TEXAS WASTEWATER CLASS D NEWEST ACTUAL EXAM COMPLETE 300 QESTIONS AND CORRECT DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY GRADED A+

1 | P a g e TEXAS WASTEWATER CLASS D NEWEST 2024-2025 ACTUAL EXAM COMPLETE 300 QESTIONS AND CORRECT DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY GRADED A+ One of the most important purposes of a public water supply is _______. a. swimming b. landscape watering c. car washing d. firefighting - ANSWER- d. firefighting Organic matter includes ________. a. sand b. plants, animals and humans c. minerals d. all listed - ANSWER- b. plants, animals and humans The most important treatment process is ________, which destroys disease-causing organisms. a. filtration b. disinfection 2 | P a g e c. softening d. fluoridation - ANSWER- b. disinfection Public water systems are required to compile a monthly report showing ________. a. rate increases b. accidents c. dates of dead-end flushing d. disciplinary action - ANSWER- c. dates of dead-end flushing Most groundwater is relatively free of suspended matter, but ________ can be a major problem in surface water. - ANSWERturbidity Color in a public water supply should be less than _____ units. - ANSWER- less than 15 units Chemical characteristics of water include hardness, pH, solids, and ________. - ANSWER- gases Water is considered hard when it exceeds ________ mg/L of calcium carbonate. - ANSWER- 100 (may vary depending on who you talk to) 3 | P a g e A gallon of water weighs _____ pounds and 1 mg/L equals one ________. - ANSWER- water weights 8.34 pounds 1 mg/L equals one part per million Hydrogen sulfide is heavier than air, colorless, flammable, toxic, and has a ________ odor. - ANSWER- rotten egg (unless you get a dose that's so heavy it numbs your sense of smell) Excessive nitrates in drinking water can cause ________ syndrome in infants. - ANSWER- blue baby syndrome Excessive amounts of fluoride may cause ________ or staining of teeth. - ANSWER- mottling Trihalomethanes and haloacetic acids are byproducts of chlorination and may increase ________ risk. - ANSWERcancer The action level for copper is _____ mg/L and for lead it is _____ mg/L. - ANSWER- copper is 1.3 mg/L lead is 0.015 mg/L 4 | P a g e _____ are underground, water-bearing formations yielding useful quantities of water. - ANSWER- Aquifers The quantity of water a formation yields depends on the thickness and _____ of the formation. - ANSWER- permeability Problems caused by _____ are declining water levels and subsidence. - ANSWER- overpumping Well _____ and cementing protect the well from collapse and surface contamination. - ANSWER- Well casing The purpose of the well screen is to keep out birds and insects. (true/false) - ANSWER- false (the well screen keeps out sand; the well vent screen keeps out birds and insects) The most important feature of the well screen is the length. (true/false) - ANSWER- false (the mesh size is the most important feature) The _____ of the screen is determined by the size of the aquifer material, the size of the gravel in the gravel pack, and the type of well development. - ANSWER- mesh size