Aggregates Programme for Scotland – Production of high value aggregates from construction, demolition and excavation waste

Construction, demolition and excavation waste (CD&EW)


Recycled aggregate 0/40mm and higher quality soil
Added value products 20/40mm, 10/20mm, 4/10mm and 0/4mm
0/4mm Bagged washed sand


2003 - ongoing


Bowhill Restoration and Recycling facility, Lochgelly, Fife


WRAP’s Aggregates Programme for Scotland, launched in 2003, is funded by the Scottish Executive via the Aggregates Levy. Through the capital funding programme, WRAP aims to help increase Scotland’s reprocessing infrastructure and promote a more sustainable approach to resource use by increasing recycling capacity.

Realm Construction Ltd. already operated within a former open cast colliery at Lochgelly, Fife. With the support of WRAP, additional washing equipment and infrastructure was provided to be able to recycle construction, demolition and excavation waste that otherwise would have gone to landfill or been used as low quality fill material.


Phasing
Three grants for three phases were awarded, each grant paying for the addition of equipment and ability to generate different recycled materials. The supply and installation of machinery was carried out by a sub-contracted company, whilst installation of the required infrastructure works was carried out by a different provider.

The three phases were:
1) 2003: installation of equipment to facilitate the processing of a soil/stone mixture into recycled aggregate and higher quality soil. This enabled 60% of the waste to be recycled.
2) 2004: installation of equipment to facilitate the washing and screening of 0/40mm material leftovers from Phase 1 into the added value products of 20/40mm, 10/20mm, 4/10mm and 0/4mm material. This enabled a further 25% of the original material to be recycled.
3) 2006: installation of equipment to facilitate the conversion of the silt residue from Phase 2 into high quality, bagged, washed sand. This enabled a further 10% of the original material to be recycled.

The combination of the three phases enabled a total recyclability of at least 95% of the material entering Realm Construction’s facilities.

Materials and applications
90% of the construction, demolition and excavation waste material originates from other services offered by Realm Construction, such as demolition and excavation services. Had this recycling facility not been installed, the material would have gone to landfill or been used as a low-value fill material. Realm Construction’s facilities add value to the material to produce high quality washed and graded aggregates that can be used in a variety of ways.

Realm Construction’s Bowhill recycling facility produces products suitable for Type 1, 6F1 and 6F2 use. 20/40mm, 10/20mm and 4/10mm aggregates are generated, as well as 0/4mm washed screened sand, topsoil and manufactured soils.

228,000 tonnes of CD&E waste is set to be reclaimed by the Phase 1 recycling over 5 years; 58,000 tonnes of waste over 5 years is expected to be reclaimed by Phase 2 of the recycling facilities; and a further 75,000 tonnes of waste is anticipated to be reclaimed over 5 years by Phase 3. Realm Construction is currently on track to meet these targets.

Other Realm Construction Facilities on Site
Other facilities operated by Realm Construction are utilised when the opportunity arises. Realm Construction operates a variety of services on site which are unrelated to each other. However, certain aspects of these services are integrated so as to make the best use of all the material coming on and going off site. Waste materials from one service can make a satisfactory addition to the processes of another.

Where the phased aggregate recycling requires water, recycled water from elsewhere on site is used as much as possible. The recycled water comes from council gully washers who make use of Realm Construction’s water recycling facilities which use a series of reed beds to clean the water offloaded by the washers.

Realm Construction also recognises the efficiency savings in fuel consumption, time and environmental emissions by minimising haulage. Logistics are coordinated so as to prevent any empty lorry movements to or from the Bowhill site. The majority of haulage distances for the recycling facility are within a 30 mile radius of the site.

The efforts of Realm Construction at the Bowhill site have not gone unnoticed and they have received awards for the project:

• East of Scotland Medium Company (10 and 250 employees) – Scottish Environment Protection Agency VIBES Awards (2003) winner
• Water Efficiency Awards Commendation – Environment Agency Water Efficiency Awards (2005) finalist


This case study illustrates that by phasing the processing of material, waste is reprocessed until it is part of a saleable product. The waste of one phase is the input for another, and so on, until the construction, demolition and excavation waste delivered to Bowhill is as close as one can reasonably get to being 100% recycled into higher value applications.

Bowhill also showcases a holistic view of sustainability by the integration of the varied, services provided on site. Waste recyclability, resource use within the waste processing, and transport effects are all considered in the interactions between the site’s various services, and between the facility and its customers. In this respect, the customer’s involvement in these aspects of sustainability is also encouraged.

Download the full case study (220 kb) .