CA Water Operator flashcards
CA Water Operator · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Turbidity
- Turbidity measures light scattering by suspended particles in water, reported in nephelometric turbidity units (NTU). It indicates clarity but does not directly measure pathogen concentration.
- Total organic carbon
- Total organic carbon (TOC) is the concentration of organic carbon in water. It serves as a precursor indicator because organics react with disinfectants to form disinfection byproducts.
- Alkalinity
- Alkalinity is water's acid-neutralizing capacity, usually reported as mg/L calcium carbonate. It buffers pH changes during coagulation, disinfection, and corrosion control.
- Source water assessment
- A source water assessment identifies contaminants and susceptibility for a drinking water source. It evaluates potential contamination sources, intrinsic vulnerability, and monitoring needs to guide protection.
- pH scale
- The pH scale ranges from 0 to 14, with 7 neutral. Lower pH is acidic and often corrosive; higher pH is basic and can promote scale and reduce some disinfection efficacy.
- Coagulation
- Coagulation destabilizes suspended particles and natural organic matter by adding chemicals such as alum or ferric salts. Charge neutralization lets particles collide and stick together.
- Flocculation
- Flocculation is gentle, prolonged mixing after coagulation that encourages destabilized particles to collide and form larger, settleable flocs without breaking them apart.
- Jar test
- A jar test simulates coagulation, flocculation, and settling at several chemical doses. Operators select the lowest dose that produces clear settled water and manageable floc.
- Surface loading rate
- Surface loading rate equals flow divided by clarifier surface area, often expressed as gpm per square foot. Lower rates generally improve particle settling and effluent clarity.
- Filter backwash
- Filter backwash reverses flow through media to remove accumulated particles. It is triggered by head loss, turbidity breakthrough, or a set run time.
- Chemical feed dose
- Chemical feed dose in mg/L equals pounds per day divided by the product of flow in MGD and 8.34. This converts a mass feed rate to concentration.
- CT value
- CT is disinfectant residual concentration in mg/L multiplied by effective contact time in minutes. It estimates disinfection exposure and is adjusted for pH, temperature, and basin baffling.
- Chlorine demand
- Chlorine demand is the difference between chlorine dose and the residual remaining after contact. It reflects reactions with organics, ammonia, metals, and other reducing substances.
- Trihalomethanes
- Trihalomethanes are disinfection byproducts formed when chlorine reacts with natural organic matter, especially bromide-containing water. TTHM is regulated as a group of four compounds.
- Haloacetic acids
- Haloacetic acids are chlorine disinfection byproducts formed from organic precursors. HAA5 is regulated as the sum of five haloacetic acid species in distribution water.
- Chloramines
- Chloramines form when chlorine reacts with ammonia. Monochloramine is a weaker but longer-lasting disinfectant that can reduce trihalomethane formation but requires nitrification control.
- UV disinfection
- Ultraviolet disinfection inactivates pathogens by damaging nucleic acids. It is effective against Cryptosporidium, produces no disinfectant residual, and requires clear water for adequate dose.
- Air gap
- An air gap is a physical separation between a potable water outlet and the flood level of a contaminating source. It provides the highest level of backflow protection.
- Backsiphonage
- Backsiphonage is backflow caused by negative pressure in the potable system. It can draw contaminants into drinking water through a cross-connection when supply pressure drops.
- Unidirectional flushing
- Unidirectional flushing uses sequenced valves to create high-velocity flow in one direction. It removes sediment and biofilm while avoiding contaminant spread to other mains.
- Water age
- Water age is the time water resides in storage or distribution. High age can lower disinfectant residual and increase disinfection byproducts, nitrification, and stagnation problems.
- Reduced pressure zone
- A reduced pressure zone assembly is a testable backflow preventer with two check valves and a relief valve. It protects against high-hazard backflow and requires annual testing.
- Total dynamic head
- Total dynamic head is the total energy a pump adds, expressed in feet. It includes elevation, pressure, velocity, and friction head terms.
- Cavitation
- Cavitation occurs when local pressure drops below vapor pressure, forming vapor bubbles that collapse. It causes noise, vibration, erosion, and reduced pump performance.
- Affinity laws
- Pump affinity laws state that flow varies with speed, head with speed squared, and power with speed cubed for geometrically similar pumps at constant impeller diameter.
- Magnetic flowmeter
- A magnetic flowmeter measures flow using Faraday's law: conductive fluid moving through a magnetic field generates a voltage proportional to velocity. It requires a full pipe and conductive water.
- 4-20 mA signal
- A 4-20 mA current loop represents an instrument measurement, with 4 mA at zero percent and 20 mA at full scale. It is common for transmitters and controllers.
- Lead action level
- The lead action level is 0.015 mg/L at the 90th percentile of customer tap samples. Exceeding it triggers corrosion control treatment, public education, and sampling changes.
- TTHM MCL
- The Stage 2 TTHM maximum contaminant level is 0.080 mg/L, calculated as a locational running annual average at each monitoring location.
- Consumer confidence report
- A consumer confidence report summarizes annual drinking water quality, including detected contaminants, regulated limits, and health effects. Community water systems must deliver it to customers by July 1.
- Confined space entry
- Confined space entry requires a permit, atmospheric testing, ventilation, an attendant, and retrieval equipment. Never enter a permit-required space without trained rescue arrangements.
- Public notification tiers
- Public notification rules require water systems to inform customers of violations. Tier 1 is immediate for acute risks, Tier 2 within 30 days, and Tier 3 within one year.