September 2005
05/24/WQPC-WWF
EPA/600/R-05/140
Environmental Technology
Verification Report
Stormwater Source Area Treatment
Device
Vortechnics, Inc.
Vortechs® System, Model 1000
Prepared by
NSF International
Under a Cooperative Agreement with
U.S. Environmental Protection Agency
-------
Environmental Technology Verification Report
Stormwater Source Area Treatment Device
Vortechnics, Inc.
Vortechs® System, Model 1000
Prepared for:
NSF International
Ann Arbor, MI 48105
Prepared by:
Earth Tech Inc.
Madison, Wisconsin
With assistance from:
United States Geologic Survey (Wisconsin Division)
Wisconsin Department of Natural Resources
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
September 2005
-------
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
VORTECHS® SYSTEM, MODEL 1000
MILWAUKEE, WISCONSIN
VORTECHNICS, INC.
200 Enterprise Drive
Scarborough, Maine 04074
http://www.vortechnics.com
info@vortechnics.com
PHONE: (877)907-8676
FAX: (207)878-2735
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 Vortechs® System,
Model 1000 (Vortechs), manufactured by Vortechnics, Inc. (Vortechnics). The Vortechs was installed at
the "Riverwalk" site in Milwaukee, Wisconsin. Earth Tech, Inc. and the United States Geologic Survey
(USGS) 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 ETV program's
goal 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.
05/24/WQPC-WWF
The accompanying notice is an integral part of this verification statement.
VS-i
September 2005
-------
TECHNOLOGY DESCRIPTION
The following description of the Vortechs was provided by the vendor and does not represent verified
information.
The Vortechs is designed to remove settable and floatable pollutants from stormwater runoff. Based on
the size of the grit chamber, the Vortechs Model 1000 maximum operating flow rate is 1.6 cfs (720 gpm).
Untreated stormwater enters the Vortechs through an inlet pipe that is tangential to the grit chamber. This
creates a swirling motion that directs settleable solids into a pile towards the center of the grit chamber.
Floating pollutants are trapped upstream of an underflow baffle. The Vortechs contains two flow controls
in the last chamber of the system. The first control is designed to allow nearly-free discharge at very low
flows so that very fine particles do not settle in the inlet pipe. This control begins to create a significant
backwater at operating rates in excess of 5 gpm/ft2 of grit chamber surface area such that the inlet pipe
becomes submerged at an operating rate of 20 gpm/ft2 of grit chamber surface area. This backwater
creates a low-velocity entry into the grit chamber, which encourages stratification of pollutants in the inlet
pipe. Under low flow rates, a small amount of material may settle out in the inlet pipe, but at higher flow
rates, these relatively large particles will be transported into the grit chamber. Additional hydraulic
capacity is provided over the top of the flow control wall so that the system does not cause upstream
flooding at flow rates exceeding the maximum recommended operating rate of 100 gpm/ft2 of grit
chamber surface area.
The vendor claims that the Vortechs will provide a net annual removal efficiency of total suspended
solids (TSS) that are typically encountered in runoff from urban environments in excess of 80%.
According to the vendor's product literature, Vortechnics typically selects a system size that will provide
an 80% annual TSS load reduction based on laboratory-generated performance curves for 50-(im
sediment particles.
VERIFICATION TESTING DESCRIPTION
Methods and Procedures
The test methods and procedures used during the study are described in the Final Test Plan for the
Verification of Vortechs® Model 1000 Stormwater Treatment System, "Riverwalk Site," Milwaukee,
Wisconsin. (March 2004). The Vortechs was installed to treat runoff collected from a 0.25-acre portion of
the westbound highway surface of Interstate 794. Milwaukee receives an average annual precipitation of
nearly 33 in., approximately 31% of which occurs during the summer months. Sampling was not
conducted during winter months. Street sweeping occurred monthly during summer months.
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 inlet and the outlet
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 inlet and outlet during qualified flow events. In addition to the flow and analytical data,
operation and maintenance (O&M) data were recorded. Samples were analyzed for:
05/24/WQPC-WWF The accompanying notice is an integral part of this verification statement. September 2005
VS-ii
-------
Sediments
• TSS
Metals
total and
• total dissolved solids (TDS)
• suspended sediment
concentration (SSC)
• particle size analysis
VERIFICATION OF PERFORMANCE
dissolved
copper and zinc
Nutrients Water Quality Parameters
• total and • chemical oxygen
dissolved demand (COD)
phosphorus • total calcium and
magnesium
Verification testing of the Vortechs lasted approximately 16 months, and coincided with testing
conducted by USGS and the Wisconsin Department of Natural Resources. Conditions during certain
storm events prevented sampling for some parameters. However, samples were successfully taken and
analyzed for all parameters for at least 15 of the 18 total storm events.
In addition to the vendor's claim for sediment removal (TSS), the verification test plan included
measurements for other water quality parameters. These verification factors were developed by a
participating stakeholder group and technology panel, and provide ancillary performance data which is
considered by many municipalities in addition to primary vendor claims when purchasing stormwater
treatment technology.
Environmental conditions and other factors which may have impacted TSS removal are addressed in
Chapter 5 of the full report.
Test Results
Table 1. Rainfall Data Summary
Event
Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Date
4/30/03
5/4/03
5/9/03
5/30/03
6/8/03
6/27/03
9/12/03
9/14/03
10/14/03
10/14/03
10/24/03
3/25/04
3/28/04
4/17/04
5/12/04
5/20/04
8/3/04
8/24/04
Start
Time
22:24
21:34
0:42
19:07
3:34
17:35
15:42
6:09
1:19
8:54
17:41
23:08
15:30
3:29
18:33
16:39
20:25
20:40
Rainfall
Amount
(in.)
1.1
0.72
0.87
0.54
0.62
0.57
0.30
0.47
0.27
0.23
0.71
0.85
0.87
0.24
0.55
0.24
1.8
0.85
Rainfall
Duration
(hnmin)
3:30
4:05
4:27
4:07
11:09
17:25
3:49
6:35
2:53
0:39
5:31
4:57
4:49
1:18
9:05
1:02
3:43
3:32
Runoff
Volume
(ft3)1
847
795
717
665
847
518
156
588
268
138
613
311
216
69
311
259
2,510
449
Peak Flow
Rate (cfs) 1
0.352
0.059
0.084
0.164
0.466
0.101
0.039
2.02
0.057
0.055
0.138
0.023
0.025
0.026
0.076
1.26
2.45
1.02
1. Runoff volume and peak discharge rate measured at the inlet monitoring point. See the
verification report for further details.
2. Peak flow rates exceeded the rated treatment capacity of the Vortechs unit indicating
the unit may be undersized for the drainage area.
05/24/WQPC-WWF
The accompanying notice is an integral part of this verification statement.
VS-iii
September 2005
-------
The monitoring results were evaluated using event mean concentration (EMC) and sum of loads (SOL)
comparisons. The EMC evaluates treatment efficiency on a percentage basis by dividing the outlet
concentration by the inlet 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 inlet and outlet 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 outlet load divided by the total inlet 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
SOL SOL reduction
reduction all events
Inlet Outlet EMC range all events except 8 & 17
Parameter Units range range (%) (%) (%)'
TSS
SSC
TDS
Total phosphorus
Dissolved phosphorus
Total copper
Dissolved copper
Total zinc
Dissolved zinc
Total magnesium
Total calcium
COD2
mg/L
mg/L
mg/L
mg/L as P
mg/L as P
Hg/L
Hg/L
Hg/L
Hg/L
mg/L
mg/L
mg/L
46-
50-
<50-
310
820
290
0.062-0.68
0.014-0.24
21-
5.4-
100-
17-
3.7-
9.5-
27-
280
-75
920
350
-23
-48
310
28-
26-
<50-
150
150
1,400
0.041-0.48
0.007-0.15
13-
120
5.4-43
84-
33-
520
330
2.3-10
9.3-
25-
-43
220
-170 - 70
-90-
90
-1,100-25
-82-
52
-200 - 68
-83-
70
-250 - 52
-80-
-380-
-96-
-120-
58
31
78
65
-170-57
18
58
-120
9.3
0
25
-10
16
-24
42
21
-15
35
61
-110
21
26
33
-12
24
-21
47
22
0
1. The SOL was recalculated excluding events 8 and 17, since the peak runoff intensity for these events
exceeded the rated flow capacity of the Vortechs. Refer to the verification report for further details.
2. The outlet COD concentration for event 4 was 1,400 mg/L but considered an outlier and was not used in
EMC or SOL calculations.
The calculated SOL reduction for TSS, SSC, total and dissolved phosphorus, COD, and total metals
improved when omitting the two events where the peak runoff intensity exceeded the rated flow capacity
of the Vortechs (shown in the last column of Table 2). The high negative TDS removals were likely
influenced by road salting operations. Dissolved-phase constituents, other than dissolved phosphorous,
showed relatively little change when excluding events 8 and 17. The data suggest that scouring or
resuspension may have occurred as a result of the high peak flow rates encountered during events 8 and
17.
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 sand in the inlet
ranged from 2% to 58%, while the percentage of sand in the outlet ranged from 0% to 19%. This data
was incorporated into the SOL calculation, revealing the reduction in the SSC sand fraction was 94% and
the reduction in the SSC silt fraction was 21%.
05/24/WQPC-WWF
The accompanying notice is an integral part of this verification statement.
VS-iv
September 2005
-------
System Operation
The Vortechs was installed in December 2001, prior to verification, so verification of installation
procedures on the system was not documented. The installed system cleaned and was inspected
immediately prior to and during verification. Seven inspections of the unit were also performed during the
test period. Upon completing the verification testing, the sediment chamber was cleaned out and
contained sediment at depths ranging from 0 to 5.75 in., and approximately 120 Ib (dry weight) of
sediment was removed from the sediment chamber.
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
05/24/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.
05/24/WQPC-WWF The accompanying notice is an integral part of this verification statement. September 2005
VS-v
-------
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.
-------
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 Vortechs® System, Model 1000 was conducted at a testing
site in downtown Milwaukee, Wisconsin, maintained by Wisconsin Department of
Transportation (WisDOT).
The U.S. Environmental Protection Agency (EPA) is charged by Congress with protecting the
Nation's land, air, and water resources. Under a mandate of national environmental laws, the
Agency strives to formulate and implement actions leading to a compatible balance between
human activities and the ability of natural systems to support and nurture life. To meet this
mandate, EPA's research program is providing data and technical support for solving
environmental problems today and building a science knowledge base necessary to manage our
ecological resources wisely, understand how pollutants affect our health, and prevent or reduce
environmental risks in the future.
The National Risk Management Research Laboratory (NRMRL) is the Agency's center for
investigation of technological and management approaches for preventing and reducing risks
from pollution that threaten human health and the environment. The focus of the Laboratory's
research program is on methods and their cost-effectiveness for prevention and control of
pollution to air, land, water, and subsurface resources; protection of water quality in public water
systems; remediation of contaminated sites, sediments and ground water; prevention and control
of indoor air pollution; and restoration of ecosystems. NRMRL collaborates with both public
and private sector partners to foster technologies that reduce the cost of compliance and to
anticipate emerging problems. NRMRL's research provides solutions to environmental
problems by: developing and promoting technologies that protect and improve the environment;
advancing scientific and engineering information to support regulatory and policy decisions; and
providing the technical support and information transfer to ensure implementation of
environmental regulations and strategies at the national, state, and community levels.
This publication has been produced as part of the Laboratory's strategic long-term research plan.
It is published and made available by EPA's Office of Research and Development to assist the
user community and to link researchers with their clients.
