Dog poo has a bright side

Dog poo is lighting a lantern at a Cambridge dog park as part of a month-long project that its creator, artist Matthew Mazzotta, hopes will get people thinking about not wasting waste.

The “Park Spark” poo converter is actually two steel, 500-gallon oil tanks painted a golden yellow, connected by diagonal black piping and attached to an old gaslight-style street lantern at the Pacific Street Park.

After the dogs do their business, signs on the tanks instruct owners to use biodegradable bags supplied on site to pick up the poo and deposit it into the left tank. People then turn a wheel to stir its insides, which contain waste and water. Microbes in the waste give off methane, an odourless gas that is fed through the tanks to the lamp and burned off. The park is small but has proven busy enough to ensure a steady supply of fuel.

Dog owner Lindsey Leason, a 29-year-old Harvard student, said she was all for seeing poo in a new light as she watched her two dogs play at the park.

“Since I have to pick up dog poo a lot, I think I’d rather have it be useful,” Leason said.
The project was funded by a $4,000 grant from Council of the Arts at the Massachusetts Institute of Technology, where Mazzotta earned a master’s degree in visual studies last year.

Indian example

The 33-year-old Mazzotta, who is not a dog owner, got the idea after he visited the park with a friend in 2009. Mazzotta had recently travelled to India and saw people there using poo in so-called “methane digesters” to cook food. As he watched the park’s trash can fill with bags of poop, he remarked to his friend, “In other countries, they use that.” A similar idea to use dog poo for power was floated in San Francisco about four years ago. But that idea fizzled in the city’s bureaucracy and over concerns about safety, said environmental scientist Will Brinton, who worked with Mazzotta on Park Spark and was consulted in the San Francisco project.

Cambridge Fire Chief Gerry Reardon had his own questions about “Park Spark”, including whether vandalism or poor design could cause the tank’s insides to spill out and how the methane would be safely contained and vented. But Park Spark’s sturdy build and safety features persuaded the fire department to give its approval, he said.

“We try to stay progressive here,” Reardon said.

Practical benefits

The practical benefits of the exhibit aren’t lost on Mazzotta. Burning the methane, which is 30 times more potent as a greenhouse gas than carbon dioxide, helps the environment, he said. And with dogs dropping tons of poo in cities everywhere, he thinks the idea of using its untapped power has broad appeal.