Construction of the Oslo, Norway airport, was authorized on condition that water supplies be protected from the effects of deicing chemicals and jet fuel. To accomplish this, the soil in vulnerable areas was replaced with material containing microorganisms that digest the harmful chemicals. To monitor the effectiveness of the filters, the Norwegian Campbell Scientific representative, Instrument Tjenesten AS, delivered two CR10X-based systems. The system for monitoring deicing chemicals measures conductivity, temperature, redox potential, soil humidity and water run-off in the drainage system. Water samplers are also controlled. The system at the jet fuel site monitors 16 soil temperatures, 16 soil humidity probes, two water level sensors and water run-off (at 6 m depth) with eight tipping bucket rain gages.