TCEQ A PREP QUESTIONS AND ANSWERS
New Surface water reservoirs in Texas? - Answers - declines in certain areas.
Sequestering manganese question? - Answers - Does not allow manganese to combine
with oxygen.
Lead % in pipe and solder and flux? - Answers - Max lead is 0.25%, lead and solder flux
0.2%
Action level for Lead? - Answers - Lead action level is .015%
How do you know you have a TTHM MCL violation? - Answers - Locational running
average of all samples exceeds TTHM maximum contaminant level is .080.
NOTE: Pick the one that says LOCATIONAL and 0.080
TTHM averages 0.060, 0.080, 0.080 and 0.090. Add together and multiply time x4.
What has occurred? - Answers - The avg. does not exceed 0.080 so this is not a MCL
violation. This is an operational level violation and an operational assessment will need
to be performed.
Groundwater system has 2 pressure planes with 100 connections each. How many
pumps, and the GPM is required? - Answers - Must have 2 or more pumps per pressure
plane or pump station @ 0.2gpm total capacity.
4 pumps, 200gpm
What is a bolson aquifer? - Answers - Deep filled valley deposits
A Chloraminated system is purchased with 1mg/l total chlorine and 0.1mg/l free
ammonia. What booster dosage do you have to apply to reach a 2.5mg/l total residual?
- Answers - The ratio is 5 parts chlorine to 1 part ammonia. My math came out to
answer A but you may double check.
A. 0.2mg/L ammonia first, then 1.5mg/l chlorine
What happens when excess chlorine is added? - Answers - The total residual becomes
unstable
If groundwater with 1mg/L of free chlorine is blended with surface water with 1mg/L
monochloramine and 05mg/L free ammonia, what happens? - Answers - Free ammonia
will mix with free chlorine and create dicholramine that can cause taste and odor issues.
When to backwash a pressure filter? - Answers - When it reaches 10psi of head loss
Who controls groundwater in the state of Texas? - Answers - Groundwater is private
property
, Hypoliminion aeration does what? - Answers - Adds oxygen to the bottom layer
When total hardness equals total alkalinity? - Answers - The hardness is all carbonate
Permanent hardness question? - Answers - Permanent hardness cannot be removed
with the use of chemicals
A 20' diameter tank, 19ft deep. Flow is .013MGD. How many hours will it take to fill the
tank 2 times? - Answers - 3.14x10x10x19 =5966
5966x7.48(1 cubic foot of water)= 44,625.68 gallons
.013x1440 to get gallons per min =18.72 gallons per min
44,625.68/18.72=2383.8 min=39.7 hours
What do you need to determine a chlorine dosage? - Answers - Amount of chemical and
volume of water to be treated
65' x 20' x 12' sedimentation basin. Flow is 1,600,000 gallons per day. What is detention
time? - Answers - 1.8 hours
convert 1,600,000 gpd to gph 1,600, = 66,667 gph
dention time = voulme of tank in gallons / flow rate
65x20x12x7.,667= 1.8 hours
Mud ball percent volume math. 695 ml total sample. Water begins at 500ml and rises to
545ml. What is the percent volume? - Answers - 542ml-500ml = 42ml difference;
42ml/695ml x 100 = 6%
Maximum gpm for granular filter media? - Answers - 2gpm/ft
Well has 150' airline. Pressure gauge reads 43psi when off and 30psi when pumping.
What is the drawdown? - Answers - Drawdown = static level - pumping level; 43psi x
2.31 = 99, 30 x 2.31 = 69. 99-69 = 30' of drawdown
Well pumps 250 gpm for 24 hours. The question gives a static psi reading and a
pumping psi reading. Find the specific capacity of the well? - Answers - Do the math to
find the drawdown first (psi x 2.31) then (static level - pumping level). Then, pumping
rate (gpm)/drawdown = Specific Capacity.
Hydrostatic leakage question? - Answers - The answer is 1.5 times the working
pressure for 2 hours
These are all acute violations EXCEPT? - Answers - A positive total coliform sample is
the answer as it is not a MCL violation.
