Dangerous Waste Permits

Contained-In Determinations*

If you have soil, groundwater, or other environmental media contaminated with a listed hazardous waste, you must manage the entire volume of media as if it were hazardous waste until it no longer contains the hazardous waste or is delisted.

Under the contained-in policy, the Department of Ecology (Ecology) may determine that your contaminated media no longer contains a listed hazardous waste when the hazardous constituents in your media are below risk-based levels.

Contaminated Soil

Soils excavated during cleanup actions are
sometimes contaminated with listed wastes.

In Washington, the risk-based levels are usually cleanup levels calculated using unrestricted use exposure assumptions from the Model Toxics Control Act (MTCA) Cleanup Regulation. These cleanup levels are calculated according to MTCA Method B using default exposure scenarios and risk assumptions. MTCA Method A cleanup levels for unrestricted land uses may also be appropriate. These risk-based levels are compared to Universal Treatment Standards (UTS) for all regulated hazardous constituents in your contaminated media.

Ecology may require contingent management of your contaminated media. This includes covering truckloads of soil, spraying excavated soils with water for dust control, or other requirements necessary for protecting human health and the environment. Ecology examines potential risks and pathways of exposure to evaluate whether contingent management is adequate. 

Ecology uses cleanup standards calculated using unrestricted use exposure assumptions. In limited cases, when you include provisions for more stringent contingent management in your request, Ecology may approve your request with risk-based levels calculated using MTCA industrial standards. Ecology will consider the mobility and toxicity of contaminants in your media, as well as the potential impacts of your contaminated media on landfill operations.

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*The terms 'contained in' and 'contained out' are used interchangeably.