NRA wastewater treatment plant, Norway

Lillestrøm, Norway

Photo: NRA, Lillestrøm

Nedre Romerike Avløpsrenseanlegg (NRA) is the first wastewater treatment plant (wwtp), practicing the DOSCON coagulant control system. The system was researched and developed in the same wwtp during the period 2008 to 2009. From May 2009, DOSCON is successfully controlling the coagulant dosage for the chemical treatment process of NRA, with significant advantages.


  • DOSCON control system is successfully operated with well controlled optimal dose prediction in NRA WWTP.
  • During last three years, even with poor system maintenance in 2010, DOSCON has achieved the expected treatment qualities with great savings of coagulants.
  • DOSCON system has saved ca. 470 tons coagulant per year, with compared to the base year 2008. This counts ca. 710 000 NOK savings per year.
  • Additionally, it reduces ca. 315 tons of sludge (33%) per year, resulting much more savings like sludge treatment costs, transportation costs, risks and environment pollution etc.
  • A system based on multiple models was used to eliminate malfunctioning parameters from dose prediction. Still it is very essential to maintain the malfunctioning instruments promptly
  • The treatment plant has a new effluent demand of 93% TP removal from the year 2013. Also NRA plans to minimise the overflow water quantity by increase the plant’s maximum intake capacity up to 1400l/s.

Photo: NRA, Lillestrøm

Wastewater treatment plant (WWTP) NRA is built in a tunnel of a rock at Lillestrøm, Norway. This WWTP serves the population in three municipalities and several small and large scaled industries in the area. Presently the plant is running with a capacity of about 110 000 p.e. with around 50,000 m3//day.