What is a membrane filter used for in a water lab? - Answers - Coliform organisms
New Surface water reservoirs in Texas? - Answers - declines in certain areas.
Sequestering manganese question? - Answers - Does not allow manganese to combine
with oxygen.
Lead % in pipe and solder and flux? - Answers - Max lead is 0.25%, lead and solder flux
0.2%
Action level for Lead? - Answers - Lead action level is .015%
How do you know you have a TTHM MCL violation? - Answers - Locational running
average of all samples exceeds TTHM maximum contaminant level is .080.
NOTE: Pick the one that says LOCATIONAL and 0.080
TTHM averages 0.060, 0.080, 0.080 and 0.090. Add together and multiply time x4.
What has occurred? - Answers - The avg. does not exceed 0.080 so this is not a MCL
violation. This is an operational level violation and an operational assessment will need
to be performed.
Groundwater system has 2 pressure planes with 100 connections each. How many
pumps, and the GPM is required? - Answers - Must have 2 or more pumps per pressure
plane or pump station @ 0.2gpm total capacity.
4 pumps, 200gpm
What is a bolson aquifer? - Answers - Deep filled valley deposits
A Chloraminated system is purchased with 1mg/l total chlorine and 0.1mg/l free
ammonia. What booster dosage do you have to apply to reach a 2.5mg/l total residual?
- Answers - The ratio is 5 parts chlorine to 1 part ammonia. My math came out to
answer A but you may double check.
A. 0.2mg/L ammonia first, then 1.5mg/l chlorine
What happens when excess chlorine is added? - Answers - The total residual becomes
unstable
If groundwater with 1mg/L of free chlorine is blended with surface water with 1mg/L
monochloramine and 05mg/L free ammonia, what happens? - Answers - Free ammonia
will mix with free chlorine and create dicholramine that can cause taste and odor issues.
When to backwash a pressure filter? - Answers - When it reaches 10psi of head loss
Who controls groundwater in the state of Texas? - Answers - Groundwater is private
property
, Hypoliminion aeration does what? - Answers - Adds oxygen to the bottom layer
When total hardness equals total alkalinity? - Answers - The hardness is all carbonate
Permanent hardness question? - Answers - Permanent hardness cannot be removed
with the use of chemicals
A 20' diameter tank, 19ft deep. Flow is .013MGD. How many hours will it take to fill the
tank 2 times? - Answers - 3.14x10x10x19 =5966
5966x7.48(1 cubic foot of water)= 44,625.68 gallons
.013x1440 to get gallons per min =18.72 gallons per min
44,625.68/18.72=2383.8 min=39.7 hours
What do you need to determine a chlorine dosage? - Answers - Amount of chemical and
volume of water to be treated
65' x 20' x 12' sedimentation basin. Flow is 1,600,000 gallons per day. What is detention
time? - Answers - 1.8 hours
convert 1,600,000 gpd to gph 1,600, = 66,667 gph
dention time = voulme of tank in gallons / flow rate
65x20x12x7.,667= 1.8 hours
Mud ball percent volume math. 695 ml total sample. Water begins at 500ml and rises to
545ml. What is the percent volume? - Answers - 542ml-500ml = 42ml difference;
42ml/695ml x 100 = 6%
Maximum gpm for granular filter media? - Answers - 2gpm/ft
Well has 150' airline. Pressure gauge reads 43psi when off and 30psi when pumping.
What is the drawdown? - Answers - Drawdown = static level - pumping level; 43psi x
2.31 = 99, 30 x 2.31 = 69. 99-69 = 30' of drawdown
Well pumps 250 gpm for 24 hours. The question gives a static psi reading and a
pumping psi reading. Find the specific capacity of the well? - Answers - Do the math to
find the drawdown first (psi x 2.31) then (static level - pumping level). Then, pumping
rate (gpm)/drawdown = Specific Capacity.
Hydrostatic leakage question? - Answers - The answer is 1.5 times the working
pressure for 2 hours
These are all acute violations EXCEPT? - Answers - A positive total coliform sample is
the answer as it is not a MCL violation.
What is a membrane filter used for in a water lab? - Answers - Coliform organisms
