Continued Flashcards
Separation of water main and sewer
6ft 1ft horizontally and 6” preferably 1ft above
Tuberculation process is?
Chemical Process of buildup of minerals
After chlorine level is met the amount of chlorine in water is called
Residual Chlorine level
Chloramines are formed by combination of chlorine and ?
Ammonia
Back flow is a condition that
Has reversed flow due to pack pressure
Minimum distance that soil pile should be placed from edge of trench
2 feet
How many ladders are required in 4ft trench 100 ft long
Two
What type of pump is used to pump water into a system
Centrifugal pump
Total dynamic head consists of
Suction lift- friction head - discharge head- velocity head
What is static head
Pressure due to depth of elevation of water
What is hydrostatic pressure testing used for in new mains
To locate leaks
Florida drinking water regulations include man contaminant levels except for
Color contaminants
What does 1991 coliform rule require
95 percent of samples must be free of coliform
What affects chlorine disinfectant properties
Temperature
Chlorine is most affective at
Ph of 7
Minimum feet per second water main should be flushed
2.5 feet per second
Max pressure of service connection
Less than 100 psi
What does not describe unindirectional flushing
Uses more water
Total amount of chlorine pumped into a system is called
Chlorine dose
3 methods of disinfecting
Slug, continuous, tablet
Main continuint in water that causes corrosion of metals
Dissolved oxygen
Amount of chlorine used in reaction with inorganic and organic impurities is known as
Chlorine demand
Difference between ground water and surface water
Ground- more minerals
Surface- more toxicants
Back flow is
Reversed flow due to back pressure
Advantage of preventive maintenance
Improved performance
Trench for type c soil should be
1 1/2 to 1 or greater
For lead and copper test water should be in pipe for how long
6 hrs
Where should mains be anchored
When pipe changes size direction and at dead ends
What metal is used as an expendable anode
Magnesium
When does chlorine become corrosive
When moisture is added
How long should MORs sanitary surveys and cross connection control programs reports be kept
10 years
What is caused when there is negative water pressure
Back siphonage
Where should coliform test samples be taken from
Locations tapped directly into the main
Why is sodium thiosulfate added to the microbiological sample bottle
It gets rid of any chlorine residual in the bottle
Hydrant with flow rate of 1500gpm should be what color
Blue
Can a butterfly valve be used for throttling
Yes
Difference between ground water and surface water contamination
Ground water takes longer to recover from contamination
What happens when metals are connected
Galvanic action will occur
If pipeline is not restrained thrust blocks can be used where
Every bend and transition
