COMHAIRLE CONTAE ÁTHA CLIATH THEAS
SOUTH DUBLIN COUNTY COUNCIL

MEETING OF LUCAN AREA COMMITTEE

Tuesday, November 25, 2014

QUESTION NO. 14

QUESTION: Councillor L. O'Toole

 "To ask the Council to request regular water analysis from Irish Water to ensure that the level of hardness and quality of water supplied is consistent for the Lucan area?"

REPLY:

Water samples are taken daily at random points within the SDCC water distribution network by Dublin City Council's central laboratory

These samples are tested for compliance with aver 50 microbiological, chemical and aesthetic qualities parameters, as required by EC Drinking Water Regulations and monitored by the EPA,  to ensure that public water supply is safe to drink.

Hardness (CaCo3) is not one of the parameters tested but pH (Hydrogen ion) is analyzed and this reflects the degree of alkalinity of the water.  A pH value of above 7 indicates alkaline conditions, 7 is neutral and below 7 is acidic.  The allowance range is between 6.5 and 9.5.  There is a pH analyser on the outlet of Peamount Reservoir, delivering water to the Lucan Area, which records daily pH data.  During normal supply conditions, i.e. outputting blended Leixlip/Ballymore Eustace water, the pH of the outlet water is typically 7-7.8.  When water supply was unblended from Leixlip the pH increases to 8.

The hardness of water leaving production/treatment plants is analysed and the following summarises the results.

Total Hardness	B’more/B’boden/ Roundwood/Stillorgan	Leixlip
mg/l CaCO3	50	150 - 300
°eH (Clarke or English Degrees)
°dH (German Degrees)
°fH (French Degrees)	5	15 - 30
Mmol CaCO3
American Hardness Degrees (ppm)	50	150 – 300