Herbicides Applied to Atwater Bluff

Shorewood parks have been chemical-free for at least three years – so the sight of herbicide application markers has been a bit jarring for some beach-goers at Atwater Beach.

Although the Village Board decided in 2010 not to use pesticides or herbicides on public lands, the landscaper in charge of restoring the bluff at Atwater Park said  herbicides were the only solution to killing invasive species and stabilizing the bluff.

The village spent nearly $1 million over the summer in 2011 to stabilize the bluff after torrential rains caused severe erosion. An access road for service and emergency vehicles and boardwalk were also built during the work.

Last month, the village contracted Marek Landscaping for new work: a five-year native costal dune/beach, wetland and upland restoration project, aimed at restoring habitat, increasing bio-diversity and improving water quality.

Part of that plan includes select herbicide applications. Marek Landscaping owner Mike Marek said certified pesticide applicators have applied five different types of diluted herbicide mixes to select invasive plants on the bluff.

"We’re only spraying what plants will be a major threat from a displacement standpoint," he said. 

Marek said eliminating invasive plants and replacing them with a wider variety of native plants will lead to deeper root systems, which do a better job of holding the soil together and stabilizing the bluff. Native plant root systems go as deep as 10 to 14 feet in the ground, while invasive plants can only root eight to 12 inches in the ground. Native plants also lead to greater biodiversity.

Marek said the invasive plants are identified by their company's senior ecologist, who determines whether the weeds should be cut, pulled or treated with herbicide. 

"If we can simply cut it, we’ll do that. If it’s a perennial weed – that cutting or pulling it would increase its abundance – that’s when we use selective herbicide, meaning a herbicide that’s designed for that type of weed." 

Marek said he is an advocate for organic lawn care, so he understands concerns about the public health risks of pesticides and herbicides. He said the herbicides at Atwater are absorbed into the ground fairly quickly, so none of the active ingredients will ever reach the infiltration basin at the base of the slope.

"If we had a reasonable alternative to managing these species – if there is one –  we are constantly researching it and using the latest management strategies," Marek said. "We’re all conscious of the harmful effects of herbicides, and we balance those with letting the invasives take over."