NY Water/Wastewater 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 baffled contact time in minutes. Used to demonstrate pathogen inactivation credit under the Surface Water Treatment Rule.

Chlorine demand

Difference between the chlorine dose applied and the residual remaining after contact. Demand must be satisfied before a measurable free residual persists.

Turbidity limit

Combined filter effluent must be at or below 0.3 NTU in 95% of monthly measurements and never exceed 1 NTU. Turbidity indicates filtration effectiveness and pathogen risk.

Filter loading rate

Flow in gallons per minute divided by filter surface area in square feet. Rapid sand filters typically operate at 2 to 4 gpm per square foot.

Langelier Saturation Index

A calculated value describing water's tendency to deposit or dissolve calcium carbonate. Positive is scale-forming, negative is corrosive, and near zero is balanced.

Minimum distribution pressure

New York requires at least 20 psi throughout the distribution system under all conditions, including main breaks. Lower pressure triggers boil-water notification.

Main flushing velocity

Flushing should reach at least 2.5 to 3 feet per second to scour sediment. Velocity equals flow in cubic feet per second divided by pipe area.

BOD5 test

Measures oxygen consumed by microorganisms over five days at 20 degrees Celsius. Typical domestic wastewater influent runs 200 to 250 mg/L BOD.

F/M ratio

Pounds of BOD applied per day divided by pounds of MLSS in the aeration tank. Conventional activated sludge operates around 0.2 to 0.4.

Sludge age (MCRT)

Pounds of MLSS in the aeration tank divided by pounds of solids leaving the system daily. Controls nitrification and settling characteristics in activated sludge.

Sludge Volume Index

Thirty-minute settled sludge volume in mL/L divided by MLSS in mg/L, multiplied by 1,000. Values of 80 to 150 indicate good settling.

Clarifier hydraulic loading

Flow in gallons per day divided by clarifier surface area in square feet. Overflow rate and solids loading rate must both be evaluated for adequate settling.

Infiltration versus inflow

Infiltration enters sewers through defects from groundwater; inflow enters through direct connections such as storm drains and sumps. Both add clear water to treatment.

Sewer design velocity

Collection systems target 2 to 10 feet per second. Lower velocities allow solids to settle; higher velocities cause abrasion and sulfide generation.

Nitrification oxygen demand

Oxidizing ammonia consumes 4.57 mg of oxygen per mg of ammonia nitrogen. Denitrification in anoxic zones returns alkalinity and reduces aeration demand.

Effluent disinfection

Chlorine dose and contact time must achieve fecal coliform limits in the SPDES permit. Dechlorination protects aquatic life in the receiving water.

System classification

New York categorizes public water systems by population and source type: community, non-transient non-community, and transient non-community systems.

Total coliform rule

No more than 5 percent of monthly samples may be positive for systems collecting 40 or more samples. Any E. coli positive requires repeat sampling and public notice.

Lead action level

The 90th percentile lead level must not exceed 0.015 mg/L. Exceedance requires corrosion control, source water treatment, or lead service line replacement.

TTHM limit

Stage 2 Disinfectants/Disinfection Byproducts Rule sets a locational running annual average limit of 0.080 mg/L for total trihalomethanes.

HAA5 limit

Locational running annual average limit of 0.060 mg/L for five haloacetic acids under the Stage 2 Disinfectants/Disinfection Byproducts Rule.

Surface Water Treatment Rule

Requires 99.9 percent Giardia and 99.99 percent virus removal or inactivation. Achieved through combined filtration and disinfection CT credits.

Consumer Confidence Report

Annual water quality report delivered to customers by July 1. Lists detected contaminants, source water, and health effects, with prior-year monitoring data.

Public notification tiers

Tier 1 requires notice within 24 hours for acute health risks. Tier 2 allows 30 days and Tier 3 allows annual notice for less urgent violations.

Backflow prevention

Air gaps, reduced pressure zone assemblies, and double check valves stop reverse flow. Containment is required at service connections under New York regulations.

SPDES permit

New York State Pollutant Discharge Elimination System permit. Sets enforceable effluent limits, monitoring frequency, and reporting deadlines for discharges to surface waters.

Discharge Monitoring Report

Monthly or permit-specified report of effluent monitoring results. Late or inaccurate reports are permit violations subject to enforcement and penalties.

Confined space testing order

Test oxygen first, then combustible gases, then toxic gases. Acceptable oxygen is 19.5 to 23.5 percent, and entry requires a permit and attendant.

Hydrogen sulfide IDLH

Immediately dangerous to life or health concentration is 100 ppm. Methane lower explosive limit is 5 percent in air, and carbon monoxide IDLH is 1,200 ppm.

Chlorine gas detection

Chlorine is heavier than air and pools at low points. Aqueous ammonia forms a white cloud at leaks. Entry requires SCBA and a standby person.

Lockout/tagout

Isolate all energy sources, verify zero energy, and apply locks and tags. Only the person who applied a lock may remove it.

Chemical dose formula

Pounds per day equals dose in mg/L times flow in MGD times 8.34. Used to set chlorine, alum, polymer, and fluoride feed rates.