The Quality of Drinking Water in Ireland

Transcription

1 The Quality of Drinking Water in Ireland A Report for the Year 2003 with a Review of the Period ENVIRONMENTAL PROTECTION AGENCY An Ghníomhaireacht um Chaomhnú Comhshaoil PO Box 3000, Johnstown Castle Estate, Co Wexford, Ireland Telephone: ; Fax: info@epa.ie Website: Lo Call:

2 Environmental Protection Agency 2004 All or part of this publication may be reproduced without further permission, provided the source is acknowledged. Although every effort has been made to ensure the accuracy of the material contained in this publication, complete accuracy cannot be guaranteed. Neither the Environmental Protection Agency nor the author(s) accept any responsibility whatsoever for loss or damage occasioned or claimed to have been occasioned, in part or in full, as a consequence of any person acting, or refraining from acting, as a result of a matter contained in this publication. The Quality of Drinking Water in Ireland A Report for the Year 2003 with a Review of the Period Authors: Mr. Darragh Page, Mr. Jim Moriarty, Ms. Yvonne Doris and Dr. Matt Crowe ISBN /04/750 Price: 26 ii

3 EXECUTIVE SUMMARY... VIII 1. INTRODUCTION THE EUROPEAN COMMUNITIES (QUALITY OF WATER INTENDED FOR HUMAN CONSUMPTION) REGULATIONS THE EUROPEAN COMMUNITIES (DRINKING WATER) REGULATIONS, PARAMETER BY PARAMETER ANALYSIS OF DRINKING WATER INTRODUCTION ALUMINIUM AMMONIUM TOTAL & FAECAL COLIFORMS COLOUR FLUORIDE HEAVY METALS IRON MANGANESE NITRATES NITRITE ODOUR TASTE PH TRIHALOMETHANES TURBIDITY CRYPTOSPORIDIUM THE EUROPEAN COMMUNITIES (DRINKING WATER) REGULATIONS, PARAMETERS WITH REVISED STANDARDS IN THE 2000 REGULATIONS SANITARY AUTHORITY RESULTS INTRODUCTION AND OVERVIEW CARLOW CAVAN CLARE...48 iii

4 3.5. CLONMEL CORK CITY CORK (NORTHERN AREA) CORK (SOUTH AREA) CORK (WEST AREA) DONEGAL DROGHEDA DUBLIN CITY DUNDALK DUN LAOGHAIRE-RATHDOWN ENNIS FINGAL GALWAY CITY GALWAY (COUNTY) KERRY KILDARE KILKENNY LAOIS LEITRIM LIMERICK (COUNTY) LIMERICK CITY LONGFORD LOUTH MAYO MEATH MONAGHAN NORTH TIPPERARY OFFALY ROSCOMMON SLIGO TOWN...78 iv

5 3.35. SLIGO COUNTY SOUTH DUBLIN SOUTH TIPPERARY WATERFORD CITY WATERFORD COUNTY WESTMEATH WEXFORD WICKLOW EPA AUDITS INTRODUCTION AUDITS CURRENT ISSUES INTRODUCTION RESPONSIBILITY FOR PRODUCING AND MONITORING DRINKING WATER CHLORINATION FLUORIDATION QUALITY IN RURAL WATER SCHEMES IMPLEMENTATION OF THE 2000 DRINKING WATER REGULATIONS IMPROVED COMMUNICATION CONCLUSIONS RECOMMENDATIONS MANAGEMENT OF DRINKING WATER SAMPLING, MONITORING AND REPORTING MANAGEMENT OF WATER TREATMENT SLUDGES COMMUNICATION INFRASTRUCTURE AND PLANNING EUROPEAN COMMUNITIES (DRINKING WATER) REGULATIONS ENFORCEMENT OF THE DRINKING WATER REGULATIONS SUGGESTED FURTHER READING v

6 Acknowledgements The help of those sanitary authorities which contributed data to the Environmental Protection Agency for the purposes of this report is gratefully acknowledged. Thanks are also due to EPA staff members Ms. Shirley Murphy, Ms. Eileen Carroll, Mr. David Smith, Ms. Niamh O Neill, Ms. Mary Frances Rochford, Ms. Avril Boland and Mr. Frank Clinton. vi

7 Abbreviations & Symbols Al Cd Co Co Co Cr Cu EPA F Fe Gr GWS HACCP Hg MAC mg/l Mn MRC na n/a NDSC NH 4 Ni NO 3 NO 2 NTU Pb PWS µg/l SMP WHO Aluminium Cadmium County County Council Chromium Copper Environmental Protection Agency Fluoride Iron Groundwater Group Water Scheme/Schemes Hazard Analysis Critical Control Points Mercury Maximum Admissible Concentration Milligrams per litre Manganese Minimum Required Concentration Information not available to sanitary authority and / or EPA Not applicable National Disease Surveillance Centre Ammonium Nickel Nitrate Nitrite Nephelometric Turbidity Units Lead Public Water Supply/Supplies Micrograms per litre Small Private Supplies/Wells World Health Organisation vii