11
-------
Contents
Verification Statement VS-i
Notice i
Foreword ii
Contents iii
Figures iv
Tables iv
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
1.3 System Owner/Operator 4
Chapter 2 Technology Description 6
2.1 Treatment System Description 6
2.2 Maintenance 7
2.3 Technology Application and Limitations 8
2.4 Performance Claim 8
Chapters Test Site Description 9
3.1 Location and Land Use 9
3.2 Contaminant Sources and Site Maintenance 11
3.3 Stormwater Conveyance System 11
3.4 Water Quality /Water Resources 11
3.5 Local Meteorological Conditions 12
Chapter 4 Sampling Procedures and Analytical Methods 13
4.1 Sampling Locations 13
4.1.1 Site 1 -Inlet 13
4.1.2 Site 2 - Treated Outlet 13
4.1.3 Other Monitoring Locations 14
4.2 Monitoring Equipment 15
4.3 Contaminant Constituents Analyzed 15
4.4 Sampling Schedule 16
4.5 Field Procedures for Sample Handling and Preservation 18
Chapter 5 Monitoring Results and Discussion 20
5.1 Monitoring Results: Performance Parameters 20
5.1.1 Concentration Efficiency Ratio 20
5.1.2 Sum of Loads 26
5.2 Particle Size Distribution 31
Chapter 6 QA/QC Results and Summary 34
6.1 Laboratory/Analytical Data QA/QC 34
6.1.1 Bias (Field Blanks) 34
6.1.2 Replicates (Precision) 35
in
-------
6.1.3 Accuracy 37
6.1.4 Representativeness 38
6.1.5 Completeness 39
6.2 Flow Measurement Calibration 39
6.2.1 Stage Measurement Corrections 39
6.2.2 Flow Calibration -InletFlume Measurements 40
6.2.3 Developing the Rating Curve 41
6.2.4 Outlet Volume Comparison 42
6.2.5 Comparison of Runoff Volumes: Rainfall Depth vs. Inlet Measurements ... 42
6.2.6 Point Velocity Correction 44
Chapter 7 Operations and Maintenance Activities 45
7.1 System Operation and Maintenance 45
7.2 Description of Post Monitoring Cleanout and Results 46
7.2.1 Background 46
Chapter 8 References 49
Glossary 50
Appendices 52
A Vortechs Design and O&M Guidelines 52
B Test Plan 52
C Event Hydrographs and Rain Distribution 52
C Analytical Data Reports with QC 52
Figures
Figure 2-1. Schematic drawing of atypical Vortechs 7
Figure 3-1. Test site location 9
Figure 3-2. Drainage area detail 10
Figure 3-3. Vortechs drainage area condition 10
Figure 3-4. Reconfigured inlet to Vortechs 12
Figure 4-1. View of monitoring station 13
Figure 4-2. View of ISCO samplers 14
Figure 4-3. View of datalogger 14
Figure 4-4. View of rain gauge 15
Figure 6-1. Calculated rating curve for Vortechs inlet site 42
Tables
Table 4-1. Constituent List for Water Quality Monitoring 16
Table 4-2. Summary of Events Monitored for Verification Testing 17
Table 4-3. Rainfall Summary for Monitored Events 18
Table 5-1. Monitoring Results and Efficiency Ratios for Sediment Parameters 21
Table 5-2. Monitoring Results and Efficiency Ratios for Phosphorus Parameters 23
Table 5-3. Monitoring Results and Efficiency Ratios for Metals 24
Table 5-4. Monitoring Results and Efficiency Ratios for Water Quality Parameters 25
Table 5-5. Sediment Sum of Loads Results 27
IV
-------
Table 5-6. Nutrient Sum of Loads Results 28
Table 5-7. Metals Sum of Loads Results 30
Table 5-8. Water Quality Parameters Sum of Loads Results 31
Table 5-9. Particle Size Distribution Analysis Results 32
Table 5-10. Particle Size Distribution SOL Results 33
Table 6-1. Field Blank Analytical Data Summary 34
Table 6-2. Field Duplicate Sample Relative Percent Difference Data Summary 36
Table 6-3. Laboratory Duplicate Sample Relative Percent Difference Data Summary 37
Table 6-4. Laboratory MS/MSD Data Summary 38
Table 6-5. Laboratory Control Sample Data Summary 38
Table 6-6. Stage Height Corrections 40
Table 6-7. Comparison of Runoff Volumes 43
Table 7-1. Operation and Maintenance During Verification Testing 45
-------
Abbreviations and Acronyms
ASTM
BMP
cfs
COD
EMC
EPA
ETV
ft2
ft3
g
gal
gpm
hr
in.
kg
L
Ib
LOD
LOQ
m3
mm
NRMRL
mg/L
min
MS/MSD
NSF
NIST
O&M
QA
QAPP
QC
RPD
ssc
SOL
SOP
Std. Dev.
IDS
TO
TP
TSS
USGS
VA
vo
American Society for Testing and Materials
Best Management Practice
Cubic feet per second
Chemical oxygen demand
Event mean concentration
U.S. Environmental Protection Agency
Environmental Technology Verification
Square feet
Cubic feet
Gram
Gallon
Gallon per minute
Hour
Inch
Kilogram
Liters
Pound
Limit of detection
Limit of quantification
Cubic meter
Millimeter
National Risk Management Research Laboratory
Microgram per liter (ppb)
Micron (micrometer)
Milligram per liter
Minute
Matrix spike/matrix spike duplicate
NSF International, formerly known as National Sanitation Foundation
National Institute of Standards and Technology
Operations and maintenance
Quality assurance
Quality Assurance Project Plan
Quality control
Relative percent difference
Suspended sediment concentration
Sum of loads
Standard operating procedure
Standard deviation
Total dissolved solids
Testing Organization
Total phosphorus
Total suspended solids
United States Geological Survey
Visual accumulator
Verification Organization (NSF)
VI
-------
WDNR Wisconsin Department of Natural Resources
WQPC Water Quality Protection Center
WisDOT Wisconsin Department of Transportation
WSLH Wisconsin State Laboratory of Hygiene
yd3 Cubic yard
vn
-------
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; stakeholders
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 Vortechs® System, Model 1000
(Vortechs), a stormwater treatment device designed to remove suspended solids, and other
stormwater 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 Vortechs was a cooperative effort among the following participants:
• U.S. Environmental Protection Agency
• NSF International
• U.S. Geologic Survey (USGS)
• Wisconsin Department of Transportation (WisDOT)
• Wisconsin Department of Natural Resources (WDNR)
• Wisconsin State Laboratory of Hygiene (WSLH)
• USGS Sediment Laboratory
• Earth Tech, Inc.
• Vortechnics, Inc. (Vortechnics)
-------
The following is a brief description of each ETV participant and their roles and responsibilities.
7.2.7 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 Center and partial support for the cost of testing for this verification.
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
7.2.2 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 also provided
review of the test plan and this 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.
-------
Key contacts at NSF are:
Mr. Thomas Stevens, P.E. Mr. Patrick Davison,
Program Manager Project Coordinator
(734) 769-5347 (734) 913-5719
email: stevenst@nsf.org email: davison@nsf.org
NSF International
789 North Dixboro Road
Ann Arbor, Michigan 48105
1.2.3 Testing Organization
The TO for the verification testing was Earth Tech, Inc. of Madison, Wisconsin (Earth Tech),
with assistance from USGS in Middleton, Wisconsin. USGS provided testing equipment, helped
to define field procedures, conducted the field testing, coordinated with the analytical
laboratories, and conducted initial data analyses.
The TO provided all needed logistical support, established a communications network, and
scheduled and coordinated activities of all participants. 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, evaluated,
interpreted and reported on the data generated during the testing, as well as evaluated and
reported on the performance of the technology. TO employees set test conditions, and measured
and recorded data during the testing. The TO's Project Manager provided project oversight.
The key personnel and contacts for the TO are:
Earth Tech:
Mr. Jim Bachhuber, P.H.
(608)828-8121
email: jim_bachhuber@earthtech. com
Earth Tech, Inc.
1210 Fourier Drive
Madison, Wisconsin 53717
USGS:
Ms. Judy Horwatich
(608) 821-3874
email: jawierl@usgs.gov
-------
USGS
8505 Research Way
Middleton, Wisconsin 53562
1.2.4 Analytical Laboratories
The WSLH, located in Madison, Wisconsin, analyzed the stormwater samples for the parameters
identified in the test plan. The USGS Sediment Laboratory, located in Iowa City, Iowa,
performed the suspended sediment concentration separations and particle size analyses for the
first qualified event.
The key analytical laboratory contacts are:
Mr. George Bowman Ms. Pam Smith
(608) 224-6279 (319) 358-3602
email: gtb@mail.slh.wisc.edu email: pksmith@usgs.gov
WSLH USGS Sediment Laboratory
2601 Agriculture Drive Federal Building Room 269
Madison, Wisconsin 53718 400 South Clinton Street
Iowa City, Iowa 52240
7.2.5 Vendor
The Vortechs is designed by Vortechnics, headquartered in Scarborough, Maine and
manufactured by a local pre-cast company (Wiesser Concrete in Maiden Rock, Wisconsin).
Vortechnics is owned by Contech Construction Products Inc., headquartered in Middletown,
Ohio. Vortechnics was responsible for providing technical support, and was available during the
tests to provide technical assistance as needed.
The key contact for Vortechnics is:
Mr. Vaikko P. Allen II, Technical Manager
(207) 885-9830, ext. 275
email: vallen@vortechnics.com
Vortechnics, Inc.
200 Enterprise Drive
Scarborough, Maine 04074
1.3 System Owner/Operator
The Vortechs was installed in a parking lot under Interstate 794 on the east side of the
Milwaukee River in downtown Milwaukee, Wisconsin. The Vortechs treated storm water
collected from the decking of Interstate 794. The unit was installed in cooperation with
WisDOT, the current owner/operator of the system.
-------
The key contact for WisDOT is:
Mr. Robert Pearson
(608) 266-7980
email: robert.pearson@dot.state.wi.us
Bureau of Environment
Wisconsin Department of Transportation
4802 Sheboygan Avenue, Room 451
Madison, Wisconsin 53707
-------
Chapter 2
Technology Description
The following technology description data was supplied by the vendor and does not represent
verified information.
2.1 Treatment System Description
The Vortechs is designed to remove settable and floatable pollutants from stormwater runoff.
When the system is operating at its peak design capacity, the maximum operating rate is
approximately 100 gpm/ft2 of surface area. The Vortechs has been tested in a laboratory at flows
up to and including this maximum treatment rate and has been shown to produce positive
sediment removal efficiencies throughout this range. Based on the size of the grit chamber for
the Vortechs Model 1000, the maximum treatment flow rate is 1.6 cfs (720 gpm).
Additional hydraulic capacity is provided over the top of the flow control wall so that the system
does not cause upstream flooding at flow rates exceeding the maximum recommended operating
rate of 100 gpm/ft2. The actual hydraulic capacity of on-line Vortechs Systems is typically at
least as great as the 100-year peak flow rate or the drainage system conveyance capacity,
whichever is less.
A schematic of the Vortechs is shown in Figure 2-1 The Vortchs consists of an inlet pipe, grit
chamber, baffle walls, and an outlet pipe, enclosed in a concrete vault. Untreated stormwater
enters the Vortechs through an inlet pipe that is tangential to the grit chamber. This creates a
swirling motion that directs settleable solids downward and towards the center of the grit
chamber. Floating pollutants are trapped upstream of an underflow baffle. The Vortechs
contains two flow controls in the last chamber of the system. The first control is designed to
allow nearly free discharge at very low flows so that very fine particles do not settle in the inlet
pipe. This control begins to create a significant backwater at operating rates in excess of
5 gpm/ft2 such that the inlet pipe becomes submerged at an operating rate of 20 gpm/ft2. This
backwater creates a low-velocity entry into the grit chamber, which encourages stratification of
pollutants in the inlet pipe. Under low flow rates, a small amount of material may settle out in
the inlet pipe, but at higher flow rates, these particles will be transported into the grit chamber.
At operating rates in excess of 20 gpm/ft2, a portion of the flow will pass through the high flow
control. The flow controls were sized to create up to 3.5 ft of backwater at peak operating rates,
depending on available head. This backwater effect increases the residence time in the system,
thereby maximizing pollutant removal and retention. The backwater effect also increases the
separation between captured floating pollutants and the bottom of the baffle wall. Both flow
controls are Cipoletti shape with a flat crest and a side slope of 4:1.
The Vortechs installed at the Riverwalk site in Milwaukee is designed to treat all flows up to
1.6 cfs. There is no bypass, so flows exceeding peak hydraulic capacity will pass through the
system. At high flows, the inlet pipe's capacity becomes the limiting factor.
