Debunking Common Misconceptions About §5164: Hazardous Substance Storage in Water Treatment Facilities

In water treatment plants across California, §5164 of Title 8 CCR governs the storage of hazardous substances—from chlorine cylinders to sulfuric acid drums. Yet, we've seen teams trip over the same myths time and again during audits. These misconceptions can lead to citations, spills, or worse. Let's cut through the noise with facts grounded in Cal/OSHA regs and real plant scenarios.

Misconception 1: §5164 Only Applies to Flammable Liquids

Water ops folks often think §5164 targets just flammables like solvents or fuels. Wrong. It covers a broad swath: flammable liquids, compressed gases, toxics, corrosives—pretty much anything hazardous per §5155 definitions.

Take chlorine gas storage, common in disinfection setups. §5164.1 mandates approved cabinets for indoor storage exceeding portable quantities. We've consulted plants where operators stored hypochlorite drums unchecked, assuming 'non-flammable' meant exempt. A Cal/OSHA inspector flagged it under §5164(b) for lacking secondary containment, resulting in a $10K fine. Check the full scope in CCR Title 8 §5164.

Misconception 2: Small Quantities in Process Areas Are Always Okay

"It's just a few gallons near the mixer—no big deal." That's a trap. §5164 sets strict maximums per cabinet (60 gallons Class I/II liquids) and requires separation from ignition sources.

In one SoCal facility, we found alum and polymer totes staged too close to electrical panels during flocculation ops. Exceeding incidental storage allowances under §5164(c) invited vapor ignition risks. Pro tip: Use the table in §5164 Appendix A for quantity limits. Even 'small' adds up fast in high-throughput plants.

Misconception 3: Cabinets Don't Need Ventilation or Grounding

Many assume any FM- or UL-approved cabinet suffices. Not quite—§5164.1(c) demands self-closing doors, spill containment, and for flammables, bonding/grounding to prevent static sparks.

We've retrofitted plants storing ferric chloride where cabinets vented poorly, building toxic vapors. Per NFPA 30 (cross-referenced in Cal/OSHA interpretations), mechanical ventilation at 1 cfm/ft² is often required. A quick anecdote: During a walkthrough, ungrounded acid cabinets sparked a near-miss with a metal drum. Ground straps aren't optional; they're code.

• Actionable fix: Inspect cabinets quarterly for seals, labels per §5164.2, and test grounding with a multimeter.
• Bonus: AWWA's G100 offers water-specific storage guidelines that align seamlessly with §5164.

Misconception 4: Water Treatment Exemptions Cover Everything

Some claim process-integrated storage sidesteps §5164 via 'operational necessity.' Nope—§3204 of the Hazard Communication Standard reinforces storage rules, no carve-outs for utilities.

Coagulant day tanks in a Bay Area plant overflowed without diking, per §5164(d) spill control mandates. EPA's RMP rules layer on, but Cal/OSHA leads for workplaces. Research from the Water Research Foundation shows compliant storage slashes incident rates by 40%. Balance both regs for airtight compliance.

Misconception 5: Labels and Segregation Are Overkill Indoors

"Everyone knows what's inside." Sloppy thinking. §5164.2 requires NFPA 704 placards on cabinets/rooms, plus segregating incompatibles (acids from bases) per §5165.

Picture this: Lime slurry next to coagulant acids, risking violent reactions. We've mediated post-incident reviews where faded labels fueled confusion. Indoor or not, segregation distances apply—12 inches minimum, more for toxics. Transparent? Always label with GHS pictograms too, bridging HazCom.

Bottom line: §5164 storage of hazardous substances in water treatment facilities demands precision. Bust these myths, audit your setups against the code, and reference Cal/OSHA's enforcement logs for precedents. Your plant—and your team—will thank you.