8 Executive Summary Overview The classification of water as fit for human consumption is based on the European Communities (Quality of Water Intended for Human Consumption) Regulations, 1988, which give formal effect in Irish law to the EU Drinking Water Directive [80/778/EEC]. The Drinking Water Regulations cover a total of 53 bacteriological, chemical and physical parameters (there are also two further parameters for softened waters which fix Minimum Required Concentrations). For each of the 53 parameters specified in Irish law, an upper concentration limit (or maximum admissible concentration) is specified. Hence, a comparison between monitoring results from a drinking water tap and the upper concentration limits allows one to judge whether a supply is fit for human consumption. Persons producing drinking water must provide water, which conforms to the quality standards as laid down by the 1988 Regulations. Though up to 53 different quality standards exist, there is a smaller groupof core parameters,between8and15inall,whichformasuitablebasisonwhichthe potability of water may be generally assessed in the majority of cases. The drinking waters produced and distributed by local authorities are termed public water supplies (PWS) and in 2003 monitoring results were submitted to the EPA for 906 such supplies (or supply zones). Public water supplies produce by far the greater quantity of water (Figure 1) though the number of group water schemes far exceeds that of public water supplies. In 2003, the EPA received monitoring results for 1,805 group water schemes, representing a slight decrease in the number of schemes monitored compared to 2002 (when 1,913 schemes were monitored). It is estimated that there are over 5,500 group water schemes in Ireland, serving approximately 10% of the population. Group water schemes can be broken down into two distinct groups, those that obtain their water from the sanitary authority and distribute it themselves ( public group water schemes) or those that source and distribute their own water ( private group water schemes). Of the schemes monitored in 2003, 791 were public group water schemes while the remaining 1,014 were private group water schemes. In the year 2003, routine monitoring of drinking water supplies in Ireland consisted of the analysis of 26,987 samples which involved 235,042 individual determinations of the 53 parameters specified in the Regulations (an increase of over 7%). The Environmental Protection Agency (EPA) estimates that local authorities (also called sanitary authorities) produced and distributed 91.9% of the sampled drinking water with 8.1% of the water distributed by group water schemes (Figure 1). The EPA estimates that approximately 1,700,000 m 3 /day of water is produced by the sanitary authorities and the group water schemes. Furthermore, based on the details submitted to the EPA, the bulk of water supplied originates from surface water sources (Figure 2). This is particularly so for public water supplies whereas group water schemes tend to be slightly more reliant on groundwater or spring water. viii

9 Public Group Water Schemes 2.5% Private Group Water Schemes 5.6% Public Water Supplies 91.9% Figure 1: Population Served by Water Supplies Monitored in Groundwater 11% Spring 5% Unknown 1% Surface Water 83% Figure 2: Sources of Drinking Water in The overall level of compliance with the 53 drinking water standards for public water supplies and group water schemes in 2003 was 96.1%, an improvement of 0.2% compared to 2002 (Figure 4) 1. For public water supplies the overall compliance rate improved from 97.4% in 2002 to 97.7% in 2003 while the compliance rate in group water schemes improved from 91.5% in 2002 to 91.8% in Overall compliance is based on the number of individual tests for each of the 53 parameters specified in the Regulations that meet the standards. ix

10 Recent trends in the total number of exceedances for core parameters and compliance rates for the parameters for public water supplies and group water schemes are presented in Tables 1 and 2 as well as a breakdown of number of exceedances and percentage compliance for public and private group water schemes for The trend over ten years in the number of analyses for the core parameters is illustrated in Figure , ,000 No. of Tests 120,000 80,000 40, Year No. of Compliant Tests No. of Tests Exceeding the Standards Figure 3: Compliance with the 14 Core Parameter Drinking Water Standards 1994 to Tests Exceeding the Standards 3.9% Compliant Tests 96.1% Figure 4: Overall Compliance in x

11 Table 1: Total Number of Exceedances of the Core Parameters from 2001 to 2003 Public Water Supplies Group Water Schemes Exceedances 2 Aluminium Ammonium Colour Faecal Coliforms , Fluoride Heavy Metals Iron Manganese Nitrates Nitrites Odour ph Taste Total Coliforms 1,124 1, ,793 1,552 Turbidity Public Private Exceedances for Group Water Schemes for 2003 are listed in total terms first with the number of exceedances in public and private group water schemes then detailed. For example, there were 875 exceedances of the Faecal Coliforms standard in 2003, with 81 of these in public group water schemes and 794 in private group water schemes. xi

12 Table 2: Trends in Percentage Compliance for the Core Parameters from 2001 to Public Water Supplies Group Water Schemes Public Private Aluminium Ammonium Colour Faecal Coliforms Fluoride Heavy Metals Iron Manganese Nitrates Nitrites Odour ph Taste Total Coliforms Turbidity Key Indicators Overall Level of Compliance Recent trends in overall compliance with the standards for all 53 parameters are presented in Figure 5 for all supplies combined, public water supplies and group water schemes. The overall rate of compliance for drinking water supplies in Ireland has improved by 0.2% in 2003 to 96.1%. However, the compliance rate for public water supplies improved by 0.3% in 2003 to 97.7% but is up 0.7% over the three year period. Overall compliance in group water schemes improved by 2.2% over the period As in previous years water supplied by public water supplies is of a higher quality than that supplied by group water schemes. Within group water schemes, water supplied by public group water schemes is of a higher quality than that supplied by private group water schemes. xii

