Poison Pond 2 Disposal Site

Poison Pond 2 Disposal Site

Initial site development includes gravel road construction, guardrail replacement, and culvert installation. The ±27-acre disposal site would be accessed through construction of a one-way gravel access road located immediately north of SR 299 (see site plan, Appendix A of Initial Study). This would provide safe ingress and egress for construction vehicles, while also providing access to dump areas. Disposal activities would start at the southern portion of the project site and extend upslope as the site is filled. Upon full build-out, the anticipated fill slope would be 3:1. To maintain public safety, existing guardrail would be temporarily removed and reinstalled or replaced with new guardrail. To maintain stormwater flows, culverts would be installed under SR 299 and the one-way gravel access road. To maintain flows during active disposal activities, a ±48-inch-diameter by ±273-foot-long culvert would be installed at the base of the SR 299 fill slope, using the jack and bore method. Additionally, a ±60-inch-diameter standpipe with debris rack would be installed at the culvert inlet. The standpipe would be extended as needed to correspond to applicable fill levels (±100 feet tall at full build-out). The culvert outfall would receive an energy dissipater to minimize the potential for erosion. Further, smaller culverts would be installed along portions of the gravel access road to maintain area drainage. To maintain flows following build-out (i.e., 3:1 slope), another culvert would be installed under SR 299 near the road surface. A minor amount of pavement patching may be needed following culvert installation. Once the full build-out culvert is in operation, the standpipe/culvert would be abandoned in place and capped. Approximately 27 acres of soil would be disturbed during project implementation; maximum excavation depth would be approximately four feet. To minimize the potential for erosion, construction vehicle use would be limited to the proposed disposal site and SR 299 roadway. Further, on-site vegetation would be preserved until disposal activities warrant removal. Project construction would utilize one-way reversing traffic control as needed. Staging would occur within the Caltrans right-of-way and the proposed disposal site. The disposal site occurs on lands managed by the Bureau of Land Management (BLM). Caltrans would coordinate with BLM staff as needed to facilitate the proposed project. Project activities would be limited to Caltrans right-of-way and the project site.

Trinity

Northern California