To Fight the Drought, California Is Turning Sewage Into Drinking Water
A few weeks ago, a storm blew over Southern California, and a light snow dusted the San Gabriel Mountains. It melted, and the meltwater ran into the San Gabriel River, which tumbles down the granite peaks until the land flattens out onto the broad basin below, home to about 15 million humans, the largest metropolitan area in the U.S. after New York. Some of the water sank into the usually dry riverbed, but most of it ran into old gravel pits called spreading grounds. The spreading grounds act as filter and sponge, trapping the water, soaking it up, and sending it as much as 2,000 feet underground, where it’s banked into one of about 15 aquifers below the basin. Several dozen gigantic straws pump the water back up and into the taps and toilets of nearly 5 million residents in 43 cities. Azusa, Pasadena, West Covina, Baldwin Park, El Monte, City of Industry—all are fed this subterranean mountain water, which is sipped up and shat in and cooked with, flushed and drained, and then, as sewage, runs out to sea.
But the wastewater’s natural, gravitationally assisted course through the sewer and out to sea ends in the narrows near Whittier, a suburb east of L.A. The San Gabriel and another river, the Rio Hondo, which run parallel to each other through much of the basin, both flow through the narrows and back up against the Whittier Narrows Dam. Here they are channeled and fully tamed. The Army Corps of Engineers, which completed construction of the dam in 1957, deemed it “the central element of the Los Angeles County Drainage Area flood control system.” Before the dam and channelization, during the very occasional, very heavy rains that hit Southern California in El Niño years like this one, the Rio Hondo and the San Gabriel became one mega-river, sweeping to sea everything in its path, sewage included.
The solution to the sewage problem, the flooding problem, and in part, the worst drought the state has seen in maybe 1,200 years, lies a few miles east of the Whittier Narrows Dam, in the shadow of what was once the largest landfill in America, in the offices of the Metropolitan Sanitation Department of Los Angeles County, in a cubicle surrounded by pothos and philodendron, arrowhead vines and Chinese evergreen. His name is Earle Hartling. He stops the sewage, takes the water out, and uses bacteria, sand, coal, and time to filter it back into a spillway along the creek, where it returns to the river and flows into a nearby spreading ground, sinks and seeps and enters the aquifer and the drinkable water supply. And the cycle, minus the mountains and the snow, repeats.
“We’ve been drinking recycled water indirectly for 50 years,” Hartling told me when we first spoke. I’d been curious about California’s efforts at recycling water ever since visiting Singapore and learning about the country’s extraordinary efforts to capture and recycle its water—even launching an aggressive marketing campaign to promote drinking its treated sewage. “Oh, you mean NEWater? Yes! Yes.” Hartling said, chuckling. “Have you tasted it?” I had. “It tastes awful. Like nothing.” This was true. Everything tasty about water comes from the minerals that surround it; very pure water tends to feel funky and incorrect. Too pure wastewater recently pulled arsenic out of surrounding clay sediment when it entered an aquifer in Orange County; 100 percent pure water is extremely dangerous, even deadly.
In Orange County, the solution to the too pure water problem had been to add quicklime and other calcium-rich substances to the purification process. But the seep of the spreading grounds accomplishes this step naturally. The water, whether it be recycled or washed down in a storm, “loses its identity underground,” Hartling said. Then he paused and added, “I apologize. My math earlier was off: We’ve actually been drinking recycled water for 53 years.”
Hartling has been the water recycling coordinator for the Metropolitan Sanitation Department since 1995. When he started, in 1981, the department had 11 reuse sites (meaning areas where recycled water was delivered through a meter), typically located in a park or a cemetery, the landscaping along street medians, at a construction site, or in industrial facilities (particularly nearby in the City of Industry). The county is now up to 805 reuse sites, still mostly for medians and golf courses but also some agriculture. Behind Hartling's office is the San Jose Creek Water Reclamation Plant, the largest water recycling plant in L.A. County. Some 260 million gallons flow into and out of it each day. Nine more recycling plants are scattered throughout the basin and up in the hills to the northeast. All told, they deliver up to 10 percent of the annual water used by Los Angeles County (excluding a few cities, most notably the city of Los Angeles, which is overseen by the Department of Water and Power). That percentage is growing, and the amount of water recharged, or returned to the aquifers after use, is growing too.
Of the many water problems facing the state of California and the whole of the West, among the most persistent is that so much of life, particularly in urban areas, is lived divorced from the thing itself. Water comes from either deep below ground or faraway mountains, or every so often, it fills up and spills out of otherwise dry riverbeds. This is, perhaps, why the future of water use along the coast often focuses on the most tantalizing water source of all: the ocean. But desalination is expensive, not simply because taking the salt out of saltwater requires a lot of energy and is environmentally dubious but because by definition the plants exist at sea level, and so the freshwater must travel a reverse course, uphill, which requires still more energy, which means more money. Even Israel, the country that invented desalination and is the technology’s greatest exporter to the world, obtains nearly a quarter of its water via reuse and recycling and is on track to outpace desalination within the decade. (An astonishing 86 percent of water used for agriculture in Israel comes from recycled, treated sewage.) In Singapore, recycled water makes up more than 30 percent of supply. Los Angeles County, at 10 percent, has room to grow.
