Environmental Enforcement

Drinking Water Audit Report

Local Authority: Mayo County Council Date of Audit: 06 October 2011

Plant{s) visited: Lough Mask Water Date of issue of 27 October 2011 Treatment Plant Audit Report:

File Reference: PAE2007/464

Auditors: Ms Derval Devaney

Mr Palrick McLoughlin

Audit Criteria: • The European Communities (Drinking Watel) (No. 2) Regulations, 2007.

• The EPA Handbook on lhe Implementation of the Regulations for Water Scrvices Authorities for Public Water Supplies (ISBN: 978-1-84095-349-7)

• The recommendations specified in the EPA Report on The Provision and Quality 0/ Drinking Water in Ireland.

• The recommendations of the previous EPA aud it report issued on 151 April 2008.

• The most recent audit progress report submitted by Mayo County Council dated 24 oh May 20 I1 .

• The Regulation 10(4) Direction issued to Mayo County Council on the 21" of Apri I 2009 .

MAIN FINDINGS

1.

ii.

iii.

iv.

Mayo County Council has not implemented the action programme as required by the Direction issued by the EPA on 21st of April 2009 and was not in compliance with the terms of the Direction on the day of the audit. The Lough Mask Water Orinking Water Plant continues to operate above its design capacity. 55% of the abstracted water continues to by-pass the coagulation, flocculation and clarification treatment stage at the Lough Mask Drinking Water Treatment Plant. Turbidity spikes of > 1.0 NTU are being observed at times after the filters when they are brought back into serv ice following backwashing. Other operational problems with the filters were also observed on the day of thc audit. THMs continue to exceed the parametric value in the Lough Mask PWS.

I. INTRODUCTION

Under the European Communities (Drinking Water) (No. 2) Regulations 2007 the Environmental Protection Agency is the supervisory authority in relation to the local authorities and their role in the provision of public water suppl ies. This aud it was carried out to assess the performance of the local authori ty in providing clean and wholesome drinking water and to assess compliance with the Regulation 10(4) Direction issued to Mayo County Council on the 21" of April 2009 under the European Communities (Drinking Water) (No. 2) Regulations, 2007

The opening meeting commenced at 10:00 am at the Lough Mask Regional Public Water Supply Drink ing Water Treatment Plant in Tourmakeady. The Council reported that the plant supplies

Drinking Water Audit Report

Environmental Enforcement

Local Authority: Mayo County Council Date of Audit: 06 October 20 I I

Plant(s) visited: Lough Mask Water Date of issue of 27 October 20 II Treatment Plant Audit Report:

File Reference: PAE2007/464

Auditors: Ms Derval Devaney

Mr Patrick McLoughlin

Audit Criteria: • The European Communities (Drinking Water) (No. 2) Regula/ions. 2007.

• The EPA Handbook on the Implementation of the Regulations for Water Scrvices Authorities ror Public Water Supp lies (ISBN: 978-1-84095-349-7)

• The recommendations specified in the EPA Report on The Provision and Quality 0/ Drinking Waler in Ireland.

• The recommendations of the previous EPA audit report issued on 151 April 2008.

• The most recent audit progress report submitted by Mayo County Council dated 24 oh May 2011 .

• The Regulation 10(4) Direction issued to Mayo County Council on the 2 1" of Apri I 2009.

MAIN FINDINGS

i. Mayo County Council has not implemented the action programme as required by the Direction issued by the EPA on 21st of April 2009 and was not in compliance with the terms of the Direction on the day of the audit.

ii. The Lough Mask Water Ol"inking Water Plant continues to operate above its design capacity. 55% of the abstracted water continues lo by-pass the coagulation, Oocculation and clarification treatment stage at the Lough Mask Drinking Water Treatment Plant.

iii. Turbidity spikes of > 1.0 NTU arc being observed at times after the filters when they arc brought back into service following backwashing. Other operational problems with the filters were also obscl'ved on the day of the audit.

iv. THMs continue to exceed the parametric value in the Lough Mask PWS.

