The implementation of an Environmental Risk Management Programme at the Guanapo Landfill in Trinidad

About the project

TAUW has offered support for the development an Environmental Risk Management Programme (ERMP) for the Guanapo Landfill, Trinidad. The services were part of the long-term project ‘Development and implementation of a sustainable management mechanism for POPs in the Caribbean’ implemented by the United Nations Industrial Development Organisation (UNIDO). The project is a pilot for international good practice and knowledge on the implementation of Environmental Risk Management Programmes at non-engineered landfills in developing countries with a tropical climate.

The Guanapo landfill is located between Maturita river and the El Cedro stream at the foothills of the Northern Range in Trinidad, occupying a surface area of approximately 15 hectares. Residential and agricultural land use dominates the immediate vicinity of the landfill. The Guanapo Landfill started as a non-engineered dumpsite and has organically grown to its current size. No lining or other hydrological barriers are present underneath the waste body causing leachate to disperse uncontrolledly into the environment.

To achieve the ultimate aim of reducing the impact of the pollution from the Guanapo Landfill on its environment, TAUW provided the following services:

• Modelling of digital surface model (DEM) and digital terrain model (DTM) using data collected with drones
• Assessment of the geohydrological situation of the landfill, including modelling of hypodermic and surface leachate outflow
• Chemical analytical investigation of leachate quality over two opposing seasons assessing such pollutants as the following: persistent organic pollutants (POPs) (e.g., PCDD/F, chlorinated pesticides, PCB, PFAS), heavy metals, petroleum hydrocarbons, volatile halogenated hydrocarbons, phenolic compounds, ammonium, acute toxicity, and faecal coliform.
• Analysing the impact of the landfill on groundwater quality
• Development of a hydrological map of the first 15 km of the Maturita River and the El Cedro Stream, including the inventory of surrounding receptors and pollution sources
• A surface water quality investigation and risk assessment of the Maturita River and the El Cedro Stream
• Development of an updated conceptual site model of the Guanapo Landfill
• Drafting mitigation measures to reduce leachate outflow to the surrounding surface water
• Implementation of a risk communication plan for potentially affected population surrounding the Guanapo landfill
• Liaison with Trinidad authorities and other relevant stakeholders
• Field capacity building training
  
  

How did the cooperation with the client go? 

TAUW completed a detailed site investigation supporting the implementation of containment activities at the Guanapo Landfill. All project activities were completed in direct coordination with the client UNIDO.

For the successful completion of the project, TAUW worked symbiotically with the landfill operator Trinidad and Tobago Solid Waste Management Company Limited (SWMCOL), specifically during the on-site activities. The on-site activities were all completed under the supervision of TAUW.

Furthermore, a strong cooperation was established with the following stakeholders:

• The national project focal point of Project Working Committee (PWC) - the Ministry of Planning and Development
• Executive agency - the Basel Convention Regional Centre for Training and Technology Transfer in the Caribbean (BCRC-Caribbean)
• The Project Working Community, including the Environmental Management Authority (EMA), the Ministry of Health (Pesticides and Toxic Chemicals Inspectorate), the Water Resources Agency (WRA) and the Tobago House of Assembly (THA).
  
  

The results

The results of current site investigation showed that measures should be taken to reduce the inflow of hypodermic and surface leachate flow to the river to ultimately restore the aquatic ecosystem and prevent human health impacts. The potentially impacted population was made aware of the present contamination and the appropriate use of water from the El Cedro Stream and the Maturita (e.g., correct irrigation and use for recreation or bathing).