Nitrogen runoff is a significant facilitator of algal blooms.
Additionally, nitrogen provides a nutrient-rich environment for toxic bacteria to prosper, such as cyanobacteria blooms. In the past, cyanobacteria blooms were thought to be caused solely by phosphorous, thus could be treated with aluminum sulfate. However, aluminum sulfate cannot be used to treat nitrogen. As a result, nitrogen runoff and the leaching of old septic systems must be contained to protect source water from cyanotoxins.
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