-------
OH Baffle Will
Into*
High Flow Control
Grit Chamber
Low Row Control
Figure 2-1. Schematic drawing of a typical Vortechs.
Product Specification:
• Housing - Six-inch thick concrete rectangular structure.
• Dimensions - inside dimensions - length: 9 ft (2.7 m); width: 3 ft (1 m); height: 7 ft
(2.1m).
• Peak Treatment Capacity - 1.6 cfs (720 gpm).
• Sediment Storage - 0.75 yd3 (0.57 m3).
• Sediment Chamber Diameter - 3 ft (1 m).
Additional equipment specifications, test site descriptions, testing requirements, sampling
procedures, and analytical methods are detailed in the Final Test Plan for the Verification of
Vortechs* Model 1000 Stormwater Treatment System "Riverwalk Site" Milwaukee, Wisconsin
(March 22, 2004). The test plan is included in Appendix A.
2.2 Maintenance
The Vortechs System should be inspected periodically and cleaned when inspection reveals the
sediment depth has accumulated to within six inches of the dry-weather water level. Maintaining
the Vortechs is easiest when there is no flow entering the system. Cleanout of the Vortechs with
a vacuum truck is generally the most effective and convenient method of excavating pollutants
from the system.
-------
Accumulated sediment is typically evacuated through the manhole over the grit chamber. As
water is evacuated, the water level outside of the grit chamber will drop to the same level as the
crest of the lower aperture of the grit chamber. It will not drop below this level due to the fact
that the bottom and sides of the grit chamber are sealed to the tank floor and walls. This "Water
Lock" feature prevents water from migrating into the grit chamber, exposing the bottom of the
baffle wall. Floating pollutants will decant into the grit chamber as the water level there is drawn
down. This allows most floating material to be withdrawn from the same access point above the
grit chamber. If maintenance is not performed as recommended, sediment may accumulate
outside the grit chamber. If this is the case, it may be necessary to inspect or pump out all
chambers.
2.3 Technology Application and Limitations
The Vortechs is used for several project applications, including:
• commercial developments such as office complexes and hotels;
• industrial developments such as vehicle storage yards and material transfer stations;
• retail developments such as gas stations and shopping centers;
• high-density residential such as housing developments; and
• urban roadways.
2.4 Performance Claim
The vendor claims that the Vortechs will provide a net annual removal efficiency of total
suspended solids (TSS) that are typically encountered in runoff from urban environments in
excess of 80%. According to the vendor's product literature, Vortechnics typically selects a
system size that will provide an 80% annual TSS load reduction based on laboratory-generated
performance curves for 50-|im sediment particles. The vendor also claims that the Vortechs will
capture and contain floatables in stormwater runoff, although this claim was not verified.
-------
Chapter 3
Test Site Description
3.1 Location and Land Use
The Vortechs is located in a municipal parking lot beneath an elevated freeway (1-794) and just
east of the Milwaukee River, in downtown Milwaukee, Wisconsin. The parking lot is located
just west of Water Street, between Clybourn Street and St. Paul Avenue. Figure 3-1 shows the
location of the test site.
Figure 3-1. Test site location.
The Vortechs receives runoff from 0.25 acres of the westbound highway surface of 1-794, as
shown in Figure 3-2. The interstate surface is elevated at this location so there is no other land
use in the drainage area, as shown in Figure 3-3. Surface inlets on the highway, shown in Figure
3-3), collect the runoff and convey the water to the treatment device via downspouts from the
deck surface to beneath the parking lot below the highway deck. The drainage area
determination was based on the following information and assumptions:
1. WisDOT design plans for Interstate 794 dated 1966 (scale: 1 in. equals 20 ft) and
rehabilitation plans dated 1994;
2. The assumption that resurfacing the deck did not change the basic slope or relative
drainage area to each inlet; and
3. The assumption that adjacent storm drains were capable of capturing all the flow in their
respective drainage areas, forming a hydrologic barrier.
-------
J Drainage Area
L
Westbound Traffic -1-794
•i-w
Figure 3-2. Drainage area detail.
Storm inlet to
Vortechs
Figure 3-3. Vortechs drainage area condition.
10
-------
3.2 Contaminant Sources and Site Maintenance
The main pollutant sources within the drainage area are created by vehicular traffic, atmospheric
deposition, and winter salt applications. The storm sewer catch basins do not have sumps.
Conventional (mechanical) street sweeping is done on a monthly basis in the summer months
(June through August). There are no other stormwater best management practices (BMPs)
within the drainage area.
3.3 Stormwater Conveyance System
The entire drainage area is served by a storm sewer collection system. Before installation of the
Vortechs, the drainage area discharged storm water directly to the Milwaukee River through the
system under the parking lot.
The highway deck is elevated approximately 15 ft above the parking lot. Originally, the storm
sewer conveyance system dropped vertically to a point below the parking lot surface, then
traveled about 6.5 ft horizontally to the monitoring (flow and quality) sites, and another two feet
to the Vortechs. After the initial installation of the Vortechs, the velocity meter location was
frequently inundated with sediment during and after events. Vortechnics considered the 2 to 5 ft
of nearly flat storm pipe leading to the grit chamber (this area is affected by backwater effect of
the slot opening to the grit chamber) as part of the treatment system. As a result, sediment was
settling out in this portion of the pipe. The TO and VO decided to reconfigure the storm pipe
(see Figure 3-4) to avoid the interference of the sediment with the velocity meter. The
reconfiguration took place prior to verification testing.
3.4 Water Quality/Water Resources
Stormwater from the site is discharged directly to the Milwaukee River, just upstream of the
mouth to Milwaukee Harbor, and then into Lake Michigan. The river and harbor have had a
history of severe water quality impacts from various sources, including contaminated river
sediments, urban non-point source runoff, rural non-point sources, combined sewer overflows,
and point source discharges. The water quality in the river suffers from low dissolved oxygen,
high nutrient, metals, bacteria levels, and toxic contamination. The Milwaukee River at this
location is on Wisconsin's 303(d) list for dissolved oxygen, aquatic toxicity, polychlorinated
biphenyls, and fish consumption advisory.
Most of the urban communities within the Milwaukee River watershed, including the City of
Milwaukee, are under the State of Wisconsin stormwater-permitting program (NR 216). This
program meets or exceeds the requirements of EPA's Phase I stormwater regulations.
11
-------
r
Enisling vertical
pipe wilh cleanout
will be removed and
stored (or replacemenl
after sampling is
complete. New piping
as shown would preveni
backwater from
Vortecrinics tank al the
moniloring insert. Grade
ol pipe al monitoring
insert will be the same
as exists for Ihe
Stormwater Filler
moniloring insert.
<
Existing Piping
8" Diameter
Sch 80
Gray PVC
New Piping
a' Diameter
Sc:;i R£
Gray PVC
Existing
Overpass
Piaf
0
10
0
8-16
Parking lot slope .068 tt/ft
Clear PVC monitoring Insert
8" Diameter
SL-M eo
Figure 3-4. Reconfigured inlet to Vortechs.
3.5 Local Meteorological Conditions
The test plan includes summary temperature and precipitation data from the National Weather
Service station from the Mitchell Field Airport in Milwaukee. The statistical rainfalls for a series
of recurrence and duration precipitation events are presented in the test plan. The climate of
Milwaukee, and Wisconsin in general, is typically continental with some modification by Lakes
Michigan and Superior. Milwaukee experiences cold snowy winters, and warm to hot summers.
Average annual precipitation is approximately 33 in., with an average annual snowfall of 50.3 in.
12
-------
Chapter 4
Sampling Procedures and Analytical Methods
Descriptions of the sampling locations and methods used during verification testing are
summarized in this section. Additional detail may be found in the test plan.
4.1 Sampling Locations
Two locations in the test site storm sewer system were selected as sampling and monitoring sites
to determine the treatment capability of the Vortechs.
4.1.1 Site 1-Inlet
This sampling and monitoring site was selected to characterize the untreated stormwater from the
drainage area. A velocity/stage meter and sampler suction tubing were located in the inlet pipe,
upstream from the Vortechs, so that potential backwater effects of the treatment device would
not affect the velocity measurements. The monitoring station and test equipment are shown in
Figures 4-1,4-2, and 4-3.
Figure 4-1. View of monitoring station.
4.1.2 Site 2 - Treated Outlet
This sampling and monitoring site was selected to characterize the stormwater treated by the
Vortechs. A velocity/stage meter and sampler suction tubing, connected to the automated
sampling equipment, were located in an eight-inch diameter plastic pipe downstream from the
Vortechs.
13
-------
Figure 4-2. View of ISCO samplers.
Figure 4-3. View of data logger.
4.1.3 Other Monitoring Locations
In addition to the two sampling and monitoring sites, a water-level recording device was
installed inside the Vortechs vault. The purpose of the water level recording device was used to
help verify inlet and outlet flows.
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. The rain gauge is shown in Figure 4-4.
14
-------
Figure 4-4. View of rain gauge.
4.2 Monitoring Equipment
The specific equipment used for monitoring flow, sampling water quality, and measuring rainfall
for the upstream and downstream monitoring points are listed below:
• Sampler: ISCO 3700 refrigerated automatic sampler;
• Sample Containers: Four 10-L sample containers;
• Flow Measurement: Marsh-McBirney Velocity Meter Model 270
• Stage Meter (inside Vortechs vault): Campbell Scientific Inc. SWD1;
• Data Logger: Campbell Scientific, Inc. CR10X; and
• Rain Gauge: Rain-O-Matic.
4.3 Contaminant Constituents Analyzed
The list of constituents analyzed in the stormwater samples is shown in Table 4-1. The vendor's
performance claim addresses reductions of sediments, from the runoff water.
15
-------
Table 4-1. Constituent List for Water Quality Monitoring
Parameter
Total dissolved solids (TDS)
Total suspended solids (TSS)
Total phosphorus
Suspended sediment
concentration (SSC)
Total calcium
Total copper
Dissolved copper
Total magnesium
Dissolved zinc
Total zinc
Dissolved phosphorus
Dissolved chloride
Chemical oxygen demand
(COD)
Sand-silt split
Five point sedigraph
Sand fractionation
Reporting
Units
mg/L
mg/L
mg/L as P
mg/L
mg/L
Mg/L
Mg/L
mg/L
Mg/L
Mg/L
mg/L as P
mg/L
mg/L
NA
NA
NA
Limit of Limit of
Detection Quantification Method1
50
2
0.005
0.1
0.2
1
1
0.2
16
16
0.005
0.6
9
NA
NA
NA
167
7
0.016
0.5
0.7
3
3
0.7
50
50
0.016
2
28
NA
NA
NA
SM 2540C
EPA 160.2
EPA 365.1
ASTMD3977-97
EPA 200.7
SM3113B
SM3113B
EPA 200.7
EPA 200.7
EPA 200.7
EPA 365.1
EPA 325. 2
ASTMD1252-88(B)
Fishman et al.
Fishman et al.
Fishman et al.
1 EPA: EPA Methods and Guidance for the Analysis of Water procedures; SM: Standard Methods for the
Examination of Water and Wastewater (19th edition) procedures; ASTM: American Society of Testing and
Materials procedures; Fishman et al.: Approved Inorganic and Organic Methods for the Analysis of Water and
Fluvial Sediment procedures.
4.4 Sampling Schedule
USGS personnel installed the monitoring equipment under a contract with the WDNR. The
monitoring equipment was installed in December, 2001. During several trial events in 2002, it
was discovered that the inlet velocity meter was frequently inundated with sediment from the
backwater effect of the Vortechs. In January, 2003 the storm pipe was reconfigured to avoid this
problem (see Figure 3-3). Verification testing began in April, 2003, and ended after the last
qualified event was monitored in August, 2004. Testing was suspended during winter weather.
Table 4-2 summarizes the sample collection data from the storm events.
