INDUSTRIES: Water and Wastewater Reaps Unintended Consequences

"It's never a dull day. That's life now in the water and wastewater-treatment industries," remarks Rebecca West, deputy general manager of technical and engineering services for Spartanburg (S.C.) Water (www.sws-sssd.org).

Aw 1859 1005 Indust
"We're looking, as never before, to find ways to optimize processes." That involves even discontinuing some treatment processes because of reduced demands, she adds.

But lower wastewater flows and decreased potable water use by business happens "faster than ever," West observes. Some drivers include, for example, loss of businesses, restaurants not washing as many dishes because fewer people dine out, people using smart irrigation and consumers using low-flow toilets. "We want them to do these things, but it's creating loss of business for us." She comments that these types of reductions have caused an overall 10 percent loss in utilities' revenues across the United States.

Those recession- and/or conservation-related reductions produce other unintended consequences. At some wastewater treatment plants, it means higher influent solids loading with lower flows. "That's causing some change in the treatments," West comments. More septic waste streams, caused by those lower flows, can require more energy-intensive treatment, she adds.

Nonetheless, to dampen its economic losses, West believes the industry will move toward more instrumentation and monitoring to predict changes in pretreatment and treatment processes. "For sensitive systems where, for example, advanced nutrient removal is required—these systems especially need to have advanced knowledge of what's happening in the system," she explains.

The industry does try now to get that advanced information by learning to use what they have and taking advantage of newer technologies. For example, oxidation-reduction-potential (ORP) monitoring helps plant operators determine appropriate influent disinfection doses. Supervisory-control-and-data-acquisition, or SCADA, systems facilitate real-time analysis of data. "That's so operators can have the information, to understand what the data mean, how to interpret it and how to make decisions with it," West explains.

Inflow and infiltration problems persistently require attention, too. But they're longer term, West says. "It's a challenge of aging infrastructure, of trying to replace and repair." Aggravating the problem is inadequate systems design, including stormwater systems tied into wastewater-treatment systems that were never meant to handle the additional, large-volume, infrequent flows.

Stimulation needed

Paul Miller suggests that the stimulus funds authorized by the U.S. Congress more than a year ago could help, by spurring project activity through a funding mechanism called state revolving funds. However, "the reality is that these [billions of dollars of] federal stimulus funds just represent a drop in the bucket relative to the total amount that will be required to thoroughly overhaul the crumbling U.S. water and wastewater infrastructure," remarks Miller, the lead global-water-quality-and-wastewater-industries analyst for ARC Advisory Group Inc. (www.arcweb.com), Dedham, Mass.

Miller sees at least one other recession-related negative effect on the industry. "Always-conservative municipalities tend to be slow at implementing new technology solutions during the best of times," he observes. "But the initial impact of the recent economic crisis was to squeeze state and municipal budgets to the breaking point—and beyond—which initially put many planned and desperately needed capital-water and wastewater-infrastructure projects on hold."

The core of the problem is that the capital cost of water infrastructure replacement, combined with high operating-and-maintenance costs, far exceeds the financial capabilities of many municipal water utilities, Miller relates.

West agrees that much more money will be required, even though she notes that the economy is "coming back some," and there are "some impacts from the stimulus funding. But that [combined effect] is small." What isn't small, though, is the need for use of controls and automation. As she says: "That will become even more critical because of the nature of our business."

C. Kenna Amos, ckamosjr@earthlink.net, is an Automation World Contributing Editor.

Spartanburg (S.C.) Water
www.sws-sssd.org

ARC Advisory Group Inc.
www.arcweb.com

Subscribe to Automation World's RSS Feeds for Columns & Departments

More in Control