Hydrocarbon leakage, from Underground Storage Tanks (USTs) and from the bottoms of above- ground tanks, can seep into the groundwater, where it forms a floating oil sheen, growing to a thick oil layer over time. This layer, if left undetected, will eventually dissolve and cause severe damage to water quality. Health standards in some countries allow a maximum concentration of only a few PPBs of hydrocarbons and other organic solvents in drinking water. This translates to a quantity of 1 liter of hydrocarbon being able to contaminate several million liters of drinking water resources, which become scarce as the population increases.

Remediation of contaminated groundwater involves extremely high costs. It is therefore essential to use reliable on-line leak detection system that can detect the smallest leaks and give an early warning, thus reducing the damage and costs as much as possible. The Leakwise ID-221 Oil Sheen Detector was designed to make this possible.