Floating Covers : evaporation and algae control for 20+ years

When properly designed reservoir, a floating cover systems prevent fluid loss due to evaporation, eliminate algae growth, reduce chemical demand and improve water quality by preventing contamination from bird droppings, airborne particulates, dead animals pollen and other pollutants.  Floating covers are extremely efficient at eliminating algae blooms because they block off sunlight.  They also reduce the production of trialomethane (THM) type compounds such as chloroform from forming that result from the combining of organic substances with chlorine due to reductions in chlorine demand.  In anaerobic digester systems, floating covers are increasingly being used to capture organic gases and to reduce biological oxygen demand (BOD).


Floating cover made of cheap material
Floating cover made of cheap material.

Floating cover systems in general were first introduced over 40 years ago.  Originally, most of them a solid fabric laying on top of the water. Some have provided a service life beyond 20 years, although many fail because of the drawback of this type of design. When first introduced, materials and designs were not developed and in some cases had limited success. Today, with advancements in design and materials, floating covers offer a low cost quality solution of choice where water quality standards require potable water reservoirs be covered. However, a new type of modular floating covers are replacing them. Advanced Water Treatment Technologies is a pioneer of those type of covers and now offers a wide range of long lasting options.

Floating cover applications range from dam cover for tailing ponds, to anaerobic digestion covers for wastewater systems, and potable water reservoir covers for municipal drinking water applications.  One application still requires the use of solid floating covers. In farming applications, they have been successfully used with enzymes to capture methane gas that is used to fuel electricity producing generators that can satisfy 150% of a typical swine farm’s electrical power requirements.  This alternative generates renewable “green energy” from an otherwise polluting system that provides zero return on investment.  In agricultural and other water management applications, floating covers are increasing  being used for evaporation control and odor control.

Evaporation control still remains the main use of floating covers, with efficiency reaching 98% depending on the cover. Modular floating covers have been growing in popularity due to their ease of install, zero maintenance and sometime more affordable price.