January 2023
1. Calculate the chlorine demand using the following data
• Raw water flow 0.75 MGD
• Chlorinator feed rate 4.0 mg/L
• Chlorine residual is 1.8 mg/l
a. 0.8 mg/L
b. 2.2 mg/L
c. 4.0 mg/L
d. 5.8 mg/L
2. Covert 60.5 degrees Fahrenheit to degrees Celsius
a. 15.8 degrees C
b. 20.6 degrees C
c. 72 degrees C
d. 101.2 degrees C
3. Calculate the drawdown, in feet, using the following data:
• The water level in a well is 20 feet below the ground surface when the pump is not in operation
• The water level is 35 feet below the ground surface when the pump is in operation
a. 15 feet
b. 20 feet
c. 35 feet
d. 55 feet
4. How many pounds of a chemical applied at the rate of 3 mg/L are required to dose 200,000 gallons?
a. 3 lb
b. 5 lb
c. 16 lb
d. 50 lb
5. Calculate the average weekly flow for a system with the following data
Sunday – 3000 gallons Monday – 4000 gallons Tuesday – 3,500 gallons
Wednesday- 2,000 gallons Thursday – 3,000 gallons Friday – 3,500 gallons
Saturday – 2,000 gallons
a. 2,000 gpd
b. 3,000 gpd
c. 4,000 gpd
d. 5,000 gpd
6. A 50-pound container of calcium hypochlorite contains 65% available chlorine. How many pounds of available chlorine does it contain?
a. 76.9 pounds
b. 32.5 pounds
c. 17.5 pounds
d. 2.5 pounds
e. 2.5 pounds
7. Primary Clarifiers remove:
a. Dissolved solids
b. Inorganic solids
c. Settleable solids
d. Total solids
8. You get a sudden increase of organic material to your treatment plant. What steps should you take to make sure that adequate treatment is maintained?
a. Chlorinate the return sludge and the influent
b. Decrease the aeration and waste more sludge
c. Increase the return rate and add supernatant
d. Increase the aeration and increase the return rate
9. In a series circuit, if one unit is burned out or disconnected the other units will
a. Become overloaded
b. Cease to function
c. Continue to function
d. Continue to function until the failed unit is replaced
10. One type of positive displacement pump is:
a. Peristaltic pump
b. Radial flow pump
c. Air lift pump
d. Axial flow pump
Associations Offer In-Person Training
There are many benefits of online, virtual training: reduced costs, time-savings, greater flexibility and accessibility. Many people, however, are more comfortable and have better retention when they are in a traditional classroom setting with a live instructor. They find it easier to focus, ask questions, and interact with other attendees. To that end, here is a list of upcoming in-person training sessions and live conferences. Make sure to contact the organization to determine their attendance policies. And be on the look-out for the monthly training calendar that is emailed to all certified operators that contains both virtual and in-person options (also available on the DEP website: https://www.maine.gov/dep/water/wwoperator/ (under Additional Material).
MRWA Training – For more information or to register, go to www.mainerwa.org or contact Andrew Snowman at andrew.snowman@mainerwa.org. or call 207.530.6073
• Road Opening Permits – BMPs, 1/4/23, PUC Building, Hallowell
Overview of rules & regs you need to know before breaking ground for planned or emergency utility repairs.
• General Service Work, 1/13/23, EJ Prescott office, Bangor
Drilling and tapping water and sewer mains, valve insertion, pipe and valve location, leak location, maintenance, and pressure testing.
• Wastewater Cert. Exam Prep (I and II), 1/17-1/19/2023, Kennebunk Sewer Dept. (KSD)
For biological, physical, and chemical treatment for operators preparing for levels I and II exams. The seven examination core competencies along with the exam questioning formats will be discussed based on the ABC 2008 Need-To-Know Criteria. Use of the 2017 Formula/Conversion Table for Wastewater Treatment will be discussed throughout the class. Participants will learn test preparation, study tips, along with test time management will be beneficial to testing successfully.
• Wastewater Cert. Exam Prep (III – V), 2/14-2/16/2023, Brewer Sewer Dept.
This certification exam prep class will focus on advanced biological, physical, and chemical treatment for operators that are preparing for Levels III, IV, V exams.
• HDPE Pipe, Fittings, and Fusions. 3/14/23 and 9/14/23, EJP Bangor
Intro to HDPE pipe and fittings. An overview of fusion techniques: butt fusion, electrofusion, saddle fusion, and others. Type of fittings and components. How to select and work with HDPE fittings in a piping system. Technology updates.
• GIS/GPS Applications, 5/11/23, EJP Bangor
Participants in this workshop will learn how digital mapping and GPS tools can be used in managing rural water and wastewater systems.
JETCC/NEWEA – To register: https://jetcc.org/index.php.
