WaterCheck Ireland

Cork Tap Water Quality

EPA monitoring records for Water Supply Zones mapped to Cork contain 6,471 monitoring results across 71 parameters in 2025.

The separate EPA exceedance dataset contains 28 listed exceedance records across 8 parameters.

The most frequently listed were Colony Count @ 22°C (7), Coliform Bacteria (6) and Colour (5).

These are historical monitoring records and do not confirm the current status of water at a specific address. Current notices are maintained by Uisce Éireann.

Latest monitoring year
2025
Page updated
September 2026
Water Supply Zones
5
6,471Monitoring results
71Parameters tested
28EPA-listed exceedances
371Samples

Monitoring results apply to the Water Supply Zones as a whole and may include sampling locations outside Cork.

Selected monitoring data

Key drinking water parameters

Parameters are shown when measurements are available. Text-only and censored values remain unchanged in the detailed history.

Lead

2025 median4 ug/l
2025 maximum7 ug/l
Measurements in 202528

0 EPA-listed exceedances in 2025.

View parameter history

Individual numeric measurements from 2021–2025. Text-only and censored results are retained in the history JSON and are not plotted as numbers.

Open this chart to load the measurements.

Numeric resultEPA-listed exceedance

12 numeric measurements available; 102 text-only records retained in JSON.

Nitrate

2025 median12.04
2025 maximum34.71
Measurements in 202528

0 EPA-listed exceedances in 2025.

View parameter history

Individual numeric measurements from 2021–2025. Text-only and censored results are retained in the history JSON and are not plotted as numbers.

Open this chart to load the measurements.

Numeric resultEPA-listed exceedance

92 numeric measurements available; 22 text-only records retained in JSON.

E. coli

2025 median0 100ml
2025 maximum0 100ml
Measurements in 2025336

0 EPA-listed exceedances in 2025.

View parameter history

Individual numeric measurements from 2021–2025. Text-only and censored results are retained in the history JSON and are not plotted as numbers.

Open this chart to load the measurements.

Numeric resultEPA-listed exceedance

1,186 numeric measurements available; 180 text-only records retained in JSON.

Coliform Bacteria

2025 median0 100ml
2025 maximum24 100ml
Measurements in 2025336

6 EPA-listed exceedances in 2025.

View parameter history

Individual numeric measurements from 2021–2025. Text-only and censored results are retained in the history JSON and are not plotted as numbers.

Open this chart to load the measurements.

Numeric resultEPA-listed exceedance

1,193 numeric measurements available; 173 text-only records retained in JSON.

Fluoride

2025 median0.7 mg/l
2025 maximum0.9 mg/l
Measurements in 202528

0 EPA-listed exceedances in 2025.

View parameter history

Individual numeric measurements from 2021–2025. Text-only and censored results are retained in the history JSON and are not plotted as numbers.

Open this chart to load the measurements.

Numeric resultEPA-listed exceedance

113 numeric measurements available; 1 text-only records retained in JSON.

Iron

2025 median29 ug/l
2025 maximum223 ug/l
Measurements in 2025336

1 EPA-listed exceedances in 2025.

View parameter history

Individual numeric measurements from 2021–2025. Text-only and censored results are retained in the history JSON and are not plotted as numbers.

Open this chart to load the measurements.

Numeric resultEPA-listed exceedance

443 numeric measurements available; 922 text-only records retained in JSON.

Arsenic

2025 median—
2025 maximum—
Measurements in 202528

0 EPA-listed exceedances in 2025.

View parameter history

Individual numeric measurements from 2021–2025. Text-only and censored results are retained in the history JSON and are not plotted as numbers.

Open this chart to load the measurements.

Numeric resultEPA-listed exceedance

0 numeric measurements available; 114 text-only records retained in JSON.

20256,471 results · 28 listed exceedances
Total results — independent scale
0 3,235.5 6,471 4,982 2021 4,429 2022 4,547 2023 4,318 2024 6,471 2025
Listed exceedances per 1,000 results — independent scale
0.000 3.500 6.999 3.613 2021 6.999 2022 5.278 2023 3.242 2024 4.327 2025

This is our descriptive frequency: listed exceedance records divided by result records, multiplied by 1,000. It is not an official EPA compliance rate. Differences in sampling volume and parameters tested affect comparisons. A missing denominator is shown as unavailable.

