13.3 Lockout/Tagout, PPE, Hazard Communication & Excavation

13.3 Lockout/Tagout, PPE, Hazard Communication & Excavation

South Carolina operators work under SC OSHA, the state-plan occupational safety program administered by SCLLR. The standards below are the ones a water or wastewater operator encounters on a normal week.

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1. The Hierarchy of Controls

Controls are applied in this order, and the exam tests the ranking:

$\textbf{Elimination} \rightarrow \textbf{Substitution} \rightarrow \textbf{Engineering} \rightarrow \textbf{Administrative} \rightarrow \textbf{PPE}$

PPE is the LAST line of defense, not the first. If a question offers both an engineering fix and a PPE fix, the engineering control is the better answer.

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2. Lockout/Tagout — Control of Hazardous Energy

LOTO protects against the unexpected energization or start-up of equipment, or the release of stored energy, during servicing and maintenance.

Forms of hazardous energy

Electrical, mechanical (rotating or spring-loaded), hydraulic, pneumatic, chemical, thermal, and gravitational (a raised gate or sludge collector).

The six-step sequence

1. Prepare — identify every energy source for the equipment and notify all affected employees.
2. Shut down using the normal stopping procedure.
3. Isolate every energy source — open the disconnect, close and chain the valve.
4. Apply locks and tags — each authorized employee applies their own lock. A group lock box is used where several trades work simultaneously.
5. Release stored energy — bleed pressure, drain lines, block or lower raised components, discharge capacitors, allow hot surfaces to cool.
6. VERIFY — attempt to start the equipment using the normal controls, confirm it will not run, then return the control to the off position. Test electrically with a meter proven on a known live source.

Step 6 is the one people skip and the one that kills. Verification is a required step. "I turned off the breaker" is not isolation until you have proved the equipment will not start.

The rules about locks

• One lock per authorized employee, with the employee's identification on the tag.
• Only the person who applied a lock may remove it. No exceptions for convenience, shift change, or supervisor authority.
• If a lock must be removed in the owner's absence, a documented removal procedure applies: the employer verifies the employee is not on site, makes all reasonable efforts to contact them, and informs them before they resume work.
• Tags alone are not locks. A tagout-only system is permitted only where a device cannot be locked, and it demands additional safety measures.
• Shift change requires an orderly transfer so protection is continuous — the incoming employee applies their lock before the outgoing employee removes theirs.

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3. Hazard Communication

The Hazard Communication Standard, aligned with the Globally Harmonized System, gives every employee the right to know about the chemicals they work with.

The four elements

1. Written hazard communication program
2. Chemical inventory of every hazardous chemical on site
3. Labels — GHS format with product identifier, signal word, hazard statements, precautionary statements, pictograms, and supplier information
4. Safety Data Sheets, readily accessible to every employee on every shift
5. Training at initial assignment and whenever a new hazard is introduced

Signal words

The 16-section Safety Data Sheet

Sections are standardized and always in the same order. The ones operators reach for most:

Secondary containers must be labeled. A bucket of hypochlorite drawn from a bulk tank and set down unlabeled is a violation and a genuine hazard to the next person who finds it.

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4. Personal Protective Equipment

Glove material must match the chemical — the SDS Section 8 specifies it. Latex is not a chemical glove, and a glove that resists one chemical may dissolve in another.

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5. Excavation and Trenching

Collection and distribution crews dig constantly, and trench collapse is rapidly fatal — a cubic yard of soil weighs roughly as much as a small car.

The core rules

Soil classification

Previously disturbed soil — which describes almost every utility trench in an existing street — is generally classified no better than Type B, and submerged or seeping soil is Type C.

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6. Other Routine Hazards