Unless you are recording actual release detection results at least every 30 days and maintaining records for at least 5 years, you are not doing leak detection.  Keep all records of calibration, maintenance, and repair of your release detection equipment for at least 5 years.eep These O&M Records  Keep your manual tank gauging records for at least 5 years. Unless you are recording actual release detection results at least weekly and every 30 days and maintaining records for at least 5 years, you are not doing leak detection right.