Bord na Mona Waste Composting Facility, Drehid
- Client: MDY Construction for Bord na Mona
- Value(€ million): €5m
- Completion date: 2012
- PUNCH services: Civil, Structural
This project is a Design & Build project which PUNCH carried out with MDY Construction Ltd on behalf of Bord na Mona at their existing waste facility at Drehid.
The purpose of the facility is to take organic waste and treat it so that it becomes a usable end product, which is used in agriculture. The process was designed by the specialist firm Waste Treatment Technologies (WTT), who are based in the Netherlands. These works will be capable of processing 25,000 tonnes per year of separately collected biowaste from households, food waste from the service industry and retail outlets, and other commercial biowaste.
When the waste material comes to the facility, the process separates the inorganic elements such as plastics and metals prior to treatment in the composting tunnels. There are 12 No. composting tunnels in the facility, measuring approx. 5m wide x 5m high x 25m long. These tunnels are cast in concrete, and the floor of the tunnels contain a network of pipes, cast into the floor, with spigots providing a passage for air which is pumped into the compost mix to aid the aerobic digestion process.
The tunnels are designed to operate at elevated temperatures of up to 70 degrees centigrade, and compost may be left in a tunnel for a week. The treated compost material is then given further treatment for 24 hours in a hygienisation tunnel before being loaded onto transportation. Leachate and condensate is collected and recycled in the process or taken to treatment and disposed. Biofilters located on top of the tunnel clean the air before discharge from the plant.
The design of the concrete is of a particularly high specification, which is needed in an environment of Ammonium Ions and Ammonium Sulphate at elevated temperatures in a moist environment. There is also a requirement for high mechanical durability, due to the high wear and tear aspect of the site operations.
The structural frame for the building had to be treated for corrosion protection in a severe environment.
Green roofs minimise water attenuation requirements and a grey water-recycling system reduces water demand.
The floor area of this building is 4,300m2.