Class D Water Operator License Exam Questions and Answers Latest 2024/2025 | 100% Correct | Graded A+

In Texas, about 75% of all water is used for commercial, industrial, or agricultural purposes. (Ans- True Water covers approximately ________ of Earth's surface. (Ans- 71% Drought is an extended period when a region receives a deficiency in its ________ water supply. (Ans- atmospheric, ground, or surface T/F: Only about 1 gallon of tap water per person/day is used for drinking and cooking (Ans- True Excluding outside water use, the average household uses about _______ gallons of water per month for inside use (Ans- 2,000 T/F: Only 3% of all the fresh water on earth can be easily accessed for use. (Ans- False (only 1%) T/F: In 1978, the Texas Department of Health (TDH) assumed primacy over the Safe Drinking Water Act from the EPA. (Ans- True T/F: PWS officials should be pro-active in their approach to terrorism. (Ans- True TCEQ Class D Water Operator License Exam Questions and Answers Latest 2024/2025 | 100% Correct | Graded A+ _________ permits the owner of a well to pump as much water as desired, even if the water is drained from beneath the land of others. (Ans- Rule of Capture In Texas, agricultural water demand accounts for about ___% of the total water used. (Ans- 57% T/F: An example of a non-transient non-community PWS is a rural school. (Ans- True Monitoring average and maximum daily water ______ enables us to plan ahead for growth. (Ans- Demand T/F: The Safe Drinking Water Act sets standards for drinking water including physical, chemical, bacteriological, and radiological characteristics. (Ans- True "Potable" means water is safe to drink and has a measurable chlorine ________. (Ans- Residual The plant operator is responsible for a sufficient supply of safe and ________ drinking water. (Ans- Palatable T/F: The Texas State Board of Fire Insurance requires utilities that provide fire protection to have a minimum amount of water available based on 30 gals per person per day. (Ans- False (130 gals per person per day) T/F: The primary state regulator of water utilities is the TCEQ. (Ans- True T/F: All community and non-transient non-community PWS, regardless of source of water, must be under the supervision of a licensed water works operator. (Ans- True Meter readers bring in operating revenue and profoundly impact _____ relations. (Ans- Public The federal regulator of drinking water is the _____. (Ans- EPA T/F: Duties of distribution operator include repairing leaks, making taps, flushing mains, and taking radiological samples. (Ans- False (Repair leaks, Make taps, Flush mains, Operate pumps, Take *bacteriological* samples) A service area has 1000 service connections. What can we estimate the population of this service area to be? (Ans- 3,000 (multiply connections x 3) T/F: The State must be notified after an existing facility is changed or after construction of a new facility. (Ans- False (must notify *before*) T/F: A Class "D" license is valid for 2 years at ground and purchase water systems with 250 connections or less. (Ans- False (3 years) T/F: The physical characteristics of water are color, taste, odor, temperature, and turbidity. (Ans- True An alkaline or basic solution has a pH greater than ____. (Ans- 7 T/F: The terms mg/L and ppm are not interchangeable. (Ans- False (they are interchangeable) Suspended solids in water cannot be filtered out. (Ans- False (they can) Solids, water hardness, pH and gases are ____ characteristics. (Ans- Chemical T/F: There are 2 hydrogen atoms and 1 oxygen atom in each water molecule. (Ans- True T/F: The State recommends a water pH of less than 7 to be maintained at all time. (Ans- False (The state recommends a pH slightly greater than 7 and for the water to be non-corrosive.) T/F: Taste and odor can come from organisms such as vegetation, bacteria, and algae, and from certain chemicals and metals. (Ans- True T/F: The deeper the well, the warmer the water. (Ans- True T/F: The threshold odor number (TON) relates to the number of dilutions needed for the water to be tasteless. (Ans- False (It reflects the number of dilutions needed for water sample to be *odorless*) One part per million or 1 mg/L means that for every ____ pounds of water there is one pound of material in it. (Ans- 1 million The State requires filtered water to be equal to or less than ____ turbidity units in at least 95% of the monthly samples. (Ans- 0.3 The State recommends a TON of ___ or less. (Ans- 3 T/F: The State recommends 20 color units or less for a quality water. (Ans- False (The state recommends 15 units of color or less for drinking water.) T/F: Examples of inorganic matter found in water include rock, sand, metals, and minerals. (Ans- True T/F: The red color caused by iron is an example of suspended or apparent color and it can be removed by filtration. (Ans- True Excessive calcium and _____ are the primary cause of hardness in water. (Ans- Magnesium T/F: The State recommends a maximum total dissolved solids content of 500 mg/L (Ans- False (The state recommends that TDS not exceed 1000 mg/L) There are 3 