The Autauga County Water Authority in Prattville, Ala., has been providing water to Autauga County residents and businesses for decades. Not long ago, the Water Authority was facing a significant treatment problem with its water supply. Levels of iron and manganese had risen to unacceptable levels and the Water Authority was looking for solutions to reduce the contaminants to acceptable levels.
Working through its consulting engineer, Chambliss Engineering LLC of Prattville, the Water Authority called upon Layne Christensen for options.
Layne Christensen Co. provides products and services for the water, mineral, construction and energy markets. The company’s water services include single source, full service capabilities encompassing expertise in geosciences, water well drilling, pumps, water and wastewater transmission infrastructure and water and wastewater treatment . The company offers advanced treatment technologies for the removal of arsenic, iron, manganese, radionuclides, perchlorate, nitrate and volatile organic contaminants. With more than 50 strategically located offices throughout the U.S., Layne is uniquely positioned to offer comprehensive, integrated solutions and services for the extraction and purification of groundwater and surface water for municipalities, investor owned utilities, industrial, power and agriculture and oil and gas sectors.
Layne’s water treatment engineers reviewed the conditions and tested for water samples at the treatment plant. They found that Autauga County Water Authority water was high in contaminants with iron at 1.25 parts-per-million (ppm) and manganese at 0.10 ppm. Given the longstanding success of Layne’s high-rate granular filter media, Layne engineers quickly recommended installation of a 400-gal-per-minute (gpm) LayneOx filtering system .
LayneOx operates as both a classical filter working with an oxidant and as a catalytic media due to its ability to accelerate the reaction between the oxidizing agent and the iron and manganese present. Because it contains naturally high manganese dioxide content, LayneOx aims to provide a higher adsorption capacity and faster reaction times than other media.
The LayneOx system would benefit the Water Authority in several ways. Historically, filtration methods for iron and manganese has been designed around 3-gpm/sq-ft flow rates, and require the addition of both potassium permanganate and chlorine to oxidize and remove the contaminants. Layne proposed a more efficient design that accommodates a 6-to-12-gpm/sq-ft loading rate and requires only one oxidant, sodium hypochlorite. Not only was Layne’s design less expensive to construct, the improved performance also provides financial benefits in the form of a smaller building, reduced chemical use and lower operating costs.
While other systems were considered, the LayneOx system was selected for its efficient iron removal, ease of use and low maintenance requirements. The Water Authority appreciated that their crews were not burdened with constant operations and maintenance.
The installation process went as planned and LayneOx was soon treating Autauga water. The finished water results ? Iron had been reduced from 1.25 ppm to 0 ppm , and manganese had been reduced from 0.10 ppm to 0 ppm as well.
In this water treatment case, zero became the magic number.
Contributing authors include Brad Fine, marketing specialist; Doyle Goodman, general manager, Layne Central; and Bill Van Pelt, account manager, Layne Central.