Several groups have launched a campaign to urge Lake Minnetonka boaters to pick up and haul out trash during this final busy boating weekend of the season.

The Hennepin County Sheriff's Office, Lake Minnetonka Conservation District, state Department of Natural Resources, Lake Minnetonka Association, Three Rivers Park District, Minnehaha Creek Watershed District and Minnetonka Power Squadron announced the "Zero Waste" campaign at the end of August, urging people to leave behind zero waste on the Twin Cities' most popular lake.

It comes before the final big boating weekend of the year this Labor Day weekend and after trash piling up in the lake prompted concerns from local residents and leaders earlier this summer.

"Law enforcement and the LMCD can only do so much to fix the litter problem," Sheriff Rich Stanek said in a statement. "Lake residents, businesses and visitors all need to be a part of the solution by leading by example — that includes using common courtesy and abiding the law. We want people to enjoy the lakes, but we want them to do so responsibly and more importantly safely."

After the July 4th weekend, where boaters converge on Cruiser's Cove next to Big Island on the lake for parties, volunteers loaded up trash bags full of broken liquor bottles, beer bottle caps and other garbage found in the water or underneath, and the Lake Minnetonka Association ramped up volunteer cleanup efforts.

The conservation district discussed a wide range of ideas for attacking the problem, such as starting stiffer fines, adding civil penalties, installing a camera at Big Island, putting up a floating restroom or limiting the number of boats clustered around the island. Some of the ideas could be pursued in 2016, conservation district executive director Greg Nybeck said.

In the meantime, in late July, undercover officers did a stint at Big Island for underage consumption and littering with help from the DNR, giving out eight underage consumption citations; another undercover detail is planned before the end of the 2015 season, though the sheriff's office couldn't say when it would be. The Sheriff's Office has also put up three electronic boards near the lake reminding visitors not to litter.

Before and after the Labor Day weekend, crews will also test for E.coli in Cruiser's Cove. Litter and human waste have long been problems on Lake Minnetonka, the Twin Cities' largest lake. But while the conservation district, which regulates use of the lake, says it's a misdemeanor to litter — it comes with an up to $1,000 fine and/or 90 days in jail — it's difficult to enforce. A deputy can't issue a citation unless they observed littering or the person admits to it.

Broken bottles underwater can pose a safety hazard to swimmers wading in the shallow waters along the island and the trash also become a breeding ground for zebra mussels, which otherwise wouldn't have anything to attach to on the sandy beach.

That's why the groups behind the latest campaign are urging boaters and other visitors to pitch in, bringing trash bags, knowing where public restrooms are located and working together to preserve and protect the lake.

Kelly Smith • 612-673-4141