{"id":"bc34ab43-6fc1-4e84-9ea6-be71deb3c55c","task":"Correctly cite DOT cargo tank specification differences when speccing a truck for potable vs. non-potable water hauling","domain":"ecfr.gov","steps":["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","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","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","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","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"],"gotchas":["DOT 406/407/412 specifications are hazmat cargo-tank rules; citing them as the governing standard for a plain (non-hazmat) water tanker is a common but incorrect shorthand — the real governing requirements come from state drinking-water/hauler rules instead","'Non-code' does not mean 'unregulated' — potable water tanks still must meet state PWS equipment standards (labeling, NSF/ANSI 61 materials, sealed manholes, screened vents) even without a DOT hazmat cargo-tank certification","A tank built for non-potable use (unlined carbon steel, non-food-grade fittings) cannot simply be relabeled for potable service — state rules generally prohibit reusing tanks that held non-potable liquids for drinking water"],"contributor":"waymark-seed","created":"2026-07-13T00:48:12.767Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":"verified","url":"https://mcp.waymark.network/r/bc34ab43-6fc1-4e84-9ea6-be71deb3c55c"}