How to Conquer Your SCADA Trust Issues

SCADA is great in many ways. However, you still need to confirm the system is doing what it says it's doing. Here's how one operator conquered his trust issues.
How to Conquer Your SCADA Trust Issues
A great example of the plant overview. Operators can see all major data points in moments before heading out to do a more complete round.

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I’ve worked in the same plant for 30 years, so I've witnessed the years of “stay out of sight” — meaning be invisible and nobody will know we exist — to the modern-day “let’s show off what we do and how we do it.” In that time, our industry has changed greatly. Municipal jobs used to be where people came to retire, but today we have too much responsibility to be a home for those riding out their last few working years. We need licensing and we need training to keep up with ever-changing technology. Our permits require this of us, and the public expects this of us.

Technology gives us that ability.

When I started in this industry, I learned how to operate everything from pumping stations to the collections system to the actual plant. Although the flow process is still pretty much the same, we now have the ability to know what is happening at a plant in real time.

The introduction of SCADA
Today, SCADA provides real-time streaming data. I can sit at a computer, and in less than 10 minutes, have a very good understanding of how my process is running. I can log in remotely from my iPhone or iPad. I can log in to plant cameras to see tanks and visually inspect the grounds as well as take pictures of people, places or things.

When it comes to SCADA, you have to trust it, which isn’t always easy. At my plant in Billerica, Massachusetts, we’ve found that SCADA doesn’t always tell the whole truth. Oh, don’t get me wrong; SCADA is great in many ways. Thanks to SCADA, I can see an overview of my plant and know if there is a problem in a moment’s notice. However, I still need to confirm the system is doing what it says it’s doing. For instance, SCADA might tell you a chemical pump is running, but it might not tell you if it’s delivering the chemical to where it is supposed to go.

I use alum, and recently, the SCADA system said it was pumping at 179 mL/min to our reaction tank. However, my pH probe at that location said otherwise. Usually pH drops when alum is added to the process, but in this instance the pH was nearly unchanged. How? SCADA said my pump was running, and it appeared chemical had been used in the past 24 hours. As it turns out, the chemical line was blocked, and the chemical was recirculating back into the chemical tank. The chemical splashing gave SCADA a false number on tank volume. We caught it and cleared the line, started the pump back up, and within 10 minutes the pH dropped.

It’s because of things like this that we’ve developed specialized SCADA checklists. We scan the entire plant on SCADA, but now we watch pump speeds and volumes and check for regular pumping patterns. After our SCADA scan, we go out into the process, walk the plant and use our senses.

Combining this knowledge with what you’ve seen in SCADA should make for a trouble-free round. Today, operators need to be analysts, technicians and detectives. Operators need to analyze SCADA screens and then understand what the screens indicate. When trouble arises, we use our Historical Trends Page to see what happened and when it happened.

Your plant is full of many moving pieces, and SCADA can send you data on all of it.  But without the above-mentioned skills, you won’t make the best decisions on how to run your plant.

Soaking in the benefits
At my plant, operators spend a fair amount of time maintaining SCADA data points in the plant. We calibrate pH probes twice a week, maintain the turbidity probe and pump out chlorine basins weekly. We rotate our chemical feed pumps weekly. We even change the suction lines on filter feed pumps, RAS pumps and WAS pumps. We’ve started a great oil and grease program, and we try to involve all operators in all phases of work within the plant. The operators' overall knowledge of the plant is very complete. SCADA has allowed for a lot of cross-training, and the benefit is that the plant is running better than ever.

We’ve eliminated our off shifts and brought everyone onto first shift without layoffs. We now have a call person who carries an iPad. When SCADA detects a problem, it dials out and the call person can respond. Usually the fix is made right from the iPad. We’ve also done this for our collections system, which has resulted in better-maintained equipment and better overall understanding of process and equipment.

SCADA does work and will create almost instant results if you set it up correctly, train people and get everyone involved. We are proof of this.

About the author
Jeff Kalmes is a Grade 7 operator and plant supervisor at the Town of Billerica Wastewater Treatment Plant. He has won the 2008 NEWEA Public Educator Award, the 2011 WEF National Public Educator Award and the 2015 NEWEA Operator of the Year Award. You can reach him at jkalmes@town.billerica.ma.us.



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