Black Lake Grocery groundwater monitoring

We monitor groundwater for legacy petroleum hydrocarbons at the Black Lake Grocery site near Olympia. We provide groundwater data so that our Toxics Cleanup Program can evaluate the effectiveness of a treatment wall in remediating petroleum-contaminated groundwater before it enters Black Lake.


Remediating contaminated groundwater

Study area beside Black Lake in Thurston County

Black Lake Grocery is an active gas station and convenience store located on the northwest shore of Black Lake in Thurston County. Groundwater samples are collected every 18 months from select wells for total petroleum hydrocarbons as gasoline (TPH-G), and benzene, toluene, ethylbenzene, and xylene (BTEX). The groundwater data are used to evaluate the effectiveness of the installed treatment wall to remediate the petroleum-contaminated groundwater before it reaches Black Lake.

Database entries

Reports and project plan