Select Committee on Environment, Transport and Regional Affairs Memoranda


Memorandum by the Environment Agency (CEM 56)

GROUNDWATER POLLUTION POTENTIAL OF CEMETERIES

BACKGROUND

  The Agency welcomes the Select Committee's inquiry into cemeteries.

  The Agency recognises that new cemetery developments or extensions to existing cemeteries can be emotive subjects with local residents. Of particular concern is the impact such developments may have on the environment. However, these worries are often disproportionate to the real environmental risks. Though less emotive, pet cemeteries raise similar issues.

  Under current legislation, the Local Planning Authority is the principal body controlling new cemetery developments under the Town and Country Planning Act 1990 and the Planning and Compensation Act, 1991. The Agency is a statutory consultee within the planning process for applications for new and extended cemetery developments. Planning consent is not required for the burial of individuals on their own land.

REVIEW OF POLLUTION POTENTIAL

  In order to provide guidance on the risks to groundwater from the burial of humans or animal carcasses, the Environment Agency commissioned a study of the pollution potential of cemeteries. This study concluded that UK cemeteries generally present no significant pollution threat, although local factors, such as geology, can increase the potential risk. Potential chemical contaminants that will be present include:

    —  dissolved organic carbon;

    —  ammonia;

    —  chlorides;

    —  sulphates; and

    —  alkali earth metals such as sodium.

  The use of arsenic as an embalming agent was banned in 1951. Current embalming chemicals appear to pose little threat. Formaldehyde, the chemical commonly used, degrades rapidly in the subsurface under typical environmental conditions. The potential for migration away from the site is therefore minimal.

  There is also a potential risk from microbiological contaminants including viruses, bacteria and pathogens. The potential for contamination by these agents is determined by their ability to survive in the subsurface, the size of the pores or fissures through which they may migrate and the depth of the water table. Shallow groundwater protected by only a thin unsaturated zone and composed of coarse grained or fissured materials is potentially vulnerable to contamination. In contrast, groundwater in finer-grained non-fissured material with a deep water table is better protected. In principle, because of their smaller size, viruses should be more easily transmitted through to the water table than the larger bacteria and protozoa.

  Sites with the greatest potential risk are large sites, with more than 200 burials per year, that are located in freely draining soils with a shallow water table. The risks from microbiological contaminants are believed to be minimal because these organisms generally have short lifespans and/or are filtered by soil or aquifer material. However, the presence of preferential pathways, such as fissures, may increase the risks.

  Where large cemetery sites are proposed, the Agency believes that a formal risk assessment should be conducted that takes into account the hydrogeological and geological conditions, proximity of receptors, such as water supply boreholes and springs, as well as other environmental factors. We do not believe this action is necessary for smaller burial sites (10 or less burials per year), including "green burials", unless there are boreholes and springs close to the site. The minimum distance to any borehole or spring should be 50 metres.

  The issue of "green burials" is an emerging one which has only been with us for a few years. Green burials differ from normal burials as a result of differences in the materials used for enclosing the body, commonly a cardboard container or a shroud instead of a coffin, the absence of embalming and the use of shallower burial depths, around 1.3 metres deep compared with typical1y 1.8 metres for a normal burial. In principle, the rate of decay from a green burial is relatively rapid due to the readily degradeable nature of the materials used.

SITE-SPECIFIC STUDIES

  There are few specific UK studies on the impact of cemeteries on groundwater quality. The Agency therefore, in collaboration with the British Geological Survey, has been investigating groundwater quality at two cemeteries; an old cemetery and an active site.

  The old cemetery was used between 1813 and 1875 and is believed to have contained in excess of 1,100 bodies. The study has concluded that it does not present a source of contamination.

  Preliminary results from the operating cemetery, which has been operational for 25 years, show evidence of bacterial contaminants in groundwater derived from corpses. Some of the boreholes outside the perimeter of the burial site showed evidence of contamination suggesting migration of contaminants in the groundwater. No viruses were detected. The measured concentrations were low indicating that the loading to the groundwater is relatively small or that degradation or attenuation is occurring. The results indicate that the potential risks to groundwater in general are minimal.

LEGAL POWERS TO PREVENT WATER POLLUTION

  A permit is not required for human cemeteries under water pollution or waste management legislation. However, if a cemetery were to cause pollution of groundwater, or other controlled waters, it is possible that action could be undertaken under the Groundwater Regulations 1998 or the Anti-pollution Works Notices Regulations 1999. The Agency would, however, only use these powers as a last resort where the pollution was significant and where other measures had failed.

GROUNDWATER PROTECTION PRACTICE

  The Agency's Policy and Practice for the Protection of Groundwater and supporting tools such as the Groundwater Vulnerability and Source Protection Zone maps can form the basis of an initial risk screening exercise. These are a starting point for a risk assessment and can identify areas where groundwater is inherently more sensitive to pollution from surface activities and where major potable abstractions may be at risk from such activities. The Agency would be opposed to large graveyards and animal burial sites within Zone 1 Groundwater Source Protection Zones. Guidance on animal burial sites is given in the MAFF Code of Good Agricultural Practice.

  The above points have not yet been incorporated into the Agency's policy. The Agency's groundwater protection policy and guidelines are currently under review and we are considering the incorporation of the following guidance in the revision of the policy document:

    —  no burials within Zone 1 Groundwater Source Protection Zones around a spring, well and borehole;

    —  a minimum distance of 250 metres from graves to wells, boreholes or springs used for water supply;

    —  a minimum distance of 30 metres from graves to other springs or watercourses;

    —  a minimum distance of 10 metres from graves to field drains;

    —  no burial into standing water and the base of the grave should be above the local water table.

  Adoption of these practices should avoid the need for site-specific assessments for the lower risk proposals (low burial rates and low groundwater vulnerability). Site-specific risk assessments are needed for higher burial rates and in areas where groundwater is inherently more vulnerable, in addition to the good practice measures noted above.

December 2000


 
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