The West’s megadrought is worst in 1,200 years. Los Angeles is taking wastewater recycling to the extreme
You don’t have to look further than Los Angeles in December for an example. With nearly 10 inches of rain, it was the second-wettest such month on record for the city, according to the National Oceanic and Atmospheric Administration.
But the dreams of drought remediation were dashed when it became clear the jet stream did not have more lined up in the new year.
Last month, less than a tenth of an inch of rain fell in Los Angeles, making it the eighth-driest January on record for the city. Halfway through February, things are only getting worse. This year is off to a record-dry start.
Park Williams, a climate scientist at UCLA and the study’s lead author, said it will take several years of above-average rain and snowfall to cut through the megadrought.
“It’s extremely unlikely that this drought can be ended in one wet year,” he said.
A rainy day saved for later
Officials in Los Angeles are acutely aware of the water fluctuations and are working to capture every drop possible.
Los Angeles County has dug several large, open dirt basins — known as spreading grounds — to absorb rainfall and recharge underground aquifers. The basins also take in water diverted from dams.
“When we know that we’re going to get significant storms in the LA area, we obviously work really closely with LA County flood control,” said Anselmo Collins, senior assistant general manager of the water system for the Los Angeles Department of Water and Power. “If they happen to have a lot of water stored in their flood control dams, they can release that water ahead of time; give it an opportunity to percolate and make room in those dams and the reservoirs to be able to collect the water that’s coming in at the same time.”
The water’s slow journey of filtering down through the soil into the aquifers also cleans the water, Collins explained.
“When we pump it later on, we treat it again, and then it goes into our water distribution system, and it will get treated again,” said Collins, noting LADWP’s rigorous water treatment program. “When you talk about water, it’s something very personal to people … it’s something you put into your body.”
Ultimately, Los Angeles is working to become less dependent on imported water. Currently, as much as 90% of water used in Los Angeles is imported from Northern California, the Sierra Nevada Mountains and the Colorado River Basin.
The plan, which is in progress, calls for 70% of the city’s water to be locally sourced by 2035.
“One of our major focuses is on recycled water and, in fact, this is a goal that the city of Los Angeles has, to recycle 100% of all wastewater,” said Traci Minamide, chief operating officer of Los Angeles Sanitation and Environment. “That will help us provide a local source of water that’s sustainable and consistent.”
And she does mean 100% of all wastewater.
“The recycled water is coming through the wastewater collection system, across our whole network of 6,500 miles of sewers. It’s coming from all the residents and commercial businesses,” Minamide said. “It’s all the stuff and then breaking it out and then cleaning it up after that.”
Minamide explained the water is treated to a very high purity — better than distilled water, she said — before it is supplied for groundwater infiltration, which is later pumped up, treated and used for drinking water.
LA Sanitation and Environment is already treating and supplying up to 12 million gallons a day to the aquifers, but Minamide said they are planning to boost the figure to more than 200 million gallons a day.
“Hyperion Water Reclamation Plant is one of the largest treatment plants in the country and that water right now is being treated and discharged. We’re just losing it out to Santa Monica Bay,” Minamide said. “There’s an opportunity for us to treat that water in a very advanced fashion under regulations, to a point where it can actually be used to help the water supply system.”
Sanitation and Environment also has other dry weather diversion projects aimed at capturing runoff on the city’s streets, cleaning up water and then offering it for irrigation locally. In other parts of town, the landscape is designed for the ground to absorb the water right where it is into aquifers and some renovations are required to factor in water conservation, for example, switching to permeable pavers instead of asphalt.
A ‘political and social’ question
As climate change continues to pound the region, leading to less rain and more excessively hot days, Los Angeles is using innovations to manage the city’s water needs down the line.
“Whether we will in fact manage it is a political and a social question, not a technical one. The technologies are there,” said Feldman.
While some projects slated to store much more water are years away, experts say it might have been harder to get legislation passed if residents weren’t on board. A couple of decades ago, voters might not have been willing to pay more in taxes to recycle water and capture rainfall when conserving water wasn’t a hot topic. However, now it seems the will is there.
Minamide pointed to data which shows more people are concerned about being wasteful.
“Despite the increase in the population over the past 20 years of roughly a million, we have seen our water use, and then our wastewater commensurately, actually go down,” Minamide said.
So people are saving water, but more could be done.
“I’d like to see for us to get smart on our end uses of water. Don’t use as much water for outdoor landscaping,” offered Feldman. “Think about ways of replacing and more efficiently using our appliances.”
In fact, the largest hurdle may be getting people to change how they think about water.
“Water isn’t free,” Feldman said. “Somebody has to go and acquire the water, treat it, distribute it to our homes and then treat the wastewater after it leaves our homes. We need to think about water as a precious commodity.”