Eastern Washington
Stormwater Effectiveness Studies
Technical Evaluation Report (TER)
Street Sweeping and Catch Basin Cleaning
Comparison
Study Classification: Operational BMPs
December 2020
Prepared For:
Jon Morrow, Stormwater Manager
City of Ellensburg
Public Works Department
501 N Anderson Street
Ellensburg, WA Zip 98926
509.925.6819
Prepared By:
Osborn Consulting, Inc.
101 S. Stevens Street, Suite 103
Spokane, WA 99201
509.867.3654
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QAPP and TER Publication Information
The project Quality Assurance Project Plan (QAPP) and the Technical Evaluation Report (TER)
will
stored
and
accessible
the
public
the
following
weblink:
https://www.ci.ellensburg.wa.us/. For questions regarding the Proposal, please contact Jon
Morrow by email [email protected] or phone 509.925.6819.
QAPP and TER Author Contact Information
Aimee Navickis-Brasch, P.E., PhD
Engineering Manager
Osborn Consulting, Inc.
101 S. Stevens Street, Suite 103
Spokane, Washington, 99201
[email protected]
509.867.3654
Taylor Hoffman, P.E.
Stormwater Research Engineer
Osborn Consulting, Inc.
101 S. Stevens Street, Suite 103
Spokane, Washington, 99201
[email protected]
509.867.3654
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Document History
The study documents were developed following the Eastern Washington (EWA) Detailed Study
Design Proposal and Quality Assurance Project Plan Template for Operational Best Management
Practices (BMPs). A copy of the template is located on the Washington Stormwater Center’s
website at the following web link: https://www.wastormwatercenter.org/ew-effectiveness-studies/
The Detailed Study Design Proposal (Proposal) was submitted to Ecology by Jon Morrow on June
28, 2017. Ecology approved the Proposal via email to Jon Morrow on November 8th, 2017.
Appendix A of the Quality Assurance Project Plan (QAPP) contains a copy of the approval letter
along with Ecology’s comments on the Proposal. Appendix B of the QAPP contains a summary
of responses to Ecology’s comments including how the comments were incorporated into QAPP.
The draft QAPP was reviewed by members of the Technical Advisory Group (TAG) in January
2018. Appendix C of the QAPP contains a summary of the TAG’s comments along with a
summary of response to these comments including how the comments were addressed in the
QAPP. The final QAPP was submitted to Ecology prior to the May 8, 2018 deadline for their
review and comment. Appendix D of the QAPP contains a copy of Ecology’s approval letter of
the QAPP and a summary of Ecology’s comments along with responses to the comments including
how the comments were incorporated into the final QAPP document. The revised version of the
QAPP was submitted on August 1, 2018.
In June 2020, the QAPP was revised as noted in the Appendix J. Summary of Revisions Table.
Generally, the revisions included updating the project schedule and the Technical Advisory Group.
The revisions were approved by Ecology in June 2020.
The study started in October 2018 and the last data was collected in April 2020. The draft
Technical Evaluation Report (TER) was presented and submitted to the TAG in July 2020 for
review and comment. The TAG comments were discussed at an August 2020 TAG meeting.
Appendix Q of the TER contains a summary of the TAG’s comments along with a summary of
response to these comments including how the comments were addressed in this document. The
final TER was submitted to Ecology in December 2020.
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Distribution List
The distribution list includes each party who will receive a copy of the TER.
Name, Title
Organization
Contact Information:
Telephone, E-mail
Jon Morrow
Stormwater Manager
City of Ellensburg
509.925.8619
[email protected]
Kathy Sattler, Laboratory
Project Manager
Anatek Laboratories
509.838.3999
[email protected]
Aimee Navickis-Brasch,
Engineering Manager
Osborn Consulting, Inc.
509.343.8515
[email protected]
Taylor Hoffman
Stormwater Engineer
Osborn Consulting, Inc.
