Beware of Distribution Questions on the Treatment Exam

We just received this feedback from Subscriber Ray.  Because it is similar to observations made by many other folks, we thought we should share it with you, as a way to help you prepare for the Water Treatment exam on May 18.


Guess what? I got my D4 test results. . . I passed!!! 

That test was no joke! That was a tough one! Most of it seemed like treatment questions. Total coliform rule. Tier 1,2,3 violations. Safe drinking water act standards.  I kicked butt on the math! There was only 1 that I couldn’t get.

Thank again for all of your help. I really appreciate it.


Congratulations on passing the D4, Ray!

“Most of it seemed like treatment questions” is the phrase that struck us.  After every Distribution Operator exam, we hear that same thing.  And after every Treatment Operator exam, we hear “most of it seemed like distribution questions.”  What does this mean to you as you prepare for any water system operator certification exam?

There is a lot of overlap between treatment and distribution.  It is wise to study both as you prepare for a certification exam, because you will probably find exactly what Ray found.  Make sure that once you’ve gone over all your treatment study materials, you go back through your distribution notes too.  Expect to see a few questions on pumps, valves, and corrosion that you would have thought only showed up on distribution exams.

Also notice that Ray nailed the math portion of the exam.  You can too!  Don’t pass up our offer to get all nine of the MOST Water Math courses on DVD for only $50.  Over ten hours with over 100 typical water math problems worked out step by step in a simple, easy to understand format.  Be confident that you can answer the math questions on the certification exam!  Click on the Contact link at the top of our home page, and let us know you would like the MOST Water Math DVD.  We’ll send you the ordering information.

Then you can send us an e-mail like Ray, letting MOST know that you passed your certification exam!

2 Responses to Beware of Distribution Questions on the Treatment Exam

  1. avatar Chad says:

    Don’t pass up our offer to get all nine of the MOST Water Math courses on DVD for only $50.

    How do I get this?

    • avatar MOST says:

      Unfortunately, we don’t have a direct purchase option on the MOST site for the Water Math DVD. To get this DVD, contact us directly by clicking on the “Contact” link at the top of our home page, or send us an e-mail at In the e-mail, let us know you want the MOST Water Math DVD and give us your mailing address. We’ll then send you the instructions on how to pay us through PayPal, unless you are already a PayPal pro, in which case you can just send the $50 directly to “MOST Water Training”. Once the payment is received we’ll mail the DVD. Thanks, MOST

Leave a Reply

Your email address will not be published. Required fields are marked *