Arsenic Removal

The existing 69 operational, 13 blendable, 27 reserve, and 4 unconnected wells in the Hueco Bolson have a total capacity of 176 MGD. The operational and blendable wells provide 144 MGD.  Annually, these wells pumped a total of 50,438 acre-feet of water from the Hueco Bolson, supplying 41% of El Paso's total water demand. Of these wells, 14 units were identified as noncompliant with EPA’s new maximum arsenic concentration limit of 10 ug/L.

Preliminary studies conclude that an iron-based adsorption media was the preferred treatment approach. Pressure adsorption vessels were designed for treatment at each well site, with the additional requirement that vessels be sized to allow for other media if it becomes more cost effective than iron-based media. Some features of the modular treatment approach included self-cleaning mechanical filters, incidental radon aeration, spent media storage at the site and final pH adjustment before water enters the system.

Bath Engineering Corporation was a primary subconsultant to Brown and Caldwell for the design of this significant arsenic removal project.  Bath's scope of responsibility was for electrical, control, instrumentation and SCADA system design.