7.0 Water Distribution System

Question 1

Horizontal separation

Answer 1

• Fraser Health Authority requires a min. of 3.0metre separation between the water mains, sanitary sewer, and storm sewers
• 1.5m separation for large structures such as abutments, columns, footings, reservoirs, valve chambers, pumping stations
• Utility separation from the property line should be 1.0 metres

Question 2

Vertical separation

Answer 2

• Clearance of 0.5metres
• Wrap the joints of the water main 3 metres on both sides extending the sewer crossing

Question 3

WM Location

Answer 3

• 1.0 metre min offset from property line
• Underneath sidewalk panels and driveway should be avoided

Question 4

WM Depth

Answer 4

• Minimize use of trench shoring
• Deep enough to prevent freezing, provide adequate clearance, protect from external loads
• At least 1.0 metre to finish grade
• Under ditches: 0.5m and have pre-cast concrete slab to protect
• Not to be over 1.5 metres unless approved

Question 5

WM grade

Answer 5

• Min slope 0.1%
• If it exceeds 10%, the material should be ductile iron, and anchor pipe

Question 6

Ductile iron

Answer 6

• Strong
• Centrifugal casting
• Inside coated with cement
• Joined using push-on or mechanical joints
• 3-64 inches diameter

Question 7

PVC (Polyvinyl chloride)

Answer 7

• Most widely used
• Low cost and high durability
• Colour-coded
• 2-60 inch diameter

Question 8

HDPE (High-Density Polyethylene)

Answer 8

• It does not require rubber seals or jointing chemicals
• 1.25-48 inch diameter

Question 9

CPP (Concrete Pressure pipe)

Answer 9

• For high loads and pressure
• Steel joint rings, rubber gaskets
• No maintenance
• 14-140 inch diameter

Question 10

Standard Dimension Ratio

Answer 10

• Used in the PVC pipe industry
• Divide AVG outside diameter by min. Pipe wall thickness

Question 11

Looping system

Answer 11

• Preferred
• Redundancy
• Water quality
• Cooperation during fire
• Approximate demands

Question 12

Dead-end system (tree system)

Answer 12

• Unreliable
• Water quality
• Stressed during fire
• Uncertainty
• Allowed when the following conditions are met
  1. The water main serviced single-family residential zoned lands
  2. The length of dead main is less than 100m
  3. The maximum size of the main is 100mm
• Water mains should be reduced in size after the last fire hydrants (volume and speed)

Question 13

Fittings

Bends

Answer 13

• Curved fittings that allow pipes to change direction
• Standard angles: 11.25, 22.5, 45, 90

Question 14

Fittings

Couplings

Answer 14

Connect two pipes together

Question 15

Fittings

Tees (crosses)

Answer 15

• Split the flow of water in two directions
• Combine two flows into 1
• Connect smaller pipe to main line

Question 16

Fittings

Reducers

Answer 16

• Connect pipes of different diameters
• Large to small to maintain proper flow and pressure

Question 17

Fittings

Plugs

Answer 17

Close off the end of the pipe