MD Water Operator key terms

The rapid mixing of a chemical such as alum into raw water so that small particles destabilize and clump together, allowing later settling and filtration to remove them.

Gentle, slow stirring after coagulation that encourages destabilized particles to collide and grow into larger, heavier clumps called floc that settle out more readily.

A treatment stage where water sits in a basin long enough for heavier particles and floc to settle to the bottom as sludge before the water moves on to filtration.

Passing water through a bed of sand, anthracite, or other media to physically remove remaining suspended particles, and often some pathogens, before disinfection.

Reversing or scouring flow through a filter to flush out trapped particles and restore flow capacity, after which the filter is returned to service carefully to avoid turbidity spikes.

The process of inactivating or killing disease-causing microorganisms in water, usually with chlorine, chloramine, ozone, or ultraviolet light, without necessarily removing all organisms.

The product of disinfectant concentration in milligrams per liter and contact time in minutes, used to show that a required level of pathogen inactivation has been achieved.

A measure of how cloudy water is because suspended particles scatter light, expressed in nephelometric turbidity units; high readings can shield pathogens from disinfection.

A bench-scale procedure that stirs several beakers of raw water with different coagulant doses to identify the best chemical dose and mixing conditions for the plant.

The concentration of disinfectant that remains in treated water after contact time, which protects against contamination as water travels through the distribution system.

The network of pipes, pumps, storage tanks, valves, and hydrants that carries finished drinking water from the treatment plant to homes, businesses, and other customers.

A large buried pipe that carries water along streets and serves as the backbone of the distribution network, from which smaller service lines branch to individual properties.

The pipe that connects an individual building or customer to the public water main, often owned partly by the utility and partly by the property owner.

A defined area of the distribution system kept within a target pressure range by pumps, valves, or storage tanks so that adequate pressure reaches every customer.

A sharp pressure surge caused by a sudden change in flow, such as a rapidly closing valve, which can damage pipes, joints, and fittings.

Any actual or potential link between drinking water piping and a source of nonpotable water or contamination that could allow backflow into the distribution system.

Devices and practices such as air gaps, reduced-pressure assemblies, and vacuum breakers that stop water from flowing backward from a customer's plumbing into the public supply.

A pipe segment that ends without connecting to another main, where water moves slowly, allowing sediment buildup and loss of disinfectant residual.

Deliberately running water through mains, hydrants, or dead ends to remove sediment, stale water, and biofilm and to restore disinfectant residual in the distribution system.

Water from rivers, lakes, reservoirs, or streams that is open to the environment and therefore requires more extensive treatment than most groundwater.

Water held in underground aquifers and drawn from wells or springs, typically clearer and less contaminated than surface water but sometimes high in minerals.

The land area that drains runoff into a particular river, lake, or reservoir, whose land uses strongly influence the quality of the source water.

Managing the land area around a drinking water well to prevent contaminants from reaching the aquifer that supplies it.

A study of a water system's source and surrounding land to identify potential contaminant threats and determine how susceptible the supply is to them.

A rule requiring utilities to monitor for coliform bacteria throughout the distribution system as an indicator of possible contamination or treatment failure.

Bacteria associated with the intestines of warm-blooded animals; their presence in drinking water signals likely contamination by sewage or animal waste.

The highest concentration of a regulated contaminant allowed in drinking water, set as close to the health goal as practical given available treatment technology and cost.

A nonenforceable health-based target for a contaminant, set at a level with no known or expected health risk and used to guide the enforceable limit.

The scheduled collection and laboratory analysis of water samples at required locations and frequencies to demonstrate compliance with drinking water standards.

An annual report that every community water system must deliver to its customers describing source water, detected contaminants, and compliance with drinking water regulations.

A public warning telling customers to boil tap water before drinking or cooking because contamination is confirmed or a treatment barrier has failed.

A written record tracking who collected, handled, and transported a water sample, and when, so results can be trusted in compliance decisions.

The unit reported by a turbidimeter, which measures light scattered by particles in a water sample and is used to judge filtration performance.

A space such as a vault, tank, or pit that is large enough to enter, has limited entry and exit, and is not designed for continuous occupancy, requiring a permit to enter.

A dangerous condition in the air of a work area, such as oxygen deficiency, toxic gas, or flammable vapor, that must be tested before and during entry.

A safety procedure that isolates energy sources such as electricity, pumps, or valves and applies locks and tags so equipment cannot start during maintenance.

The required process of informing customers about violations, health risks, and corrective actions, with content and timing set by the seriousness of the problem.

The state-issued credential that qualifies an individual to operate a water system, typically granted by examination and graded by system size and treatment complexity.

Training hours an operator must earn and document to renew certification, keeping knowledge current on treatment, regulations, and safety practices.