Hydro G Final report - Kildare.ie

Hydro-G FINAL REPORT
local fracturing of the bedrock. The general flow direction is towards the sea i.e. to the east;
however, local variations, conditioned by the presence of surface water channels, are likely.
2.2.2. Groundwater Quality
The general water quality in this limestone aquifer suggests very hard water with total hardness
between 350-480 mg/l CaCO3 and alkalinity of 300-350 mg/l CaCO3. Electric conductivities are also
high and can vary from 550-900 µS/cm. This water has a is calcium bicarbonate signature (GSI,
2007).
2.2.3. Water Levels
Very little data exists on water levels in the area. The only available data were provided by Intel
Ireland, which monitors groundwater levels within their site. These were not available as specific
values; however, extracts from the monitoring reports provided by Intel stated that there are no
trends in the groundwater level behaviour.
2.3. Hot Springs in the Kildare Area
A number of hot springs are reported in the Dublin Groundwater Body, which are aligned along the
Lucan – Celbridge transect. These springs were extensively studied in 1983 (Minerex, 1983) and are
associated with deep faults and/or synclines, which allow deeper and warmer water to surface. The
temperature in these springs are reported to range between 12.5-25 °C. Historical data from the
1970’s and 1980’s (Minerex, 1983) suggest high chloride and total dissolved solids content in springs
that are specifically associated with synclinal structures. The Spa Well at Leixlip Spa classifies as one
of these springs occurring close to the Celbridge Syncline. Water signature in these springs can be
mostly associated with sodium-chloride waters and is usually indicative of an older water age.
Historical data (Meagher, 1976) suggest that the Leixlip Spa Well contained also large concentrations
of iron, for which it was often referred to as a Chalybeate spring.
An assessment of flows in these springs (Minerex, 1983) suggests normal seasonal discharge
patterns with increased flows in spring and decreased in autumn which suggests groundwater flow
controlled by the hydrological cycle. Similar patterns were found in the monitored spring’s
temperature variations.
2.3.1. Historical Hydrochemical Data from Leixlip Spa Well
Burdon’s report on Irish geothermal potential (Minerex, 1983) provides a good overview of the
quality and annual characteristics of groundwater in the Leixlip Spa Well. The report contains
information on two springs within the Leixlip Spa site, one warm (Spa Well) and one cold. The latter
being sampled through a manhole, which implies that the spring and its channel were modified prior
to the study period which was carried out between 1981 and 1982. Hydro-G attempted to identify
the location of the cold spring and the sampling location, however this was unsuccessful. Some later
documentation, retrieved from the NPWS’s archive (Ecoserve, 2006), suggests a cold spring is
located in an area of the two ponds on the eastern side of the upper terrace of the Leixlip Spa,
approximately 50m downhill from the Spa Well.
Project No.: 07_136 -5-
Leixlip Spa