Inside Our 7-Stage Tote Cleaning Process

Stage 1 — Intake grading

Every tank gets a physical inspection, a label review, and a contents history check on intake. We won't recondition tanks whose prior contents disqualify them — PCBs, certain pesticides, and a short list of pharmaceuticals are non-negotiable rejects.

Tanks are tagged with an intake lot number that follows them through the rest of the process so we can always reconstruct what was done to a given unit and when.

Stage 2 — Caustic wash

Interior wash with hot sodium hydroxide solution at controlled temperature and dwell. The wash chemistry is calibrated to remove typical industrial residues without stressing the HDPE. We rotate caustic concentrations and dwell times based on prior-contents class — a glycol tank gets a different recipe than a surfactant tank.

Stage 3 — Neutralization and rinse

Neutral rinse to bring interior pH back to spec, with a verification step using pH strips on samples drawn from each tank. Effluent goes to our on-site treatment system, where pH is buffered before discharge to the municipal system.

Stage 4 — Exterior pressure wash

Cage, pallet, valve body, and lid receive a hot exterior wash. Labels and stickers come off here to avoid placard confusion downstream — a tank with a former hazmat sticker still on it is a paperwork problem waiting to happen.

Stage 5 — Valve service

New gaskets, cam-lock cap (or specified fitting), and a seat leak-test. Failed valves get swapped from our parts pool — we keep two-inch ball and butterfly valves in inventory by the pallet.

Stage 6 — Pressure and leak test

Per the regulatory rating the tank will carry, including UN requalification testing where applicable. Pressure profile is logged for each tank to support 49 CFR documentation.

Stage 7 — Final QC and grade card

Outgoing inspector signs off, attaches the physical grade card, photographs the unit for the lot record. The grade card is what your receiving dock will look at — date, grade, prior-contents class, lot number.