July 22, 2014

TID leaders see how Turlock recycles water

Leaders of the Turlock Irrigation District toured the city of Turlock’s sewage treatment plant Tuesday. They are interested in using the highly treated output on farms.

Leaders of the Turlock Irrigation District, which has provided Tuolumne River water to the area since 1900, got a look Tuesday at another possible source.

They toured the city of Turlock’s sewage treatment plant, which turns out water fit for use on crops.

The visitors said they had a general interest in city operations, but the tour also provided an up-close look at a recycled water source that has been under debate in recent months. The city in January was about to sell some of the supply to the Del Puerto Water District, which serves farmers on the West Side, but TID stepped in with its own claim.

“In the drought, I think any source of water is critical,” board Chairman Ron Macedo said near the visit’s end. He also noted the long-term prospect of reduced water from the Tuolumne because of fish protections, and increased regulation of the district’s groundwater sources.

The city made the wastewater fit for farming with a $34 million project completed in 2005 at the plant, off South Walnut Road in the southeast part of town. It added “tertiary” treatment to primary and secondary phases that have been used for decades. The process involves screening, filtering, digestion by bacteria, chlorination and several other steps.

“The whole treatment plant mimics nature,” said Dan Madden, who retired as director of Turlock Municipal Services but still helps out at the plant. “We just speed it up.”

Madden led the tour of the 164-acre operation, which does not stink as much as a visitor might expect. “What smell?” he said when the topic came up.

The plant gets about 10 million gallons of sewage a day from Turlock, Denair and Keyes. An additional 1 million gallons comes partially treated in a pipeline from Ceres. Industrial wastewater, mainly from Turlock’s dairy and poultry processors, makes up nearly half the load.

A small part of Turlock’s recycled water irrigates Pedretti Park and cools a TID power plant fueled by natural gas. The rest flows into the San Joaquin River. Solids are mixed with the city’s green waste to make a fertilizer available to gardeners.

The water recycling would be much greater under the plans for supplying Del Puerto, which also would involve treated wastewater from Modesto.

Del Puerto serves about 45,000 acres along Interstate 5 between Vernalis and Santa Nella. It is among the many districts getting zero water this year from the federal Central Valley Project. Even in recent wetter years, the supply has been curtailed to protect fish.

Del Puerto could meet about two-thirds of its permanent annual demand with the 59,000 acre-feet of recycled water that eventually could be available. The district is seeking an initial supply of up to 13,000 acre-feet a year under a five-year deal with Turlock.

Anthea Hansen, general manager at Del Puerto, said last week that the water would help sustain agriculture on the West Side and would have economic ripple effects in a wider part of Stanislaus County.

Officials with TID say the recycled water could make up for some of the river water it might supply to a proposed treatment plant that would provide drinking water to Turlock, Ceres and south Modesto. The new supply could be used in western portions of the district, which has about 150,000 irrigated acres in southern Stanislaus and northern Merced counties.

“TID is interested in tertiary water to mitigate any potential future loss in supplying the city with drinking water,” board member Rob Santos said during the tour. “It’s the right thing to do to keep the water in our system.”

The drinking water plant would allow the cities to reduce their reliance on wells. Other parts of Modesto have done this for about 20 years thanks to a plant owned by the Modesto Irrigation District.

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