Questions and Answers| Latest Update
Gravity filters will remove which of the following from surface water supplies:
a) turbidity
b) taste and odors
c) nitrates
d) hardness
e) chlorides a) turbidity
If you added 3.5 mg/L of chlorine to your storage tank and 30 minutes later measured the
residual at 1.2 mg/L, what was the chlorine demand in the tank?
a) 4.2
b) 2.9
c) 0.3
d) 2.3
e) 4.7 d) 2.3
Your ground storage tank is 15 feet high and 30 feet in diameter. About how much water can it
hold?
a) 31,700 gallons
b) 79,270 gallons
c) 50, 490 gallons
,d) 25,150 gallons
e) 10,600 gallons ...
When fecal coliform organisms are found in a water supply, it is an indication that:
a) the water supply is contaminated
b) pathogenic organisms might be present
c) the water may be unsuitable for drinking
d) follow-up sampling must take place
e) all of the above e) all of the above
Which of the following is an acceptable level of residual chlorine in the far reaches of a
distribution system?
a) 0.2 mg/L of free chlorine for a small GWS
b) 0.5 mg/L of chloramine for a large SWS
c) 1.0 mg/L of combined when using ammoniation facilities
d) 1.0 mg/L of total for a large SWS
e) all of the above e) all of the above
The purpose of an air line on a well is to:
a) aerate the well
b) determine the depth of the aquifer
c) inject chlorine into the well
d) allow the well to breathe
, e) determine the water level e) determine the water level
The drawdown of a well is determined by:
a) a properly installed air line
b) the difference between the static and pumping level
c) a psi gage calibrated in feet of water
d) a tape measure
e) an electronic sounder b) the difference between the static and pumping level
A common type of oxidant that is used at most SW treatment plants to kill bacteria and to
prevent trihalomethane formation is:
a) total chlorine
b) combined chlorine
c) chlorine dioxide
d) free chlorine
e) ozonation b) combined chlorine
A PWS is responsible for providing:
a) potable water
b) adequate water pressure
c) an adequate quantity of water
d) all of the above