Upgrade considered for Paso Robles sewer plant

Correction: An earlier version of this story incorrectly said that an $84,000 contract will upgrade Paso Robles’ wastewater treatment plant. The contract is being considered for a third-party review of the upgrade’s design to ensure it's ready for construction bids.

The Paso Robles City Council will consider an $84,000 contract tonight to review its upgrade plans for its wastewater treatment plant, which discharges into the Salinas River.

The contract is being considered for a third-party review of the upgrade’s design to ensure it's ready for construction contractors to bid on. The actual cost of the upgrade is currently estimated at $51 million in 2012 dollars, according to city staff.

The upgrade of the 52-acre site near Highway 101 and the river on the northeast side of town is top-of-mind for city officials as a local agency is threatening steep fees on the city if its discharge quality doesn’t improve.

The city owns, maintains and operates the treatment facility, which was built in 1954 and treats 4.9 million gallons per day, according to city documents.

It was upgraded and expanded in 1972, 1987 and 2002, staff said, but “uses the same technology as when it was put into operation 55 years ago.”

Some examples of its outdated equipment include existing inflow screens and other filters that are “beyond their useful life” and aging equipment that allows excessive solids to pass into the chlorine disinfection process, which affects quality.

Since 2004, the plant has been under a new permit with restrictive regulations on the discharge of copper, selenium, ammonia and other organic and chemical compounds. The existing technology cannot consistently meet discharge requirements, city documents say.

That has spurred the Regional Water Quality Control Board to threaten fees on the city if the discharge quality doesn’t improve. That means up to $10,000 in daily penalties, said Matt Thompson, Paso Robles’ wastewater manager.

The upgrade is designed to bring the plant into compliance with discharge regulations, according to city staff, and incorporate energy efficiency in its building features and equipment.

Construction of the upgrade is set to begin around March 2011 and be complete by September 2013. The city included the upgrade in its recent capital improvement program and in May approved the project and a report detailing the environmental impacts it could have on the area.

Another plus city staff tout is that the new quality discharge “will likely be suitable for irrigation and other uses and thus become an integral element in the city’s future water supply,” Thompson said. Paso Robles has stepped up its mandatory water-conservation measures over the past two years.