Class D Water License UPDATED SCRIPT 2026 PRACTICE SOLUTIONS GRADED A+

Class D Water License UPDATED SCRIPT
2026 PRACTICE SOLUTIONS GRADED A+

● Which minerals cause hardness in water?
A. Calcium and manganese
B. Nitrates and phosphates
C. Magnesium and calcium
D. Iron and magnesium. Answer: C. Magnesium and calcium


● The most important federal law impacting the water utility industry is
the _______.
A. Water Resources Development Act
B. Hazard Communication Act
C. Federal Water Pollution Control Act
D. Safe Drinking Water Act. Answer: D. Safe Drinking Water Act


● The four water quality standards established for drinking water in the
Safe Drinking Water Act are chemical, bacteriological, radiological, and
_______.
A. Mineral
B. Physical
C. Thermal

, D. Taste and odor
E. Organic/inorganic. Answer: B. Physical


● The minimum allowable pressure in the distribution system under
emergency conditions is ________.
A. 35psi
B. 20psi
C. 30pis
D. None listed. Answer: B. 20psi


● Water vapor given off by plants and trees is known as _______.
A. Precipitation
B. Transportation
C. Evaporation
D. Transpiration. Answer: D. Transpiration


● Organic matter includes _______.
A. Leaves, beavers, birds, clay
B. Wood, fish, algae, sand
C. Wood, dogs, algae, bacteria
D. Plants, animals, humans, minerals. Answer: C. Wood, dogs, algae,
bacteria