Llano Trunk Pipeline Rehabilitation (California Endangered Species Act (CESA) Incidental Take Permit No. 2081-2024-049-03 (ITP))

Llano Trunk Pipeline Rehabilitation (California Endangered Species Act (CESA) Incidental Take Permit No. 2081-2024-049-03 (ITP))

This Project involves the rehabilitation of 8,170 linear feet of reinforced concrete pipe trunk sewer main. The existing underground 66-inch diameter sewer main pipeline is within a City of Santa Rosa-owned easement that spans the entire length of the Project. The trunk sewer main will be rehabilitated using trenchless cured-in-place pipelining technology, which consists of internally inspecting the pipeline via a closed-circuit television feed mounted on a “pig” within the pipeline, cleaning the interior of the pipe, and applying a sealant, fabric liner, and epoxy coat. The trenchless cured-in place pipeline technology will require excavation at thirteen sewer manholes ranging from 25 to 36 square feet with a depth of 4 to 6 feet. One manhole rehabilitation site is located within a seasonal wetland and will not require excavation. The Project will also include an above-ground temporary sewer bypass system for the duration of the Project. The temporary bypass pipeline consists of three 18-inch diameter pipes to maintain peak sewer function while the sewer main pipeline is being repaired. The temporary bypass pipeline will be connected to the sewer main via openings in one upstream and one downstream manhole. The temporary bypass pipeline will be removed after the completion of the sewer main repairs. The Project will be completed in one construction season. High Impact Areas include the primary egress and ingress routes, staging and stockpiling locations, liner launch points, non-excavation work areas requiring more extensive vehicle and equipment access, manhole rehabilitation and excavation areas, and the bypass suction and reinsertion locations. The High Impact Areas comprise 1.17 acres. Low Impact Areas include the portions of the Project where activity will be limited to foot traffic and no more than 30 one-way vehicle trips throughout the course of the Project. The primary work in these areas will include installation of the bypass pipe and liner termination points. Liner termination is done underground inside existing manholes. The bypass pipe will be propped up on wooden blocks every 50 feet within the Low Impact Areas. In addition, steel plates will be placed over drainages for access and plastic or wooden mats will be placed over wetland habitat within the Low Impact Areas to avoid soil rutting and crushing vegetation from vehicle traffic. The Low Impact Areas comprise 3.09 acres. The Project site also includes 0.37 acre of developed land and 0.01 acre where the bypass pipeline will free span a wetland and no impacts to the wetland will occur. The Project will result in temporary impacts to 1.17 acres of California tiger salamander habitat. The Project is expected to result in incidental take of California tiger salamander, which is designated as a threatened species under CESA. The ITP referenced above as issued by CDFW authorizes incidental take of species listed under CESA that may occur as a result of Project implementation.

Santa Rosa

Sonoma

San Francisco Bay Area

Sonoma