Two studies that examine the environmental impacts of cattle carcass disposal are now available for review at the NDEQ web site, http://deq.ne.gov. One study focuses on potential water quality impacts, and the other examines potential air emissions, specifically methane and carbon dioxide. Both studies were conducted by the University of Nebraska through a contract with NDEQ.
The study ”Potential Water Quality Impacts Originating from Land Burial of Cattle Carcasses” can be found at the DEQ web site by selecting Publications, then choosing Waste Management, and then selecting Reports. The study ”Methane and Carbon Dioxide Production from Land Disposal of Cattle Carcasses” can be also found at the DEQ web site, under Publications/Waste Management/Reports.
Several years prior to the two new studies, NDEQ and the Nebraska Department of Agriculture had been involved in disaster planning that related to the disposal of animal carcasses. The agency developed a plan that examines the best disposal procedures if a catastrophic event resulted in large livestock mortality rates. In 2004, NDEQ’s conclusions were, and continue to be, that proper on-site burial of animal carcasses and landfill disposal are acceptable options for carcass disposal.
During the development of this Catastrophic Animal Mortality Management Plan, NDEQ found that they could not find studies that examined the environmental impacts of carcass disposal. For that reason, NDEQ subsequently decided to contract with the University to analyze these impacts.
“These two new studies will be a good reference resource, particularly if there is an instance of extensive livestock mortality in the future,” said Bill Gidley, NDEQ Waste Management Section Supervisor. “After reviewing these studies, our recommendations on carcass disposal continue to be the same, but the results reinforce our advice that care needs to be taken with carcass burial, and proper procedures should be followed.”
The air quality studies did not present any unexpected results, Gidley said. It was known that carcass disposal would cause emissions of methane and carbon dioxide. The study confirms this and provides quantitative information regarding the amount of these emissions. This information would be useful in predicting the potential air impacts after an extensive livestock disaster, Gidley said. The study indicated that methane emissions from cattle disposal were roughly equivalent to the types of emissions that would occur from a similar amount of food waste disposal at a landfill, and that the overall amount of methane generated from carcass disposal would constitute less than 1% of total emissions from agricultural operations.
The water quality impacts study indicates that the leachate (the liquid that seeps from the disposal site) from burying cattle consistently contained detectable amounts of antibiotics and hormones. The report states that the “concentrations of steroid hormones, antibiotics as well as other conventional contaminants detected in the leachate from cattle carcass disposal is of concern, especially as many on-farm animal carcass disposal sites are not lined.”
Gidley said that these findings reinforce the agency’s advice that those disposing of cattle carcasses need to find a proper burial location that is not close to a drinking water source. Procedures should be followed to ensure burial does not impact groundwater.
Gidley said the two studies supplement the recommendations that NDEQ made in the 2004 Catastrophic Animal Mortality Management Plan. This plan was originally distributed to local emergency planning officials across the state, and has also been provided to those who are considering carcass disposal options. People who wish to receive a hard copy of the animal mortality management plan can contact NDEQ at firstname.lastname@example.org.