A regular Source feature, Undercurrents explores issues, ideas and events as they develop beneath the surface in the Virgin Islands community.
Suppose there were a concrete additive that helped to purify water passing over it.
Put it in roofing material on your home and/or in your cistern walls, and you just might improve the quality of the water you drink – substantially.
It’s not a dream; it’s a research project funded through the V.I. Water Resources Research Institute.
The institute, established at the University of the Virgin Islands, has been sponsoring water research in the territory since 1974, said its director, Henry Smith, who is also director of V.I. Experimental Program to Stimulate Competitive Research.
The Water Resources Research Institute also partners with other institutions on some projects: for instance, the study of the roofing material resulted in a research paper titled “Inactivation of Fecal Coniforms During Rainwater Harvesting by Engineered Pervious Layer,” which was produced by the Engineering Department at the University of Puerto Rico.
Like the other 53 institutes at land grant colleges and universities in the states and territories, the V.I. WRRI is funded in part by the U.S. Geological Survey. It also is supported through UVI and through contractual projects.
The USGS grants approximately $80,000 annually to the territory specifically for local research projects. UVI researchers were invited to submit proposals for the 2015-16 cycle by Nov. 14. Smith said those will be evaluated in-house and the institute will make the first cut, then forward its selections to USGS, which will make the final determination.
One of the criteria for selection is the proposal’s relevance to the needs of the community. Smith said in the past that much of the local research focused on cistern contamination and on desalination efforts, as those items were especially pertinent in the Virgin Islands.
More recently, he said, there’s been more research on microclimates and on water distribution.
Obviously, in an area where water is scarce, water resource studies are more than an academic exercise.
There is really no “average” amount of water usage. It varies widely depending on geographic and economic circumstances.
However, as a rule of thumb, the USGS says in the U.S. the average person uses between 80 and 100 gallons of water per day. That includes drinking, bathing, dish washing, cleaning and toilet flushing.
In the fresh water-deprived Virgin Islands – one of the few jurisdictions in or outside of the U.S. where buildings are required by law to maintain cisterns – people tend to be far more conservative in water consumption, Smith said. He did not have current figures but said that years ago the average usage was closer to 20 gallons per day than the 80 to 100 gallon national rate.
The V.I. Water and Power Authority does have some recent data that also reflect low usage.
Rupert Pelle, director of the water distribution system on St. Croix, said the average household customer on the WAPA system alone uses between 2,500 and 3,000 gallons per month. Using the higher figure, and calculating 30 days to the month and 3.5 persons per household, that works out to an average daily usage of 28.5 gallons per person.
It’s impossible to calculate usage by individuals who use WAPA water to supplement their cistern water or those who use only cistern water.
According to 2010 Census data, the majority of households – some 28,599 – relied solely on cisterns, while 16,478 had no cistern and were tapped into the public system. Another 9,783 used both sources. Interestingly, 944 said they used “other sources,” which would include private wells, and 78 were still using the old-fashioned standpipe.
While scarcity obviously encourages water conservation in those who rely on rainwater, Pelle suggested that cost is the incentive for those who buy it from WAPA. The current price is $27.18 per 1,000 gallons, which translates to about 2.5 cents per gallon.
The authority produces more than 1 billion gallons annually on St. Croix, and a little more than 789 million gallons in the St. Thomas-St. John district, Pelle said. St. Croix has 200 miles of pipeline and storage capacity for 22 million gallons. St. Thomas, where the hilly terrain makes distribution more difficult, has 70 miles of pipes and storage capacity for 37 million gallons.
Don’t look to the WRRI for work on actually increasing rainfall in the islands.
“We’ve never done that,” Smith said. When one area tries to maneuver nature to increase its water, it invariably reduces the water in another area. The institute’s focus instead is on managing available resources and collecting information. “We focus a lot on gathering data.”
Among the long list of projects sponsored by the institute are:
– A Computer Model for Simulation of a Water Condensation System;
– Design and Operation of the UVI Aquaponic System;
– Land Use, Runoff and Recharge on Selected Watersheds in the U.S. Virgin Islands;
– Point of Entry Cistern Water Purification Units Development;
– Measurement and Prediction of Sediment Production from Unpaved Roads, St. John;
– Water Quality if Public Distribution Systems of the Virgin Islands;
– and Water Usage and Papaya Growth in Double-Row Systems Established During the Dry Season.
For a full list, visit www.uvi.edu and go to the water resources research institute.
