Most people are picking up after their dogs at Aldergrove Lake Regional Park, but few are using the park's in-ground tank.

Instead they are filling garbage cans with plastic bags.

Metro Vancouver has been trying to figure out doggy dos and don'ts.

A doggie toilet at Capilano River Park has been rarely used since it was installed last year. The most popular option is proving to be a red dog-waste-only bin, piloted at Boundary Bay and Tynehead parks.

But that still involves plastic bags, and it's messy: the waste is collected by a private company which separates the dog poop from the plastic, sending the waste to sewage treatment and the bags to the landfill.

"Right now you're not allowed to put dog waste in the garbage stream, but everybody does, because we don't know what to do with it," said Gudrun Jensen, operations services division manager for regional parks.

About one million people visit Metro Vancouver regional parks every year. Of those visitors, about 35 per cent have one or two dogs, which every year drop an estimated 450,000 kilograms of waste - enough to fill 50 dump trucks - in the parks.

And that pile of waste only includes Metro's 22 parks, not municipal parks stretching from West Vancouver to Abbotsford.

Metro has been trying for about seven years to find a solution after waste audits found up to 70 per cent of garbage in park bins was dog waste, Jensen said. The concern is that dog waste is a hazard to park workers, because it contains pathogens and nitrogen.

"If we could deal with this one issue, it would have so many spin-off benefits," Jensen said.

She noted Metro will likely have to use a variety of measures to deal with waste, depending on the park location.

Degradable plastic bags aren't the answer, she said, because they break down into tiny plastic bits, which means the dog waste will eventually start to decompose and produce methane.

The doggie toilet, which is akin to a sandpit, likely won't be pursued, she said, although it seems to work better in urban areas where pets have been trained to use them.

The red bin project, which costs about $200 a week for two bins, would be costly but "well worth it for the benefits," while the pumpable in-ground toilet has shown modest success.

Eventually, Jensen said, the idea is to compost dog waste, but Metro doesn't have a facility in place for that now.

University of B.C. grad student Geoff Hill, a principal at Crescent Moon Co., who is conducting a study on composting dog waste in worm bins, said the results so far look promising. Composted dog manure, he said, would be nutrient-rich fertilizer that could possibly be used in regional parks, in planters or around new trees.

- With files from Kelly Sinoski, Vancouver Sun

Read more: http://www.vancouversun.com