Useful Tools

Arsenic Removal Basics

Click here for an Adobe Acrobat file of Arsenic Removal Basics.

Water Math

This guide is intended to help water and wastewater system operators prepare for certification exams. The document Beginner Skills Check.pdf includes five sample problems that utilize each of the following skills:

• Addition, Subtraction, Multiplication & Division

• Decimals, Fractions & Percentages 

• Unit Conversions

• Area Calculations

• Volume Calculations

• Flow Rate Calculations

• Chlorine Dosage Calculations

• Pressure and Head Calculations 

For the Best Results

Start at the beginning and work as many problems as you can. You may reach a problem that you can’t work all the way to the answer, but you know some of the first few steps that you would need. Write those down. Write as many notes, formulas, conversations, etc., as you think you would need to work the problem. Then go on to the next one.

What if I Can't Work More Than a Few Problems?

Don’t worry! This is a skills check and it is designed to find your weak spots. If you get all the problems right… That’s great! If you get some wrong… now you know what you have to work on.

When you are done, open the answer key (Beginner Skills Check-answers.pdf)  and check your work. Examine your problems solving process and compare it to the example provided. Then review Formulas.pdf, which contains handy information you might need to solve the problems.

Note: You need Adobe Acrobat Reader in order to view these documents. To download a free copy of Acrobat Reader, go to:

http://www.adobe.com/

...and follow the step-by-step instructions.

Problems You May Encounter in the Skills Check Set

Here is a list of some problems you may have encountered when working in the Skills Check Set. Look over this list of common problems below and see if any seem familiar.

A lack of knowledge. You may have noticed that each group of problems is more complex than the one before it. You have to know how to add, subtract, multiply, and divide in order to work with fractions, decimals, and percentages. You have to know how to do all those things and convert units in order to find the volume of a tank in gallons.

You have to master one set of skills before you can move on. Did you see this in your results? Did you know how to solve the problems at the beginning but not at the end? Which set of skills do you need to learn first? Unit conversions? Flow rates? Identify where your first knowledge gaps are, study the formula sheet, check out the slide presentation on this site, and check out links to other water math sites. Once you feel that you’ve improved, go back and try the Skills Check Set again.

Couldn’t understand what the problem was asking. You’ve studied and you know the formulas. You can do the math, but you can’t figure out what the problems is asking you to do. This is a common problem. Maybe the problem uses terms you aren’t familiar with. Maybe English isn’t your first language and you’re facing a language barrier.

You can try a technique that helps decode the problem.

Step #1: Reread the problem and underline all the key information you are given. Underline all numbers and units. Look for clues that tell you what the numbers are for volume, pressure, and flow rate.

Step #2: Make a list of all the information you are given and sketch out the problem.

Step #3: Identify the formulas and conversions you will need to solve the problem and what order they go in.

Step #4: Do the math.

I knew what I was doing but I kept making careless mistakes. You understood the problem and you had the right equation but you hit the wrong number on your calculator, or had a rounding error, or messed up the units… This is a common problem and the test makers take advantage of it.

In the future, go back and check your answers. Once you have finished all the problems, pick a few at random and start reworking them. Don’t look at the answer you got the first time. Start from scratch and redo the whole problem. Redo as many problems as you have time for and be sure to check your units. Did you convert to the units the problem is asking for?

Useful Links

Here are some places on the Internet you can visit for more information:

New Mexico Environment Department – Surface Water Bureau Facility Operation Team Essentials
Offers a study guide for water operators. Includes a short math quiz.
http://www.nmenv.state.nm.us/swqb/FOS/Training/WSOC_Study_Guide/NM_Water_System_Operator_Certification_Study_Guide.pdf

New Mexico Rural Water Association
Offers training around the state.
http://www.nmrwa.org

New Mexico Water and Wastewater Association
Offers testing & training around the state.
http://www.nmwwa.org/

Montana Water
A free, online training course that includes water math. Requires Macromedia Flash 6.
http://water.montana.edu/training/gwb/

Pennsylvania Rural Water Association
Offers three online practice exams with answer sheet. Some questions are specific to that state, but most are general.
http://www.prwa.com/v1/training_water.htm

Kansas Rural Water Association
Offers online quizzes for water operators which include some math questions.
http://www.krwa.net/quiz/index.html

Questions? Contact Jennifer Zeyen, P.E.

Good Luck! And check back--we'll be adding more water math quizzes and tools.