Operators of Santa Fe's sewage system are taking the phrase "waste not, want not" to another level.

The wastewater-treatment plant lets homeowners, landscapers and others haul off a nutrient-rich compost made from discarded wood chips and human waste.

While the source might make you squeamish, said Bryan Romero, city Wastewater Division director, the soil amendment can help promote plant growth and reduce water use on landscaping.

Compost has been for sale at the treatment plant for more than a year, but getting out the word that the plant's operators believe it's safe and useful takes time. That's why Romero proposes next month to give away some of the compost to city residents.

If the City Council approves his plan today, the division will issue coupons to residents that can be redeemed for up to one cubic yard of the stuff.

"It's providing a sample so that people can try it," Romero said. "I use it at my house and lots of city employees are using it. We want to advertise it more."

The process of treating wastewater from Santa Fe toilets and drains leaves two byproducts: water and solid waste.

While treated water from the sewage plant southwest of the city runs down the Santa Fe River into the Rio Grande, the city has to find other outlets for the thick sludge. Most of it is injected into the ground at a field near the Santa Fe Municipal Airport. But about a third of the sludge is combined with wood chips and converted into compost in a facility that opened last spring.

In addition to providing a space for the compost, the new $11 million building also contains two dewatering machines that help reduce the effect of sludge injection as required by environmental regulations, Romero said.

The compost sits on a warehouse floor or outside for more than 90 days to cure before it's released to the public. Temperatures inside the compost piles, called windrows, reach more than 131 degrees during the first two weeks of active curing phase. Then, microorganisms keep working to reduce a pile's mass by up to 40 percent over the next couple of months.

Lab technician Patricia Rosacker is in charge of making sure the compost isn't gross. She performs routine tests to establish that levels of fecal matter are below standards for compost to be resold.

"It's done to show that if it's used in your garden, it's not going to be harmful," she said. "All that is left is the good part. Everything is decomposed to the point where it becomes a soil amendment."

The city performs other tests on the material, including a "marigold test" that ensures plants can germinate and mature in the soil.

City parks and the state Transportation Department projects have used truckloads of the material. Richie Caldon, one of the owners of Caldon Seeding and Reclamation, said his business also buys compost from Albuquerque's wastewater-treatment plant. Both facilities sell compost that is certified for Department of Transportation jobs, he said.

"We've been really happy with the compost that we have purchased," he said. "As far as revegetation, it really does help with germination of the seeds."

Although the Albuquerque-based business specializes in reclamation in Northern New Mexico, he said his family also farms land in Southern Colorado.

Sherman Bilbo, a supervisor at the operation, said he thinks it's good that the operation uses wood chips from the Santa Fe Solid Waste Management Agency as well as the sludge left over from the wastewater-treatment process.

"It takes two wasted things that were not being used," he said, "and makes a viable, usable product at the end."

Since April 2010, the facility has sold 2,651 cubic yards of compost and earned about $26,065 in revenue.

Contact Julie Ann Grimm at 986-3017 or jgrimm@sfnewmexican.com.

CITY COMPOST

Compost is available at the city of Santa Fe's wastewater-treatment plant, 73 Paseo Real, between 8 a.m. and 2:30 p.m. weekdays. The cost is $11.50 per cubic yard for screened compost, $9 per cubic yard for unscreened compost and $6 per yard for rough compost. City officials are expected next week to consider issuing coupons for free compost to water customers. For more information, call 955-4650.