In Texas, water operator licensing is administer by the? - (ANSWER)TCEQ
Which minerals cause hardness in water - (ANSWER)magnesium and calciumT
the most importan federal law impacting the water utility industry is - (ANSWER)Safe Drinking Water
Act
The four water quality standards established for drinking water in the Safe Drinking Water Act are
chemical, bacteriological,radiological and - (ANSWER)chemical, bacteriological,radiological and
physical.
The minimue allowable pressure in the distribution system under emergency conditions is -
(ANSWER)20 psi
Water vapor given off by plants and trees is know as - (ANSWER)tranpiration
organic matter includes - (ANSWER)wood,dogs,algae,bacteria
The single most important water treatment process is - (ANSWER)disinfection
excessive nitrates in drinking water can cause what syndrom in infants - (ANSWER)blue baby
A sanitary control easement must cover land within how many feet of a public water well -
(ANSWER)150 feet
A sample for physical and chemical analysis of a new well must be taken after how many hours of
continuous pumping - (ANSWER)36 hours
,Chapter 290 Rules and Regulations requries chemical analysis of water supplies every - (ANSWER)year
Detention time in sedimetation basins must be at least how many hours to allow floc to settle -
(ANSWER)six
backwashing should expand the filter media by - (ANSWER)30 to 50 percent
In Texas, all public water systems are required to have what facilities - (ANSWER)chlorination
The MCL for Trihalomethanes in drinking water is - (ANSWER)0.080 mg/l
At room temperatures chlorine gas is - (ANSWER)greenish-yellow , has pungent odor, and is 2.5 heaver
then air
Disease that may be spread by inadequately disinfected water are - (ANSWER)typhoid, cholera,
infectious hepatitis, legionnaires disease.
minimum chlorine residuals of free and toral in the far reaches of the distribution system is -
(ANSWER).2/.5
Parameters that effect coagulation are - (ANSWER)Turbidity, PH and Alkalinity
coagulant and dosage.
Do not work in a trench ________ feet or deeper unless it is protected from cave-in - (ANSWER)5 feet
Place spoil banks at least ________ feet from the excavation - (ANSWER)2
dose new water mains with a minimum of ----mg/l or more chlorine for at least how many hours -
(ANSWER)100mg/l-3hours or 25mg/l -24 hours
, one bacteriological sample is required for each ------ of new completed main - (ANSWER)1000 feet of
line
A cross connection is a physical connection between a public water supply and ? - (ANSWER)1)
another supply of unknown or questionable quality 2) any source that may contain contamination and
3) any water that is treated to a lesser degree.
maximum spacing between ladders in a trench is - (ANSWER)50 feet
when should a rapid sand filter be backwashed? - (ANSWER)when its dirty, when water will no longer
pass through the filter, loss of head of 6 to 10 feet, turbidity reading higher than 0.5 NTU
a ditch 4 feet wide , 6 feet deep and 1000 feet long will ve excavated . how many cubic yards of pipe
bedding will be needed to to bed the trech 7 inches deep. - (ANSWER)This is a volume question. so
you would multiplied 4 feet by 1000 feet and convert this 7 inches to percent them multiplied that to
get your leanth times with times height . that gives you the cubic feet so you need to devide by 27 to
get the cubic yards 85.9 yd3
how many gallons will 5000 feet of 18 inch water pipe hold ? - (ANSWER)this is volume question so
find the volume of a cylinder. convert 18 to feet first then 3.14x r squared x 7.48 (1 cubic foot of water)
so this one will look like 3.14x.75x.75.5000x7.48=66057.75 gallons ( round up)
A tank that has a capacity of 700,000 gallons must be disinfected with a dosaged of 50 mg/l of
chlorine. how much 65% HTH will it take to achive the same goal - (ANSWER)mgdx8.34.50 is your
normal forumal to find lbs of chlorine. how ever we need that is for 100 % we have 65% so you will
need to .7mgdx8.34x50mg/l /.65 =449.07
The minimum residual water pressure required by Rules and Regulations for publics water systems (30
TAC Chapter 290 subchapter D ) is - (ANSWER)20 psi under demand conditions
Dead end mains should be flushed every - (ANSWER)month
water hardness is caused by - (ANSWER)calcium and magnesium salts