GRADE 1 WATER DISTRIBUTION STUDY COMPREHENSIVE
QUESTIONS AND VERIFIED DETAILED SOLUTIONS
( MULTIPLE CHOICES) |100% CORRECT!!
Which agency sets legal limits on the concentration levels of harmful
contaminants in potable water distributed to customers?
a. National Primary Drinking Water Regulations Agency
b. US EPA
c. US Public Health Service
d. Occupational Health and Safety Administration Correct Answers B
The number of monthly distribution system bacteriological samples
required is
a. based on the water withdrawal permit limit
b. based on the system size
c. based on population served
d. different for each state Correct Answers c
What is the maximum contaminant level for TTHM in the united states?
Correct Answers .08
Under the Surface Water Treatment Rule, disinfection residuals must be
collected at the same location in the distribution system as?
a. coliform samples
b. total tthms
c. disinfection by products
,d. alkalinity, conductivity, and pH for corrosion studies Correct Answers
a
Iron can cause "red water" and thus customer complaints when its
concentration is above its secondary maximum contaminant level of:
a.) 0.01 mg/L
b.) 0.05 mg/L
c.) 0.10 mg/L
d.) 0.30 mg/L Correct Answers d
The goal of the Surface Drinking Water Act is for each ________ to
accept primary enforcement responsibility (primacy) for the operation of
the state's drinking water program.
a. state
b. water treatment plant
c. operator
d. municipality Correct Answers a
What is the objective of the Total Coliform Rule?
a. to provide Cryptosporidium protection in new facilities
b. to ensure safe levels of lead and copper
c. to protect the public from exposure to giardia lamblia and crypto
d. to promote routine surveillance on system water quality to search for
fecal matter and/or disease-causing bacteria Correct Answers d
,Which agency sets standards on concentration levels of harmful
contaminants in drinking water? Correct Answers USEPA
Explain the difference between the different tiers of violations. Which
one is the most serious? Correct Answers Tier 1 is an acuty MCL
violation requiring public notification within 24 hrs. Tier 2 notification
must occur within 30 days. Tier 3 require notification within 1 year.
A positive E. coli test must be reported to the primacy health agency
within what period of time? Correct Answers 24 hours
How is the required number of monthly bacteriological samples
determined? Correct Answers Population served
What is the action level for lead in first draw samples taken from
customer taps? Correct Answers .015 mg/L
A water system is designated a community public water system if it
serves how many homes? Correct Answers 15 or more
What authority provides specific water sampling instructions? Correct
Answers the state primacy agency
According to the Lead and Copper Rule, what is the action level for
lead? Correct Answers 0.015 mg/L
, Determine the detention time in hours for the following water treatment
system: Distribution pipe from water plant to storage tank is 549 feet in
length and 14 inches in diameter. Storage tank averages 2,310,000
gallons of water at any given time. Flow through system is 6.72 mgd.
Correct Answers 8.3 hours
divide daily flow by 24 hours in a day (280,000)
then divide 280,000 into tank capacity
If chlorine is being fed at a rate of 260lb/day for a flow rate of 23cf/s,
what should be the adjustment on the chlorinator when the flow rate is
decreased to 16 cf/s if all other parameters were to stay the same?
Correct Answers 180lb/day
260/23=x/16
divide 260 by 23, then multiply that by 16
How many gallons of sodium hypochlorite solution that contain 12.1%
available chlorine are needed to disinfect a 1.5ft diameter pipeline that is
283 feet long, if the dosage required is 50 mg/L? Assume the sodium
hypochlorite is 9.92 lb/gallon. Correct Answers 1.3 gallons sodium
hypochlorite
sodium HCl=[(mil gal)(dosage)(8.34)]/[%avail Cl2/100%]
QUESTIONS AND VERIFIED DETAILED SOLUTIONS
( MULTIPLE CHOICES) |100% CORRECT!!
Which agency sets legal limits on the concentration levels of harmful
contaminants in potable water distributed to customers?
a. National Primary Drinking Water Regulations Agency
b. US EPA
c. US Public Health Service
d. Occupational Health and Safety Administration Correct Answers B
The number of monthly distribution system bacteriological samples
required is
a. based on the water withdrawal permit limit
b. based on the system size
c. based on population served
d. different for each state Correct Answers c
What is the maximum contaminant level for TTHM in the united states?
Correct Answers .08
Under the Surface Water Treatment Rule, disinfection residuals must be
collected at the same location in the distribution system as?
a. coliform samples
b. total tthms
c. disinfection by products
,d. alkalinity, conductivity, and pH for corrosion studies Correct Answers
a
Iron can cause "red water" and thus customer complaints when its
concentration is above its secondary maximum contaminant level of:
a.) 0.01 mg/L
b.) 0.05 mg/L
c.) 0.10 mg/L
d.) 0.30 mg/L Correct Answers d
The goal of the Surface Drinking Water Act is for each ________ to
accept primary enforcement responsibility (primacy) for the operation of
the state's drinking water program.
a. state
b. water treatment plant
c. operator
d. municipality Correct Answers a
What is the objective of the Total Coliform Rule?
a. to provide Cryptosporidium protection in new facilities
b. to ensure safe levels of lead and copper
c. to protect the public from exposure to giardia lamblia and crypto
d. to promote routine surveillance on system water quality to search for
fecal matter and/or disease-causing bacteria Correct Answers d
,Which agency sets standards on concentration levels of harmful
contaminants in drinking water? Correct Answers USEPA
Explain the difference between the different tiers of violations. Which
one is the most serious? Correct Answers Tier 1 is an acuty MCL
violation requiring public notification within 24 hrs. Tier 2 notification
must occur within 30 days. Tier 3 require notification within 1 year.
A positive E. coli test must be reported to the primacy health agency
within what period of time? Correct Answers 24 hours
How is the required number of monthly bacteriological samples
determined? Correct Answers Population served
What is the action level for lead in first draw samples taken from
customer taps? Correct Answers .015 mg/L
A water system is designated a community public water system if it
serves how many homes? Correct Answers 15 or more
What authority provides specific water sampling instructions? Correct
Answers the state primacy agency
According to the Lead and Copper Rule, what is the action level for
lead? Correct Answers 0.015 mg/L
, Determine the detention time in hours for the following water treatment
system: Distribution pipe from water plant to storage tank is 549 feet in
length and 14 inches in diameter. Storage tank averages 2,310,000
gallons of water at any given time. Flow through system is 6.72 mgd.
Correct Answers 8.3 hours
divide daily flow by 24 hours in a day (280,000)
then divide 280,000 into tank capacity
If chlorine is being fed at a rate of 260lb/day for a flow rate of 23cf/s,
what should be the adjustment on the chlorinator when the flow rate is
decreased to 16 cf/s if all other parameters were to stay the same?
Correct Answers 180lb/day
260/23=x/16
divide 260 by 23, then multiply that by 16
How many gallons of sodium hypochlorite solution that contain 12.1%
available chlorine are needed to disinfect a 1.5ft diameter pipeline that is
283 feet long, if the dosage required is 50 mg/L? Assume the sodium
hypochlorite is 9.92 lb/gallon. Correct Answers 1.3 gallons sodium
hypochlorite
sodium HCl=[(mil gal)(dosage)(8.34)]/[%avail Cl2/100%]
