Compost Requirements

Preventing Animal Nuisances in Backyard Composting

Backyard compost piles can become a source of food and shelter for rodents (including rats), raccoons, skunks and household pets if compost is not managed correctly. Many of these pests carry a number of diseases and internal parasites that can cause infections in humans. For instance:

• Raccoon roundworm, an infection spread to people by the accidental ingestion or inhalation of roundworm eggs from raccoon feces, can cause serious disabilities, and young children are thought to be most susceptible. Raccoons are also carriers of rabies.
   
• Among the diseases rats can transmit to humans are leptospirosis and salmonellosis.
   
• Skunks are known to carry rabies and have been shown to carry other viral diseases such as canine distemper, listeriosis and tularemia.

Compost Management 

Good compost management can deter pests and reduce human exposures to bacteria, viruses and parasites that pests may carry into our environments. Reducing food odors and flies, or eliminating attractors, like food scraps that become exposed in poorly managed compost piles, is the best defense against attracting unwanted insects and pests to your backyard and preventing exposure to pathogens.

• Do not add meat, chicken, fish, oils, cheese or leftovers containing excessive oil or seasoning
   
• Do not add feces of carnivorous pests, including cat litter, to compost piles. (This will reduce the probability of adding parasites which can be present in feces.)
   
• Avoid exposing food scraps. When adding appropriate scraps: First, add yard waste around inner wall of bin; then add food scraps to center of pile and cover them with layering material such as grass, leaves, soil, sawdust
   
• Turn the compost pile and keep it moist - This increases the temperature and speeds up decomposition
   
• Practice good bin-keeping – be observant and correct issues before they can cause problems

Pile/Bin Location 

Locate compost piles/bins away from possible food sources and nesting areas, such as garbage cans, fruit trees, berry bushes, sheds, woodpiles, or brush piles.

Pest-Proof Your Bin

Rodents and other pests are able to burrow under and into compost bins or chew their way through them. Take steps to prevent access to your compost pile/bin. Compost bins should be designed with this in mind. Some possible designs include:

• Construct a bin out of half inch hardware cloth or welded wire
   
• Wrap the entire bin in ¼ inch to ½ inch wire mesh. If your compost bin has vents, it may be necessary to cover them with wire mesh
   
• Line bins with wire mesh, including vents
   
• A secure, tight-fitting lid is required
   
• Cover a wooden pallet with ¼ inch to ½ inch wire mesh, then place and secure bin (with wire mesh lining) on top of the pallet

Loose compost piles that contain food scraps or other food waste products are an attractant for pests and create a public health nuisance for the community.

Food Waste Drop-Off

A food waste drop-off area is located at the Recycling Center and is available to Portsmouth residents during normal operational hours. Click here for full information. 

Additional Information

Additional information/resources on backyard composting can be found at the UNH Cooperative Extension:

Composting for the Home Gardener 

Can you compost in the Winter?