Restoring and Managing Eutrophic Lakes & Reservoirs

Location of diffusers in Waterloo Lake

Article on the aeration of an eutrophic lake, lac Waterloo, 2004All lakes naturally age and this evolution takes place over a relatively long period of time. This phenomenon of eutrophication is the process of gradual enrichment of a lake with nutrients. This enrichment increases the presence of algae and aquatic plants. As a result, the body of water is transformed; observable changes include:

  • a greater accumulation of sediment and organic matter
  • a reduction of the level of dissolved oxygen in the water
  • and the replacement of organisms with species better suited to the new conditions.

This phenomenon of eutrophication can be accelerated by human activities. Premature aging is one of the main problems affecting resort lakes and lakes located in agricultural and urbanized areas.

For example, the articles below tell the story of Lac Waterloo, a municipal lake in Quebec. Our goal for this aeration project was to encourage the restoration of the natural processes that allow water quality improvement in Lac Waterloo with minimal human intervention. Aeration is the key ingredient that slows down eutrophication:Mise à niveau du système d'aération

Lac Waterloo, a Decade Later

In the summer of 2014 our crew returned to Lac Waterloo to upgrade the existing aeration system, the one we had installed a decade earlier in 2004. In the ten years since we had done the installation on the frozen lake, the Town of Waterloo had several changes in administration, council etc. resulting in interruptions in the annual maintenance schedule over the past decade. As such there were times when the aeration systems were not running to full capacity in Lac Waterloo. We cannot stress enough how important regular maintenance of an aeration system is to its performance, the operating budget and of course the water quality.Les diffuseurs OctoAir™ à l'oeuvre même en hiver!

A decade later, the administration was keen to re-evaluate the previous aeration system and make necessary changes for optimal aeration performance. In 2014 we worked for several days upgrading the existing system. This meant installing new compressors, repairing or doing regular maintenance on others. We cleaned the Bubble Tubing® diffusers using BioPurge (for the inner tube), manually scrubbed the exterior of the tube and re-positioned it as required. We also installed three OctoAir-10™ industrial grade diffusers in place of the Vertex discs diffusers that were no longer functioning properly. Upon inspection of the Bubble Tubing lines and the Torpedo airline feeder hose, we were very pleased to see both products were fully functional after a decade in the field (each has a 5 year warranty). We replaced a plug on one aeration line, reminding us why regular maintenance is critical to an aeration system performance.Le lac Waterloo au Québec

Related article