Waste water study sample questions

Influent can be best defined as ?

The flow of waste water entering the collection system

The highest dissolved oxygen content may be expected in a facultative lagoon at?

3pm

Another word or phrase for nutrients ?

Fertilizer

(Nitrogen and Phosphorous)

A long hot period may cause overloading of a lagoon by ?

Lowering the DO saturation level

Hydrogen sulfide gas smells like?

Rotten Eggs

The primary purpose of forced draft ventilation in lift stations is to?

remove dangerous gases

Sand , Silt , and Grit are mainly composed of what kind of matter?

Colloidal

Check valves are used to ?

Permit flow in only ONE direction.

A composite sample will provide a (an)?

Representative sample

Dike vegetation should be controlled by

Mowing periodically

The purpose of a sludge drying bed is to ?

Convert digested sludge into a good fertilizer

If there is an insufficient supply of air or oxygen being introduced into the aeration tank of an extended aeration plant, the liquid in the tank will likely ?

Have a black or blackish appearance and an offensive odor

which of the following plants has a root system that would harm the seal in the pond?

Cattails

An operator cannot maintain an adequate water level in one of the ponds… What will cause this to happen?

the pond seal leaks

An operator should never enter a room containing a high concentration of chlorine gas without?

having a self contained air or oxygen supply and help standing by

Under ice and snow cover, the BOD level in the ponds will normally?

Increase slowly

The dangerous gases most likely encountered in the wastewater industry are?

Carbon monoxide

methane

hydrogen sulfide

High concentrations of heavy metals should be prevented by industrial pre-treatment requirements from entering sanitary sewer system because?

They may Affect the treatment process

When an employee breaks the rules and requires discipline who is responsible

Supervisor

How can the supervisor document that scheduled maintenance is completed?

Use a form that compares work assigned with Work completed

The principal purpose of a standard manhole is to what?

Provide access for cleaning and inspection

What are pathogens?

Bacteria or virus that cause disease

What test is not run on the influent?

E. coli

In airgap device is used to ?

Prevent cross connection

What do bacteria do with BOD in raw waste water?

Eat it

Waste water is treated in order to?

Prevent pollution

Protect public health

Remove harmful waste from waste water

Characteristics that should be measured immediately after the sample is collected are?

Temperature, pH, and DO

The location of a leak in a digester gas piping may be best located by

A soapy solution

Manholes are normally located at

Each change in direction of the sewer

Each change in Grade

Each change in size of pipe

What type of valve should be used on the suction side of a centrifugal pump?

Gate

Telemetry is most commonly associated with

Communication in an alarm system

What is a common cause of sludge in the activated sledge process?

Filamentous bacteria

In withdrawing sludge from a digester, it is necessary to allow some sludge to remain in order?

To provide seed material for raw sludge added to the digester

The purpose of adding lime to a failing digester is

To raise the pH

Cavitation is best to defined as

The formation and collapse of a gas pocket or bubble on the blade of an impeller

The term "activated sludge" refers to?

The brownish flocculent culture of organisms developed in an aeration tank under controlled conditions

Electric power may be measured in?

Kilowatts

Watts

The bacteria used in the activated sludge process?

Are normally present in any domestic wastewater

Mixed liquor is?

A mixture of activated sludge and wastewater in the aeration tank undergoing activated sludge treatment

The primary purpose of wastewater lift stations in collection systems is to?

To lift the wastewater to a higher elevation where it can flow by gravity

If you are major wastewater treatment or a 1 MGD plant, annual sludge reports are due to EPA no later than

February 19 of the following year

Which of the following is not biologically active in a lagoon?

Fungi

What is the proper method for preserving the sample for BOD and TSS test?

Refrigerate at 4°C or keep on ice

Schedule 40 refers to

Wall thickness

If a piece of equipment fails, but there is no danger to the public, the repair of this equipment would be classified as

Corrective maintenance

The pressure against which a pump must operate is measured in terms of

Psi

Defect that cause problems and waste water collection systems include

Improper grade of sewer

Improper taps

Structure failure of manholes

The oxygen content of an oxygen deficient atmosphere is

Less than 19.5%

What information must be included on a warning tag attached to switch that has been locked out

Signature of the person who locked out the switch and who is the only one authorized to remove the tag

Why is duckweed undesirable in waste treatment ponds?

Stops the sunlight penetration

The biochemical oxygen demand, BOD, is based on which of the following

Measuring the dissolved oxygen, DO, used

What are aerobic bacteria?

Bacteria that will live and reproduce only in an environment containing oxygen that is available for their respiration