregate consisting of sand, silt, topsoil and clay, are maintained. Southeast
Michigan receives an annual average of nearly 37 in. of precipitation, and experiences warm to hot
summers and cold, snowy winters.
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 (snow
fall and snow melt events did not qualify);
• 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.
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Automated monitoring and sample collection devices were installed to collect composite samples from
the influent and effluent during qualified flow events. Additional influent and effluent sample ports were
also installed so that discrete samples could be collected by manually actuating peristaltic pumps to
collect samples for hydrocarbon analysis. In addition to the flow and analytical data, operation and
maintenance (O&M) data were recorded. Samples were analyzed for the following parameters:
Sediments Metals Hydrocarbons
• total suspended solids • total and dissolved • total petroleum hydrocarbons (TPH),
(TSS) cadmium, lead, gasoline-range organics (GRO) and diesel-
• suspended sediment copper and zinc range organics (DRO)
concentration (SSC) • polynuclear aromatic hydrocarbons (PAH)
VERIFICATION OF PERFORMANCE
Verification testing of the CBSF lasted approximately 13 months, with four months off during the winter
of 2004. Sixteen storm events were successfully sampled. However, due to problems with the automated
sampling equipment in 2003, ECT collected flow-weighted aliquots for all analyses by manually
actuating the peristaltic pump for events 1 through 6 and event 8. During remobilization in the spring of
2004, ECT and SMI debugged the automated sampling equipment, and for all subsequent events, samples
for sediment and metals analyses were collected with the automated sampling equipment.
Test Results
The ETV protocol and test plan do not specify maximum sediment concentration in stormwater, nor did
SMI's literature specify a maximum sustained concentration for their stormwater treatment devices to
function effectively. However, the vendor, TO, and VO recognized that the sediment loadings in this
drainage basin were atypical, and exceeded a concentration and mass loading range in which a valid
measure of the removal performance of the CBSF could be conducted. According to the vendor, the four-
cartridge CBSF has a maximum sediment storage capacity of 27 ft3 or 200 gal in the sump, plus a
maximum of 100 Ib in the cartridges (25 Ib per cartridge). The influent calculated sum of loads (SOL)
mass for TSS and SSC was approximately 2,000 Ib for all events. Based on SOL calculations, the
sediment loadings for qualified events likely exceeded the CBSF sediment capacity after only a few
events.
The precipitation data for the rain events are summarized in Table 1. The peak runoff intensity exceeded
the CBSF peak hydraulic treatment capacity of 60 gpm during 10 of the 16 events, which means that a
portion of the flow bypassed the filtering process during these events. During high flow conditions, the
effluent includes both filtered and unfiltered water, so these values do not represent the performance of
the system under designed flow conditions. Recorded flow volumes were substantially higher than
predicted using the rational method, especially during events with higher peak discharge rates.
The monitoring results were evaluated using event mean concentration (EMC) and SOL comparisons.
The EMC or efficiency ratio comparison evaluates treatment efficiency on a percentage basis by dividing
the effluent concentration by the influent concentration and multiplying the quotient by 100. The
efficiency ratio 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 product of multiplying the parameter concentration by the precipitation volume)
for all storm events. The calculation is made by subtracting the quotient of the total effluent load divided
by the total influent load from one, 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.
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Table 1. Rainfall Data Summary
Rainfall
Event Start Start Amount
Number Date Time (in.)
