Grape-growing vs. Wastewater in Wine Country

Clark Mason, Press Democrat, 2009

When Jason Passalacqua, a Dry Creek Valley winery owner, heard about a plan to use highly treated wastewater to irrigate his vineyards, he thought it was a good idea.

“When I first heard about reuse, I thought great,” he said.

But he now considers the plan to use wastewater to grow grapes a “threat to the environment” of Dry Creek Valley and its world-class wines.

Dry Creek Valley Vineyard

Passalacqua belongs to a coalition of grape growers, winemakers, environmentalists and others opposed to the Sonoma County Water Agency’s plan for a $385 million project that could ship recycled water primarily from Santa Rosa’s regional sewage treatment plant to northern Sonoma County for agricultural use.

On Tuesday, he helped present the results of a study critical of the Water Agency’s environmental impact report for the project, which is up for adoption by the county Board of Supervisors on May 12.

Water Agency officials said the recycling project, which is envisioned as an alternative to drawing from the Russian River and underground water supplies, is likely years away from being built and only the environmental study is up for consideration. But critics said if the study is approved, it could sit on a shelf like a “ticking bomb.”

Passalacqua and other opponents of the plan fear treatment plants do not adequately filter out chemical compounds that could affect the quality of grapes and could negatively impact wells, creeks and fish.

But there are other grapegrowers who welcome the recycled wastewater and note that it has been used for years in agriculture.

“We’re working toward securing some of that water,” said Keith Horn, who heads the Coalition of Sustainable Agriculture, a group of more than a dozen grapegrowers and wineries that supports wastewater use.

“We understand everybody’s concern,” he said. But he said the recycled water is “swimming pool quality” and already used in some vineyards in Sonoma County and Napa. “We won’t do anything to compromise the integrity of our product, or property,” Horn said.

The North Sonoma County Agricultural Reuse Project would create 19 reservoirs and 112 miles of pipeline though the Dry Creek, Alexander and Russian River valleys.

Treated wastewater would be diverted from Santa Rosa’s pipeline that already delivers wastewater to the Geysers geothermal fields.

Besides effluent from Santa Rosa’s plant, which also serves Rohnert Park, Cotati and Sebastopol, it could also carry Windsor’s treated wastewater and some from Larkfield-Wikiup and the airport area.

“There’s a storm of wastewater headed our way,” said Ray Holley, a former Healdsburg newspaper editor who said the Water Agency’s plan amounts to a “wastewater superhighway” into the winegrowing region.

Water agency officials say treated wastewater has been safely used for years for agricultural purposes, is tightly regulated by state law and can be a reliable source of water in drought conditions.

Critics of the Water Agency’s plan said using recycled water may work in places like the Santa Rosa Plain, where soils are less permeable and wells are hundreds of feet below the surface.

But the sandy, gravelly soil in Dry Creek Valley that produces great wine is especially porous. Combined with a shallow water table, “it allows water to pass right through the soil and into the aquifer,” Passalacqua said.

However, Pam Jean, the Water Agency’s deputy chief engineer of operations, countered that recycled wastewater is being safely used as a water alternative around the world.

“If there is a recycled water project that ends up being implemented in the Dry Creek, Russian River or Alexander valleys, I have a hard time believing those areas are going to be any different than every other place it’s done,” she said Wednesday.

Russian River Enters the Pacific

She noted the project aims to reduce the longtime discharges from local wastewater treatment plants into the Russian River and its creeks, as well as reduce the use of ground and surface waters for agriculture.

The Clean Water Coalition of Northern Sonoma County, the 2,500-member alliance that Passalacqua is a part of, commissioned a study by professional hydrologists who said the effluent would infiltrate drinking water supplies and could exceed state standards for levels of copper and nickel.

The study found that reduced pumping of groundwater would alter the aquifer in detrimental ways. And it said the wastewater would quickly pollute stretches of waterways critical to the restoration of endangered salmon.

The study raised concerns that wastewater used for irrigation and frost protection would run off into creeks and deposit salts, nitrate, metals and other trace pollutants.

In recent years, there has been growing national concern over what remains in processed wastewater, including household products ranging from pharmaceuticals to shampoo.

Water agency critics also noted there has been evidence that estrogen traces in wastewater have caused male fish to sprout female organs.

But David W. Smith, a Santa Rosa water quality consultant, said Wednesday that those fish were exposed to much higher amounts of estrogen than what is found in Santa Rosa’s wastewater.

As far as the danger of wastewater infiltrating Dry Creek wells, he said, “recycled water properly applied in irrigation would not be detectable in wells.”

According to consultants hired for the environmental report on the Water Agency project, “our ability to measure extremely low levels of these trace constituents exceed our current understanding of the long term effects of such constituents.”

The environmental report notes that as more becomes known, discharge standards could be revised, providing protection to both the environment and public health.

“We would not be proposing a project that would be doing harm to the agricultural industry,” said Water Agency spokesman Brad Sherwood. “We would not move forward with a project that had negative implications to fisheries.”