Distinguishing Between Delineation Layers & When To Use Them

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There are two categories of groundwater delineation layers included in the Wellhead Protection Viewer: the Tri-County Regional Planning Commission Wellhead Protection Areas (TCRPC WHPA), and the Time of Travel (TOT) Areas. Each of these layers represent slightly different methods of modeling our region’s groundwater systems and it is important to understand the background of their creation when determining which layer will provide you and your community with the most relevant delineations.

The first type of delineation layer, the TCRPC WHPA, was created using the Michigan Groundwater Management Tool (MGMT). This tool, developed by faculty at the Michigan State University Civil and Environmental Engineering Department and staff at Michigan Department of Environmental Quality (now the Department of Environment, Great Lakes, and Energy [EGLE]), analyzed groundwater flow using available well record data for delineating wellhead protection areas, contaminant migration, and groundwater flow direction from the statewide Wellogic database and inputting it into a 2D groundwater modeling software program. Given a few parameters, such as current groundwater levels, hydraulic conductivity of the pumped aquifer, well locations, and pumping rate, the tool was able to demarcate provisional delineations of the public groundwater supply. Providing this data to local communities offered those without the resources to produce delineations themselves a place to start when creating wellhead protection plans or developing other groundwater protection initiatives.

The second type of delineation layer, the TOT Areas, was created using a United States Geologic Survey (USGS) model that utilized MODFLOW-2000 to create a 10-layer, grid-based, 3D model (composed of 3 layers in the glacial package; 6 layers in the Saginaw Formation [of which there are 3 aquifer units and 3 confining units]; and 1 layer to represent the bedrock beneath the Saginaw Formation). The data in these layers covers a select portion of the tri-county region and has undergone various updates over the years. As of August 2020, the TOT data for Michigan State University and Delta Township is from 2007, and the TOT data for Lansing Board of Water and Light and East Lansing Meridian Water Sewer Authority is from 2017.

It is important to note that in almost all cases, the MGMT/TCRPC WHPA layers matched the traditional USGS/TOT layers very closely when compared by an EGLE modeler. However, because of the more in-depth modeling method used to create the USGS/TOT delineations, it is recommended that USGS/TOT layers are used wherever they do exist. Where they are not available, the MGMT/TCRPC WHPA layers should be used to provide a baseline delineation to work from. The photo on the left illustrates the two types of layers, with the TOT layers in orange, yellow, and green transparent shapes; and the WHPA layers in red and blue-dotted shapes.

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Report an Error in the Wellogic Well Records

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Because individual well records are maintained by the state and not Tri-County, we ask that any identified errors in your well records are reported directly to Wellogic. To report an error in the well log on the Viewer's Wellogic layer, please email Wellogic Help at wellogic@michigan.gov with the Well ID and the reason for the change. For more information about the Wellogic system, check out their FAQ page here.

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History of Regional Groundwater Protection & The Wellhead Protection Viewer

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As a region that relies primarily on groundwater for our drinking water supply, wellhead protection plans play a vital role in our communities’ efforts to ensure our water is safe and clean. The Michigan Department of Environment, Great Lakes, and Energy (EGLE) assists local municipalities through their Wellhead Protection Program by helping them to identify and protect areas that contribute to their water supply and prevent or minimize groundwater contamination to avoid costly cleanup efforts. One of the major focuses of these plans are Potential Contaminant Source Inventories (PCSI): a detailed list of locations that pose a high risk of pollution for our groundwater resources, such as leaking storage tanks, oil and gas spills, septic systems, or abandoned wells, just to name a few. By providing a database for these PCSI locations like the Wellhead Protection Viewer, Tri-County and the GMB are able to offer communities access to this information so they may appropriately plan for projects to reduce the risk of groundwater pollution. ​ To assist with funding for a wide range of these wellhead protection projects – including the maintenance of PSCI data, wellhead delineation studies, outreach and education materials, training opportunities, and more – EGLE’s Wellhead Protection Program provides communities with the opportunity to apply for the Source Water Protection Grant each year. The Wellhead Protection Viewer was created thanks to this grant opportunity in 1999 and has continued to utilize its funding for updates in subsequent years. ​ The latest improvements to the Wellhead Protection Viewer were completed in August 2020, funded in part by the Source Water Protection Grant awarded to the East Lansing Meridian Water Sewer Authority. Thanks to an opportunity presented to Tri-County through our consultants at OHM Advisors, the Wellhead Protection Viewer was updated to include data for the entire tri-county region in addition to the originally included communities of Meridian Township and the City of East Lansing.

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