The good and the bad of pet waste

In honor of Earth Day, take a new look at pet waste. It can be used to produce energy in the form of methane. It's a myth, however, that dog waste will simply biodegrade without consequence to the environment. Recent studies put dogs third or fourth on the list of contributors to bacteria in contaminated waters across America. In surveys, a disturbing number of pet owners were unaware pet waste is harmful to the environment or simply didn't care, regardless of ordinances, fines or other consequences. Lake Tahoe does have an ordinance requiring pick up of dog waste.

With the seasonal arrival of tourists pending, it's timely to consider dog waste not only causes water pollution, but also neighborhood feuds, unsafe and unsanitary beaches, and messy, smelly boot bottoms on local trails. Simply cleaning up after pets helps prevent watershed pollution, protects aquatic life and eliminates the release of pet waste nutrients that feed the weed and algae growth which threaten lake clarity.

While urban wildlife, like geese, also produce waste, they eat local grasses and basically recycle when they eliminate. Foreign ingredients in manufactured foods eaten and eliminated by humans and their pets introduce pathogens which pollute both earth and water. In "Tahoe's Dogs Make an Impact on Lake Water Quality," Bruce Warden, a scientist at the Lahontan Regional Water Quality Control Board, explained how the estimated 15,000 Tahoe dogs produce about 90 tons of nitrogen and 15 tons of phosphorus per year. He pointed out dog waste doesn't normally go into sanitary sewers to be treated and exported out of the basin as human waste does.

Many public environmental agencies now are asking pet owners pick up and dispose of pet waste in a toilet if possible. Second best is to use a biodegradable bag and drop it into a the trash. Another alternative is a backyard in-ground digester like the Doggie Dooley, which is like a pet septic tank. Pet waste cannot be added to a compost pile because heat levels are not high enough to kill harmful pathogens.

The good news about pet waste is that experiments are ongoing to turn it into a viable "poop power" energy source. In 2006, the city of San Francisco experimented with collection devices which would create dog waste methane to generate electricity. In 2010, a public art project in Cambridge, Mass., succeeded in creating a people-friendly system which turns dog park poop into methane, powering a flame in an historic Beacon Hill lamp post.

The website for the Park Spark Project points out methane digesters are used in many places around the world for cooking, heating and lighting. They can use almost any organic materials, and large-scale digesters often use materials such as cow manure.

In Marin County, Calif., the Straus Family Creamery installed a methane digester in 2000. The creamery's manure-to-energy process saves the dairy thousands of dollars a month in energy bills.

As the snow melts, no one can deny poop piles do not go away on their own. So, as we prepare to welcome the world to Lake Tahoe, let's scoop the poop and help make our community a healthy, pristine place where people want to visit again and again.

• Provided by the Lake Tahoe Humane Society and Society for the Prevention of Cruelty to Animals to help "Keep Tahoe Kind." Dawn Armstrong is the executive director of the Lake Tahoe Humane Society and S.P.C.A.