In November 2009, AdEdge Water Technologies LLC was contacted by Great West Engineering to provide an arsenic- and iron-removal system for the Gore Hill County Water Treatment Plant Wells No. 1 and No. 2 in Great Falls, Mont. The existing water system consisted of multiple wells feeding into a centralized distribution system with a maximum capacity of 150 gpm. The raw water for Plant No. 1 has an average arsenic level of 18 ppb and an iron level of 1.39 mg/L, which is well above the EPA limits of 10 ppb and 0.3 mg/L, respectively. Plant No. 2 has an average arsenic level of 21 ppb and an average iron level of 4.51 mg/L, also well above the EPA limits of 10 ppb and 0.3 mg/L.

The solution
Each AdEdge treatment system features a skid-mounted AD26 oxidation and filtration package unit sized for a maximum design flow of 150 gpm. Gore Hill Plant No. 1 features the model APU26-4260CS-2-AVH and uses AdEdge AD26 media in a two-vessel configuration. Gore Hill Plant No. 2 features the model APU26-4260CS-3-AVH and uses AdEdge AD26 media in a three-vessel configuration. Each system is equipped with automated control valves and harness, a 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. A continuous feed of sodium hypochlorite is fed before the treatment system to optimize the removal of arsenic and iron. Each 42-inch diameter treatment vessel contains 28 cubic feet of AdEdge AD26 oxidation/filtration media.  

In addition to the arsenic- and iron-treatment systems, AdEdge is providing a backwash-recycle system for each site. The backwash-recycle system reclaims 100 percent of the backwash wastewater and removes the captured arsenic and iron as a semisolid sludge that can be disposed of in a nonhazardous landfill. Backwashing of the treatment systems occurs two or three times a week depending on the incoming levels of iron and water usage. 

Results
Since the system began operation in April 2011, iron levels are at nondetectable levels and arsenic levels have lowered from 18 ppb and 21 ppb to nondetectable levels.

About AdEdge Technologies
AdEdge has extensive experience in the removal of arsenic, iron, manganese, fluoride and uranium from water, and to date has installed hundreds of water systems for public, municipal, and industrial clients throughout all of North America as well as some projects in some of the most challenging locations in the world including China and Indonesia. For more information, visit www.adedgetech.com.