The Water Authority has revealed the names of the worst performing sewage treatment plants on private property in Grand Cayman.
Georgian Court Villas in Ithmar Circle, off Fairbanks Road, exceeds the legal limit of total suspended solids, which are supposed to be broken down by the sewage treatment plant, by 240 times.
Residents of Georgian Court Villas say the area routinely stinks.
‘It always seems to smell bad here. I think it must be coming from there,’ said one resident, pointing to the metal covers over the treatment plant on the footpath immediately in front of the houses.
The estate’s sewage treatment plant is also more than 100 times over the legal limit of biochemical oxygen demand, known as BOD, which is the amount of oxygen needed by bacteria to break down large organic molecules into smaller molecules.
The legal limit for both biochemical oxygen demand and suspended solids in Cayman is 30 parts per million.
In its testing of 186 plants on the island between April last year and February this year, the Water Authority found that 100 of them – more than half – exceeded the legal limit.
Other properties in the Fairbanks area also had poorly performing sewerage systems, according to the findings. Stone Haven Apartments showed results of 1,416 parts per million of BOD, while L’Ambience showed had results of 1,254 BOD, exceeding the legal limit by 40 times, and a TSS result of 1,030, exceeding the limit by more than 30 times.
Grand Palms of the Caribbean, a complex of 14 luxury apartments located in South Sound, also showed BOD results far exceeding the legal limit, with 1,851 parts per million.
Government housing estate, Windsor Park, also exceeded the legal limit. Its biochemical oxygen demand was 859.5, while its total suspended solids results were 1,071.2.
A. L. Thompson at Countryside Shops was also above the legal limit, with 855 parts per million of BOD and 115 parts per million of TSS.
Other private complexes listed among the worst offenders on the island were Cayman Crossing in South Sound (745.5 BOD and 124 TSS) Walker’s South Apartments (510 BOD); Templeton Pines (699 BOD and 530 TSS); Windsor Lakes (449.5 BOD and 462.5 TSS).
A group of luxury developments, Coco, Sunset, Garden and Mystic Retreats in John Greer Boulevard in George Town showed a BOD of 496.5.
The Mirco Centre, Elizabethan Square and Caribbean Utility Company were also tested and originally found to exceed the legal limit, However, the Water Authority said the samples were ‘from a make of package plant that uses a process different from the others… this system was sampled at the wrong time. The results are therefore invalid and the system will be correctly re-sampled.’
The results of the worst 18 properties were revealed to the Caymanian Compass following a Freedom of Information request.
Mike Smith, a specialist in wastewater treatment at the Water Engineering and Development Centre at Loughborough University in the UK, in an earlier interview said waste water with high levels of biochemical oxygen demand could result in the depletion of the dissolved oxygen in water, which meant fish would have to compete with bacteria for oxygen in the water.
The authority insisted that improperly treated sewage is not finding its way into Cayman’s waters because it is ‘discharged via disposal wells that transmit the effluent laterally through the island’s formation in saline groundwater at a depth of 40 to 100 feet before reaching the near-shore waters.’
The Water Authority took the samples between 17 April, 2008, and 26 February, 2009. There are 524 private sewage treatment plants on Grand Cayman.