Silicon Valley Clean Water (SVCW; formerly South Bayside System Authority) is in the planning stages of replacing an aging wastewater pipeline that runs from the San Carlos airport area to the treatment facility in southeastern Redwood Shores.
Join us at one of these meetings at SVCW's administrative offices 1400 Radio Road, Redwood Shores
- Wed. March 5th at 3 p.m. (with optional tour)
- Wed. March 5th at 7 p.m.
- Sat. March 8th at 10 a.m. (with optional tour)
- Wed. March 12th at 3 p.m. (with optional tour)
- Wed. March 12th at 7 p.m.
The meetings will share information about possible locations for the new pipeline and provide an opportunity for community members to share input. This is also an opportunity to take a tour of your wastewater treatment plant (daytime meetings only and wear closed-toed shoes; no sandals).
SVCW officials are studying possible locations for the new 63 inch diameter pipeline with the goal of identifying the route with the least disruption to Redwood Shores community and the most long term benefit to the community. We are seeking input on the possible locations. Whichever location is chosen, construction would begin in mid-to-late 2015.
The existing segment is a 40 year old, 54-inch concrete pipe (inside diameter) that carries more volume and operates at a higher pressure than originally designed. It also has a history of leakage and damage because of the unstable "young bay mud" ground in Redwood Shores. The pipeline will be replaced with a new, 63-inch line (56" inside diameter-- similar size to existing) made of high-density polyethylene (HDPE). This type of pipe is flexible to allow movement underground without leaking and is not subject to corrosion or deterioration from wastewater. The project does not add capacity or the ability to deal with more population, but is only to repair the leakage problems with the old pipe.
Four alignment options from San Carlos Airport through Redwood Shores are being studied: in the slough, in the lagoon, in the street, and in the levee. Initial information indicates the in-slough and in-lagoon options are impractical due to environmental and water quality impacts, difficulty in pipeline leak detection and repair, and conflict with boating and recreational activities, though in response to initial community input, the lagoon option is being further reviewed to determine if some of the impacts can be mitigated.
The in-street alignment along Redwood Shores Parkway would require extensive relocation of existing utilities, with one year of excavation and traffic control for utility relocation only. There would also be noise from sheet pile driving, and vibration combined with necessary trenching and dewatering. Installation of the new pipeline would require two additional years for construction and the associated traffic control (total of three years of construction). The streets and Parkway would be restored with new paving and landscaping.
The in-levee alignment would require the temporary closure of the levee trail and have short-term impacts to the area between resident's backyard fences and the levee. This route has very few existing utilities to move and would not require significant traffic control. Trail closures and impacts to each adjacent property would be minimized to the extent practical. The tight corridor and limited access requires that heavy construction occur in one or two locations at a time which limits the duration of impact to each adjacent property (overall period of construction of 1.5 years). Vinyl sheet lining would be used to strengthen the levee and would also help address rodents burrowing into the levee. Once complete, the levee would be restored with new trails and plantings, and SVCW will have an ongoing long-term interest in the levee's maintenance.
Once a preferred location has been determined based on community feedback and engineering studies, a California Environmental Quality Act (CEQA) document will be prepared to evaluate the potential impacts of the preferred pipeline location along with other alignment options. The public will have the opportunity to review and comment on the process as part of the CEQA procedure.
"As we begin studying the engineering options, we want the public's thoughts and ideas about the different pipeline location possibilities so the design process reflects the needs and concerns of our community," said SVCW Manager Dan Child.