TEXAS WASTEWATER D MAIN EXAMINATION SET QUESTIONS AND SOLUTIONS RATED A+

TEXAS WASTEWATER D MAIN EXAMINATION SET
QUESTIONS AND SOLUTIONS RATED A+
✔✔The purpose of the sample site plan is to assure bacteriological samples are
collected from ______ service connections which are representative of the distribution
system. - ✔✔active

✔✔T/F: Keep the sample in ice or in a cooler prior to and during lab transport because
heat stimulates bacterial growth. - ✔✔True

✔✔The action level for lead is _______ mg/L and for copper it is _____ mg/L. - ✔✔.015
/ 1.3

✔✔T/F: Low doses of heavy metals such as lead and copper can cause damage to the
central nervous system over time. - ✔✔True

✔✔A certain group of bacteria is used to indicate the possible presence of a pathogen--
- the ________ group. - ✔✔Coliform

✔✔Disinfection is the destruction of disease-causing microorganisms called ______. -
✔✔Pathogens

✔✔At room temperature chlorine is a greenish-yellow gas that is ___ times heavier than
air. - ✔✔2.5

✔✔The State requires ________ to be kept in stock for disinfecting new water lines. -
✔✔Calcium hypochlorite

✔✔T/F: Hypochlorinators consist of a mixing tank and chemical solution feed pump. -
✔✔True

✔✔A full-face self-contained breathing apparatus or supplied air respirator must be
readily accessible outside the fire station when chlorine gas is used. - ✔✔False (A full-
face self-contained breathing apparatus (SCBA) or supplied air respirator that meets
OSHA standards shall be readily accessible outside the *chlorinator room* when
chlorine gas is used.)

✔✔T/F: All public water systems must have chlorination facilities. - ✔✔True

✔✔If chlorine enters the eyes, flush with running cool water for at least ___ minutes and
seek medical attention. - ✔✔15 minutes

✔✔Liquid bleach used in PWS must be ______ approved. - ✔✔NSF

, ✔✔T/F: Primary components of a gas feed chlorinator include an injector, flowrate
controller, rotameter, and mixing tank. - ✔✔False (injector, vacuum regulator, flowrate
controller, rotameter- *not a mixing tank*)

✔✔The maximum sustained gas withdrawal rate for pressure transmission 150 lb
cylinders is ____ lbs/day - ✔✔40

✔✔T/F: Utility operators use chlorine in three commercial forms:
1) pure chlorine in the liquid or gas state
2) bleach solutions
3) granular/tablet compounds - ✔✔True

✔✔T/F: If chlorine contacts the skin, flush with an emergency shower or garden hose
for at least an hour. - ✔✔False (15 minutes)

✔✔Hypochlorous acid is the disinfectant and the _____ residual. - ✔✔Free

✔✔If a major chlorine leak occurs, call the supplier and ______. - ✔✔TCEQ

✔✔The rotameter indicates the feed rate in _____ per day - ✔✔pounds

✔✔T/F: Chlorine reacts with hydrocarbons producing heat or fire - ✔✔True

✔✔Chlorinator rooms must be provided with facilities from determining the amount of
disinfectant used _______ - ✔✔daily

✔✔T/F: Dosage is the amount of chlorine applied in milligrams per liter or parts per
billion. - ✔✔False (parts per million)

✔✔DPD reacts with chlorine producing a pink to ____ color. - ✔✔red

✔✔T/F: Residual is the amount of chlorine left after the demand is met. - ✔✔True
(Dosage: How much Cl you put in the system, Demand: How much Cl is used by the
system, Residual: How much Cl is left over)

✔✔T/F: TCEQ requires a faucet for raw water sampling on the discharge pipe of each
PWS well. - ✔✔True

✔✔Permeability is the ability to _____ water through the aquifer. - ✔✔transmit

✔✔T/F: The difference between the static level and pumping level is call the drawdown.
- ✔✔True