3.4. SR 08-25-1997 - Laserfiche WebLink

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PCBs Manganese TCDD eq~uivalencs (dioxin or furans) Mercury Toxaphene Nickel Zinc Both lists include semivolatile organi.'c compounds and metals. It is likely that pollutants that are deposited from the atmosphere to the C-teat Lakes, and in particular to Lake · Superior, will also be deposited to inland lakes and their surrounding terrestrial ' watersheds. One could then consider the Great Waters and Lake Superior Binational Program'~pollutants of'conc~zn" to also be of concert in Minnesota. A comprehensive monitoring effort would help identify the chemicals of concern in specific areas of the state. What are "background" concentrations of these ~chemicals of concern" in the environment? Background concentration data in Minnesota is primarily available for mercury in fish and sediment, with some dam available for mercury concentrations in other parts of aquatic ecosystems and soil (Moyle 1972; Helwig and Hcqskary 19T2; Swain and Helwig - 1989; Sorenson eL al. I990; Nater and Cn'igal 1992; Sw~irt et. al. 1992). Ther~ is limited data for other metals in soil (Pierce et. al. 1982; MPCA 198o'). Additional sediment data is being collected on a statewide basis through a Legislative Commi~ion on Minnesota Resources (LCMR) Mercury Study being coordinaled by the MPCA. This LCM1R. study builds upon previous sediment core data collected in northe~ Nflnnesota (Swain et. al. 1992). Other than the statewide data being collected in'the LCMK Mercury Study, most data for metals is limited to specific areas and may not be readily applicable to other areas of the state. An'important piece of information that is often missing and is critical for determining background concentzations is the deposition of the various pollutants to selected locations in the state. Mercury in precipitation monitoring has been ongoing in the stae since 2990 (Sorenson et. al. 1994). However, there is llmlt~l da~ on the concentration of other metals in precipitationin Minnesota. A ~de monitoring study could potentially provide information on pollutant deposition in vaxious parts of the state to estimate background concentrations. 3. Are pesticides ofconcem in 1Minnesota'S environment? Due to intensive agricultural prances, pesticide use in MinneSOta iS common. The ]isis of ch'emicais of concern for the Great Waters and Lake Superior indicates that pesticide contamination is occurring izi theSe large water bodies. The potential impacts of pesticide contamination in smaller water bodies may need further attention in Minnesota and other states. A pesticide component in the statewide toxics monitoring study would provide information on the amounts of specific pesticides being deposited in various locations in the state.