Cold-Weather Operations Require Foresight and Special Precautions

Maybe it’s because so many water and wastewater treatment plants are located in sunny climes, but cold-weather operation doesn’t seem to get headlines. It should, because plants in the Frigid Zone need to take special steps to get through winter. 

Bill Sheehan, of the Maine Department of Environmental Protection, stresses preparation. Sheehan says he’s a “bit of a nag” when it comes to reminding plant operators to spend a pre-winter day walking around the grounds looking for potential issues. 

“Lots of facilities are small — some are one-man shows,” Sheehan says. “It’s very easy to overlook winter prep stuff and get caught by surprise. Problems can snowball and cause additional difficulties throughout the winter.” 

Plan for snow removal and operator safety, he says. A man down because of slips from snowy roofs or ice-covered ladders can lead to operational shortcuts and compliance issues. “Shovel that snow for clean water,” Sheehan advises. 

And stake and mark low structures. “I have seen curbing, gear boxes, hatches and even an entire pumping station cover trashed by a snow removal loader in an instant,” Sheehan says. 

“In the spring several months-worth of precipitation can be released in a thaw and this water needs an unobstructed path to avoid flooding,” he continues. “Culverts crushed by snow removal equipment and drainage obstructed by trash hidden under the snow has led to minor but costly floods and access road damage at area facilities.” 

At Ishpeming, in Michigan’s Upper Peninsula, lead operator Paul Altobello says his wastewater team follows several steps when winter arrives. His advice:

  • Conduct an annual safety meeting on winter safety, shoveling, heart attacks, back injuries, slips and falls.
  • Service and test run all your winter equipment like snow blowers, plows and loaders.
  • Get the shovels out and have a winter’s supply of sidewalk salt at all the main entrances.
  • Drain any equipment gearboxes that accumulate condensate before a deep freeze occurs. 

Ishpeming runs service water all winter long to keep stand-alone tanks from freezing and damaging skimmers and other equipment. 

Homer, Alaska — about as far north and west as the continental United States gets — takes special steps to get ready for cold weather, even though much of the operation is indoors. 

Water and Wastewater Superintendent Todd Cook says local regulations help the city plan for winter weather. “We order enough chemicals in the fall to make it to late spring/early summer because when the highway is thawing out, the state institutes load limits which means it takes more deliveries to get the same amount of chemical on site,” he says. “We would end up paying more for shipping.” 

Homer also looks ahead. “We pull the aerators and dredge out of the pond before they get frozen into the ice,” explains Cook, “and we service them now so come break up they’re ready to drop back in the pond.”

Special attention to lagoons and ice cover is an issue that Sheehan says isn’t covered enough. 

“This is particularly a problem where water levels fluctuate when the lagoon is iced over,” he says. “I’ve seen ice floes shear piping, aerators and curtain baffles and large chunks of ice suspended from the side of the lagoon that eventually dislodge and tear lagoon liners. I’ve also seen rocks get sandwiched between ice and liner and plastic liners and slice through the HPDE as easily as a knife.” 

In another sad case, Sheehan recalls a facility whose multi-ton concrete outlet structure was tipped by the ice cover once it had melted free from the sides of the lagoon. 

“The flow moved with the wind and as the water level dropped down it was able to contact the top of the monolith and torque it over, tearing the lagoon liner and creating a crisis as the water poured uncontrolled into the underdrain system,” he says. “This ended up being a $100,000-plus repair that could have been avoided.”



Discussion

Comments on this site are submitted by users and are not endorsed by nor do they reflect the views or opinions of COLE Publishing, Inc. Comments are moderated before being posted.