Negligible air quality impact of proposed thermal treatment facility

A newly published Environmental Impact Assessment (EIA) concludes that emissions from the proposed hazardous waste incinerator in Magħtab will have a negligible impact on air quality.

The study found that emissions from the plant at the Ecohive complex are expected to remain within regulatory limits under all scenarios.

The new thermal plant is being proposed on seven agricultural fields over an area of about 18,200sq.m to the east of the Magħtab and Għallis landfills.   

The project, intended to replace the existing Marsa Thermal Treatment Facility, will process a significantly higher volume of waste. The hazardous waste throughput is projected to exceed 10,000 tonnes per year by 2045. The current Marsa plant, built in 2007, was originally designed for animal waste but now faces capacity limitations. It currently processes approximately between 5,000 tonnes and 6,000 tonnes of hazardous waste annually, with weekly transport trips reaching 130 to 150 vehicles. Due to economic and operational constraints, upgrading the existing facility was deemed unfeasible compared to constructing a new, modern plant in Magħtab.

The new facility will process a wide range of waste streams, including carcasses, clinical waste, waste oils, abattoir by-products, and industrial chemicals. Initially, one processing line will be operational, with provisions for a second to accommodate future demand. Each line is designed to handle up to 1.2 tonnes of waste per hour, allowing for a total capacity of 7,000 tonnes per line annually.

The EIA report was drafted by AIS Environment Ltd.

Negligible impact on air quality expected

One of the main concerns outlined in the EIA is the potential impact of the facility’s emissions on air quality. A six-week baseline air quality monitoring exercise identified 55 receptor points in Magħtab, Naxxar, Pembroke, Swieqi, St Paul’s Bay, San Ġwann, and Mosta.

Three air quality models were tested to simulate different operational scenarios, including worst-case emissions. The assessment incorporated the use of Flue Gas Treatment (FGT) systems and Continuous Emission Monitoring Systems (CEMS) to regulate and monitor emissions.

The findings indicate that emissions of nitrogen dioxide (NO₂), particulate matter (PM₁₀ and PM₂.₅), and other pollutants are expected to remain within regulatory air quality limits under all scenarios. The study also compared projected emissions with the thresholds established under Directive 2008/50/EC on Ambient Air Quality and Cleaner Air for Europe, confirming that pollutant levels would stay below legal limits.

The study was based on a chimney stack height of 25 metres, following a previous study that compared three chimney stack heights – 25m, 30m, and 35m.

The study revealed no significant variations in air quality impact among the different stack heights, leading designers to opt for a shorter chimney to minimise visual impact and associated costs.

However, the cumulative impact assessment, which considered emissions from both the proposed Thermal Treatment Facility (TTF) and the adjacent Waste-to-Energy (WtE) plant, suggested that while most areas would not experience significant adverse effects, a minor increase in PM₁₀ concentrations could occur at one receptor located on agricultural land 0.43 km from the site. The EIA notes that this increase is unlikely to exceed acceptable limits but remains a factor to be monitored.

Noise is not expected to be a major concern during either the construction or operational phases of the project.

Benefits of relocation

The proposed TTF will span approximately 18,185sq.m and will include additional facilities such as a water treatment plant, administrative offices, a reception area for pet carcasses, and landscaped zones. The plant’s design allows for future expansion, with space allocated for a potential third processing line to accommodate increasing waste volumes.

The relocation to Magħtab aims to mitigate odour complaints from residents near the Marsa site while improving logistical efficiency by centralising waste treatment within the Ecohive complex.

The existing Marsa facility is expected to remain on standby but will not be upgraded to handle future demand.

The EIA concludes that with proper emission controls, the project will comply with environmental standards while addressing Malta’s growing hazardous waste treatment needs.

Ecological impact

The study also addresses environmental concerns related to excavations, particularly dust emissions, which could impact the coastline and the protected l-Għadira s-Safra site, especially on dry, windy days. Construction work may also disrupt bird populations.

If activities take place between March and August, breeding territories of the Sardinian Warbler and the Zitting Cisticola could be disturbed or lost. Additionally, if work occurs between March and July, up to two breeding pairs of the Blue Rock Thrush could be affected.

This disruption could lead to temporary displacement, reduced breeding success, and the loss of nest sites, potentially causing reproductive failure for all three species.