13 100% Percentage Compliance 95% 90% 85% 80% 75% Overall PWS GWS Figure 5: Overall Compliance with the Standards in all Supplies Combined, Public Water Supplies and Group Water Schemes. Total and Faecal Coliforms Coliforms may be present in a drinking water sample due to inadequate treatment, post treatment contamination or where there are excessive nutrients in the water. As such, the presence of coliforms in a drinking water sample indicates the failure of the supply or distribution systems. Compliance in public water supplies improved slightly by 0.1% in 2003 to 93.4%. There was also an overall improvement in the compliance rate in group water schemes from 66.5% in 2002 to 67.1% in When examined on a scheme by scheme basis, 69.0% of public water supplies and 53.8% of group water schemes monitored were compliant with the standard for total coliforms. For the 2003 returns, all local authorities were asked to distinquish between public group water schemes and private group water schemes. This allowed a comprehensive assessment of the group water scheme sector and further pinpoints where the quality deficiency arises. In terms of the number of samples analysed, public group water schemes were of far superior quality than private schemes. The compliance rate with the total coliform standard for private group water schemes was just 54.7% in 2003 compared to 86.3% in public group water schemes. On a scheme by scheme basis, just 39% (392 of 1005 schemes monitored) of the private group water schemes complied with the standard for total coliforms during 2003 while 79% of the public schemes (569 of 781 schemes monitored complied). xiii

14 100% Percentage Compliance 90% 80% 70% 60% 50% Year Public Water Supplies Group Water Schemes Figure 6: Percentage of Samples Free from Total Coliforms over the Period 1994 to Not all coliforms are of faecal origin and to obtain a better picture of the quality of water in a supply a test is carried out to determine whether the coliforms detected are of faecal origin. The presence of a faecal coliform in a water supply is a definite indication that faecal contamination (human or animal) of the water supply has occurred. There has been a welcome reduction in the overall number of samples contaminated with faecal coliforms in The overall compliance rate for faecal coliforms improved from 94.2% in 2002 to 94.7% in The number of samples containing faecal coliforms reduced to 196 (down from 235 in 2002 and 422 in 2001) in public water supplies and to 875 (down from 887 in 2002 and 1,073 in 2001) in group water schemes. The net result is an improvement in the compliance rates for public water supplies to 98.7% in 2003 (up from 98.4% in 2002) and for group water schemes to 83.2% in 2003 (up from 80.9%), as illustrated on Figure 7. However, the compliance rate in public group water schemes was 96.1% in 2003 while it was just 74.9% in the private group water schemes (Figure 7). It is also worth noting that the compliance rate for faecal coliforms in public water supplies serving greater than 5,000 people was 99.7% (compared with 99.3% for 2002). As with the total coliform group of organisms the main reason for the lower rate of compliance with the faecal coliform standard in the group water sector is due to the poor quality of private group water schemes in comparison to the public group water schemes. xiv

15 100% 80% 60% 98.7% 96.1% 74.9% 40% 20% 0% PWS Public GWS Private GWS Figure 7: Percentage Compliance with the Faecal Coliform standard in Public Water Supplies, Public Group Water Schemes and Private Group Water Schemes. Though the continued improvement in compliance with the faecal coliform standard is welcome, the presence of faecal coliforms in any water supply at any time is unacceptable. Analysis of the exceedances of the faecal coliform standard on a supply by supply basis indicate that 788 (88.8%) public water supplies and 1,358 (76.1%) group water schemes were free of faecal contamination during This is a slight improvement from 2002 where 84.6% and 74.1% of public water supplies and group water schemes respectively were free of faecal contamination. However, this still means that 112 (11.2%) public water supplies and 426 (23.9%) group water schemes exhibited some degree of faecal contamination during The majority of these exceedances were moderate in nature though exceedances in 33 of the public water supplies were serious (down from 45 in 2002). Of the 426 group water schemes that were contaminated with E. coli during 2003, 366 of these schemes were privately sourced. Thus, of the group water schemes 92% (667 of 781) of the publically sourced schemes complied compared to just 63.5% of the privately sourced schemes (638 of 1004). xv

16 100% Percnetage Compliance 90% 80% 70% 60% 50% Year Public Water Supplies Group Water Schemes Figure 8: Percentage of Samples Free From Faecal Coliforms Over the Period 1994 to A summary of compliance with the faecal coliform standard in both public water supplies and group water schemes is presented in Table 3. Thirteen sanitary authorities achieved 100% compliance with the faecal coliform standard in public water supplies in 2003 (one more than in 2002). Compliance was greater than 99% in a further 8 sanitary authorities. Group water schemes in 3 sanitary authorities also achieved full compliance with the faecal coliform standard. Table 3. Summary of Faecal Coliform Compliance in Public Water Supplies and Group Water Schemes in Public Water Supplies Public Group Water Schemes Private Group Water Schemes Sanitary Authority No. of Supplies % Compliance No. of Supplies % Compliance No. of Supplies % Compliance NATIONAL AVERAGE Carlow Clonmel Cork City Ennis Town Fingal Galway City Kildare Laois Limerick City South Dublin Waterford City Wexford Dublin City Dun Laoghaire Rathdown Leitrim xvi

