Reservoir Controls for T&O

T&O compounds in lakes are usually stratified with depth.  Algae grow in the warmer water of the upper portions of the lake (epilimnion).  Fortunately in the metro-Phoenix region terminal reservoirs have hypolimnetic withdrawal; that is water is released from deep in the lake. Lower T&O concentrations occur deep in lakes, until after thermal destratification of the lakes in the fall of each year.  During thermal destratification the lake "turns over" and is completely mixed, resulting in fairly uniform T&O concentrations with depth.  This is a major source of T&O compounds to downstream WTPs.  Visit the Saguaro Lake Case Study for example data.

Treatment Options (see below for more details)

Apply biocide to reservoir water

Change depth of water withdrawal

Release water for a reservoir with lower T&O concentrations

Switch finished water production to WTP supplied by different source water

Reduce production of treated surface water and pump groundwater into pressurized distribution system