Oslo Fjord Clean Up - Ren Oslofjord

Monitoring and control of thedisposal facilityArild W SolerødThe Norwegian Geotechnical Institute is responsible for the extensivecontrol and monitoring programme around the disposal facility and thedredging operations. The measurements are carried out as follows:On-line control of turbidity and near-bottomcurrent velocities. Measuring sensors aresuspended three metres above the seabed as wellas at different depths and transmit readingsdirectly to the NGI by SMS.Regular and systematic sampling and analysis ofthe water to ascertain the quantity of heavymetals, PCBs, PAHs and TBTs.Periodic sampling and analysis of sedimentdeposited in sediment traps outside thedisposal site.Measurement of dissolved PCBs and PAHs atdifferent depths using passive samplers to achievea time-integrated sampling.Visual checks by Remotely Operated Vehicle (ROV)Monitoring buoys have been deployed to measureturbidity in the water around the deep-water depositsite. In addition, background turbidity measurementsare monitored from a reference buoy further to thenorth in the Bekkelag Basin.17