Correctly cite DOT cargo tank specification differences when speccing a truck for potable vs. non-potable water hauling

Steps

1. Understand that DOT 406 (49 CFR 178.346) and DOT 407 (49 CFR 178.347) are hazmat cargo tank specifications built primarily for flammable liquids and chemicals respectively — not the applicable framework for plain water hauling
2. Recognize that water (potable or non-potable, non-hazardous) is commonly hauled in 'non-code' tanks, meaning tanks built to a manufacturer's or industry design standard rather than a DOT hazmat cargo-tank specification
3. For potable water tanks, prioritize food-safe interior materials (stainless steel or NSF/ANSI 61-certified lined carbon steel) and dedicated, labeled fittings, matching the state hauler equipment rules (e.g., Texas's 30 TAC 290.44(i)(2)) rather than a hazmat DOT spec
4. For non-potable tanks (dust control, irrigation, oilfield), carbon steel or polyethylene construction is common since food-grade material isn't required, but cross-contamination prevention still matters if the same fleet ever also hauls potable water
5. Confirm with your state PWS/hauler program which equipment approval actually governs your tank (state drinking-water rule) rather than assuming a DOT hazmat cargo tank spec applies to a non-hazmat water load