Visitors to Dottie Harper Park in Burien may be seeing some signs around the park this spring that alarm them.

The Burien Parks Department and the state Department of Ecology (DOE) are posting “dirt alert’ signs for a few small areas of the park that contain moderate levels of arsenic. The arsenic comes from a smoke plume from the ASARCO copper smelter in Tacoma.

The smelter spewed the plume from 1890 to 1986 with prevailing winds spreading it north toward Vashon-Maury Island, Des Moines, Normandy Park, Burien, SeaTac and Tukwila. Parks, childcare centers and schools have been tested over the past 10 years.

DOE is contracting with a firm to dig up about a foot of soil in the grassy area in the southeast part of the park’s eastern edge. Also an area just north of the playground near the slide will be dug up. New soil and grass will be placed in the areas.

Amy Hargrove, DOE’s soil safety program coordinator, said other Highline parks that DOE would like to perform some future cleanup work include Sunset Playfields and McMicken Heights in SeaTac and Parkside in Des Moines.

Hargrove said the agency suggests cleanup in areas that average 20 milligrams of arsenic per kilogram of soil or any spot that is over 40 milligrams.

Lafreniere said the two grassy-area samples tested 39 and 58.5 while the area north of the playground came in at 34.9.

The signs going into the parks will urge visitors to continue to enjoy the park but suggest several “healthy actions” to reduce contact with the contaminated soil:

Wash hands and toys with soap and water after playing in the dirt.
Wash hands before eating or putting anything in your mouth
When you get home, take your shoes off or use a doormat.
Wipe off your pet’s dirty paws, too.

The smelter shut down in 1986 but the contaminated soil will continue to be a health risk for years, according to DOE officials.

The soil contamination is also worse in undisturbed forested areas. Landscaped land was less affected. On beaches, the arsenic didn’t bind to the sand and tended to wash away, according to DOE staffers.

DOE’s soil safety program began in 2005 to clean up play areas at schools, licensed childcare facilities, parks, camps and multi-family housing units. Arsenic is most dangerous to children. Children under six are at greatest risk because they tend to put things into their mouths.

The agency has sampled over 1,000 sites and performed cleanup at more than 100 locations,

The state of Washington recently received $94 million in a lawsuit over the plume so has entered the next phase of the cleanup.

Arsenic, because it stays in the ground, is more of a concern than lead, Hannah Aoyagi, DOE public involvement coordinator, said at a recent open house.

She noted arsenic may contribute to heart disease, diabetes and certain cancers.

People are exposed to arsenic by eating or breathing in the contaminated dirt. Gardening and construction work causes added exposure. Pets and humans also track the dirt into homes, Aoyagi noted.

Aoyagi said DOE is encouraging people to take healthy actions around the home, such as hand washing, removal of shoes, cleaning toys, damp dusting and vacuuming and washing fruits and vegetables. Cleaning pets’ feet when they come inside has also been suggested, she noted.

Aoyagi reported the agency offers brochures and advice for sampling soil, tips on how to make yards safer, furnishes nailbrushes and magnets as well as providing classroom curriculums.

Some of the gardening tips are basics, such as grow vegetables in raised beds and cover the soil with bark or wood chips.

Hargrove said the agency is encouraging voluntary cleanup efforts. She noted this could be done during construction. The DOE can provide guidance and is working with local permit offices. Help is also available on how to sample soil. Cost to sample soil is $20-$50, Hargrove reported.

There are several cleanup options, though none are inexpensive, Hargrove said. The contaminated dirt can be dug up and removed, capped with clean soil or concrete or mixed with clean soil.

About $64 million of the $94 million lawsuit settlement is slated for a yard sampling and cleanup program. However, for now, it is restricted to Vashon/Maury islands and the Tacoma area. By 2014, Aoyagi said, DOE hopes to begin education programs for new homebuyers and real estate agents as well as encouraging soil sampling as part of the real estate sales.

Those wishing more information may contact Aoyagi at360-407-6790 or haoy461@ecy.wa.gov.