JBA Consulting
We were asked by the Environment Agency to work with a manufacturing organisation in the Hartlepool area who
rely on groundwater, to establish whether their abstraction boreholes could be causing saline intrusion into the
Magnesian Limestone aquifer. The aquifer is classified as part of the Water Framework Directive (WFD) as being at
'poor status', due in part to saline intrusion.
Challenge
Assessing Potential Saline Intrusion in a Coastal Aquifer
Location: County Durham
Solution
To develop a good understanding of the historical and current pressures facing the aquifer we reviewed a range of
information which included: historical water level data to determine how groundwater movement in the aquifer has
changed over time; groundwater chemistry data provided by the Environment Agency to determine spatial and temporal
trends; and details of operational processes at the manufacturing site to understand typical trends in groundwater usage
and enable design of borehole pumping tests.
Date: 2016-2019
Client: Environment Agency
The coastal location of the aquifer combined
with a history of pumping through dewatering
of mine water within the deeper Coal
Measures, and historically high levels of
public supply abstraction in the area, make it
vulnerable to saline intrusion. This can lead
to long changes in groundwater chemistry
and deterioration in water quality. Historical
dewatering from the deeper Coal Measures
during mining activities in the South Durham
Coalfield to the west may have reversed the
natural groundwater gradient. As mining
ceased and water levels began to recover,
public water supplies commenced, making it
difficult to separate the signal of effects on
any water level or chemistry changes.
Baseline understanding of the freshwater-saline interface (assuming
no abstraction from the aquifer)
This project aimed to determine the degree to which historical activities within the aquifer are responsible for the
'poor groundwater status', and whether current groundwater abstraction for manufacturing purposes in the
Hartlepool area could be causing saline intrusion.