New state and federal regulations due to go into effect December 1998 require underground tanks to be equipped with corrosion control features such as plastic linings, cathodic protection, etc. Cathodic protection is a way of preventing corrosion by imposing an electric field on metal objects in contact with the soil. Since the tanks did not have these features they had to be either upgraded to include them or removed and replaced with tanks complying with the requirements. Leaking underground storage tanks are a big environmental problem all over the USA and in other countries. These leaks can cause problems like contaminating groundwater and drinking wells, seeping into basements, etc., and causing fire and explosion hazards or seeping into creeks and contaminating surface water supplies.
Most leaks occur due to corrosion of the tanks or their piping, or due to spills and overfills.
The regulations are designed to prevent these problems. To achieve compliance at the facility in our example, the client hired a contractor to remove the underground tanks, clean and dispose of them. My company was hired to watch the contractor work and inform the client as to the quality of the work and degree of compliance with regulations governing these types of removals. We also performed the site assessment required by the regulations by looking for signs of a petroleum release in the piping trenches or the underground tank pit, collecting samples for laboratory analyses and preparing a report to the state environmental agency. Such a release had occurred.