Construction of the Temporary Environmental Control Enclosure
Environmental controls are measures put in place to mitigate environmental impacts. The primary environmental control for the Macdonaldtown Gasworks Remediation was an Environmental Control Enclosure (ECE), that was constructed to cover the middle of the site where the most contaminated materials were excavated. The ECE included an Emission Control System (ECS), which filtered the air extracted from the enclosure.
The ECE was designed to:
- Be a temporary piece of infrastructure;
- Accommodate excavators and other plant of various sizes;
- Contain emissions of dust, odour and volatile contaminants generated by the excavations;
- Prevent storm water from entering the main work area;
- Limit the visual and noise impacts of the remediation activities; and
- Use sections of the newly constructed underground retaining walls for its footings.
Activities inside the ECE included:
- Excavation of contaminated materials;
- Stockpiling of the materials; and
- Loading of the materials into trucks to be disposed of at a licensed landfill.
The ECE had a footprint of 2,600m2. It was 15m high at its apex and 9m high at its eaves.
The ECE was constructed of steel trusses covered in a durable, weather-proof fabric. Large roller doors provided access for vehicles. When the doors were open, the risk of dust, odour and volatile emissions to the external environment was mitigated by fans known as ‘air curtains.’ The air curtains directed high volumes of air into the ECE to minimise the volume of air that could escape.
Environmental monitoring was conducted during the remediation to confirm the effectiveness of the environmental controls and to protect the health of workers and community members, and the surrounding environment. Levels of dust, including PM10, volatile organic compounds and noise were continuously monitored at the residential boundary.