TagDes Moines Creek(162)

A water resources consultant hired by the Airport Communities Coalition reviewed Sea-Tac Airport's August 2000 Stormwater Master Plan and found it seriously deficient in protecting local water quality. The review concludes that existing pollution controls at the airport are not working, that stormwater discharges regularly violate Washington State Water Quality Standards, and that the Plan's proposed measures fail to provide reasonable assurance that those standards will be met in the future. Key concerns include the diversion of polluted runoff away from local creeks, inadequate handling of metal roof runoff, and the lack of meaningful mass-balance accounting for long-lived pollutants.

A water resources consultant wrote to the Washington State Department of Ecology in September 2000, arguing that Seattle Public Utilities' Lake Youngs water supply is too warm to effectively cool Des Moines Creek during summer months. Temperature data showed that Lake Youngs outlet water exceeds 16°C from mid-June through mid-October — the exact period when cooler stream temperatures are needed — reaching as high as 20°C in summer 2000. The letter concludes that the Port of Seattle's proposed flow augmentation facility for Des Moines Creek cannot rely on this water source for temperature improvement, undermining the Port's claims about its water supply plan.

A water resources consultant submitted comments to the Washington State Department of Ecology in September 2000, raising serious concerns about the Port of Seattle's proposed Des Moines Creek Flow Augmentation Facility, which was intended to mitigate water quality impacts from SeaTac Airport's third runway expansion. The consultant argues the plan is vague and incomplete, lacking secured water sources, hydrologic analysis, and finalized design details. Key technical problems identified include unreliable water temperature from one proposed source, dependence on continuous technological systems, and a disputed well design that may violate state groundwater protection guidelines.

A biological assessments consultant, writing on behalf of the Airport Communities Coalition, critiques the Port of Seattle's revised plan to use City of Seattle drinking water to boost summer flows in Des Moines Creek near Sea-Tac Airport. The letter raises concerns that the plan inadequately addresses the toxicity of fluoride and residual chlorine in treated drinking water, which can harm fish and other aquatic life at very low levels. The consultant also warns that differences in temperature, pH, and dissolved oxygen between the makeup water and the creek could cause serious ecological damage if not corrected before augmentation begins.

This September 2000 preliminary design report, prepared by Kennedy/Jenks Consultants for the Port of Seattle, outlines a plan to augment water flow in Des Moines Creek near Seattle-Tacoma International Airport. The report covers facility configuration, process components such as backflow prevention, dechlorination, and aeration systems, as well as an evaluation of chemical dechlorination alternatives. The project was designed to improve creek water quality by treating and releasing water in a controlled manner.

A fisheries biologist assessed the Port of Seattle's plan to use City of Seattle drinking water to boost summer flows in Miller and Des Moines Creeks when levels drop below 1.0 cubic feet per second. The report concludes that chlorine and fluoride in drinking water are toxic to fish and other aquatic life at very low concentrations, and that mixing drinking water into these small streams would far exceed Washington State water quality standards even with dilution. The biologist recommended against the plan and suggested that treated well water from within the local watersheds might be a less harmful alternative.

A fisheries biologist, writing on behalf of the Airport Communities Coalition, assessed the Port of Seattle's plan to use City of Seattle drinking water to boost low summer flows in Miller and Des Moines Creeks near Sea-Tac Airport. The report concludes that the drinking water's chlorine and fluoride content would be highly toxic to fish and other aquatic life, far exceeding Washington State water quality standards even after dilution in the streams. The biologist recommends against the plan and suggests that well water from within the local watersheds may be a less harmful alternative.

Letter dated August 18, 2000 from Keith R. Smith, Water Resources Manager at Port Of Seattle (Seattle-Tacoma International Airport), to Jillian Hoyt of Seattle Public Utilities, regarding the Des Moines Creek Basin Plan Flow Augmentation Facility. The Port seeks to purchase water from SPU as an alternate supply for the proposed flow augmentation facility, which

In July 2000, the Port of Seattle submitted an Implementation Plan to the Washington Department of Ecology outlining a proposed Des Moines Creek Flow Augmentation Facility near Seattle-Tacoma International Airport. The plan describes using water from a Port-owned well — currently used for golf course irrigation — to boost creek streamflow to at least one cubic foot per second and lower water temperatures to 16°C during summer low-flow periods. An automated monitoring station downstream would control pump operations, with a backup option to draw from the Port's municipal water distribution system if well water became unavailable.

In July 2000, the Port of Seattle submitted an Implementation Plan to the Washington Department of Ecology outlining a proposed flow augmentation facility for Des Moines Creek, located near Seattle-Tacoma International Airport. The plan described using water from a Port-owned well to increase stream flow to one cubic foot per second and reduce water temperatures to 16 degrees Celsius during summer low-flow periods, with the goal of improving water quality and aquatic habitat. The facility would involve reconfigured well pumps, an 800-foot pipeline, a stilling basin, and an automated monitoring station to regulate flow and temperature in the creek.