Details of Award
NERC Reference : NER/D/S/2003/00694
Prediction of nitrate and pesticide trends in chalk groundwater.
Grant Award
- Principal Investigator:
- Professor LJ West, University of Leeds, School of Earth and Environment
- Co-Investigator:
- Professor S Bottrell, University of Leeds, School of Earth and Environment
- Co-Investigator:
- Dr NE Odling, University of Leeds, School of Earth and Environment
- Grant held at:
- University of Leeds, School of Earth and Environment
- Science Area:
- Freshwater
- Earth
- Overall Classification:
- Freshwater
- ENRIs:
- Pollution and Waste
- Natural Resource Management
- Environmental Risks and Hazards
- Science Topics:
- Water Quality
- Pollution
- Hydrogeology
- Abstract:
- The research aims to improve our ability to predict the impact of agricultural activities, in particular fertiliser and pesticide use, on the pollution of groundwater. Groundwater from one of the UK's major aquifers (the Cretaceous Chalk) has been showing rising levels of pollution by nitrates and pesticides which leads to the need for the water to be treated before being used. Knowing whether water quality will continue to deteriorate would a) allow water companies to better plan their groundwater resource strategy and b) allow appropriate evaluation of the real costs to the UK of intensive agricultural and c) encourage the development of more 'groundwater friendly' usage of agrochemicals in sensitive areas. The research will also hopefully contribute to scientific knowledge concerning how substances such as pollutants move through fractured rocks. This has applications in other areas besides the agricultural contamination of groundwater; for example, in remediation of industrial groundwater contamination and in siting and design of waste disposal facilities such as landfill sites and nuclear waste repositories. The research involves measuring and predicting the time taken by pollutants to reach the saturated part of the Chalk aquifer. This is important because the upper, unsaturated zone of groundwater aquifers provides a buffer, in which pollutants applied at the ground surface may be delayed, degraded or attenuated before reaching the water table. Travel times will be measured by sampling waters entering an existing railway tunnel after having passed through the unsaturated zone of the Chalk, and by extracting pore fluid from cores taken from above the tunnel. This will allow us to measure the extent to which the tracers enter the matrix of the rock or pass quickly through the network of fractures (joints and faults in the rock). The natural tracers used will include the agrochemical nitrate which is one of the pollutants of concern, and a tracer that is present in rainfall but whose concentration varies seasonally (the stable isotope of hydrogen, deuterium), as well as artificial tracer dyes applied to the surface at specific locations. The spectrum of travel times obtained by direct measurement are only applicable directly to the site where measurements are proposed, so numerical modelling will be carried out in order to extrapolate the results to a wider area, and predict the future water quality in nearby groundwater abstractions. Numerical modelling will allow us to understand how the travel times measured depend on the characteristics of the rock (fracture network and matrix), and the path length (i.e. depth of the water table). Data on characteristics of the aquifer across a wider area can then be used to predict the range of travel times for particular well catchments. Knowledge of these travel times will allow us to predict the extent to which biodegradable contaminants (such as pesticides) will reach water supply wells, and predict whether nitrate levels are set to go on rising or are likely to have already peaked. These data will in turn allow more informed decisions concerning water supply planning, and regulation of agrochemical usage.
- NERC Reference:
- NER/D/S/2003/00694
- Grant Stage:
- Completed
- Scheme:
- EO Programmes Pre FEC
- Grant Status:
- Closed
- Programme:
- Connect B
This grant award has a total value of £27,182
FDAB - Financial Details (Award breakdown by headings)
| Total - T&S | Total - Other Costs | Total - Indirect Costs |
|---|---|---|
| £2,535 | £8,086 | £16,560 |
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