1 9/22/03 7:40 0.31
2 9/26/03 23:50 0.26
3 10/14/03 11:14 0.68
4 11/18/03 7:50 0.44
5 11/24/03 4:09 0.33
6 12/10/03 14:05 0.75
7 12/23/03 3:34 0.42
8 12/29/03 8:25 0.31
9 1/1/04 21:51 0.20
10 5/10/04 22:26 0.29
11 5/23/04 18:45 1.39
12 6/10/04 13:09 0.28
13 7/7/04 15:12 0.30
14 7/14/04 16:25 0.18
15 8/28/04 7:21 0.52
16 10/23/04 19:25 0.21
Rainfall
Duration
(hr:min)
1:45
2:00
6:30
17:45
10:45
7:45
10:30
7:45
2:30
3:30
3:45
2:30
1:45
0:45
2:45
4:30
Runoff
Volume
(gal)
2,990
1,510
2,950
4,940
17,900
19,800
11,200
2,270
868
4,450
22,500
5,030
3,700
3,330
10,100
3,970
Peak Discharge
Rate (gpm)
196
44
41
13
99
85
85
9
10
273
335
171
274
175
223
39
Table 2. Analytical Data, EMC Range, and SOL Reduction Results
Influent
Parameter Units Range
TSS mg/L 1,100-5,200
SSC mg/L 930-9,100
Total cadmium Mg/L 0.6-44
Total copper p.g/L 6.0 - 390
Total lead (ig/L 15-580
Total zinc (ig/L 72 - 1,800
Dissolved cadmium1 Mg/L <0.2 - 2.0
Dissolved copper1 (ig/L <1.0-35
Dissolved lead1 (ig/L <1 .0 - 49
Dissolved zinc1 (ig/L <2.0 - 200
TPH-GRO pg/L < 1 00 - < 1 00
TPH-DRO mg/L <0.001-52
PAH2 jjg/L <1. 0-7.5
Effluent
Range
570-8,600
700 - 12,000
O.2-7.6
6.6-250
3.2-200
24- 1,100
O.2-1.8
<1.0-120
<1.0-80
<2.0-170
<100-<100
<0.001- 19
<1.0-3.6
EMC Range
(%)
-120-63
-44 - 53
-41-87
-64 - 42
-47 - 79
-82 - 70
-9-10
-3,400-31
-560-33
-3,400 - 69
NC
-41-93
52-81
SOL Reduction
(%)
11
9.2
52
20
20
29
-20
-34
-0.44
-3.9
NC
62
64
1. Negative EMC values for dissolved metals were skewed by non-detected concentrations in the influent
sample and detected concentrations in the paired effluent sample.2. Ten of 17 PAH compounds were
detected only during events 4, 12, and 14. PAH SOL reduction calculated from sum of all detected
PAH compounds during these three events.
NC: Not calculated.
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The accompanying notice is an integral part of this verification statement.
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In spite of the excessive sediment loadings, the sediment SOL data were further evaluated to assess the
performance impacts of maintenance activities and events where bypass did not occur. This data
indicated a 34% TSS SOL reduction for the first three events following maintenance, as compared to a
3.1% reduction for all other events. Furthermore, the data indicated a 40% SSC SOL reduction for events
where bypass did not occur, compared to a 1.5% reduction for events where bypass occurred.
System Operation
The StormFilter was installed by DPW personnel, under the supervision of ECT. The installation took
approximately two days. No major problems with the CBSF were noted during installation; however,
pipe scaling and blockage downstream of the CBSF was detected after the CBSF was installed.
Addressing this issue delayed the start of verification testing.
The CBSF was cleaned and equipped with new filter cartridges prior to the start of verification and in the
spring of 2004, before verification resumed after winter demobilization, and at the end of verification.
The CBSF vaults are easily accessible from the ground surface, which makes cartridge replacement and
sediment removal easy. According to the vendor, spent filter cartridges weigh approximately 250 Ib each,
and, if mishandled, can cause damage to the PVC under-drain manifold in the vault.
The CBSF's PVC under-drain manifold was not fully assembled when it was delivered to the DPW, and
became disassembled during the shakedown period. The TO dry fit the manifold components when
verification testing began. The first two events were sampled with the manifold either partially
disassembled or dry fit but not sealed. When SMI was informed of this condition, they responded by
sending a repair technician to the DPW to properly assemble and seal the manifold.
Vendor Comments
The vendor included a chapter in the verification report asserting that the data were collected from filters
that were severely impacted by exceedingly high solids loads, sampled in a completely occluded
condition, and that the sediment loadings and concentrations experienced at the site were substantially
higher than the range they would recommend for usage of the CBSF without site controls or pretreatment.
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.
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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 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
05/22/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/erv (electronic copy)
EPA website: https://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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