Why is nitrogen a constituent of concern?
The final constituent of nitrogen reaching the groundwater from on site wastewater disposal systems is nitrate nitrogen. This dissolved form of nitrogen moves readily through the soil with only diffusion providing mitigation of its concentration. In estuarine environments, nitrate is a fertilizer. Excess concentrations of nitrate nitrogen will cause algae blooms, which lead to rapid eutrophication of estuarine systems such as salt-water ponds, harbors and estuaries. Critical concentrations of nitrate nitrogen in certain coastal ponds in Falmouth were determined to be at 0.32 milligrams per liter (mg/l) or PPM (parts per million) in the salt water. The nitrogen loading for each marine system is different based on the particular flushing, shape and depth of the coastal embayment. In general, nitrogen concentrations in ground were draining into marine embayments on only has to be a fraction of the concentration of nitrate nitrogen to be a problem in the receiving salt waters compared to t
