Agenda - Council - 10/08/2019 - Laserfiche WebLink

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C1.0 Data Elements Assessment The data elements and their assessments required to be included in the Wellhead and Source Water Protection Plan amendment (WHPP) for the City of Ramsey (Public Water Supply 1020035) are discussed in this appendix. Data elements related to the physical environment, land use, water quantity, and water quality required for this WHPP for the City of Ramsey were specified in the April 4, 2019 Scoping 2 Decision Notice from the Minnesota Department of Health (MDH, 2019). The City of Ramsey (City) currently operates eight municipal water supply wells (Table C-1 ). All eight wells are completed in the Tunnel City-Wonewoc aquifer. Two Drinking Water Supply Management Areas (DWSMAs) have been delineated for Ramsey (MDH, 2018). The DWSMAs encompasses the Wellhead Protection Areas (WH PAs) for the Ramsey water supply wells. The West DWSMA is entirely within the Ramsey city limits. The East DWSMA extends beyond the city limits into the city of Anoka. The locations of the Ramsey DWSMAs are shown on Figure C-1. C1.1 Physical Data Elements Physical data elements required to be considered for this Plan amendment are identified in the Scoping 2 Decision Notice (MDH, 2019). Per the Scoping 2 Decision Notice, geology and water resources data elements were required to be considered during development of the Plan amendment. C1.1.1 Geology and Hydrogeology Existing information on the geology and hydrogeology in the vicinity of Ramsey was used to define the extent of the source water aquifer used by the City, delineate the WH PA, and to assess the vulnerability of the public water supply wells and the aquifer in the DWSMA. As indicated on Figure C-2, the uppermost bedrock unit in the vicinity of the Ramsey DWSMAs varies with location and includes the following Cambrian -age units: Jordan Sandstone, St. Lawrence Formation, and Tunnel City Group (Mossier, 2011). Depth to bedrock beneath the Ramsey DWSMAs ranges from approximately 110 feet to approximately 210 feet. One fault has been mapped (see Mossier, 2011) that intersects the eastern edge of the East DWSMA. Quaternary -age unconsolidated sediments overlie the bedrock in the vicinity of Ramsey (Meyer, 2011). Most of these sediments in the vicinity of Ramsey are terrace deposits from the ancestral Mississippi River. Small, discontinuous areas are covered with peat and muck deposits. WeII construction information for the Ramsey municipal wells is summarized in Table C-1 and copies of the MDH well records are presented in Appendix A. Information regarding the geology and hydrogeology of the area was used to assess the vulnerability to contamination of the source water aquifer within the DWSMA (see MDH, 2018). The information is consistent with the classification of the susceptibility to contamination of the source water aquifer within the DWSMAs as Moderate. C-1