There are several reasons you may be testing the ammonia (NH3) or nitrate (NO3) in a septic system.1. Direct discharging system - If you have a system that directly discharges to a lake, river or stream you may have an ammonia limit. NH3 can be toxic to freshwater organisms at concentrations ranging from 0.53 to 22.8 mg/L. Toxic levels are both pH and temperature dependent. Toxicity increases as pH decreases and as temperature decreases.2. Denitrification system - Wastewater naturally contains fairly high levels of total nitrogen, typically in the range of 50-90 mg/L. It is found in four different forms:
