For many water and wastewater treatment plants, the challenge of establishing adequate chlorine contact time (CT) is one of the largest. Sufficient contact time between the water and the chlorine is one of the most important methods of ensuring reliable and complete disinfection of the water product.

As contact time requirements become more stringent in many states, existing plants are faced with serious challenges. Many established reservoirs are simply too small to allow for sufficient CT as-is.

The solution in many instances is to add baffles to the reservoir. Baffling forces the water to follow a serpentine path from inlet to outlet, extending the distance traveled by the water (and consequently, the chlorine contact time before release).

Baffles are offered in many materials of manufacture, including concrete, wood, and synthetic materials. In most instances, the most economical option that allows for the most flexibility down the road is to install baffles made of potable-grade reinforced geomembranes. Concrete can be cheap, but it also doesn't allow for any modifications to be done down the road...and modifications to existing standards are why many plants have to install baffles in the first place. Concrete also requires significant maintenance over time. Wood simply doesn't do the job in the same way as better materials like geomembranes.

In most cases, tank baffles offer the best options. When fabricated from materials like XR-5, they can be exposed to sunlight, harsh weather conditions, and high doses of chlorine without degradation or wear.

Due to their flexibility, tank baffles can be installed in a full spectrum of applications, including water towers, below-ground clearwells, above-ground storage reservoirs (GSR's), and standpipes.

When properly fabricated by a reliable manufacturer and installed with stainless steel angle, clearwell and wastewater tank baffles can provide an extremely effective means of extending contact time while remaining highly economical and allowing for changes and adaptation for years to come.

If you have questions about using baffles to extend chlorine contact time in your system, please use our contact form to describe your situation and we'll be happy to help.

last revised 10.19.2005