Allowing clean water to naturally filter into underground aquifers isn’t simply energy efficient and cheap—it banks underground water we’ve been overdrawing for a century, long enough to cause the ground in parts of the state to sink. L.A. County is one of the oldest water recyclers in the world, and the L.A. Basin contains the highest volume of recycled water in a concentrated area in the state, accounting for nearly as much as the whole Central Valley, which is 10 times its size. Though irrigation still accounts for the majority of recycled water in California, its use in agriculture has leveled off significantly in recent years. There’s a simple reason for this: efficiency. As growers adjust to spot and drip irrigation, as they use less water overall, there’s simply less runoff to draw from and recycle.
The same will be true among residential users—we’ll reach a kind of inflection point where our flushing and washing and cooking and gardening and drinking water use is perfectly matched by the recycling facilities, and we will have eked as much good water back out of our standard levels of sewage and runoff as is possible. Only then, Hartling told me, will desalination make sense. "Oh, it'll be a long time," Hartling said when I asked him when Southern California will hit peak recycled water. "But if I could predict the future...," he said, shrugging. For now, L.A. County recharges about 50,000 acre-feet of recycled water per year, which is enough for about half a million households annually (an acre-foot is a foot of water in an acre, which is roughly the size of a football field). In rainy years, this spikes. From 2010 to 2011, the county recharged about a million acre-feet from recycling and runoff combined, enough for about 10 million households. The majority of the county’s water still comes from elsewhere—the Colorado River or the Sacramento Delta or the Sierra Nevada. On the open market, a million acre-feet of water can be worth about a billion dollars. This winter is expected to be extremely rainy—perhaps rainy enough to capture, recycle, and recharge more than a billion dollars' worth of water in just a few months.
After Hartling and I spoke on the phone, he invited me out to the Whittier Narrows to visit him at the plant behind his office in the shadow of the landfill that’s now a park. We lingered over his jungly cubicle. He had a bumper sticker on the side that read, “I *heart* recycled water.” Then, as we wandered out back, he explained why it was that L.A. had one of the oldest water recycling systems in the world.
The primary problem, or fear, was sewage. After World War II, as the population within the basins exploded and houses and freeways crept back up toward the foothills of the mountains, there was a real concern that all the new sewage from the new residents would overwhelm the systems closer to shore. Remember, everything moves out to sea—including the soil. The basins do act like bowls, and the clay sediment that’s piled up near the shoreline prevents water from seeping underground. Recycling at a sort of midway point between the mountains and the sea, in narrows like in Whittier, removed much of the liquid bulk from the sewage at a natural and easy access point to the aquifers. You could remove the water, clean it, and bank it, cheaply. “We killed two birds with one stone,” Hartling said, grinning. “The sewage problem and the water problem are solved right here.”
By now we’d reached the plant, which was really just a series of pools extending out across a few acres. Mallards were paddling, muttering like happy old men, in one of the pools nearest us. This was one of the cleaner areas, among the last stops on the water’s journey before reentering the spillway, the river, and the ground. We walked alongside the water to where the sewage came in. I told Hartling I was surprised: It smelled like almost nothing. “You’ll catch a sort of earthy musty smell occasionally,” he said. He lifted up a metal trapdoor, and we stared into the gloom. A wave of bad tang hit me. “Here’s where we skim the suspended solids, or sinkers and floaters, as we call ’em,” Hartling said, closing the lid and adding, “It’s sort of gross.”
Once the water is scraped of shit, it enters a series of bubbly, churning pools filled with bacteria, which go to town on all the organic matter. This was where the earthy smell came from, and Hartling and I gazed at the burbly chocolate-brown mess for a while as he explained how the flows at this plant, which handles some 62.5 million gallons a day, have been steadily decreasing as folks have converted to low-flush toilets and efficient washing machines. The daily flows are at the same levels as in 1968, even though the population has increased by more than 40 percent since then. Flows peaked, Hartling said, in 1989 and again in 1998, owing to the last El Niño. But they’d soon be handling more water, not just because of all the rainfall coming but because the agency recently received authority to recycle the runoff from storm drains, too, which it hadn’t been able to do before.
We walked back along the pools with the mallards, where the water was again skimmed before entering its final step, a charcoal and sand purification, with a little chlorine and ammonia added. This was necessary, Hartling said, because once they’d begun putting water into the San Jose Creek, people started playing in there, and the area had been designated for recreation. He took me over to the discharge point, where the water hit the soft-bottomed creek bed. Hartling often went walking along this waterway and saw people swimming in there, bathing, cleaning their laundry, paddling, fishing. He liked knowing that what they were in was a lot cleaner and safer than what had come straight down from the mountain and through the flat plain and all the suburbs. And that soon enough, it would reach the spreading ground and work its way down to the aquifer, and the cycle would repeat.