Firm focuses energy on efficiency: opportunities found in inefficient wastewater treatment plants. (Engineering).

Through their retrofit work in five wastewater treatment plants in the Sudbury region, J. L. Richards and Associates Ltd. have saved the region $1 million in energy costs and in the process, helped the environment.

"Providing plants with more energy efficient operations has been the opportunity," says Saverio Parrotta, P. Eng. with J.L. Richards. "A lot of the plants are old and have old technology."

One of their major projects was the Walden Wastewater Treatment Plant. The facility's head works went through extensive upgrades to accommodate a change from manual equipment to mechanical equipment.

"We provided them with a more effective way of cleaning up grit and other solid material," says Parrotta.

The head works is the first place raw water encounters upon entering a plant.

A major change in technology is the transition of coarse air bubble diffuser systems to fine bubble tube membrane diffusers in plants.

"The coarse systems required a lot of air and were expensive," says Parrotta. "Changing to a fine system provides better efficiency for the air."

The systems are used in the aeration tank to keep solids suspended. Without the process, the solids would settle at the bottom of the tank and become septic.

By reducing air, plants were able to downsize equipment to supply that air and in turn save money.

Another area where technology is expanding the efficiency of plants is in controls called variable frequency drives (VFD).

"When you equip a blower with a VFD, you can reduce the rpm of motors in time when air is not required as much, like at night when people are sleeping," says John Cannard, P. Eng. with the firm. "It all translates into energy savings."

The completed retrofitting work and that which is currently under construction has put Sudbury on the map in a different way.

"Sudbury is known as a model in the world for this type of energy initiative," says Cannard. "It all ties into a focus the city has with Earth Care and being energy self-sufficient, reducing greenhouse gases and overall energy savings."

One of the biggest challenges in retrofitting a plant is implementing the changes while maintaining operations at the facility.

"It is more difficult than designing a new plant because you have to do it in a safe manner," says Cannard.

The firm also had to prove to the city that the money being spent on the upgrades would be recouped within seven years.

"We had to design a plan that was viable and prioritized the opportunities for improvements," says Parrotta.

The firm has upgraded the plants in Dowling, Walden, Levack, Valley East and Chelmsford. Currently they are finishing up the retrofitting work in the Azilda facility.

Cannard says the retrofits were a huge undertaking and he credits the city for making the decision to forge ahead with the upgrades.

Besides the energy savings to the region, the retrofits have a profound impact on the surrounding environment as well. The upgrades have improved the quality of the effluent that is discharged into local rivers and lakes.

"It is great because the effluent goes into our rivers and lakes that we drink from and swim in," says Parrotta. "It benefits the entire community and the environment"

The retrofits resulted in a win-win situation for the firm and the city.

"We have improved operations and saved money for the city, and it is gratifying for us doing this important work," says Parotta. "These facilities and services need to be looked after because it affects everyone."

J. L. Richards has received positive feed back from their clients about the upgrades.

"The supervisors were all receptive to the work and every time we are done we get excellent feedback," says Parrotta.

The firm has overseen the initial investigation of the plants, the design and construction of upgrades and the commissioning of the facilities.

The firm is also doing the complete design and consultation of wastewater treatment facilities in Kingston West and the City of Pembroke.