St. Helena’s wastewater treatment plant could need $14.1 million worth of upgrades.
The San Francisco Bay Regional Water Quality Control Board issued a new permit in 2016 requiring the plant to meet more stringent treatment standards. The water board also issued a cease-and-desist order with a timeline for the city to evaluate and implement upgrades.
Based on a feasibility study by the consultant GHD, city staff recommended installing a trickling filter system ($8.14 million) with an infiltration pond ($543,900), tertiary filtration ($1.5 million), electrical upgrades ($1.1 million) and a disinfection system ($849,100).
In addition to those Phase 1 improvements, staff is recommending reclamation field improvements, facilities automation, a new well, and Phase 2 upgrades that would add another $2 million to the price tag, for a total of $14.1 million.
The council directed staff Tuesday to negotiate a new contract with GHD to design the upgrades.
Cost estimates are still preliminary, and it’s still unclear exactly how much of the cost could be covered by the new wastewater rates.
The city is already applying for a loan from the U.S. Department of Agriculture. As designs take shape and cost estimates are refined, staff will return to the council with recommendations on possible funding strategies such as grants, loans, cash and impact fees.