Last year, New York City gave out 92,000 dog licenses, but community surveys conducted by the city health department have suggested the actual number of canines is usually five times higher than this official count. Do some quick number crunching based on the average urban canine, and these counted and uncounted dogs would defecate about 74 tons of poop per day — or 27,000 tons annually.
That mound of doo would rival the weight of 3,800 African elephants, and typically, this excrement winds up in a landfill where it releases methane, a highly potent greenhouse gas.
But in Battery Park City, dog owners have already composted nearly 5,700 pounds of pet feces since 2019 to help grow plants on roadside medians. That’s just over half a ton a year. This neighborhood program is now preparing to expand beyond the eight bins located in or around the area’s three dog runs.
By spring, the Battery Park City Authority, a government organization established in 1968 that manages land in the area that's owned by the Port Authority, will upgrade to a larger capacity composter that can handle as much poop as the neighborhood dogs can make. The goal is to divert all of its estimated daily 200 pounds (36 tons annually) of doggie doo away from landfills. Currently, it only composts around 10% of that.
Battery Park City uses a composting device called the Earth Cube. It fits up to three cubic yards. Staff routinely do temperature checks and tests for pathogens to make sure it's safe to use. When the park's composter is three-fourths full, it's ready for 12 months of curing before it becomes compost for planters in Westside Highway medians.
“So many people have dogs, so being able to have a system in place for dog owners to not have to rely on the plastic bags that go to the landfill or leaving it out in the environment seems like a really great model," said Dr. Rebecca Ryals, an agroecology professor at the University of California, Merced.
Pet poo is more than just aesthetic or a climate change problem. A pile of droppings left on a sidewalk can potentially have up to 23 million forms of fecal coliform bacteria per gram, and that can make its way into local rivers, drinking water supplies or the bottom of your shoes.
Organizers of the Battery Park City Dog Waste Compost Program think that their community program could be a model for a citywide system.
How the dog poop composting works
The composting stations in Battery Park City consist of a small green metal bin for dog waste. They’re roughly the size of an office waste basket. Residents can use a scooper with a long arm or recycled newspaper, both provided next to the receptacle, to pick up the feces. No plastic bags, even if they’re compostable, are permitted in the bin. Every day, employees who maintain the parks and dog runs empty the bins.
Recycled newspapers are collected from local buildings. Owners can use them to pick up dog poop, and the newspapers also act as a form of carbon to encourage the composting process.
The dog poop is then weighed to determine how much newspaper, wood chips, sticks or leaves must be added. This organic, carbon-filled material provides energy and encourages microorganisms, such as bacteria or fungi, to turn poop into compost. The ratio of poop to carbon must be 2-to-1 by weight.
“I think of it [composting] like lasagna,” said Ryan Torres, vice president of parks operations at the Battery Park City Authority. “We introduce the dog waste, and then we layer that with carbon, and then we collect more dog waste and then we add more carbon.”
Battery Park City's nursery is where the dog waste goes after it's collected.
Within a year, pet waste compost that has been tested to be safe by the Battery Park City Authority is used in planting beds in medians along the West Side Highway.
The problem with dog poop
One of the biggest challenges is what Torres calls the “yuck factor.” People are so disgusted by dog stool that they don’t want to bother with going beyond putting it in a plastic bag and getting it to the nearest garbage can. According to a Penn State survey conducted in 2018, about one-quarter of urban dog owners don’t even pick up their pet waste.
The bacteria in dog feces can cause diseases in their canine friends that can be passed along to humans. Roundworms and hookworms are commonly found in pet waste, and they can survive for weeks or even years in places like playgrounds and parks. Merely touching a contaminated surface could lead to worm eggs entering the body, and their larvae can pass through the skin.
A neighborhood pooch plays in one of the Battery Park City dog runs.
A pet may show no sign of carrying these parasites, but the larvae can enter human organs and sometimes cause tissue damage and conditions like blindness. According to the Centers for Disease Control and Prevention, 5% of the U.S. population is infected with Toxocara roundworm eggs, though the prevalence rises to 40% overseas.
Abandoned turds can also adversely affect the environment. When it rains, pet waste can get washed up into storm sewers, affecting the water supply. It contains high levels of nitrogen and phosphorus, which can contribute to toxic algae blooms. These events deplete the oxygen in local waterways, making it difficult for underwater life to survive and for fish to even breathe.
The problem is compounded further when the scat decomposes in the water and releases ammonia, which can potentially kill aquatic life.
A 2011 study of Midwestern cities found that dog feces were a “dominant source of bacteria in outdoor air in metropolitan areas.”
In the Baltimore area, a 2007 study from Salisbury University found that just over a quarter of the bacteria in the Patapsco River basin was a result of pet waste. The germs can make it into the air, too. A 2011 study of Midwestern cities, conducted by a collection of universities, found that dog feces were a “dominant source of bacteria in outdoor air in metropolitan areas.”
“When it’s [dog feces] directly in the environment like that, it’s a hazard,” said Ryals, the professor. “If there are pathogens present there, it’s directly going into the environment; it’s not breaking down.”
