The Minnesota Department of Natural Resources will collect water samples from about 180 wells in Otter Tail County for use in developing the county’s Groundwater Atlas.
Selected well owners will be contacted by mail or phone to request permission to sample their wells. The process involves collecting a water sample from an outside spigot or hydrant for laboratory analysis. Dozens of different water components are analyzed to determine the natural chemistry of aquifers. Participation is voluntary and owners will receive a report of the laboratory results.
Wells are selected based on geology, location, well depth and well construction. Well owners’ participation will help hydrologists create county maps and descriptions of groundwater distribution, movement, and conditions, and the pollution sensitivity of aquifers. The final atlas products will be available as printed maps, reports, and geographic information system files available online. Sample well locations are shown on the maps, but no contact or ownership information is included in the data.
The groundwater atlases are used to identify viable sources of drinking water, manage aquifers sustainably, guide decisions for well and septic system construction, inform well-head protection efforts for public water supply, understand regional recharge and groundwater movement, and assess pollution sensitivity and possible contaminant migration.
The Groundwater Atlas of Otter Tail County will include two parts. Part A, the geology of Otter Tail County, will be completed by the Minnesota Geological Survey later in 2023. Part B, which the DNR expects to complete in 2025, will cover groundwater in the county, including the results of this well sampling effort.
The County Atlas Program is funded in part by the Minnesota Environment and Natural Resources Trust Fund as recommended by the Legislative-Citizen Commission on Minnesota Resources.
A full description of this DNR program and completed atlas products are available on the DNR website.