509.343.8477
[email protected]
Jeff Wiemer, Regional
Stormwater Coordinator
Asotin County, City of
Asotin, and the City of
Clarkston
509.243.2071 ext. 1430
[email protected]
Bill Aukett, Stormwater
Program Manager
City of Moses Lake
509.764.3792
[email protected]
Trey George,
Stormwater Permit
Coordinator
City of Spokane
509.625.7908
[email protected]
Chad Philips,
Stormwater Engineer
City of Spokane Valley
509.720.5013
[email protected]
Brian Morgenroth,
Stormwater Coordinator
City of Walla Walla
509.524.4669
[email protected]
Jessica Shaw,
Utilities and Environmental
Manager
City of Wenatchee
509.888.7173
[email protected]
Andrea Jedel,
Municipal Stormwater
Permit Manager
Department of Ecology
509.575.2807
[email protected]
Karen Dinicola,
Phase 2-3a Gross Grant
Ecology Project Manager
Department of Ecology
360.407.6550
[email protected]
Doug Howie,
Reviewer Structural and
Operational BMPs
Department of Ecology
360.407.644
[email protected]
Brandi Lubliner,
Reviewer Monitoring
System Designs
Department of Ecology
360.407.7140
[email protected]
Nigel Pickering
Professor
Washington State
University
509.335.8624
[email protected]
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1.0
Table of Contents
QAPP AND TER PUBLICATION INFORMATION ……………………………………………………………………………..II
DOCUMENT HISTORY ……………………………………………………………………………………………………………………… III
DISTRIBUTION LIST ……………………………………………………………………………………………………………………………. I
1.0
TABLE OF CONTENTS …………………………………………………………………………………………………………………II
2.0
EXECUTIVE SUMMARY ………………………………………………………………………………………………………………. 4
3.0
INTRODUCTION ………………………………………………………………………………………………………………………….. 6
3.1
INTRODUCTION TO THE OPERATIONAL BMP …………………………………………………………………………………… 6
3.2
PROBLEM DESCRIPTION …………………………………………………………………………………………………………………. 6
3.3
STUDY GOALS …………………………………………………………………………………………………………………………….. 10
3.4
STUDY DESCRIPTION AND OBJECTIVES ………………………………………………………………………………………….. 10
3.5
STUDY LOCATION ……………………………………………………………………………………………………………………….. 14
4.0
OPERATIONAL BMP DESCRIPTION ……………………………………………………………………………………….. 16
5.0
SAMPLING PROCEDURES ………………………………………………………………………………………………………… 18
5.1
TYPES OF DATA COLLECTED ………………………………………………………………………………………………………… 18
5.2
SAMPLE COLLECTION PROCESS AND DESIGN(S) …………………………………………………………………………….. 20
6.0
DATA QUALITY ASSESSMENT ………………………………………………………………………………………………… 26
6.1
BIAS …………………………………………………………………………………………………………………………………………… 26
6.2
PRECISION ………………………………………………………………………………………………………………………………….. 27
6.3
REPRESENTATIVENESS …………………………………………………………………………………………………………………. 28
6.4
COMPLETENESS …………………………………………………………………………………………………………………………… 29
6.5
COMPARABILITY …………………………………………………………………………………………………………………………. 30
6.6
SENSITIVITY ………………………………………………………………………………………………………………………………… 30
7.0
RESULTS AND DISCUSSION ……………………………………………………………………………………………………. 31
7.1
SEDIMENT CHARACTERIZATION …………………………………………………………………………………………………… 31
7.2
SEDIMENT ACCUMULATION RATE ………………………………………………………………………………………………… 35
7.3
WEATHER DATA …………………………………………………………………………………………………………………………. 49
7.4
STATISTICAL COMPARISON OF DATASETS ……………………………………………………………………………………… 55
8.0 RECOMMENDATIONS AND TRANSFERABILITY …………………………………………………………………….. 57
8.0
RELATIONSHIP BETWEEN STREET SWEEPING AND CATCH BASIN CLEANING …………………………………….. 57
8.2
CONSIDERATIONS FOR TRANSFERABILITY OF RECOMMENDATIONS ………………………………………………….. 59
9.0
CONCLUSION …………………………………………………………………………………………………………………………….. 62
10.0 REFERENCES ………………………………………………………………………………………………………………………………… 63
