TagHighline Water District(10)

Highline Water District reached a settlement with the Port of Seattle after PFAS chemicals, likely originating from Seattle-Tacoma International Airport operations, were found to have contaminated the District's Tyee Well, forcing the District to suspend well operations in June 2022. The contamination required the District to purchase more expensive replacement water from Seattle Public Utilities, and new EPA regulations finalized in 2024 further prohibited resuming well use without installing costly treatment facilities. The two parties negotiated a mutual release of claims to resolve the District's operational and financial losses resulting from the contamination.

This map from Highline Water District's Water System Plan shows the district's Regional Water Service Area (RWSA) and surrounding city boundaries in the communities near Sea-Tac Airport, including Burien, Normandy Park, Des Moines, SeaTac, Tukwila, Kent, Federal Way, and unincorporated King County. The document depicts roads, water bodies such as Angle Lake, Lake Fenwick, and Star Lake, and parcel boundaries across the service area along the eastern shore of Puget Sound. While primarily a water infrastructure planning document, it provides detailed geographic context for the municipalities and neighborhoods in the Sea-Tac Airport vicinity.

This document is a water system facilities and pressure zones map for the Highline Water District, covering communities including SeaTac, Des Moines, Burien, Normandy Park, and Federal Way in the greater Seattle area. It shows the locations of water mains, pump stations, storage facilities, wells, water treatment plants, and pressure-reducing valves (PRVs) across more than a dozen distinct pressure zones. The map is part of the district's Water System Plan and was produced by engineering firm Carollo.

This map from Highline Water District's Water System Plan shows the district's service area and surrounding water utilities in the communities south of Seattle, including areas near Sea-Tac Airport. It identifies neighboring providers such as the Port of Seattle, KCWD 20, KCWD 49, KCWD 54, KCWD 125, Tukwila, Kent, and Lakehaven Utility District, along with key landmarks like Angle Lake, Star Lake, and Lake Fenwick. The map delineates the Regional Water Service Area (RWSA) boundary and current service areas relative to major roads and Interstate 5.

The Highline Water District's 2022 Consumer Confidence Report details the sources, treatment, and quality testing of drinking water served to customers in the Kent and SeaTac, Washington area. Approximately 75% of the district's water comes from Seattle Public Utilities' Cedar River Watershed, with the remaining 25% drawn from local groundwater wells, all of which are treated and tested for over 200 contaminants before reaching customers. The report confirms that Highline Water District's water meets all state and federal safety standards and is significantly below EPA maximum contaminant levels.

The Highline Water District 2020 Annual Report details the operations and infrastructure of a public water utility serving the Kent, Washington area, which supplied approximately 2.3 billion gallons of water to nearly 19,000 active meters that year. The report covers water production and quality, preventative maintenance, and capital improvement projects, including the $9.4 million Mansion Hill Reservoir Relocation. It also describes how COVID-19 impacted district operations, leading to modified work schedules, suspended late fees, and delays in several planned infrastructure projects.

In June 2000, the Port of Seattle submitted a formal application to the Washington Department of Ecology to add a new use to an existing groundwater right for a well located on Port property near Seattle-Tacoma International Airport. The well, originally drilled in the late 1940s and previously used to irrigate the Tyee Valley Golf Course, was proposed to also provide flow augmentation and temperature control for Des Moines Creek as part of a jointly funded basin restoration plan. The application addressed the well's ownership history, its continuous use for golf course irrigation since the mid-1960s, and the Port's agreement with Highline Water District confirming the Port's title to the associated water right (Certificate No. 2369).

In November 1999, Highline Water District and the Port of Seattle reached a settlement agreement resolving competing claims over two water rights near Seattle-Tacoma International Airport. Under the deal, the Port retained rights to Well #1 for uses including Des Moines Creek flow augmentation tied to the proposed third runway project, while the District secured rights to a replacement for Well #2 to continue providing drinking water to its 58,000 customers. The District emphasized that the agreement was strictly about protecting its water rights and service area, and that it took no official position on the controversial third runway expansion.

Appendix E contains public comments submitted in response to the Final Environmental Impact Statement (FEIS) for the Seattle-Tacoma International Airport Master Plan Update. Commenters include the Highline Water District, the Washington State Department of Ecology, the U.S. Public Health Service, and the Washington State Department of Natural Resources, raising concerns about groundwater contamination, the handling of aircraft de-icing glycols, storm water runoff, and surface mining permit requirements for borrow sites on Port of Seattle property. The agencies generally called for stronger mitigation measures and clearer answers to environmental questions before approving the proposed airport expansion.