TCEQ CLASS C WATER QUESTIONS AND ANSWERS GRADED
A++
✔✔According to the lead and copper rule. pipe and fittings may not contain more than
______ lead or solder and flux may not contain more than 0.2% lead. - ✔✔8.0%
✔✔After disinfection and flushing of a super chlorinated new lines and services but prior
to placing the line into service, bacteriological samples are required. The current
standard is ___________ sample for every ________ feet of line. - ✔✔One sample for
every 1000ft of line
✔✔Federal and state laws mandate bacteriological analyses of the water supply. These
samples must be obtained every_____? - ✔✔month
✔✔When doing a tap on soft or brittle water main, how should you make the tap? -
✔✔use a tap and clamp/ tap and saddle
✔✔What does gpm stand for? - ✔✔Gallons per minute
✔✔The purpose of a thrust block is ________________? - ✔✔Prevent movement at the
pipe joints.
✔✔Where is the corporation stop located? - ✔✔On the water main.
✔✔What is it called when the water goes in reverse caused by a vaccuum - ✔✔Back
Siphonage
✔✔The volume of a cylinder with a radius of 5ft and a height of 8ft is __________ft^3 -
✔✔3.14 x 5ft x 5ft x 8ft= 528ft^3
✔✔The volume of a 100ft diameter tank that is 12ft deep is ______ft^3 - ✔✔3.14 x 50ft
x 50ft x 12ft= 94,200ft^3
✔✔What is a volume of a settling tank 100ft long, 25ft wide, and 8ft deep? - ✔✔100ft x
25ft x 8ft = 20,000ft^3
✔✔A water treatment plant receives an average flow of 261 gallons per minute, what is
the daily flow to the plant? - ✔✔261gpm x 60 x 24 = 375,840gallons per day (round up)
380,000 but convert to MGD (gpm/1,000,000) = .38 mgd
✔✔What is the approximate volume in gallons occupied by 15,000ft^3 of water? -
✔✔15,000ft^3 x 7.48 gallons = 112,200 gallons
, ✔✔What is the approximate weight in pounds of 50,000 gallons of water? - ✔✔One
gallon of water weighs 8.34lbs
50,000 x 8.34 = 417,000
✔✔The flow in 35,000 gallons per day. What is that in MGD? - ✔✔.035MGD
✔✔What does one cubic foot of water weigh? - ✔✔7.48gal x 8.34lbs = 62.4lbs
✔✔If the pressure gauge at the bottom of a 200ft standpipe reads 68psi what is the
static head in feet? - ✔✔1psi = 2.31ft of elevation
68psi x 2.31ft x= 157ft
✔✔What is the chlorine demand if the residual is 0.6mg/L and 6.6mg/L has been
applied(dosage)? - ✔✔Demand = dosage - residual
6.6mg/L - .06mg/L = 6.0mg/L
✔✔How many gallons per minute is a flow of 1.0MGD - ✔✔MGD / = gallons per
min
1,000,000 gallons / = 695gpm
✔✔You have an 8'' pipe that is a 2500' long and you want to dose 50mg/L. How many
lbs of cl2 would you need? - ✔✔First find the volume of the pipe
3.14 x .33ft x .33ft x 2500ft = 854.87ft^3
Then convert to gallons
7.48 gallons x 854.87ft^3 = 6,394 gallons
.006394 MGD
Then use the following formula to complete the problem
lbs = MGD x 8.34 x mg/L
.006394MGD x 8.34lbs x 50mg/L = 2.66lbs of CL2
✔✔Three and one half mile of 8in pipe - assuming the ditch is 2ft wide and 4ft deep-
how many cubic yards of soil will be displaced in this project? - ✔✔V= L x W x H
first convert 3.5 miles to feet so 3.5miles x 5280ft = 18,480ft
18,480ft x 2ft x 4ft = 147,840ft
1 cubic yard of water contains 27ft^3 of water
147,840ft^ft^3 = 5,475.55yds
✔✔Your next job task is the installation of three and one half miles of 8in pvc main lines.