11.0
APPENDICES ………………………………………………………………………………………………………………………….. 66
APPENDIX A SURVEY DATA ………………………………………………………………………………………………………………….. 67
APPENDIX B RAW LAB DATA ……………………………………………………………………………………………………………….. 68
APPENDIX C STREET & CATCH BASIN WEIGHT COLLECTED RAW DATA …………………………………………………… 69
APPENDIX D CATCH BASIN DEPTH RAW DATA ……………………………………………………………………………………… 70
APPENDIX E SUMP SOCK TARE WEIGHTS RAW DATA ……………………………………………………………………………… 71
APPENDIX F SIEVE ANALYSIS SUMMARY DATA ………………………………………………………………………………………. 72
APPENDIX G ORGANIC CONTENT & MOISTURE CONTENT SUMMARY ………………………………………………………. 73
APPENDIX H STREET SWEEPER SEDIMENT DATA SUMMARY …………………………………………………………………….. 74
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APPENDIX I CATCH BASIN SEDIMENT WEIGHT SUMMARY ………………………………………………………………………. 75
APPENDIX J CATCH BASIN DEPTH SUMMARY …………………………………………………………………………………………. 76
APPENDIX K CATCH BASIN SOCK SEDIMENT DATA SUMMARY ………………………………………………………………… 77
APPENDIX L WEATHER DATA DURING STUDY ……………………………………………………………………………………….. 78
APPENDIX M AUDIT RESULTS ……………………………………………………………………………………………………………….. 79
APPENDIX N EQUIPMENT MAINTENANCE RECORDS ………………………………………………………………………………. 80
APPENDIX O RELATIVE PERCENT DIFFERENCE RESULTS ………………………………………………………………………….. 81
APPENDIX P STATISTICAL ANALYSIS RESULTS ………………………………………………………………………………………… 82
APPENDIX Q TAG TER COMMENTS & RESPONSES TO COMMENTS ………………………………………………………….. 83
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2.0
Executive Summary
Street sweeping and catch basin cleaning are operational best management practices (BMPs) that
are known to reduce the transport of sediment to receiving water bodies. In the EWA National
Pollutant Discharge Elimination System (NPDES) Municipal Separate Storm Sewer System Phase
II Permit (MS4 Permit), catch basin cleaning is a required operations and maintenance (O&M)
practice. The permit-required frequency of catch basin inspections (and potential cleanings)
increased on December 31, 2018. Meeting these requirements creates a logistical and financial
challenge for some EWA permittees due primarily to winter climate conditions which can prohibit
catch basin cleaning for four months of the year. More frequent street sweeping may provide a
solution to meeting the new permit requirements. Specifically, studies have shown that street
sweeping can reduce the amount of sediment transported to catch basins during rainfall events. In
theory, this could reduce the accumulation rate of sediment in catch basins and subsequently the
frequency of which catch basins need to be cleaned.
The goals for this study were to 1) investigate whether the frequency of street sweeping
significantly influenced sediment accumulation in catch basins (and transport from catch basins)
during the dry season in a semiarid location, 2) recommend a combination of street sweeping and
catch basin cleaning procedures for achieving permit requirements for catch basin cleaning, and
3) use the study results to justify a condition in the next permit for O&M procedures that allows
street sweeping practices to offset the frequency of catch basin cleanings. These goals were
achieved by conducting a two-year study in the City of Ellensburg. The study area is a 1,065-feet
long section of SR 97 which includes four catch basins located on each side of the road that each
discharge runoff to a swale. During year one (2018), one side of the road (test site) was swept and
the catch…