Georgetown is so metal

Soil study shows high levels of lead and other contaminants on some residential properties

Soil samples taken from Duwamish Valley residences found high levels of contaminants. (Photo by Steve Lannen)

By Steve Lannen

A couple months ago, as the daffodils began to flower and the tulips poked through the soil, I daydreamed about this summer’s garden. Herbs, tomatoes, dahlias, maybe cucumbers?

Then, an email raised my eyebrows: My soil has a high level of lead.

Yikes! When ingested or absorbed through the skin at high enough levels, lead can cause cancer.

Contaminated soil is a reality for many living in the Duwamish Valley and one of the many challenges of living in a place surrounded by industry. I’ve been here long enough to know our area’s dirty history. We live near an EPA Superfund site. Two airports and major roads foul the air. The state ecology department is constantly cleaning up the messes of long-gone manufacturers. We have worse health outcomes than people in wealthier neighborhoods.

But I always wondered about my property. How bad was it?

Last summer, researchers with the Duwamish Valley Research Coordination Network sampled my soil and that of 16 other properties in Georgetown and South Park. They also took samples from other sites like the Georgetown Steam Plant, outfalls at the Duwamish River and Jack Block Park. They tested for heavy metals, like lead, and for hydrocarbons, including gasoline and motor oil.

Results showed most of the residences tested exceeded the natural level for arsenic found in soil in the Puget Sound. Half the sites exceeded 100 mg/kg of lead. No amount of lead is good, but above the threshold of 100 mg/kg is a concern research study coordinator Simon Richard said. (Great, guess my yard is an overachiever at 210 mg/kg?)

Richard assured me Georgetown residents don’t have to wear a HAZMAT suit while mowing the lawn or quit gardening. We do need to be smart and strategic. Here are a few tips:

-          Leafy greens and plants with edible stalks and stems (chard, kale, lettuce, etc.) seem to take up the most contaminants. Plant them in containers or raised beds with organic soil.

-          Fruiting plants (tomatoes, squash, etc.) don’t take up as much of the contaminants. Those can still grow in the ground.

-          Use plastic gloves when handling soil or wash garden gloves often.

-          Wear a mask if it is dry and windy to prevent breathing dust.

-          Air pollution is also a risk, so wash everything before eating.

If anything, Richard made me feel more empowered in my yard. I also feel confident about my decision to grow anything I eat in containers.

Partially funded with an EPA grant, the study’s results will be compared with other studies and maps to hopefully determine sources of the contaminants, Richard said. Sites near the river tend to show higher contaminant levels than residential sites suggesting one hypothesis, he said.

To learn more about the DVRCN’s work, go to https://sites.google.com/uw.edu/dvrcn/