Baseline Scotland: groundwater chemistry data

Collecting new data on groundwater chemistry in Scotland to provide a scientific foundation to Scottish, UK and European water quality policy.

About Baseline Scotland

SEPA logo

Baseline Scotland is a joint project between BGS and SEPA which is providing new groundwater chemistry data for Scotland. This new data provides essential information to sustainably manage Scotland’s water environment, as required by Scottish, UK and European water legislation, (such as the Water Framework Directive). Before Baseline Scotland very little reliable groundwater chemistry data existed, particularly for trace elements.

Groundwater sampling is being carried out in different parts of Scotland each year, using standardised sampling techniques to characterise the groundwater chemistry in detail. This information can help indicate how long the water has been in the ground, how it has interacted with the rocks, and also whether there is any groundwater pollution. Baseline Scotland runs until 2011, by which time systematic groundwater sampling surveys will have been undertaken in all the major bedrock aquifers in Scotland.

The aims of Baseline Scotland are:

  • To characterise the natural background groundwater quality in the main aquifers of Scotland, by carrying out new detailed groundwater chemistry sampling.
  • To provide a scientific foundation to Scottish, UK and European water quality policy and groundwater management and protection, with an emphasis on the protection and sustainable development of high quality groundwater


  • Summarised groundwater chemistry data for the major bedrock aquifers in Scotland.

Spatial coverage of groundwater chemistry data: Scotland

Spatial coverage of groundwater chemistry data in Scotland, from samples collected prior to the Baseline project

Before the Baseline Scotland project began there was little information on natural groundwater chemistry in Scotland. Existing data was mainly old, of variable quality, limited (often to a few major ions only), and skewed to areas of groundwater contamination, particularly related to mining, and to the more productive Scottish aquifers, in particular the Devonian aquifers of Fife, Strathmore and Morayshire, and the Dumfries Permian aquifer — see map right.

Since the start of the Baseline Scotland project more than 170 new groundwater samples have been collected. A further 180 samples collected during other projects since 2001 have been incorporated into the Baseline dataset — see map right. There are still several areas where groundwater chemistry are scarce, and these areas will be targeted in more groundwater sampling surveys in the run up to 2010.

Baseline sampling

The Baseline sampling surveys are collecting new data on groundwater chemistry, stable isotopes and residence times. Rigorous well head measurements (of parameters including dissolved oxygen, redox potential, SEC and bicarbonate) are combined with collecting samples for analysis of major, minor and trace ions; stable isotopes (δH2, δ18O and δ13C); dissolved organic carbon; and where possible, CFC (chlorofluorocarbon), SF6 (sulphur hexafluoride), and other dissolved gases such as CH4 (methane).

Measuring wellhead chemistry.

Sampling groundwater.
Sampling groundwater.

Baseline data

Scottish Hydrogeological units

Seven hydrogeological units have been defined within Scotland on the basis of geological age and rock type. Many of these are widespread: for example, major outcrops of Devonian sedimentary rocks occur across the country. To enable effective data collection and interpretation, sampling survey areas were defined on a geographical basis as well as on the hydrogeological unit: so, for example, there have been separate Baseline investigations into Devonian sedimentary aquifers in Strathmore, along the Moray and Invernessshire coast and in the Borders. However, at the end of the project a synthesised interpretation of the chemistry of groundwater in each of the hydrogeological units (e.g. all the Devonian, or all the Permian aquifers) across Scotland will be produced. Click on the data links at top of this page to view summaries of groundwater chemistry data for Scotland.