KS Water Operator flashcards

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

CT value

Product of disinfectant residual concentration in mg/L and contact time in minutes; used to demonstrate required log inactivation of Giardia, viruses, and other pathogens.

Jar test purpose

Bench-scale test that simulates coagulation, flocculation, and settling to determine optimum coagulant dose, pH, and mixing conditions before full-scale adjustment.

Breakpoint chlorination

Point where applied chlorine has oxidized ammonia and other demand; beyond it, additional chlorine produces a free chlorine residual that increases almost linearly with dose.

Combined filter effluent turbidity

Under the Surface Water Treatment Rule, must be 0.3 NTU or less in at least 95 percent of monthly measurements and never exceed 1 NTU.

Chlorine demand

Difference between the chlorine dose applied and the residual remaining after a specified contact time; reflects consumption by organics, ammonia, iron, and other reducing agents.

Fluoride MCL

Primary maximum contaminant level is 4.0 mg/L; the secondary standard is 2.0 mg/L, and many systems target about 0.7 mg/L for dental benefits.

Filter backwash triggers

Backwash is initiated by terminal head loss, typically 6 to 8 feet, or by turbidity breakthrough, or by run time limits set in the plant operating plan.

Minimum distribution residual

Typical requirement is 0.2 mg/L free chlorine or 0.5 mg/L chloramine at the farthest sampling point; primacy states may set stricter values.

Air gap

Physical separation between a potable water outlet and the flood level rim of a receiving vessel; provides the highest level of backflow protection.

Hazen-Williams formula

Empirical head loss equation: hL = 4.52 Q raised to 1.85 divided by C raised to 1.85 times d raised to 4.87, with Q in gpm and d in inches.

Main repair disinfection

After repair, the main is chlorinated, typically to 25 mg/L for 24 hours or 50 mg/L for 24 hours, then flushed and sampled for bacteriological clearance.

Dead-end main flushing

Periodic or automatic flushing prevents stagnation, sediment buildup, and loss of disinfectant residual at the ends of distribution branches.

Specific capacity of well

Pumping rate in gallons per minute divided by drawdown in feet; indicates well efficiency and declines as the aquifer or screen becomes clogged.

Cone of depression

Drawdown shape around a pumping well; overlapping cones from nearby wells can cause interference and reduce yield.

Confined aquifer

Groundwater unit bounded above and below by low-permeability layers; water is under pressure and wells may flow without pumping.

Nitrate MCL

Maximum contaminant level is 10 mg/L measured as nitrogen; common sources are fertilizer, manure, and septic systems, and it causes methemoglobinemia in infants.

Arsenic MCL

Maximum contaminant level is 0.010 mg/L; treatment includes coagulation with filtration, ion exchange, and adsorptive media such as granular ferric hydroxide.

E. coli significance

Indicator of fecal contamination in drinking water; a positive result triggers repeat sampling, investigation, and public notification requirements.

Wellhead protection area

Land surface and subsurface area through which contaminants could reach a public water supply well; delineated by fixed radius or hydrogeologic methods.

Primary versus secondary standards

Primary standards are enforceable health-based limits such as MCLs; secondary standards are non-enforceable aesthetic guidelines for color, odor, and similar qualities.

Public notice tiers

Tier 1 requires notice within 24 hours for acute violations; Tier 2 within 30 days; Tier 3 in the annual report or as state rules specify.

Consumer Confidence Report

Annual water quality report that community water systems must deliver to customers by July 1, listing contaminants detected, sources, and health information.

Lead action level

0.015 mg/L based on the 90th percentile of first-draw samples; exceedance triggers corrosion control, source water treatment, and public education requirements.

TTHM and HAA5 limits

Disinfection byproduct MCLs are 0.080 mg/L for total trihalomethanes and 0.060 mg/L for five haloacetic acids, evaluated as locational running annual averages.

Total coliform positive limit

For systems collecting 40 or more routine samples monthly, no more than 5 percent may be total coliform positive; smaller systems have fixed maximums.

Confined space oxygen range

Acceptable entry atmosphere is 19.5 to 23.5 percent oxygen; outside this range, ventilation and reassessment are required before entry.

Chlorine gas hazard

Chlorine gas is heavier than air and accumulates in low areas; it requires supplied-air respiratory protection and immediate evacuation when leaks occur.

Trench protective systems

At 5 feet or deeper, protective systems such as sloping, shoring, or shielding are required; spoil and equipment must be kept at least 2 feet from the edge.

Lockout tagout purpose

Hazardous energy control procedure that isolates pumps, blowers, and electrical equipment before maintenance to prevent unexpected startup or release of stored energy.

Cost per thousand gallons

Total annual cost divided by annual production in thousands of gallons; used to compare treatment or distribution options and to support rate setting.

Water loss percentage

Produced water minus billed water divided by produced water, times 100; values above roughly 10 to 15 percent suggest leakage or metering problems.

Asset criticality

Ranking of assets by consequence of failure and likelihood of failure; used to prioritize maintenance, repair, and capital replacement spending.