OK Water/Wastewater Operator flashcards

33 cards. Read the term and the definition here. The deck at the top of this page is optional.

MCL

Maximum contaminant level: the enforceable highest concentration of a contaminant allowed in public drinking water under the Safe Drinking Water Act, based on health effects and treatability.

CT value

Product of disinfectant residual concentration in mg/L and contact time in minutes. Required CT depends on pH, temperature, and the target log inactivation of pathogens.

Secondary standard

A non-enforceable aesthetic guideline for contaminants such as iron, manganese, chloride, and sulfate that affect taste, odor, color, or staining rather than health.

Lead action level

The 90th-percentile lead concentration of 0.015 mg/L in tap samples. Exceedance triggers corrosion control treatment, public education, and lead service line planning.

TTHM MCL

Total trihalomethanes limit of 0.080 mg/L, evaluated as a locational running annual average under the Stage 2 Disinfectants and Disinfection Byproducts Rule.

Pressure conversion

One psi equals about 2.31 feet of water head. A 100-foot column of water produces roughly 43.3 psi at its base.

Static head

The vertical elevation difference between a water source and discharge point, independent of flow. It determines the pressure available before friction losses.

Total coliform positive

A routine sample containing total coliform triggers repeat sampling at the same and adjacent taps; an E. coli-positive repeat is an acute violation requiring 24-hour notice.

Operator class

Oklahoma certification grade from A (highest) through D, tied to system size and treatment complexity. An operator may serve as chief only at or below their class.

BOD5

Biochemical oxygen demand measured over five days at 20°C. It estimates biodegradable organic matter; untreated domestic wastewater is typically 200–250 mg/L.

Secondary treatment limits

Thirty-day average effluent limits of 30 mg/L BOD5 and 30 mg/L total suspended solids for publicly owned treatment works, with percent-removal alternatives.

F/M ratio

Food-to-microorganism ratio: pounds of BOD applied per pound of MLSS per day. Typical activated sludge values are 0.2 to 0.5.

Sludge age

Solids retention time, calculated as the MLSS inventory divided by the solids leaving the system per day. It controls wasting rate and sludge settling.

RAS

Return activated sludge: settled biomass returned from the clarifier to the aeration basin, typically at 5,000–10,000 mg/L, to maintain the mixed liquor population.

SSO reporting

A sanitary sewer overflow must be reported to Oklahoma DEQ, with public notice and corrective action, because it releases untreated sewage to the environment.

Composite sample

A flow-proportioned or time-proportioned mixture of grab samples collected over a period, used for most NPDES effluent monitoring parameters.

SWPPP

Stormwater Pollution Prevention Plan required under a construction general permit. It identifies best management practices, inspection schedules, and erosion controls before land disturbance.

Dechlorination

Removal of chlorine residual from treated effluent, often with sulfur dioxide or sodium bisulfite, to protect aquatic life from total residual chlorine toxicity.

Construction permit

Oklahoma DEQ approval required before building or modifying water or wastewater facilities. Plans must be sealed by a licensed professional engineer.

Water-sewer separation

Minimum 10 feet horizontal separation between water mains and sanitary sewers. If closer, the sewer must be encased and the water main pressure-tested.

Vertical separation

Water mains crossing above sewers need at least 18 inches clearance. Crossing below a sewer requires encasement of the sewer and pressure testing.

Air gap

The only absolute backflow protection: a physical unobstructed vertical separation between a supply outlet and the flood level of the receiving vessel.

RPZ assembly

Reduced-pressure-zone backflow preventer used for high-hazard cross-connections. It must be tested annually by a certified tester and records retained.

Capacity analysis

A design calculation submitted with a construction permit application showing hydraulic and treatment capacity to serve projected flows and loads.

Pre-construction inspection

An inspection required before operation of newly constructed facilities confirms that construction matches approved plans and that treatment processes function as designed.

Erosion control

Best management practices such as silt fence and sediment basins installed before grading and maintained until final stabilization to prevent sediment discharge.

Watershed

The land area draining to a common outlet or point. It is delineated from topographic maps or digital elevation models by tracing flow paths.

Time of concentration

The travel time for runoff from the hydraulically most distant point to reach the outlet, used as the storm duration in the Rational Method.

Rational Method

Q (cfs) = C × i × A, where C is the runoff coefficient, i is rainfall intensity in inches per hour, and A is area in acres.

TMDL

Total maximum daily load: the maximum pollutant loading a waterbody can receive while meeting standards, allocated among point sources, nonpoint sources, and a margin of safety.

Source water protection

Planning that identifies potential contamination sources within a wellhead or surface intake area and sets management strategies to reduce risk.

Impervious cover

Land surface that prevents infiltration, increasing runoff volume and peak flow. About 10% imperviousness signals stream degradation and 25% severe impairment.

Green infrastructure

Practices such as rain gardens, permeable pavement, and bioswales that infiltrate or detain runoff, reducing volume and pollutant loading to receiving waters.