TagModel Toxics Control Act(35)

This Washington State Department of Ecology fact sheet explains how the Model Toxics Control Act (Initiative 97, 1989) governs the cleanup of hazardous waste sites in Washington, outlining who is liable, how sites are identified, and the options available for conducting cleanups. Potentially liable parties — including past and present owners, operators, and those who transported or disposed of hazardous substances — may clean up sites independently or work cooperatively with Ecology through formal agreements such as consent decrees. Note: this document concerns hazardous waste site cleanup regulation and does not contain information related to Sea-Tac Airport noise policy.

This document summarizes correspondence and records related to environmental cleanup efforts at Seattle-Tacoma International Airport, covering the period from 1997 to 2001. It details how Governor Locke conditioned his 1997 certification for the airport's third runway expansion on the Port of Seattle completing a study of decades-worth of hazardous waste contamination in the soil and groundwater at the site. The records also trace the lengthy negotiations between the Port and the Washington State Department of Ecology to establish an Agreed Order under the Model Toxics Control Act, which was ultimately signed in May 1999.

WAC 173-340-740 from the Model Toxics Control Act (MTCA) Cleanup Regulation, published February 12, 2001, establishing unrestricted land use soil cleanup standards. Covers Method A, Method B (standard and modified), and petroleum mixture cleanup levels including Equations 740-1 through 740-3 for noncarcinogens and carcinogens. Specifies default exposure parameters: soil ingestion rate 200 mg/day, average body

This Washington State regulation (WAC 173-340-747) establishes methods for determining safe soil contamination levels that protect groundwater quality at cleanup sites. It outlines several scientific approaches, including three-phase and four-phase partitioning models, leaching tests, and empirical demonstrations, to calculate the maximum allowable concentration of hazardous substances in soil before they risk contaminating groundwater. The regulation requires that soil concentrations not cause groundwater cleanup level exceedances and not result in the buildup of nonaqueous phase liquids in or on groundwater.

Exhibit AR017360, Part IX Tables from MTCA Cleanup Regulation WAC 173-340-900, dated February 12, 2001. Contains Table 720-1, Method A Cleanup Levels for Ground Water, listing hazardous substances including arsenic, benzene, benzo(a)pyrene, cadmium, chromium, DDT, 1,2-dichloroethane (EDC), ethylbenzene, ethylene dibromide (EDB), lead, lindane, methylene chloride, mercury, MTBE, naphthalenes, PCB mixtures, radium 226, tetrachloroethylene, toluene, trichloroethylene,

A January 2001 letter and accompanying meeting notes document communications between the Port of Seattle and the Washington Department of Ecology regarding a groundwater contamination study at Seattle-Tacoma International Airport, conducted under the Model Toxics Control Act (MTCA) Agreed Order 97TC-N112. The records outline the scope of the study, which focuses on hydrogeologic investigation and a review of the Fuel Operations Area, and clarify that any necessary cleanup would be handled separately after the study's completion. Both parties discussed concerns about scope expansion and the process for addressing contaminated sites identified through the study.

A scientist retained by the Airport Communities Coalition wrote to the EPA in December 2000, raising serious concerns about the Port of Seattle accepting contaminated fill materials for the proposed Third Runway project at Seattle-Tacoma International Airport. The letter argues that the Port improperly used Washington State's Model Toxics Control Act (MTCA) cleanup standards as fill acceptance criteria, when those standards were designed to clean up existing contaminated sites, not to permit introducing pollution onto previously clean land. The scientist also criticizes the Port's soil testing methods as statistically inadequate to detect the true extent of contamination, warning that chemicals in the fill could leach into groundwater, wetlands, and surface water including Miller Creek.

Email chain dated September 11, 2000 among Kevin Fitzpatrick, Peter Kmet, Chung K. Yee, Joan Marchioro, and Tom Luster of Washington State Department of Ecology (Water Quality Program, NWRO) regarding clean fill criteria language for the 401 Water Quality Certification on the Sea-Tac Third Runway project. Document marked ‘Deliberative Document Currently Exempt From Public Disclosure.’

Internal email dated September 11, 2000 from Peter Kmet to Chung K. Yee (cc: Kevin Fitzpatrick) discussing new Method A soil cleanup levels under MTCA (Model Toxics Control Act) and their use as a basis for defining clean fill. Kmet addresses specific chemicals including arsenic (recommends 7 PPM background value from USGS statewide study instead

A March 2000 Parametrix memorandum reports the results of pesticide and herbicide soil testing at the Vacca Farm site, part of the Port of Seattle's Third Runway Project. Of 59 compounds tested, only 12 were detected, primarily organochlorine pesticides, with Dieldrin slightly exceeding cleanup levels in shallow soil samples at two locations in the proposed floodplain area. The memo recommends removing the upper six inches of soil from the floodplain area for offsite disposal, while concluding that the proposed Miller Creek relocation corridor does not pose unacceptable risks to human health.