It's every municipality's worst nightmare: a wildfire erupts on the boundary of your community, and every available resource must be deployed to fight it.

This was the reality for the residents of South Lake Tahoe on June 24, 2007, when the Angora Fire erupted into existence. The fire destroyed 254 residences and 75 commercial structures and burned 3,100 acres before being brought under control. Property damage from the fire was estimated to be in excess of $150 million dollars, excluding firefighting costs, which approached nearly $11 million dollars.

Ideally, water operators in fire-prone areas would like to keep their storage tanks at maximum capacity throughout the fire season.  But keeping water tanks full, especially during summertime months, means an increase in thermal stratification, residual loss, and the potential for water quality degradation.  

So water operators face a tense compromise between maximizing storage volume while avoiding water quality problems, especially with those tanks that are farthest from the treatment plant (often the tanks nearest to a fire incident).

With the installation of active mixers, this difficult compromise is no longer necessary. Water operators can keep even low turn-over tanks full all year long without worrying about water quality problems. Active mixing has been proven in multiple communities to improve the residual in water storage tanks by thoroughly circulating the residual to all parts of the tank. [See our case study from Spanaway, Washington.]This prevents biofilms growth, which cause further residual loss.

If you are using deep cycling to manage the water quality in any of your tanks, you are probably not getting the results you want. And, at least some of the time, your water level is lower than you'd like in the event of an emergency.

Instead of deep cycling and running the risk of encountering an emergency at the worst possible time, consider installing active mixers to keep your water quality AND your water levels as high as you want them to be.

How do you balance water quality with fire storage?  We welcome your comments and questions.

Sincerely,

Peter S. Fiske, Ph.D.

CEO, PAX Water Technologies