Students Find “New” Source of Sewage Pollution
The Tobago House of Assembly needs 100’s of millions of dollars to build a sewage system for southwest Tobago. That this area is prone to coastal sewage pollution has long been known. It has also been accepted that there are many existing package treatment plants, both residential and commercial, that are operating far below acceptable standards. Yachts have been identified as a source of pollution and small animal farms are known to contribute to the problem.
Now, secondary school students working with Environment TOBAGO have confirmed yet another source. Student participants in the Tobago Community Water Watch Network took water samples from storm drains and street gutters in the coastal villages of Buccoo, Plymouth and Charlotteville. Gross levels of sewage contamination were recorded at all three villages. Surface water flow surveys indicate that much of this contamination is coming from residential septic systems.
Signal Hill student takes sample from storm drain
Residential septic systems are not inspected in Tobago. The plans for residential septic systems are supposed to be approved by the Health Department, but without inspections, builders often install systems that just don’t work.
They don’t work for several reasons. They may be located too close to a water course or storm drain. They may be too small to handle the amount of effluent they receive. The soil in which the soak-away is placed may be too compact (like clay). Even if a system works for a while it can often fail in time. The sludge in septic tanks needs to be pumped out periodically or the system will stop working. In dense soil, leach fields can become clogged. Chemicals, such as bleach or diesel (which is sometimes used to kill mosquitoes), poured into a pit latrine will kill the bacteria necessary for treatment.
Untreated sewage from mal-functioning septic systems finds its way to a water course, storm drain or street gutter and flows quickly to the sea.
This year (1999) in Key West, Florida, USA, where the economy is based on tourism, an almost identical situation has forced the closing of all but one bathing beach for public health reasons. Although public officials had known of the problem for decades, they dragged their feet in regard to fixing it.
In Tobago we have three options:
(1) clean up the bathing beaches where sewage is posing a health hazard;
(2) post warning signs or close the contaminated beaches; or
(3) continue to allow unsuspecting bathers to be exposed to skin rashes, ear infections and gastrointestinal diseases.