1. INTRODUCTION

Under the European Communities (Drinking Water) (No. 2) Regulations 2007 the Env ironme ntal Protection Agency is the supervisory authority in relation lo the local authorities and their ro le in the provision of public water suppl ies. This aud it was carried out to assess the performance of the local authority in providing clean and wholesome drinking water and to assess compliance with the Regulation 10(4) Direction issued to Mayo County Council on the 21" of April 2009 under the El/rOpean Comnlllllilies (Drinking Walet) (No. 2) Regulations. 2007

The opening meeting commenced at 10:00 am at the Lough Mask Regional Public Water Supply Drinking Water Treatment Plant in Tourmakeady. The Council reported that the plant supplies

approximately 30,000 m' /day to an estimated population of 30,698. The design capacity for the plant is 27,300 m' /day. The scope and purpose of the audit was outlined at the opening meeting. The audit process consisted of interviews with staff, review of records and observations made during an inspection of the treatment plant. The following were in attendance during the audit. The audits observat ions and recommendation s are li sted in Section 2 and 3 ofthis report.

Representing Local Authority: (' indicates that person was also present for the c losing meeting)

Kieran Shay - Ballinrobe Area Engineer'

Martin Lamer - Plant Opcrator/Caretaker'

Representing the Environmental Protection Agency:

Derval Devaney - Inspector

Patrick McLough lin - Inspector

2. AUDIT OBSERVA TIONS

In view of the observations noted during the audit and listed below, Mayo County Council is recommended to carry out the recommendations outlined in Section 4 afthis report;

The audit process is a random sample on a particular day of a facility's operation. Where an observation or recommendation against a particular issue has nol been reported, this should not be constnled to mean thalthis issue is-fully addressed.

1. Source Protection

a. The Water Services Authority stated that it wi ll make contact with the re levant personnel within Mayo County Council who liaises with the Western River Basin District team to obtain the most recent information on the catchment in an effort to characterise and identify any risks from potential sources of pollution into the catchment of the regional water supply

b. The Water Services Authority informed the audit team that landowners within 250 m of the intake point have been informed of their obligations under SI 610 of 20 I 0 and protection measures are superv ised by the treatment plant technician and caretakers. A survey is to be carried out between 250 m and 1000 m of the intake to determine if additional contro l measures are required.

2. Coagulation, Flocculation and Clarification

a. The Water Services Authority stated that 45% of the abstracted water receives full treatment; 55% of the water continues to bypass the c larification stage, is then mixed with the clarified waler and passes through to filtration.

b. Ferric sulphate is added at a dose of between 110 mgll and 130 mgll and the dosing of ferric is gauged depending on the level of iron in the final water. The water is then dosed with po ly which varies from 0.13 to 0 .16 mgll.

c. Jar tests were increased to hi-weekly after the EPA's (lUdit in 2008 but due to similar resu lts being obtained, they are now carried out only when variat ions in water quality occur which is 2-3 times per year. Jar test results 3re recorded on-site.

d. The Water Services Authority stated that floc carry-over has decreased with the increased cleaning of the settling tanks which is carried out on a bi-annual basis. The tanks were last cleaned 6 weeks prior to the audit. Some pin-head Aoc was evident in the c larifiers on the day of the audit.

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approximately 30,000 m' /day to an estimated population of30,698. The design capacity for the plant is 27,300 m'/day. The scope and purpose of the audit was outlined at the opening meeting. The audit process consisted of interviews with staff, review of records and observations made during an inspection of the treatment plant. The following Were in attendance during the audi!. The audits observations and recommendations are listed in Section 2 and 3 of this report.

Rcpresenting Loca l Authority: (. indicates that person was also present for the closing meeting)

Kieran Shay - Ballinrobe Area Engineer'

Martin Lamer - Plant Operator/Caretaker·

Representing the Environmental Protection Agency:

Derval Devaney . Inspector

Patrick McLoughlin - Inspector

2. AUDIT OBSERVA nONS

In view of the observations noted during the audit and listed below, Mayo County Council is recommended to carry out the recommendations outlined in Section 4 of this report;

The audit process is a random sample On a particular day o[ a [acility's operation. Where al1 observation or recommendation against a particular issue has nol been reported, this should not be constrlled to mean that this issue is {ully addressed.

