Nitrogen
Inorganic nitrogen occurs in water as nitrate and nitrite. It can also measured as Total Kjeldahl nitrogen (TKN, after the 19th century Danish Chemist Johan Kjeldahl). This is the sum of ammonia and organic nitrogen found in the water. Typically, nitrogen enters surface waters from farming and agricultural practices and faulty sewer systems. It is also washed off lawns and gardens (which may be over fertilized) during storm events.
Nitrogen is a concern in the Potash Brook watershed, in that it (along with phosphorus) fuels algal blooms in Lake Champlain.
The data collected for Tributary 7 at the Butler Farms/Oak Creek Village lower station*, show an average nitrogen level of 0.82 mg/L. While this is below the 1.47 mg/L national stormwater average, at the lower monitoring station we have observed levels as high as 1.9 mg/L of TKN in isolated incidents.
It has been demonstrated that there are ways by which both phosphorus and nitrogen loading can be significantly reduced. These will be explored in the 'Best Management Practice' section of the toolbox.