16
-------
Table 4-2. Summary of Events Monitored for Verification Testing
Inlet Sampling Point (Site 1) Outlet Sampling Point (Site 2)
Event Start
Number Date
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
4/30/03
5/4/03
5/9/03
5/30/03
6/8/03
6/27/03
9/12/03
9/14/03
10/14/03
10/14/03
10/24/03
3/25/04
3/28/04
4/17/04
5/12/04
5/20/04
8/3/04
8/24/04
Start
Time
22:24
21:34
0:42
19:07
3:34
17:35
15:42
6:09
1:19
8:54
17:41
23:08
15:30
3:29
18:33
16:39
20:25
20:40
End
Date
5/1/03
5/5/03
5/9/03
5/30/03
6/8/03
6/28/03
9/12/03
9/14/03
10/14/03
10/14/03
10/24/03
3/26/04
3/28/04
4/17/04
5/13/04
5/20/04
8/3/04
8/25/04
End No. of Start
Time Aliquots Date
1:13
0:54
3:41
23:05
13:44
10:46
19:22
12:02
3:04
9:29
21:43
3:34
20:12
4:11
3:27
17:33
23:34
0:02
26
20
5
21
18
20
16
18
15
8
32
31
29
7
14
9
34
17
4/30/03
5/4/03
5/9/03
5/30/03
6/8/03
6/27/03
9/12/03
9/14/03
10/14/03
10/14/03
10/24/03
3/25/04
3/28/04
4/17/04
5/12/04
5/20/04
8/3/04
8/24/04
Start
Time
22:32
21:47
1:53
19:09
3:35
17:37
15:47
11:47
1:23
8:58
17:41
23:33
15:31
3:31
18:36
16:39
20:25
20:42
End
Date
5/1/03
5/5/03
5/9/03
5/30/03
6/8/03
6/28/03
9/12/03
9/14/03
10/14/03
10/14/03
10/24/03
3/26/04
3/28/04
4/17/04
5/13/04
5/20/04
8/3/04
8/24/04
End
Time
0:17
7:10
4:35
22:33
5:00
10:15
17:24
11:59
3:11
9:31
21:42
3:33
18:58
4:12
3:10
17:38
23:53
23:54
No. of
Aliquots
11
16
8
7
7
10
8
6
14
7
29
12
13
7
7
9
26
14
Storm events met the requirements of a "qualified event," as defined in the test plan:
1. The total rainfall depth for the event, measured at the site rain gauge, was 0.2 in.
(5 mm) or greater (snow fall and snow melt events did not qualify).
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
inlet and outlet 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 of the
runoff hydrograph.
5. There was a minimum of six hours between qualified sampling events.
Table 4-3 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 B.
17
-------
Table 4-3. Rainfall Summary for Monitored Events
Event
Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Date
4/30/03
5/4/03
5/9/03
5/30/03
6/8/03
6/27/03
9/12/03
9/14/03
10/14/03
10/14/03
10/24/03
3/25/04
3/28/04
4/17/04
5/12/04
5/20/04
8/3/04
8/24/04
Rainfall
Amount
(inches)
1.1
0.72
0.87
0.54
0.62
0.57
0.30
0.47
0.27
0.23
0.71
0.85
0.87
0.24
0.55
0.24
1.8
0.85
Rainfall
Duration
(hnmin)
3:30
4:05
4:27
4:07
11:09
17:25
3:49
6:35
2:53
0:39
5:31
4:57
4:49
1:18
9:05
1:02
3:43
3:32
Runoff
Volume
(ft3)1
847
795
717
665
847
518
156
588
268
138
613
311
216
69
311
259
2,510
449
Peak
Discharge
Rate (cfs) 1
0.352
0.059
0.084
0.164
0.466
0.101
0.039
2.02
0.057
0.055
0.138
0.023
0.025
0.026
0.076
1.26
2.45
1.02
1. Runoff volume and peak discharge volume measured at the inlet monitoring point.
The vendor sized the Vortechs for the Milwaukee Riverwalk site based on the peak flow rate of
the 1.6 cfs), as noted in Section 2.1. The recorded peak discharge rate for events 8 and 17
exceeded both the peak flow treatment capacity of the Vortechs. Additionally, event 16 nearly
exceeded the peak flow treatment capacity of the Vortechs. At these flow rates, the system was
operating beyond the point at which significant sediment removal is expected.
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 inlet sampler was activated when the
inlet velocity meter sensed flow in the pipe. The outlet sampler was activated when flow was
detected in the outlet pipe.
4.5 Field Procedures for Sample Handling and Preservation
Data gathered by the on-site data logger were accessible to USGS personnel by means of a
modem and phone-line hookup. USGS personnel collected samples and performed a system
inspection after storm events.
18
-------
Water samples were collected with ISCO automatic samplers programmed to collect one-liter
aliquots during each sample cycle. A peristaltic pump in the sampler pumped water from the
sampling location through Teflon™-lined sample tubing to the pump head where water passed
through approximately three feet of silicone tubing and into one of four 10-L sample collection
bottles. Samples were capped and removed from the sampler after the event by the WisDOT or
USGS personnel depending upon the schedule of the staff. The samples were forwarded to
USGS personnel if the WisDOT personnel collected them. The samples were then transported to
the USGS field office in Madison, Wisconsin, where they were split into multiple aliquots using
a 20-L Teflon™-lined churn splitter. When more than 20 L (two 10-L sample collection bottles)
of sample were collected by the auto samplers, the contents of the two full sample containers
would be poured into the churn, a portion of the sample in the churn would be discarded, and a
proportional volume from the third or fourth sample container would be poured into the churn.
The analytical laboratories provided sample bottles. Samples were preserved per method
requirements and analyzed within the holding times allowed by the methods. Particle size and
SSC samples were shipped to the USGS sediment laboratory in Iowa City, Iowa (after event 2,
SSC samples were analyzed at WSLH). All other samples were hand-delivered to WSLH.
The samples were maintained in the custody of the sample collectors, delivered directly to the
laboratory, and relinquished to the laboratory sample custodian(s). 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 Appendix B of the test plan) were completed and accompanied each sample.
19
-------
Chapter 5
Monitoring Results and Discussion
The verification testing results related to contaminant reduction are reported in two formats:
1. Efficiency ratio comparison, which evaluates the effectiveness of the system for each
qualified storm event on an event mean concentration (EMC) basis.
2. Sum of loads (SOL) comparison, which evaluates the effectiveness of the system for
all qualified storm events on a constituent mass (concentration times volume) basis.
The test plan required that a suite of analytical parameters, including solids, metals, and nutrients
be evaluated based on the vendor's performance claim.
5.1 Monitoring Results: Performance Parameters
5.1.1 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-[EMCoutiet/EMCiniet]) (5-1)
The inlet and outlet sample concentrations and calculated efficiency ratios are summarized by
analytical parameter categories: sediments (TSS, SSC, and TDS); nutrients (total and dissolved
phosphorus); metals (total and dissolved copper and zinc); and water quality parameters (COD,
dissolved chloride, total calcium and total magnesium). The water quality parameters were not
specified in the vendors' performance claim and were monitored for other reasons outside the
scope of the ETV program.
Sediments: The inlet and outlet sample concentrations and calculated efficiency ratios for
sediment parameters are summarized in Table 5-1.
The results show differences between inlet TSS and SSC concentrations. Comparing the inlet
concentrations, SSC always exceed TSS, with the range of difference between the two
parameters ranging from 6 to 90%. 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 (generally heavy,
large particle) 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 considerably lower than SSC. For this data set, the
TSS and SSC concentrations were relatively close. This implies that the inlet samples contained
a higher proportion of finer, lighter sediment particles.
20
-------
Table 5-1. Monitoring Results and Efficiency Ratios for Sediment Parameters
Event
No.
1
2
3
4
5
6
7
81
9
10
11
12
13
14
15
16
171
18
Inlet
(mg/L)
79
110
89
110
47
190
310
55
46
130
98
160
270
110
70
97
74
78
TSS
Outlet
(mg/L)
87
38
28
70
64
100
120
150
33
39
83
140
92
110
42
93
87
69
Reduction
(%)
-10
65
69
36
-36
47
61
-170
28
70
15
13
66
0
40
4.1
-18
12
Inlet
(mg/L)
91
160
98
120
50
290
550
79
57
140
110
180
290
130
79
130
220
820
ssc
Outlet
(mg/L)
86
36
27
69
64
100
100
150
26
34
83
140
90
110
41
92
87
79
Reduction
(%)
5.5
78
72
43
-28
66
82
-90
54
76
25
22
69
15
48
29
60
90
Inlet
(mg/L)
54
100
80
88
<50
120
290
<50
82
110
56
180
160
120
80
82
<50
60
TDS
Outlet
(mg/L)
84
120
60
180
140
180
390
96
240
130
130
840
530
1,400
146
120
<50
150
Reduction
(%)
-56
-20
25
-100
ND
-50
-34
ND
-190
-18
-130
-370
-230
-1,100
-83
-46
ND
-150
ND: Not Determined.
1. The Vortechs peak hydraulic capacity was exceeded during events 8 and 17.
21
-------
The TSS inlet concentrations ranged from 55 to 310 mg/L the outlet concentrations ranged from
28 to 150 mg/L, and the efficiency ratio ranged from -170 to 70%. The SSC inlet concentrations
ranged 57 to 820 mg/L, the outlet concentrations ranged from 26 to 153 mg/L, and the efficiency
ratio ranged from -90 to 90%.
The highest inlet TDS concentrations were observed from events 7, 12 and 13. Events 12 and 13
occurred in March 2004, and it is possible that these results were influenced by road salting
operations. This reasoning does not explain the high TDS concentrations found in event 7,
which occurred in September of 2003. For all but one event, the TDS concentrations increased
in the outlet samples. The vendor made no performance claim for TDS.
Phosphorus: The inlet and outlet sample concentrations and calculated efficiency ratios are
summarized in Table 5-2. The total phosphorus inlet concentration ranged from 0.062 mg/L to
0.68 mg/L, and the dissolved phosphorus inlet concentration ranged from 0.014 mg/L to 0.24
mg/L. Reductions in total phosphorus EMCs ranged from -82 to 52%, while reductions in
dissolved phosphorus EMCs ranged from -200 to 68%.
Metals: The inlet and outlet sample concentrations and calculated efficiency ratios are
summarized in Table 5-3. Reductions in metal EMCs followed a similar pattern as the
phosphorus results, in that the total fraction all showed higher concentrations and greater EMC
reductions than the dissolved faction. The total copper inlet concentration ranged from 21 to
280 |ig/L, and the EMC reduction ranged from -83 to 70%. The total zinc inlet concentration
ranged from 102 to 920 |ig/L, and the EMC reduction ranged from -80 to 58%.
The dissolved copper inlet concentration ranged from less than 5 to 75 |ig/L, and the EMC
reduction ranged from -250 to 52%. The dissolved zinc inlet concentration ranged from 17 to
348 |ig/L, and the EMC reduction ranged from -380 to 31%.
Water quality parameters: The inlet and outlet sample concentrations and calculated efficiency
ratios for water quality parameters are summarized in Table 5-4. Total magnesium inlet
concentrations ranged from 3.7 to 23 mg/L, and the EMC reduction ranged from -96 to 78%.
Total calcium inlet concentrations ranged from 9.5 to 48 mg/L, and the EMC reduction ranged
from -120 to 65%. COD inlet concentrations ranged from 27 to 310 mg/L, and the EMC
reduction ranged from -2,000 to 57%. The event with the -2,000% EMC reduction had an outlet
concentration of 1,400 mg/L, which is an outlier. The other COD outlet concentrations ranged
from 25 to 220 mg/L, making the 1,400 mg/L concentration an apparent outlier.
22
-------
Table 5-2. Monitoring Results and Efficiency Ratios for Phosphorus Parameters
Event
No.
