In August 2004, AdEdge Water Technologies was awarded a contract by the Black Canyon City Water Improvement District (BCCWID) in Black Canyon City, AZ, to provide a turnkey project for permitting, supplying equipment, installation, startup and commissioning of three new water treatment systems. The goal was to bring the district into compliance with a new maximum contaminant level (MCL) for arsenic.
The BCCWID, serving approximately 2,500 people, uses three main water supply sources that each deliver approximately 200 to 300 gallons per minute (gpm). Water treatment systems were provided at each wellhead to reduce naturally occurring arsenic ranging from 13 to 23 parts per billion (ppb). The district's board researched over 29 companies involved with arsenic treatment technology and chose AdEdge Technologies to complete this project based on lowest capital and operating costs, simplicity of operation and experience in Arizona with several other successful installations.
As part of the proposal process, AdEdge obtained certain site-specific design and water quality data to form the basis of the system. The design report and permit application were submitted to the Arizona Department of Environmental Quality (ADEQ), with construction permit approvals granted in less than four weeks. The rapid turnaround by the ADEQ was attributed to the technology receiving prior approvals in the state with a similar installation in Rimrock under the U.S. EPA’s Arsenic Demonstration Program.
Fabrication of the modular APU-300 systems commenced with site preparation tasks that included underground piping tie-ins, concrete pads and shade structures. Equipment was then delivered and installed. These systems were the largest to date of AdEdge’s installations in Arizona for public drinking water systems utilizing the granular ferric oxide (GFO) technology. Three separate APU-300 treatment systems (up to 300 gpm) were installed and deployed.
The small-footprint system features a twin vessel parallel flow configuration with automatic controls, PLC and a 100% backwash recycle system with zero discharge or loss of water. No pretreatment is necessary. Chlorine (sodium hypochlorite) is currently injected prior to the adsorption system for disinfection purposes. The AdEdge adsorption system requires no chemicals or regeneration, and does not generate liquid or hazardous waste. Media, when exhausted, will be discarded as a non-hazardous solid waste in a solid waste landfill.
Minimal operation, maintenance or operator attention is required for this simple automated system. Instrumentation is provided on a control panel to measure critical operating parameters. Total gallon throughput and flow rate for each vessel is measured continuously with a dedicated flow totalizing meter.
Installation and startup was completed in May/June of 2005 with ADEQ permit documents submitted. The permit was approved and all three systems placed into full service in October 2005. As of December 2007, treated effluent of the systems still indicated arsenic was being removed to below 10 ppb, exceeding predicted performance.
Case Study Fast Facts
Client: Black Canyon City Water Improvement District
Location: Black Canyon City, AZ
Date: June 2005
Contaminant treated: Arsenic
Flow rate: 120 gpm