Texas TCEQ Class B Surface Water | 293+
Questions & Complete Detailed Solutions
(New 2026/2027 Update)
This TCEQ Class B Surface Water licensing exam is a comprehensive test
administered by the Texas Commission on Environmental Quality (TCEQ). It
covers advanced surface water treatment concepts, state regulations, chemistry,
and plant operations.
This "293 Questions & Answers" is an important study bank set collection. This
collection covers the core technical topics required to pass the exam.
Coagulation, Flocculation, & Jar Testing
Managing chemical dosing to remove particles is one of the most heavily tested
operations on the Class B exam.
• Crucial Coagulation Factors: Alkalinity and pH are the single most
significant parameters for establishing correct coagulant dosages.
• pH Targets for Metals: Iron oxidizes best at a pH range of 7.5 to 8.0,
while manganese requires a higher pH of 9.0 to 10.0.
• Lime & Soda Ash: Added to water to increase alkalinity, which
strengthens the forming floc and enhances particle settling.
• Filter Aids: Nonionic polymers are commonly utilized specifically as filter
aids to stop premature turbidity breakthrough.
• Jar Testing Limitations: While jar tests determine optimum chemical
and coagulant dosages, they cannot be used to calibrate physical
equipment like pumps or motors.
Filtration & Plant Operations
Operators must maintain standard hydraulic rates and mechanical structures to
prevent system failure.
1
, • Filtration Rates: Under standard operating conditions, a rapid sand filter
flows at 2 to 4 GPM/ft².
• Backwash Rates: During a backwash cycle, the required backwash rate
spikes to 16 GPM/ft².
• Backwash Triggers: Rapid sand filters must be backwashed when they
reach a 100-hour run time or hit 6 to 10 feet of head loss.
• Mud Ball Hazards: Formation of mud balls within the filter media causes
channeling of water and premature turbidity breakthrough.
Disinfection & Chlorine Safety
Safe handling and chemical understanding of chlorine are critical components of
public water protection.
• Chlorine Chemistry: Free chlorine (\(Cl_{2}\)) reacts with water to form
hypochlorous acid (\(HOCl\)) and hydrochloric acid (\(HCl\)), with
hypochlorous acid (\(HOCl\)) being the stronger disinfectant.
• Prechlorination Purpose: Injected into raw inlet water to destroy bulk
bacteria, oxidize organics/metals, and control taste and odor.
• THM Formation: Chlorine reacts with natural organic matter (NOM)—
specifically humic and fulvic acids—to form harmful Trihalomethanes
(THMs).
• Gas Properties: Chlorine gas is greenish-yellow and 2.5 times heavier
than air.
• Room Ventilation: Chlorine cylinder rooms containing more than one
150-pound cylinder must feature high-level intake fans and low floor
vents.
TCEQ Regulations & Reporting
Texas state mandates dictate specific recording intervals, compliance levels, and
main maintenance.
• Monthly Reporting: Systems must report pH, alkalinity, and turbidity
levels monthly to the TCEQ.
2
, • Turbidimeter Recordings: Filter effluent turbidimeters must
continuously record data every 15 minutes.
• Lead & Copper Action Levels: Under the Lead and Copper Rule, action
limits are strictly set at 0.015 mg/L for Lead and 1.3 mg/L for Copper.
• New Main Disinfection: Newly installed water mains must be disinfected
using a chlorine dosage of 50 mg/L for 24 hours or 500 mg/L for 30
minutes.
• Separation Distance: Water lines must maintain a minimum distance
from sewer lines, generally requiring a 9-foot separation or specific
pressure-rated pipe protections.
Quiz_________________?
Explain and expand on Chlorine Dioxide (what it reacts with, oxidizes, etc) -
Answer
Chlorine Dioxide is a gas used in small quantities to disinfect water. It does not
react with organics to form THMs and HAAs. It oxidizes phenols, manganese,
iron, sulfurous and organic compounds which aids in the removal of tastes and
odors. It is a very effective bactericide and a superior virocide. It dies not
combine with ammonia. Chlorine Dioxide MRDL is .8 mg/L and monitoring
procedures are the same as for chlorine. The Chlorite MCL is .q mg/L and must
be monitored daily.
Quiz_________________?
What is texas drinking water pH requirements? -
Answer
3
, The texas drinking water requirements require a pH > 7.0 for the water
treatment plant finished water. EPA requires that pH analysis be preformed within
15 minutes of the sample being caught.
Quiz_________________?
How does pH affect Chlorine activity? -
Answer
When chlorine is added to water it forms hypochlorous acid (HOCL) and
hydrochloric acid (OCL). The hypochlorous acid is the effective disinfectant. At a
pH of 4.0 there is 100% hypochlorous acid. At a pH of 11 there is 100%
hypochlorite ion. At a pH of 7, the hypochlorous acid is at about 80% and the
hypochlorite ion makes up about 20% of the chlorine content. The lower the pH
is more effective chlorine is because you have more hypochlorous acid.
Quiz_________________?
What is meant by water stability? -
Answer
Stable water is defined as water that will neither deposit or dissolve a calcium
carbonate film or scale. Since no water is stable indefinitely, chemical treatment of
water usually is intended to produce water that is slightly scale forming without
being liable to cause stoppages in small lines and services. Bayliss curve is the
simplest determination of stability. The Langelier saturation index is also used.
Quiz_________________?
