Processing Magazine

Grinding industrial water-price increases lead to conservation

May 1, 2013

Where does an operations manager in a mid-sized industrial enterprise turn when water-treatment bills sky-rocket? Because make no doubt about it, that’s what they’re doing.

According to a 2012 USA Today survey of more than 100 municipalities, in the last 12 years, “water rates have at least doubled in more than a quarter of locations and even tripled in a few.” Continuing rate increases are expected of 5% to 15% every few years.

“Operations find themselves pressed to conserve water not just to relieve stressed aquifers and because water is a finite resource. It’s simply that the cost of water has skyrocketed,” Daniel L. Theobald, aka “Wastewater Dan,” principal with Environmental Services, Simpsonville, S.C., told Water/Waste Processing.

Steep consumer price increases lead to heightened scrutiny of arrangements local industries have with their municipalities. A March 27th report on the website of KTBS in Shreveport, La., for example, asked whether “big business” will see the same rate increases impacting consumers.

The KTBS report cites Pratt Industries, a local recycling company, which uses about 23 million gallons of water per month, “Companies like Pratt pay $2.13 for every thousand gallons of water they use.” With a proposed 26% increase currently on the table in Shreveport, Pratt would pay $2.68 for every thousand gallons.

Tackle uniqueness

Most all of us have been with companies that launched efforts to reduce costs and conserve resources. But there’s a big difference between dimming the stairwell lights after 4 p.m. and reducing water use in an industrial process, says Theobald. “An industrial process is a unique application and a unique treatment is needed. Moreover, as technology advances, requirements for well-managed water treatment change.”

A long-term, consistent approach to water use is difficult when people change jobs frequently or when operations are being expanded. The first step, says Theobald, “is to analyze your water usage.”

He rattles off a quick series of questions to ask. For a given process, for example, do you really need water at 100 psi for 10 minutes or would 50 psi for five minutes work as well? Further, what really are the treatment requirements? Can better use be made of timers and restrictors? What quality of water is required? City, reused, recycled?

Further, how many companies use city water to cool, let’s say, a pump and then put the discharge into the sewage system? Is that the right water to use and is that the right thing to do with the water when you’re done with it?

In fact, for the KTBS story, the city of Shreveport says it has run “grey” water supply lines to a Pratt plant where drinking-quality water isn’t needed and that it is working with the company to eventually make use of the feeds.

What to do, what to do

For the appropriate processes, companies should consider, says Theobald, using purified or de-ionized instead of city water and that a “growing number of companies use a two-step process of, first, ultrafiltration, to remove physical solids, followed by reverse osmosis, to remove dissolved solids, as a means toward water recycle and reuse. Removal of greater than 90% of pollutants and purifying 65% of the water often is possible.”

The value of good instrumentation, Theobald has learned in more than 25 years experience, is in reduced chemical usage. “You’re working with parameter set-points and ranges. If you have appropriate instrumentation and settings you can really reduce the range of operations.”

In his recent experience, Theobald has executed $2.00+/per gallon chemical use reduction from 180 to 120 gallons a day, and in another application from 80 to 40 gallons a day. The waste and over-usage is something unbelievable, Theobald says. Regulations, technology and processes all change, all the time. The water and wastewater ops in your charge may benefit from reengineering.

A final word of advice: optimize procedures before investing in new equipment.