Project: Investigation & Clean Closure
Location: Seattle, Washington
The former Penberthy Electromelt plant was the site of hazardous waste
vitrification, a process that left much of the facility, drainage, and
creek contaminated with metals, dioxins, and furans. This property required
cleanup to residential levels before it could be transferred to the new
Because of project complexities and communications between the client
and the Washington Department of Ecology, several other consultants had
been unable to make progress in this investigation and cleanup. One had
even been observed discharging water from a Baker tank into the creek.
We negotiated with Ecology to implement a cost-effective investigation
that targeted analytes and grouped Solid Waste Management Units. This
multi-staged program was designed to remove contamination in soil, buildings,
concrete, drainage ditches, and creeks. By obtaining competitive bids
from laboratories across the country, we slashed the costs for dioxin
analyses in half. Among our most innovative solutions was an on-site evaporator
for dioxin-contaminated water; this saved over $500,000 in disposal fees
during cleanup. Likewise, we saved the client an additional $500,000 in
soil removal fees through our discovery of artificially high thallium
levels caused by interferences from high-iron soils. Other work for this
project included developing a position paper on “derived-from”
hazardous waste designation to attain “contained in” determinations,
saving the client even more in more disposal fees. We also identifed migration
pathways for contaminants that originated from incinerator and wastewater
sources, surface transport, rainwater infiltration, and leaching.
Our hands-on project management and clear communication with Ecology,
the client, and the cleanup team was instrumental in reaching clean closure.
We addressed unforeseen conditions efficiently, saving over $1 million
in cleanup costs.