Around two-thirds of a million tyres were shredded in an 16-month recycling project that wrapped up at George Town landfill last month.
The resulting product, tyre derived aggregate, is being used as fill at construction sites, but is it safe?
The Department of Environment told Cayman 27 TDA is widely used as a building material, and says while the shredded tyres do contain potentially toxic substances, the current thinking is they do not present a major environmental hazard.
The DOE said the biggest area for potential problems with TDA are in its interactions with the water table.
Water Authority Cayman Corporate Communications Officer Hannah Reid told Cayman 27 the Water Authority has implemented standards for TDA use.
“Those standards include keeping the tire aggregate free of contaminants, making sure that none of the tires have been exposed to fire, and there are a few other criteria that the Water Authority has listed so that the tires are able to be used as aggregate safely,” said Ms. Reid.
She told Cayman 27 the standards are based on those of international standards organisation ASDM.
- The TDA (tyre derived aggregate) shall be free of all contaminants including but not limited to oil, grease, gasoline and diesel fuel that could leach into the groundwater or create a fire hazard.
- In no case shall the TDA contain the remains of tyres that may have been subjected to a fire because the heat of a fire may liberate liquid petroleum products from the tyre that could create a fire hazard when the TDA are placed in a fill.
- The TDA should be free from fragments of wood, wood chips, and other fibrous organic matter.
- The TDA layer shall be less than 1 metre (3 feet) thick.
- The TDA shall not be placed below the water table.
- The Authority also reserved its right to withdraw its endorsement of the project in the event that it is determined that the use of TDA results in the contamination of groundwater, which the Authority is mandated to protect for the benefit of present and future generations.
- The developer is also required to contact the Authority prior to commencing the placement of the TDA so that the Authority can conduct a site visit.