1. Source Protection

a. The Water Services Authority stated that it will make contact with the relevant personnel within Mayo County Council who liaises with the Western River Basin District team to obtain the most recent information on the catchment in an effort to characterise and identify any risks from potential sources of pollution into the catchment of the regional water supply

b, The Water Services AutllOrity informed the audit learn that landowncrs within 250 In of the intake point have been informed of their ob ligations under SI 610 01"2010 and protection measures are supervised by the treatment plant technician and caretakers. A survey is to be carried out between 250 m and 1000 m of the intake to determine if additional control measures are required.

2. Coagulation, Flocculation and Clarification

a. The Water Services Authority stated that 45% of the abstracted water receives full treatment; 55% of the water continues to bypass the clarification stage. is then mixed with the clarified water and passes through to IiIlration .

b. Perric sulphate is added at a dose of between I 10 mg/l and 130 mg/l and the dosing of ferric is gauged depending on the level of iron in the final water. The water is then dosed with po ly which varies fTom 0.13 toO.16 mg/l.

c . Jar tests were increased to hi-weekJy after the EPA's ;mdit iu 2008 but due to simHar results being obtained, they are now carried out only when variations in water quality occur which is 2~3 times per year. Jar test results are recorded on-site.

d. The Water Services Authority stated that floc carry·over has decreased with the increased cleaning of the settling tanks which is carried out on a bi·annual basis. The tanks were las! cleaned 6 weeks prior to the audit. Some pin-head Aoc was evident in the c larifiers on the day of the audit.

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3. Filtration

a. Backwash is automated based on time and occurs every 24-26 hours. Head loss or turbidity do not trigger backwash.

b. The Water Services Authority stated that turbidity levels on the filters post backwash can rise up to between 0.4 NTU and 0.6 NTU and further reductions in turbidity is not possible until the plant upgrade takes place. However levels of > 1.0 NTU were observed on the SCADA recording devise for Fi lters No. I and 3 (e.g. on 01 /09/ 11 and 18/09/11). The alarm on the SCADA is set at 2.0 NTU. The Water Services Authority stated that no follow-up action is taken to investigate the cause of turbidity peaks nor is any corrective action taken to prevent a reoccurrence.

c. A backwash on Filter No 3 was observed during the audit. The caretaker informed the audit team that the wall of Filter No 3 had eroded. This can lead to loss of filter media and a short-circuiting orthe filtrat ion process.

d. The turbidity level observed on the day of the audit once Filter No 3 was brought back into service post backwashing ranged from 0.57 NTU down to 0.3 NTU.

c. In an effort to reduce turbid ity'S post backwash the backwashing time was increased to 5.5 minutes (for the water backwash) since the last EPA audit and the filtration rate has decreased from 10.3 m'/m' /hr, but the rate rema ins above the design rate for the plant. It was stated that a slow start on the filters once they are brought back into service post backwashing can on ly be set up as part of the plant upgrade.

4. Chlorination and Disinfection

a. The disinfected water passes to two reservoirs with a vo lume of 10,000 m3 each. The Water Services Authority reported that there is 16 hours storage between the two reservoirs.

b. The set point for free ch lorine residua l at the plant is 0.8 mgll. The recorded residual chlorine in the plant reservoir was 1.04 mg/I Cl, on the day of the aud it.

5. Monitoring and Sampling Programme for treated water

a. Cryptosporidium monitoring is carried out weekly on the final water and results are held in Mayo County Council Offices in Castlebar. The Water Services Authority stated that the results were satisFactory. Cryplosporidium results were subm itted on 25"' May 20 11 to the EPA for 20 10 and up to May 20 11 and all results were negat ive fo r Cryptosporidium.

6. Exceedances of the Parametric Va lues

a. THMs persistently exceed the parametric value of 100 ug/I and the aud it team were informed during the audit of a recent THMs exceedance for the supply in September 201 1 which would be notified formally via emai l after the Audit.

