What You Have to Disclose (and What You Don't)
The Asarco smokestack has been gone for more than thirty years. Even so, it still puts a small asterisk on some North Tacoma home sales. It doesn't show up as a landmark anymore. It shows up as a question on a disclosure form.
From 1890 to 1986, the copper smelter on the border of North Tacoma and Ruston did what smelters do. Along the way, it sent arsenic and lead drifting across roughly 1,000 square miles of the Puget Sound region. The state calls that footprint the Tacoma Smelter Plume. If you live in the North End, Ruston, or University Place, there's a good chance you're in it.
Do I Have to Disclose It?
Washington's seller disclosure form, Form 17, asks whether you know of any soil contamination on the property. The key word is know.
Living inside the plume doesn't automatically mean your yard is contaminated. Many yards were remediated. Levels vary a lot, even from one block to the next, and sampling is the only way to find out. If you've never tested and have no reason to suspect a problem, your answer reflects that. If you have tested, or the state tested your yard at some point, then you know, and the results need to be disclosed.
One wrinkle sellers don't expect: if you answer "yes" to anything in the Environment section of Form 17, the buyer can't waive the form. It's coming along for the ride. That said, buyers rarely waive Form 17!
We're Realtors, not attorneys. If you are unclear how your situation will affect your disclosure requirement, consulting with an attorney is the right move.
Your Yard May Already Have a File
The Department of Ecology keeps a public map, called the Dirt Alert map. Anyone can type in an address and see whether the soil was sampled and whether the property qualified for cleanup.
"Anyone" includes buyers, their agents, and their inspectors.
Should I Test Before Selling?
The state offers free soil sampling, and it encourages owners to sign up even if they're planning to sell. The state’s Yard Program pays to remove and replace soil on eligible properties. That said, most sellers do not test prior to listing, or ever. And it rarely comes up in the transaction these days.
Once you have results, you have something to disclose. This is not a terrible situation. If the results were that you qualified for soil replacement, you can take that step or disclose that the buyer can. If the readings were not high enough to qualify, disclosing that may be enough to give your buyer piece of mind.
The Takeaway
The Asarco Plume is Generally Not a Deal Breaker For Most Transactions
Look up your address on the Dirt Alert map, decide whether testing makes sense for you, and fill out Form 17 based on what you actually know. North Tacoma buyers have been working around this for decades.
Helpful links
- Dirt Alert map (look up your address)
- Tacoma-Pierce County Health Department, Dirt Alert program: tpchd.org, (253) 649-1853
- Ecology's guide for buyers and sellers, then search "real estate in the Tacoma smelter plume"