1
2
3
4
5
6
7
81
9
10
11
12
13
14
15
16
171
18
Total Phosphorus
Inlet Outlet Reduction
(mg/L) (mg/L) (%)
0.062
0.23
0.086
0.17
0.098
0.35
0.68
0.11
0.13
0.18
0.14
0.13
0.18
0.16
0.13
0.15
0.098
0.23
0.079
0.12
0.041
0.12
0.13
0.27
0.48
0.2
0.15
0.12
0.17
0.14
0.089
0.17
0.12
0.14
0.11
0.14
-27
48
52
29
-33
23
29
-82
-15
33
-21
-7.7
51
-6.3
7.7
6.7
-12
39
Dissolved Phosphorus
Inlet Outlet Reduction
(mg/L) (mg/L) (%)
0.014
0.11
0.016
0.029
0.038
0.098
0.24
0.032
0.072
0.053
0.042
0.021
0.017
0.056
0.058
0.037
0.024
0.042
0.019
0.056
0.007
0.023
0.028
0.033
0.15
0.024
0.03
0.048
0.11
0.017
0.009
0.019
0.028
0.012
0.071
0.03
-36
49
56
21
26
66
38
25
58
9.4
-160
19
47
66
52
68
-200
29
1. The Vortechs peak hydraulic capacity was exceeded during events 8 and 17.
23
-------
Table 5-3. Monitoring Results and Efficiency Ratios for Metals
Total Copper
Event No.
1
2
3
4
5
6
7
81
9
10
11
12
13
14
15
16
171
18
Inlet
(ng/L)
25
64
29
56
26
100
280
35
27
77
51
64
99
21
41
55
36
200
Outlet
(ng/L)
34
24
13
52
33
75
120
64
33
31
51
73
43
36
39
46
28
60
Reduction
-36
63
55
7.1
-27
25
57
-83
-22
60
0
-14
57
-71
4.9
16
22
70
Dissolved Copper
Inlet
(ng/L)
5.4
14
8.1
16
9.9
33
73
9.3
26
75
12
12
14
25
13
16
7.5
13
Outlet
(ng/L)
8.8
11
5.4
19
13
32
35
10
33
32
42
16
12
43 J
19
14
7.8
10
Reduction
-63
21
33
-19
-31
3.0
52
-7.5
-27
57
-250
-33
14
-72
-46
13
-4.0
23
Inlet
(ng/L)
120
270
160
220
100
370
920
150
120
240
180
240
410
240
190
250
130
270
Total Zinc
Outlet
(ng/L)
160
130
84
170
130
250
520
270
130
100
190
280
190
310
150
170
130
170
Reduction
-33
52
48
23
-30
32
43
-80
-8.3
58
-5.6
-17
54
-29
21
32
0
37
Dissolved Zinc
Inlet
(ng/L)
46
100
64
78
43
120
350
42
17
48
47
35
85
110
53
60
33
50
Outlet
(ng/L)
68
78
48
96
62
110
330
70
81
33
170
61
59
160
70
67
38
52
Reduction
-48
22
25
-23
-44
8.3
5.7
-67
-380
31
-260
-74
31
-45
-32
-12
-15
-4.0
J. Estimated concentration; USGS notes indicate possible filter contamination.
1. The Vortechs peak hydraulic capacity was exceeded during events 8 and 17.
24
-------
Table 5-4. Monitoring Results and Efficiency Ratios for Water Quality Parameters
Event
No.
1
2
3
4
5
6
7
81
9
10
11
12
13
14
15
16
171
18
Total Magnesium
Inlet Outlet Reduction
(mg/L) (mg/L) (%)
8.5
9.1
7.2
7.5
3.8
20
19
4.7
3.7
7.7
7.0
11
21
7.4
5.1
6.8
9.5
23
6.5
3
2.3
5.2
5.3
7.7
8.4
9.2
3.2
2.8
5.5
10
6.8
8
3.1
5.8
5.2
5
24
67
68
31
-39
62
56
-96
14
64
21
9.1
68
-8.1
39
15
45
78
Total Calcium
Inlet Outlet Reduction
(mg/L) (mg/L) (%)
20
25
20
18
9.5
48
45
10
15
20
17
29
47
20
13
16
19
48
18
14
9.3
23
21
31
33
20
19
15
17
32
24
43
12
16
12
17
10
44
54
-28
-120
35
27
-100
-27
25
0
-10
49
-120
7.7
0
37
65
Inlet
(mg/L)
27
69
58
66
36
130
310
31
52
90
53
76
100
72
60
57
33
78
COD
Outlet
(mg/L)
39
69
25
1,4002
60
120
220
85
86
55
81
82
55
140
59
56
51
84 J
Reduction
(%)
-44
0
57
-2,000
-67
8
29
-170
-65
39
-53
-7.9
45
-94
1.7
1.8
-55
-7.7
J: Estimated concentration, sample exceeded holding time.
1. The Vortechs peak hydraulic capacity was exceeded during events 8 and 17.
2. COD outlet concentration for event 4 is an apparent outlier and is not used in SOL calculations (Table 5-8).
25
-------
5.1.2 Sum of Loads
The sum of loads (SOL) is the sum of the percent 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 = 100x(l-(A/B)) (5-2)
where:
A = Sum of Outlet Load = (Outlet EMCi)(Flow Volumei) +
(Outlet EMC2)(Flow Volume2) + (Outlet EMCn)(Flow Volumen)
B = Sum of Inlet Load = (Inlet EMCi)(Flow Volumei) +
(Outlet EMC2)(Flow Volume2) + (Outlet EMCn)( Flow Volumen)
n= number of qualified sampling events
Flow was monitored in the inlet and outlet, as discussed in Chapter 3. However, the TO
experienced operational issues with the outlet flow monitor and data, as discussed in Chapter 6.
Therefore, for the purposes of SOL calculations, the inlet flow data was used to calculate both
the inlet and outlet SOL values.
The SOL values are calculated using two approaches:
1. using the flow volumes and concentrations from all qualified events; and
2. using the flow volumes and concentrations from all qualified events except events 8 and
17, where the measured peak runoff intensity exceeded the rated hydraulic capacity of the
Vortechs.
Sediment: Table 5-5 summarizes results for the SOL calculations. When every qualified event is
used in the calculations, the SOL analyses indicate a TSS reduction of 18%, an SSC reduction of
58%, and a TDS reduction of-130%. When events 8 and 17 are omitted from the calculations,
the SOL analyses indicate a TSS reduction of 35%, an SSC reduction of 61%, and a TDS
reduction of-130%. During event 8, there was a negative removal efficiency for both TSS and
SSC, however, during event 17 there was a positive removal efficiency for SSC. The difference
in TSS versus SSC is likely due to the particle size distribution in the runoff, as discussed in
5.1.1. The improvement in the TSS and SSC SOL reduction when events 8 and 17 are omitted
suggest that the Vortechs is ineffective or may resuspend sediment when it encounters flows
exceeding its rated hydraulic capacity. Since TSS showed a higher change than SSC in SOL
reduction, it appears that higher flows allow a greater proportion of fine sediment to pass from
the system. The TDS SOL reduction was -120%, however the vendor made no claims for TDS
removal.
Nutrients: The SOL data for nutrients are summarized in Table 5-6. When every qualified event
is used in the calculations, the SOL analyses indicate a total phosphorus reduction of 9.3% and
no reduction of dissolved phosphorus. When events 8 and 17 are omitted from the calculations,
the SOL analyses indicate a total phosphorus reduction of 21% and a dissolved phosphorus
reduction of 26%.
26
-------
Table 5-5. Sediment Sum of Loads Results
TSS
SSC
TDS
Event Runoff Volume
No. (ft3)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Sum of the
all events
Reduction
847
795
717
665
847
518
156
588
268
138
613
311
216
69
311
259
2,510
449
loads -
efficiency (%)
Sum of the loads -
events except 8 & 17
Reduction efficiency (%)
Inlet Outlet
(Ib) (Ib)
4.2
5.5
4.0
4.6
2.5
6.1
3.0
2.0
0.77
1.1
3.7
3.1
3.6
0.47
1.4
1.6
12
2.2
62
18
48
35
4.6
1.9
1.3
2.9
3.4
3.2
1.2
5.5
0.55
0.34
3.2
2.7
1.2
0.47
0.81
1.5
14
1.9
51
31
Inlet Outlet
(Ib) (Ib)
4.8
7.9
4.4
5.0
2.6
9.4
5.4
2.9
0.95
1.2
4.2
3.5
3.9
0.56
1.5
2.1
34
23
120
58
80
61
4.5
1.8
1.2
2.9
3.4
3.2
0.97
5.5
0.43
0.29
3.2
2.7
1.2
0.47
0.8
1.5
14
2.2
50
31
Inlet Outlet
(Ib) (Ib)
2.9
5.0
3.6
3.6
ND
3.9
2.8
0.92
1.4
0.95
2.1
3.5
2.2
0.52
1.6
1.3
ND
1.7
38
-120
37
-110
4.4
5.9
2.7
7.5
ND
5.8
3.8
3.5
4.0
1.1
5.0
16
7.1
6
2.8
1.9
ND
4.2
82
78
ND: Not determined.
27
-------
Table 5-6. Nutrient Sum of Loads Results
Event
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Sum of the
all events
Reduction
Runoff
Volume (ft3)
847
795
717
665
847
518
156
588
268
138
613
311
216
69
311
259
2,510
449
loads -
efficiency (%)
Sum of the loads -
events except 8 & 17
Reduction efficiency (%)
Total
Inlet
(g)
1.5
5.2
1.7
3.2
2.4
5.1
3.0
1.8
0.99
0.7
2.4
1.1
1.1
0.31
1.1
1.1
7.0
2.9
43
34
phosphorus
Outlet
(g)
1.9
2.7
0.83
2.3
3.1
4.0
2.1
3.3
1.1
0.47
3
1.2
0.54
0.33
1.1
1.0
7.8
1.8
39
9.3
27
21
Dissolved
Inlet
(g)
0.34
2.5
0.32
0.55
0.91
1.4
1.1
0.53
0.55
0.21
0.73
0.18
0.1
0.11
0.51
0.27
1.7
0.53
13
10
phosphorus
Outlet
(g)
0.46
1.3
0.14
0.43
0.67
0.48
0.66
0.4
0.23
0.19
1.9
0.15
0.055
0.037
0.25
0.088
5.0
0.38
13
0
7.4
26
28
-------
Metals: The SOL data for metals are summarized in Table 5-7. When every qualified event is
used in the calculations, the SOL analyses indicate a total copper reduction of 25%, a dissolved
copper reduction of-10%, a total zinc reduction of 16%, and a dissolved zinc reduction of -24%.
When events 8 and 17 are omitted from the calculations, the SOL analyses indicate a total copper
reduction of 33%, a dissolved copper reduction of -12%, a total zinc reduction of 24%, and a
dissolved zinc reduction of-21%.
Water quality parameters: The SOL data for water quality parameters are summarized in Table
5-8. When every qualified event is used in the calculations, the SOL analyses indicate a total
magnesium reduction of 42%, a total calcium reduction of 21%, and a COD reduction of-100%.
When events 8 and 17 are omitted from the calculations, the SOL analyses indicate a total
magnesium reduction of 47%, and a total calcium reduction of 22%, and a COD reduction of
-190%. When event 4 (with an apparently outlying outlet COD concentration) is taken out of the
data set, the COD reduction is -15% for all events, and 0% when events 8 and 17 are omitted
from the calculations.
Discussion: The calculated SOL reduction for TSS, SSC, total and dissolved phosphorus, COD,
and total metals improved when omitting the two events where the peak runoff intensity
exceeded the rated flow capacity of the Vortechs, while dissolved-phase constituents other than
dissolved phosphorous showed relatively little change. The data suggest that scouring or
resuspension may have occurred as a result of the high peak flow rates encountered during
events 8 and 17.
