Lake Pocotopaug Lake and Watershed Restoration Evaluation ...

Dissolved iron concentrations at the water-sediment interface in Lake Pocotopaug wasmeasured in August 2001. Values were low, below the 0.01 mg/L detection limit at both stationsand all water depths (Table 10). These low values in the summer suggest a low phosphorusbinding capacity in Lake Pocotopaug.Total and dissolved aluminum were analyzed in 2001 prior to the alum treatment. Totalaluminum ranged from 0.036 to 0.794 mg/L. Dissolved aluminum was below the detection limit.Aluminum is not list on the State of Connecticut Water Quality Standard Numerical Criteria, butthese values are consider relatively low. In addition, arsenic, cadmium, chromium, copper,nickel, lead, and zinc were analyzed in May 2001. All values were low (Table 10) and suggestno water column metal contamination in Lake Pocotopaug.6.2 Tributary and Storm Drain Water Quality2001 water quality data for tributaries and storm drains are presented for both dry and wetweather in Table 12. Data collected in March of 2001 by the CT DHS are included in thissummary. Locations of the incoming water stations are given in Figure 6 and Table 9.Generally, stormwater sampling resulted in higher concentrations with the exception of pH,chloride, hardness, conductivity and nitrate. This may indicate that there are constant sources,which are being diluted during precipitation, and/or precipitation itself (acid rain) is loweringthese values.Lake Pocotopaug Restoration Evaluation 39May 2002