LA Water Operator key terms

A treatment step in which a chemical such as alum is mixed rapidly into raw water to neutralize the electrical charges on suspended particles so they can clump together.

Gentle, slow stirring of chemically treated water that encourages tiny destabilized particles to collide and gather into larger, heavier clumps called floc that can settle.

A settling process in which water rests quietly in a basin long enough for heavy floc and suspended solids to sink to the bottom and be removed as sludge.

Passing water through a bed of sand, anthracite, or other media to trap remaining particles and some microorganisms, producing clear water before disinfection.

Treatment that kills or inactivates disease-causing microorganisms in water, usually with chlorine, chloramine, ozone, or ultraviolet light, and leaves a residual to protect stored and distributed water.

The amount of chlorine still present in water after treatment and as it travels through pipes, showing that disinfection capacity remains; it is measured as free or total chlorine.

A measure of how cloudy water is because of suspended particles, reported in nephelometric turbidity units; high turbidity can shield microorganisms from disinfection and indicate treatment problems.

A disinfection calculation that multiplies disinfectant concentration by contact time to express the germ-killing exposure water received; required CT depends on temperature, pH, and the target organism.

Reversing water flow upward through a filter bed to lift and wash out trapped particles, restoring the filter's ability to produce clear water; it is followed by rinsing before service.

A large pipe in the public distribution system that carries treated water along streets to serve many customers, fire hydrants, and smaller service lines.

The pipe that carries water from the public water main to a customer's property and meter; ownership of the line varies by utility and local rules.

A valved connection on a water main used by firefighters and by utility crews for flushing; hydrants also help remove sediment and stagnant water from mains.

A device that automatically lowers high upstream water pressure to a safe, steady downstream pressure, protecting plumbing fixtures and reducing leakage in a pressure zone.

A ground-level or elevated tank that holds treated water to meet peak demands, provide fire flow, and keep pressure steady when pumps are off or demand changes.

A pipe that ends without connecting to another main, allowing water to stagnate; utilities flush these lines and may add looped connections or automatic flushers.

Any actual or potential link between drinking water piping and a source of contamination, such as a submerged hose or a boiler feed line.

Reverse flow of non-potable water or other fluid into the drinking water system, caused by backpressure or backsiphonage and prevented with air gaps or testable backflow assemblies.

The safest backflow prevention method: a physical, unobstructed vertical space between a water outlet and the flood-level rim of the receiving vessel.

A group of bacteria used as an indicator of treatment adequacy and distribution system cleanliness; their presence triggers repeat sampling and corrective action under the coliform rule.

A fecal indicator bacterium whose presence in a drinking water sample signals recent contamination and requires immediate public notification and corrective response.

A laboratory test that counts bacteria able to grow on general-purpose media; it is a broad indicator of water quality and treatment effectiveness, not a health-based standard.

A colorimetric field or laboratory method using a reagent that turns pink in the presence of chlorine, read on a meter to measure free and total chlorine residual.

The maximum time allowed between collecting a water sample and analyzing it, set because chemical and biological changes can make late results invalid.

A written record tracking who collected, handled, and transported a water sample, ensuring its identity and integrity are defensible during regulatory or legal review.

A water sample collected after water has stood motionless in household plumbing for at least six hours, used to assess lead and copper exposure at the tap.

A space large enough to enter, with limited entry and exit, not designed for continuous occupancy, such as a wet well or vault; entry requires testing, a permit, and an attendant.

A safety procedure in which energy sources are shut off, locked, and tagged before workers repair equipment, preventing accidental startup or release of stored energy.

A standardized document listing a chemical's hazards, safe handling, first aid, and spill response, kept available to workers under hazard communication rules.

Gloves, eye protection, respirators, and other gear that create a barrier between a worker and chemical, biological, or physical hazards on the job.

Shoring, shielding, or sloping used in excavations to prevent cave-ins that can crush or trap workers installing or repairing utility lines.

The federal law that authorizes EPA to set drinking water standards and oversees state programs enforcing monitoring, reporting, and treatment requirements for public water systems.

The highest concentration of a regulated contaminant allowed in water delivered to customers, set as close to the health goal as is technically and economically feasible.

A non-enforceable public health goal for a contaminant, set at a level where no known or expected health risk exists with an adequate margin of safety.

A non-health aesthetic standard for qualities such as taste, odor, color, and corrosivity that can make water unpleasant but is not considered a health risk.

The required process for telling customers quickly about violations or emergencies that may affect their health, with timing and wording set by rule tiers.

An annual report each community water system must deliver to customers, summarizing source water, detected contaminants, compliance status, and required health information.

An on-site review by the state of a water system's sources, treatment, storage, distribution, and operations to find health risks and require corrections.

A state-issued credential confirming that a water system operator has the training and exam results required to run a system at a given classification level.

A rule that uses coliform monitoring and assessments to find and fix pathways of contamination in distribution systems rather than relying only on repeat sampling.

A rule requiring systems to sample tap water for lead and copper and, when action levels are exceeded, to optimize corrosion control and replace lead service lines.