The biggest health threat from the George Town landfill, according to engineers from Dart Realty, are fumes from fires at the site. The gases from the dump, the engineers say, are of no safety concern.
The engineers, who recently briefed parents at Cayman International School, also reported that their studies found higher than expected hydrogen sulfide levels coming from the nearby wastewater treatment plant. The levels were too low to pose any health threat but exceed odor control standards allowed in many other jurisdictions, they said.
The school, which is a Dart tenant, was closed to children as a safety precaution following recent fires at the landfill, which sent plumes of potentially toxic thick black smoke billowing across Grand Cayman.
Jeremy Moore, director of the Cayman International School, said the meeting last month was called because parents were keen to learn more about the landfill and its potential impact on the school and environment.
Mr. Moore said, “I believe the meeting was successful in providing important data and valuable information to parents. The studies conclude that the existence of the landfill itself is not an imminent safety concern to children and other persons on the school campus.
“Significant concerns with the management of the landfill site were discussed. Mismanagement of the site increases the potential for landfill fires to occur, and these fires are of monumental concern to the health and safety of everyone in Cayman.”
Martin Edelenbos, engineering coordinator for Waste Management at Dart Realty, briefed parents on some of the background issues at the dump.
He said large areas of uncovered garbage, including animal carcasses, the potential contamination of groundwater and large stockpiles of discarded tires, caused environmental and odor concerns.
But he said methane gases coming from the dump were not a significant health issue and air quality tests conducted by Dart had suggested the odor issue was also connected to the nearby sewage plant.
He said the odor from rotting garbage was an issue, but was not directly measurable by air quality tests.
The tests did reveal high levels of hydrogen sulfide, associated with the nearby wastewater treatment facility.
Many countries regulate the allowable amount of hydrogen sulfide in an effort to control the nuisance effect. In California, for example, the guideline is 30 parts per billion, averaged over an hour. The readings at Cayman International School showed levels of nearly five times that on some occasions.
The study did not uncover any potential health concerns for the school, but it did find some higher than expected hydrogen sulfide (H2S) levels related to operations at the wastewater treatment plant.
“The Dart study concluded that operations at the wastewater treatment plant, while not presenting a health risk, are resulting in ambient air concentrations of H2S in the community that exceed the allowable standards in many jurisdictions,” said Mr. Edelenbos.
The Dart study did not consider the impact of gases from large fires at the dump which are believed to pose a much greater health threat.