COMHAIRLE CONTAE ÁTHA CLIATH THEAS
SOUTH DUBLIN COUNTY COUNCIL

MEETING OF LUCAN / PALMERSTOWN / NORTH CLONDALKIN AREA COMMITTEE

Tuesday, April 28, 2026

QUESTION NO. 2

QUESTION: Councillor H. Farrell

To ask the Manager for the results to the test carried out late 2025/early 2026 by SDCC of the water source in Lucan Demesne that runs under the road at the end of Tandy's Lane, by the "Bath House" in Lucan Demesne, joining the River Liffey to the North, and to report back on the water quality and chemical composition. Using 18th C scientific sources, we may be able to use this information to prove (or disprove) that this is the original "spa" discovered during the 18th century, despite another spa water found near the Spa Hotel and a second in what is now the park beside Sarsfield Park, as the chemical composition of each differed slightly.

REPLY:

The surface water outfall at the 'Bath House' in Lucan Demense was sampled on 11th December 2025.  The results do not indicate the presence of ground water.

The out of specification results highlighted in bold, indicate some pollution entering from the surface water system in Lucan.

A desktop and mapping survey is being undertaken to locate the source of pollution.

Once completed the Water Pollution Team will try to identify the source of the pollution on site and stop it.

Ammonia  as N             0.10mg/l

COD                              19mg/l

Conductivity (20°C)        657µS/cm

E. coli                          31062 MPN/100ml

Nitrate                         2.87 mg/l as N

Nitrite                          0.024 mg/l as N

pH                               8.1

Phosphorus (React)   0.14mg/l as P

Suspended Solids         <5mg/l

TON                             2.89mg/l as N

Total B.O.D.                7mg/l

Total Coliforms             >48392 MPN/100ml

 Bold - Outside limits set in Surface Water (Amendment) Regulations 2019

 - >1000/100 ml E.coli (Good Quality Status, Bathing Water Quality Regs, SI 79 of 2008)