2nd International Conference on Rain Water Cistern Systems
St Thomas, Virgin Islands - June, 1984

Section E: Quality Considerations

Paper E.4

Rainwater Cistern Systems: The Park Experience

James Riddle
Virgin Islands National Park

Ronald R. Speedy
National Park Service

Abstract

Created by an Act of Congress in 1956, the Virgin Islands National Park encompasses some 7,150 acres on two islands - about 7,000 acres on St. John, and about 150 acres on St. Thomas. Rainwater cisterns are the primary source of water for the park's 25 water systems. Of these, 22 serve individual residences for park employees and their families. The remaining three serve both employees and visitors in facilities such as visitor centers.

At first, most of the park's facilities consisted of buildings that existed when the land was either purchased by the National Park Service or donated to the Service. The roofs of these buildings were constructed of various materials, including asbestos-cement panels, metal panels, concrete, and concrete with various coverings. Typically, metal roof gutters led to a: concrete cistern under the building. The capacity of the cisterns ranged from 5,000 gallons to 20,000 gallons. Normally, water was supplied to the building by a small centrifugal pump and a hydropneumatic tank. Some buildings had a hypochlorinator wired to run when the pressure pump ran. The hypochlorinator used full-strength household bleach (5 1/4% available chlorine) as the solution fed to the system. The pressure tanks were used for chlorine contact. Normally, no filtration of any type was provided.

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