Castaic Lake Water Agency was faced with a dilemma: how to support the increasing water
needs of a growing population in the Santa Clarita Valley with three to five wells in the area shut
down due to the presence of perchlorate. Carollo Engineers was hired to design a treatment
program for the removal of perchlorate from Saugus Aquifer. Several unknowns challenged the
project including an uncertainty in a regulatory MCL for perchlorate, lack of brine line in the area,
and low chloride limits in LACSD sewer lines. One of the selected alternatives was throw-away
ion exchange. Selection criteria included cost, minimal formation of wastes and full-scale
demonstration of the processes. Bench-scale testing of the ion-exchange resins was conducted
over a period of 3 months. Single-use ion exchange resins performed well to remove perchlorate
below the detection level. The adsorption cycles of two of the resins lasted more than 70,000
bed volumes before perchlorate was detected in the effluent of the columns (approximately
200,000- 550,000 gal/cu-ft resin). No NDMA was formed as a result of post-chlorination with free
and combined chlorine, or as a result of prechlorination with free chlorine. The metals measured
in the spent results were well below the TTLC and STLC limits, despite the long run times. Ionexchange
is therefore a feasible technology for treatment perchlorate in the Santa Clarita Valley. Includes tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 5 |
| Published : | 11/15/2004 |