17 Public Water Supplies Public Group Water Schemes Private Group Water Schemes Sanitary Authority No. of Supplies % Compliance No. of Supplies % Compliance No. of Supplies % Compliance South Tipperary Sligo Town Cork (South) Westmeath Meath Offaly Longford Limerick County Clare Kilkenny Donegal Dundalk Town Sligo County Cavan Louth Wicklow Drogheda Town Monaghan Cork (North) Galway County Kerry Roscommon Mayo Waterford North Tipperary Cork (West) The Challenges Ahead The European Communities (Drinking Water) Regulations, 2000 (SI 439 of 2000) took effect on 1 st January 2004 and present a considerable challenge to the sanitary authorities charged with their implementation as well as operators of group water schemes and the private supplies that are now covered by the Regulations. These challenges include the establishment of a completely new monitoring and sampling programme and the requirement that each exceedance of a drinking water standard is investigated. Improvement in the group water scheme sector is occurring but the pace of improvement will have to accelerate considerably to ensure compliance with the 2000 Regulations. The exceptionally poor quality of the privately sourced group water schemes is clear to see and it is imperative that all privately sourced schemes be prioritised and included in investment programmes. Group water schemes that fail to engage in this process and the change that is required should be actively pursued by the sanitary authorities in accordance with Article 9 of the Regulations. In this regard, sanitary authorities must pursue non-compliant schemes and request them to prepare action programmes in accordance with the timeframes set out in the Regulations. New powers of prosecution under Article 14 should be utilised where progress is lacking in the preparation or implementation of these programmes. It is unacceptable that in 2004 a significant proportion of the population of Ireland is still receiving water that is not fit for consumption. xvii

18 Though there has been an improvement in public water supplies there are still a significant number of schemes that are supplying drinking water of an unacceptable standard. In particular the repeated failure of sanitary authorities to deal with supplies that breach the nitrate standard is intolerable. Sanitary authorities must deal with the small number of supplies that are repeatedly failing to meet the standards. The failure of treatment plants to meet the aluminium, colour and turbidity standards must also not be ignored. Though these parameters have been reclassified as indicator parametric values in the 2000 Regulations, they indicate that the treatment process is not operating adequately. The large number of supplies that repeatedly fail to meet the aluminium standard is unacceptable as aluminium is used as a treatment chemical and thus levels of aluminium in the final water are entirely under the control of the operator of that plant. Though not of concern in themselves the colour and turbidity breaches can indicate that there are other problems in the water supply (e.g. colour breaches may indicate THM formation and turbidity breaches may indicate an inadequately operating treatment system which may increase the risk of Cryptosporidium getting into the water distribution network). xviii

19 1. INTRODUCTION Public health and aesthetics (i.e., appearance, taste and smell) are the principal reasons underpinning the need for the treatment of water intended for human consumption. At the start of the 1900 s diseases such as cholera and typhoid fever prompted the development of water treatment technologies such as filtration and disinfection devices. In the 1970s there were significant developments in treatment technologies and this was coupled with an increasing understanding of the potential health effects of organic and inorganic substances present in drinking water. This has led to a broadening of what is understood by water fit for human consumption and a consequent need for more extensive monitoring of drinking water. The classification of water as potable (i.e., fit for human consumption) or otherwise is based on the European Communities (Quality of Water Intended for Human Consumption) Regulations, 1988 (S.I. No. 81 of 1988) which give formal effect in Irish law to the EU Drinking Water Directive [80/778/EEC]. These Regulations set standards for in excess of 50 parameters, which include microbiological, organic and inorganic standards. In Ireland, bodies whose function it is to provide drinking water are known as Sanitary Authorities and these comprise mostly County and Borough Councils as well as City and Town Councils. Regular sampling of water supplies is carried out by or on behalf of these authorities and the samples are analysed for a range of constituents, generally referred to as parameters of water quality. Testing covers physical, chemical and bacteriological aspects of water quality and the results form the basis on which the overall quality of drinking water can be assessed. The task of providing good quality drinking water, distributing it and assessing its quality as it reaches the consumer is the responsibility of the relevant sanitary authority. The Environmental Protection Agency (EPA) has statutory responsibilities in regard to drinking water. Section 58 of the Environmental Protection Agency Act, 1992, requires the Agency to prepare and submit to the Minister for the Environment, Heritage and Local Government a report each year on the monitoring by sanitary authorities of drinking water supplies and an assessment of the results. The present report, the fourteenth in the series, covers the year 2003 and gives a comparative assessment of data for the period The analytical data on which this report is based is generated by sanitary authorities by virtue of their monitoring programmes under the European Communities (Quality of Water Intended for Human Consumption) Regulations, In the report, quality variations on a national basis are considered, emphasis being placed largely on a parameter-by-parameter assessment. The report presents information on 15 key parameters, and provides a summary overall assessment of drinking water quality in each sanitary authority area. More detailed analysis of the monitoring data submitted by the sanitary authorities is included on the CD ROM version of The Quality of Drinking Water in Ireland: A Report for the Year THE EUROPEAN COMMUNITIES (QUALITY OF WATER INTENDED FOR HUMAN CONSUMPTION) REGULATIONS 1988 The European Communities (Quality of Water Intended for Human Consumption) Regulations, 1988 (S.I. 81 of 1988) gives formal effect in Irish law to the EU Drinking Water Directive [80/778/EEC]. Chief among the requirements of the 1988 Regulations are the following: all water for human consumption, whether in its original state or after treatment, regardless of origin, is covered, including water used in the food industry but excluding natural mineral waters or medicinal waters; national quality standards, the legal limits which must not be exceeded, are fixed for over 50 parameters; in particular circumstances, and only where there is no risk to public health, the Minister for the Environment may grant departures [exemptions] from the standard set for particular parameters; 1

