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Caption: This chart shows the minimum, mean, and maximum pH levels measured during the Maine Department of Environmental Protection WQM Program's 2000-2002 stormflow study. Samples were taken during high flow events (after major rainfall events of 1.0 inch of rain or more, or during significant melt events). Mean pH in Sheepscot streams generally ranged from 6.5 to around 7.0; however, pH levels dropped below 6.3 in the mainstem Sheepscot and in Wingood and Choate brooks and increased above 8.0 in the mainstem Sheepscot and West Branch. Kroglund and Staurnes (1999) concluded that low pH levels (< 6.2-6.3) compounded with inorganic aluminum concentration as low as 15-20 µg/L will impair Atlantic salmon smolts. See Info Links for more information.
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