Nevada Conservation Camp Eliminates Arsenic
At the Humboldt Conservation Camp, a containerized treatment system reduced arsenic in the water supply to non-detectable levels
In June 2008, AdEdge Water Technologies LLC was contacted by Brown and Caldwell of Carson City, Nev., to assist in the design and selection of an arsenic treatment system for the Humboldt Conservation Camp near Winnemucca, Nev.
Arsenic concentrations at the site fluctuated between 17 ppb and 22 pbb, well above the U.S. Environmental Protection Agency (EPA) maximum contaminant level (MCL) of 10 ppb. The existing water system consisted of a well feeding into a centralized distribution system with a maximum capacity of 260 gpm. AdEdge assisted Brown and Caldwell in providing drawings and system specific information in preparation for the public bid by the State of Nevada, which occurred in April 2010 and was awarded to AdEdge the subsequent month. AdEdge contracted Bison Construction to install and commission a containerized arsenic water treatment system for the Humboldt Conservation Camp.
The AdEdge treatment system features an adsorption package unit enclosed in a WaterPod modular containerized building sized for a maximum design flow of 260 gal per minute. The model APU33-4860CS-3-MVH utilizes AdEdge’s granular ferric oxide (GFO) media in a three vessel carbon steel configuration in parallel. The arsenic removal system is housed inside a 20 ft cargo container equipped with HVAC, pedestrian doors, ventilation vents, windows and lighting. The WaterPod system sits on a concrete slab base and is pre-designed and pre-piped, ready for “plug and play” when it arrives at the site.
A continuous feed of sodium hypochlorite is fed prior to the treatment system to optimize the removal of arsenic. The influent water flows through three bag filters prior to the arsenic removal system to remove any particulates that may disrupt the functioning of the arsenic treatment vessels. Each 48-inch diameter treatment vessel contains approximately 41 cu ft of AdEdge GFO adsorption media. AdEdge GFO is a NSF 61 certified granular ferric oxide media used for the removal of arsenic. The treated water is stored in a 120,000-gal storage tank prior to distribution. Backwashing of the arsenic treatment vessels is performed every 45 to 60 days to prevent hydraulic channeling and to ensure good flow characteristics. Waste from the backwash event is stored in a holding tank to await disposal. 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.
The system was started up and commenced in October 2010. Since the system began operation, arsenic levels have lowered from 17 ppb to non-detectable levels.
Richard J. Cavagnaro is marketing coordinator for AdEdge Water Technologies LLC. Cavagnaro can be reached at [email protected] or 678.835.0052.