Programs in state and local government agencies are responsible for protecting groundwater from contamination so that drinking water supplies from water are safe for human consumption. The Minnesota Department of Health (MDH) has many roles in this effort including protecting water, ensuring that drinking water from wells is tested and is safe, and recommending cleanup of contaminated sites. Other state agencies also have diverse and important roles in ensuring that the drinking water from wells is safe for human consumption.
MDH Groundwater-Related Programs
Health Risk Assessment
The Health Risk Assessment Unit (HRA) evaluates the health risks from contaminants found in groundwater. These evaluations may be in the form of consultations with other agencies, but the largest effort is in developing Health Risk Limits for groundwater. These are concentrations of contaminants in water that the MDH believes pose little or no risk to public health. The Health Risk Limits are promulgated into rule and used by other agencies for various regulatory and advisory programs. For more, see the Groundwater Values Table and Health Risk Limits for Groundwater Rules.
Drinking Water Protection
Many public water systems in Minnesota are supplied by groundwater. The MDH’s Drinking Water Protection Section ensures that the state’s public water systems meet federal and state guidelines for safe drinking water. Section staff monitor drinking water quality, perform on-site inspections of public water systems, and review plans for water system construction. For more information, see Drinking Water Protection.
Additionally, the Source Water Protection Unit in the Drinking Water Protection Section focuses on the protection of public drinking water sources, including groundwater wells. The Unit has created a Source Water Assessment for each of the state's public water systems, which describes the water sources used and their susceptibility to contamination. The Unit also helps public water systems in developing their Wellhead Protection Plans, which include strategies to prevent the pollution of the groundwater. For more information, see Source Water Protection.
The Well Management Section is responsible for regulating wells and borings to protect both public health and the state’s groundwater. The Section licenses well and boring contractors, registers drilling machines, and administers rules covering the construction, testing, repair, and ultimate sealing of wells and borings. The Section also administers a state law that requires well disclosure at property transfer, maintains state records on wells, and provides public information and brochures on a variety of well and well water concerns. For more information, see Well Management.
Site Assessment and Consultation
The Site Assessment and Consultation Unit (SAC) of the Minnesota Department of Health evaluates sites where there have been uncontrolled releases of hazardous chemicals and there is a potential for human exposures. These sites include state and federal Superfund sites, landfills, dumps, defense sites, industrial facilities, and voluntary cleanup sites. SAC must determine what chemicals are present and in what quantities; whether exposure is likely and the magnitude of likely exposures; and, finally, whether those exposures may pose risk to human health.
Health Risk Limits (HRLs) are one of the tools that SAC uses to make these evaluations. Because SAC works with actual sites and often known, potentially exposed populations, SAC functions as a risk manager. As such, it must determine whether the HRLs should be strictly applied or whether a more or less stringent value would be more appropriate given the unique characteristics of the site. Once a value is identified, if risk is determined, the goal is cleanup. For more information, see Hazardous Chemicals in the Environment.
The Drinking Water Contaminants of Emerging Concern program assesses chemicals for which health-based guidance values either do not exist or need to be updated to reflect new toxicity information, and that could result in a new or emerging concern for existing or potential contamination of drinking water. These chemicals may currently be present in Minnesota groundwater, or may be found in other media (such as surface water or soil). Staff evaluate these chemicals and develop health-based guidance values when there are sufficient toxicological data. For more information, see the Drinking Water Contaminants of Emerging Concern (CEC) program.
Minnesota Department of Agriculture
The Department of Agriculture (MDA) monitors both surface water and groundwater for pesticides, fertilizers, and pesticide residues. The primary purpose of the MDA water quality monitoring program is to define the long term impacts of routine pesticide use on water quality. The goal is to provide information so that pesticide use may be managed to prevent or minimize degradation of the state's water resources.
Groundwater samples are collected from carefully selected sites in twelve counties in the central sand plain region of the state, which is the most area most vulnerable to agricultural impacts. Surface water samples are collected at ten automated monitoring stations. Staff analyze land use, use of fertilizers and pesticides, and hydrologic attributes that may result in degradation of water resources. Additional monitoring sites are planned. For more information, see Monitoring and Assessment for Agricultural Chemicals in the Environment.
Minnesota Department of Natural Resources
The Minnesota Department of Natural Resources (DNR) manages water resources, including groundwater, through a variety of programs with emphasis on water quantity. Groundwater levels in aquifers that are the primary source of water supply are monitored monthly as part of the Ground Water Level Monitoring Program. The Ground Water Mapping Program gathers information about the presence, direction of flow, and natural quality of ground water and about regional geology. Information is used to determine the sensitivity of areas to pollution. Data, analyses of data, and maps constructed from data are shared with all levels of government to assist in ecosystem-based management.
Other DNR water programs collect, maintain, and disseminate information on lakes and streams; gather, manage, archive, and disseminate information on climate; and evaluate water use and impacts in order to make determinations about issuing water appropriation permits and plan for conservation. For more information, see DNR's Division of Waters.
Minnesota Pollution Control Agency
The Minnesota Pollution Control Agency's (MPCA) Groundwater Monitoring and Assessment Program (GWMAP) began in 1989. The program's primary objective was to meet state and local ground water information needs by collecting data on background concentrations of chemicals in ground water and the impact of human activities on ground water quality. The MPCA conducted a statewide baseline assessment of water quality in Minnesota's principal aquifers; conducted ground water trend studies, including land use studies; and shared information with local groups to develop regional cooperatives. Between 1989 and 2001, the MPCA conducted ambient monitoring through this program. In 2003, the MPCA re-established an ambient monitoring effort. For more information, see the MPCA's EDA: Groundwater Programs.
US Geological Survey
The USGS is the leading Federal agency in Minnesota that collects and interprets water-resource data and information used by resource managers, planners, and the general public. To define the availability of water for public, irrigation, and industrial supplies, the USGS monitors stream flow, lake levels, and groundwater levels at many locations and has studied numerous aquifers in Minnesota. Typically, the studies describe the effects of present and future groundwater withdrawals on the levels and quality of groundwater and streams. The results of USGS water quality studies provide water managers with essential information needed to make groundwater management decisions throughout Minnesota. For more information, see US Geological Survey.