Johnson Lake is a privately owned, shallow, 18 acre urban lake in an industrial area with PCB contaminated sediment and soil. Its very steep and heavily vegetated shoreline limits equipment access to the lake.
Conducted under the Oregon DEQ Voluntary Cleanup Program, remediation for this lake included covering the lake bottom with a thin layer cap to remediate PCB impacted sediment, excavating PCB contaminated upland soils, and construction of stormwater swale across the remediation area. [Click here for upland remediation information]
The original ROD remedy was to dredge PCB-contaminated sediment from the lake and place it in a confined disposal area over the upland impacted soils. When design investigations revealed that dredging alone would not be sufficient to meet cleanup goals, capping was then selected as the remedy. Dredging of the adjacent slough was required to compensate for floodplain capacity that would be lost when the lake was capped.
DOF provided the following services:
- Prepared Johnson Lake Sediment Remediation Conceptual Alternatives Comparison Report for dredging alternatives, including cost estimates
- Designed the sediment sampling plan, collected field samples, and prepared the sediment characterization report
- Tested engineering properties of in situ sediment for capping design
- Prepared capping permit applications (JARPA)
- Prepared plans and specifications
- Prepared project supporting plans including Construction Quality Assurance Plan (CQAP), Site Security Plan, Environmental Monitoring Plan, and Remediation O&M Plan
- Prepared construction bid documents, and assisted in contractor selection (evaluation of proposals, interviews, and ranking)
- Prepared RFI responses and reviewed submittals
- Managed construction meetings, conducted on-site coordination with contractor and owner, and provided field support inspections and observations documented with daily field reports and photos.