Operator Math

The measure of all things, including their performance

• By Jerry Grant
• Jan 15, 2008

Why is operator math necessary? It is needed to evaluate how well a plant is performing, or what the plant is capable of treating adequately. State authorities consider the topic important enough to include at least a little math on even the lowest level certification exams because solving these problems can help answer:

• Is the plant performing satisfactorily?
• Why is the effluent not meeting permit limits?
• Are various units adequately sized for their respective flow or organic load?
• Is the entire plant overloaded?
• Does the plant have plenty of reserve capacity?
• Would treatment be adequate if a clarifier were taken out of service?
• What amount of sludge should be wasted?
• What should be the setting on a chemical feed pump?

A certified operator is a professional operator and, as a professional, should be capable of mastering this part of the profession. Everything in a wastewater treatment plant -- from pumps to chemical feed rates to adequacy of design -- can be determined with basic arithmetic. But learning the math does not have to be that difficult.

A good approach
I have worked with operators for 40 years and have developed some ideas on how to approach the task.

1. Watch what you tell yourself.

Many times operators have told me, “I’m dumb in math” or "I just can't pass the Class III exam."

This is a destructive form of self-talk and often turns out to be a self-fulfilling prophecy. On a subconscious level, these statements become a kind of core belief. You can do the math; it just takes practice and preparation. Self-confidence in any area is a matter of practice until you become proficient.

2. Attend operator training workshops and seminars.

These short courses usually have a math session. If you are counting on being proficient after one hour of workshop training, forget it. You need more practice. These training sessions, however, can be helpful in your basic understanding of operator math.

3. Attend long-term classes.

Many training providers have 16- to18-week courses in wastewater treatment or wastewater collection. These courses are an excellent opportunity to learn basic math, since you have a whole semester to practice and can receive help from an instructor. In addition, you may receive college credit toward an associate degree.

4. Obtain a good basic math book.

The best way to learn math is to study a little bit every day. Solve a problem every night after supper. Can’t get it?  Keep working until you understand what you did wrong. Making a habit of daily study is the true road to proficiency.

5. Do a good job of preparation.

If you are taking a certification exam, begin studying several weeks ahead of time. Be calm. Fear, anxiety, frustration, or anger will sabotage your thinking processes. Studying in advance will help you be much more confident.

These tips should help with the math you need for certification exams but, more importantly, they should help you with your basic understanding of plant processes.

The same advice is applicable to all areas of knowledge in wastewater treatment and collection. Preparation is the key.

BC (before calculators)
In the late 1960s, when I began my career, the electronic calculator was not available and calculations were made using manual arithmetic operations.  Many operators at that time were older and had been out of school for years or even decades.  Pencil and paper calculations were difficult for them, as were the concepts of organic and hydraulic loading, flow, etc.

In our state, the Class III and Class IV exams had a few math problems that had to be solved manually. Calculation errors made correct answers fairly rare, but an operator could get partial credit for setting up the problem correctly. If a Class III or IV exam had three or four math problems worth five points each, the operator needed at least partial credit on some of them to have a good chance of passing.

After-calculator era
Calculators began to be widely available in the early 1970s, relieving operators of laborious manual calculations. A few more math problems were added to the exams and the exam format eventually went 100 percent  to multiple choice/true-false. Exams could then be machine- graded. Math problems, however, were worth only one point. For problems with several steps, an operator could elect not to use his/her time on calculations and merely pick one of the answer choices and move on.

With the use of calculators another problem was noticed—operators tended to read the problem and immediately begin pushing buttons on the calculator, hoping to come up with something close to one of the answers. Logical organization of the problems was neglected by many exam candidates. Calculator or not, organization of the problem should be done before doing the calculations.

The types of math problems became somewhat more sophisticated. Before the Clean Water Act, most of the wastewater treatment in small communities was done with Imhoff tank-trickling filter plants, and waste stabilization ponds were becoming very common.  In later years, water quality-based permits became widespread with particular attention to ammonia levels in the effluent. As a result, many more activated sludge plants were built. The math needed for control of the activated sludge process, SVI, MLSS, MCRT, SRT etc., began to show up on higher-level certification exams. Horsepower and energy problems became a staple on advanced level exams.

Computerized Operations
With the advent of SCADA systems and computerized operations, laboratory data is entered and the calculation made by the computer for many different parameters. Newer operators training in these facilities are not likely to learn or retain basic math concepts.

In summary, math has always been and will continue to be one of the hardest parts of the operator’s training. The keys to success are preparation and practice. Many opportunities for advancement will become available as older operators retire. The person who prepares will be the one who advances in this great career field.