the pipe will be supplied in 20ft sections. How many sections will you install? -
✔✔3.5miles x 5280ft = 18,480ft
18,480ft / 20ft = 924 sections of pipe
✔✔In a cubic foot of water there are __________ gallons. how many gallons are there
in 9 cubic feet of water? - ✔✔7.48 gal and 67.32 gal
A++
✔✔According to the lead and copper rule. pipe and fittings may not contain more than
______ lead or solder and flux may not contain more than 0.2% lead. - ✔✔8.0%
✔✔After disinfection and flushing of a super chlorinated new lines and services but prior
to placing the line into service, bacteriological samples are required. The current
standard is ___________ sample for every ________ feet of line. - ✔✔One sample for
every 1000ft of line
✔✔Federal and state laws mandate bacteriological analyses of the water supply. These
samples must be obtained every_____? - ✔✔month
✔✔When doing a tap on soft or brittle water main, how should you make the tap? -
✔✔use a tap and clamp/ tap and saddle
✔✔What does gpm stand for? - ✔✔Gallons per minute
✔✔The purpose of a thrust block is ________________? - ✔✔Prevent movement at the
pipe joints.
✔✔Where is the corporation stop located? - ✔✔On the water main.
✔✔What is it called when the water goes in reverse caused by a vaccuum - ✔✔Back
Siphonage
✔✔The volume of a cylinder with a radius of 5ft and a height of 8ft is __________ft^3 -
✔✔3.14 x 5ft x 5ft x 8ft= 528ft^3
✔✔The volume of a 100ft diameter tank that is 12ft deep is ______ft^3 - ✔✔3.14 x 50ft
x 50ft x 12ft= 94,200ft^3
✔✔What is a volume of a settling tank 100ft long, 25ft wide, and 8ft deep? - ✔✔100ft x
25ft x 8ft = 20,000ft^3
✔✔A water treatment plant receives an average flow of 261 gallons per minute, what is
the daily flow to the plant? - ✔✔261gpm x 60 x 24 = 375,840gallons per day (round up)
380,000 but convert to MGD (gpm/1,000,000) = .38 mgd
✔✔What is the approximate volume in gallons occupied by 15,000ft^3 of water? -
✔✔15,000ft^3 x 7.48 gallons = 112,200 gallons
, ✔✔What is the approximate weight in pounds of 50,000 gallons of water? - ✔✔One
gallon of water weighs 8.34lbs
50,000 x 8.34 = 417,000
✔✔The flow in 35,000 gallons per day. What is that in MGD? - ✔✔.035MGD
✔✔What does one cubic foot of water weigh? - ✔✔7.48gal x 8.34lbs = 62.4lbs
✔✔If the pressure gauge at the bottom of a 200ft standpipe reads 68psi what is the
static head in feet? - ✔✔1psi = 2.31ft of elevation
68psi x 2.31ft x= 157ft
✔✔What is the chlorine demand if the residual is 0.6mg/L and 6.6mg/L has been
applied(dosage)? - ✔✔Demand = dosage - residual
6.6mg/L - .06mg/L = 6.0mg/L
✔✔How many gallons per minute is a flow of 1.0MGD - ✔✔MGD / = gallons per
min
1,000,000 gallons / = 695gpm
✔✔You have an 8'' pipe that is a 2500' long and you want to dose 50mg/L. How many
lbs of cl2 would you need? - ✔✔First find the volume of the pipe
3.14 x .33ft x .33ft x 2500ft = 854.87ft^3
Then convert to gallons
7.48 gallons x 854.87ft^3 = 6,394 gallons
.006394 MGD
Then use the following formula to complete the problem
lbs = MGD x 8.34 x mg/L
.006394MGD x 8.34lbs x 50mg/L = 2.66lbs of CL2
✔✔Three and one half mile of 8in pipe - assuming the ditch is 2ft wide and 4ft deep-
how many cubic yards of soil will be displaced in this project? - ✔✔V= L x W x H
first convert 3.5 miles to feet so 3.5miles x 5280ft = 18,480ft
18,480ft x 2ft x 4ft = 147,840ft
1 cubic yard of water contains 27ft^3 of water
147,840ft^ft^3 = 5,475.55yds
✔✔Your next job task is the installation of three and one half miles of 8in pvc main lines.
the pipe will be supplied in 20ft sections. How many sections will you install? -
✔✔3.5miles x 5280ft = 18,480ft
18,480ft / 20ft = 924 sections of pipe
✔✔In a cubic foot of water there are __________ gallons. how many gallons are there
in 9 cubic feet of water? - ✔✔7.48 gal and 67.32 gal
