WaterCheck Ireland

Westport Tap Water Quality

EPA monitoring records for Water Supply Zones mapped to Westport contain 1,945 monitoring results across 71 parameters in 2025.

The separate EPA exceedance dataset contains 4 listed exceedance records across 3 parameters.

The most frequently listed were Colour (2), Coliform Bacteria (1) and E. coli (1).

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
3
1,945Monitoring results
71Parameters tested
4EPA-listed exceedances
94Samples

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

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 median1
2025 maximum2
Measurements in 202513

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

4 numeric measurements available; 48 text-only records retained in JSON.

Nitrate

2025 median2.07
2025 maximum3.01
Measurements in 202513

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

37 numeric measurements available; 11 text-only records retained in JSON.

E. coli

2025 median0 100ml
2025 maximum1 100ml
Measurements in 202592

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

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

Coliform Bacteria

2025 median0 100ml
2025 maximum1 100ml
Measurements in 202592

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

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

Fluoride

2025 median0.7
2025 maximum0.8
Measurements in 202513

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

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

Iron

2025 median37 ug/l
2025 maximum129 ug/l
Measurements in 202592

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

332 numeric measurements available; 48 text-only records retained in JSON.

Arsenic

2025 median2
2025 maximum3
Measurements in 202513

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; 43 text-only records retained in JSON.

20251,945 results · 4 listed exceedances
Total results — independent scale
0 972.5 1,945 1,355 2021 1,496 2022 1,492 2023 1,476 2024 1,945 2025
Listed exceedances per 1,000 results — independent scale
0.000 4.021 8.043 1.476 2021 1.337 2022 8.043 2023 1.355 2024 2.057 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
20211,355876521.476
20221,496906521.337
20231,4928667128.043
20241,476906721.355
20251,945947142.057

Year-to-year detail

2025 compared with 2024

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

Results
20241,476
20251,945
+469
Listed exceedances
20242
20254
+2
Samples
202490
202594
+4
Parameters
202467
202571
+4

Parameters with EPA-listed exceedances

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

Colour

2 listed exceedance records / 92 tests2.17%

Descriptive frequency of records, not an official compliance measure.

Highest listed result
27 Hazen
Reported limit
20 Hazen
Records with this unit/limit pair
2
Latest exceedance
01 Aug 2025

Coliform Bacteria

1 listed exceedance records / 92 tests1.09%

Descriptive frequency of records, not an official compliance measure.

Highest listed result
1 100ml
Reported limit
0 100ml
Records with this unit/limit pair
1
Latest exceedance
31 Jul 2025

E. coli

1 listed exceedance records / 92 tests1.09%

Descriptive frequency of records, not an official compliance measure.

Highest listed result
1 100ml
Reported limit
0 100ml
Records with this unit/limit pair
1
Latest exceedance
31 Jul 2025

Across the year

When were listed exceedances recorded?

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

Colour01 Aug 2025
21 HazenReported result
20 HazenReported limit
LOUGH MASK RWSSWater supply
JanFebMarAprMayJunJulAugSepOctNovDecColiform BacteriaColourE. coli01 Aug 2025 — Colour: 21 Hazen; reported limit 20; LOUGH MASK RWSS; sample 19122131 Jul 2025 — Coliform Bacteria: 1 100ml; reported limit 0; LOUGH MASK RWSS; sample 19096231 Jul 2025 — E. coli: 1 100ml; reported limit 0; LOUGH MASK RWSS; sample 19096213 Jun 2025 — Colour: 27 Hazen; reported limit 20; LOUGH MASK RWSS; sample 181875

4 listed exceedance records across 3 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.

Lough Mask Westport Town Mixed Supply

56.91% geographic overlap with the Westport Built Up Area.

Technical mapping details
EDEN code
2200PUB1039
Local authority
Mayo
Page totals
Included
Spatial rank
1
Historical EPA scheme
Available
Latest monitoring year
2025
Lough Mask RWSS

10.91% geographic overlap with the Westport Built Up Area.

Technical mapping details
EDEN code
2200PUB1032
Local authority
Mayo
Page totals
Included
Spatial rank
2
Historical EPA scheme
Available
Latest monitoring year
2025
WESTPORT PWS

4.71% geographic overlap with the Westport Built Up Area.

