Santa Rosa explores high-strength wastewater option

[caption id="attachment_88477" align="alignnone" width="438"] City of Santa Rosa's Laguna de Santa Rosa wastewater treatment plant (image courtesy of the city of Santa Rosa)[/caption]

SANTA ROSA -- The Santa Rosa City Council on March 4 is expected to allocate new funding to study allowing trucks to deliver high-strength wastewater directly to the Laguna Wastewater Treatment Plant, a potential boon for regional wineries, breweries and others that currently haul such waste to a treatment facility in Oakland.

Part of a broader $1.2 million allocation of funding from the California Public Utilities Commission, the approval would be an early but tangible step toward a long-discussed proposal to further accommodate the accelerating growth of the region's beverage and food producers.

While determining the specific amount of North Bay waste currently trucked to the large Oakland Treatment Plant is difficult, wine industry waste -- most from the North Coast -- accounts for between 4 percent and 5 percent of total trucked waste at the plant annually, according to a spokesperson for the East Bay Municipal Utility District.

Rerouting that waste to the plant in Santa Rosa, along with brewery waste and other sources like dairies, could generate new revenue for the facility, reduce transportation expenses and increase efficiency, according to industry advocates and planners.

"Who wants to drive to East Bay MUD when you can go three miles?" said David Guhin, Santa Rosa's director of utilities.

While other wastewater facilities in the North Bay have explored the concept in the past, the existing capacity of the Laguna plant and the allocation of funding by the city council could mean that necessary upgrades go forward as early as this year, Mr. Guhin said.

The decision would hinge on a number of factors, including identification of up to $1 million in funding to construct a receiving station at the Laguna plant, according to Mr. Guhin and council materials. The council is expected to allocate $150,000 toward the proposal through a consent calendar vote on March 4, along with other measures related to the Laguna plant.

That cost could be significantly mitigated in the long term by the fact that the Laguna plant captures methane produced from the breakdown of organic waste for energy production. Redirecting waste destined for the East Bay would mean more methane production, reducing an electricity bill that currently averages $4 million per year, the utility director said.

"The nice thing is that it would start to pay off immediately," said Mr. Guhin, adding that the nature of that waste could also help the facility's overall breakdown of organic material to run more efficiently. The Laguna plant is one of the largest in the region, able to handle high-strength waste delivered through the regular sewer and around 21 million gallons of waste per day.

Notable for a high density of materials ranging from grape skins, oils and septic waste, high-strength wastewater can entail large fees if directly disposed of in a regular sewer. Such disposal is typically charged based on the multiplication of wastewater volume and strength, and even a relatively small amount of waste can entail large costs if of sufficient intensity.

Typical homes measure between 170 and 175 in "biochemical oxygen demand," a common measurement of the strength of organic material in wastewater. Peak waste from wineries can reach 5,000 BOD or even more, with breweries typically ranging from 600 to 5,000 BOD.

In the case of Petaluma's Lagunitas Brewing Company, the necessity to transport high-strength waste from the brewing process has meant six-to-seven shipments of wastewater per day to the East Bay at an annual cost around $1.5 million, said founder Tony Magee.

"It's horrendously expensive," said Mr. Magee, describing plans for a $6 million pretreatment facility that will soon handle the company's waste on-site.

He described the recent growth of specialty food and beverage manufacturers in the North Bay as entailing a "process of discovery" for municipalities as they encounter the corresponding impact on their infrastructure. Lagunitas is within the service area of Petaluma's Ellis Creek treatment plant, a facility that has faced a surge in high-strength organic waste as those industries increase production.

"When it's on a boutique scale, that's one thing," he said, noting how specialty food and beverage is core to the region's identity. "What happens when these companies grow up? Do they have to move to the Central Valley?"

Pre-treatment systems are not a catch-all: in the case of wineries, the intermittent flow of waste can impact the ongoing health of microorganism colonies that allow many pre-treatment systems to operate efficiently.

The situation has lead to a bottom-line calculation for some producers that it is cheaper to pay a hauling company to transport that waste for treatment in Oakland, where East Bay MUD charges three cents per gallon for treatment of liquid organic waste.

"It's not cost-efficient. It's not environmentally friendly. Yet the economics of it are such that it is the best option for many of them," said Rex Stults, government relations director for the Napa Valley Vintners, which represents nearly 500 wineries.

The Napa Sanitation District itself studied the proposal for direct delivery of hauled winery waste as recently as 2009, but so far has not pursued such infrastructure. The district has recently been meeting with the Napa Valley Vintners to discuss wastewater issues in general, with high-strength waste treatment options emerging as an area of interest, said Tim Healy, general manager.

"We're now looking at the ability to take that waste here locally," said Mr. Healy, who noted early talk of other proposals that include shared pretreatment facilities.

The extent to which Santa Rosa will plan a potential receiving station for serving the broader region has yet to be determined, along with pricing and other specifics that would ultimately go before the city council, Mr. Guhin said.

Yet the new functionality could to support other efforts to attract wineries, breweries and other businesses to Santa Rosa itself, said Santa Rosa Mayor Scott Bartley.

"We're looking at a significant use of funds to do this," he said. "It makes it easier for those companies to come in."

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