29
-------
Table 5-7. Metals Sum of Loads Results
Event
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Runoff Volume
(ft3)
847
795
717
665
847
518
156
588
268
138
613
311
216
69
311
259
2,510
449
Sum of loads -
all events
Reduction
efficiency (%)
Sum of loads -
events except 8 & 17
Reduction
efficiency (%)
Total
Inlet
(g)
0.6
1.4
0.59
1.1
0.62
1.5
1.2
0.58
0.20
0.30
0.89
0.56
0.61
0.041
0.36
0.40
2.6
2.5
16
13
copper
Outlet
(g)
0.82
0.54
0.26
0.98
0.79
1.1
0.53
1.1
0.25
0.12
0.89
0.64
0.26
0.07
0.34
0.34
2.0
0.76
12
25
8.7
33
Dissolved
Inlet
(g)
0.13
0.32
0.16
0.30
0.24
0.48
0.32
0.15
0.20
0.29
0.21
0.11
0.086
0.049
0.11
0.12
0.53
0.17
4.0
-10
3.3
-12
copper
Outlet
(g)
0.21
0.25
0.11
0.36
0.31
0.47
0.15
0.17
0.25
0.13
0.73
0.14
0.073
0.084
0.17
0.10
0.55
0.13
4.4
3.7
Total zinc
Inlet
(g)
2.9
6.1
3.2
4.1
2.4
5.4
4.1
2.5
0.91
0.94
3.1
2.1
2.5
0.47
1.7
1.8
9.2
3.4
57
16
45
24
Outlet
(g)
3.8
2.9
1.7
3.2
3.1
3.7
2.3
4.5
0.99
0.39
3.3
2.5
1.2
0.61
1.3
1.2
9.2
2.2
48
34
Dissolved zinc
Inlet
(g)
1.1
2.3
1.3
1.5
1.0
1.8
1.5
0.7
0.13
0.19
0.82
0.31
0.52
0.21
0.47
0.44
2.3
0.64
17
14
Outlet
(g)
1.6
1.8
0.97
1.8
1.5
1.6
1.5
1.2
0.61
0.13
3.0
0.54
0.36
0.31
0.62
0.49
2.7
0.66
21
-24
17
-21
30
-------
Table 5-8. Water Quality Parameters Sum of Loads Results
Total magnesium Total calcium
Event Runoff Volume
No. (ft3)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Sum of loads -
all events
847
795
717
665
847
518
156
588
268
138
613
311
216
69
311
259
2,510
449
Inlet
(Ib)
0.45
0.45
0.32
0.31
0.2
0.65
0.18
0.17
0.062
0.066
0.27
0.21
0.28
0.032
0.099
0.11
1.5
0.64
6.0
Reduction efficiency (%)
Sum of loads -
events except 8 & 17
Reduction efficiency (%)
4.3
Outlet
(Ib)
0.34
0.15
0.1
0.22
0.28
0.25
0.082
0.34
0.053
0.024
0.21
0.19
0.092
0.034
0.06
0.094
0.81
0.14
3.5
42
2.3
47
Inlet
(Ib)
1.1
1.2
0.89
0.75
0.5
1.6
0.44
0.37
0.25
0.17
0.65
0.56
0.63
0.086
0.25
0.26
3.0
1.3
14
11
Outlet
(Ib)
0.95
0.69
0.42
0.95
1.1
1.0
0.32
0.73
0.32
0.13
0.65
0.62
0.32
0.19
0.23
0.26
1.9
0.48
11
21
8.6
22
COD
Inlet
(Ib)
1.4
3.4
2.6
NC
1.9
4.2
3
1.1
0.87
0.77
2
1.5
1.3
0.31
1.2
0.92
5.2
2.2
34
28
Outlet
(Ib)
2.1
3.4
1.1
NC
3.2
3.9
2.1
3.1
1.4
0.47
3.1
1.6
0.74
0.6
1.1
0.9
8
2.4
39
-15
28
0
NC: Not calculated; outlet COD sample for event 4 was an apparent outlier (see Table 5-4).
5.2 Particle Size Distribution
Particle size distribution analysis was completed on selected events. The ability of the lab to
conduct the specific analysis depended on the available sample volume, the sediment
concentration, and the particle sizes in the sample. The ISCO samplers did not always collect an
adequate volume of sample to conduct the full suite of particle size analyses. Two types of
analyses were conducted.
-------
1. A "sand/silt split" analysis determined the percentage of sediment (by weight) larger than
62.5 |im (defined as sand) and less than 62.5 jim (defined as silt). This analysis was
performed on the inlet and outlet samples of events 2, 5, 7, 8, 9, 10, 11, and 16.
2. A Visual Accumulator (VA) tube analysis (Fishman et al., 1994) defined the percentage
of sediment (by weight) sized less than 1000, 500, 250, 125, and 62 |im. The analyses
were conducted on the inlet samples of events 2, 7, 11, and 16.
The particle size distribution results are summarized in Table 5-9. In each event where particle
size analysis was conducted, the outlet samples had a higher percentage of particles in the silt
category (<62.5 um) than the equivalent inlet sample. This is a result of the gravitational
separation treatment mechanism of the Vortechs removing a higher percentage of the larger,
heavier sediment 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, summarized in
Table 5-10, shows that the Vortechs was highly effective in removing sand particles, and that the
mass of silt particles in the inlet was nearly five times higher than the mass of sand. Particle size
distribution is affected by such things as site conditions and use, maintenance (e.g. street
sweeping), and weather. The data also show that the highest mass of silt in the outlet occurred
during event 8, when the Vortechs encountered peak flow intensities at a rate higher than its
rated flow capacity. Additionally, the Vortechs is generally more effective in removing silt
particles during events with lower treatment volumes.
Table 5-9. Particle Size Distribution Analysis Results
Percent Less Than Particle Size (um)
Event
No.
2
5
7
8
9
10
11
16
Location <1000 <500 <250 <125
Inlet 100 96 83 79
Outlet
Inlet
Outlet
Inlet 100 100 93 85
Outlet
Inlet
Outlet
Inlet
Outlet
Inlet
Outlet
Inlet 100 99 98
Outlet
Inlet 98 92 86
Outlet
<62.5 <31 <16 <8 <4 <2
76
95
42
98
81 74 67 55 43 28
98
74
98
64
94
83
98
98 97
100
83
97
32
-------
Table 5-10. Particle Size Distribution SOL Results
SSC Cone. Sands (>62.5 urn) Fines (<62.5 urn)
Event
No.
2
5
7
8
9
10
11
16
Volume
(ft3)
795
847
156
588
268
138
613
259
Inlet
(mg/L)
160
50
550
79
57
140
110
130
Outlet
(mg/L)
36
64
100
150
26
34
83
92
Inlet
(%)
24
58
2
26
36
17
2
17
Outlet
(%)
5
2
19
2
6
2
0
3
Inlet
(%)
76
42
81
74
64
83
98
83
Outlet
(%)
95
98
98
98
94
98
100
97
Sum of loads (all events)
Removal
efficiency
(percent)
Sum of loads (all events except
Removal
efficiency
(percent)
event 8)
Sand SOL
Inlet
Ob)
1.9
1.5
1.0
0.75
0.34
0.20
0.08
0.36
6.2
5.4
Outlet
(Ib)
0.09
0.07
0.02
0.11
0.03
0.01
0.00
0.04
0.36
94
0.25
95
Silt SOL
Inlet
(Ib)
6.0
1.1
4.3
2.1
0.61
1.0
4.1
1.7
21
19
Outlet
(Ib)
1.7
3.3
0.95
5.4
0.41
0.29
3.2
1.4
17
21
11
41
33
-------
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 C.
6.1 Laboratory/Analytical Data QA/QC
6,1.1 Bias (Field Blanks)
Field blanks were collected at both the inlet and outlet samplers on two separate occasions to
evaluate the potential for sample contamination through the entire sampling process, including
automatic sampler, sample-collection bottles, splitters, and filtering devices. "Milli-Q" reagent
water was pumped through the automatic sampler, and collected samples were processed and
analyzed in the same manner as event samples. The first field blank was collected on June 30,
2003 (between event 6 and 7). The second field blank was collected on May 3, 2004 (between
events 14 and 15).
Results for the field blanks are shown in Table 6-1. All but four analyses were below the limits
of detection (LOD). Of the four analyses above the LOD; only one was greater than the LOQ.
This analysis was a COD analysis conducted on the second blank test at the outlet location.
Field notes and lab notes do not note any unusual circumstances or reasons for a possible
contamination of this sample. These results show a good level of contaminant control in the
field procedures was achieved.
Table 6-1. Field Blank Analytical Data Summary
Parameter
Units
Blank 1
(06/30/03)
Inlet Outlet
Blank 2
(05/03/04)
Inlet Outlet
LOD LOQ
TDS
TSS
ssc
Calcium, total
COD
Copper, total
Copper, dissolved
Magnesium, total
Phosphorus, total
Phosphorus, dissolved
Zinc, total
Zinc, dissolved
mg/L
mg/L
mg/L
mg/L
mg/L
ug/L
ug/L
mg/L
mg/L
mg/L
ug/L
ug/L
<50
<2
<2
<0.2
<9
<1
1.7
<0.2
<0.005
<0.005
<16
<16
<50
<2
<2
<0.2
<9
<1
1.7
<0.2
<0.005
<0.005
<16
<16
<50
<2
<2
<0.2
<9
2
1.6
<0.2
<0.005
<0.005
<16
<16
<50
<2
<2
<0.2
55
1
<1
<0.2
<0.005
<0.005
<16
<16
50
2
2
0.2
9
1
1
0.2
0.005
0.005
16
16
167
7
7
0.7
28
3
3
0.7
0.016
0.016
50
50
34
-------
6.1.2 Replicates (Precision)
Precision measurements were performed by the collection and analysis of duplicate samples.
The relative percent difference (RPD) recorded from the sample analyses was calculated to
evaluate precision. RPD is calculated using the following formula:
\X\- X2\
%RPD = - x 100%
where:
xi = Concentration of compound in sample
x_2 = Concentration of compound in duplicate
x = Mean value of xi and X2
Field precision: Field duplicates were collected to monitor the overall precision of the sample
collection procedures. 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.
Overall, the results show good field precision. Below is a discussion on the results from selected
parameters.
TSS and SSC: Results were within targeted limits. Outlet samples (lower concentrations and
smaller particle sizes) showed higher precision. The poorer precision for the inlet samples could
be due to the sample handling and splitting procedures, or sampling handling for analysis, or a
combination of factors. Tests on the sample splitting capabilities of a churn splitter showed the
bias and the precision of the splits is compromised with increasing sediment concentrations and
particle size. The tests identified the upper particle size limits for the churn splitter is between
250 and 500 |im (Horowitz, et al, 2001).
Dissolved constituents (sediment phosphorus, and metals): These parameters consistently had
very low RPD (very high precision). This supports the idea that the sample splitting operation
may be the source of higher RPD in the high particulate samples.
Total metals: The total copper, total magnesium, and total zinc data had RPD values exceeding
the targeted limits. Similar to the paniculate sediment results, the highest RPDs occurred in the
inlet samples, which had higher particulate concentrations; however, total copper had high RPDs
for the outlet samples as well. The total calcium data showed higher precision.
Total phosphorus: This parameter was consistently below or near the acceptable RPD value of
30%. Again, the highest discrepancies occurred at the inlet analyses, with very good duplicate
agreement at the outlet samples.
35
-------
Table 6-2. Field Duplicate Sample Relative Percent Difference Data Summary
6/27/03 9/12/03
8/24/04
Parameter
TDS
TSS
ssc
COD
Calcium, total
Copper, total
Copper, dissolved
Magnesium, total
Phosphorus, total
Phosphorus, dissolved
Zinc, total
Zinc, dissolved
Unit
mg/L
mg/L
mg/L
mg/L
mg/L
ug/L
ug/L
mg/L
mg/L
mg/L
ug/L
Ug/L
Inlet
Outlet
Inlet
Outlet
Inlet
Outlet
Inlet
Outlet
Inlet
Outlet
Inlet
Outlet
Inlet
Outlet
Inlet
Outlet
Inlet
Outlet
Inlet
Outlet
Inlet
Outlet
Inlet
Outlet
Rep la
120
180
190
100
260
110
130
110
38
30
110
76
32
33
15
7.4
0.34
0.27
0.1
0.03
360
240
110
110
Rep
Ib
120
180
190
100
290
100
130
120
48
31
100
75
33
32
20
7.7
0.35
0.27
0.1
0.03
370
250
120
110
RPD
0
0
0
0
11
10
0
9
23
3
10
1
3
3
29
4
3
0
0
0
3
4
9
0
Rep
la
280
390
310
94
500
98
360 3
240
48
32
200
160
75
35
20
8.3
0.73
0.49
0.24
0.15
960
520
340
320
Rep
Ib
290
390
i
120
550
100
310
220
45
33
280
120
73
35
19
8.4
0.68
0.48
0.24
0.15
920
520
350
330
RPD
4
0
4
10
2
15
9
9
3
33
29
3
0
5
1
7
2
0
0
4
0
3
3
Rep
la
54 2
130 2
60
70
73
970
75
53
84 3
66
17 84
110
35
13
9.9
32
4.9
0.20
0.14
0.04
0.03
350
150
51
49
Rep
Ib
2
150 2
78
69
820
79
78 3
3
48
17
200
60
13
10
23
5
0.23
0.14
0.04
0.03
270
170
50
52
RPD
11
14
11
6
17
5
38
0
32
0
58
53
0
1
33
2
14
0
0
0
26
13
2
6
Limit
30
30
ND
ND
25
25
25
25
30
30
25
25
1 Lab error; no result reported
2 Laboratory duplicate sample QA/QC objective exceeded for this batch of samples.
3 Holding time exceeded
ND not determined
36
-------
Laboratory precision: The WSLH 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.
