Discovery Farms Co-Directors Respond to Karst, Recommend Next Steps For Agriculture to Take

By Jane Fyksen, Crops Editor
Thursday, January 24, 2008 12:26 PM CST

The UW Discovery Farms formally responded last week to the Dairy Business Association regarding the controversial Karst Task Force Report. DBA has major concerns about the Karst Report which, though focused on Northeast Wisconsin, has potentially far-reaching implications statewide for siting of livestock farms and manure management.

Northeastern Wisconsin has grappled with groundwater quality problems and well contamination for many years. Public attention in the region is riveted on manure. UW-Extension and county conservationists in Brown, Calumet, Door, Kewaunee and Manitowoc counties formed a task force to examine existing scientific data regarding the area’s problematic Karst features (sink holes and bedrock openings) and shallow carbonate bedrock. Last year, this Northeast Wisconsin Karst Task Force issued its report, which included controversial recommendations on how to address groundwater vulnerability n solely targeting farmers and manure management.

The Karst Report caught the attention of local units of government, possibly looking to adopt more stringent land-use regulations. The concern of some in Wisconsin agriculture (including DBA) is that this task force’s analysis and recommendations will be held up by local units of government as evidence that, indeed, they might impose more stringent standards than what Wisconsin’s new siting standards require. The Karst Report and its manure recommendations are garnering attention statewide, well outside of northeast Wisconsin where well water degradation and manure runoff incidents have recently drawn public attention.

DBA asked UW Discovery Farms to review and comment on the nutrient management provisions of the Karst Report. Discovery Farms Co-Directors Dennis Frame and Fred Madison last week did so, concluding that “while the report contains some valuable recommendations, its assessment of the vulnerability of the unlithified materials in the area appears overstated.”

“It does seem that once a better understanding of the distribution and thickness of those unlithified materials is development and maps are produced at appropriate scales, wastes can be applied to those landscapes with little or not impact on the fragile groundwater system in the carbonate bedrock aquifer,” the Discovery Farms leaders told DBA.

Why should Discovery Farms be called on to comment on this report? The program was initiated nearly six years ago as a cooperative effort between working farmers and the UW. Its goal has been to examine environmental challenges faced by Wisconsin producers and develop solutions that make both economic and environmental sense. Because the program works in a real-world setting, data generated is rare, very difficult to collect and of great interest to scientists, policy-makers, farmers and other ag stakeholders and state and federal agencies.

Frame and Madison summarized four goals the task force was charged to examine as: Determine where its impact on the Karst aquifer begins; evaluate best methods to reduce agriculture’s impact on groundwater quality; prioritize implementation of available technologies to prevent future problems; and determine gaps in knowledge.

Frame and Madison also highlighted five guiding assumptions made by the task force and paraphrased them as follows:

- “Prevention of all surface contamination of groundwater is a physical impossibility; however, there are actions that landowners can take to reduce potential contaminations from livestock manure, human waste and other contaminants.”

- “There is a serious need for better mapping of Karst features.

- “The recommendations are based on scientific knowledge and professional judgment.”

- The recommendations are focused primarily on agricultural issues (in fact, almost entirely on manure). While the other issues (septage, industrial waste, on-site sewage treatment, etc.) could be a significant part of the contamination program, they are beyond the scope of this task force.”

- “A uniform approach that provides a stable framework for environmental protection is needed.”

Frame and Madison, in a letter to DBA Executive Director Laurie Fischer, said that the “merits” of the task force’s goals and guiding assumptions could be debated, but neither thinks that’s a “productive use” of time and effort. Instead, the UW-Discovery Farms co-directors said they’re “eager” to work with DBA and Wisconsin agriculture “on the development of a strategy that is necessary, reasonable and implementable on Wisconsin farms with Karst features.”

They also noted that it’s maybe not a good assumption for the task force to propose its recommendations apply only to a limited number of counties in the northeastern part of the state. Carbonate bedrock with associated sinkholes and fractured rock overlain by shallow soils occurs in many areas of the state, and some of those localities are already looking to the Karst Report for ideas and directions to deal with potential groundwater contamination, according to Frame and Madison.

