Skip to main content


Buy Article:

$17.50 plus tax (Refund Policy)

Or sign up for a free trial


During a twelve month period in 1998-99, the Port of Seattle characterized the whole effluent toxicity (WET) of stormwater samples from four outfalls at Seattle-Tacoma International Airport (STIA.) This testing was conducted in accordance with USEPA and Washington State guidelines and the Port's individual NPDES stormwater permit for the airport. The WET tests used two aquatic organisms, a water flea (Daphnia pulex.) and the fathead minnow (Pimephales promelas.)

All eight test results for two of the outfalls met the Washington State Department of Ecology performance standards for survival for each organism. These two outfalls drain 79% (200 ha, 492 ac) of the airfield runways and taxiways. Nine of ten test results for a third outfall, that drains 60 hectares (149 acres) of mostly access roadways and the terminal and cargo building rooftops, also met the performance standards. In contrast, seven of nine WET results for a fourth outfall that drains 6 hectares (14 acres) of rooftops and roadways were below the performance standards and led to a subsequent source tracing investigation.

Supplemental sampling and analysis, including metals chelation with EDTA indicated that zinc was the most likely source of toxicity in samples from this fourth outfall. Further investigations revealed that about 0.8 hectare (2 acres) of zinc-galvanized metal rooftop on two air cargo buildings was the principal source of the zinc, where typically 50% or more was in the dissolved form. Synthetic runoff samples obtained by spraying domestic water on the metal rooftops also exhibited toxicity and considerable zinc, while the raw domestic water did not. The Port is investigating opportunities to remedy this apparent source of toxicity in the runoff that originated from a tenant-owned facility. As a result of this work, the Port is considering policy development that would address rooftop materials.

Document Type: Research Article


Publication date: 2000-01-01

More about this publication?
  • Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed.

    A subscription to the Proceedings of the Water Environment Federation includes access to most papers presented at the annual WEF Technical Exhibition and Conference (WEFTEC) and other conferences held since 2000. Subscription access begins 12 months after the event and is valid for 12 months from month of purchase. A subscription to the Proceedings of the Water Environment Federation is included in Water Environment Federation (WEF) membership.

    WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access. Access begins 12 months after the conference or event
  • Subscribe to this Title
  • Membership Information
  • About WEF Proceedings
  • WEFTEC Conference Information
  • Learn about the many other WEF member benefits and join today
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more