Presentation Abstract
Water-quality problems in urban and suburban streams are commonly blamed on stormwater pollution -- but actual stormflow pollutant data are much more limited. We analyzed 18 years (1993-2010) of stormflow metals concentrations from 33 stream stations across King County. We tested for long-term trends, compared stormflow and baseflow concentrations, and assessed aquatic and human-health toxicity. Five metals had long-term trends, all beneficial. Lead, nickel, and zinc concentrations have decreased over time. Calcium and magnesium concentrations have increased, which can reduce the adverse effects of toxic metals. In comparison to baseflow, 13 metals had discernably higher concentrations in stormflow (during 2001-2003 when metals were measured in baseflow). We assessed toxicity using state and federal regulatory water quality standards (WQSs), plus non-regulatory salmonid-specific screening values (SSVs). For aquatic toxicity, several samples were above WQSs for copper or lead, and 84% of streams had samples above the mercury chronic WQS. Ratios to WQSs were
Session Title
Stormwater Characterization and Management Using a Watershed Approach
Conference Track
SSE3: Fate, Transport, and Toxicity of Chemicals
Conference Name
Salish Sea Ecosystem Conference (2018 : Seattle, Wash.)
Document Type
Event
SSEC Identifier
SSE3-375
Start Date
6-4-2018 10:30 AM
End Date
6-4-2018 10:45 AM
Type of Presentation
Oral
Genre/Form
conference proceedings; presentations (communicative events)
Contributing Repository
Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.
Subjects – Topical (LCSH)
Runoff--Washington (State)--King County; Runoff--Environmental aspects--Washington (State)--King County; Water--Pollution--Washington (State)--King County
Geographic Coverage
King County (Wash.)
Rights
This resource is displayed for educational purposes only and may be subject to U.S. and international copyright laws. For more information about rights or obtaining copies of this resource, please contact University Archives, Heritage Resources, Western Libraries, Western Washington University, Bellingham, WA 98225-9103, USA (360-650-7534; heritage.resources@wwu.edu) and refer to the collection name and identifier. Any materials cited must be attributed to the Salish Sea Ecosystem Conference Records, University Archives, Heritage Resources, Western Libraries, Western Washington University.
Type
Text
Language
English
Format
application/pdf
Included in
Fresh Water Studies Commons, Marine Biology Commons, Natural Resources and Conservation Commons, Terrestrial and Aquatic Ecology Commons
Is stormwater harming our streams? Long-term monitoring of metals in stream stormflow
Water-quality problems in urban and suburban streams are commonly blamed on stormwater pollution -- but actual stormflow pollutant data are much more limited. We analyzed 18 years (1993-2010) of stormflow metals concentrations from 33 stream stations across King County. We tested for long-term trends, compared stormflow and baseflow concentrations, and assessed aquatic and human-health toxicity. Five metals had long-term trends, all beneficial. Lead, nickel, and zinc concentrations have decreased over time. Calcium and magnesium concentrations have increased, which can reduce the adverse effects of toxic metals. In comparison to baseflow, 13 metals had discernably higher concentrations in stormflow (during 2001-2003 when metals were measured in baseflow). We assessed toxicity using state and federal regulatory water quality standards (WQSs), plus non-regulatory salmonid-specific screening values (SSVs). For aquatic toxicity, several samples were above WQSs for copper or lead, and 84% of streams had samples above the mercury chronic WQS. Ratios to WQSs were
