Questions and Answers(Graded A+)
The minimum and maximum chloride residual in a water distribution system is ? -
ANSWER-0.2 mg/l and 4mg/L of free chlorine
Nitrate may not exceed what concentration when tested yearly for a groundwater
treatment plant ? - ANSWER-10 mg/L
The minimum number of total coliform samples that must be collected per month is
based on Wich of the following ? - ANSWER-The population served by the system
When a distribution bacteriological sample is positive for a total coliform the
procedure is ? - ANSWER-Repeat the sample and take a sample 5 connections
upstream and downstream to confirm total coliform
For lead and copper sample the water must be In the pipeline for at least? -
ANSWER-6 hours
What is hydraulic grade line ? - ANSWER-A line to which the water level would rise
in a small ,vertical tube,connected to the pipe
How often should cathodic protection anodes in your system be inspected? -
ANSWER-Every year
Water pipelines are generally designed to carry water at a velocity below ? -
ANSWER-2.5b FPS. Feet per second
Energy use in water systems is defined best by ? - ANSWER-Energy use varies
among systems and an energy inventory study would need to be conducted to
determine relationships
The minimum recommended separation distance between a water main and a storm
sewer is ? - ANSWER-6 feet
Which of the following should be in an organization plan ? - ANSWER-Identifies clear
lines ,defines the divisions of labor ,establishes unity of command
If pipelines are not restrained using steel rods concrete thrust blocks can be used
at ? - ANSWER-Every bend and transition
Engineering Drawings that show the depth of pipe, the pipe location both vertically
and horizontally and the correct distance form a reference point are known as which
of the following - ANSWER-Plan and profile drawings
, Which are the components of directing staff ? - ANSWER-Motivating &
communicating
The accuracy of large meters should fall within what range ? - ANSWER-Not less
than 97% not more than 103%
In some older water system lead service line still exist. What would be the best
practice when finding lead pipe ? - ANSWER-Be replaced
What is the acceptable range for water loss in a typical municipal distribution system
that has a variety of pvc and di pipe ? - ANSWER-20% (80% effienciency)
What is a major cause of underground construction deaths ? - ANSWER-Lack of
shoring or shoring failure
If the tds is marginally too high for the pump the likely result will be ? - ANSWER-
Decrease in flow rate
Air release valves are installed at what location in a water line ? - ANSWER-At high
points of a pipe line
The maximum pressure at service connections should be less than ? - ANSWER-
100 psi
In selecting and Evaluating a tank, storage capacity must be matched _______of the
system ? - ANSWER-Peak demand
A hydraulic grade line will always slope in what direction ? - ANSWER-Slope
downward in the direction of the water flow
Where does the majority of microbial growth with in a water distribution system occur
? - ANSWER-Dead end water lines
Wells that are biologically contaminated from repeat coliform or fecal coliform must
be bacteriologically surveyed and sample which is not correct ? - ANSWER-They
must be at least 12 hours apart
When backfilling a pipe line how deep should the first layer of backfill be compacted -
ANSWER-At the horizontal centerline of the pipe
What is an important step in problem solving - ANSWER-Realization that a problem
still exist
What type of pipe joint is a considered inflexible and therefore is not usually installed
below ground ? - ANSWER-Flanged joint
buttefly valves are used in distribution systems ? - ANSWER-Generally when the
pipeline is greater than 16''.
When someone throttling might be replaced .