The NFPA 22 standard references AWWA guidelines, especially when a tank is intended for dual-purpose use – fire suppression and human consumption. However, as many tanks will only serve the purpose of fire suppression, they won’t ever hold water meant for human consumption. Herein lies the crossroads for many project managers and designers.
Given the dual-purpose possibility, a tank could be designed with a liner suitable for potable (drinkable) water. However, if the Fire Marshall, after reviewing the project requirements, determines that the tank will only ever be used for fire suppression, a non-potable liner may be approved.