SEATTLE -- Environmental investigators received their first look at the groundwater moving through Seattle's heavily contaminated Gasworks Park.
State Department of Ecology hydrologists have been waiting for the first round of results from last September's study measuring the flow and direction of the groundwater under the iconic park.
The report shows a very slow seep moving in a southeasterly diagonal direction across the park. The concern is the groundwater is picking up highly toxic materials trapped in the offshore sediment of the park and releasing it into Lake Union.
"At the bottom of the water, the sediment is very contaminated," said Department of Ecology Spokesman Larry Altose. "At some places up to 16,000 parts per million polycyclic aromatic hydrocarbons (PAHs)."
PAHs are suspected cancer-causing chemicals left over the 60 years of coal, oil and gas burning at the gasworks plant to produce fuel for a growing Seattle.
Much of the parks toxic legacy is buried under a thick layer of clean dirt, but it occasionally surfaces inside park in the form of oozing tar, and the sediments around the park got direct exposure to toxins that fell from loading docks.
The study shows the groundwater is moving through the sediment at a rate of about a gallon or two per day.
The City of Seattle and Puget Sound Energy will review the findings as part of their obligation to clean up sediments that threaten the health of the lake, animals and possibly the people who use it.