Advice on soil sampling and cleanup for developers

Arsenic and lead in soil puts people at risk, especially children. We provide free advice for developers and property owners on how to sample soil for arsenic and lead contamination and to complete cleanup.

Development is a great time to take care of contaminated soil and reduce risks for future residents. Arsenic and lead from the Tacoma smelter plume are usually in the top six inches of soil. Digging and grading, a part of development, can also be part of the cleanup.

We recently updated our Tacoma Smelter Plume Model Remedies Guidance. We updated some information and links to additional resources, and created a new chapter on how to sample in natural areas.


Contact us for advice

Contact our Technical Assistant for advice on:

  • Questions about the Tacoma Smelter Plume Model Remedies Guidance.
  • How to sample soil for contamination.
  • How to develop cleanup plans.

If you are a developer planning a project within the Tacoma smelter plume, we recommend the following:

  • Search our interactive map to find out if your property is in the plume.
  • Read the Tacoma Smelter Plume Model Remedies Guidance to learn more about how to test soil for arsenic and lead contamination and complete cleanup, if needed.
  • If the sampling results show contamination on your property, consider joining the Voluntary Cleanup Program (VCP). The VCP provides technical assistance and a written opinion. Getting written approvals via the VCP is free for projects with Tacoma smelter plume contamination.
  • Protect your workers and the environment. State law requires employers to protect workers who could be harmed by contaminated soils. Construction sites must also prevent dust or stormwater runoff from leaving the site. Our fact sheets have more information:

For more information, contact Diana Ison at Diana.Ison@ecy.wa.gov or 360-999-9593.

How do I know if the soil is contaminated?

Ecology has Tacoma Smelter Plume Model Remedies Guidance for sampling your soils. You do not need special equipment or expertise. Samples cost around $30–$40 each to analyze for arsenic and lead. The number of samples depends on the size of the area, past uses, and how you plan to develop it.

How do I clean up my land?

Ecology strongly recommends digging up soils and sending them to a landfill. This cleanup method best protects human health and is permanent. In some cases, you can cap over soils with cleaner soils or pavement. Where arsenic and lead levels are fairly low, you can mix in cleaner soils to dilute the contamination.

See Ecology’s Tacoma Smelter Plume Model Remedies Guidance for more details on how to do cleanups. For more information about cleanups, please contact Diana.Ison@ecy.wa.gov at 360-999-9593.

I need Ecology approval of my cleanup

If a local government permit office or lender requires Ecology’s written approval of your cleanup, you must enter the Voluntary Cleanup Program (VCP). Also, a future buyer might want to see Ecology’s written approval of your cleanup. The VCP provides technical assistance and a written opinion. Getting written approvals via the VCP is free for projects with Tacoma smelter plume contamination only.

Protecting workers and the environment

State law requires employers to protect their workers, who could be harmed by contaminated soils. Construction sites must also prevent dust or stormwater runoff from leaving the site. Our fact sheets have more information: