Work to start on MST recycled water pipeline

July  02, 2014

Work on the five-mile pipeline that will ultimately deliver high-quality recycled irrigation water to the Milliken-Sarco-Tulocay (MST) area east of Napa will begin at the end of July, Napa County and Napa Sanitation District officials announced today. The Sanitation District Board awarded the $7.6 million pipeline construction contract to Sanco Pipelines, from the South Bay, and a $2.4 million contract to build a booster pump station to GSE Construction of Livermore.

When completed in 2015, the pipeline is expected to initially deliver up to 700 acre-feet (228 million gallons) of recycled water during the high-demand summer months, although the pipeline will be large enough to carry up to 2,000 acre-feet in the future, as more recycled water becomes available from NSD and more property owners opt to use recycled water on their landscaping, vineyards and other crops.

Construction will primarily be in County roadways.

"This is great news for the MST area," said District 5 Napa County Supervisor Keith Caldwell. "The groundwater aquifer there is overdrafted by about 2,000 acre-feet per year and the day this project is put into service, it will be able to deliver enough water to offset up to 35 percent of that overdraft. That percentage will only grow as more people opt in to use the water."

"The Napa Sanitation District is proud to partner with Napa County to construct this pipeline and expand recycled water use," Jill Techel, Napa mayor and chair of the Napa Sanitation District Board, said. "Especially in this time of drought, it is important to recover and reuse the valuable water resources we have available to us. This is a great example of what can be accomplished with residents and local governments work together to solve a common problem."

The new section of recycled water pipeline will run approximately five miles, from the northwest corner of Skyline Park (on Imola Avenue) to the end of Third Avenue, at its intersection with Hagen Road, adjacent to the Napa Valley Country Club, one of its primary customers. A booster pump station will be built on Napa State Hospital grounds, allowing the water pressure to remain high enough to reach the higher elevation locations towards the end of the pipeline.

A combination of federal grants and a very low interest (1 percent) State Revolving Fund loan of $10 million from the Regional Water Quality Control Board will pay the total project cost of about $13.3 million. Project staff has also applied for additional state grants earmarked for drought relief. The RWQCB loan will be repaid over 20 years by the users of the recycled water, who will pay a special Community Facilities District (CFD) tax on their property tax bill.

"Our grant and loan efforts have been greatly helped by our membership in the North Bay Water Reuse Authority," Caldwell said. "The regional approach to using recycled water gave weight to our applications." The NBWRA includes includes several water and sewer districts from Napa, Sonoma and Marin counties, dedicated to increasing state and federal support of regional water recycling projects.

Although recycled water can only be used for irrigation and landscaping purposes, there are a large number of potential customers in the MST area, including many vineyard properties. Approximately 350 acre-feet of water has already been subscribed, on an annual basis, with significant capacity available for additional customers. One acre-foot will irrigate approximately three acres of vineyard for a year.

"The Napa Sanitation District is investing $15 million to expand our treatment process to produce the recycled water that will flow to the MST area once we build the pipeline," said Tim Healy, general manager at Napa Sanitation District. "This investment will allow us to deliver recycled water that has been treated to the highest standards."  Interested property owners can contact Deputy Director of Public Works Phillip Miller at (707) 259-8600 or As new members join the CFD, each individual member’s Special Tax amount is reduced accordingly. Participation is strictly voluntary.

The Board of Supervisors and staff of Napa County are dedicated to preserving and sustaining Napa County for present and future generations as a community with generous open space, a thriving agricultural industry and a quality human and natural environment. Visit us on the Web at

Napa Sanitation District (NSD) provides wastewater collection, treatment, and disposal services to the residents and businesses in the City of Napa, Silverado Country Club, the Napa County Airport and several adjacent unincorporated areas. NSD also provides recycled water service to portions of southern Napa County. For further information about the District, please see

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