Experts contend pet ‘deposits’ pose pollution problem

Published 3:52 pm Thursday, April 30, 2009

When Daisy and Digger dally on their daily doggie walks, they produce a surprising amount of bacteria-filled waste, adding up to as much as 150 tons a day in Washington alone.

According to the state Department of Ecology, all this pet waste can cause serious environmental harm unless it is properly controlled.

"In an area of 100,000 people, about the size of Everett or Yakima, dogs generate about two and a half tons of feces per day," said Ralph Svrjcek, a water cleanup specialist for Ecology. "That’s almost two million pounds a year. That's a lot of bacteria."

Studies show about half of all dog owners walk their dogs in public places, and up to 40 percent of them don’t pick up after their pets.

Dog and cat waste left on the ground can be washed into storm sewers, most of which drain directly into natural water bodies. There the waste contributes to all sorts of problems - from sick kids to mucky algae that suffocates fish and is sometimes poisonous to humans.

"It seems like such a small amount when it's just your dog, but it really does add up," Svrjcek said. "Many people don't realize how important it is to take care of their pet waste so it stays out of our lakes, rivers and streams."

The same bacteria that make pet waste dangerous to people in parks can make water unsafe for swimming or drinking. Children and others can get sick if they dunk their heads or accidentally get a mouthful of polluted water. And when waste gets into shellfish beds, it can make clams and oysters unsafe to eat.

Children and others who play in yards or in parks where pets do their business can pick up illnesses from disease-causing bacteria and parasites. These include diarrhea, fever, muscle aches, headaches, vomiting, roundworms and toxoplasmosis (a parasite carried by cats that can cause birth defects if a woman becomes infected during pregnancy). Other pets can get sick, too.

So, what should a responsible pet owner do?

"Don't just throw your dog's business over the fence," Svrjcek warned. "Yes, it will biodegrade eventually, but meanwhile it can cause problems for the rest of us."

Cleaning up after pets can be as simple as taking along a plastic bag on your next walk. The "used" bag can be disposed safely by securing the plastic bag and putting it in a nearby trash can. At home, larger volumes of pet waste should be double-bagged to ensure it can be safely handled by local sanitation workers.

Many wastewater treatment plants allow pet waste to be flushed down the toilet (just the waste, not the litter). Check with the treatment plant first, though.

Homeowners who use septic systems should use another disposal method for pet waste. For example, pet waste can be buried in the yard, at least six inches deep, away from vegetable gardens, lakes, streams, ditches or wells.

"Even in rural areas, if you leave your pet's waste to decay in your yard, try to make sure it doesn't cause a water pollution problem," Svrjcek said.