Technical mapping details
EDEN code
2200PUB1025
Local authority
Mayo
Page totals
Included
Spatial rank
3
Historical EPA scheme
Available
Latest monitoring year
2025

Detailed data

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

71 parameter rows4 listed exceedance records94 samples
Show detailed data71 parameters · 4 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-dichloroethane13018 Nov 20253
2,3,6-trichlorobenzoic acid13018 Nov 20253
2,4-D13018 Nov 20253
Acrylamide13018 Nov 20253
Aluminium79019 Dec 20253
Ammonium13018 Nov 20253
Antimony13018 Nov 20253
Arsenic13018 Nov 20253
Atrazine13018 Nov 20253
Bentazone13018 Nov 20253
Benzene13018 Nov 20253
Benzo(a)pyrene13018 Nov 20253
Bisphenol A10018 Nov 20253
Boron13018 Nov 20253
Bromate13018 Nov 20253
Cadmium13018 Nov 20253
Chlorfenvinphos13018 Nov 20253
Chloride13018 Nov 20253
Chromium13018 Nov 20253
Clopyralid13018 Nov 20253
Clostridium Perfringens13018 Nov 20253
Coliform Bacteria92119 Dec 20253
Colony Count @ 22°C79019 Dec 20253
Colour92219 Dec 20253
Conductivity92019 Dec 20253
Copper13018 Nov 20253
Cryptosporidium2012 Feb 20251
Cyanide13018 Nov 20253
Cypermethrin13018 Nov 20253
Dichlobenil13018 Nov 20253
Dichlorprop13018 Nov 20253
Diflufenican13018 Nov 20253
Diuron13018 Nov 20253
E. coli92119 Dec 20253
Enterococci92019 Dec 20253
Fluoride13018 Nov 20253
Free Chlorine92019 Dec 20253
Giardia2012 Feb 20251
Glyphosate13018 Nov 20253
Haloacetic acids (Sum of 5 HAAs)11018 Nov 20253
Iron92019 Dec 20253
Isoproturon13018 Nov 20253
Lead13018 Nov 20253
Linuron13018 Nov 20253
Manganese13018 Nov 20253
MCPA13018 Nov 20253
Mecoprop13018 Nov 20253
Mercury13018 Nov 20253
Metaldehyde13018 Nov 20253
Microcystin-LR8018 Nov 20253
Nickel13018 Nov 20253
Nitrate13018 Nov 20253
Nitrite (at tap)13018 Nov 20253
Odour80019 Dec 20253
PAH13018 Nov 20253
Pendimethalin13018 Nov 20253
Pesticides - Total13018 Nov 20253
pH92019 Dec 20253
Propyzamide13018 Nov 20253
Selenium13018 Nov 20253
Simazine13018 Nov 20253
Sodium13018 Nov 20253
Sulphate13018 Nov 20253
Sum of PFAS (sum of 20)11018 Nov 20253
Taste80019 Dec 20253
Tetrachloroethene & Trichloroethene13018 Nov 20253
Total Chlorine92019 Dec 20253
Total Organic Carbon13018 Nov 20253
Triclopyr13018 Nov 20253
Trihalomethanes(Total)13018 Nov 20253
Turbidity (at tap)92019 Dec 20253

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
01 Aug 2025Colour21Hazen20LOUGH MASK RWSS
2200PUB1032		191221
31 Jul 2025Coliform Bacteria1100ml0LOUGH MASK RWSS
2200PUB1032		190962
31 Jul 2025E. coli1100ml0LOUGH MASK RWSS
2200PUB1032		190962
13 Jun 2025Colour27Hazen20LOUGH MASK RWSS
2200PUB1032		181875

Common questions

Frequently asked questions

Is Westport 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 Westport?

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 Westport?

In 2025, monitoring data for 3 Water Supply Zones mapped to Westport included 1,945 results across 71 parameters. The separate EPA-listed exceedance dataset contains 4 records for those zones in 2025. These figures summarise historical records and are not a current safety verdict.

Who monitors drinking water quality in Westport?

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 Westport

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

CastlebarMayo · approximately 16.2 kmBallinaMayo · approximately 43.0 kmTuamGalway · approximately 54.1 kmGalwayGalway · approximately 65.2 kmOranmoreGalway · approximately 70.7 kmSligoSligo · approximately 86.4 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.

CastlebarLough Mask RWSS

How this page is made

Sources and methodology

Settlement
Census 2022 Built Up Area: Westport. 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