Class D Basic Water Practice Test
questions with correct answers
A trench 24in wide 800ft long and 4ft deep is to be excavated. The amount of soil excavated is? -
ANSWER: ➡ 6400ft
An elevated storage tank had pipe 150 feet above ground when full water pressure at the bottom psi
should be? - ANSWER: ➡ 65
Chlorine dosage for water is 2.7mg/l if chlorine residual after 30 minutes is 0.8mg/l. What is demand
expressed in mg/l? - ANSWER: ➡ 1.9
Water is pumped 250 gallons a min. How long to fill 100,000 gallon tank? - ANSWER: ➡ 6.6
A free chlorine residual of 0.6mg/l is desired how many mg/l of chlorine will be needed when
chlorine demand of water is 2.2mn/l? - ANSWER: ➡ 1.6
A chlorine dosage of 2mg/l is to be added to 600,000 gallons of water how many pounds of chlorine
100% are needed to obtain this concentration? - ANSWER: ➡ 10
The hydrologic cycle is? - ANSWER: ➡ Recycling of water between the earth & atmosphere
Basic water PH reading is? - ANSWER: ➡ 8.5
A chemical of water impacting scaling is? - ANSWER: ➡ Calcium
What is Raw water? - ANSWER: ➡ Untreated water
, Regulated chemical compound formed when disinfectants react with naturally occurring organic
matter? - ANSWER: ➡ By products THM/HAA
Diseases by contaminated water also known as waterborn disease are? - ANSWER: ➡ Dysentery,
Hyphoid, Giardiasis, Hepatitis
A fire and explosion exsist if granulated disinfectant, calcium hydrochlorite come in contact with? -
ANSWER: ➡ Oil petro products
Following Lock Out Tag Out (LOTO) the first step a oparater should take to restart pump after
emergency repairs are performed? - ANSWER: ➡ Call the person who owns or put the locks on
The Texas hazard communication act 1985 requires employers to? - ANSWER: ➡ Provide info on
Haz Chem in the work place.
A flagger for traffic control - ANSWER: ➡ TxDoT
When storing gas chlorine cylinders the containment room should include both high level fresh
intake fan and floor exhaust vent because chlorine is? - ANSWER: ➡ Heavy then Air
Shoring takes place when trench is more than? - ANSWER: ➡ +5ft
TCEQ requires a combined filter effluent turbity of 0.3 or less in at least 95% of measurements taken
each month? - ANSWER: ➡ 0.3
A boil water notice for? - ANSWER: ➡ In the event of low water pressure <20psi. Water outage,
ECell
For public water systems with more than 250 connections chlorine residual testing must be
performed at least once a? - ANSWER: ➡ Day (disinfection)
questions with correct answers
A trench 24in wide 800ft long and 4ft deep is to be excavated. The amount of soil excavated is? -
ANSWER: ➡ 6400ft
An elevated storage tank had pipe 150 feet above ground when full water pressure at the bottom psi
should be? - ANSWER: ➡ 65
Chlorine dosage for water is 2.7mg/l if chlorine residual after 30 minutes is 0.8mg/l. What is demand
expressed in mg/l? - ANSWER: ➡ 1.9
Water is pumped 250 gallons a min. How long to fill 100,000 gallon tank? - ANSWER: ➡ 6.6
A free chlorine residual of 0.6mg/l is desired how many mg/l of chlorine will be needed when
chlorine demand of water is 2.2mn/l? - ANSWER: ➡ 1.6
A chlorine dosage of 2mg/l is to be added to 600,000 gallons of water how many pounds of chlorine
100% are needed to obtain this concentration? - ANSWER: ➡ 10
The hydrologic cycle is? - ANSWER: ➡ Recycling of water between the earth & atmosphere
Basic water PH reading is? - ANSWER: ➡ 8.5
A chemical of water impacting scaling is? - ANSWER: ➡ Calcium
What is Raw water? - ANSWER: ➡ Untreated water
, Regulated chemical compound formed when disinfectants react with naturally occurring organic
matter? - ANSWER: ➡ By products THM/HAA
Diseases by contaminated water also known as waterborn disease are? - ANSWER: ➡ Dysentery,
Hyphoid, Giardiasis, Hepatitis
A fire and explosion exsist if granulated disinfectant, calcium hydrochlorite come in contact with? -
ANSWER: ➡ Oil petro products
Following Lock Out Tag Out (LOTO) the first step a oparater should take to restart pump after
emergency repairs are performed? - ANSWER: ➡ Call the person who owns or put the locks on
The Texas hazard communication act 1985 requires employers to? - ANSWER: ➡ Provide info on
Haz Chem in the work place.
A flagger for traffic control - ANSWER: ➡ TxDoT
When storing gas chlorine cylinders the containment room should include both high level fresh
intake fan and floor exhaust vent because chlorine is? - ANSWER: ➡ Heavy then Air
Shoring takes place when trench is more than? - ANSWER: ➡ +5ft
TCEQ requires a combined filter effluent turbity of 0.3 or less in at least 95% of measurements taken
each month? - ANSWER: ➡ 0.3
A boil water notice for? - ANSWER: ➡ In the event of low water pressure <20psi. Water outage,
ECell
For public water systems with more than 250 connections chlorine residual testing must be
performed at least once a? - ANSWER: ➡ Day (disinfection)