Monitoring history by year
YearResultsSamplesParametersListed exceedancesPer 1,000 results
20214,98233466183.613
20224,42929666316.999
20234,54730067245.278
20244,31826968143.242
20256,47137171284.327

Year-to-year detail

2025 compared with 2024

Changes describe dataset volumes only. The comparison uses the previous available year.

Results
20244,318
20256,471
+2,153
Listed exceedances
202414
202528
+14
Samples
2024269
2025371
+102
Parameters
202468
202571
+3

Parameters with EPA-listed exceedances

Values and limits are reproduced as reported. Different unit/limit pairs are shown separately.

Colony Count @ 22°C

7 listed exceedance records / 308 tests2.27%

Descriptive frequency of records, not an official compliance measure.

Highest listed result
300 1ml
Reported limit
100 1ml
Records with this unit/limit pair
7
Latest exceedance
02 Dec 2025

Coliform Bacteria

6 listed exceedance records / 336 tests1.79%

Descriptive frequency of records, not an official compliance measure.

Highest listed result
24 100ml
Reported limit
0 100ml
Records with this unit/limit pair
6
Latest exceedance
04 Nov 2025

Colour

5 listed exceedance records / 336 tests1.49%

Descriptive frequency of records, not an official compliance measure.

Highest listed result
32 Hazen
Reported limit
20 Hazen
Records with this unit/limit pair
5
Latest exceedance
18 Nov 2025

Manganese

5 listed exceedance records / 146 tests3.42%

Descriptive frequency of records, not an official compliance measure.

Highest listed result
127 ug/l
Reported limit
50 ug/l
Records with this unit/limit pair
5
Latest exceedance
18 Nov 2025

Turbidity (at tap)

2 listed exceedance records / 336 tests0.60%

Descriptive frequency of records, not an official compliance measure.

Highest listed result
5.95 NTU
Reported limit
4 NTU
Records with this unit/limit pair
2
Latest exceedance
18 Nov 2025

Bisphenol A

1 listed exceedance records / 28 tests3.57%

Descriptive frequency of records, not an official compliance measure.

Highest listed result
9.23 µg/l
Reported limit
2.5 µg/l
Records with this unit/limit pair
1
Latest exceedance
15 Jul 2025

Iron

1 listed exceedance records / 336 tests0.30%

Descriptive frequency of records, not an official compliance measure.

Highest listed result
223 ug/l
Reported limit
200 ug/l
Records with this unit/limit pair
1
Latest exceedance
06 May 2025

Trihalomethanes(Total)

1 listed exceedance records / 28 tests3.57%

Descriptive frequency of records, not an official compliance measure.

Highest listed result
144 ug/l
Reported limit
100 ug/l
Records with this unit/limit pair
1
Latest exceedance
19 Aug 2025

Across the year

When were listed exceedances recorded?

Each point represents one listed exceedance record. Records on the same date remain separate.

Colony Count @ 22°C02 Dec 2025
300 1mlReported result
100 1mlReported limit
GlashaboyWater supply
JanFebMarAprMayJunJulAugSepOctNovDecBisphenol AColiform BacteriaColony Count @ 22°CColourIronManganeseTrihalomethanes(Total)Turbidity (at tap)02 Dec 2025 — Colony Count @ 22°C: 300 1ml; reported limit 100; Glashaboy; sample 2025/058619 Nov 2025 — Colony Count @ 22°C: 190 1ml; reported limit 100; Cork Harbour & City; sample 2025/210218 Nov 2025 — Colour: 23 Hazen; reported limit 20; Cork City Water Supply; sample 21131018 Nov 2025 — Manganese: 82 ug/l; reported limit 50; Cork City Water Supply; sample 21131018 Nov 2025 — Turbidity (at tap): 4.94 NTU; reported limit 4; Cork City Water Supply; sample 21130818 Nov 2025 — Turbidity (at tap): 5.95 NTU; reported limit 4; Cork City Water Supply; sample 21131204 Nov 2025 — Coliform Bacteria: 24 100ml; reported limit 0; Cork City Water Supply; sample 20919704 Nov 2025 — Manganese: 51 ug/l; reported limit 50; Cork City Water Supply; sample 20919628 Oct 2025 — Colony Count @ 22°C: 300 1ml; reported limit 100; Glashaboy; sample 2025/123621 Oct 2025 — Coliform Bacteria: 8 100ml; reported limit 0; Cork City Water Supply; sample 20641621 Oct 2025 — Manganese: 127 ug/l; reported limit 50; Cork City Water Supply; sample 20641514 Oct 2025 — Colony Count @ 22°C: 144 1ml; reported limit 100; Cork City Water Supply; sample 20511807 Oct 2025 — Coliform Bacteria: 14 100ml; reported limit 0; Cork City Water Supply; sample 20339722 Sep 2025 — Colour: 25 Hazen; reported limit 20; Cork Harbour & City; sample 2025/140409 Sep 2025 — Coliform Bacteria: 2 100ml; reported limit 0; Cork City Water Supply; sample 19807904 Sep 2025 — Colony Count @ 22°C: 300 1ml; reported limit 100; Cork Harbour & City; sample 19723019 Aug 2025 — Coliform Bacteria: 2 100ml; reported limit 0; Cork Harbour & City; sample 2025/118619 Aug 2025 — Colour: 24 Hazen; reported limit 20; Cork Harbour & City; sample 19437219 Aug 2025 — Trihalomethanes(Total): 144 ug/l; reported limit 100; Cork Harbour & City; sample 2025/119515 Jul 2025 — Bisphenol A: 9.23 µg/l; reported limit 2.5; Cork Harbour & City; sample 2025/117610 Jun 2025 — Manganese: 58 ug/l; reported limit 50; Cork City Water Supply; sample 18134406 May 2025 — Iron: 223 ug/l; reported limit 200; Cork Harbour & City; sample 17529306 May 2025 — Manganese: 53 ug/l; reported limit 50; Cork Harbour & City; sample 17529319 Mar 2025 — Coliform Bacteria: 5 100ml; reported limit 0; Cork Harbour & City; sample 2025/045919 Mar 2025 — Colony Count @ 22°C: 151 1ml; reported limit 100; Cork Harbour & City; sample 2025/045911 Feb 2025 — Colony Count @ 22°C: 175 1ml; reported limit 100; Cork City Water Supply; sample 202502321 Jan 2025 — Colour: 32 Hazen; reported limit 20; Cork City Water Supply; sample 202500821 Jan 2025 — Colour: 28 Hazen; reported limit 20; Cork Harbour & City; sample 2025010

28 listed exceedance records across 8 parameters in 2025.

Your mapped supply

Water supply

Every Water Supply Zone used for this page's headline figures is included. Geographic overlaps are reported separately and are not added together or weighted by population.

Cork Harbour and City

33.04% geographic overlap with the Cork Built Up Area.

Technical mapping details
EDEN code
0500PUB3401
Local authority
Cork
Page totals
Included
Spatial rank
1
Historical EPA scheme
Available
Latest monitoring year
2025
Cork City Water Supply

15.67% geographic overlap with the Cork Built Up Area.

Technical mapping details
EDEN code
0400PUB1001
Local authority
Cork City
Page totals
Included
Spatial rank
2
Historical EPA scheme
Available
Latest monitoring year
2025
Glashaboy

6.34% geographic overlap with the Cork Built Up Area.

Technical mapping details
EDEN code
0500PUB3303
Local authority
Cork
Page totals
Included
Spatial rank
3
Historical EPA scheme
Available
Latest monitoring year
2025
Tibbotstown

1.75% geographic overlap with the Cork Built Up Area.

Technical mapping details
EDEN code
0500PUB2408
Local authority
Cork
Page totals
Included
Spatial rank
4
Historical EPA scheme
Available
Latest monitoring year
2025
Glanmire

1.25% geographic overlap with the Cork Built Up Area.

Technical mapping details
EDEN code
0500PUB2107
Local authority
Cork
Page totals
Included
Spatial rank
5
Historical EPA scheme
Available
Latest monitoring year
2025

Detailed data

The complete parameter and listed exceedance tables for the reporting year.

