“Stoneway site” being purchased for park has history of contamination; carries use limitations

A picture of the Stoneway Site from the Tri-Park Master Plan

A recent press release from the City discussed the impending purchase of the Stoneway Site for extension of Cedar River Park, but did not mention the environmental remediation challenges that will come with it.

A graphic in a Department of Ecology letter shows locations of petroleum and formaldehyde contamination on the Stoneway site

I support the city purchasing this site as long as Renton gets it for a fair price and we get assistance from the Department of Ecology, State Fisheries, and others to help fully clean it up.

According to the Department of Ecology, there is still formaldehyde, petroleum residue and potentially other industrial waste on the site that is acceptably capped and monitored so long as none of the soil, concrete, and buildings are disturbed.  Any digging on the site requires Department of Ecology approval and likely a new environmental remediation plan.  The site is also subject to continuous monitoring for chemical movement, and carries liability for whoever owns it.

At Renton River Days there was a display asking residents what to do with this new parkland, but no mention of the serious contamination issues present that may limit the use.

Residents provided valuable input at River Days.  “Wants” include more pickle ball courts, turf fields, restrooms, climbing walls, more public art, disc golf course, indoor swimming pool, protecting the Cedar River, green spaces, trails, zipline, more sidewalks, shade, more trees, a spray park for kids, and many other great suggestions. Many of these would not be possible on the Stoneway site until significant additional cleanup work is completed.

Renton has a drinking water well in Cedar River Park, just a few thousand feet from the Stoneway site, so we should be grateful for the diligent Department of Ecology oversight of this property in recent decades.

Cedar River Park Well Station, on property adjacent to Stoneway site

These environmental concerns were why the City pressured Stoneway to relocate 25 years ago.  In the years since then, the owners of the site have removed some contaminated soil, installed monitoring wells, capped some areas, and made other remediation to minimize the risk of contaminant leaching into our water supply.

If Renton purchases the site, the future environmental stewardship will shift entirely to our city.  This might be the right decision, as long as we do not overpay for the contaminated property, and we recognize that more environmental cleanup work will need to be done before we can develop active recreational uses on the site.

An excerpt from a Department of Ecology letter which limits the use of the Stoneway Site