File photo by Sam Hodgson
Most of San Diego's sewage is treated at the Point Loma Wastewater Treatment Plant and then pumped into the Pacific Ocean.
Early next year, San Diego will finish a landmark pilot project meant to prove to health regulators that the city can safely recycle sewage by purifying it into drinking water. Then a major question awaits: What next?
A two-year city study, due to be presented to a City Council committee Wednesday, answers that question and other big unknowns, like how much it would cost to recycle sewage, where purification facilities should be built and how much sewage could be diverted from a major treatment plant in Point Loma.
The blueprint sets a goal for San Diego to recycle 100 million gallons of sewage daily in coming decades, saying its cost would be comparable to increasingly expensive — and volatile — imported water supplies. That would represent roughly 20 percent of the region’s supply.
The study, a draft of which was obtained by Voice of San Diego, leaves San Diego poised to make the largest paradigm shift in how it handles its wastewater since the city stopped dumping raw sewage in San Diego Bay and began treating it in the 1960s. The city’s sewage could become a valuable commodity, not the burdensome moniker it is today: Wastewater.
The report calls for a major, multi-billion-dollar expansion of San Diego’s water-reuse infrastructure, with new purification facilities in Point Loma, University City and the South Bay. If adopted, San Diego would join Orange County as a major pioneer in the American Southwest’s fledgling efforts to turn sewage into a drinking water source.
Today, San Diego imports billions of gallons of water annually from far-off sources, a practice that consumes massive amounts of energy and leaves the region vulnerable to supply interruptions. After traveling hundreds of miles to San Diego, the water is consumed once and flushed down the toilet before being treated and pumped into the Pacific Ocean.
Droughts, regulatory restrictions and the threat of climate change have exposed the frailty of that system and made imported water increasingly expensive. Against that backdrop, environmentalists and federal regulators have pressured San Diego to expand sewage reuse. San Diego’s major sewage treatment plant, which sits on the Point Loma bluffs near Cabrillo National Monument, is outdated, today operating under a temporary waiver of federal pollution rules.
The city has balked at an upgrade because of its $1.2 billion price tag. That cost could drop to $710 million if San Diego fully implements the sewage recycling strategy.
When San Diego was granted its most recent waiver, which expires in 2015, the U.S. Environmental Protection Agency warned the city to begin seriously weighing how it would reuse sewage. The study provides the most definitive answer yet, though whether it will be enough to satisfy the EPA remains unknown.
Nahal Mogharabi, an EPA spokeswoman, said the agency would soon meet with city officials, local water pollution regulators and environmental groups to discuss the study and the Point Loma sewage plant’s future.
“The agency believes that more efficient use of treated wastewater is critical to the future of both the San Diego area and much of the Pacific Southwest,” Mogharabi said. “EPA has seen a draft executive summary and looks forward to seeing more details about the conclusions reached by the study.”
Marco Gonzalez, the Encinitas environmental attorney who agreed not to sue the city in 2008 in exchange for the study, said its results are vital for those who want to see sewage recycled and diverted from polluting the Pacific.
“It’s pretty much unquestioned that this has to happen,” Gonzalez said. “The only questions are how it will happen, when it will happen and who will pay for it.”
Here are four key takeaways from the report:
• 1. Contrary to the yuck factor once associated with a water source derided as “toilet to tap,” purifying sewage would greatly improve San Diego water quality. Imported water today is salty, particularly supplies from the Colorado River. The pure water produced from reusing sewage would reduce salinity in taps across the region.
• 2. San Diego’s purple-pipe system isn’t a panacea. The system delivers sewage treated to be safe for irrigation but not drinking. While the report envisions a small expansion of San Diego’s purple-pipe system, it concludes that a major expansion would cost between $430 million and $550 million but only yield a small amount of water. Instead, it proposes new advanced purification facilities on Harbor Drive in Point Loma and at existing sewage plants in University City and the South Bay.
• 3. The study outlines what to do with San Diego’s sewage from now until 2035. But implementing that plan will take time, and the city has a 2015 deadline to get another federal pollution waiver for the Point Loma sewage plant. What happens in the meantime? Gonzalez said he expected a lawsuit would be necessary to create a court-ordered timeline for upgrading the city’s sewage infrastructure.
“We need to sit down and come to an agreement that’s meaningful to the environment and ratepayers,” Gonzalez said. “The only way to do that is a consent decree through a lawsuit. The timeframe for that is right now.”
• 4. An influential report that could dictate the future of water and sewer rates in cities across the San Diego region for decades hasn’t been released with any fanfare.
So far, it has simply been routed to a City Council subcommittee without any statement from Mayor Jerry Sanders, who until recently has opposed purifying sewage as a drinking water source. His office didn’t respond to an email seeking comment Monday.
Rob Davis is a senior reporter at Voice of San Diego. You can contact him directly at email@example.com or 619.325.0529.
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