DoE: Contaminated wetlands pose little risk to humans

Though waste dumped by the National Roads Authority into the wetlands tested positive for carcinogens, it is very unlikely that humans are at risk from the contamination, according to the Department of Environment.

“The concentration [of carcinogens] in the soil at the wetlands only slightly exceeded the threshold and there is very unlikely to be a pathway to any human health receptors,” the DoE’s Environmental Management Unit stated.

The Department of Environment also stated that the wetlands that were used as a dumping site do not need to be cleared because the waste there will naturally decompose.

“In the DoE’s view, given that the discharges have not continued, the best thing to do with the wetlands is leave them alone and allow natural deposition and decomposition to occur. Wetlands are excellent filters and in some places, constructed wetlands have been used to treat wastewater,” the department stated. “Benzo(a)pyrene [the carcinogen] exceeded the thresholds in the sludge sample and the soil sample from the wetland, but not in the water collected at the wetlands, indicating it may already have settled out.”

The DoE further stated that the NRA’s waste is now being taken to an “elevated location” at the George Town landfill, “to facilitate the retention of contaminants in the mound while the water percolates through the mound so that contaminants do not end up in groundwater, and so further contamination of the wetland by the NRA vacuum truck contents will not occur.”

The NRA apparently did not violate any DoE rules: The department stated that the National Conservation Law “does not cover pollution in this context.”

“Protection of ground water comes under the Water Authority, Cayman and the Public Health Law addresses other aspects of pollution,” the DoE added.

The department stated that it acted as soon as it became aware of the situation.

The DoE’s statement came a day after the Water Authority released a report detailing the NRA’s practice of dumping wastewater and sludge from roadside storm drains into the island’s wetlands since at least 2011. The NRA began doing this after the Water Authority and the Department of Environmental Health stopped accepting the waste at their facilities.

According to the report, tests found the wetlands and well samples to contain the carcinogen Benzo(a)pyrene at levels higher than Florida soil remediation standards. Benzo(a)pyrene has been found in soot and is linked to “chimney sweeps’ carcinoma,” or cancer of the scrotum, according to the U.K.-based Royal Society of Chemistry.

Infrastructure Minister Joey Hew, who is responsible for the NRA, spoke on the results of the report on Thursday. He said his ministry welcomes the report, but that the NRA has already “put protocols in place” since the issue came to the forefront in June – after a Cayman 27 reporter found an NRA crew dumping in the wetlands.

“Unfortunately, the good people at the National Roads Authority were only doing their job to help alleviate flooding and damage to people’s homes in low-lying areas when vacuuming these wells,” Mr. Hew said. “I’d like to thank all the staff involved at the DEH and NRA and the Water Authority for helping us put together proper protocols in dealing with this drainage water.”

Mr. Hew also focused on the Water Authority report’s findings that the carcinogens in the waste likely came from road pollution that drains into the roadside wells.

“We have to start considering these illegal garages and the protocols by which people dispose of oil and carbons when working on cars. And also, as identified in our National Energy Policy, to work towards reducing our carbon footprint in the country, and embracing and encouraging more environmentally friendly vehicles and equipment around the island,” he said.