Is composting dog waste worth the risk?
March 17, 2012
A typical dog puts out 274 pounds of waste per year, about three-quarters of a pound per day, according to Environmental Protection Agency estimates. Dog waste pollutes ground and surface water, attracts flies, smells and transmits parasites and infectious diseases. Natural Resource Conservation Service research suggests dog waste can be composted and become a safe soil additive if temperatures get high enough during composting to kill parasites and disease organisms (pathogens). It’s essential to carefully follow the process below to ensure that the resulting compost will be safe to use.
Making compost requires nitrogen-rich components such as dog waste and green grass clippings. It also requires carbon-rich materials, such as sawdust, chopped straw or hay, shredded newspaper and fallen leaves. Containing the material in a bin should help the mix get hot enough to kill pathogens and parasites. Try to keep the pile at least 3 feet by 3 feet by 3 feet (or 1 cubic yard). Since one of the most important factors in safely composting feces is heat, invest in a good-quality long-stemmed thermometer to monitor internal compost temperatures.
Choose a sunny, dry site for the bin, somewhere where runoff from the pile won’t flow to contaminate a garden, a children’s play area, a stream or a dog run. Take two shovels of dog waste (or one of waste and one of green grass clippings), one shovel of sawdust or other carbon-rich material and mix thoroughly, adding water in small amounts until the ingredients are as moist as a wrung-out sponge. Continue adding ingredients until the bin is full. Once the bin is full, do not add additional materials. Keep it covered and let it cook.
Insert the thermometer daily into several parts of the mixture in the bin, including the center, and record the temperature. If you do not see a rapid rise to 160 degrees F and then a gradual decline of internal temperatures, adjust your recipe. More nitrogen-rich material, particularly green waste, will make it hotter. Compost must reliably reach 145 degrees for several days to destroy pathogens. When the temperature drops (usually in about two weeks), turn the mixture, mixing the outside to the inside. Check the temperature again daily. Repeat the turning process until the temperature stops rising after turning. Cooking time varies from six to eight weeks. If the compost gets too hot, it could ignite. Add water to drop the temperature quickly.
However, before you decide to compost dog waste, make sure you are willing to do the work needed to make it safe to use.
For complete information on compost dog waste, including designing different bins and piles see: ftp://ftp-fc.sc.egov.usda.gov/AK/Publications/dogwastecomposting2.pdf.