Hydro geology on the Sandstone Ridge. Workshop slides presented by Gordon Coombs of AMEC

1. Hydrogeology Workshop
Introduction to Hydrogeology (6)
Groundwater Flow
How and why does it get out?
• Water table is intercepted by the ground-surface - pretty
obvious really.
But what else can encourage groundwater to
discharge at the surface?
– Boundaries and Barriers
• Impermeable geological layers;
• Faulted boundaries

2. Hydrogeology Workshop
Introduction to Hydrogeology (7)
Hydrogeolgy of the Ridge Area
What does all of this mean for the Sandstone
Ridge Area?
We will use what we have learnt to build a
conceptual model which illustrates how this
applies to the Sandstone Ridge Area.

3. Hydrogeology Workshop
Introduction to Hydrogeology (7)
Hydrogeolgy of the Ridge Area
Recharge. Bigger arrow,
more recharge
Groundwater in perched aquifer
quickly discharges to springs,
streams and ditches
Water tables are established in
small perched aquifers and the
main Sandstone aquifers.
Most of the groundwater in main aquifer flows from
east (high area) to west (low area) where much
discharges to rivers and streams
A small amount of
groundwater flows
toward the east and
could come in contact
with the salt
To the east, the Sandstones are deep
beneath the mudstones.
Groundwater is old, stagnant and
poor chemical quality.

4. Hydrogeology Workshop
Introduction to Hydrogeology (7)
Hydrogeolgy of the Ridge Area
Boreholes, Wells and Springs....
• Where might they be?
• How much water will you get?
• Who might have one?

5. Hydrogeology Workshop
Introduction to Hydrogeology (7)
Hydrogeolgy of the Ridge Area
A A A A
A. Spring sources. Usually moderate yields for domestic/small community supply. Can produce high yield in places.
B
B
B. Shallow wells/boreholes into small perched aquifers. Usually small yields. Mostly suitable for domestic supply.
C
C. Shallow wells/boreholes into extensive sands and gravel. Moderate yields (domestic) but could be high (aggregates
industry/gen industry/community supply). However, contact with rock salt etc may cause quality problems especially if
over-exploited/over-pumped.
DD1
D. Moderately deep boreholes into main Sandstone aquifers; fewer faults may mean lower yields but some sources may draw
additional water from rivers if nearby (D1). Some public water supply boreholes are here.
E E
E. Moderately deep to deep boreholes into main sandstone aquifers. Faulting, fractures and fissures are
common and yields can be very high. Most of the public water supply boreholes are here.
F
F. Very deep boreholes may generate decent yields (may also be artesian), but water quality is likely to be very
poor. Very few, if any, water supply boreholes into the Sandstones here.

6. Hydrogeology Workshop
Introduction to Hydrogeology (7)
Hydrogeolgy of the Ridge Area
Distribution of water wells/boreholes
from BGS records
Go to
http://www.bgs.ac.uk/discoveringGeology/geologyOfBrita
in/viewer.html
(Follow instructions for showing locations at rear of handout )

7. Hydrogeology Workshop
Part 3
What’s on Your Door Step?

8. Hydrogeology Workshop
What’s on Your Door Step? (1)
• Sources of Information
• Records and Record Keeping

9. Hydrogeology Workshop
What’s on Your Door Step? (2)
Sources of Information:
– Publications/BGS/Internet. Literature, Maps (geol, topo,
hydro), Borehole/well records, etc
– Regulatory Bodies. Environment Agency, Local authority
(Env Health Dept)
– Water Companies. (UU, STW)
– Historical maps/ Estate records
– Local Groups. Local History, Regional Group Geol Soc
– Local Knowledge. Methods of engagement, Anecdotal,
Press release, Internet.
– Other. Place names, road names, house names.

10. Hydrogeology Workshop
What’s on Your Door Step? (1)
Records and Record Keeping
An example well/borehole catalogue. Exercise using details from a
selection of actual borehole logs and maps to populate the
catalogue.