20 minimum frequencies of sampling and analysis, for the respective groups of parameters which are also defined, are established by the Regulations. Samples are to be taken from water at the point where it is made available to the consumer; that is, at the consumer s tap. With regard to remedying water quality deficiencies confirmed by sampling and analysis, the requirements of the 1988 Regulations were subsequently supplanted by those of the European Communities (Quality of Water Intended for Human Consumption) (Amendment) Regulations, 1999 (S.I. No. 350 of 1999), which are broader in their coverage. However, it was subsequently decided that further Regulations would be required to deal comprehensively with the problematic private supplies and in June 2000 the European Communities (Quality of Water Intended for Human Consumption) (Amendment) Regulations, 2000 (S.I. No. 177 of 2000) were made. These Regulations were further amended in June 2003 (the European Communities (Quality of Water Intended for Human Consumption (Amendment) Regulations, 2003 (S.I. No. 259 of 2003) in response to a Judgement of the European Court of Justice on 14 th November, 2002, which found that the transposing Irish legislation failed to reflect the binding character of the requirements of Annex 1 to the Directive in relation to group water schemes. The 2003 Amendment Regulations placed a binding responsibility for the preparation and implementation of corrective action programmes on the sanitary authorities in relation to public water supplies and on the operators/trustees of group water schemes. Failure to adhere to the requirements of a notice served on the operator/trustee of a group water scheme could result in fines of up to 3,000 and/or up to six months imprisonment. These Regulations were effective until 31 st December 2003 whereupon there were replaced by the European Communities (Drinking Water) Regulations, 2000 (S.I. 439 of 2000). The 1988 Regulations also address the frequency of sampling and analysis. The basic principle underlying the monitoring is that the extent to which sampling and analysis are carried out increases with the magnitude of the populations served by the respective supplies. Table 1-1 below (taken from the Regulations) shows the population bands and the minimum analysis frequencies specified for each. Table 1-2 provides a description of the monitoring requirements referred to in Table 1-1. These cover populations from 1,000 to 1,000,000 people (assuming a daily per capita consumption of 200 litres). Only in two cases does the frequency remain to be determined by the sanitary authorities. Volume of water produced /distributed m³/day (a) Table 1-1. Minimum Frequency of Standard Analysis Required by the Regulations. Population Concerned (on basis of 200 l. per person per day) Minimum Number of Samples per Year ANALYSIS C1 C2 C3 C , (a) 500 2, (a) 1,000 5, ,000 10, ,000 50, , , , , , , , , ,000 1,000, Frequency to be determined by the sanitary authority as the situation requires Frequency to be determined by the sanitary authority but the requirement in article 7 (5) shall also apply. [ The requirement, mentioned above, is that water used in the food industry and effecting the wholesomeness of the foodstuff in its finished form shallbemonitoredatleastonceayear] 2