71 parameter rows28 listed exceedance records371 samples
Show detailed data71 parameters · 28 exceedance records

Complete parameter index

All parameters in 2025

All parameters with test results or listed exceedance records in the latest reporting year
1,2-dichloroethane28016 Dec 20255
2,3,6-trichlorobenzoic acid28016 Dec 20255
2,4-D28016 Dec 20255
Acrylamide28016 Dec 20255
Aluminium336016 Dec 20255
Ammonium28016 Dec 20255
Antimony28016 Dec 20255
Arsenic28016 Dec 20255
Atrazine28016 Dec 20255
Bentazone28016 Dec 20255
Benzene28016 Dec 20255
Benzo(a)pyrene28016 Dec 20255
Bisphenol A28116 Dec 20255
Boron28016 Dec 20255
Bromate28016 Dec 20255
Cadmium28016 Dec 20255
Chlorfenvinphos28016 Dec 20255
Chloride67016 Dec 20255
Chromium28016 Dec 20255
Clopyralid28016 Dec 20255
Clostridium Perfringens28016 Dec 20255
Coliform Bacteria336616 Dec 20255
Colony Count @ 22°C308716 Dec 20255
Colour336516 Dec 20255
Conductivity336016 Dec 20255
Copper28016 Dec 20255
Cryptosporidium29016 Dec 20254
Cyanide28016 Dec 20255
Cypermethrin28016 Dec 20255
Dichlobenil28016 Dec 20255
Dichlorprop28016 Dec 20255
Diflufenican28016 Dec 20255
Diuron28016 Dec 20255
E. coli336016 Dec 20255
Enterococci336016 Dec 20255
Fluoride28016 Dec 20255
Free Chlorine342016 Dec 20255
Giardia29016 Dec 20254
Glyphosate28016 Dec 20255
Haloacetic acids (Sum of 5 HAAs)28016 Dec 20255
Iron336116 Dec 20255
Isoproturon28016 Dec 20255
Lead28016 Dec 20255
Linuron28016 Dec 20255
Manganese146516 Dec 20255
MCPA28016 Dec 20255
Mecoprop28016 Dec 20255
Mercury28016 Dec 20255
Metaldehyde28016 Dec 20255
Microcystin-LR12023 Sep 20253
Nickel28016 Dec 20255
Nitrate28016 Dec 20255
Nitrite (at tap)28016 Dec 20255
Odour339016 Dec 20255
PAH28016 Dec 20255
Pendimethalin28016 Dec 20255
Pesticides - Total28016 Dec 20255
pH336016 Dec 20255
Propyzamide28016 Dec 20255
Selenium28016 Dec 20255
Simazine28016 Dec 20255
Sodium28016 Dec 20255
Sulphate62016 Dec 20255
Sum of PFAS (sum of 20)28016 Dec 20255
Taste339016 Dec 20255
Tetrachloroethene & Trichloroethene28016 Dec 20255
Total Chlorine342016 Dec 20255
Total Organic Carbon32016 Dec 20255
Triclopyr28016 Dec 20255
Trihalomethanes(Total)28116 Dec 20255
Turbidity (at tap)336216 Dec 20255

Showing 71 of 71 parameters.

EPA exceedance dataset

Listed exceedances in 2025

Newest first. Sample IDs distinguish records that may otherwise look identical.