7. Management and Control

a. The plant currently supplies 30,000 m'/day of treated water and therefore operates above its design capacity of 27,300 m'/day . The agreed action programme in response to the EPA' s Regulation 10(4) Direction issued to Mayo County Council on 21" Apr il 2009 planned for an upgrade to the Lough Mask treatment plant to provide a treatment capacity of40,600 m' /day. The projected comp letion date provided was 3 1" May 20 11 and this was the timeframe agreed in the Agency ' s approval lelter dated 24'h of Ju ly 2009.

b. The audit verified that the upgrade works have not yet commenced on-site and the plant remains to operate above its design capacity w ith 55% of the abstracted water continuing to by-pass thc coagulation, f1occulation and c larification treatment stage at the Lough Mask Drinking Water Treatment Plant. Only 45% of the abstracted water receives fu ll treatment.

c. Water conservation measures have been put in place which has reduced the rate of water consumption from 36,000 m'/day to 30,000 m'/day. The Water Service Authority stated that the proposed upgraded plant should provide 10,000 m'/day free capacity.

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3. Filtration

a. Backwash is automated based on time and occurs every 24-26 hours. 1·lead loss or turbidity do not trigger backwash.

b. The Water Services Authority stated that turbidity levels on the filters post backwash can rise up to between 0 .4 NTU and 0.6 NTU and further reductions in turbidity is not possible until the plant upgrade takes place. However levels of > 1.0 NTU were observed on the SCADA record ing devise for Filters No. I and 3 (e.g. on 01 /0911 1 and 18 /09/11). The alarm on the SCADA is set at 2.0 NTU . The Water Services A uthority stated that no follow-up act ion is taken to investigate the cause of turbidity peaks nor is any corrective action taken to prevent a reoccurrencc.

c. A backwash on Filter No 3 was observed during the audiL The caretaker informed the audjt team that the wall of Fi lter No 3 had croded. This can lead to loss of filter media and a short-c ircuiting of the filtration process.

d. The turbid ity level observed on the day of the audit once Filter No 3 was brought back into service post back washing ranged from 0.57 NTU down to 0.3 NTU.

e. In an effort to reduce turbidity's post backwash the backwashing time was increased to 5.5 minutes (for the water backwash) since the last EPA audit and the filtration rate has decreased from 10.3 mJ/m2/hr, but the rate remains above the design rate for the plant. 11 was stated that a s low start on the rillers once they are brought back into serv ice post backwashing can only be set up as part of the plant upgrade.

4. Chlorination and Disinfection

a. The disinfected water passes to two reservoirs with a vo lume of 10,000 m3 each. The Water Services Authority reported that there is 16 hours storage between the two reservoirs.

b. The set point for free ch lorine residua l at the plant is 0.8 mgll. The recorded residual chlorine in the p lant reservoir was 1.04 mg/I C l, on the day of the aud it.

5. Monitoring and Sampling Programme for treated water

a. Cryplolporiciillln monitoring is carried out weekly on the fi nal water and results fire held in Mayo County Council Offices in Castlebar. The Water Services Authority stated that the results were sat isfactory. c;,yplnsporidilllTl results were submitted on 25"' May 20 II to the EPA for 20 I 0 and up to May 20 11 and all results were negative fo r CryplosporidiulTI.

6. Exceedances of the Parametric Values

a. THMs pers istently exceed the parametric va lue of 100 ug/I and the audit team were informed dur ing the audit of a recent THMs exceedance for the supply in September 201 1 which would be notified formally via emai l afle r the Audit.

7. Management and Control a. The plant current ly supplies 30,000 m'/day of treated water and therefore operates above

its design capacity of 27,300 m' /day. The agreed action progrnmme in response to the EPA ' s Regt~ation 10(4) Direction issued to Mayo County Council on 2 1" April 2009 planned for an upgrade to the Lough Mask treatment plant to provide a treatment capacity of40,600 m'/day. The projected completion date provided was 3 1" May 2011 and this was the timefmme agreed in the Agency 's approval leUcr dated 24'" of Ju ly 2009.

b. The audit verified that the upgrade works have not yet cummenced on-site and the plant remains to operate above its design capacity with 55% of the abstracted water continuing to by-pass thc coagulation, flocculation and c larification treatment stage at the Lough Mask Drinking Water Treatment Plant. O nly 45% of the abstracted water receives fu ll treatment.

c. Water conservation measures have been put in place wh ich has reduced the rate of water consumption from 36.000 m'/day to 30,000 m'/day. The Waler Service Authority stated that the proposed upgraded plant should provide 10,000 m'/day free capacity.

