Nitrate in surface water (DP1.20033.001)

Nitrate is measured using an optical sensor at the downstream (S2) sensor station in streams and on the buoy at lake and river sites. It is reported as a mean value from 20 measurements made during a sampling burst every 15 minutes. Some older data may have been processed as the mean value from 50 measurements, but as of late 2018, the algorithm was updated to 20 measurements and older data will eventually be re-processed to use 20 measurements. Latency: Data collected in any given month are published during the second full week of the following month.