San Diego is not well endowed with many freshwater sources to support its growing population, so some water experts are perplexed the city’s ignoring a self-replenishing local groundwater source that, though small in size, is safe from the threat of natural disasters and reliably recharged by the San Diego River.
The city’s not only overlooking the Mission Valley aquifer water as a resource – it’s planning to build a multibillion-dollar water purification project called Pure Water right over it.
“Whether it’s worth devoting our resources to developing this aquifer, my decision has been, probably not,” said John Stufflebean, executive lead for Pure Water San Diego, a $5 billion wastewater recycling project expected to provide a third of San Diego’s water supply when it’s complete in 2035.
He said size matters: “Is it better to develop Pure Water where you get 83 million gallons a day or look at another resource that’s 1 million gallons a day?”
But state leaders are pressing water managers not to rule out any local sources, no matter how small, as the state faces worsening natural disasters. Under an executive order last year, Gov. Gavin Newsom urged cities to diversify their supplies, including managing groundwater basins that could provide “a crucial buffer against drought and climate change.”
Part of the city’s justification for leaving the Mission Valley aquifer untouched is that it’s still contaminated from one of the largest gas spills in California history.
More than 20 years ago, petroleum seeped from pipes at the Mission Valley Tank Farm, a site just north of the former Chargers Stadium, which served as San Diego County’s gas hub since the early 1960s.
The San Diego Regional Water Quality Control Water Board, which regulates local water quality, charged gasoline giant Kinder Morgan Energy Partners with cleanup after the company bought the fuel depot in 1998. But Kinder Morgan recently finished sucking up and treating the last of the contaminated water, and destroying the network of wells it constructed to do so, confirmed Sean McClain, engineer geologist for the local water quality board.
“It’s one of the most successful cleanups I’ve seen,” McClain said. “The aquifer had … gasoline in very high concentrations, and now it’s non-detectable.”
The city recently finalized a long and complicated land deal with SDSU to redevelop the stadium property, but it retained rights to the water underneath. But in recent years the only attempt the city made to develop the water into a source was during its legal battle with Kinder Morgan.
San Diego sued the energy company in 2007, claiming the city should recoup over $100 million in damages for the gas contamination. A federal judge ruled the city couldn’t provide enough evidence that it was seriously considering the aquifer as a water source in the first place.
The city hasn’t used the Mission Valley aquifer for drinking water since 1936, U.S. District Court Judge Michael Anello wrote in a 2013 opinion, or made any plans to do so.
Despite the site’s long and dirty history, the water Kinder Morgan treats at its facility in Murray Canyon is good enough to throw back into the local creek – part of its remediation plan approved by the local water quality board. During litigation between the city and Kinder Morgan, local water quality board demanded to know why the city wouldn’t take that water, at least 500,000 gallons per day.
“Given the current drought condition and the city claiming they need this precious resource, why doesn’t the city … begin development of the Mission Valley aquifer?” wrote John Robertus, then executive officer of the Water Board.
The city responded that it had no reason to invest in the aquifer until Kinder Morgan finished the cleanup, according to a letter from J.M. Berrett, then-director of city public utilities.
San Diego’s current water leaders are pushing multiple multibillion-dollar projects intended to build water security, independence and diversification, like the $5 billion plus parallel pipe to the Colorado River and contractual obligations with expensive de-salted, drinkable ocean water.
Yet it’s ignoring a cheap resource beneath our feet. While San Diego technically isn’t in a drought since the atmosphere graced the region with a few wet years recently, 87 percent of the state is.
“I’d put a well down there, pump it once a month and let it sit there as an insurance policy,” said Wes Danskin, a U.S. Geological Survey hydrologist who’s kept watch over this aquifer for years.
The Pure Water Problem
Construction on the first phase of the city’s massive endeavor to turn sewage into drinking water just went out to bid in August. It’ll pump sewage from the city center at Morena Boulevard to the North City Water Reclamation Plant near University City.
The second phase, though, is supposed to produce the most recycled water and involves building a new purification treatment plant that’ll help fill a local reservoir in central San Diego by 2035.
The original plan, Stufflebean said, was to build that plant next to other waterworks hardware near the San Diego International Airport. But there might not be enough room to build the scale the city needs, Stufflebean said.
So the city is thinking instead of building a water purification plant on a piece of property it retained in the SDSU deal called the River Park Property. The city stipulated in its long and complex terms with the university that the site could be a potential location for future groundwater extraction wells.
Because the city retained its rights to the water, the university wouldn’t develop it on its own to serve whatever population eventually moves into new housing there.
The city will decide next year, Stufflebean said. But the city prefers the potential water purification plan site over the aquifer in Mission Valley because it already lies on the new pipeline route and wouldn’t involve building through a neighborhood.
Still, the city’s Pure Water plans don’t currently include developing the groundwater.
Kinder Morgan may still have operable treatment facilities it used to clean the water before dumping it into the creek – but it’s unclear if the city would be willing to take it over or build anew.
Kinder Morgan declined to comment for this story.
Stufflebean said the aquifer isn’t off the table.
“I’m not saying, ‘Not ever.’ Maybe it’s something to look into,” he said.
The story of the Mission Valley aquifer is really a story of San Diego’s origins.
It was the principal water supply for San Diego in the 1910s, until the U.S. Navy decided it couldn’t rely solely on groundwater, said Richard Jackson, a geological engineer who was hired by the city as a groundwater contamination expert.
“It’s just an idyllic area. It looked like Steinbeck’s California,” he said.
Jackson said he still gets quarterly reports on the aquifer’s water quality. His opinion differs from that of Danskin or McClain in that Jackson believes the aquifer has been irreversibly tarnished by the contamination and subsequent pumping it out.
“The aquifer now is more brackish (salty) than it used to be,” he said. “I believe it’s been compromised.”
Contaminated or not, Danskin of the U.S. Geological Survey said it’s a rare freshwater source that could withstand an earthquake better than any imported source via pipeline.
“There’s not a lot of water that would be a significant contribution to the city of San Diego’s needs, but there’s a local source … that might be beneficial to keeping critical infrastructure operational,” he said.
The aquifer is also fairly protected from sea water seeping into it as the oceans rise from human-caused climate change, a common consequence for many coastal aquifers in California, Danskin said.
“The value of water is hard to determine until you don’t have it,” Danskin said.