The British Geological Survey (BGS), together with a number of partners is undertaking an independent environmental monitoring programme to characterise baseline conditions across the Vale of Pickering in North Yorkshire, in the vicinity of a site close to Kirby Misperton (Third Energy, KM8) proposed for shale-gas exploration and production. The monitoring will include measurement of: water quality (groundwater and surface water), seismicity, ground motion, air quality including radon, and soil gas. The programme aims to establish the environmental baseline before any shale-gas explorations begin.
This report presents the results of a desk study to develop an initial summary of the post-Permian bedrock geology across the Vale of Pickering. It is a component and specific deliverable of the environmental baseline project. The bedrock deposits form a number of shallow aquifers that are used locally for drinking water supply and agriculture. A separate report considers the superficial geology.
The geological information in this report will form the basis for identifying aquifer dimensions and configurations, groundwater flow paths and potential contaminant migration pathways, as well as determining optimum locations for sampling and monitoring. It will also provide information to support the locating of new borehole infrastructure (suitable for groundwater sampling and seismometers) and will underpin the interpretation of acquired hydrogeochemical data.
Nitrate is necessary for agricultural productivity, but can cause considerable problems if released into aquatic systems. Agricultural land is the major source of nitrates in UK groundwater. Due to the long time-lag in the groundwater system, it could take decades for leached nitrate from the soil to discharge into freshwaters. However, this nitrate time-lag has rarely been considered in environmental water management. Against this background, this paper presents an approach to modelling groundwater nitrate at the national scale, to simulate the impacts of historical nitrate loading from agricultural land on the evolution of groundwater nitrate concentrations. An additional process-based component was constructed for the saturated zone of significant aquifers in England and Wales. This uses a simple flow model which requires modelled recharge values, together with published aquifer properties and thickness data. A spatially distributed and temporally variable nitrate input function was also introduced. The sensitivity of parameters was analysed using Monte Carlo simulations. The model was calibrated using national nitrate monitoring data. Time series of annual average nitrate concentrations along with annual spatially distributed nitrate concentration maps from 1925 to 2150 were generated for 28 selected aquifer zones. The results show that 16 aquifer zones have an increasing trend in nitrate concentration, while average nitrate concentrations in the remaining 12 are declining. The results are also indicative of the trend in the flux of groundwater nitrate entering rivers through baseflow. The model thus enables the magnitude and timescale of groundwater nitrate response to be factored into source apportionment tools and to be taken into account alongside current planning of land-management options for reducing nitrate losses.
This chapter contains sections titled:
Introduction
The Role of Groundwater
Groundwater Protection Needs and Objectives
Groundwater Chemical Monitoring
Groundwater Quality Assessment and Classification
Conclusions
References
Groundwater systems provide an important source of water supply as well as contributing baseflow to rivers, lakes and dependent ecosystems and so the impact of climate change on these systems needs to be understood. Calculating recharge to groundwater systems is, therefore, necessary to quantify what is typically one of the largest components of the groundwater balance. This study uses the national-scale recharge model developed for the British mainland and the 11 ensemble members from the Hadley Centre for rainfall and potential evaporation created by the Future Flows and Groundwater Levels (FFGWL) project to investigate the impact of future climate on groundwater resources. Changes to seasonal and monthly recharge for the 2050s and 2080s time slices have been produced for the whole modelled area and for river basin districts for England and Wales. Areal summaries and monthly time series of recharge values show a generally consistent trend of increased recharge in winter, decreased recharge in summer, and mixed pattern in autumn and spring. The work shows that increased winter rainfall is the main factor in increasing recharge. Water balance calculations reveal that over the 2050s and 2080s, the climate change "signal" predominates over the annual variability, which results in a clearer pattern of more recharge being concentrated in fewer months. This finding should prove useful for water resources planners to assess the resilience of groundwater resources to climate change. Further work is recommended to understand the sequencing of flooding and drought events and to the effects of soil health and land cover changes in the future analysis.
Abstract Effective management of groundwater resources during drought is essential. How is groundwater currently managed during droughts, and in the face of environmental change, what should be the future priorities? Four themes are explored, from the perspective of groundwater management in England (UK): (1) integration of drought definitions; (2) enhanced fundamental monitoring; (3) integrated modelling of groundwater in the water cycle; and (4) better information sharing. Whilst these themes are considered in the context of England, globally, they are relevant wherever groundwater is affected by drought.
Global-scale nitrogen budgets developed to quantify anthropogenic impacts on the nitrogen cycle do not explicitly consider nitrate stored in the vadose zone. Here we show that the vadose zone is an important store of nitrate that should be considered in future budgets for effective policymaking. Using estimates of groundwater depth and nitrate leaching for 1900-2000, we quantify the peak global storage of nitrate in the vadose zone as 605-1814 Teragrams (Tg). Estimates of nitrate storage are validated using basin-scale and national-scale estimates and observed groundwater nitrate data. Nitrate storage per unit area is greatest in North America, China and Europe where there are thick vadose zones and extensive historical agriculture. In these areas, long travel times in the vadose zone may delay the impact of changes in agricultural practices on groundwater quality. We argue that in these areas use of conventional nitrogen budget approaches is inappropriate.
The attention currently being focused on diffuse pollution has led to an increased recognition of the role of groundwater as a pathway for transporting diffuse pollution to surface waters. Understanding and managing this issue requires a good understanding of the spatial and temporal distribution of diffuse pollution in groundwater. This in turn requires a co-ordinated approach to groundwater monitoring, to obtain accurate and representative data. This paper describes a strategic framework for groundwater quality monitoring that has recently been developed by the Environment Agency of England and Wales. The framework is implemented in three main stages: assessment of drivers and objectives, planning and implementation. The national framework is currently being implemented by a series of detailed regional programmes. These are developed on the basis of catchment-scale groundwater quality monitoring units, which will be broadly consistent with groundwater bodies defined under the European Union (EU) Water Framework Directive. The monitoring network that results from the application of the framework is designed to provide background information on groundwater quality at a catchment scale. Separate monitoring programmes will be required for monitoring pollution associated with individual sites. This paper focuses on the strategic aspects of designing a monitoring network, rather than the technical details of obtaining representative and accurate data from individual sample points, and is illustrated by a case study of the process of design of such a catchment-scale monitoring system.
The British Geological Survey (BGS), together with a number of partners is undertaking an
independent environmental monitoring programme to characterise baseline conditions in the
south Fylde east of Blackpool in an area proposed for shale-gas exploration and production. The
monitoring will include measurement of: water quality (groundwater and surface water),
seismicity, ground motion, air quality including radon, and soil gas. The programme aims to
establish the environmental baseline before any shale-gas explorations begin.
This report presents the results of a desk study to develop an initial summary of the post-
Carboniferous bedrock geology of the south Fylde. It is a component and specific deliverable of
the environmental baseline project. The bedrock deposits form a number of shallow aquifers that
are used locally for drinking water supply and agriculture. A separate report considers the
superficial geology.
The geological information in this report will form the basis for identifying aquifer dimensions
and configurations, groundwater flow paths and potential contaminant migration pathways, as
well as determining optimum locations for sampling and monitoring. It will also provide
information to support the locating of new borehole infrastructure (suitable for groundwater
sampling and seismometers) and will underpin the interpretation of acquired hydrogeochemical
data.