Emissions to land

Land is needed to generate energy, to grow crops, for mineral resources, to bury wastes, to support homes, industries, schools and hospitals, to support transport networks and for a great deal more. Land is a vital habitat for plants and animals. Land is used for leisure and recreation.
 
Many human activities and their by-products have the potential to damage land and particularly soils. Large and small industrial enterprises, the urban infrastructure, agriculture, horticulture, transport, from deliberate or accidental pollution incidents all affect land quality.
 
Soil is central to the environment. It stores and recycles nutrients and water, and provides the medium for crop growth; but it also acts a buffer between the atmosphere and aquatic ecosystems. This can only be maintained if we do not damage soil; once damaged or contaminated soil can be extremely difficult to repair and soils can themselves become sources of pollutants. Soil stabilisation and remediation is a route to managing contaminated soils.
 
To minimise the possibility of soil contamination through spills plants and quarries employ Environmental Management Systems and procedures. Emissions to land also occur in the form of waste from manufacturing processes. This is something that is being targeted throughout the concrete industry: making more with less. For instance, the cement industry has targets to:
  • Reduce the amount of cement-process-waste residues disposed of per tonne of cement produced.
  • Optimise the sustainable use of wastes from other industries or sources.
At the top of the waste hierarchy is the need to reduce the amount of waste that is produced. As with most
industrial processes, the cement industry produces waste that it must dispose of. There is a need to look at how
the amount of waste can be minimised as well as securing opportunities to recycle waste back into the process.
In these regards Cement Kiln Dust (CKD) is of particular concern to the cement sector because it constitutes a
high proportion of the total amount of waste generated.
 
There are also benefits to be had by replacing natural raw materials with waste that would otherwise need to be disposed of through e.g. landfill or incinerator, where such replacement is environmentally sustainable. Cement kilns are allowed to burn waste-derived substitute fuels where they cannot be technically and economically recovered or recycled further up the waste hierarchy.
 
This means that over the longer term there may be an optimum level of fuel substitution, determined by the availability of suitable waste streams and development of alternative options higher up the waste hierarchy. Development of guidance on the best practicable environmental options for specific waste streams, informed by Life Cycle Assessment, may assist in setting practical targets in the longer term.
 
Recycling construction waste
Construction and demolition activities generate around a quarter of all the waste produced by the UK. Concrete is just one of the principal waste materials involved; others are soil, ballast, asphalt, bricks, tiles, plaster, masonry, wood, metal, paper, glass and plastic. A high proportion of this waste can be recycled and re-used. Tools such as the landfill tax and the aggregates levy have helped boost such initiatives. It is good business sense to reduce wastage and to recycle waste where appropriate.