After inspecting nurse tanks in several states in 2008 and finding major non-compliance with current laws, the U.S. Department of Transportation (DOT) has issued a safety advisory and is looking at regulatory measures.
Periodic testing of nurse tanks has been required since 2004, following a 2003 nurse tank failure in Calamus, IA. At that time, DOT granted The Fertilizer Institute’s (TFI) request for a special permit for nurse tanks without the required ASME (American Society of Mechanical Engineers) identification plate. The special permit program allows these nurse tanks to remain in transportation so long as certain tests are performed and passed. Those tests are an external visual test, pressure test, and thickness test — all to be conducted every five years.
During November 2008, DOT performed nurse tank inspections in several states and found substantial non-compliance with the current nurse tank testing laws. Therefore, DOT has issued a safety advisory to anhydrous ammonia nurse tank owners and handlers. The advisory describes how to comply with current nurse tank maintenance and testing regulations.
Furthermore, the National Transportation Safety Board calls for testing of all anhydrous ammonia nurse tanks, and DOT is asking industry to guide it in formulating the regulation. A petition for rulemanking from TFI asks that DOT require testing of all anhydrous ammonia nurse tanks. The petition requests that DOT write a rule that is much like the Special Permit Program, with the additional provisions of a five-year phase-in period for compliance and thickness testing on non-plated tanks only. Additionally, the Agricultural Retailers Association pushed for “self-certification” language to also be included in the petition so that facilities may continue to train staff to perform the inspections.
(Source: Agricultural Retailers Association)