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October 2015 MLGW-ACR GW Quality Memo♦3 <br /> 2.0 MLGW-ACR WELL EVALUATION <br /> Henderson conducted an evaluation of MLGW-ACR to further analyze possible sources of <br /> elevated dissolved iron and manganese concentrations in water quality samples. The objective <br /> of the well inspection was to investigate whether local well conditions, such as the possible <br /> effect of iron and/or manganese-related bacteria in the well casing, could be causing the <br /> elevated dissolved iron and manganese concentrations. The well evaluation included three <br /> tasks: 1) a visual inspection of the well casing,2) bacteriological reactivity testing,and 3)water <br /> chemistry and biological testing. <br /> 2.1 WELL INSPECTION <br /> MLGW-ACR is a 6.5-inch diameter,60 feet deep supply well that was constructed in 1988. It <br /> is constructed of mild steel casing,which is pitted as shown in the photographs below. The <br /> pitting in the steel casing is an indicator of casing corrosion. <br /> ►� s ��� EMI <br /> This well has been sampled triannually since 2012 per the GWMP. During sampling events <br /> purge water is typically turbid with a great deal of suspended solids and iron-oxide sediment <br /> (Aquionix personnel communications,2014). <br /> 2.2 BART TESTING <br /> On August 6, 2014, biological activity reaction test (BART") samples were collected from <br /> MLGW-ACR by Aquionix to assess bacterialogical activity in the well. BART'`•" samples are <br /> a simple and effective method for qualitatively monitoring the activity of specific groups of <br />