Maintaining Water Supplies to a Remote Island Population When Source Water Becomes Contaminated.

摘要

On December 8, 2008, the island of Roi-Namur had high wave activity (onset of dry season). Nearly all of its lenswells were contaminated with salt water. A drinkable chloride concentration is 250 mg/L; ocean water chloride concentration is 35,000 mg/L. The only well not contaminated had a history of Volatile Organic Compound (VOC) contamination. There are roughly 12 days of raw water in storage under normal operation, and roughly 30 days of treated water in storage under normal operation. The Army's goal was to utilize the contaminated lenswell to supplement the island's drinking water. Water treatment consisting of Granular Activated Carbon (GAC) filters was initiated to extend the water supply. Other water options: barge water from Kwajalein Island, dig new wells, or install new treatment for brackish water (reverse osmosis purification units, or ROWPUs). Temporary ROWPUs were installed on Roi- Namur on February 6, 2009. ROWPU is costly. Rainfall is needed and the estimated recovery time is 2 years (2011). A permanent reverse osmosis system was installed in January 2010. There was very good lenswell water quality this year.