When should membranes be cleaned?
When pressure needed to operate at rated capacity increases by 15% or product water flow decreases by 15%.
When must the Consumer Confidence Report be reported?
Delivered via mail to each billing customer by July 1". (62-550.824)
When must the Monthly Operation Report (MOR) be submitted to the local DEP or HRS office?
Within 10 days after the month of operation. (62-550.730)
According to Statute 62-550 what is a cross-connection?
Interconnection between two water systems is ok. Connection between an approved water source and an unapproved water system is an example of a cross-connection. Cross-connection prohibited.
What is a sign of a cross contamination that your customers would call to complain about...
Musty Septic smell
According to the Lead and Copper Rule what best describes the process for taking a "First draw" sample?
Take sample from bathroom sink that has been unused from 6-8 hours.
Please describe from top to bottom the layers of a multi-media gravity filter that most often are used.
Anthracite coal, sand, garnet.
Tuberculation in iron pipes is common example of corrosion in the distribution system. Tuberculation decreases, the carrying capacity of water mains, increases water quality complaints, and increases electric costs for pumping water due to the diminished carrying capacity of the mains.
N/A
The greater the C-Factor...
The smoother the pipe.
What factors are needed to calculate the Langelier Index?
Water temp, TDS, Alkalinity, Ca hardness, and PH of POE.
How long must you keep records for?
MOR's - 10 Years, Bacteriological - 5 Years
What is the best way to measure the effectiveness of a WTP's processes?
Turbidity
What is most likely the cause of a medicinal taste in water?
Phenols
A customer calls and complains that when they filled a glass at sink it is cloudy. What can you determine?
Ask customer to see if it clears up which would mean air or if particles settled at the bottom.
What is the lowest the psi may go in distribution system?
20 PSI
What is Thermocline?
Middle Layer of Lake or reservoir that lowers in temp as the depth
increases.
Question regarding tube settlers and their functions in a package plant.
Installed to help in the efficiency of the sedimentation process/
Raw influent quality of water has diminished and beginning to see plant effluent diminishing. What can be done to correct problem.
Increase mixer speed
Decrease poly dose by 1-2mg
How long can a THM sample be held before analysis?
14 Days
What will break down ion exchange resin?
Chlorine
When an ion exchange resin bed is saturated with calcium & magnesium, what mineral is used to regenerate the bed?
Brine
If thiosulfate is not added to a THM sample what could happen to the sample? All sample jars for testing Total Trihalomethanes must contain a chlorine reduction agent (Sodium Thiosulfate). To test for potential THM, you do not put a chlorine reduction agent in the sample jar.
THM formation would continue
How often are THM samples required to be taken?
Water systems serving more that 10,000 people must test for THM once each quarter. Less then 10,000 are once a year.
As the source water temperature and PH increase, THM formation?
Increases
What is a valve commonly used to control flow?
Globe valve
When analyzing a 100ml sample of water for alkalinity it took 1.3 ml of 0.02 n sulfuric acid to reach a ph of 8.3 and a total of 10.5ml of titrant to reach a ph of 4.5. What is the p and total alkalinity?
13P 105T
130P 100ST
The plant flow is 7.5 MGS. The treatment unit is 70' long, 20' wide, and 10' deep. What is the detention time in minutes?
20min
Disinfection is best accomplished when what conditions exist?
High concentration and long contact time.
A WTP using lime softening process has a finished water hardness of 82 mg/l and a +0.5 LI what is the water condition?
Finished water is scale forming
Many samples for MCL compliance are taken in the distribution system. Which sample is taken where the water enters the distribution system?
Color
What is the primary purpose of filters in a wtp?
Lower turbidity
Question regarding ....To control THM formation, alternate disinfectants are used including ozone, chlorine dioxide, and chloramines.
N/A
When taking a hardness test, the titration should be completed within 5 minutes. An inhibitor reagent should be used when metal ion interference causes an indistinct end point and a sample volume should be selected which requires less than 15 ml of EDTA titrant.
A specific question on test explains that titration is not showing an indistinct end point which the answer I chose was to use larger sample in order to show this change clearly.
Determine break point chlorination point using the following chlorine analyses.
Which one of the following conditions will lead to a smaller number of THMS forming?
Options:
a. High water temperature
b. High ph
c. Low ph
d. High chlorine concentration
Just changed raw water flow what should you do?
Record flow change - I answered
To remove magnesium, a WTP is using excess lime and recarbonation. What method can you recommend to lower their treatment costs and maintain the water quality?
Split treatment
THM precursors are?
Naturally occurring organic compounds
Question regarding Iron and manganese react with chlorine to form insoluble compounds.
N/A
The minerals that cause hardness in water are precipitated out as?
Calcium carbonate & magnesium hydroxide
Question regarding the Electrodialysis (ED) treatment. What is false about it?
Most of organic compounds are removed
To precipitate the hardness from the water, the pH must be lowered considerably or the finished water will be extremely scaling. The two most common methods of handling this problem are:
Recarbonation
Split treatment - cheaper
What can be said about quicklime?
Needs to be slaked
What is the MCL for iron?
.3
Know the definition of tubercles
The filter head loss at the start of a filter run is one foot. The design head loss is 10 feet. How many additional feet would you allow before backwashing the filter?
When head loss reaches an additional 8 or 8 and half feet totaling 9 or 9.5 head loss.
What is an example of a good preventative maintenance program?
Training program
Question regarding what is not a purpose of a clear well or ground storage tanks?
Options:
a. Provide water storage for peak demands
b.
Provide proper disinfection time
Question asking to what are examples of disease causing bacteria that may be transmitted in the water....
N/A
Question instructing you to give the average THM with eight samples given.
Add the eight samples and divide by eight
What is the correct method to determine the hydroxide alkalinity in the lime softening process?
2P-T alk
Lime also increases the alkalinity of the water. The calcium and magnesium hardness form insoluble precipitates as the pH of the water continues to increase. The slaked lime converts the bicarbonate alkalinity of the water to carbonate alkalinity and allows the insoluble calcium and magnesium hardness to precipitate of the water.