21 Table 1-2. Schedule of Parameters to be Monitored. Minimum Monitoring/ Analysis C1 (1) Odour Taste Conductivity (2) Total Coliforms or Total Counts at 22 C and 37 C Faecal Coliforms Current Monitoring/ Analysis C2 (1) Odour Taste Temperature Conductivity (2) ph Nitrates Nitrites Ammonia Total Coliforms Total Counts at 22 C and 37 C Faecal Coliforms Periodic Monitoring/ Analysis C3 (1) Current monitoring (C2) analyses plus other parameters determined by the sanitary authority having regard to all factors which may affect the quality of drinking water supplied to users and which may allow the ionic balance of the constituents to be assessed (1) Designations are those contained in the Regulations. (2) Or other physico-chemical parameter. (3) Monitoring in special situations or in case of accidents Occasional Monitoring (3) / Analysis C4 (1) The sanitary authority to determine the parameters according to circumstances, taking account of all factors which might have an adverse effect on the quality of drinking water supplied to consumers The monitoring requirements are quite clear for all supplies for populations over 1,000 persons and can be regarded as the lowest permissible frequencies. However, there is a most important proviso. Considerably more monitoring may be required in the following circumstances: (a) where past monitoring has indicated quality problems, (b) where there is a significant degree of variability in the water quality parameters and (c) where water requires to be disinfected as specified in Article 7(6) of the 1988 Regulations. It follows that such extra monitoring may be confined to those parameters which are particularly relevant in a given situation. It is also most important that monitoring should be continued for any parameter in respect of which a departure has been granted by the Minister. In such cases it is recommended that the parameters involved should be monitored at least at the minimum frequency for C1 analysis. As noted above, the Regulations state that, in the case of supplies serving fewer than 1,000 people or producing or distributing less than 200 cubic metres of water per day, monitoring shall be "on such occasions and to such extent as [the sanitary authority] shall consider necessary having regard to: (a) the patterns of standard analyses specified in Table A of Part II of the Schedule (Table 1-1), (b) their knowledge of the quality of water in their functional area, and (c) any factors, coming to attention which are likely to cause deterioration of quality. The implementation of the Regulations for supplies serving fewer than 1,000 people needs careful consideration as, under the Regulations, the sanitary authorities have specific responsibilities for all water supplies, including wells serving single households. For the purposes of this report, a reference to Regulations/standards is a reference to the 1988 Regulations/standards (unless otherwise stated) THE EUROPEAN COMMUNITIES (DRINKING WATER) REGULATIONS, 2000 The EU adopted a new Drinking Water Directive (98/83/EC) in November 1998 and this was transposed into Irish law on the 18 th December, 2000 as the European Communities (Drinking Water) Regulations, 2000 (S.I. 439 of 2000). Ireland was one of the few EU countries to have transposed the Directive before the specified deadline of 25 th December This set of Regulations is radically different from its predecessor and entails very significant changes in virtually all aspects of implementation - sample numbers, parameters, parameter classes, extent of coverage, and so on. It is important to note that the commencement date for the new Regulations was 1 January 2004 and thus the sanitary authorities should be implementing the 2000 Regulations at the present time. 3

22 The 2000 Regulations: set standards in relation to the quality of water intended for drinking water, cooking, food preparation, other domestic purposes and food production (other than natural mineral waters, bottled water, certain medicinal products and exempted supplies); provide for temporary departures from the standard where there is no threat to human health; and require that information is made available to consumers in relation to various matters including water quality, exempted supplies, departures granted, precautionary measures and remedial action in case of non-compliant supplies. In general, a wide ranging overhaul of the original 1988 Regulations has been carried out. As well as introducing a series of new or revised standards, termed parametric values, and downgrading some existing standards to indicator status, the new Regulations introduce a revised regime for correcting breaches of standards. The Regulations prescribe 48 parametric values which are classified as being either microbiological, chemical or indicator parameters. New parameters include E. coli, Enterococci, acrylamide, benzene, benzo(a)pyrene, bromate, 1,2 dichloroethane, epichlorohydrin, polycyclic aromatic hydrocarbons, tetrachloroethene and trichloroethene, trihalomethanes, vinylchloride, Clostridium perfringens, tritium and total (radioactive) indicative dose. It is noted that the standards specified in the new Regulations for ammonium and fluoride are more stringent than those specified in the 1998 Directive. Parameters no longer specified are faecal coliforms (replaced by E. coli), barium, magnesium, organochlorine compounds, phosphorus, potassium, silver, surfactants, zinc, alkalinity, calcium, dry residues, hydrogen sulphide, kjeldhal nitrogen, phenols, substances extractable in chloroform, suspended solids, temperature and total hardness. The two monitoring categories are respectively designated check monitoring and audit monitoring, the latter requiring the fewer number of samples but being by far the more demanding in analytical terms. The purpose of check monitoring is to provide information on the organoleptic and microbiological quality of the water supplied for human consumption as well as information on the effectiveness of drinking-water treatment (especially of disinfection) where it is used. The purpose of audit monitoring is to provide the information necessary to determine whether or not all the standards specified in Part I of the Schedule to the Regulations are being complied with. All such parameters must be subject to audit monitoring unless it can be established by a sanitary authority, for a period of time to be determined by it, that a parameter is not likely to be present in a given supply in concentrations which could lead to the risk of a breach of the relevant parametric value. Table 1-3 provides the minimum sampling frequencies that apply. 4

23 Table 1-3: Minimum Monitoring Frequencies Volume of water distributed or produced each day within a supply zone (m 3 ) Estimated Population Served Check monitoring Number of samples per year Audit monitoring Number of samples per year > To be determined by the sanitary authority >100 1, , >1,000 10,000 >5,000-50,000 >10, ,000 >50, ,000 >100,000 >500, for each 1,000 m 3 /d [5,000 pop] and part thereof of the total volume for each 3,300 m 3 /d [16,500 pop] and part thereof the total volume 3 +1 for each 10,000 m 3 /d [50,000 pop] and part thereof of the total volume for each 25,000 m 3 /d [125,000 pop] and part thereof of the total volume Other features of the Regulations include: the applicability of the Regulations to all supplies supplying greater than 10 m 3 /d (or > 50 persons) as well as to those supplies serving less than 10 m 3 /d but that supply water as part of a commercial or public activity; the assignment to the EPA of the function of granting departures from the standards as of 1 st January 2004; the introduction of time limits for compliance with the standards by public and private suppliers; the provision for offences and penalties in the case of private water suppliers which fail to comply with a notice served by a sanitary authority. A guidance note entitled European Communities (Drinking Water) Regulations, 2000: A Handbook on Implementation for Sanitary Authorities has been published by the Agency to assist sanitary authorities in the implementation of the Regulations. This Handbook can be purchased from the EPA Publications Office, McCumiskey House, Richview, Clonskeagh Road, Dublin 14 or can be downloaded from the Public Authority Enforcement section of the EPA website ( 5

