Casing shall not be recovered if its recovery will expose any abnormal pressure, lost circulation, oil, gas, or water zone. In pulling outside strings of casing from any oil or gas well, the space outside the casing left in the hole shall be kept and left full of mud-laden fluid of adequate specific gravity to seal off all fresh and saltwater strata and any strata bearing oil or gas which is not producing. Casing may not be pulled without first making application to the Department and receiving approval. The application must describe how fresh waters will be protected.
Idaho Admin. Code r. 20.07.02.315