Big improvements are in store for San Mateo’s sewage treatment facilities, including possibly turning wastewater into drinking water.
In the near term, the changes will result in cleaner wastewater flowing to the San Francisco Bay, and enable much of the city’s car and truck fleet to be powered by energy reclaimed from waste.
The city’s short-term goals also include turning wastewater into nonpotable “gray” water that will be used to irrigate landscaped medians and parks.
Long-term, however, city officials may even begin converting wastewater into safe, potable drinking water depending on the outcome of California’s drought.
San Mateo’s wastewater treatment plant is located east of U.S. Highway 101, and serves San Mateo and Foster City, as well as portions of Hillsborough, Belmont, the Crystal Springs Sanitation District and unincorporated San Mateo County.
The roughly $23 million project includes upgrading the facility’s computer control network, installing a new crane for improved safety and operations, replacing motor control centers, and replacing various filters, pumps, pipes, gates and valves.
The plant’s ability to extract solid waste and convert it to compressed natural gas (CNG) is also getting a big boost with the addition of new refinery equipment and a CNG gas station for fueling city vehicles.
Some of the renovation and upgrade work is well under way, but the city held a groundbreaking ceremony Monday.
Councilwoman Maureen Freschet noted San Mateo had just 500 residents when it was incorporated in 1894, but the town still relies on some of the same wastewater infrastructure installed during that era, despite its population having grown to more than 102,000 residents.
Mayor Joe Goethals elicited laughs from the gathering of city officials and contractors when he joked that some of the equipment being replaced was older than City Manager Larry Patterson, who is 65 and has worked for the city since 2000.
Councilwoman Diane Papan also provoked chuckles when she quipped, “When I ran for office, my big slogan was, ‘I’m gonna make sewers sexy!’”
But when it comes to some decidedly un-sexy topics, Clean Water Program Manager Cathi Zammit said the city would need strong cooperation from residents.
Baby wipes and similar products for adults can create huge problems in sewer systems, and must be separated from wastewater before solid waste can be converted to CNG, Zammit said.
“Baby wipes are not biodegradable like they say they are,” the program manager noted.
Zammit explained baby wipes often clog the sewer lateral lines connecting homes to city sewers, forcing homeowners to pay thousands of dollars to repair pipes on their properties.
Zammit said the acronym “FOG,” for fats, oils and grease, can help residents remember what substances should not be poured down drains.
“Please don’t pour cooking oil or fat from steak down your drain,” Zammit said.
San Mateo Facilities and Fleet Services Manager David Fink said the plant’s increased ability to manufacture CNG from waste would play a key role in the city’s plan to rotate 75 percent of its nonemergency fleet to natural gas-powered vehicles over the next two years.
That means about 220 staff cars, along with Public Works and Parks and Recreation trucks, will have their carbon footprints reduced by running on CNG. But when it comes to emergency services, Fink noted police and fire officials tend to prefer to wait and see whether new vehicle technologies prove themselves in less critical applications.
The city, for instance, plans to have Police Chief Susan Manheimer trade in her unmarked Ford Taurus-based Police Interceptor for a CNG-powered Chevrolet Impala so she can determine whether its performance and reliability are adequate for police work.