24 2. PARAMETER BY PARAMETER ANALYSIS OF DRINKING WATER 2.1. INTRODUCTION The classification of a water as potable (i.e., fit for drinking) or otherwise is based on the requirements of the Drinking Water Regulations, The Drinking Water Regulations cover a total of 53 bacteriological, chemical and physical parameters for each of which an upper concentration limit or MAC [Maximum Admissible Concentration] is specified. There are two further parameters for softened waters which fix Minimum Required Concentrations [MRC]. The relevance of the various standards depends in large part on the local circumstances, which apply to a given water supply. For example, if the source is a boggy surface water, consideration of colour and ph (i.e., acidity or alkalinity) may be important. In a mineral-rich area the presence of iron or manganese may be a major influence on quality. If the water is supplied, say, to a block of older urban houses with metallic piping the presence of lead may be an issue. As a general rule in Ireland, the most important standards are those which relate to contamination by sewage or animal slurries. The relevant standards are those for Total Coliforms and Faecal Coliforms, though others may also be applied in particular circumstances. This chapter provides details of the extent of compliance (or otherwise) with the Regulations for 15 principal water quality parameters. Details are also provided of the results of the monitoring for trihalomethanes and Cryptosporidium though these are not included as part of the current set of Regulations. In an attempt to put the 15 principal water quality parameters into context, a brief background description for each parameter is presented along with a categorisation of any exceedance, which occurs into one of four bands. The bands are intended to indicate in approximate terms moderate, serious, very serious and gross degrees of contamination. The bands are customised for each parameter, taking account of the maximum admissible concentration as set out in the Regulations. Thus for example, the maximum admissible concentration for faecal coliforms is 0 mg/l and any exceedance for this parameter is divided into one of the following four bands as shown in Table 2-1. Table 2-1. Classification of Faecal Coliform Exceedances. Band Concentration Type of Exceedance 1 20 Moderate 2 >20and 200 Serious 3 > 200 and 500 Very Serious 4 >500 Gross The discussion below deals largely with exceedances of the Drinking Water Regulations. Where exceedances occur, it is essential that the sanitary authorities address them. However, there are clearly degrees of gravity in the effects for the health and well-being of the public who consume drinking water. The consequences of supplies which, say, contain one or two total coliforms per 100 ml, on the one hand, and hundreds of faecal coliforms, on the other will be significantly different. It should not be inferred from this example that the EPA condones minor exceedances of the standards. On the contrary, what this report seeks to present is an objective statement of the facts derived from the sanitary authority monitoring activities, and to set the analytical details in perspective. 6

25 2.2. ALUMINIUM Aluminium is one of the most abundant elements in the earth s crust. A salt, aluminium sulphate, is very widely used for colour and colloid-removal in the treatment of waters for drinking. The World Health Organisation (WHO) suggests that human exposure to aluminium may occur through a variety of routes, with drinking water probably contributing less than 5% of the total intake. The WHO Guidelines for Drinking-Water Quality (Draft 3 rd Edition) states that On the whole, the positive relationship between aluminium in drinking water and Alzheimer s Disease, which was demonstrated in several epidemiological studies, cannot be discounted. However, strong reservations about inferring a causal relationship are warranted in view of the failure of these studies to account for demonstrated confounding factors and total aluminium intake from all sources. Taken together, the relative risks from Alzheimer s Disease from exposure to aluminium in drinking water above 100 µg/l (i.e., 0.1 mg/l), as demonstrated in these studies, are low A total of 8,643 samples were analysed for aluminium in 2003 which represented an increase of over one third on the previous year. The number of samples analysed in public water supplies remained essentially the same (5,565 samples in 414 supplies) while the number of samples analysed in group water schemes rose dramatically due to the inclusion of aluminium in the monitoring suite for the Rural Water Monitoring Programme. The number of samples analysed from group water schemes rose to 3,078 in 1,001 schemes (an increase of 280%). The overall level of compliance with the aluminium standard rose to 92.8% in 2003 from 92.0% in 2002 (Figure 2-1). The improvement was due to the increase in compliance with the standard in public water supplies which rose from 91.7% in 2002 to 93.2% in The drop in compliance in the group water schemes is due to the poor rate of compliance in the public group water schemes which receive their water from public water supplies (85.8% compared to 98.5% in private group water schemes). It is likely that the poor rate of compliance in public group water schemes is due to a combination of elevated levels of aluminium in the water received from the sanitary authority and inadequate maintenance of the mains (regular flushing of the mains will flush out aluminium deposits in the distribution network) % Compliance Public Water Supplies Group Water Schemes Figure 2-1. Aluminium Compliance in the Period 2001 to

