Total Kjeldahl Nitrogen (TKN)

Status and Trends

Total Kjeldahl nitrogen is a measure of the concentration of reduced forms of nitrogen in surface water, principally, ammonium and amino forms of organic nitrogen. TKN plus NO₂₃ is the method used to derive a value for total nitrogen in the nontidal Core/Trends data set.

Median concentration of total Kjeldahl nitrogen ranged from 0.205 mg/L at the mouth of the Savage River to 0.682 mg/L on the Monocacy River at Reels Mill Road. Two stations (4% of all stations) of the Monocacy River (Bridgeport and Reels Mill Road) had median TKN concentrations in the upper tercile of the benchmark data set. The preponderance (70%) of stations, however, fell in the tercile of lowest concentration (i.e. TKN < 0.48 mg/L) while 26% of stations had median concentration in the intermediate range.

Trends in TKN concentration were all decreasing and occurred at 80% of the stations. TKN, a measure of all the reduced forms of nitrogen (e.g. NH₄) was the dominant form of nitrogen at 24% of stations

Total Kjeldahl Nitrogen (TKN) data for sampled locations are summarized in these plots.

• Land use/site map

Search Maryland DNR

Rivers & Streams 101 | Monitoring & Research | Restoration & Protection
Want Data? | Meetings & Readings | Get Involved!

Return to the Maryland DNR Home Page.
Your opinion counts! Take a survey!
This page was updated on 12/5/2005