HomeMy WebLinkAboutC_Letter_of_Understanding_Geologic_Risk_180309_v1L41
King County
Department of Natural Resources and Parks
Wastewater Treatment Division
King Street Center, KSC-NR-0501
201 S Jackson Street
Seattle, WA 98104-3855
206-477-5371
January 18, 2018
Mr. Clark H. Close, Project Manager
City of Renton
Department of Community & Economic Development Planning Division
1055 South Grady Way
Renton, WA 98057
Subject: Letter of Understanding of Geologic Risk
South Plant Biogas and Heat Systems Improvements
Dear Mr. Close,
The City of Renton identified that the proposed King County Wastewater Treatment Division
(WTD) facility is located within a critical area consisting of a moderate coal mine hazard. As a
result, King County WTD commissioned Brown and Caldwell and their subconsultant, Shannon
and Wilson, to perform a Coal Mine Hazard Evaluation of the area around the proposed facility.
Shannon and Wilson evaluated the available documentation for the coal mine, recently completed
boring logs and test pits, and determined there was no surface or subsurface evidence to suggest
past mining activities in the area of the proposed facility that would pose a geologic risk to the
project.
Even though no evidence was present, King County understands and accepts the risks associated
with developing in the area if unstable conditions are discovered during construction.
Should you have any questions, or require additional information, please contact us at your
convenience.
Sincerely,
Susan Hildreth, P.E.
Project Manager
Enclosure: Geotechnical Report Addendum
CREATING RESOURCES FROM WASTEWATER