Back-end Upcycling: dog poop composting

(an old article, a version of which was published in Back Home Magazine in 2010-- updates coming soon)

To dog owners, it’s just a fact of life. What goes in must come out. Dog poop arouses ire in some quarters, has been the cause of many a neighborhood conflict and inspired municipal laws. Appropriate disposal of dog poop has come to be an emblem of good citizenship. Signs urging poop pickup and dispensers of small plastic bags for that purpose are a common sight in many public parks.

Some people wonder what all the fuss is about, in natural settings—after all, the ubiquitous plastic garbage that graces our forests and beaches will be around for what amounts to eternity (the shelf life for plastic being 650 years)- but poop is biodegradable, right?

Alas, in addition to being a social/aesthetic bone of contention, dog waste is a significant environmental problem. Based on amount of waste per dog and dogs per US household, experts estimate that our dogs deposit over six million tons of poop annually. Left on the ground, feces can take up to a year to decompose.

Nitrogen from feces (like sewage and fertilizer runoff) joins storm water runoff and eventually ends up in bodies of water. The result is eutrophication, in which excess nitrogen causes blooms of algae that deplete the water of light and oxygen and raise water temperatures, harming fish populations and aquatic plants. 

Dogs frequently carry organisms that pose threats to human health. Several, including coliform bacteria and encysted roundworms, can persist for a long time in the environment, either in water or in soil. Particularly in warm weather and in still water (puddles, lakes), bacteria can multiply and create health hazards. Pollution by bacteria attributed to canine sources (identifiable by DNA fingerprinting) is a major cause of closures of many beaches. 

Disposal of dog feces has become a problem for many large cities, giving rise to local ordinances and proposals for new solutions. While some cities and counties exhort citizens to send dog waste to the dump rather than leaving it on the ground, in many places it is considered problematic for landfills. It may constitute a large percentage of total volume, and plastic bags containing feces may remain intact for decades. Collectors object to the mess, smell and health issues associated with it. It’s also problematic in sewer systems, where it clogs the works and has necessitated additional equipment specifically to cope with it. 

Aversion to all manner of manure is common, at least among westerners, with the exception of farmers and one other growing demographic: gardeners. Many a gardener/dog owner has thought, “All this manure—such a shame to waste it!”

Composting is the practice, as old as horticulture, of mixing organic materials and facilitating their decomposition, usually with the aim of producing a soil amendment. A pile of composted or compostable poop quickens the pulse of many a gardener, knowing the magic worked by manure for growing a beautiful garden. Suburban and city gardeners may pay hard cash for bagged steer or chicken manure, bat guano or “zoo doo”.

In the past 20 years, numerous dog waste composting programs have arisen across North America and in Europe, with primarily environmental rather than horticultural aims: decontaminating dog feces and greatly reducing volume.

The area around Fairbanks, Alaska is home to many sled dog kennels, and the canine residents produce large volumes of feces that have caused environmental concerns. Since 1991, Ann Rippy and associates at the Natural Resources Conservation Service in Fairbanks, Alaska have worked with dog mushers in the area to compost dog waste from large kennels. The large volumes of dog waste produced have made it possible to achieve sufficient temperatures for efficient composting.

Alaska’s Denali National Park has been composting dog waste since 1980. The park has about 30 resident sled dogs, depositing about 50 pounds of poop daily. The resulting compost is used for ornamental plantings around the park, and also made available to the surrounding community for horticultural use.

In 1995 at Notre Dame de Grace Park in Montreal, Canada, a group associated with a dog run began a program to compost dog waste accumulated at the park.  The program was volunteer-run and by 2009 was managing 14 bins, each containing about 200 pounds of dog waste when full. The project produced about 2.5 tons of finished compost yearly, which was made available to local gardeners for use on ornamentals. The resulting compost was best described as a fertilizer due to its high nitrogen content, says Jim Fares, who was active in the project. However, the volumes of dog waste and the methods used were insufficient to achieve adequate killing of pathogens, and the volunteers eventually ran out of steam, so the project is now dormant.

In San Francisco, which may have more dogs than human children, dog waste disposal and recycling have been investigated by the city’s composting and waste collection company, Recology. Inclusion of dog waste in a methane digester project encountered some snags. Collection of sufficient volume, and exclusion of the ubiquitous plastic bags were practical issues, and initial tests failed to produce enough methane to make the enterprise financially viable. The project is now on a back burner, so to speak—but will continue to be of interest for future development.

Many cities across the US and Canada now have commercial dog waste collection services. Rose Seemann, association manager turned dog poop entrepreneur, founded Envirowagg and with her associates began dog waste collections in 2007. The idea was to take responsible disposal of dog waste to the next level—upcycling, (coined by McDonough and Braugart in their 2007 environmental book Cradle to Cradle): the transformation of a less useful material into a more useful material.

In 2009, the first bags of Doggone Good Compost became available for sale to gardeners, and sales continue in 2011. Envirowagg composting technicians use special equipment and careful monitoring to ensure high temperatures sufficient to reduce bacteria and parasites to levels acceptable to the EPA.  The company began marketing a new product, Doggone Good Potting Soil in 2011.  EnviroWagg sells its own brand of compostable dog waste bags at local pet stores and online, and also distributes printable eco-friendly bags to parks and open space departments.

Leon Kochian, a Cornell University biology professor, initiated a dog waste collection program with at an Ithaca, NY dog park in 2009.  Members of his dog owners association began collections at the park on Earth Day.  Dog waste is collected in compostable bags provided at the park, and deposited in special containers. The local composting company, Cayuga Compost, makes weekly pickups of the waste and composts it in combination with yard waste at their 4-acre facility.  The company hopes to produce safe, high-quality compost for horticultural use.  Proprietor Mark Wittig says they plan to test their first batch in spring 2011. 

Envirowagg’s Seemann and others involved in scientifically monitored dog poop composting contend that small-scale, DIY composting is unlikely to reach temperatures sufficient to kill pathogens, in part due to insufficient volume and in part due to lack of specialized equipment and expertise. For this reason, homemade dog waste compost is recommended for use on ornamentals and landscaping only.

Nevertheless, several companies now sell home composters intended for processing dog waste. Some of these incorporate vermiculture (earthworm composting); proponents say that worms will efficiently decompose and decontaminate dog poop.

In addition to composters, there is an array of products to assist in dog waste disposal. One of the most important for environmental and horticultural dog waste composting efforts is the waterproof, compostable bag. This allows people to collect dog waste in a convenient and reasonably sanitary way and dispose of it directly into collecting bins.  The Ithaca dog waste collection project uses bags made of GMO-free corn by BioBagsUSA, which also provides bags to restaurants for food waste compost collection.

Businesses specializing in dog waste collection have sprung up in many urban areas in the US and Canada. With Envirowagg leading the way, it seems inevitable that more of these businesses will take the next logical step and upcycle the waste into composted horticultural gold.