T2

Which is the highest recommended stacking height for bags of powdered activation carbon and granular activated carbon?

6 ft

If a water system does not collect a sample for unregulated contaminant monitoring according to federal instructions for a listed contaminant, the failure must be reported to the UCMR sampling coordinator or state within ____ days.

7

Water is flowing through a pipe at a velocity of 3.9 fps. Total flow through the pipe is 1.36 CFS. What is the diameter of the pipe?

8 inches

What percent of the total chlorine residual is free chlorine beyond the chlorination breakpoint?

85% to 90%

What causes the water quality to change once a sample is collected?

Biological activity

From the list below, choose the most common mistake that operators make regarding flocculation unit operation?

Excessive flocculation time

A follow up sample is required if the concentration in the composite sample is greater than or equal to _______mg/L for any contaminant listed in the National Primary Drinking Water Regulations, 141.61 (a)- Organic Chemicals.

0.0005mg/L

The maximum contaminant level for bromate is:

0.010 mg/L

A public water system serving a population greatedrthe 3,300 must not have a disinfectant residual below _____ for more than 4 hours.

0.2 mg/L

According to the IESWTR, a public water system serving more than 10,000 people must have combined filter effluent turbidity less than or equal to _______ NTU on 95% of all samples taken during the month.

0.3

How long does it take for aluminum ions in alum to neutralize negatively charged particles in raw water?

1 to 2 seconds

How large must the sample be for lead and copper analyses?

1,000 mL

Water is being pumped from an elevation of 356 feet. It is being pumped to a reservoir at an elevation of 1.486 feet. What is the total head if friction losses and minor headlosses are 23 feet?

1,153 ft

Pure liquid chlorine is _____ times more dense than water?

1.5

What is the minimum population served that requires a public water system to participate in the Unregulated Monitoring Program?

10,001

The normal detention time in mechanical mixers is typically:

15 to 45 seconds

Repeat samples for a positive coliform sample are required to be collected within ____ hours.

24 hours

A water treatment plant treats surface water with an average raw water TOC concentration of 3.6 mg/L. If the average effluent TOC is 2.2 mg/L, what is the removal efficiency?

39%

How long will is take for Suspended Solids, which are called Settleable Solids, to settle unaided tot he bottom of a sedimentation basin?

4 hours

Which emergency kit is used for repairing a leak on a ton chlorine container?

Kit B

Sequestration is effective only for groundwater that has low levels of dissolved iron and manganese and

no dissolved oxygen

The prohibition on the use of lead for any plumbing in a residential or nonresidential facility connected to a public water system that monitor water for human consumption does not apply to:

repair of cast iron pipes using leaded joints

The coagulant aid activated silica is prepared on site by the treatment plant operator by using ____________ ______________

sodium silicate

The filtration media in a slow sand filter is _________.

unstratified

When a mechanical seal fails, leakage will come from:

Around the shaft

The double-stage process is excess lime softening is designed to:

Achieve greater magnesium removal

What are the required turbidity sampling points in a community water system?

All points where water enters the distribution system, including all filter effluents if surface water is used.

How often must sodium samples be collected by public water systems using surface water in whole or in part?

Annually

Activated carbon can experience spontaneous combustion when it is mixed with:

Chlorine compounds

A __________ sample is used to collect a coliform sample.

Grab

Chlorine storage rooms should:

Have a window in the door to allow for visual inspection without entry?

Another name for ____________ _____________ is permanent hardness.

Noncarbonated hardness

Which chemical oxidant/oxidation process is most effective in reducing tastes and odor compounds caused by the actinomycetes species of bacteria?

Peroxone

Which water quality parameter, when low, will usually cause poor coagulation, flocculation, and settling characteristics?

Water temperature

When are tastes and odors more noticeable?

Water temperature increases

What is formed when alum reacts with the natural alkalinity in water?

aluminum hydroxide

What three chemical compounds are the main contributors to alkalinity?

carbonate, bicarbonate, hydroxide

What is the term used to describe cloud formation?

condensation

In the absence of surface runoff, what can cause streams and rivers to continue flowing?

groundwater augmentation

Excess lead and copper at the customer's tap caused by unstable water comes from:

household plumbing