Chapter 6: Application of Backflow P. Procedures

Question 1

What protects the purveyor’s water system from any actual or potential hazardous CC on a customer’s premises?

Answer 1

Premises Isolation

Question 2

What is an advantage to Area Protection?

Answer 2

One backflow preventer can isolate several hazards

Question 3

What is a disadvantage of Area Protection?

Answer 3

All hazards w/in the area may not be protected / may need to be periodically re - surveyed

Question 4

What is, the practice of installing a backflow preventer or air gap at the point of each CC?

Answer 4

Individual protection

Question 5

What is a dual distribution system?

Answer 5

A multi water distributions on a building

Question 6

What type of hazard is a car wash?

Answer 6

Severe hazard

Question 7

Any facility that has chemicals in it is considered to be what type of hazard?

Answer 7

Severe

Question 8

When would an RP need an Air Gap as well?

Answer 8

Waste water treatment plants, sewage pump or lift stations
Radioactive material processing plants or nuclear reactors

Question 9

What uses purple pipe or has purple lettering or tape on it?

Answer 9

Non-potable that is downstream of a backflow preventer

Question 10

Where does greywater come from?

Answer 10

untx household wastewater which has not come into contact w/ toilet waste or food processing waste

Question 11

True or False: Dairy farms require a RP and Farms needs a DCVA

Answer 11

True

Question 12

Multi Storey buildings, offices or apartments require what type of backflow preventer?

Answer 12

DCVA or RP

Question 13

New water main construction pipes need to be flushed with what?

Answer 13

High chlorine concentration used for disinfection procedures (25 - 50 parts per million for 24 hours)

Question 14

The practice if installing a backflow preventer at the source of possible contamination is knows as?

Answer 14

Internal Protection: area, zone, or individual
(fixture) protection.

Question 15

The practice of installing a backflow preventer on the water service to a building is known as?

Answer 15

Premise Isolation

Question 16

What are the advantages to using internal isolation over premise isolation?

Answer 16

Because the occupants of the building as well as the system supply are protected, and in some cases the backflow preventer can be sized smaller.

Question 17

Water used in cooling systems is often treated with chemicals for what reason(s)?

Answer 17

Algae, pollutants, corrosion control

Question 18

What does a water purveyor consider to be “used water”?

Answer 18

Any water that has left purveyors system and enters property

Question 19

Why is a property that has an auxiliary water supply considered to be a severe hazard requiring premise isolation?

Answer 19

Because the water purveyor has no knowledge of the hazards or risks that exist on a property with an auxiliary system, worst-case scenarios must be assumed.

Question 20

What type of backflow preventer would be recommended for use in a premise isolation?

Answer 20

RP at the property line.

Question 21

What type of fire protection system requires no backflow protection?

Answer 21

Anything using potable water
A full flow-through residential fire sprinkler/standpipe system

Question 22

Why might a dockside water supply to a freshwater dock be considered a higher hazard than one located on a saltwater dock?

Answer 22

Can taste saltwater
Because most people would
not assume there to be much of an issue interconnecting lake water with the public potable system, where they would naturally see interconnecting saltwater to be detrimental. Also the lack of salty taste would allow an interconnection to lake water to go unnoticed.

Question 23

What are they three types of heat exchangers listed / how do they differ?

Answer 23

1) Single wall (SW)
2)double wall (DW)
3)double wall with leak detection
(DWP). Only the DWP type carries the IAPMO endorsement and would not require any backflow preventer. Selection of backflow preventer depends
on degree of hazard based on piping materials and use of chemicals.