Local government strategies to protect groundwater
Groundwater can, and in some places has, become contaminated. Local government is best-suited to prevent contamination from occurring but seldom uses these 11 zoning tools at their disposal to do so.
January 25, 2016 - Author: Kurt Schindler, Michigan State University Extension
Protecting groundwater supplies is often unaddressed until it is too late. Keep your community running smoothly with clean safe supply of water by some common sense practices in your master plan, zoning ordinance, and other community practices:
- Develop a wellhead protection plan if your community has type I public water wells/public water system. Wellhead Protection Program is designed for public water supplies. With Wellhead Protection, communities conduct a detailed study about its water wells including the area from where the well pulls its groundwater. To do this, hydrologists trace the route of the water backward for ten years and draws a map showing the land surface corresponding to the area above ground where the water originated. This map delineates the critical land area where actions on the surface which can result in contamination getting into the ground and eventually make their way into the public water supply. The community writes a Wellhead Protection Plan for each municipal well or well system. The plan includes a historical inventory of what land uses occurred in the past that might have contributed contamination so the community can be proactive about looking for that contamination. The plan also inventories current land uses and finally the plan describes steps they will take to avoid contamination sources in that area in the future.
- Use an overlay zone for even more protection around municipal water wells (type I water wells). This will protect the water that would be pumped into a public water well during the ten-year, five-year, and one-year time of travel. More on this is found in the Land Use Series “Sample Zoning Amendments and Program For Groundwater Protection.” Zoning should prohibit certain land uses (known as high-risk contamination sources) within the overlay district. It should also include site plan review standards that include secondary containment design where hazardous substances are stored, handled, or used. “Secondary containment” is a design that recognizes accidents such as spills happen, but the space is designed so any spill is contained and does not soak into the ground. That means no drains, swales, ditches, or other systems that discharge onto the ground.
- Draft and include zoning amendments for general groundwater protection. The Land Use Series flyer. Includes sample language for zoning ordinances. For example, “wall-to-wall” protection that requires site plan review with secondary containment standards to protect not only municipal water wells but also private water wells, surface water, and wetlands.
- In addition there needs to be provisions in zoning concerning surface water (including wetland) protection. The article Local government has an important role for water quality protection talks about this local government role. Part two presents a perspective retaining important habitat on lake’s and river’s edge and part three discuss the legal aspects. There is also a guidebook which suggests planning and zoning essentials to protecting water quality. That book includes six essential elements in master plans and zoning ordinances can help protect Michigan’s water quality. New water quality protection guidebook can help rural communities understand and include those provisions in their plans and regulations.
- Finally, adopt police power ordinances, and other programs to avoid contamination such as fire chief inspections, incentives, and education campaigns.
Why might you want to bring these practices to your community? Three practical reasons: drinking water supplies, businesses, and ecosystem dependence. Also hunting, fishing, tourism and aesthetic benefits flow from unpolluted fresh water.
In Michigan groundwater is the source for 1,132 community water systems. In addition, 29.5 percent of households, 2.6 million people, rely on private water wells, groundwater, for their water supply. In addition groundwater is the major source (70 percent) for agricultural irrigation on 5,078 farms (2007 Census of Agriculture). Groundwater is also critical to many ecosystems in Michigan – providing a steady flow of cool high-quality water to streams, lakes, and wetlands.
Despite the widespread dependence, little is found in local zoning to protect or prevent contamination of groundwater.
How do these protections work? They address the basic problem: the groundwater we use is vulnerable to contamination from what is put on the surface of the ground. Glacial deposits (soils from the top of bedrock to the surface) are largely permeable. “Permeable” means liquid and contaminants can and does soak through the soil from the surface to groundwater. Most groundwater wells are pulling water from the glacial deposits (68 percent). The remaining 32 percent pull water from within bedrock. But a significant amount of the bedrock found in Michigan is also permeable -- Karst bedrock particularly so.
There is a prevalent myth that groundwater is protected if there is a clay soil layer between the surface and water. While clay is a good barrier, it is not a failsafe. It too is permeable. The rate of movement of water and contaminants through clay is much slower. But many clay layers are not continuous. Clay layers have holes, cracks and breaks allowing leakage. Therefore, when there is a spill on the surface it is not a question if surface contamination will reach groundwater, but only how long it will take.
With permeability surface water (lakes and rivers), wetlands, and groundwater are often inter-connected. Contaminants in one can move to the others. Thus a protection program really needs to focus on all three: surface, wetland, and groundwater. Local zoning is one of the most effective tools to do this in a way that is preventative. Zoning can often avoid problems from occurring in the first place.
Many think Michigan, the Great Lakes State, has limitless abundant fresh water. But problems with groundwater has occurred in this state at many locations. Sometimes the issue is much more widespread than isolated locations. In Ottawa County groundwater has become impaired with wells pulling up salty water. There they have also observed a problem with the overall lowering of groundwater levels throughout the county. See the article Ottawa County groundwater has quality and quantity concerns.
Not putting in safeguards could come at a high cost since groundwater is always at risk, and cleanup is very expensive, it is advised that communities take precautions with the tools available to them.
Those in Michigan State University Extension that focus on land use provide various training programs on planning and zoning, which are available to be presented in your county. Contact your local land use educator for more information.