WaterCheck Ireland

Cobh Tap Water Quality

EPA monitoring records for Water Supply Zones mapped to Cobh contain 750 monitoring results across 70 parameters in 2025.

The separate EPA exceedance dataset contains 2 listed exceedance records across 1 parameter.

The most frequently listed parameter was Colony Count @ 22°C (2).

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 Zone
Glashaboy
Geographic overlap
90.98%
750Monitoring results
70Parameters tested
2EPA-listed exceedances
50Samples

The Cobh Built Up Area overlaps Glashaboy across approximately 90.98% of its land area.

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

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 median— ug/l
2025 maximum— ug/l
Measurements in 20254

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.

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Numeric resultEPA-listed exceedance

3 numeric measurements available; 13 text-only records retained in JSON.

Nitrate

2025 median25.6
2025 maximum25.9
Measurements in 20254

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.

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Numeric resultEPA-listed exceedance

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

E. coli

2025 median0
2025 maximum0
Measurements in 202536

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.

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Numeric resultEPA-listed exceedance

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

Coliform Bacteria

2025 median0
2025 maximum0
Measurements in 202536

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.

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Numeric resultEPA-listed exceedance

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

Fluoride

2025 median0.7
2025 maximum0.8
Measurements in 20254

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.

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Numeric resultEPA-listed exceedance

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

Iron

2025 median30 ug/l
2025 maximum30 ug/l
Measurements in 202536

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

9 numeric measurements available; 147 text-only records retained in JSON.

Arsenic

2025 median—
2025 maximum—
Measurements in 20254

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; 16 text-only records retained in JSON.

2025750 results · 2 listed exceedances
Total results — independent scale
0 375 750 584 2021 547 2022 603 2023 554 2024 750 2025
Listed exceedances per 1,000 results — independent scale
0.000 2.742 5.484 1.712 2021 5.484 2022 3.317 2023 1.805 2024 2.667 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
2021584446611.712
2022547416635.484
2023603476723.317
2024554316711.805
2025750507022.667

Year-to-year detail

2025 compared with 2024

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

Results
2024554
2025750
+196
Listed exceedances
20241
20252
+1
Samples
202431
202550
+19
Parameters
202467
202570
+3

Parameters with EPA-listed exceedances

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

Colony Count @ 22°C

2 listed exceedance records / 32 tests6.25%

Descriptive frequency of records, not an official compliance measure.

Highest listed result
300 1ml
Reported limit
100 1ml
Records with this unit/limit pair
2
Latest exceedance
02 Dec 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
JanFebMarAprMayJunJulAugSepOctNovDecColony Count @ 22°C02 Dec 2025 — Colony Count @ 22°C: 300 1ml; reported limit 100; Glashaboy; sample 2025/058628 Oct 2025 — Colony Count @ 22°C: 300 1ml; reported limit 100; Glashaboy; sample 2025/1236

2 listed exceedance records across 1 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.

Glashaboy

90.98% geographic overlap with the Cobh Built Up Area.

Technical mapping details
EDEN code
0500PUB3303
Local authority
Cork
Page totals
Included
Spatial rank
1
Historical EPA scheme
Available
Latest monitoring year
2025

Detailed data

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

70 parameter rows2 listed exceedance records50 samples
Show detailed data70 parameters · 2 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-dichloroethane4023 Sep 20251
2,3,6-trichlorobenzoic acid4023 Sep 20251
2,4-D4023 Sep 20251
Acrylamide4023 Sep 20251
Aluminium36002 Dec 20251
Ammonium4023 Sep 20251
Antimony4023 Sep 20251
Arsenic4023 Sep 20251
Atrazine4023 Sep 20251
Bentazone4023 Sep 20251
Benzene4023 Sep 20251
Benzo(a)pyrene4023 Sep 20251
Bisphenol A4023 Sep 20251
Boron4023 Sep 20251
Bromate4023 Sep 20251
Cadmium4023 Sep 20251
Chlorfenvinphos4023 Sep 20251
Chloride4023 Sep 20251
Chromium4023 Sep 20251
Clopyralid4023 Sep 20251
Clostridium Perfringens4023 Sep 20251
Coliform Bacteria36002 Dec 20251
Colony Count @ 22°C32202 Dec 20251
Colour36002 Dec 20251
Conductivity36002 Dec 20251
Copper4023 Sep 20251
Cryptosporidium11016 Dec 20251
Cyanide4023 Sep 20251
Cypermethrin4023 Sep 20251
Dichlobenil4023 Sep 20251
Dichlorprop4023 Sep 20251
Diflufenican4023 Sep 20251
Diuron4023 Sep 20251
E. coli36002 Dec 20251
Enterococci36002 Dec 20251
Fluoride4023 Sep 20251
Free Chlorine39002 Dec 20251
Giardia11016 Dec 20251
Glyphosate4023 Sep 20251
Haloacetic acids (Sum of 5 HAAs)4023 Sep 20251
Iron36002 Dec 20251
Isoproturon4023 Sep 20251
Lead4023 Sep 20251
Linuron4023 Sep 20251
Manganese4023 Sep 20251
MCPA4023 Sep 20251
Mecoprop4023 Sep 20251
Mercury4023 Sep 20251
Metaldehyde4023 Sep 20251
Nickel4023 Sep 20251
Nitrate4023 Sep 20251
Nitrite (at tap)4023 Sep 20251
Odour39002 Dec 20251
PAH4023 Sep 20251
Pendimethalin4023 Sep 20251
Pesticides - Total4023 Sep 20251
pH36002 Dec 20251
Propyzamide4023 Sep 20251
Selenium4023 Sep 20251
Simazine4023 Sep 20251
Sodium4023 Sep 20251
Sulphate4023 Sep 20251
Sum of PFAS (sum of 20)4023 Sep 20251
Taste39002 Dec 20251
Tetrachloroethene & Trichloroethene4023 Sep 20251
Total Chlorine39002 Dec 20251
Total Organic Carbon4023 Sep 20251
Triclopyr4023 Sep 20251
Trihalomethanes(Total)4023 Sep 20251
Turbidity (at tap)36002 Dec 20251

Showing 70 of 70 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
28 Oct 2025Colony Count @ 22°C3001ml100Glashaboy
0500PUB3303		2025/1236

Common questions

Frequently asked questions

Is Cobh 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 Cobh?

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 Cobh?

In 2025, monitoring data for the Water Supply Zone mapped to Cobh included 750 results across 70 parameters. The separate EPA-listed exceedance dataset contains 2 records for those zones in 2025. These figures summarise historical records and are not a current safety verdict.

Who monitors drinking water quality in Cobh?

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 Cobh

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

Passage West and MonkstownCork · approximately 2.9 kmCarrigtwohillCork · approximately 6.8 kmCarrigalineCork · approximately 7.6 kmMidletonCork · approximately 10.9 kmCorkCork · approximately 11.5 kmKinsaleCork · approximately 22.4 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.

CarrigtwohillGlashaboyCorkGlashaboy

How this page is made

Sources and methodology

Settlement
Census 2022 Built Up Area: Cobh. 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