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Composting Toilets Save Water, Spark Conversation

Composting Toilets Save Water, Spark Conversation

By Becky Bach, San Jose Mercury News

SAN JOSE, Calif. — The most radical “green” features of the City of San Jose’s new Environmental Innovation Center are concealed behind two doors marked “Women” and “Men.”

There, plopped between the other conventional stalls, are two “composting toilets,” the first ever installed in a California office building.

“You assume you get an outhouse on a trail,” said Nora Cibrian, an environmental services specialist with the city. “But you just don’t think you can do it indoors too.”

These two toilets resemble every other commode, but at a total cost of approximately $20,000, they aren’t your great-grandmother’s latrines. They skip the sewage system entirely, funneling waste into a tank in the basement the size of a commercial trash bin.

Unlike an old-fashioned outhouse, where the waste goes straight into a hole in the ground, the composting toilets use the magic of chemistry to convert it to fertilizer. Just as in a backyard compost pile full of leaves and fruit rinds, the nutrient-rich waste mixes with carbon from wood shavings in the tank. Hungry bacteria then break down the material into tiny pieces, generating heat and carbon dioxide. A fan circulates air, reducing odor and ensuring the bacteria have plenty of oxygen. It takes some additional work to complete the yearlong composting process. You have to toss in some earthworms, sift occasionally, and add about a gallon of water per day.

When it’s all done, the city will have access to mature compost, according to toilet manufacturer Don Mills, a sales director for Clivus Multrum, a Massachusetts company founded in the 1970s by environmentalist Rockefeller scion, Abby Rockefeller.

“It’s not a highly complex device,” Mills said. “It’s a consciousness-raiser as well as an actual technology.”

The design team saw the toilets as a natural fit for the city’s new Environmental Innovation Center, a $31-million facility that includes a variety of Earth-friendly innovations, said city spokeswoman Cheryl Wessling. The toilets use just ounces of water per flush — just enough to moisten a biodegradable foam solution that coats the tanks before and after each use, and much less than the one to five gallons guzzled by average toilets.

“This is definitely a learning process,” Cibrian said. “We’ll see what works and what doesn’t work and whether it can be applied elsewhere.”

The Bay Area is home to two other composting toilet installations, both outdoors. One is at the Presidio’s El Polin Spring in San Francisco and the other at Crystal Springs Golf Course in Burlingame.

The Presidio Trust installed the composting toilets near the spring in 2011 to preserve a unique watershed with a rich archeological history, said Allison Stone, the organization’s director of trails and philanthropy. She admitted they were a bit nervous at first, but are now quite happy with their off-the-grid choice.

“It’s been a great experience,” Stone said. “We have not had any major problems.”

But despite the water-saving benefits, the composting toilets have one big drawback apart from the steep upfront cost that has limited their use: Governments still see the resulting compost as sewage, sharply limiting disposal options.

Though San Jose expects to approve permits soon for the unconventional toilets at the Environmental Innovation Center, city officials haven’t decided how they will dispose of the resulting compost. Wessling said it might be used on-site to fertilize the landscaping, or the city could have Clivus haul it away for $350 a month.

The Innovation Center’s new tenants are expected to pay the maintenance costs. They include: ReStore, Habitat for Humanity’s building materials store and donation center; a household hazardous waste drop-off facility; and Prospect Silicon Valley, which will run a program to help develop clean technology.

The Presidio Trust hired a contractor to regularly sift and care for the toilets and that contractor removed the waste, Stone said.

Vermont Law School installed composting toilets indoors in 1998 and gets numerous requests to see them, said Lori Campbell, the school’s facilities manager.

“People are fascinated,” she said.

But the compost disposal poses a big drawback that advocates face coast to coast.

“It is presently the case in nearly every state that you must regard this material as sewage,” Mills said.

Vermont state law still precludes the school from using the compost on its grounds, Campbell said, calling the restriction “unfortunate.”

“It’s beautiful compost,” she said. “It’s so rich, it’s unbelievable.”

Peter Scott, an emeritus professor of physics at UC Santa Cruz and California’s foremost expert on the commodes, believes the steep upfront cost chiefly dissuades many potential buyers. He first learned about the toilets while visiting the Vermont Law School in the early 2000s with his wife, Celia, a former Santa Cruz mayor, and he has been advocating their use ever since.

