Water reuse and conservation in the United States Virgin Islands

Abstract

An assessment of the current water conservation and reuse practices in the United States Virgin Islands was undertaken by administering surveys to Territory Permit Discharge Elimination System permit holders and performing interviews. Currently, many resorts and condominiums in the US Virgin Islands (USVI) reclaim wastewater in response to water scarcity for such things as irrigation and toilet flushing, but few practice water conservation. Unfortunately, the municipal wastewater treatment plants do not practice any form of reuse. Because of the need for reuse and conservation planning in the community, eight reuse alternatives were developed for the two large municipal wastewater treatment plants on St. Thomas and St. Croix. Those reuse alternatives include: (1) residential irrigation on St. Thomas, (2) habitat restoration utilizing wetlands on St. Thomas, (3) community-wide conservation and habitat restoration on St. Thomas, (4) airport irrigation on St. Croix, (5) commercial irrigation and industrial process/cooling water on St. Croix, (6) agricultural irrigation on St. Croix, (7) habitat restoration utilizing wetlands on St. Croix, and (8) community-wide conservation and habitat restoration on St. Croix. Out of these eight alternatives, habitat restoration on both St. Thomas and St. Croix, community-wide conservation and habitat restoration on both St. Thomas and St. Croix, and agricultural irrigation on St. Croix are the most economical based on the normalized cost per gallon of reclaimed and conserved water. However, agricultural irrigation on St. Croix and community-wide conservation and habitat restoration on both St. Thomas and St. Croix provide the most benefits to the community. Agricultural irrigation provides farmers a low-cost option to meet water demand and production requirements. Community-wide conservation and habitat restoration alternatives provide an educational environment and promote conservation practices thus reducing water consumption, water cost, and wastewater production. From the assessment it is apparent that promoting conservation and reclaiming wastewater effluent results in a reduction of effluent discharged to the ocean, conservation of fresh-water sources, reduction of energy and pollution due to lower production needed by USVI Water and Power Authority (WAPA), and avoidance or delay in USVI WAPA expansion to meet non-potable water needs. Before undertaking design of a reuse project incorporation of public information and participation, public health impact identification, and local and federal government participation is crucial to project success.