HANSVILLE — The state has released its proposal for removing toxins from a former Hansville landfill site, and it doesn’t involve backhoes or dump trucks. Instead, the Department of Ecology wants to let nature take charge. The agency proposes monitoring the site off Hansville Road and allowing toxin levels to decline on their own, a process it believes will take about 23 years and cost $1.8 million. Ecology will take public comment on the proposal through June 13 (see box).
Ecology developed a cleanup plan through an agreement with Kitsap County, which owns the site, and Kitsap County Sanitary Landfill, the former operator. Contaminants, including manganese, arsenic and cancer-causing vinyl chloride, are found in ground and surface water around the site.
Arsenic and vinyl chloride levels are below federal drinking water standards but exceed the state’s levels for cleanup, said John Keeling, who oversees the site for Ecology.
The one contaminant that exceeds federal drinking water standards is manganese, an element that infuses fresh water with an acrid flavor. The contaminants do exceed the more stringent standards for groundwater quality, which set guidelines for protecting delicate aquatic environments.
The landfill site is sandwiched between Hansville Road and the Port Gamble S’Klallam reservation, adjacent to the county’s Hansville Transfer Station. Kitsap County Sanitary Landfill, now a part of Waste Management of Washington, operated the site from the 1960s through the 1980s. It accepted solid waste, refuse from land clearing and construction demolitions, as well as septic pump outs.
The state, county and tribe monitor ground and surface water in a broad area west of the site and are confident the chemicals haven’t entered any drinking water wells. Still, the tribe estimates the contamination affects about 400 acres of its 1,300-acre reservation.
The property is within the tribe’s managed forest land. As a precaution, the tribe doesn’t allow berry harvests and other traditional activities on the property, Sullivan said.
“It’s something we’re going to have to deal with for a long time,” Tribal Chairman Jeromy Sullivan said. “We’re thankful it’s not effecting our drinking water and not effecting our human health.”
There were few viable alternatives for ridding the area of contamination, said Keli McKay-Means, project coordinator for the county. Because the toxins are present in very low levels, it would be very expensive to physically remove them. For example, the state could pump and treat groundwater from the site at a cost of $6.3 million and it would still take 18 years for toxin levels to drop to accepted standards.
In the end, the stakeholders decided the more invasive measures weren’t worth the expense or the disruption to the environment and community.
“We could spend a lot of money and not necessarily have a large result,” McKay-Means said.
If the cleanup proposal approved, water around the site would be sampled four times each year. Ecology will reevaluate its plan if contamination isn’t dropping as fast as expected or begins to rise, Keeling said.
Planning for the cleanup began soon after the landfill closed in 1989. The state added the property to its Hazardous Sites List. The garbage piles were capped with a membrane lining and soil.
Today, green grass blankets the manmade mounds. Birds flit through the trees nearby. County employees keep an eye out for burrows on the property and try to keep rodents from digging in. Sampling wells and methane venting machinery are about the only sign that some 600,000 tons of garbage lie beneath.
“It’s not a bad place to be if you have to be at a landfill,” McKay-Means said.
Cleanup Comments
Ecology is accepting public comments through June 13. Details are available online at: http://www.ecy.wa.gov/programs/tcp/sites/hansville/hansville_hp.htm.
The materials also may be viewed at the Little Boston Library, 31980 Little Boston Road NE, or Kingston Library, 11212 State Route 104. Comments can be sent to John Keeling, site manager, Department of Ecology, 3190 160th Ave. SE., Bellevue, WA 98008; email: jkee461@ecy.wa.gov.