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
Dundalk Tap Water Quality
EPA monitoring records for Water Supply Zones mapped to Dundalk contain 1,179 monitoring results across 68 parameters in 2025.
The separate EPA exceedance dataset contains 4 listed exceedance records across 3 parameters.
The most frequently listed were Trihalomethanes(Total) (2), Coliform Bacteria (1) and Colour (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 Zone
- Cavanhill
- Geographic overlap
- 83.01%
The Dundalk Built Up Area overlaps Cavanhill across approximately 83.01% of its land area.
Monitoring results apply to the Water Supply Zone as a whole and may include sampling locations outside Dundalk.
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 maximum1
Measurements in 20255
0 EPA-listed exceedances in 2025.
View parameter history
Nitrate
2025 median10.1
2025 maximum13.11
Measurements in 20255
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
E. coli
2025 median0
2025 maximum0
Measurements in 202566
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
Coliform Bacteria
2025 median0 100ml
2025 maximum2 100ml
Measurements in 202566
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
Fluoride
2025 median0.7 mg/l
2025 maximum0.8 mg/l
Measurements in 20255
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
Iron
2025 median21.5 ug/l
2025 maximum180 ug/l
Measurements in 202566
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
Arsenic
2025 median—
2025 maximum—
Measurements in 20255
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
Monitoring over time
5-year trends 2021–2025
Available years in the latest 5-calendar-year window. Monitoring volume and descriptive frequency use separate scales.
20251,179 results · 4 listed exceedances
Total results — independent scale
Listed exceedances per 1,000 results — independent scale
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.
| Year | Results | Samples | Parameters | Listed exceedances | Per 1,000 results |
|---|---|---|---|---|---|
| 2021 | 1,089 | 84 | 65 | 19 | 17.447 |
| 2022 | 1,087 | 74 | 64 | 10 | 9.200 |
| 2023 | 1,329 | 81 | 65 | 10 | 7.524 |
| 2024 | 1,080 | 60 | 65 | 9 | 8.333 |
| 2025 | 1,179 | 66 | 68 | 4 | 3.393 |
Year-to-year detail
2025 compared with 2024
Changes describe dataset volumes only. The comparison uses the previous available year.
Results
20241,080
20251,179
Listed exceedances
20249
20254
Samples
202460
202566
Parameters
202465
202568
Parameters with EPA-listed exceedances
Values and limits are reproduced as reported. Different unit/limit pairs are shown separately.
Trihalomethanes(Total)
2 listed exceedance records / 5 tests40.00%
Descriptive frequency of records, not an official compliance measure.
- Highest listed result
- 108 ug/l
- Reported limit
- 100 ug/l
- Records with this unit/limit pair
- 2
- Latest exceedance
- 03 Oct 2025
Coliform Bacteria
1 listed exceedance records / 66 tests1.52%
Descriptive frequency of records, not an official compliance measure.
- Highest listed result
- 2 100ml
- Reported limit
- 0 100ml
- Records with this unit/limit pair
- 1
- Latest exceedance
- 18 Jul 2025
Colour
1 listed exceedance records / 66 tests1.52%
Descriptive frequency of records, not an official compliance measure.
- Highest listed result
- 21 Hazen
- Reported limit
- 20 Hazen
- Records with this unit/limit pair
- 1
- Latest exceedance
- 13 Jan 2025
Across the year
When were listed exceedances recorded?
Each point represents one listed exceedance record. Records on the same date remain separate.
Trihalomethanes(Total)03 Oct 2025
108 ug/lReported result
100 ug/lReported limit
CavanhillWater supply
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.
Cavanhill
83.01% geographic overlap with the Dundalk Built Up Area.
Technical mapping details
Detailed data
The complete parameter and listed exceedance tables for the reporting year.
