What is the minimum pressure required in the distribution system?

20 psi

The distribution system must have a minimum of _mg/L in the distribution mains.

0.2 mg/L

What is the minimum combined residual for the distribution system?

0.6 mg/L

What is the maximum free or combined chlorine residual in the distribution system?

4 mg/L

Valves on distribution mains should be how far apart?

800-1,000

How far apart are fire hydrants in residential areas?

500'

Fire hydrants in commercial areas should be how far apart?

No more than 300' from any part of a commercial building

How often should water main valves be exercised?

At least once a year

What is the main purpose of water storage tanks?

What is the configuration of a standpipe?

It is taller than it is wide

How many feet apart should a ladder be in a trench?

No more than 25' from any worker

How many ladders will you need for a 100' trench?

2 (25' from each end)

How far out of the trench should the ladder extend?

30"

When belled pipe is being installed, the bells are usually pointed in the direction that the work is heading except when the pipe is headed downhill, then the bell should?

Face uphill

How many feet from trench should the spoil bank be placed?

Minimum of 2 ft.

Excavations five feet or deeper must be?

Shored

Before doing any excavation work, you must?

Call for/Get Underground Locations

Any excavation or tank four feet or deeper is considered?

A Confined Space

Barricades with diagonal stripes must have the stripes?

Sloped toward traffic

When a pipeline changes direction or sizes, at dead ends, and when valves or hydrants are closed rapidly ______ must be installed?

Thrust Blocks

Water mains should be installed at least ______ horizontally from sewer mains.

10'

Water mains should be installed at least ______ higher than a sanitary sewer pipe.

1'

Surge Tanks are used to control?

Water Hammer

Where are air relief valves located in a distribution system?

At High Points

Hydropneumatic tanks should be equipped with?

Relief Valves

What type of valve is located at a point that is below the hydraulic gradient?

Altitude Valve

When should storage tanks be taken out of service for maintenance?

During periods of low demand

How do you disinfect the interior of a storage facility?

Spray or brush interior with a 200-PPM Cl₂ Solution

What is the minimum chlorine dosage to disinfect a newly installed main?

25 mg/L for 24 hours

The most commonly used joints on installed pipes are?

Push on joints

When should fire hydrants be inspected and serviced?

Twice a year

Where is the operating valve located in a dry barrel fire hydrant?

At the bottom

Distribution mains should be installed in a ог design to avoid dead ends?

Grid or Looped System:

What is a wet tap?

Installation/tap made under pressure

When a pipeline has been installed, the first layer of backfill is compacted to which point?

Up to the horizontal centerline of the pipe

A newly installed main is tested at a pressure higher than expected operating pressure or ________ psi for 24 hours?

50%, 250 PSI

What is measured after the completion of the pressure test?

Water loss or leakage

What is the chief purpose for of storage tanks?

To meet peak hourly demand