Programmable Logic Controllers Offer Automation Solution For Water Utilities

Water utilities are on the lookout for ways to increase automation at treatment plants but some experts say they are lagging behind other industries in how they incorporate new solutions.

Just ask David St. Pierre, who went from a career around oil refineries to one in water utilities in 1986. St. Pierre is executive director of the Metropolitan Water Reclamation District of Greater Chicago (MWRDGC) and vice president of the National Association of Clean Water Agencies (NACWA).

“The difference between making gasoline and controlling water is night and day. It was like taking a step back in time,” he told Automation World.

“We have to figure out how to implement true automation in water,” St. Pierre said late last year. “In each city that I go into, they really aren’t applying normal control strategies, which have been tried and true for ages. I see programmers that are starting from scratch on a blank sheet of paper, trying to recreate control systems that already exist in the systems that they’re buying.”

One new product available in this space claims it increases automation while also cutting costs and energy requirements at water treatment plants. The product, from Pleasant Mount Welding, is a custom programmable logic controller.

"The systems can link to probes to actively monitor pollutant levels and other water quality factors and easily generate reports for regulatory agencies,” The Scranton Times-Tribune reported. “The company plans to market it in conjunction with sequencing batch reactors, which engineer David Klepadlo described as an advanced treatment system that uses bacteria to consume contaminants in one tank. The system is cheaper to build and maintain than traditional plants that use a similar process in multiple tanks.”

"For example, building a traditional 400,000-gallon-per-day plant would cost $4 million, compared to $2 million for a new sequencing batch reactor plant and $1 million to retrofit an older plant, the company estimates,” the report continued. “The system can also can cut energy costs in half and is designed to help facilities comply with newer environmental regulations, such as the push to reduce nitrogen levels prior to discharge into waterways."

Company President Bob Non spoke to the Times-Tribune about the product.

“In the old days, it was mechanical timers that you used,” he said. “Now you’re dealing with automation. We can log in from our office here and see what’s going on remotely. If there’s any issues that come up, we get texts. We get email alerts. We get all that information. These plants basically can run on their own.”

Security concerns are a major reason why some water utility managers are hesitant to pursue greater levels of automation, according to a report on the state of the water industry by engineering company Black & Veatch.

"In some cases, the question of cost is joined by concern over the perceived encroachment of automation technology. Some utilities are unwilling to embrace cloud computing — where analytics can really flex its muscle by quickly collating, processing and presenting massive amounts of data — because of security concerns. Managers may also fear that data analytics and other automation technology could ultimately reduce the labor force and at least partly remove human intuitive decision-making from the operational equation," the report said.