common gases found in water: methane, carbon dioxide, and __________ ___________. (Ans- hydrogen sulfide T/F: Turbidity must be limited because it shelters and nourishes bacteria and interferes with disinfection. (Ans- True T/F: Bleach or alcohol require less contact time than flaming to disinfect a faucet. (Ans- False (flaming requires less contact time) T/F: The "primary limits" refer to chemicals with maximum contaminant levels that can be exceeded. (Ans- False (refers to chemicals with maximum contaminant levels (MCLs) that *CANNOT* be exceeded.) T/F: The term "total coliform" means fecal and non-fecal coliform. (Ans- True T/F: Pathogens are disease-causing microorganisms. (Ans- True If a routine sample is positive, flush the positive sample point, check the chlorine residual, then resample within 24 days of notification. (Ans- False (If a routine sample is total coliform-positive, the PWS should flush the positive sample point, check the chlorine residual, then resample within *24 hrs* of notification) To prevent the formation of THMS in surface water, chlorine is combined with _____ forming chloramine, combined chlorine residual. (Ans- Ammonia If there is no chlorine ______ at a faucet, do not sample, flush longer. (Ans- residual T/F: All repeat samples must be collected on successive days. (Ans- False (Collect all repeat sample on the same day) In the event of distribution pressure below ___ psi, _______ outages, repeated bad samples or chlorine _____ below minimum, special precautions must be instituted. (Ans- 20/water/residual Get the sample to the lab within ___________ or it will be rejected. (Ans- 30 hours (for BacT samples) At 0.8 - 1.0 mg/L, fluoride reduces dental cavities, but in higher doeses (>2.0 mg/L) can cause _____ of teeth over time. (Ans- mottling T/F: One by-product of chlorinated drinking water is trihalomethane, a suspected carcinogen. (Ans- True Repeat samples must be taken at (a) the _______ ______ (b) within 5 connections upstream and (c) within 5 connections downstream. (Anspositive point T/F: If you do not fill out the submission form completely, you risk losing credit for the sample. (Ans- True T/F: The presence of fecal coliform in a water sample indicates fecal contamination from a human or warm-blooded animal. (Ans- True The purpose of the sample site plan is to assure bacteriological samples are collected from ______ service connections which are representative of the distribution system. (Ans- active T/F: Keep the sample in ice or in a cooler prior to and during lab transport because heat stimulates bacterial growth. (Ans- True The action level for lead is _______ mg/L and for copper it is _____ mg/L. (Ans- .015 / 1.3 T/F: Low doses of heavy metals such as lead and copper can cause damage to the central nervous system over time. (Ans- True A certain group of bacteria is used to indicate the possible presence of a pathogen--- the ________ group. (Ans- Coliform Disinfection is the destruction of disease-causing microorganisms called ______. (Ans- Pathogens At room temperature chlorine is a greenish-yellow gas that is ___ times heavier than air. (Ans- 2.5 The State requires ________ to be kept in stock for disinfecting new water lines. (Ans- Calcium hypochlorite T/F: Hypochlorinators consist of a mixing tank and chemical solution feed pump. (Ans- True A full-face self-contained breathing apparatus or supplied air respirator must be readily accessible outside the fire station when chlorine gas is used. (Ans- False (A full-face self-contained breathing apparatus (SCBA) or supplied air respirator that meets OSHA standards shall be readily accessible outside the *chlorinator room* when chlorine gas is used.) T/F: All public water systems must have chlorination facilities. (Ans- True If chlorine enters the eyes, flush with running cool water for at least ___ minutes and seek medical attention. (Ans- 15 minutes Liquid bleach used in PWS must be ______ approved. (Ans- NSF T/F: Primary components of a gas feed chlorinator include an injector, flowrate controller, rotameter, and mixing tank. (Ans- False (injector, vacuum regulator, flowrate controller, rotameter- *not a mixing tank*) The maximum sustained gas withdrawal rate for pressure transmission 150 lb cylinders is ____ lbs/day (Ans- 40 T/F: Utility operators use chlorine in three commercial forms: 1) pure chlorine in the liquid or gas state 2) bleach solutions 3) granular/tablet compounds (Ans- True T/F: If chlorine contacts the skin, flush with an emergency shower or garden hose for at least an hour. (Ans- False (15 minutes) Hypochlorous acid is the disinfectant and the _____ residual. (Ans- Free If a major chlorine leak occurs, call the supplier and ______. (Ans- TCEQ The rotameter indicates the feed rate in _____ per day (Ans- pounds T/F: Chlorine reacts with hydrocarbons producing heat or fire (Ans- True Chlorinator rooms must be provided with facilities from determining the amount of disinfectant used _______ (Ans- daily T/F: Dosage is the amount of chlorine applied in milligrams per liter or parts per billion. (Ans- False (parts per million)