GIBBS RESERVOIR RECLAMATION PLAN

In 2010, Lowham Walsh developed a landmark reclamation plan according to newly adopted WDEQ guidelines for reservoir reclamation. This plan was the first to be submitted and approved by WDEQ, and is currently used as the regulatory standard. The approved plan was a comprehensive reclamation plan for two reservoirs, Gibbs #2 and Gibbs #6 in adjacent drainages on land owned by a private landowner. Our staff performed all necessary surveying of the existing embankments and basins, and performed depth-integrated water-quality sampling. These data were used to design treatments intended to improve the quality of the impounded water to WDEQ standards for discharge. Once water treatment was completed, our staff designed a breach plan for each reservoir site. Upon successful permitting with the WDEQ, Lowham Walsh engineers and technicians provided construction oversight for the breach process, prescribed erosion control best management practices (BMPs), mapped the full extent of inundation from the release downstream of the site, and corresponded with the State Engineer’s Office on the breach plan and cancellation of the reservoir permits.

Once the reservoirs had sufficient time to dry, our staff conducted soil sampling of each basin, embankment, and collected control samples at the WDEQ-required intervals. Samples were analyzed for constituents designated in the WDEQ reservoir reclamation guidance. Using soil sampling analytical data our staff developed reclamation plans in accordance with the reservoir reclamation guidance that included a soil mitigation plan. The mitigation plan emphasized the use of the embankment material to fill the basin without the need for costly remediation measures and soil amendments. The plan included designated fill and topsoil material and placement, site re-contouring, a landowner approved seed mixture and seeding plan, straw mulch application and anchoring, and installation of erosion and sediment control BMPs. Further, the Lowham Walsh reclamation planning staff provided several versions of plans for the Operator to compare basin excavation schemes, met in the field with WDEQ staff to discuss the merits of each plan, worked closely to obtain landowner approval of the overall reclamation activities, and assisted the Operator’s management with the contracting and bidding process.

Lowham Walsh obtained WDEQ approval of the reclamation plan in fall 2010 and reclamation activities commenced almost immediately. The staff provided construction grade staking and oversight to the construction contractor performing reclamation earthwork, and reported progress to the Operator and WDEQ. Both reservoir reclamations were completed in December 2010. Due to weather related issues, seeding and erosion control BMP placement were delayed until April 2011. Lowham Walsh staff further assisted the Operator with seeding specifications, straw mulch application and anchoring, and erosion control BMP placement. Our staff is currently conducting semi-annual reclamation performance monitoring and reporting monitoring results to the WDEQ and the Operator until the performance bond for the site is released.