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3. AUDITORS COMMENTS

The Agency audit found that 55% of the water abstracted does not receive full treatment at the Lough Mask Regional DWTP. This is an issue that was raised in the last audit on 4'h and 5'h of February 2008 and at this time the report stated that this matter needed to be addressed by Mayo County Council as a matter of priority. In add ition, Filter No 3 is in a state of disrepair and the information being recorded by turbidity monitors at the plant cannot be used to manage the treatment process to its optimum until such time as the upgrade is comp lete. Thus, the potential exists for Cryptosporidium, if present in the raw water, to break through the filters and enter the water supp ly. The Water Services Authority should ensure that each section of the treatment process is optimised pending the upgrade works that is planned to increase available capacity at the treatment works and cease the by-pass of water treatment processes . In the meantime the EPA should continue to be kept updated on the progress on achieving the much needed upgrade for the Lough Mask Water Treatment Plant.

4. RECOMMENDATIONS

Management and Control

a. The Water Services Authority shall takes measures to ensure priority is given to upgrading the existing water treatment plant as outlined in Mayo County Council' s Action Programme, which was agreed by the Agency on 24'h of July 2009 in response to the EPA' s Regulation 10(4) Direction issued to Mayo County Council on the 21 st of Apr il 2009.

Source Protection

a. The Water Serviccs Authority should identify all potentially po lluting discharges into the catchment with in 250 m and 1000 In from the abstraction point, as proposed, and sha ll implement mitigation measures where appropriate to reduce the potential impact of these discharges.

b. The Water Services Authority should liaise w ith the Western River Basin District (WIUlD) team responsible for implementing the Water Framework Directive to obtain an update on the risks from point and diffuse sources identified by the WRBD that could potentially impact ory the raw water abstraction point. The Water Services Authority shou ld implement mitigation measures, where appropriate, to reduce the potential impact of any discharges identified. .

Filtration

a. The Water Services Authority should rev iew the operation and condition of sand filter no. 3 and repair damage to its concrete side wall so as to ensure that any abnormal operating conditions are urgently rectified .

b. The Water Services Authority should use the information rrom the continuous turbidity monitors on the intake, after each fi lter and the final treated water at the water treatment plant to manage the treatment processes at the plant.

Exceedences of the Parametric Values

a. The Waler Services Authority shall follow tlle HSE's advice regarding the persistenl THMs exceedanees in the network i.e. " reduce chlorin.1tion if possible subject to not increasing the risk of nticrobiological failure" and "upgmde the treatment plant as soon as possible".

Monitoring and Sampling Programmes for Treated Water

a . The Water Services Authority shall submit on a quarterly basis (i) the week ly monitoring

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3. AUDITORS COMMENTS

The Agency audi t found that 55% of the water abstracted does not receive full treatment at the Lough Mask Regional DWTP. This is an issue that was raised in the last audit on 4'" and 5'" of February 2008 and at this time the report stated that this matter needed to be add ressed hy Mayo County Council as a matter of priority. lo addit ion, FilterNo 3 is in a state of disrepair and the information being recorded by turbidity monitors at the plant cannot be used to manage the treatment process to its optimum unt il such time as the upgrade is comp lete. Thus~ the potential exists for Cryptosporidium, if present in the raw water, to break through the filters and enter the water supply. The Water Services Authority ~hollld ensure that each section of the trealment process is optimised pend ing t.he upgrade works that is planned to increase avai lab le capacity at the trearment works and cease the by·pass of water treatment processes . In the meant ime the EPA shou ld continue to be kept updated on the progress on ach ieving the much needed upgrade for the Lough Mask Water Treatment Plant.

4. RECOMMENDATIONS

Management and Control

a.. The Water Services Authority shall takes measures to ensure priority is given to upgrading the existing water treatlllcnt plant as outlined in Mayo County Council's Action Programme, wh ich was agreed by the Agency on 24'" of July 2009 in response to U", EPA ' s Regulation 10(4) Direction issued to Mayo County Council on the 21 st of April 2009.

