Vallejo Flood & Wastewater District Begins Major Mare Island Water and Sewer Improvements

By on August 20, 2018

The city of Vallejo’s Flood & Wastewater District (VF&WD) has begun a major water and sewer project to improve the reliability of service on Mare Island. The Mare Island Sewer and Water Main Replacement Project, estimated to cost nearly $16 million is anticipated for completion in early February 2019. Both the city of Vallejo and VF&WD will contribute $7 million each. A grant from the U.S. Environmental Protection Agency will contribute $1.2 million.

The project entails new pipelines to be installed 75 feet underneath the Mare Island Causeway and a second one further down the Strait. Using a boring technique, the new pipelines will be pulled through new borings 95-feet north of the Mare Island Strait and 75-feet below the river bed. The project will increase water capacity and better support economic development on Mare Island.

The project also calls for including conduits for VallejoNet fiber optics and a recycled water main for future potential projects. All environmental reviews were completed and were adopted by the City Council and water district’s trustees in April of last year.

The existing 18-inch force main was built in 1974, is in poor condition and is difficult to access for monitoring and maintenance. However, it is a critical component of the Vallejo Flood & Wastewater District’s sanitary sewer collection and discharge system on Mare Island.

The replacement sewer force main will be tunneled deep beneath the Mare Island Strait using horizontal directional drilling. It will continue via an open trench through River Park and then cross the Mare Island Causeway to Harbor Way, where it will connect to an existing sewer line under Mare Island Way.

Additionally, the city’s drinking water mains serving Mare Island are dated; 20-inch line, located farther down strait will be taken out of service. A new tunnel with dual 18-inch drinking water mains and fiber optic conduits will be separate from the tunnel containing the new sewer and recycled water pipes. The tunnels for the water and sewer pipes will be about 15-feet apart.

The project is anticipated to entail some noise, traffic and park impacts but the city and the water district have work with contractors to minimize disruption. Between September and early February of 2019, work hours will vary from eight hours a day, five days a week to 12 hours a day, 6 days a week, with few exceptions. As the new piping is pulled through the borings work will occur around the clock for two days per bore and bright lights and generator noise will be apparent.

Although River Park will remain open, its parking lot and park staging area may be impacted. Some of the park paths may have detours during construction. Lane closures on Mare Island Way, Harbor Way, and the Mare Island Causeway may occur later in the project but no full street closures are anticipated.

Questions regarding the project and additional information as the project progresses should be directed to Ed O’Brien at 707-654-9622. Questions about park access should be addressed to the Greater Vallejo Recreation District at 707-648-4600.