October 28, 2015

Dump strategy aims to cut waste by at least 85 percent

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dump horizon

Recommendations in the new solid waste management strategy, essentially what to do with the George Town landfill, focus on how government can prolong the dump’s useful life beyond summer 2021.

The report sets out a strategy that, if implemented in its entirety, could reduce up to 10,000 tons of waste a year, about 85 percent less than what goes into the landfill today.

The consultants say recycling, composting and incinerating trash may push the landfill capacity for another “limited number of years,” but the country will still need a new landfill in the next decade.

According to updated estimates from the new draft Solid Waste Management Strategy report from consultant Amex Foster Wheeler, about 40 percent of the waste in the landfill now could have been recycled. Of the estimated 62,000 tons Grand Cayman sent to the landfill last year, almost 10,000 tons is yard waste that could instead be composted.

The consultants estimate that in the next 50 years, waste sent to the landfill could increase up to more than 250,000 tons per year if nothing is done to cut back. Even the lowest estimates put the waste headed to the landfill at 100,000 tons annually 50 years from now. The report states, “Underlying waste growth linked to population growth if left unchecked would result in a considerable increase in tonnage of solid waste.”

Mt Trashmore InfographicThe strategy in the report ties in recycling and composting, and it turns the landfill into a power plant, burning the waste as it comes in to generate electricity.

Reducing what goes into the landfill, the report states, “can be as simple as passing things we no longer need on to other people to use, for example by giving items to friends or charity shops.”

The consultants write, “Waste can be prevented by both business and the general public by thinking about what we need and buy. For example, residents can reduce waste by using cotton shopping bags instead of plastic shopping bags and avoiding over-packaged products where possible.”

Composting

Almost 10,000 tons of yard waste went into the landfill during the 2013-2014 fiscal year, about 15 percent of all the waste that went into the dump during the year, according to the report. The consultants state, “This material has the potential to be composted using relatively simple technology and converted into useful compost/soil conditioner that [can] then be beneficially applied to land.”

The strategy calls for trials to test composting systems for yard waste with an eye to setting up simple composting plants on Grand Cayman and Cayman Brac. Composting food waste would take a more complicated system and the report notes that the low amount of waste from food doesn’t justify the expense.
Target 2017/18 for Grand Cayman, 2019/20 for Cayman Brac

Recycling

The proposed plan calls for increased recycling across the islands. The first step is to put recycling depots in high-visibility areas that are convenient for people, such as supermarket parking lots, with separate bins for different recyclables like paper, metal cans, glass and plastics. The report also calls on government to look into the possibilities for curbside recycling pickup for homes and businesses. The long-term strategy includes central recycling centers on all three islands and potentially more than one for Grand Cayman. The recycling facilities can sort through the different materials using magnets, separators and manual sorting.
Target 2016/17

Waste to Energy

The report looks at several options for breaking down the waste instead of sending it to the dump. The ultimate recommendation is to build a power plant to convert waste into energy.

The system would work like any other power generator, but trash is the fuel source.

The plant incinerates garbage and the resultant heat produces steam to drive a turbine, supplying power back to the grid. The consultants write that the amount of energy produced in the system varies depending on how much waste is burned and how much heat it puts off to fuel the turbines.

The facility would be designed to capture any air pollution, which would be turned into solids and then treated and sent to the landfill. Ash from the incinerator, the report explains, can be used as aggregate to pave roads or make cement blocks.

The consultants write: “The footprint of a WtE facility can be relatively small when compared to other residual waste treatment facilities … The architectural design of WtE facilities is very varied and can range from iconic buildings, industrial buildings or designs that blend with the local landscape and environment.”
Target 2019/20

The Sister Islands

The strategy calls for government to close the dumps on Cayman Brac and Little Cayman. Instead, the report suggests putting transfer stations on the Sister Islands to ship the waste and recyclables to Grand Cayman for treatment or export. The report also recommends recycling centers on both the Sister Islands and a composting facility for yard waste on the Brac.
Target 2019/20

What to do with the dump

The landfill will be the last option for solid waste, the strategy plan states. Even with recycling every possible thing and following each recommendation, the consultants say the island still needs a landfill. To extend the life of the existing landfill, the report states, government will study mining the landfill for anything that can be taken out and recycled. Nevertheless, the consultants write that the Cayman Islands will need a new dump site sometime down the road.

Not all waste, the strategy lays out, will be suitable for recovery or economically recycled. The waste-to-energy plant will have some outputs that cannot be reused, and the landfill will have to be used whenever the other facilities close for maintenance. When the current site reaches the end of its life the consultants say it should be capped to contain any future environmental damage to the surrounding area. The report states, “Any new landfill facilities will be engineered to modern standards and include containment measures and environmental control facilities for both non-hazardous and hazardous wastes.”

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