With more than 75,000 deer killed by motorists on New York roads each year, the problem of what to do with road kill is a big headache -- and expense -- for highway officials.

Now, Cornell scientists, teaming up with the New York State Department of Transportation (NYSDOT), are testing a promising and effective new method of disposal: composting.

Using a simple composting technique, the Cornell Waste Management Institute (CWMI) discovered it takes about a year to turn deer carcasses into compost that can be used for landscaping purposes along the very roadsides that were the animals' death sites. The cost of composting a deer: less than $25 a carcass.

Nationwide, deer-car collisions are an increasing problem, especially in rural agricultural areas, where fields and forests provide habitats and no natural predators to thin the population. Common disposal practices include hiring contractors to pick up and cremate the animals, hauling the carcasses to a landfill, burying them or dragging them into ditches off the road. But these methods are less than favorable from environmental and public health perspectives, says Ellen Z. Harrison, director of CWMI in the Department of Crop and Soil Sciences.

Increasingly, state, county and local highway departments are actively turning to composting to solve the ubiquitous deer problem. Already more than a dozen composting sites, called animal piles, have been established around the state, including one long "windrow" installed by the NYSDOT in Ulster County that, over time, has grown to contain 700 carcasses.

Composting animal carcasses is not new; chickens, pigs, calves, cows and even whales have been composted, according CWMI. Federal- and state-funded research conducted by Harrison and CWMI staff members Jean Bonhotal and Mary Schwarz shows that, for deer, passively aerated piles -- essentially elongated piles of wood chips in which deer carcasses are placed side-by-side -- are not only inexpensive but protect human health and the environment.

Microbial action in the pile causes it to heat up. Once the internal temperature reaches 110 degrees Fahrenheit, natural processes decompose the carcass within six months. The high temperatures and microbial processes during composting greatly reduce or kill most pathogens, minimizing the chance of spreading disease. It takes a year to make usable compost, according to Harrison.

"The deer problem is so expensive to deal with that NYSDOT has really taken the lead in looking for options that are environmentally sound, fiscally sensible and relatively easy to manage from a public and worker health and safety perspective," says Bonhotal, a senior extension associate.

Other collaborators on the project include the Transportation Infrastructure Research Consortium, Cornell Cooperative Extension and Cornell's College of Veterinary Medicine.

Starting this month, CWMI will hold a series of four workshops around the state to demonstrate the composting disposal method, and a DVD, fact sheet and poster are available. Visit http://cwmi.css.cornell.edu for more information.

Lauren Chambliss is a communications specialist with the Cornell Agricultural Experiment Station in Ithaca.