26 % Exceedances >1.0 Band (mg/l) Figure 2-2. Distribution of Aluminium Exceedances over the Period 2001 to 2003 (measured as a percentage of the total samples analysed). Throughout the review period the majority of aluminium exceedances are in the moderate band (i.e. <0.2 mg/l); however, in 2003 there was an increase in the percentage of gross exceedances (>1.0 mg/l). Poorly performing plants include Youghal Regional (Cork South), Ballyshannon and Gortahork Falcarragh (both Donegal), Carrigallen and Drumkeeran (both Leitrim), Tullamore (Offaly), Louisburgh (Mayo) and Laragh/Anamoe (Wicklow). In each of these supplies less than one quarter of the samples analysed complied with the standard. Exceedances of the aluminium standard were most likely due to inadequate control over the alum dosing regime at the plant particularly where the source is an upland river and where there is no provision for raw water storage at the treatment plant. Inadequate flushing of the mains may also contribute to some of the exceedances reported. Monitoring for aluminium was undertaken in 41 sanitary authorities with full compliance achieved in just 9 of these. Poor compliance was reported in Donegal (66%), Galway County (50%), Leitrim (61%), Longford (75%), Mayo (61%), South Tipperary (77%) and Wicklow (76%). The rates of compliance for aluminium for public water supplies in each sanitary authority is shown on Figure

27 Figure 2-3. Aluminium Compliance in Public Water Supplies by County 9

28 2.3. AMMONIUM Ammonia is generally present in natural waters, though in very small amounts, as a result of microbiological activity which causes the reduction of nitrogen-containing compounds. When present in levels above 0.1mg/l N, sewage or industrial contamination may be indicated. From the viewpoint of human health the significance of ammonia is marked because it indicates the possibility of sewage pollution and the consequent possible presence of pathogenic micro-organisms. There was a moderate increase (4%) in the number of samples analysed for ammonium in 2003 due to an increase in ammonium monitoring in group water schemes (13% increase). In 2003 a total of 8,875 samples were analysed for ammonium, 4,668 in public water supplies and 4,207 in group water schemes. The overall rate of compliance improved to 99.0% in 2003 reversing the drop seen in Compliance in public water supplies remained essentially the same in 2003 as it was throughout the last three years at 99.7% (Figure 2-4). The compliance rate in group water schemes improved from 97.8% in 2002 to 98.3% in % Compliance Public Water Supplies Group Water Schemes Figure 2-4. Ammonium Compliance over the Period 2001 to Not only has there been an overall reduction in the number of exceedances of the ammonium standard there has also been a shift in the exceedances from gross, very serious and serious to moderate (Figure 2-5). In other words, the number of moderate exceedances has increased at the expense of the more serious breaches which is to be welcomed. Compliance with the ammonium standard remains high. Of the 41 sanitary authorities that monitored for aluminium in public water supplies 34 were fully compliant (the same as in 2002). In 2003, group water schemes in 18 sanitary authorities (of 29) fully complied with the standard. 10

29 % Exceedances <0.4 <0.6 <1.0 >1.0 Band (mg/l) Figure 2-5. Distribution of Ammonium Exceedances over the Period 2001 to 2003 (measured as a percentage of the total samples analysed) TOTAL & FAECAL COLIFORMS Faecal coliforms originate in human and animal waste. Total coliforms include faecal bacteria and also other bacteria with similar properties which originate in soil and are non-faecal. The risk of infection to consumers from drinking contaminated waters will vary depending on the numbers of pathogenic organisms present (i.e., the actual disease-causing organisms). The number of pathogens in a sewage-contaminated water depends on whether persons carrying the pathogens in their bodies (so-called carriers ) are present in the local population. As the latter is an unknown quantity, and as the positive identification of specific bacteria may be a very difficult task, an indirect approach is universally adopted. To ensure a high factor of safety when testing for coliform contamination, the practice has been to monitor indicator organisms. These, by definition, should be (a) easily detected and identified, (b) of the same origin as the pathogens (i.e., from the human or animal intestine), (c) present in far greater numbers than the pathogens, (d) present whenever the pathogens are likely to be present and (e) able to show the same or better survival characteristics than the pathogens and, of course, they must not be in themselves pathogenic. To date the universal indicator organisms have been coliforms, specifically Escherichia coli. These bacteria are of definite faecal origin (human and animal) and are excreted in vast numbers. Their presence in a water supply is taken as proof that faecal contamination has occurred and it is therefore a definite indication of the risk that pathogens may be present. The absence of these faecal coliforms indicates strongly the probability that pathogens are absent. Some coliform organisms are able to grow in soil and are not of faecal origin thus a second analysis is carried out for the presence of total coliforms, giving an indication of the general level of microbiological contamination of a water. In 2003, 14,907 samples were analysed for total coliforms in 887 public water supplies representing an increase of just over 0.5%. Compliance with the standard improved marginally from 93.3% in 2002 to 93.4% in 2003 (Figure 2-6). Twenty two sanitary authorities achieved compliance rates of greater than 95%, up from 18 in 2002) with full compliance achieved in Ennis Town Council and Galway City Council. However, compliance was less than 90% in Donegal, Dublin City, Kerry, Longford and 11