What A Lake's Rebirth Has To Do With Human Waste From LA

Every day, truckloads of L.A. County sewage sludge end up in the southern San Joaquin Valley. A facility called Tulare Lake Compost transforms human waste from the Southland into nutrient-rich fertilizer.

But now, the lake’s once-in-a-generation return is threatening to flood its namesake operation.

If that happens, partially treated human waste could contaminate the lake water and surrounding farmland.

As a precaution, plant managers first reduced sewage shipments by half. Beginning this week, shipments will cease altogether.

Los Angeles County Sanitation Districts runs the plant near Kettleman City. According to spokesman Bryan Langpap, nearby levees should hold flood waters back and protect the facility.

“In prior big flooding events, all the floodwaters have been held back to the east,” Langpap says, adding that the compost plant sits above surrounding farmland. “And so even if those levees were to be overtopped, the surrounding land would have to fill up 5 feet before water could reach our facility.”

The risk to farms

But a record-shattering snowpack means southern Sierra Nevada snowmelt could fill the lake to levels not seen in more than a century. Water managers have cautioned downstream communities to prepare for the worst as the region’s patchwork of agencies coordinate flood-control plans.

The risk may prove too great for neighboring farms.

This week, Kings County Supervisor Doug Verboon announced a dam may be built around the 14,600-acre property. Flood water could then be sent to the land and contained there, helping to relieve pressure on levees.

“We’re gonna make sure that whatever water is put on that property, stays on that property – not to contaminate their neighbors,” Verboon recently said on KQED’s Forum, a public affairs show.

Verboon says the J.G. Boswell Company doesn’t want the contamination potentially spilling over onto its property. The farming giant would help construct the dam, he said.

Why L.A. Sanitation may choose to flood its lands

Langpap, of the sanitation district, says the agency is open to the possibility of flooding its land to help the county and struggling levees.

“We’re a public agency, and our mission is to protect public health and the environment. That mission doesn't change wherever we are in the state,” Langpap says. “We want to be good neighbors, whether we’re in L.A. County or Kings County.”

In normal years, the facility uses compost generated at the plant to fertilize surrounding fields, where grain is farmed and sold to dairies and ranchers for feed.

The compost plant also helps the Valley by using massive amounts of agricultural wood chippings, Langpap says.

“In the past, that wood waste would have been burned by farmers, which creates air pollution in the local area,” he says.

Plant managers are working to process all remaining waste into compost by mid-May, before the hottest months of summer.

More about the facility

An overview of the Tulare Lake Compost facility in Kettleman City indicates four key steps: 1. Hauling trucks arrive with waste) 2. Mixing (waste is unloaded and stored temporarily outdoors) 3. Composting (blended materials are laid out to break down). 4. Screening (product is passed through screens to produce a consistent result.)

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Courtesy L.A. Sanitation

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Quick facts:

• L.A. County bought about 14,600 acres near Kettleman City in 2006
• The compost facility makes up 175-acres of that land
• The remainder of acres are leased to a farmer
• Tulare Lake Compost can "convert up to 100,000 wet tons per year" of waste into "Class A Exceptional Quality compost. "