Table 6-3. Laboratory Duplicate Sample Relative Percent Difference Data Summary
Average Maximum Minimum Std. Dev.
Parameter1 Count2
TDS
TSS
Calcium, total
Copper, total
Copper, dissolved
Magnesium, total
Phosphorus, total
Phosphorus, dissolved
Zinc, total
Zinc, dissolved
16
19
15
16
16
15
21
15
13
15
4.3
2.2
1.7
1.7
2.0
1.3
1.3
0.14
2.6
2.0
18
8.6
4.1
5.5
6.5
4.7
7.9
1.6
8.1
6.9
0.00
0.00
0.13
0.09
0.07
0.01
0.00
0.00
0.00
0.04
4.5
2.5
1.0
1.6
2.1
1.3
1.9
0.4
2.4
1.9
1 Laboratory precision may also be evaluated based on absolute difference between duplicate
measurements when concentrations are low. For data quality objective purposes, the absolute
difference may not be larger than twice the method detection limit.
2 Analyses where both samples were below detection limits were omitted from this evaluation.
The data show that laboratory precision was maintained within target limits throughout the
course of the verification project.
The field and analytical precision data combined suggest that the solids load and larger particle
sizes in the inlet samples are the likely cause of poor precision, and apart from the field sample
splitting procedures for inlet samples, the verification program maintained high precision.
6.1.3 Accuracy
Method accuracy was determined and monitored using a combination of matrix spike/matrix
spike duplicates (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. Accuracy was in control throughout the
verification test. Tables 6-4 and 6-5 summarize the matrix spikes and lab control sample
recovery data, respectively.
37
-------
Table 6-4. Laboratory MS/MSD Data Summary
Parameter
Average Maximum Minimum Std. Dev. Range
Count
Calcium, total
Copper, total
Copper, dissolved
Magnesium, total
Phosphorus, total
Phosphorus, dissolved
Zinc, total
Zinc, dissolved
16
15
16
16
20
16
16
15
98
98
101
99
103
101
97
97
113
116
116
102
109
106
103
105
94
86
92
97
97
97
91
93
4.7
8.6
6.5
1.5
3.2
2.5
3.2
3.3
80-120
80-120
80-120
80-120
70-130
70-130
80-120
80-120
Table 6-5. Laboratory Control Sample Data Summary
Mean Maximum Minimum Std. Dev.
Parameter
Count
Total calcium
Total copper
Dissolved copper
Total magnesium
SSC
TSS
Dissolved phosphorus
TDS
Total phosphorus
Total zinc
Dissolved zinc
13
27
7
13
15
15
11
15
16
16
4
97
100
101
97
99
100
101
105
101
98
96
105
106
106
103
108
117
107
118
106
103
98
91
91
92
92
87
89
97
98
96
95
94
3.6
3.9
4.5
3.1
5.6
7.9
2.9
6.1
2.4
2.3
1.7
The balance used for solids (TSS, TDS, and total solids) 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
a NIST traceable thermometer.
6.1.4 Representativeness
The field procedures were designed to ensure that representative samples were collected of both
inlet and outlet stormwater. Field duplicate samples and supervisor oversight provided assurance
38
-------
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.
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.
Regarding flow (velocity and stage) measurements, representativeness is achieved in three ways:
1. The meter was installed by experienced USGS field monitoring personnel familiar
with the equipment, in accordance with the manufacturer's instructions;
2. The meter's individual area and velocity measurements were converted to a
representation of the flow area using manufacturer's conversion procedures (see
Chapter 9 of Marsh-McBirney's O&M Manual in Appendix A of the test plan);
3. The flow calculated from the velocity/stage measurements was calibrated using the
procedure described in Section 6.2
To obtain representativeness of the sub-samples (aliquots) necessary to analyze the various
parameters from the event sample, a churn splitter was used. As noted in Radtke, et al. (1999),
the churn splitter is the industry standard for splitting water samples into sub-samples. However,
inconsistencies were noted in the sub-samples, especially when the sample contained high
concentrations of large-sized sediments. The even distribution of the larger particulates becomes
problematic, even with the agitation action of the churn within the splitter. The issue of the
potential for uneven distribution of particulates has not been fully resolved. (Horowitz, et al,
2001).
6.1.5 Completeness
The flow data and analytical records for the verification study are 100% complete. There were
instances of velocity "dropouts" during some events. A discussion of the calibration procedures
for flow data (velocity and stage measurements), including how velocity dropouts were
addressed, is provided in Section 6.2.
6.2 Flow Measurement Calibration
6.2.1 Stage Measurement Corrections
Static gauge height measurements were made at the inlet pipe by constricting the pipe to a
steady-state water level. An inflatable ball was used to block the pipe. Water level readings
from a measuring tape inside the pipe were compared to the water surface level recorded by the
39
-------
flow meters (located within the inlet pipe,). Gauge heights were checked thirteen times during
the project. A gauge height correction curve with three gauge height points—bottom, middle,
and top (approximately 0.0 ft, 0.3 ft, and 0.6 ft above the invert pipe elevation)—was developed
for the pipe, as shown in Table 6-6. Most of the correction factors for the inlet lowered the
recorded gauge height by approximately 5%. Corrections for the outlet pipe were also small
(less than ± 2%).
Table 6-6. Stage Height Corrections
Gauge Height:
Low
Gauge
Height Correction
Date (ft) (unitless)
Gauge Height:
Medium
Gauge
Height Correction
(ft)(ft)
Gauge Height:
High
Gauge
Height Correction
(ft)(ft)
2/20/03
4/11/03
4/11/03
8/20/03
8/20/03
8/25/03
8/25/03
8/26/03
8/26/03
11/4/03
11/5/03
3/9/04
3/9/04
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0.01
0.01
-0.002
-0.002
0.061
0.061
-0.052
-0.052
-0.003
-0.003
0.006
0.417
0.417
0.35
0.35
0.29
0.29
0.29
0.29
0.29
0.29
0.35
0.35
0.31
-0.083
-0.083
-0.03
-0.03
0.04
0.04
0.059
0.059
-0.009
-0.009
0.011
0.011
0.002
0.635
0.63
0.635
0.635
0.4
0.4
0.4
0.4
0.4
0.4
0.69
0.69
0.63
-0.017
-0.017
-0.07
-0.07
0.05
0.05
0.056
0.056
-0.004
-0.004
0.02
0.02
0.012
6.2.2 Flow Calibration — Inlet Flume Measurements
Flow meters at the inlet and outlet of the Vortechs were calibrated on April 18, 2003 and
November 8, 2003 using similar procedures. A 3-in. Parshall flume attached to 2.5 ft width by
8 ft length by 2 ft depth chamber was mounted in the bed of a boom truck. Hydraulics on the
boom truck was used to level the flume. Water was pumped from the Milwaukee River into the
chamber minimizing flow turbulence in the approach section of the flume. Four different
pumping rates were used to calibrate the flow meters. A 2-in. pump generated discharge rates of
approximately 0.1 and 0.15 cfs, a 4-in. pump generated discharge rate of approximately 0.4 cfs
and the two pumps together generated approximately 0.55 cfs. Flow from the flume was
discharged through a 6-in. corrugated pipe upstream of the installed area-velocity meters. Water
level in the flume was measured and discharge for the 3-in. Parshall flume was recorded. A 10
to 20 min pumping test was run for each rate and pertinent information from the meters was
recorded manually from the CR10 data logger.
Several steps were needed to correct each area-velocity meter flow using raw data. First, meters
outputted point velocity, which was converted to an average area velocity by applying an
equation created by the manufacturer. Overall, this decreased flows by an average of 10%.
Second, the area of the pipe was reduced to the portion of the flowing pipe by subtracting the
40
-------
meter and cord area; this could be as much as half of the area at depth less then 0.1 ft. Flows
were then calculated by multiplying the average velocity by the effective-cross-sectional area
based on the water level. Because the velocity dropouts occurred at low and high flows the
velocities from the meter were used only to assist in developing the flow rating described below.
6.2. 3 Developing the Rating Curve
Discharge was estimated for each meter after gage height corrections were applied, then
corrected stage values and flume discharges were plotted. Using this plot, a stage vs. discharge
rating was developed that tracked through the flume-recorded points at gage heights ranging
from 0.08 to 0.20 ft. The following USGS rating curve for stable channels was used, which is a
modified form of Manning's equation (Ratz, 1982):
2n
where:
Q = discharge
C = discharge coefficient
G = gage height of the water surface
e = effective zero control
S = energy slope loss
n = Manning's roughness coefficient
Flows were estimated using Manning's equation where flume discharge was not available.
Calibration data was not available at low flows (less than 0.08 ft.) because the velocities did not
register until the meter was submerged or at high flows (greater than 0.20 ft, or 0.55 cfs) because
this exceeded the calibration pumping rate capabilities. Manning's roughness coefficient was
adjusted to fit the USGS rating curve for low flows and Manning's roughness coefficient was
adjusted to fit the calibrated rating curve and corrected meter flow.
The Manning's rating curve is expressed by the following equation:
Q = (\A86/n)AR2/3Sl/2 (6-3)
where:
1.486 converts to English units
A = cross-sectional area based on the water level
R = hydraulic radius based on the water level
S = energy slope loss
Figure 6-1 shows the rating curve developed as a result from this process.
41
-------
0.75
Low
High
Flume Calibrated
Actual Flume Points
High Flow Meter Points
0.10
0.05
0.00
0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.20 2.40 2.60 2.80 3.00 3.20 3.40 3.60
Discharge (cfs)
Figure 6-1. Calculated rating curve for Vortechs inlet site.
6.2.4 Outlet Volume Comparison
This Vortechs configuration did not have an external bypass mechanism, so the calculated inlet
and outlet event volumes should be the same, and a comparison of the calculated inlet and outlet
volumes can be used to ensure both flow monitors worked properly. However, the outlet site
area velocity meter experienced frequent problems. Because of these problems, a comparison of
inlet and outlet volumes was not conducted as part of the QA/QC process.
6.2.5 Comparison of Runoff Volumes: Rainfall Depth vs. Inlet Measurements
A final comparison of instrument measurements was to compare the measured rainfall depth
over the drainage area to the runoff volume calculated at the inlet meter. The rational method
was used to convert rainfall depth to runoff volume. The rational method is expressed by the
following equation:
Q = CIA
(6-4)
where:
Q = Total Flow Volume (ft3)
C = Runoff Coefficient (dimensionless)
/ = Rainfall Depth (ft)
A = Drainage Basin Area (ft2)
42
-------
This data is summarized in Table 6-7. The runoff coefficient was 1 (since the entire surface is
paved) and the drainage basin area is 10,890 ft2 (0.25 acres).
