Agenda - Public Works Committee - 09/17/2019

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contaminant sources that must be inventoried in DWSMAs vary according to the aquifer vulnerability classification. For this Plan, the potential contaminant source types inventoried during the PCSI were those required by the MDH for areas in which aquifer vulnerability is classified as Moderate. As shown in Table C-2, information on potential contaminant source locations was obtained from the following sources: Minnesota Department of Health (MDH), Minnesota Department of Natural Resources (MDNR), Minnesota Department of Public Safety (DPS), Minnesota Geological Survey (MGS), Minnesota Office of Pipeline Safety (MnOPS), Minnesota Pollution Control Agency (MPCA), Metropolitan Council, Minnesota Geospatial Information Office (MGIO), Minnesota Department of Transportation (MnDOT), and U.S. Environmental Protection Agency (USEPA) databases. Information from the various sources was compared to identify overlaps/duplications. As part of the PCSI work, all identified potential contaminant source locations within the DWSMAs were verified to the extent possible with available information. As part of location verification, any inaccurate locations identified during the PCSI (i.e., any potential contaminant source entities that appeared to map on the wrong property parcel) were corrected to the extent possible based on available information. For future updates of this Plan, the City will access available data sources and maintain as accurate and up to date a potential contaminant source database as possible in its wellhead protection file. The City maintains current records of the conditions around the municipal water supply wells. Water system operators check the area around each well routinely and report any conditions of concern. A potential contaminant source inventory for the Inner Wellhead Management Zone (IWMZ) around each of the municipal supply wells was completed on June 12, 2019. Copies of the IWMZ inventory reports are presented in Attachment C-1. Properties identified as potential sources of contamination during the PCSI are listed in Table C-3 through Table C-8 as follows: Wells Table C-3 Potential Class V wells Table C-4 Storage tanksand LUST sites Table C-5 Chemical storage sites Table C-6 Spill locations Table C-7 Potential contaminant site Locations Table C-8 Results of this inventory indicate the presence of several potential contaminant source properties within the DWSMAs. Locations of potential contaminant sources are shown on Figures C-5 through C-10 as follows: Well locations Figure C-5 Potential Class V Well locations Figure C-6 Storage tank and LUST sites Figure C-7 Chemical storage sites Figure C-8 Spill locations Figure C-9 Potential contaminant site locations Figure C-10 These potential contaminant sources have been considered in the development of the management strategies for the DWSMA. C-3