e-Digest Statistics about: Inland Water Quality and Use
Groundwater quality
A network of groundwater sites (i.e. aquifers) for England and Wales is in the process of being developed by the Environment Agency (EA) as part of its review of groundwater monitoring. Similar networks are being developed in Scotland and Northern Ireland. At present some information is available for England and Wales from work carried out by the EA in relation to nitrates in boreholes which are used for abstraction for public water supplies or other processes. This information, however, relates only to boreholes experiencing nitrate levels close to or above 50mg/l, this level corresponding to that set by the EC Drinking Water Directive for water put into the public supply. Although some of the monitoring data selected are from public supply wells, the data do not reflect the quality of drinking water which is subject to treatment before consumption. Table 14 shows annual average concentrations of nitrates for 17 of these groundwater sites. As the selected sites are groundwater monitoring points experiencing elevated nitrate levels they are not representative of all aquifers, either in their immediate region or in England and Wales as a whole.
Information covering pesticides detected in groundwater in England and Wales has also been collated by the Environment Agency. Far fewer results are available for groundwater than for surface waters, and the available information does not cover every EA region in every year. Table 15 shows summary information relating to the pesticides most commonly found in groundwater. The vast majority of these pesticides were found in very small quantities. To illustrate the occurrence of pesticides in groundwater Table 15 shows the percentage of groundwater samples in which concentrations of pesticide exceeded 0.1 µg/l, (equivalent to the European Union drinking water standard) over the period 1998-2004. The data collated for 2004 indicate that atrazine was the pesticide most frequently found in groundwater at levels above 0.1 µg/l, (approximately 3 per cent of the samples), followed by bentazone (0.88 per cent) and mecoprop (0.74 per cent).
In Detail:
Further Information:
Data Tables:
- References, further reading and links to other resources:
- [10] Pesticides in the Aquatic Environment 1995. Environment Agency, Centre for Ecotoxicology and Hazardous Substances, March 1997
- Groundwater quality - background and data. Environment Agency
- Internet Links:
- For national and local information see:
- England and Wales, Water Quality: Environment Agency - Groundwater, Groundwater quality - background and data
- Scotland: Scottish Environment Protection Agency - Discharges to water
- Northern Ireland: Environment and Heritage Service
- Department of the Environment in Northern Ireland
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Page last modified: 16 February 2006
Page published: 16 February 2006