What/how are above ground tanks and piping protected from corrosion? -
4
Questions & Complete Detailed Solutions
(New 2026/2027 Update)
This TCEQ Class B Surface Water licensing exam is a comprehensive test
administered by the Texas Commission on Environmental Quality (TCEQ). It
covers advanced surface water treatment concepts, state regulations, chemistry,
and plant operations.
This "293 Questions & Answers" is an important study bank set collection. This
collection covers the core technical topics required to pass the exam.
Coagulation, Flocculation, & Jar Testing
Managing chemical dosing to remove particles is one of the most heavily tested
operations on the Class B exam.
• Crucial Coagulation Factors: Alkalinity and pH are the single most
significant parameters for establishing correct coagulant dosages.
• pH Targets for Metals: Iron oxidizes best at a pH range of 7.5 to 8.0,
while manganese requires a higher pH of 9.0 to 10.0.
• Lime & Soda Ash: Added to water to increase alkalinity, which
strengthens the forming floc and enhances particle settling.
• Filter Aids: Nonionic polymers are commonly utilized specifically as filter
aids to stop premature turbidity breakthrough.
• Jar Testing Limitations: While jar tests determine optimum chemical
and coagulant dosages, they cannot be used to calibrate physical
equipment like pumps or motors.
Filtration & Plant Operations
Operators must maintain standard hydraulic rates and mechanical structures to
prevent system failure.
1
, • Filtration Rates: Under standard operating conditions, a rapid sand filter
flows at 2 to 4 GPM/ft².
• Backwash Rates: During a backwash cycle, the required backwash rate
spikes to 16 GPM/ft².
• Backwash Triggers: Rapid sand filters must be backwashed when they
reach a 100-hour run time or hit 6 to 10 feet of head loss.
• Mud Ball Hazards: Formation of mud balls within the filter media causes
channeling of water and premature turbidity breakthrough.
Disinfection & Chlorine Safety
Safe handling and chemical understanding of chlorine are critical components of
public water protection.
• Chlorine Chemistry: Free chlorine (\(Cl_{2}\)) reacts with water to form
hypochlorous acid (\(HOCl\)) and hydrochloric acid (\(HCl\)), with
hypochlorous acid (\(HOCl\)) being the stronger disinfectant.
• Prechlorination Purpose: Injected into raw inlet water to destroy bulk
bacteria, oxidize organics/metals, and control taste and odor.
• THM Formation: Chlorine reacts with natural organic matter (NOM)—
specifically humic and fulvic acids—to form harmful Trihalomethanes
(THMs).
• Gas Properties: Chlorine gas is greenish-yellow and 2.5 times heavier
than air.
• Room Ventilation: Chlorine cylinder rooms containing more than one
150-pound cylinder must feature high-level intake fans and low floor
vents.
TCEQ Regulations & Reporting
Texas state mandates dictate specific recording intervals, compliance levels, and
main maintenance.
• Monthly Reporting: Systems must report pH, alkalinity, and turbidity
levels monthly to the TCEQ.
2
, • Turbidimeter Recordings: Filter effluent turbidimeters must
continuously record data every 15 minutes.
• Lead & Copper Action Levels: Under the Lead and Copper Rule, action
limits are strictly set at 0.015 mg/L for Lead and 1.3 mg/L for Copper.
• New Main Disinfection: Newly installed water mains must be disinfected
using a chlorine dosage of 50 mg/L for 24 hours or 500 mg/L for 30
minutes.
• Separation Distance: Water lines must maintain a minimum distance
from sewer lines, generally requiring a 9-foot separation or specific
pressure-rated pipe protections.
Quiz_________________?
Explain and expand on Chlorine Dioxide (what it reacts with, oxidizes, etc) -
Answer
Chlorine Dioxide is a gas used in small quantities to disinfect water. It does not
react with organics to form THMs and HAAs. It oxidizes phenols, manganese,
iron, sulfurous and organic compounds which aids in the removal of tastes and
odors. It is a very effective bactericide and a superior virocide. It dies not
combine with ammonia. Chlorine Dioxide MRDL is .8 mg/L and monitoring
procedures are the same as for chlorine. The Chlorite MCL is .q mg/L and must
be monitored daily.
Quiz_________________?
What is texas drinking water pH requirements? -
Answer
3
, The texas drinking water requirements require a pH > 7.0 for the water
treatment plant finished water. EPA requires that pH analysis be preformed within
15 minutes of the sample being caught.
Quiz_________________?
How does pH affect Chlorine activity? -
Answer
When chlorine is added to water it forms hypochlorous acid (HOCL) and
hydrochloric acid (OCL). The hypochlorous acid is the effective disinfectant. At a
pH of 4.0 there is 100% hypochlorous acid. At a pH of 11 there is 100%
hypochlorite ion. At a pH of 7, the hypochlorous acid is at about 80% and the
hypochlorite ion makes up about 20% of the chlorine content. The lower the pH
is more effective chlorine is because you have more hypochlorous acid.
Quiz_________________?
What is meant by water stability? -
Answer
Stable water is defined as water that will neither deposit or dissolve a calcium
carbonate film or scale. Since no water is stable indefinitely, chemical treatment of
water usually is intended to produce water that is slightly scale forming without
being liable to cause stoppages in small lines and services. Bayliss curve is the
simplest determination of stability. The Langelier saturation index is also used.
Quiz_________________?
What/how are above ground tanks and piping protected from corrosion? -
4
