Thacher students find a solution to stinky problem Kimberly Rivers, Ojai Valley News correspondent Whether you ride them or just see them grazing in local pastures, horses seem to go hand in hand with life in the Ojai Valley. But there is another side to horses — literally, what comes out the other end. Manure. Managing manure is a necessary part of life for residential horse owners, ranches and boarding facilities in the Ojai Valley. Not only does it pile up quickly, it can also make its way into the Ventura River watershed. There, the nitrogen in manure is a pollutant, one that the Los Angeles Regional Water Quality Control Board has mandated must be drastically reduced in coming years. These new mandates have horse owners looking for solutions — and a team of students at The Thacher School may have found what those horse owners are seeking. They have created a system for manure composting, one that is workable for any number of horses. As part of a special senior project, the teens developed a process for composting the manure produced by Thacher’s 150 horses. The three-member student team at Thacher includes seniors Ben Chadwick, John Carey and Sasha Ongley. “Many see horse manure as waste to get rid of, but it is a very valuable resource,” said Ongley. “By composting it, you convert it to very nutritious soil. You close the loop and make your property more sustainable.” “We started with test runs, to see what kind of mixture would work best,” Ongley added. She explained there’s a specific balance of nitrogen and carbon that is required for the composting to work. “The nitrogen is in the manure itself, and the carbon is in the bedding in the stalls. We tested three different mixtures and ratios, and found the perfect one.” Ongley, Carey and Chadwick did smallscale test compost bins first. Those bins were about chest high and an arms-length wide. “They were small boxes; you can’t compost manure from 150 horses in one that size,” she said. Horses are a major part of the curriculum at Thacher, and a few years ago, students began to think about the environmental problems involving aspects of managing the manure. “It’s called the Kumana Prize. An alumni’s father set it up; he offered to donate a sum
of money each year to a group of students to implement a sustainability project,” said Ongley. The Kumana Prize began in 2012 by Thacher parent Sarosh Kumana. According to the Thacher website, funds are donated each year to support a student project focused on “the use of natural resources and furthering environmental awareness in the community.” Junior Thacher students apply in the spring for a project, which will be implemented during their senior year. Ongley said their manure composting project was inspired by a previous year’s Kumana Prize project, a bioswale. That project involved research which determined the nitrates and phosphates deposited in the creeks and rivers through run-off were creating an environment that was low in oxygen and high in algae blooms — which made it harmful for other aquatic life. The swale created a filtration process through various landscaping techniques using native plants, which was designed to “trap, slow and convey” runoff water to filter out pollutants and allow the water to seep down, rather than just run off. “Last year they did a bioswale on campus to decrease bad runoff water and help reduce pollution,” said Ongley. “Manure composting goes off that. We pay another company to take the manure off campus, and do God-knows-what with it. With our progressive school, it is a little ridiculous.” Ongley said they worked with the school’s director of buildings and grounds to obtain the proper permits with local government, and construction is under way on the full-sized concrete composting bin. Ongley said it is slated to be finished in mid-January. “We received the zoning clearance from the County of Ventura Planning Division under our existing conditional use permit,” said Ed Bennett, director of buildings and grounds at Thacher. “We received the building and safety construction permit from the County.” Both permits cleared in October. “The legal barriers were the biggest challenge … and a surprise,” said Ongley. “Getting permits approved — I didn’t know about the many regulations involved when you want to compost manure. The end product has to pass a bunch of tests.” She went on to explain the bin’s construc-
tion. “It is a giant concrete three-walled box. Once that is built, the process is fairly simple. Just take the manure that freshmen and other students clean out of the stalls, transport it to the site, fill up the bin,” she said. Ongley explained the bins will use the aeration method of composting. Their design does not rely on turning the pile, but will use perforated PVC pipe through the bottom of the bin, connected to a blower. In the tests, the blower was run by standard electricity, but in the actual project it will be solar powered. “Getting oxygen into the pile is a key component to decomposition,” Ongley explained. “The blower will pump air into the mixture every 30 seconds. You basically leave it for a month, check the temperature to make sure it’s getting hot enough for long enough, and after a month you have really nice rich soil. Getting it started, built, is more complicated than the actual composting process.” Got manure? Part of the Kumana Prize requires a community outreach aspect. Ongley said their project involves going out into the community of horse owners and boarding facilities to help educate and implement this process. “In Ojai, where horses are a big part of our community, our first goal is to reach out to ranches, private owners to encourage them to adopt this system,” Ongley said. “We will work with them to develop it. We will be available to physically help people who don’t have the manpower. We will volunteer to get it started.” She said they are also creating an informational pamphlet, which will have the instructions on how to get manure composting started. Once Thacher’s full-size bin is complete, the research will continue. “We will be doing tests of the runoff water before we begin composting, and when we are composting. We will examine the levels of nutrients in the composted soil and study whether we are being efficient in preventing pollution in the runoff,” said Ongley. After just one post on the Facebook page Ojai Community Network, Ongley already has a list of folks wanting to try it out. “I’m surprised by how much feedback we got. It’s great to see how excited the community is about it. If you have two or 20 horses, this can work for you,” said Ongley. To find out more about getting a manure composting system, e-mail srongley@ thacher.org.