Collection Systems Exam Prep, 1/4-1/5/2023, Portland
This two-session, 12-hour in-person course is intended for those preparing to take Grades 1 through 4 of the NEWEA Collection Systems Certification exams. Participants will receive instruction on collection system operation and maintenance (O&M), including but not limited to the purpose of wastewater collection, wastewater flow characteristics, collection system components; pump stations, system maintenance and inspection; pipeline rehabilitation, and collection system safety. The course will also review math concepts and provide example problems for exam preparation. Attendees must bring a calculator. Important note: Certification exams are now administered only by NEWEA. This course does NOT include the exam.
MWUA Training – go to https://mwua.org/training/ to register.
• Real-World Chemical Feed Pumps, 2/28/2023, Bangor and 3/1/2023, Portland
Water treatment is a crucial and everyday task with which most systems must contend. Treatment chemicals must be dosed correctly, otherwise, the health of the public, environment, system, and more can be significantly affected.
Join MWUA and Ti-SALES as we take a deep dive into everything chemical feed pumps. From the types of pumps, to how to choose the best pump, to tips, tricks, and accessories to improve your chemical dosing; this presentation is perfect for anyone new to chemical feed pumps or those simply looking for new solutions! Don’t miss out! Whether you're new to the industry or a seasoned professional, there's something for everyone. Free breakfast, coffee, and refreshments will be provided to all attendees.
Upcoming Conferences
NEWEA 2023 Annual Conference & Exhibit
NEWEA is excited to connect in person with our water industry colleagues at the 2023 Annual Conference & Exhibit, taking place at the Boston Marriott Copley Place, Boston, MA, January 22-25, 2023. The NEWEA Annual Conference is a great forum to meet colleagues, professional allies, make new friends and exchange information.
This prestigious conference, which consistently attracts over 2300 engineers, consultants, scientists, operators and students features a variety of technical sessions and over 200 exhibitor displays. The conference provides an opportunity for professional exchange of information and state-of-the-art concepts in wastewater treatment and other water environment issues.
For more information, go to the NEWEA website, https://annualconference.newea.org.
MWUA’s 97th Annual Tradeshow & Conference – Looking Ahead
MWUA’s 97th Annual Tradeshow and Conference will be held on February 1st and 2nd, 2023 and will be hybrid/in-person at the Augusta Maine Civic Center. The event is Co-Sponsored by MEWEA .
Go to www.mwua.org or contact Cindy Wade at cwade@mwua.org for more details.
The North Country Convention (NCC) Returns to Presque Isle!
Mark your calendars for the North Country Convention (NCC)’s return to Northern Maine Community College (NMCC) in Presque Isle on April 5 & 6, 2023.
This 2-day educational event and trade show held in "The County" is co-sponsored by NEIWPCC-JETCC, MEWEA, and MWUA. NCC is designed to bring water and wastewater professional together for technical sessions, exhibitor interaction, luncheon speakers, and opportunities to network with others. Each day offers 6 training contact hours for Water and Wastewater operators. Participation in the entire conference offers 12 hours of training.
For more information, go to www.jetcc.org.
Certification Update
Odd-Numbered Certification Renewals March 1, 2023
Now is the time to prepare for your 2023 renewal by completing any needed continuing education training and renewing your certification. If you have moved, contact the NEIWPCC South Portland office to ensure you receive important renewal notices.
Use this link to renew your certification online, check your TCHs, download forms, and read the certification policy:
https://jetcc.org/wastewater-operator-renewal.php
For more information on how to renew your certification, contact Spring Conolly at 207-253-8020 or email certification@neiwpcc-jetcc.org.
Refer to the Department’s Wastewater Operator Certification Program website for details on certification renewal requirements: https://www.maine.gov/dep/water/wwoperator/.
Monthly Training Calendar
Every month the DEP emails to certified operators a list of upcoming training opportunities offered by non-profit organizations. The email also includes DEP-approved On-Demand classes taught by both public and private training providers. These lists are found on the DEP website, https://www.maine.gov/dep/water/wwoperator/ (under Additional Materials). The website also lists DEP training policies, forms, and other resources.
For more information, contact Judy.K.Bruenjes@maine.gov.
To generate valid and defensible data labs must incorporate appropriate QA/QC practices into the routine operations at their facility. This can seem like a daunting task, one that is complicated by terminology that can be easily confused or misunderstood.
Many test methods require the routine analysis of replicate and/or duplicate samples. These terms are sometimes used interchangeably, while they are similar there are some important distinctions that are worth noting.
A replicate is a sample that is divided into subsamples after collection. The subsamples are analyzed and the results are compared to assess laboratory measurement precision. Some methods specify criteria for how close replicate analysis results must be, if the method does not give criteria then the lab has to generate their own criteria using internal QC data.
A duplicate is a sample that is collected at the same location and time as another sample, each in individual containers. Comparing the results of duplicate analyses not only assesses laboratory measurement precision but also includes the additional uncertainty due to sampling procedures.