The UW Discovery Farms leadership recommended that additional financial resources be allocated for on-farm research in three areas of the state (northwest, southwest and west central) to identify acceptable application rates, methods and timing for not solely manure but also septage (from septic tanks) and other sources of nutrients.

Expanding on recommendations made by the Karst Task Force, Frame and Madison suggested that a mapping program that identifies the thicknesses and distribution of soils and unlithified materials at scales appropriate for ag producer be developed. They recommend a pilot project by the Wisconsin Geological and natural History Survey in Calumet County to determine the time and cost of such a mapping program. That goal, they said, would be to develop high quality soil thickness maps, identify sources and amounts of manure, septage and industrial wastes applied on a county or township basis and develop recommendations of when, where and how those nutrients should be applied in Calumet County in order to reduce the risk of contamination of surface and groundwater. Funding would be needed for this to happen.

Discovery Farms said the “most significant” recommendations contained in the Karst Report detail levels of required protection based on landscape criteria and relative vulnerability to contamination. Those are:

- Level 1 n Less than 5 feet (60 inches to carbonate bedrock, and/or closed depressions or any drainage areas that contribute water to sinkholes/bedrock openings) n “Extreme” vulnerability

- Level 2 - 5 to 15 feet to carbonate bedrock n “High” vulnerability

- Level 3 n Over 15 to 50 feet to carbonate bedrock n “Significant” vulnerability

- Level 4 n Greater than 50 feet to carbonate bedrock n “Moderate” vulnerability.

Frame and Madison agree that when carbonate bedrock is near the surface (less than 5 feet), the ability of the soil to adequately treat either livestock or human waste decreases dramatically as the soil layer gets thinner (Level 1). Where there’s 5 to 15 feet of soil and unlithified material overlying carbonate rock, there is still a potential for movement of contaminants through fractures, particularly in the unlithified materials, they reported.

However, the Discovery Farms heads told DBA that it’s their opinion that the Karst report “overstates the risk on medium and fine textured materials that are between 15 and 50 feet thick (Level 3).” Research currently underway suggests initially that movement of water through these materials is “extremely limited,” they noted.

“Therefore, the potential for water movement through medium and fine textured materials greater than 50 feet thick (Level 4) is probably non-existent,” they stated.

Frame and Madison also told DBA that a “particularly complex issue” arising from the Karst Report recommendations “is the question of liability.” They said it’s going to be difficult to define and/or assign liability if a spill or runoff event occurs resulting in groundwater contamination or other environmental problems. Hence, they recommend that a committee of attorneys (both private and state agency) review the issue of liability and “develop a strategy that limits this liability for producers, consultants and manure applicators who have implemented acceptable strategies that should reduce losses to ground or surface waters.”

They note that that people who need to be involved working with producers and agency personnel to solve the problems associated with farming in carbonate bedrock areas of the state are going to be “reluctant to get involved” unless unanswered liability issues are clarified.

The Karst Task Force also made recommendations regarding well construction, maintenance and testing. The Discovery Farms co-directors said those are “sound ideas” basically involving educating homeowners about their wells. They suggest a similar program to one developed by Extension in Pennsylvania be established here in Wisconsin. That “Master Well Owners Program” is based on the familiar “Master Gardeners Program.” UW-Extension would have a role in delivering the education and training portions of this program.

Lastly, the Task Force Report also makes recommendations regarding the uniformity of codes covering land application of numerous waste materials. Different agencies may control application of different materials to the same piece of ground. “As complicated as it may be, these differences should be ironed out so that landowners hear a uniform message regardless of the type of waste,” stated Frame and Madison.

Frame and Madison find fault with the Karst Report in that is deals primarily with livestock manure and doesn’t provide recommendations to protect groundwater from other sources of nitrates as well.

The report also provides recommendations requiring manure injection but “fails to identify UV radiation and drying as methods which significantly reduce pathogen concentrations,” they noted. Three years of data from seven sites on Discovery Farms indicate that 93 percent of annual runoff occurs between January and June 1, while the remainder occurred in early June. This means that surface manure applications could be made from late June n January (depending on weather forecasts) with little risk of runoff or infiltration. Frame and Madison suggested producers need to think about manure management as a year-round practice and look for windows of opportunity to safely apply manure.

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