Discharge of Recycled Water on Fields a Smart Use of Water

July  16, 2015

Discharge of Recycled Water on Fields a Smart Use of Water

Napa Sanitation District Using Treated Wastewater on Alfalfa Crops

 

Napa, California – Motorists traveling on Highway 12 near Highway 29 and North Kelly Road this summer may see something on nearby land that’s unusual during this historic drought: large quantities of water being sprayed onto green fields. The landowner, Napa Sanitation District, would like the public to know that this use of non-potable treated recycled water is a necessary part of its wastewater treatment and disposal process, and also brings environmental benefits.

The water being used is not drinking water – it is tertiary-treated, disinfected recycled water from the District’s wastewater treatment plant. That plant receives around 9,800 acre feet of sewage annually for treatment, and it currently converts about 20% of that into recycled water suitable for irrigation or industrial use (one acre-foot is approximately 326,000 gallons). The District sells a great deal of recycled water to several golf courses, a cemetery, a large city park, Napa Valley College, surrounding business parks, construction firms for dust control, and some vineyards. But for now, there is still a substantial excess of that recycled water which must be disposed of.

During winter and spring, treated water can be discharged into the Napa River – but regulations prohibit that discharge from May through October. The District produces recycled water during this time for its customers, and the surplus is used to irrigate alfalfa or other crops in its fields. The District contracts with a farmer to plant and harvest the crops, which are typically used as feed for animals. 

It’s understandable that when people see those green fields being watered they wonder about such use during the drought,” said Jill Techel, Chair of the Napa Sanitation District Board of Directors. “I can assure them that it is recycled water that we are using on the fields.

The District is working to expand and improve its treatment facilities to nearly double the amount of recycled water it can produce by the end of the 2015, which is great water-saving news - especially during this historic drought. And, the District is building 14 miles of recycled water distribution pipelines in partnership with Napa County and the Los Carneros Water District. Upon completion, the customer base for recycled water will be large enough to greatly reduce the discharge of water on District property. In 2016, most of the treatment plant’s recycled water will be delivered to customers, thus saving millions upon millions of additional gallons of drinking water for the community’s use. 

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. Covering 20 square miles, NSD has been serving the community since November 1945. For further information about the District, please see www.NapaSan.com.

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