“It’s an interesting problem and an interesting puzzle as to why there aren’t more of them,” Scott said. “It seems like we have a lot of opportunities.”

Photo: Bay Area News Group/MCT/LiPo Ching

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Earthquake Cluster Likely To Strike San Francisco Bay Area, Scientists Say

Earthquake Cluster Likely To Strike San Francisco Bay Area, Scientists Say

By Becky Bach, San Jose Mercury News

SAN JOSE, Calif. — The Bay Area’s Big One will still be plenty big, but it might not be just one, according to a study released Monday by U.S. Geological Survey scientists.

A flurry of midsized quakes is more likely to strike the San Francsico Bay Area rather than a giant 1906-esque rupture, said David Schwartz, a paleoseismologist at the USGS’s Menlo Park office and the lead author of the study, which appeared in June’s Bulletin of the Seismological Society of America. The study marks the first comprehensive history of the Bay Area’s seismicity dating to 1600.

A quake cluster isn’t necessarily good news, as it could keep communities constantly cleaning up the earthquake damage, several experts said.

“It presents a very different problem in how you respond and recover from earthquakes,” Schwartz said.

After the 7.8-magnitude 1906 earthquake, the 20th century was abnormally stable, he said. Therefore, an earthquake cluster is overdue, the scientists said.

“Basically, what goes in, must go out,” Schwartz said. The region’s seismicity stems from the clash of two massive plates in the earth’s crust. The Pacific Plate is sliding northwest, while the North American Plate is moving southeast.

Since 1906, the plates have moved about 13 feet in the Bay Area. Like a compressed spring, they’re ready to burst.

In the Bay Area, the plate boundary fractures into a handful of fissures, all generally trending northwest-to-southeast. The well-known San Andreas Fault, which Schwartz calls the “master fault,” is accompanied by the San Gregorio Fault, the Hayward Fault, the Calaveras Fault and the Rodgers Creek Fault in the North Bay, among others.

Future quakes are expected to spread out along these faults.

“These faults are being stressed by the plate movements … and they all have to catch up,” Schwartz said.

The various faults “talk” to each other, said Roland Burgmann, an earth scientist at the University of California, Berkeley. “The communicating family of faults sometimes tend to rupture together as a group or shut each other off.”

The 1906 earthquake was likely a fluke, the perfect alignment of conditions that allowed 300 miles of the San Andreas Fault — from northern Mendocino County to San Juan Bautista — to release its pent-up pressure. This massive shaking kept the area unusually calm for a century, Schwartz said.

“Eventually, there should be more clusters,” Burgmann said.

The scientists based their prediction on the historical record, which shows a cluster of quakes shook the Bay Area from 1690 to 1776. At least six earthquakes, ranging from 6.3 to 7.7 magnitude, rattled the region’s major faults during that period, Schwartz said.

The cumulative release of energy from the quakes roughly equals that of the 1906 earthquake, Schwartz said.

“This is a summary of a tremendous amount of work,” said Greg Beroza, a Stanford seismologist who was not involved with the study.

Previously, other scientists had scoured the records kept by the Franciscan missionaries at San Francisco’s Mission Dolores starting in 1776, Schwartz said. He called the Spanish missionaries “the first seismographers.” They described the rumblings in their records, allowing scientists to assess the earthquake’s strength by extrapolating from the amount of damage the Franciscans described.

Scientists dated the earlier quakes by digging trenches and calculating the age of charcoal or other organic materials found several feet below the surface, Schwartz said.

This technique misses small or deep earthquakes, which don’t break the surface.

Although the scientists predict a group of tremors, rather than just a single, large earthquake, they admit the future could surprise them. The Bay Area has a 63 percent chance of one of more large earthquakes before 2036, according to estimates released in 2008 by the Working Group on California Earthquake Probabilities, a coalition of state, federal and academic geologists.

The USGS study provides a useful framework to plan for the future, said Thorne Lay, an earth scientist at UC Santa Cruz, who was not involved in the study.

Schwartz said he hopes to look back even farther than 1600 to more fully understand the Bay Area’s seismic history — and its future.

“The key question is when are we going to come out of the shadow, when are we going to go back to normal?” Burgmann asked.

AFP Photo/Frederick Florin