Nitrates are one of the harmful contaminants derived from human wastewater. They are created by microbes in the septic field. In a properly draining septic system, the nitrogen in nitrates will be taken up by plants, or de-nitrified by other microbes, thereby converting nitrates to harmless molecules. If the septic system has been overloaded, nitrates can accumulate and move into the aquifer without having been treated by natural processes.
In Canada, the safe limit set for nitrates in drinking water is 10mg/L. In 2017, the nitrates reading from SSID's well-1 jumped to 5.14, which was still only half the Maximum Allowable Concentration, but was enough to cause concern about possible further increases. To monitor the situation, SSID's Water Sampler started taking nitrates tests monthly. After the nitrates levels had decreased for a couple of years, we began testing quarterly instead. The Nitrates Tables below are also available for download as PDFs from the bottom of this webpage. Related documents may be found on the Maintain Your Septic System webpage.