Biochemical Oxygen Demand (BOD5) and total ammonium concentrations in rivers between 1992 and 2006
Ammonium declined from 800 to 300 ¼g N/l. Number of river monitoring stations included in analysis noted in brackets. BOD5 data from Albania, Austria, Belgium, Bulgaria, Czech Republic, Denmark, France, Hungary, Ireland, Luxembourg, FYR of Macedonia, Poland, Slovakia, Slovenia, Spain and United Kingdom. BOD7 data from Finland, Estonia, Latvia (1996-2001) and Lithuania (1996-2005). BOD7 data were recalculated into BOD5 data. Total ammonium data from Albania, Austria, Belgium, Bulgaria, Denmark, Estonia, Finland, France, Germany, Hungary, Ireland, Latvia, Lithuania, Luxembourg, FYR of Macedonia, Netherlands, Norway, Poland, Slovenia, Spain, Sweden and United Kingdom. Concentrations are expressed as the station weighted mean of the annual mean concentrations by countries. Stations with time series consisting of minimum seven years are included (see Methodology section for further details). The number of available mean concentrations/stations per year is different, except for Luxembourg and Norway with constant number.