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Total organic carbon (TOC) is an key surface water treatment parameter because it can impact <br /> treatment processes, taste and odor, and disinfection byproducts. TOC measurement at the Anoka site <br /> has not had the frequency of sampling as at the intakes of the St. Cloud and Minneapolis WTPs. Table <br /> 2-2 and Figure 2-2 summarize the TOC along the Mississippi River, indicating the number of samples <br /> and range of dates characterizing the summary statistics. This set of data indicates the average TOC <br /> concentrations at the three sites are very similar, from 9.2 to 9.4 mg/L, and can range from 5 to 18 <br /> mg/L. <br /> Table 2-2.Total Organic Carbon Summary at Multiple Sites <br /> St. Cloud - MDH Anoka - MCES Fridley - MDH <br /> Avg, mg/L 9.20 9.37 9.41 <br /> St Dev 2.3 2.3 2.51 <br /> Min, mg/L 5.6 5.1 5.6 <br /> Max, mg/L 18 14.5 18 <br /> Num. Samples 122 20 115 <br /> 95t" Percentile 13.9 NA 14.0 <br /> Sample Start Date 1/6/2010 4/29/1996 1/5/2010 <br /> Sample End Date 11/4/2019 4/15/2019 11/5/2019 <br /> Figure 2-2.Average Total Organic Carbon at Multiple Sites <br /> 14 <br /> Error bars are+/- 1 St. Dev. <br /> 12 <br /> bn T <br /> 10 <br /> 0 <br /> g <br /> U <br /> V_ <br /> n3 <br /> 6 <br /> aA <br /> O 4 <br /> c� <br /> H <br /> 2 <br /> aA <br /> Q 0 <br /> St. Cloud - MDH Anoka - MCES Fridley-MDH <br /> 2.1 c Drinking Water Regulated Constituents <br /> None of the constituents measured in the Mississippi River at Anoka, except those treated by <br /> conventional treatment for solids and pathogens, exceed the Safe Drinking Water Act (SDWA) <br /> Maximum Contaminant Level (MCL). MCES also analyzed the Mississippi River for other constituents <br /> as part of their priority pollutant monitoring requirements. There were no organic compounds or metals <br /> (not already reported for the SDWA list) present at levels that exceed the SDWA MCLs. Appendix A <br /> provides the summary statistics for the complete set of constituents analyzed at each of the MCES and <br /> MDH monitoring stations. <br /> The US EPA maintains a Contaminant Candidate List (CCL) for contaminants that may need to be <br /> regulated, which is published every five years. The current CCL includes 97 chemicals or chemical <br /> Page—9 1 METROPOLITAN COUNCIL <br />