All listed exceedance records in the latest reporting year
DateParameterResultUnitReported limitWater supply / EDENSample ID
02 Dec 2025Colony Count @ 22°C3001ml100Glashaboy
0500PUB3303		2025/0586
19 Nov 2025Colony Count @ 22°C1901ml100Cork Harbour & City
0500PUB3401		2025/2102
18 Nov 2025Colour23Hazen20Cork City Water Supply
0400PUB1001		211310
18 Nov 2025Manganese82ug/l50Cork City Water Supply
0400PUB1001		211310
18 Nov 2025Turbidity (at tap)4.94NTU4Cork City Water Supply
0400PUB1001		211308
18 Nov 2025Turbidity (at tap)5.95NTU4Cork City Water Supply
0400PUB1001		211312
04 Nov 2025Coliform Bacteria24100ml0Cork City Water Supply
0400PUB1001		209197
04 Nov 2025Manganese51ug/l50Cork City Water Supply
0400PUB1001		209196
28 Oct 2025Colony Count @ 22°C3001ml100Glashaboy
0500PUB3303		2025/1236
21 Oct 2025Coliform Bacteria8100ml0Cork City Water Supply
0400PUB1001		206416
21 Oct 2025Manganese127ug/l50Cork City Water Supply
0400PUB1001		206415
14 Oct 2025Colony Count @ 22°C1441ml100Cork City Water Supply
0400PUB1001		205118
07 Oct 2025Coliform Bacteria14100ml0Cork City Water Supply
0400PUB1001		203397
22 Sep 2025Colour25Hazen20Cork Harbour & City
0500PUB3401		2025/1404
09 Sep 2025Coliform Bacteria2100ml0Cork City Water Supply
0400PUB1001		198079
04 Sep 2025Colony Count @ 22°C3001ml100Cork Harbour & City
0500PUB3401		197230
19 Aug 2025Coliform Bacteria2100ml0Cork Harbour & City
0500PUB3401		2025/1186
19 Aug 2025Colour24Hazen20Cork Harbour & City
0500PUB3401		194372
19 Aug 2025Trihalomethanes(Total)144ug/l100Cork Harbour & City
0500PUB3401		2025/1195
15 Jul 2025Bisphenol A9.23µg/l2.5Cork Harbour & City
0500PUB3401		2025/1176
10 Jun 2025Manganese58ug/l50Cork City Water Supply
0400PUB1001		181344
06 May 2025Iron223ug/l200Cork Harbour & City
0500PUB3401		175293
06 May 2025Manganese53ug/l50Cork Harbour & City
0500PUB3401		175293
19 Mar 2025Coliform Bacteria5100ml0Cork Harbour & City
0500PUB3401		2025/0459
19 Mar 2025Colony Count @ 22°C1511ml100Cork Harbour & City
0500PUB3401		2025/0459
11 Feb 2025Colony Count @ 22°C1751ml100Cork City Water Supply
0400PUB1001		2025023
21 Jan 2025Colour32Hazen20Cork City Water Supply
0400PUB1001		2025008
21 Jan 2025Colour28Hazen20Cork Harbour & City
0500PUB3401		2025010

Common questions

Frequently asked questions

Is Cork tap water safe to drink?

WaterCheck Ireland does not issue a current safe or unsafe verdict. This page presents historical monitoring data. Check Uisce Éireann for any current Boil Water or Do Not Consume notices affecting your address.

Can you drink tap water in Cork?

WaterCheck Ireland provides historical drinking-water monitoring data, not a current safe or unsafe verdict. For current Boil Water or Do Not Consume notices, check your Eircode with Uisce Éireann.

What is the tap water quality in Cork?

In 2025, monitoring data for 5 Water Supply Zones mapped to Cork included 6,471 results across 71 parameters. The separate EPA-listed exceedance dataset contains 28 records for those zones in 2025. These figures summarise historical records and are not a current safety verdict.

Who monitors drinking water quality in Cork?

The historical monitoring figures shown here come from drinking-water datasets published by the Environmental Protection Agency (EPA), Ireland. Uisce Éireann operates public water supplies and publishes current supply notices.

What is a Water Supply Zone?

A Water Supply Zone is a defined area supplied by a public drinking-water system. Monitoring records apply to the zone as a whole, so sampling locations can be outside the Census Built Up Area.

What does a listed exceedance mean?

It is a record published in the separate EPA exceedance dataset. WaterCheck Ireland reproduces those records and does not infer additional exceedances or turn the record count into a safety assessment.

How can I check current water notices for my Eircode?

Use your Eircode on the Uisce Éireann website to check current Boil Water and Do Not Consume notices. This page is based on historical monitoring data and is not a live notice service.

Explore nearby reports

Water Quality Near Cork

Nearest published Built Up Areas, ordered by straight-line distance between Census reference points.

Passage West and MonkstownCork · approximately 8.6 kmCarrigalineCork · approximately 10.0 kmCobhCork · approximately 11.5 kmCarrigtwohillCork · approximately 12.9 kmMidletonCork · approximately 19.2 kmKinsaleCork · approximately 21.8 km

Connected by mapped supply

Places sharing this Water Supply Zone

These published places share at least one Water Supply Zone used in this page's headline figures.

Passage West and MonkstownCork Harbour and CityCarrigalineCork Harbour and CityCobhGlashaboyCarrigtwohillTibbotstown, GlashaboyMidletonTibbotstown

How this page is made

Sources and methodology

Settlement
Census 2022 Built Up Area: Cork city and suburbs. Population refers to the whole Built Up Area.
Supply mapping
Uisce Éireann Water Supply Zone boundaries are matched geographically to the settlement.
Monitoring
EPA monitoring results and the separate listed exceedance dataset, 2021–2025.
Interpretation
Geographic overlap measures land area, not population served; monitoring applies across the full supply zone.

Read the full methodologyView data sources