On January 26, 2006, the U.S. EPA adopted a reference dose (RfD) for perchlorate of 0.0007 mg/kg-day. This RfD equates to a Drinking Water Equivalent Level (DWEL) of 24.5 micrograms per liter (or 24.5 ppb).  Most states that regulate perchlorate in drinking water require reduction to below 1 to 18 ppb.  Current single-use and brine regenerable ion exchange processes for drinking water are expensive ($200 to >$500 per acre-foot). A perchlorate-selective, regenerable ion exchange process that minimizes or eliminates spent regenerating solutions would significantly reduce treatment cost.

Objectives:

·         Demonstrate performance of the weak base anion (WBA) resin technology for drinking water treatment in the State of California

·         Coordinate the demonstration with the California Department of Health Services (DHS)

·         Acquire data necessary to apply for a Domestic Water Supply Permit (DWSP)

·         Demonstrate “zero-discharge,” scavenger resin approach for treatment of spent regenerating solutions

Results and Benefits

A successful demonstration was conducted at Fontana, California, well site F-17.  The perchlorate concentration in the treated water was reduced to below the method report limit (<0.19 ppb) using IC/MS/MS.  Several resin regenerations were accomplished.  The spent regenerating solution produced was less than 0.03% of the treated water.  The spent regenerating solution was successfully treated using the zero-discharge scavenger resin approach to remove perchlorate to below method reports limits.  The scavenger approach cost less than $5 per acre-foot to implement based on conditions at the Fontana demonstration site.  Total treatment cost is projected to be less than $100 per acre-foot.  The WBA resin process can be used to simultaneously remove both perchlorate and nitrate anions.