What is Nitrate-Nitrogen?Nitrate (NO3) plus nitrite (NO2) as nitrogen. In lakes, most nitrate/nitrogen is in NO3 form. It is measured in milligrams per liter (mg/L). Elevated levels of nitrates/nitrogen are often caused by over application of fertilizers that leach into waterbodies. Total Kjeldahl Nitrogen (TKN) The sum of organic nitrogen and ammonia in a water body. Measured in milligrams per liter (mg/L). High measurements of TKN typically results from sewage and manure discharges to water bodies. More info » |