Landfill remediation begins

While most Cayman Islands residents were sheltering at home during the COVID-19 pandemic lockdown, essential employees across the island were hard at work providing vital services and progressing strategic projects, including capping the main mound at the George Town Landfill. 

Even while the Ministry of Health, Environment, Culture & Housing was leading the country’s response to the public health challenges of the pandemic, project team meetings were going on behind the scenes to achieve a long-term solution for the country’s solid waste management. 

Remediation of the George Town Landfill began in May when teams started work on a test pad to inform measures for the full capping operation. 

Remediation 

The full remediation of the landfill will continue with covering the waste with a layer of fill material, followed by a layer of synthetic, low-permeability liner. This is then covered with more fill and finally with a layer of topsoil to support the growth of grasses and shrubs that will provide an attractive green surface that is resistant to erosion.  

Once complete, remediation will significantly reduce the risk of fires at the existing landfill. While the vegetated landfill cap will improve the appearance of the site, options for future use are still under consideration and it will take several years for the site to stabilise sufficiently. 

Remediation will also include landfill gas management, which involves a network of collection wells and pipes connected to a gas blower that will extract gasses from the waste mound. When the planned energy recovery facility is commissioned, the gasses will be collected and piped to the energy recovery facility for conversion to electrical power.  

Landfill gas collected while the energy recovery facility is under construction will be flared off to destroy odorous or noxious compounds as well as methane, which makes up approximately 50% of landfill gasses and is a significant greenhouse gas. 

The flare will be located beside the waste mound and stand approximately 10 to 15 feet tall. Landfill gasses will be burned within the flare stack to avoid a visible flame and ensure complete combustion.  

Throughout the process, safety and efficiency will be ensured by monitoring the landfill cap for gas emissions, controlling the gas extraction process by balancing the well field and adjusting the blower to sustain control of the collection process.

Environmental Impact Assessment 

The proposed integrated waste management system will be located in proximity to the existing facilities at the current George Town site. The integrated system will include various components designed to work together to significantly reduce the amount of waste that requires landfilling and will include an ERF that will recover electrical energy from the residual waste.

Because the policy, strategy and outline business case for the integrated solid waste management system went through a period of public consultation before receiving final government approval, the Environmental Impact Assessment will focus on the potential impact of the facilities. The Environmental Impact Assessment is expected to commence later this year. 

As part of the Environmental Impact Assessment process, the 21-day public consultation period is expected to occur later this year. This public consultation will provide an opportunity for residents of the Cayman Islands to review the terms of reference for the proposed Environment Impact Assessment, learn more about the technical details of the proposed facilities, and have their comments and concerns about the proposed Environment Impact Assessment addressed.

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This article appears in print in the August 2020 edition of Camana Bay Times.

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