ADEQ Water Treatment grade 2 practice test V2

What is the primary purpose of the Safe Drinking Water Act (SDWA)?

To protect public drinking water supplies.

How often does ADEQ require water systems to report bacteriological samples?

Quarterly.

What does an MCL represent?

Maximum Contaminant Level.

Which PPE is most important when handling chlorine?

Respirator.

What is a confined space?

A space with limited entry and exit.

What gas is commonly used for disinfection in water treatment?

Chlorine.

Who is responsible for ensuring compliance at a water treatment plant?

Certified operator.

What is the required chlorine residual in a distribution system?

Detectable.

Which form of chlorine is most hazardous?

Chlorine gas.

What information do MSDS sheets provide?

Chemical hazards.

What are lockout/tagout procedures used for?

To prevent accidental equipment startup.

Which agency enforces drinking water regulations in Arizona?

ADEQ.

Why are cross-connections dangerous?

They allow contamination.

What does backflow prevention protect against?

Reverse flow.

Which record must be kept the longest?

Bacteriological results.

What does a pH below 7 indicate about water?

It is acidic.

What does turbidity measure?

Cloudiness.

What is the unit for turbidity?

NTU.

What does alkalinity help water resist?

pH changes.

What chemical increases alkalinity?

Lime.

What primarily causes hardness in water?

Calcium and magnesium.

What is jar testing used to determine?

Coagulant dose.

What does coagulation primarily remove?

Suspended particles.

What is the purpose of flocculation?

To form larger particles.

At what pH range does alum work best?

6-8.

Which test measures chlorine residual?

DPD test.

What does TDS stand for?

Total Dissolved Solids.

Increasing temperature will ______ chlorine demand.

Increase.

What issues does iron in water cause?

Staining and taste issues.

What often causes black staining in water?

Manganese.

What unit is alkalinity measured in?

ppm as CaCO₃.

What chemical is commonly used for fluoridation?

Sodium fluoride.

What is the maximum fluoride level allowed?

4.0 mg/L.

What may a sudden drop in pH indicate?

Chemical overfeed.

What is the first step in conventional treatment?

Coagulation.

How does sedimentation remove particles?

By gravity.

What does detention time refer to?

Time water spends in a basin.

What does short-circuiting in a basin cause?

Reduced treatment efficiency.

When does rapid mix occur?

During coagulation.

What does filter media commonly include?

Gravel and sand.

What does backwashing a filter remove?

Settled floc.

What does excessive headloss indicate?

Clogged filter.

What type of filter uses biological action?

Slow sand.

What does GAC remove?

Taste and odor.

What does disinfection effectiveness depend on?

CT value.

What does CT stand for?

Concentration × Time.

How does UV disinfection work?

By damaging DNA.

What is ozone?

Ozone is a strong oxidant used for water treatment, and it is less effective than chlorine but highly stable.

What do chloramines provide?

Chloramines provide long-lasting residual disinfection in water treatment.

What is the purpose of a contact basin?

A contact basin is used for disinfection in water treatment processes.

What increases disinfection efficiency?

Low pH increases disinfection efficiency.

What is a clearwell?

A clearwell is a storage basin after treatment in water treatment systems.

Which process removes dissolved organic matter?

GAC (Granular Activated Carbon) adsorption removes dissolved organic matter.

What can excessive alum dosage cause?

Excessive alum dosage can cause a drop in pH.

What is the main purpose of distribution storage tanks?

The main purpose of distribution storage tanks is to provide pressure and storage for treated water.

What can dead-end mains cause?

Dead-end mains can cause stagnation in the water distribution system.

What causes water hammer?

Water hammer is caused by a sudden flow change in the water system.

What is the function of a booster pump?

A booster pump is used to increase flow and pressure in the water distribution system.

What is the minimum system pressure generally?

The minimum system pressure is generally 20 psi.

How do elevated tanks work?

gravity to create water pressure

What does flushing hydrants help to do?

Flushing hydrants helps to remove sediments from the water distribution system.

What do cross-connection control programs prevent?

Cross-connection control programs prevent backflow in the water distribution system.

What device prevents backsiphonage?

A check valve prevents backsiphonage in water systems.

What does distribution system sampling check for?

Distribution system sampling checks for bacteria and residual chlorine.

How often should storage tanks be inspected?

Storage tanks should be inspected periodically.

What does low chlorine residual indicate?

Low chlorine residual may indicate contamination in the water.

What causes nitrification?

Nitrification is caused by chloramines in the water.

What are distribution maps used for?

Distribution maps are used to locate valves and mains in the water distribution system.

What does valve exercising help to do?

Valve exercising helps to prevent seizing of valves in the water system.

What is the equivalent of 1 cubic foot of water in gallons?

1 cubic foot of water equals 7.48 gallons.

What is the lbs/day formula?

The lbs/day formula includes flow multiplied by concentration multiplied by 8.34.

If flow is 2 MGD and chlorine is 2 mg/L, what is lbs/day?

If flow is 2 MGD and chlorine is 2 mg/L, lbs/day equals 33.36.

What is the detention time for a tank holding 100,000 gallons at 500 gpm?

The detention time at 500 gpm is 400 minutes.

What does a 10% chlorine solution contain?

A 10% chlorine solution contains 0.834 lb per gallon.

What does 8.34 represent?

8.34 represents pounds per gallon of water.

What is the filter area rate for a 100 sq ft filter with a flow of 200 gpm?

The rate is 2 gpm/ft².

If pH is too low, what should be added?

If pH is too low, lime should be added.

What should be done if chlorine residual is too high?

If chlorine residual is too high, reduce the dosage.

How many gpm are in 1 MGD?

1 MGD equals 694 gpm.

What is the radius of a circular tank with a diameter of 20 ft?

10 ft

How is the volume of a rectangular basin calculated?

The volume of a rectangular basin equals length multiplied by width multiplied by depth.

What happens to detention time if flow doubles?

If flow doubles, detention time will be cut in half.

How is chlorine demand calculated?

Chlorine demand equals dose minus residual.

What happens to filters if raw water turbidity is high?

If raw water turbidity is high, filters will clog faster.

What generally happens when increasing filter rate?

Increasing filter rate generally reduces water quality.

What does a higher CT value indicate?

A higher CT value means more effective disinfection.

How often should chemical feed pumps be calibrated?

Chemical feed pumps should be calibrated regularly.

What should be checked if pressure drops suddenly?

If pressure drops suddenly, check for a line break.

What does a 500-gallon tank at 50% full contain?

A 500-gallon tank at 50% full contains 250 gallons.

What is the common weight of chlorine gas cylinders?

150 lbs.

What must be true for samples when sampling bacteria?

Samples must be sterile when sampling for bacteria.

What indicates filter breakthrough?

Increased turbidity indicates filter breakthrough.

What causes taste and odor in water?

Taste and odor in water can be caused by algae.

What removes algae from water?

Chlorination removes algae from water.

What is the best indicator of filter performance?

The best indicator of filter performance is turbidity.

What should be done first during an emergency?

The first action during an emergency should be to protect public health.

What is the most important duty of an operator?

The most important duty of an operator is to provide safe drinking water.