Element 1 - Interceptor Sewer Pipeline Bypass and Abandonment:

Most of the sewer pipelines currently located in high-risk areas under the lake will be shut down, sealed and abandoned in place. New gravity sewer lines and three new sewage lift stations will need to be constructed. Wastewater from certain existing residences will need to be rerouted using small pump systems (called grinder pumps) that send the flow through new or existing sewer pipes in safer areas.

                    Oak Shores, California – The westside interceptor sewer pipeline shown in blue with the exposed segments shown in red (ref: 2015 Risk Analysis Study)

                 Oak Shores, California – The eastside interceptor sewer pipeline shown in blue with the exposed segments shown in red (ref: 2015 Risk Analysis Study)

                                                        Oak Shores, California – Exposed segments of the interceptor sewer pipeline during low lake level

Element 2 - Interceptor Sewer Pipeline Rehabilitation

Some sections of the sewer pipeline that are in lower-risk areas will stay in use but will be repaired using a cured-in-place pipe (CIPP) lining. This strong lining will reinforce the inside of the remaining pipes without digging them up. This is a more affordable option than replacing the pipe in its entirety.

Element 3 - Lift Station No. 3 Coating

Lift Station No. 3 is an important facility that pumps all of the community’s wastewater to the treatment plant. Although it’s located outside the lake’s high-water area, the pump chamber is about 60 feet underground. Over time, the inside of the station has corroded due to moisture and gases. This part of the project will include repair of certain damaged elements of the lift station and application of a special protective coating to the inside of the station to prevent further damage and extend its lifespan.

                                                                     Oak Shores, California – Corrosion on infrastructure components within Lift Station No. 3