2. Groundwater Monitoring at Sellafield
Annual Data Review 2016
Date: 30/11/2017

3. Groundwater Monitoring Programme 2016
689 samples were collected from 204 sample locations distributed across site and land adjacent to the Site Licence Boundary
Samples were analysed for up to 26 radiological determinands, 16 inorganic determinands, banded hydrocarbons and organic determinands
91 results exceeded the 4σ for radiological determinands and 97 results exceeded the 4σ for non-radiological determinands
The majority of exceedances were short term jumps in concentration and did not indicate a significant change in groundwater chemistry
8 samples could not be collected as either the sample locations were dry, there was restricted access or monitoring well redevelopment work was being undertaken
15 samples could not have the full analysis completed due to reduced sample quality
Purpose of the slide:
High level outline on what the GWM sample programme looks like & the range of analysis completed
How many exceedances were reported during the year
Compliance – did we complete the sampling and analysis that the programme required?
Map – GWM network

4. Radiological and Non-radiological Results 2016
The spatial distribution of the higher activity concentrations of the radiological determinands are very similar to previous years, predominantly within Separation Area
Non-radiological determinands also indicated similar patterns in terms of spatial distribution and concentration in comparison with previous years’ results
This reflects both limited changes in subsurface water quality and the stability of the groundwater monitoring programme
Purpose of slide:
Summary of observations when reviewing the radiological data in terms of concentration and spatial distribution
Summary of observations when reviewing the non-radiological data in terms of concentration and spatial distribution
Example maps

5. Groundwater Chemistry 2016
The majority of groundwater can be classed as mixed with bicarbonate, calcium, chloride and sodium being the dominant ions
Saline water chemistry was identified at 16 sample locations
1 sample location, to the SW of Separation Area shows a nitrate signature
The data do not indicate that a specific groundwater type is restricted to a particular hydrogeological unit, or a particular depth
Purpose of slide:
Overview of major ion chemistry
GW is of mixed type
No obvious patterns in distribution of GW types
Map – GW types across site

6. Numerical Model
Comparison between the measured data and modelled data for strontium-90 is shown
The distribution is broadly similar with the higher activity concentrations within Separation Area
The full report will be available on the Sellafield area of the gov.uk website:
d-ltd-environmental-and-safety-reports