Water Exam 1

When digging a trench for a water main, the person qualified to choose the correct type of shoring required for the trench is the

When comparing water main pipe, what does a high C value indicate?

A positive result of the coliform presence/absence test is an indication that you may have which type of contamination?

What does a red USA marking on the ground near the excavation site for a new water main indicate?

A water supply system is considered to be disinfected when

One reason you might consider changing your residual disinfectant from free chlorine to chloramines is to

All water supplies used to serve the public, regardless of the source or treatment received should be

Thrust blocks are installed to prevent

Which of the following is the best method of preventing back flow in a distribution system?

Which of the following must be installed between a water main and connected fire hydrant?

Which component of a centrifugal pump is sometimes installed on the end of the suction pipe in order to hold priming?

A device used to check flows in a distribution system is called a

The type of corrosion caused by the use of dissimilar metals in a water system is

An air gap technique is used to

The pH scales ranges from

Which of the following is a health related primary acute toxic contaminant?

Minimum recommended set back for a fire hydrant to the curb face is?

A theoretical line measured from the center line of a water main is called a

Contaminants which may affect public health after a short term exposure include

Which water quality parameter should be measured before the addition of coagulant chemicals in the coagulation process?

The culture medium used in the presumptive test is

Which chemical compound is generally used to control algae in fresh water lakes and reservoirs?

Which type of valves are frequently used as a corporation stop or curb stop in the water distribution system?

A sacrificial anode is something you would use in which process?

Turbine & propeller are examples of

A leak in the wall of a pipe can be repaired with

Corrosion on the inside of a water pipe can cause

A primary source of VOC contamination in water supplies is

Chlorine demand increases when ________ increases

Sodium Hypochlorite is

Groundwater generally requires less treatment than surface water for

The discharge rate of a piston-type pump

Vibration in pumps may be caused by improper motor pump

The leakage of a water seal around the packing of a centrifugal pump is required because it acts a an

The component of a centrifugal pump that is sometimes installed on the end of the suction pipe to hold the priming is known as

What type of valve is used to control reservoir levels?

Distribution system pressure (even during fire fighting demands) should not be allowed to drop below ______psi.

A trench must be shored if it is ____ feet deep or more.

The coupon test can be used

Anaerobic bacteria live:

What type of map provides a clear picture of the entire distribution system?

Which corrosion inhibitor is most effective in controlling lead in distribution system water?

Which of the following does not have an effect on chlorine's disaffection efficiency?

Chlorination is used to

When using chlorine tablets to disinfect a pipeline during installation, the tablets should be placed

What is the chlorine demand if the residual is 0.6 mg/L and a dose of 6 mg/L had been applied?

Determining the pH is an important water quality test. The results indicate a

A pH of 5 indicates the water sample is

Calcium hypochlorite:

Disease causing bacteria are called

In the distribution system normal flows should not exceed

The type of hydrant that has valves located at each individual outlet is called the _______ hydrant.

A ground water well that provides drinking water to a school with less than 15 service connections is classified as a

Sewer lines should be separated from potable water mains by at least ______ vertical and _____ parallel.

The flexural strength of pipe material is the ability to

The AWWA recommended water main flushing velocity for bio-film removal is?

A trench must be shored if it is _______ feet deep or deeper

When employees are working in trenches requiring ladders, these exists must be located no further than ______ apart.

Cal-OSHA considers an open trench _______ or deeper a possible hazardous atmosphere condition.

Hard water caused by calcium and magnesium can?

Which of the following is primarily used to de-chlorinate water

Chlorination is used to

PH refers to:

Gas chlorination when operating at a high rate of withdrawal from the chlorine cylinder, can result in:

The maximum exposure for noise during an eight hour period is:

Who is responsible for your safety?

Permit required confined space entry requires:

Which gas is the most toxic to humans when inhaled?

The term aquifer refers to:

Firefighting may cause low pressure in an area of the distribution system. This low pressure might lead to:

What do the orange lines on the ground indicate?

When you grab a sample from a main, where would you get the least residual.

Valves are provided in a distribution system to

A connection that is made into a main that is full or under pressure is called a:

A backflow preventer is a device used to:

Chloramines are:

Coliform bacteria are most prevalent in:

Sample bottles which are furnished by a certified laboratory for collection of bacteriological samples

Hardness is caused by:

Never apply to water to a gaseous chlorine leak because the water will:

Chlorine demand is:

Your chlorinating a well supply and the chlorine demand jumps from 0.9 mg/L te 3.0 mg/L. This is an indication of:

How many lbs. Of chlorine gas per day can be withdrawn from 150 Ib cylinder operating at normal room temperature?

Which of the following is a positive displacement pump?

When using the AWWA spray method for disinfecting the interior walls of water tanks, the minimum applied chlorine dose is