SAN JOSE — San Jose Mayor Sam Liccardo, Santa Clara Mayor Jamie Matthews and other Silicon Valley leaders on Monday took big gulps of recycled water — filtered, cleaned and disinfected sewage — to show that it is safe and should be a growing part of Silicon Valley’s drinking water future.

“Delicious,” said Liccardo, as cameras clicked.

“Good stuff!” said Matthews, as video rolled.

Capitalizing on public interest in water supply issues during California’s historic drought, the pair appeared at a public water treatment plant in Alviso to unveil plans for an $800 million expansion of recycled water in Santa Clara County over the next 10 years.

Once derided as “toilet to tap,” recycled water has been used in San Jose and other cities in Santa Clara County since 1997, but only for irrigating golf courses, landscaping and other nondrinking uses, such as in industrial cooling.

Under the new proposal, San Jose and the Santa Clara Valley Water District are calling for expanding that use from 20,000 acre-feet a year now to about 55,000 acre-feet a year — or 20 percent of the county’s total water demand — by 2025. An acre-foot is about 325,851 gallons of water, or the amount that two Bay Area families of five use in a year.

And rather than using it only for landscaping, they hope to mix it with existing groundwater and serve it to back the public to drink. That’s not commonly done in California, although Orange County residents have been consuming purified wastewater for the past seven years.

To speed along the project, the two mayors said Monday, Sacramento political leaders should allow them to suspend the state’s landmark environmental law, the California Environmental Quality Act, which requires builders of large projects to draw up detailed studies of how new construction will affect smog, traffic, noise, wildlife and water quality. Doing an environmental impact report would add two years and $3 million to the project’s costs, they said.

“We need the state of California to get the regulations out of the way,” said Liccardo.

Exactly how, or whether, the law can be suspended for the project, however, was unclear Monday.

Liccardo and other leaders said they are hoping state Sen. Jim Beall, D-San Jose, can help them. But Beall has not introduced a bill, and the deadline for introducing new bills has already passed for this year.

A similar bill last year, AB 2417, by Assemblyman Adrin Nazarian, D-Van Nuys, that would have allowed recycled water pipelines less than 8 miles long to be built without the required environmental, or CEQA, review died in the state Senate over environmental opposition.

Environmental groups said Monday that even though they support recycled water, they will probably oppose efforts by Silicon Valley leaders to skirt a thorough review.

“While the project is likely to be very environmentally beneficial, the impacts need to be considered so construction can occur in ways that plan for the protection of air, water quality and human health,” said Miriam Gordon, state director of Clean Water Action, an Oakland-based group.

CEQA forces government to share details of projects before they are built, said Kathryn Phillips, director of Sierra Club California.

“The purpose of CEQA is to make sure the public has access to information about large projects that are going into their community so they can feel comfortable that any environmental impacts that might result from that can be mitigated,” she said. “It seems like an environmental impact review would be in order here.”

The project may be eligible for an exemption from CEQA under an executive order that Gov. Jerry Brown issued April 1. Among its 31 drought actions was one suspending CEQA for some water projects. But Brown’s exemption expires May 31, 2016, and because the expanded recycled water project is in its early stages, the board of the water district won’t vote on the final project for up to two years, said Jim Fiedler, chief operating officer of the district, so it might not qualify.

On the board’s agenda Tuesday is a measure to suspend competitive bidding for engineering studies on the project, in an amount up to $10 million. That could fast track the process, but also raised concerns.

“I’m very interested in expanding our purified water program. However, these single-source agreements are for a large sum of money, and I would like more information before I can authorize our CEO to move forward with them,” said water district board member Barbara Keegan.

The full $800 million to expand the plant and pipe its water to percolation ponds in Los Gatos, South San Jose and other locations could be funded with state bond money, federal funds and higher water rates, district officials said. The cost of the water would be about $1,100 to $1,500 an acre-foot, compared to about $400 now for increasingly limited supplies of water from the Sacramento-San Joaquin River Delta and $2,000 to $3,000 for desalination.

In July, San Jose and the water district opened the new $72 million Silicon Valley Advanced Water Purification Center in Alviso, where the mayors and local leaders, including Silicon Valley Leadership Group CEO Carl Guardino, guzzled recycled water from glass beakers on Monday. The facility takes sewage treated to secondary levels at San Jose’s wastewater treatment plant and further cleans it with microfilters, reverse osmosis and ultraviolet light. The final product is basically distilled water.

On Monday, water district officials said the water that political leaders drank for Monday’s photo op cannot yet be legally served to the public unless it has more state approval. But they said it meets all state health standards to drink.

“It’s excellent quality,” said Gary Kremen, chairman of the water district’s board, who called recycled water “drought proof.”

“We’ve got to consider all of the options on the table, and this is one of them.”

Paul Rogers covers resources and environmental issues. Contact him at 408-920-5045. Follow him at Twitter.com/PaulRogersSJMN.