WCMA Notes: Water Quality Solutions Begin with Agriculture
Wisconsin Governor Tony Evers declared 2019 the “Year of Clean Drinking Water in Wisconsin,” an opportunity for farmers, industry, municipalities and government to work together to address protection of drinking water for state citizens.
This statewide initiative addresses urban lead contamination and nutrients found in rural wells. On August 1, Gov. Evers announced his focus on the rural side: Wisconsin’s Department of Natural Resources (DNR) will develop new performance standards for farms to control nitrate in areas of the state with highly permeable soils.
Both the Governor and state legislature have taken up clean water initiatives following evidence from studies finding elevated nitrates in some private wells in Wisconsin. For example, Grant, Lafayette and Iowa counties in the southwest corner of Wisconsin found 15 percent of 539 wells tested in April 2019 held nitrate-nitrogen rates above the 10-ppm health standard.
Nitrates in groundwater and phosphorus in surface waters such as lakes and streams are a concern in food-growing states like Wisconsin, and the solution begins in agriculture.
Weeks before proposing new nitrate standards for some farms, Gov. Evers preserved $750,000 annually in Wisconsin’s two-year budget for farmers who engage in best management practices as part of watershed protection groups found throughout the state.
More than two dozen produced-led watershed groups have formed to address nutrient run-off issues in their local areas. The most recent (2018) report from Yahara Pride Farms – 41 farms in Dane County – detailed conservation practices that reduced phosphorus run-off to Madison lakes by 22,097 pounds.
“The producer-led program is a great tool to protect water quality in the state, and is especially important in this Year of Clean Drinking Water,” Gov. Evers said in July. “It’s been very successful in creating new, local efforts, with neighbors helping neighbors find ways to protect our surface and groundwater.”
Dairy processors in Wisconsin have spent the last decade adopting technology and partnering with Wisconsin DNR to successfully implement some of the strictest water quality criteria in the nation.
Dairy plants across Wisconsin have responded to tightened standards for phosphorus implemented by Wisconsin’s DNR in 2011. Technology is advancing to achieve ultra-low water quality limits for phosphorus in treated water released to streams and lakes – as low as 0.075 mg/l for industries including dairy manufacturers.
Technologies including sand filtration and high-tech membranes added to aerobic and anaerobic treatment of wastewater are achieving nutrient reduction. Alternatives such as phosphorus trading developed by Wisconsin DNR and Wisconsin’s EPA-approved multi-discharger variance are helping municipalities and industries alike. The variance allows water treatment facilities to stairstep phosphorus levels downward while funding countywide efforts to reduce phosphorus run-off from farms.
In August, more than 50 wastewater specialists and technology suppliers in the dairy industry toured a state-of-the-art wastewater processing plant serving AMPI’s cheese factory in Jim Falls, WI. The recently commissioned system uses state-of-the-art filtration to achieve regulatory quality standards, preparing water for discharge to the local river. AMPI, like other manufacturers, can also dewater the solids that emerge from wastewater treatment, resulting in a mineral-rich “cake” that has potential for use as fertilizer or a soil conditioner.
Many smaller cheesemakers in Wisconsin treat wastewater and discharge to land-based systems that use soil microbes to breakdown nutrients. Similar to farm fields, nitrogen is the key water quality limit for these land-based systems.
In 2015, WCMA joined with Wisconsin DNR and Midwest Food Processors Association Wisconsin to examine the fate of nitrogen in spray fields and terraced systems commonly called “ridge & furrow” systems. University of Wisconsin Soil Science professor Francisco Arriaga and his team performed on-site studies of three ridge & furrow systems and three spray fields around Wisconsin, capturing data on nitrogen after fresh applications of treated wastewater.
The final report, released this summer, notes that soil-based wastewater treatment systems “appear to provide an effective means to treat nitrogen,” with management, composition of wastewater and weather as factors affecting performance.
Everyone wants clean drinking water. The solution lies in government, cities and towns, industry and agriculture teaming up to find solutions in science, technology and best practices to keep excess nutrients from the water we need.