Table 6-7. Comparison of Runoff Volumes
Event Runoff Volume (ft)
Event
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Date
4/30/03
5/4/03
5/9/03
5/30/03
6/8/03
6/27/03
9/12/03
9/14/03
10/14/03
10/14/03
10/24/03
3/25/04
3/28/04
4/17/04
5/12/04
5/20/04
8/3/04
8/24/04
Based on
Rainfall
Depth
998
653
790
490
563
517
272
427
245
209
644
771
790
218
499
218
1,630
771
Based on Percent
Inlet difference
Velocity (absolute
Meter value)
847
795
717
665
847
518
156
588
268
138
613
311
216
69
311
259
2,510
449
Average
Median
Maximum
Minimum
Std. Dev.
15
22
9.2
36
51
0.1
43
38
9.4
34
4.9
60
73
68
38
19
54
42
34
37
73
0.1
22
The comparison shows that calculations for seven of the eighteen events are within 25% of each
other. The rest of the events showed greater differences. There are several possibilities for
differences in these readings including:
• Inherent accuracy of each instrument (rain gauge and velocity meter).
• Accuracy of the drainage area delineation. As stated previously, the drainage area was
calculated from WisDOT design drawings and maintenance update documents (see
Section 3.1). It is likely that the actual contributing area for each event varies depending
43
-------
on the rain depth, intensity, and duration. Small features in the highway decking (joints,
cracks, etc.) will affect the drainage characteristics.
• Inlet capacity may also affect the volume of rainfall entering the storm sewer system.
6.2.6 Point Velocity Correction
Equations have been developed by the flow monitoring equipment manufacturer to correct for
velocity measurements recorded at a single point. A point velocity can be different than the
average velocity over the entire depth of the water in the pipe. The equation for the flow
equipment lowered all the measured velocities by approximately 10%.
44
-------
Chapter 7
Operations and Maintenance Activities
7.1 System Operation and Maintenance
Vortechs recommends inspecting the system on a quarterly basis. The main point of the
inspection is to check that the sediment and debris trapped in the grit chamber (see Figure 2-1)
does accumulate any higher than to within 6 inches of the dry weather standing water elevation.
The dry-weather standing water elevation was about three feet from the bottom of the grit
chamber. Inspections conducted by the TO and the USGS never found the accumulation of
sediment and debris in the grit chamber to reach this level.
The TO followed the manufacturer's guidelines for maintenance on the Vortechs system during
the verification testing. Installation of the Vortechs was completed in December 2001. In the
spring of 2002 the monitoring equipment was installed and initial monitoring began. Over the
summer and fall of 2002, the inlet velocity meter and area around the inlet sampling intake was
frequently inundated with sediment from the backwater effects of the Vortechs. It was decided
to re-configure the inlet pipe system and move the velocity meter and sampling intake line above
this backwater area. This allowed for better measurements. The pipe reconfiguration was
completed in January 2003. No events monitored in 2002 were used for the verification
evaluation. In the spring of 2003, the system was placed into operation and adjustments to the
system were completed, ETV monitoring of the system began in April 2003. Table 7-1
summarizes O&M activities undertaken by the TO and USGS once verification testing was
initiated.
Table 7-1. Operation and Maintenance During Verification Testing
Date
Activity
Personnel Time/Cost
4/18/03
04/29/03
11/08/03
USGS conducted velocity meter/flow
measurement calibration. Sediment in Vortechs
grit chamber observed at depths ranging from
less than 1 inch to 2.5 inches.
General Pipe Services jet-vac and vacuumed out
Vortechs grit chamber (pre-monitoring
cleanout).
USGS conducted velocity meter/flow
measurement calibration.
2 USGS staff® 12
hours each, (most
time spent on
calibration work; less
than 1 hour for
checking Vortechs
l/2 day invoice =
$985.00. Landfill fee
for waste = $263.13
No maintenance
conducted
45
-------
Table 7-1 (cont'd)
Date
Activity
Personnel Time/Cost
05/07/04
08/30/04
09/09/04
09/24/04
Vortechs inspection by Earth Tech; measured
sediment depth in grit chamber. Sediment
relatively evenly distributed throughout
chamber. Depths ranged from 1 to 2 in.
Floatables covered about 5 - 10% of the surface.
Oil sheen also observed.
USGS inspected Vortechs and measured
sediment depth in grit chamber. Measured
depths ranged from 1 to 5.5 in. Water in
chamber cloudy; sediment very soft and organic,
not much sand or gravel. Very little floatables
observed.
Earth Tech inspected Vortechs; measured
sediment depth in grit chamber. Depths ranged
from 0 to 5.75 in. Also observed oil sheen and
floatables in chamber. Outlet chamber also
inspected, with a very thin layer of sediment
observed. Some scum and oil observed in this
chamber.
Post monitoring clean out of Vortechs. Clean
out conducted by Earth Tech, WDNR and
USGS. A complete description of the process
and results is presented in Section 7.2.
2 staff @ 2 hours
each.
1 staff @ 1 hour.
2 staff® 1 '72 hours
each.
4 staff @ 8 hours
each (time
commitment to
capture all sediment
and debris for drying
and analysis).
7.2 Description of Post Monitoring Cleanout and Results
7.2.1 Background
On September 24, 2004, the Vortechs was cleaned out so that as much of the solid material as
possible from the device could be dried, weighed, and characterized. The weather was sunny
and clear, with temperatures in the low 70s, and there had been no rain for the previous two
weeks.
The general steps followed were:
1. Take sample of standing water before any disturbance to analyze for TSS of water above
the settled material.
2. Measure the standing water depth and sediment depth in the Vortechs before any
removal of material
46
-------
3. Decant the standing water using a hand held sump pump to a level 0.5 ft above the
settled material layer.
4. Decant the next layer of water using hand held sump pump into five-gallon containers.
Obtain a water sample from each five-gallon container, composite into one container for
analysis of TSS.
5. Remove sediment from grit chamber and all accessible portions of the vault and place in
five-gallon containers.
6. Transport containers to USGS lab in Middleton, Wisconsin for drying and weighing.
7.2.2 Field Procedures
For purposes of solids and water measurements and removal, the system is divided into the
following sections (from upstream to downstream in the system):
• Inlet pipe
• Grit chamber (tank 1)
• Oil and Flow Control Chamber (tank 2)
• Outlet Chamber (tank 3)
Tanks 1 and 2 are hydraulically connected and have the same water surface elevation. Tank 3 is
hydraulically separated from the upper two tanks with an independent standing water elevation.
Standing water TSS samples:
• Grit chamber: tank 1, bottle 1
• Lower chamber: tank 3, bottle 1
Water and sediment depth measurements in grit chamber (tank 1):
• Manhole rim to top of water: 5.20 ft
• Manhole rim to top of sediment: 8.10 ft
• Manhole rim to bottom of grit chamber: 8.40ft
• Depth of water in vault: 3.20ft
• Depth of sediment in grit chamber: 0.30 ft
7.2.3 Measurement Results
Table 7-2 summarizes the results of the material analysis. The term "sediment" is avoided in this
analysis, because much of the material consisted of leaves, trash, and larger debris. The dry
weight reported includes all the debris removed. The particle size analysis was conducted only
upon the material after the larger debris was sifted out. As shown in Table 7-2, approximately
82% of the sediment retained in the sediment chamber had a particle size of 125 jim or larger.
47
-------
Table 7-2: Analysis of Vortechs Cleanout Material
Material
Dry
Percent Less Than Particle Size (urn)
Sediment Source
Weir Chamber (tank 3)
Inlet Pipe
Grit Chamber (tank 1) (1
of 2 samples)
Grit Chamber (tank 1) (2
of 2 samples)
Grit Chamber (tank 1)
average of 2 sub-
samples)
Total
yicigiii
(lb)
15
8.1
100
120
<4000
87
88
95
89
92
91
<2000
82
83
92
85
88
86
<1000
73
76
87
69
78
78
<500
54
62
75
59
67
64
<250
37
39
40
41
41
39
<125
21
18
16
20
18
18
<63
14
11
7.2
11
9
10
<31
10
6.4
5.4
8.3
6.9
7
<16
6.9
4.6
3.8
6.3
5.1
5
<8
4.4
3.5
2.6
4.3
3.5
3
<4
3.4
2.8
2.3
3.1
2.7
3
<2
2.5
2.0
1.6
2.2
1.9
2
48
-------
Chapter 8
References
1. APHA, AWWA, and WEF. Standard Methods for the Examination of Water and
Wastewater, 19thed. Washington, DC, 1995.
2. Horowitz; AJ; Hayes, T.S.; Gray; J.R.; Capel, P.D. Selected Laboratory Evaluations of the
Whole-Water Sample-Splitting Capabilities of A Prototype Fourteen-Liter Teflon* Churn
Splitter, U.S. Geological Survey Open-File Report 01-386, 2001.
3. Fishman, M. 1, 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.
4. Huff, F. A., Angel, J. R. Rainfall Frequency Atlas of the Midwest, Midwestern Climate
Center, National Oceanic and Atmospheric Administration, and Illinois State Water Survey,
Illinois Department of Energy and Natural Resources. Bulletin 71, 1992.
5. NSF International and Earth Tech, Inc. Test Plan for the Verification of. Vortechs* Model
100 Stormwater Treatment System "Riverwalk Site" Milwaukee, Wisconsin. March 22,
2004.
6. 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).
7. Radtke, D.B. et al., National Field Manual for the Collection of Water-Quality Data, Raw
Samples 5.1. U.S. Geological Survey Techniques of Water-Resources Investigations Book 9,
Chapter A5, pp 24-26, 1999.
8. United States Environmental Protection Agency. Methods and Guidance for Analysis of
Water, EPA 821-C-99-008, Office of Water, Washington, DC, 1999.
49
-------
Glossary
Accuracy - a measure of the closeness of an individual measurement or the average of a number
of measurements to the true value and includes random error and systematic error.
Bias - the systematic or persistent distortion of a measurement process that causes errors in one
direction.
Comparability - a qualitative term that expresses confidence that two data sets can contribute to
a common analysis and interpolation.
Completeness - a quantitative term that expresses confidence that all necessary data have been
included.
Precision - a measure of the agreement between replicate measurements of the same property
made under similar conditions.
Protocol - a written document that clearly states the objectives, goals, scope and procedures for
the study. A protocol shall be used for reference during Vendor participation in the verification
testing program.
Quality Assurance Project Plan - a written document that describes the implementation of
quality assurance and quality control activities during the life cycle of the project.
Residuals - the waste streams, excluding final outlet, which are retained by or discharged from
the technology.
Representativeness - a measure of the degree to which data accurately and precisely represent a
characteristic of a population parameter at a sampling point, a process condition, or
environmental condition.
Wet-Weather Flows Stakeholder Advisory Group - a group of individuals consisting of any
or all of the following: buyers and users of in drain removal and other technologies, developers
and Vendors, consulting engineers, the finance and export communities, and permit writers and
regulators.
Standard Operating Procedure - a written document containing specific procedures and
protocols to ensure that quality assurance requirements are maintained.
Technology Panel - a group of individuals with expertise and knowledge of stormwater
treatment technologies.
Testing Organization - an independent organization qualified by the Verification Organization
to conduct studies and testing of mercury amalgam removal technologies in accordance with
protocols and Test Plans.
Vendor - a business that assembles or sells treatment equipment.
50
-------
Verification - to establish evidence on the performance of in drain treatment technologies under
specific conditions, following a predetermined study protocol(s) and Test Plan(s).
Verification Organization - an organization qualified by EPA to verify environmental
technologies and to issue Verification Statements and Verification Reports.
Verification Report - a written document containing all raw and analyzed data, all QA/QC data
sheets, descriptions of all collected data, a detailed description of all procedures and methods
used in the verification testing, and all QA/QC results. The Test Plan(s) shall be included as part
of this document.
Verification Statement - a document that summarizes the Verification Report reviewed and
approved and signed by EPA and NSF.
Verification Test Plan - A written document prepared to describe the procedures for conducting
a test or study according to the verification protocol requirements for the application of in drain
treatment technology. At a minimum, the Test Plan shall include detailed instructions for sample
and data collection, sample handling and preservation, precision, accuracy, goals, and quality
assurance and quality control requirements relevant to the technology and application.
51
-------
Appendices
A Vortechs Design and O&M Guidelines
B Test Plan
C Event Hydrographs and Rain Distribution
C Analytical Data Reports with QC
52
------- |