Public water system in Raleigh, N.C., uses oxidation/filtration media to comply with EPA regulations
In July 2009, AdEdge Water Technologies  was contacted by Aqua North Carolina to provide an iron and manganese removal system for the Sunset Forest public water system located just outside Raleigh, N.C.
The raw water had an average iron level of 0.49 mg/L and a manganese level of 0.39 mg/L, well above the U.S. Environmental Protection Agency's (EPA) secondary maximum contaminant levels (MCLs) of 0.3 mg/L and 0.05 mg/L respectively.
Finding a Solution
AdEdge designed and manufactured a skid-mounted AD26 oxidation and filtration package unit, which is sized for a maximum design flow of 50 gal per minute.
The model AD26-3060CS-2-AVH utilizes AdEdge AD26 media in a two-vessel carbon steel configuration in parallel. The system is equipped with automated control valves and harness, the AdEdge INGenius central control panel with programmable logic controller and a color user interface screen.
System features also include differential pressure switches, control panel and local gauges, flow sensors and totalizers, and a central hydraulic panel with sample ports for a complete functioning packaged unit.
Each 30-in.-diameter treatment vessel contains 13 cu ft of the oxidation/filtration media, which is a NSF 61-certified manganese dioxide media. Prior to the treatment system, a chemical feed module injects chlorine for optimal removal of the iron and manganese.
In addition to the iron and manganese treatment, the system features the AdEdge H2Zero recycle backwash system. This system reclaims 100% of the backwash wastewater and removes the captured iron and manganese as a semi-solid sludge that can be disposed of in a non-hazardous landfill.
Backwashing of the treatment system occurs two or three times a week depending on the incoming levels of iron and manganese and water usage.
The system began operations in March 2010. Since then, iron and manganese levels are below the EPA secondary MCLs of 0.3 mg/L for iron and 0.05 mg/L for manganese.