Most local authorities realize that leaks associated with a dual wall secondary containment tank are usually the result of overfilling, plumbing leaks or drips from filling the tank. It is important to note that NFPA 30 2-3.4 and most of the other fire codes all have requirements for conditions that have to be met when using above ground secondary containment tanks. These provisions are important not only to protect your facility, but also to protect the environment. NFPA 30 has limitations on the capacity of secondary containment-type tanks when diking or remote impounding is not used. Always check with your local fire code authority for possible restrictions.