With the purchase a high-pressure boat-washing machine this summer, lakeshore property owners on Green Lake in Kandiyohi County ramped up their long-running attempt to keep their favorite body of water free of zebra mussels.

Ron Schneider, vice chair of the Green Lake Property Owners Association, believes his group is the only lake association in the state to purchase a boat washer.

The Department of Natural Resources has a small fleet of the cleaners, which are moved from lake to lake as necessary.

Schneider said the $18,000 machine will be stationed this summer at the Saulsbury Beach boat launch site in Spicer, Minn., on Green Lake’s shore.

“We hope to buy several more,’’ he said, noting that Green Lake has six public launch sites.

In existence 50 years, the property owners group has learned a lot about aquatic invasive species (AIS) since its formation, and even more about politics.

Initially, the group thought the DNR would aid its cause by more intensively isolating lakes infested with zebra mussels, Schneider said. The group was similarly naive when it first approached the Legislature for help.

“We were told we needed a lobbyist,’’ he said, which his group subsequently hired.

Unlike some lake associations, the Green Lake group seems united in its willingness to do whatever is necessary to keep their lake mussel-free. With about 800 property owners, the group asks annual dues of $100 apiece.

“The big expense is staffing the washing machine and the launch sites,’’ said association President Terry Frazee, adding that his group also kicked in $17,000 to pay inspectors this summer, in partnership with the city of Spicer, Kandiyohi County and the Middle Fork Crow River Watershed District.

Inspectors are stationed at all six Green Lake public boat-access sites. Watercraft found to be contaminated with milfoil or another AIS are directed to the pressure washer at Saulsbury Beach.

“If a boat owner refuses to have his boat cleaned, the sheriff will be called,’’ Frazee said.

Added Schneider: “The first step this summer was to further educate the public about invasive species by having the machine there for people to see. We’re optimistic that if the state continues to be aggressive, we can achieve success here, which we define as no increase anywhere in Minnesota of infested lakes.’’