The term precision mentioned above is often mentioned in conjunction with accuracy. Both are important when assessing the validity of laboratory data.
Precision refers to the repeatability of test results in your laboratory. An analogy that is often used is that of a dart board, if your lab results have good precision your darts will all be close to one another on the dart board, but not necessarily close to the bullseye. See the figure below for a visual representation of accuracy and precision.
Figure 1: Precision versus Accuracy
 As mentioned before, replicate analyses are one way to monitor your laboratory’s precision. There are several ways to calculate analytical precision, one of the simplest is finding the percent difference between the 2 numbers. To calculate the percent difference of 2 replicate values, subtract the lower value from the higher value, divide this number by the average of the 2 replicate values, then multiply this number by 100 to get the percent difference.
Once you have this number, knowing what to do with it is the next step. Some methods give criteria for replicate analysis results, for example SM5210B for 5-day BOD test specifies replicates should be within 30%. If the percentage difference between 2 replicates is greater than 30% SM5210B says to identify the results on the report as not meeting quality control criteria. Basically, the result is determined to be unreliable due to low precision. In this instance it would be a good laboratory practice to evaluate all steps of the test procedure to identify potential causes for the low precision. It could be something as simple as the analyst forgetting to put in a reagent or using the wrong amount of the sample; but it could also be a larger issue that requires a corrective action, such as contaminated dilution water.
An example of this calculation with actual data could be replicate 1 result of 221 mg/L and replicate 2 result of 176 mg/L:
High Result minus low result (Replicate Difference): 221 - 176 = 45
Average of replicates: (221+176) / 2 = 198.5
Replicate Difference divided by Average times 100: (45/198.5) * 100= 23%
Therefore, replicate results of 221 mg/L and 176 mg/L for the BOD test would be acceptable using criteria found in SM5210B, since the percentage difference is less than 30%.
Accuracy shows how close your results are the to the bullseye. Accuracy is assessed by analyzing a sample with a known value and comparing the results to established acceptance criteria for the known sample. Analysis of the DMR-QA samples is an example of using a sample with a known concentration to determine the accuracy of a test method. Certified reference material (CRM) can be used on a more frequent basis to monitor laboratory accuracy. CRM, also commonly referred to as QC Standards, are available from most proficiency test providers and come with a certificate of analysis showing the acceptable range for results. These standards can be analyzed weekly or monthly to verify the analytical method is being performed with the appropriate level of accuracy.
While there are other elements necessary to ensure valid data, routine monitoring of your laboratory’s accuracy and precision is an integral part of laboratory operation. Monitoring these results can be particularly useful in helping to spot trends that indicate potential problems before they become major issues. Control charts are a very useful for identifying trends in data for both replicate and QC standard analyses.
Generating valid data is a primary goal of any laboratory. There are many tools available to customize a system that works in your laboratory. If you would like more information on incorporating additional QC measure into your laboratory please contact DEP technical assistance, Brett Goodrich 287-9034 or Brett.A.Goodrich@maine.gov.
1. b. 2.2 mg/L
Chlorine demand = Chlorine dose (mg/L) – Chlorine residual
4.0 mg/L – 1.8 mg/L = 2.2 mg/L
Note that the flow doesn’t enter into the calculation
2. a. 15.8 degrees C
Degrees Celsius = (Degrees Fahrenheit – 32) * (5/9)
Degrees Celsius= (60.5 -32) * (5/9)
degrees Celsius = 15.8
3. a. 15 feet
Drawdown = Pumping water level – static water level
Drawdown = 35ft – 20ft = 15ft
4. b. 5 lb
Chemical Dosage = Chemical concentration, mg/L * MGD* 8.34, lb/gal
First convert 200,000 gallons to 0.2 MG
Dosage = 3 mg/L * 0.2 MG * 8.34 = 5 lb
5. 3,000 gpd
Average= (Sum of all terms)/(Number of terms)
Average= (3000+4000+3500+2000+3000+3500+2000)gallons)/7
Average= 21,000/7=3000 gallons
6. b. 32.5 pounds
Part/Whole X 100=%
Part/(50 lbs)= 0.65
Part = 0.65 X 50 lb
32.5 lb
7. c. Primary clarifiers are designed to remove solids that easily settle from the wastewater stream
8. d. Organic matter is food for the microorganisms (bugs) in the system. In order for the bugs to properly assimilate that food, they must have adequate oxygen and there must be enough bugs. Increasing the aeration will help ensure the proper amount of oxygen and turning up the return sludge rate will provide additional bugs.
9. b. In a series circuit, the units follow one another along one path. If one unit burns out, the path is broken and no electric current can flow, therefore all the units will cease to function
10. a. A peristaltic pump works by constricting the size of the tubing holding the fluid at certain points which forces the fluid to flow
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