Source Protection

a. The Water Services Authority shou ld identify all potentially polluting discharges into lhe catchment within 250 m and 1000 m from the abstrac tion point, as proposed, and sha ll implement mitigation measures where appropriate to reduce the potential impact of these· discharges.

b. The Water Services Authority should liaise with the Western River Basin District (WH.Hl)) team respnnsible for implementing the Water Framework Directive to obtain an update on the risks from po in t and diffuse sources identified by the WRBD that could potentially impact 0 1)

the raw water abstraction point. The Water Services Authority should implement mitigation measures, where appropriate, to reduce the potential impact of any discharges identified.

Filtratio n

a. The Water Services Authority should review the operation and cond ition of sand filter no. 3 and repair damage to its concrete side wall so as to ensure that any abnormal operating conditions are urgently rectified.

b. The Water Services AutllOrity should use the information from the continuous turbidity monitors on the intake, after each fi lter and the fi nal treated water at the W;:Iler treatment plant to manage the treatment processes at the plant.

Exceedences of the Parametric Values

a , The Water Services Authority shall follow U,e HSE·s advice regarding tI", persistent lliMs exccedances in the ne twork i.e. ··reduce chlorination if possible subject to not increasing the risk of microbiological failure" a nd "up!,'mde the treamlent plant as soon as possibl .. ·.

·Monitoring and Sampling Programmes for Treated Water

a . The Water Services Authority shall submit on a quarterly basis ( i) the weekly monitoring

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results for Cryptosporidium sampled from the treated water, (i i) the THM s exceedanees ari sing fro m compliance monitoring taken in the network and (iii) an update on the upgrade of the Lough Mask Water Treatment Plant. Each report shall be submitted to the EPA by 3 1" December. 3 1 SI March and 30th June, until such time as the upgrade is complete.

FOLLOW-UP A CTIO NS REQ UIRED BY TH E LOCA L AUT HORITY

The Water Services Author ity should submit a report to the Agency within one month of the date of issue of this aud it report detail ing how it has dealt with the issues of concern identified during this audit. The report should include de tails on the action taken and planned to address the various recommendations, including timeframe for commencement and completion or any planned work.

The EPA advises that the fi ndings and recommendations from this audit report should. where relevant, be addressed at a ll other treatment plants operated and managed by Mayo County Counc il.

The EPA a lso advices that it is considering taking fu rther enforcement action in light of the breaches of the Regulation 10(4) Direction issued to Mayo County Counc il on the 21st o f April 2009.

Please quote the File Reference Number in any future correspondence in relation to this Report.

Report prepared by:

Date:

Derva I Devaney

Inspector

Reviewed by:

Date:

Leo Sweeney

M anager, Environmenta l Enforcement

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results for Cryptospuridilllll sampled from the treated water, (ii) the. THMs exceedances ari sing from comp liance monitoring t(lkeo in the network and (iii) an update on the upgrade of the Lough Mask Water T reatment Plant. Each repurt shall be submitted to the EPA by 31" December. 31 31 March and 30dl June, until such time as the upgrade is complete.

FOLLOW-UP ACTIONS REQ UI RED BY THE LOCAL AUTHORITY

The Water Services Author ity should subm it a report to the Agency within one month of the date of issue of this audit report detail ing how it has dea lL with the issues of concern identified during this aud it. The report should include details on the action taken and planned to address the various recommendations, including timeframe for commencement and completion of any planned work.

The EPA advises that the fi ndings and recommendations from this audit report should, where relevant, be addressed at all other treatment plants operated and managed by Mayo County Council.

The EPA also advices that it is cons idering taking further enforcement action in light of the breaches of the Regu lation 10(4) Direction issued to Mayo County Co uncil on the 21st of April 2009.

Please quote the File Reference Number in any future correspondence in relation to this Report

Report prepared by:

Date:

Derval Devaney

Inspector

Reviewed by:

Date:

Leo Sweeney

Manager, Environmental Enforcement

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