CALIFORNIA WATER DISTRIBUTION
GRADE 3 EXAM QUESTIONS WITH
100% CORRECT ANSWERS LATEST
VERSION 2025/2026.
R.P.P.A. - ANS Reduced pressure principal assembly.
Backflow prevention for back siphonage and back pressure.
American Public Works Association color codes. White,pink,red,yellow,orange, blue, purple and
green - ANS White=proposed excavation
Pink=temporary survey markings
red=electric power
yellow=gas,oil and steam
orange=communications(phone/cable)
blue=water
purple=reclaimed water
green=sewer and storm drains.
Distance between water and sewer lines. - ANS Running parallel-at least 10ft apart.
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
,Perpendicular crossing-water lines at least 1ft above sewer.
Common trench-water and sewer must not be in same trench.
Water main and force main regulations. - ANS Parallel-at least 10ft apart.
Perpendicular crossing-Water lines at least 1ft above and force main should be encased 10ft in
both directions.
New water lines installed over force mains should be rated to 200psi or equivalent.
Force mains over 1000ft must have clean outs every 600ft.
Fire extinguishers Class A, B, C, D and K - ANS A=ordinary combustibles. Wood, paper, cloth
trash and plastic.
B=Flammable liquids. Gasoline, petroleum oil and paint.
C=Energized electrical equipment. Motors, transformers and appliances.
D=Combustible metals. Potassium, sodium, aluminum and magnesium.
K=Cooking oils and grease.
Drawdown - ANS Difference between the static pumping level and the pumping water level.
Residual drawdown - ANS A lowered water level that remains for a period of time after
pumping has been stopped.
Cone of depression - ANS Depressed water surface around a well when pumps are operating.
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, What is Coliform Bacteria? - ANS A group of bacteria found in the intestines of warm blooded
animals. Also found in plants, soil, air and water. It's positive test is and indication that the water
is polluted and may contain pathogenic (disease causing) organisms. Most coliform bacteria are
not necessarily bad for you, but are used as an indicator to warn of more harmful bacteria.
Testing this way is the easiest, most efficient and least expensive way.
E. coli, however, is a type of coliform bacteria (fecal) that can make people sick.
4 types of corrosion - ANS Chemical: Low PH/ soft water
Electrical: Galvanic reaction of dissimilar metals where one erodes the other.
Erosion: Velocity greater than 5 feet per second erodes pipes and bends like sandpaper over
time. Also increases dissolved oxygen content in highly oxygenated water.
Biological: Living organisms-Iron bacteria and sulfate reducing bacteria. Common in ground
water.
What is corrosion? - ANS The gradual decomposition of a material over time by a chemical
action.
Tier 1 violations - ANS Directly and immediately affect public health.
-Fecal coliform positive.
-Nitrite, nitrate or total MCL violation.
-Chlorine Dioxide MRDL violation.
-Turbidity MCL violation.
3 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
GRADE 3 EXAM QUESTIONS WITH
100% CORRECT ANSWERS LATEST
VERSION 2025/2026.
R.P.P.A. - ANS Reduced pressure principal assembly.
Backflow prevention for back siphonage and back pressure.
American Public Works Association color codes. White,pink,red,yellow,orange, blue, purple and
green - ANS White=proposed excavation
Pink=temporary survey markings
red=electric power
yellow=gas,oil and steam
orange=communications(phone/cable)
blue=water
purple=reclaimed water
green=sewer and storm drains.
Distance between water and sewer lines. - ANS Running parallel-at least 10ft apart.
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
,Perpendicular crossing-water lines at least 1ft above sewer.
Common trench-water and sewer must not be in same trench.
Water main and force main regulations. - ANS Parallel-at least 10ft apart.
Perpendicular crossing-Water lines at least 1ft above and force main should be encased 10ft in
both directions.
New water lines installed over force mains should be rated to 200psi or equivalent.
Force mains over 1000ft must have clean outs every 600ft.
Fire extinguishers Class A, B, C, D and K - ANS A=ordinary combustibles. Wood, paper, cloth
trash and plastic.
B=Flammable liquids. Gasoline, petroleum oil and paint.
C=Energized electrical equipment. Motors, transformers and appliances.
D=Combustible metals. Potassium, sodium, aluminum and magnesium.
K=Cooking oils and grease.
Drawdown - ANS Difference between the static pumping level and the pumping water level.
Residual drawdown - ANS A lowered water level that remains for a period of time after
pumping has been stopped.
Cone of depression - ANS Depressed water surface around a well when pumps are operating.
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, What is Coliform Bacteria? - ANS A group of bacteria found in the intestines of warm blooded
animals. Also found in plants, soil, air and water. It's positive test is and indication that the water
is polluted and may contain pathogenic (disease causing) organisms. Most coliform bacteria are
not necessarily bad for you, but are used as an indicator to warn of more harmful bacteria.
Testing this way is the easiest, most efficient and least expensive way.
E. coli, however, is a type of coliform bacteria (fecal) that can make people sick.
4 types of corrosion - ANS Chemical: Low PH/ soft water
Electrical: Galvanic reaction of dissimilar metals where one erodes the other.
Erosion: Velocity greater than 5 feet per second erodes pipes and bends like sandpaper over
time. Also increases dissolved oxygen content in highly oxygenated water.
Biological: Living organisms-Iron bacteria and sulfate reducing bacteria. Common in ground
water.
What is corrosion? - ANS The gradual decomposition of a material over time by a chemical
action.
Tier 1 violations - ANS Directly and immediately affect public health.
-Fecal coliform positive.
-Nitrite, nitrate or total MCL violation.
-Chlorine Dioxide MRDL violation.
-Turbidity MCL violation.
3 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
