Water Recycling Project about 95 percent complete

Watsonville’s Water Recycling Project, which is expected to provide more than 1 billion gallons of treated wastewater to local farmers every growing season, is 95 percent complete and should be ready for use in late November or December, city Wastewater Treatment Facilities Manager Kevin Silviera said Wednesday.

Currently, the city gives wastewater a secondary level of treatment, which makes water clean enough to pump into the ocean. The new facility will take water treated to a secondary level and give it treatment to a tertiary level — a level that is safe to use in agricultural fields, but isn’t safe to drink, Silviera said.

Aside from a few small jobs — such as some painting being done Wednesday — the main task remaining is to conduct testing on the facility to ensure that the water will, in fact, be safe for agricultural use, Silviera said. Test results will be sent to the state health department for evaluation.

“Tertiary in our business is the ultimate job satisfaction, because you can actually use the water instead of discharging it,” Silviera said.

The city currently treats 6,500,000 gallons of water per day. During the growing season, all of that water will be treated to a tertiary level. The city has agreed to provide the Pajaro Valley Water Management Agency, its partner on the project, with the 4,000 acre-feet of water — which amounts to 1.755 billion gallons — to distribute to farmers via the PVWMA’s Coastal Distribution System, Silviera said.

The PVWMA has been tasked with dealing with a longstanding and growing groundwater overdraft situation since it was founded in 1984. The Water Recycling Project is expected to solve about 20 percent of that problem. Planning for the project began about eight years ago, with construction having started about 15 months ago, Silviera said.

“We’re really excited about (the project),” said Mary Bannister, the PVWMA’s interim general manager. “It’s a safe, reliable supply of irrigation water that will really benefit the coastal growers.”

“The farming community depends on it,” Silviera said. “Every year we go through this drought, the demand just goes up.”

The combined cost of the Water Recycling Project and the Coastal Distribution System is $65 million, with about half of that paid through grants, Bannister said. PVWMA, struggling financially, owes the city $30 million for construction costs. The tertiary project has a $23 million price tag, while the Watsonville Water Resources Center — a new office building and laboratory that is slated to open in November 2009 — has a $10 million cost, Silviera said.

To reach a tertiary level of treatment, chemicals that coagulate effluent — unwanted waste particles — are added to secondary treated wastewater to allow it to be filtered in what is called a flocculation clarifier. Then the water will go through disk filtration, in which beams of ultraviolet light from 600 UV light tubes will be pass, killing cells of any organisms. The water will then be distributed to farmers.

Using tertiary treated water is nothing new, said Silviera, who added that farmers in areas affected by seawater intrusion as a result of the overdraft would be getting higher-quality water than what they are currently pumping out of the ground...

...Read full article at the Register-Pajaronian.