Barbados Water Resources and Secondary Water Reuse. Can we do more?
By Christian Marshall on 20 Jul, 2015
Barbados is blessed with a geological structure that is a near perfect water filter, providing subterranean streams of clean clear water that has been tapped and distributed across the island to meet our potable water requirements with little need for treatment since the early 1900’s. The relatively recent past history of development in the island (20+ years) has put this natural water supply under stress primarily through the increase in the shear number of users together with the related potential ground water contamination through physical development (read waste water wells), and the use of synthetic fertilizers in agriculture. Potential contamination aside Barbados is currently considered a water scarce country, as it does not meet the UN Commission on Water’s annual water supply benchmark of 1,000 cuM per person, or in fact the ‘absolute scarcity’ threshold of 500 cuM per person. The available annual water supply for Barbados is currently marginally over 300 cuM per person. This is just slightly ahead of the desert nations of the Middle East. (If only we had the oil.)
The deterioration of the water resources in quantity and quality has not gone unnoticed. The government of Barbados through its various Ministries has implemented several measures to combat the decline. These include legislation requiring homeowners and business to provide secondary water storage tanks to collect rain water, the installation of tertiary level sewage treatment plants required as a condition of approval from the Environmental Protection Department, the implementation of water supply metering together with a rate structure to curb consumer use, the establishment of a desalination plant to increase water sources, the ongoing mains replacement program to reduce water losses, and recent exploration for previously untapped subterranean water reservoirs.
These are all positive steps, however, the implementation of the secondary water storage tank regulations and the waste water treatment plant requirements need to be revisited in order to maximize the benefits with respect to water availability and economy. Current regulations require that rain water collected from roofs only be used for secondary uses such as irrigation and tertiary treated water from treatment plants be put into the ground. Our Caribbean neighbors are not as lucky as Barbados in that much of their water is derived from surface water runoff and localized rainwater collection. In Barbados we have been spoiled with an apparent abundant supply of good potable water. I spent my early life on a large oil camp in Trinidad where we had several large lakes primarily for use in the cooling towers in the adjacent oil refinery but also piped to all the residential properties, club house and sporting facilities and schools. I grew up knowing that only water from taps within a building was drinkable and you ‘DO NOT DRINK THE TAP WATER IN THE YARD’. The ‘inside’ potable water was supplied to the homes and other facilities from a water purification plant that drew source water from one of the lakes. The dual water distribution system worked well and I expect was efficient and economical. The lake water was largely drawn from a neighboring river (of questionable quality) down stream of many other population areas and also collected rainwater runoff from all the buildings, roads, plus general storm water runoff. The lakes provided a wonderful play ground where we would swim, fish, and hunt alligators. Many years later as a young man recently qualified I visited my boy hood home and all my old haunts. It was only then that I realized that the concrete structures that we would play on and jump off of into the lakes were septic tanks that discharges directly to the lakes.
My point is that secondary water can be utilized in Barbados to greater ends than currently permitted. The current regulations in a nutshell prohibit any use of treated effluent where it may come in contact with an individual. ie. Only drip irrigation or discharged down a well. This is not an economical equation when the cost of the treatment plant is significant. Secondary use water must be used in dual plumbing systems providing general irrigation, external water requirements, and toilet and urinal flushing. Only then will we be in a position to justify the expense of tertiary level waste water treatment and rainwater storage tanks.