68 parameter rows4 listed exceedance records66 samples
Show detailed data68 parameters · 4 exceedance records
Complete parameter index
All parameters in 2025
| 1,2-dichloroethane | 5 | 0 | 03 Oct 2025 | 1 |
| 2,3,6-trichlorobenzoic acid | 5 | 0 | 03 Oct 2025 | 1 |
| 2,4-D | 5 | 0 | 03 Oct 2025 | 1 |
| Acrylamide | 5 | 0 | 03 Oct 2025 | 1 |
| Aluminium | 66 | 0 | 19 Dec 2025 | 1 |
| Ammonium | 5 | 0 | 03 Oct 2025 | 1 |
| Antimony | 5 | 0 | 03 Oct 2025 | 1 |
| Arsenic | 5 | 0 | 03 Oct 2025 | 1 |
| Atrazine | 5 | 0 | 03 Oct 2025 | 1 |
| Bentazone | 5 | 0 | 03 Oct 2025 | 1 |
| Benzene | 5 | 0 | 03 Oct 2025 | 1 |
| Benzo(a)pyrene | 5 | 0 | 03 Oct 2025 | 1 |
| Bisphenol A | 5 | 0 | 03 Oct 2025 | 1 |
| Boron | 5 | 0 | 03 Oct 2025 | 1 |
| Bromate | 5 | 0 | 03 Oct 2025 | 1 |
| Cadmium | 5 | 0 | 03 Oct 2025 | 1 |
| Chlorfenvinphos | 5 | 0 | 03 Oct 2025 | 1 |
| Chloride | 5 | 0 | 03 Oct 2025 | 1 |
| Chromium | 5 | 0 | 03 Oct 2025 | 1 |
| Clopyralid | 5 | 0 | 03 Oct 2025 | 1 |
| Clostridium Perfringens | 5 | 0 | 03 Oct 2025 | 1 |
| Coliform Bacteria | 66 | 1 | 19 Dec 2025 | 1 |
| Colony Count @ 22°C | 61 | 0 | 19 Dec 2025 | 1 |
| Colour | 66 | 1 | 19 Dec 2025 | 1 |
| Conductivity | 66 | 0 | 19 Dec 2025 | 1 |
| Copper | 5 | 0 | 03 Oct 2025 | 1 |
| Cyanide | 5 | 0 | 03 Oct 2025 | 1 |
| Cypermethrin | 5 | 0 | 03 Oct 2025 | 1 |
| Dichlobenil | 5 | 0 | 03 Oct 2025 | 1 |
| Dichlorprop | 5 | 0 | 03 Oct 2025 | 1 |
| Diflufenican | 5 | 0 | 03 Oct 2025 | 1 |
| Diuron | 5 | 0 | 03 Oct 2025 | 1 |
| E. coli | 66 | 0 | 19 Dec 2025 | 1 |
| Enterococci | 66 | 0 | 19 Dec 2025 | 1 |
| Fluoride | 5 | 0 | 03 Oct 2025 | 1 |
| Free Chlorine | 66 | 0 | 19 Dec 2025 | 1 |
| Glyphosate | 5 | 0 | 03 Oct 2025 | 1 |
| Haloacetic acids (Sum of 5 HAAs) | 5 | 0 | 03 Oct 2025 | 1 |
| Iron | 66 | 0 | 19 Dec 2025 | 1 |
| Isoproturon | 5 | 0 | 03 Oct 2025 | 1 |
| Lead | 5 | 0 | 03 Oct 2025 | 1 |
| Linuron | 5 | 0 | 03 Oct 2025 | 1 |
| Manganese | 5 | 0 | 03 Oct 2025 | 1 |
| MCPA | 5 | 0 | 03 Oct 2025 | 1 |
| Mecoprop | 5 | 0 | 03 Oct 2025 | 1 |
| Mercury | 5 | 0 | 03 Oct 2025 | 1 |
| Metaldehyde | 5 | 0 | 03 Oct 2025 | 1 |
| Nickel | 5 | 0 | 03 Oct 2025 | 1 |
| Nitrate | 5 | 0 | 03 Oct 2025 | 1 |
| Nitrite (at tap) | 5 | 0 | 03 Oct 2025 | 1 |
| Odour | 61 | 0 | 19 Dec 2025 | 1 |
| PAH | 5 | 0 | 03 Oct 2025 | 1 |
| Pendimethalin | 5 | 0 | 03 Oct 2025 | 1 |
| Pesticides - Total | 5 | 0 | 03 Oct 2025 | 1 |
| pH | 66 | 0 | 19 Dec 2025 | 1 |
| Propyzamide | 5 | 0 | 03 Oct 2025 | 1 |
| Selenium | 5 | 0 | 03 Oct 2025 | 1 |
| Simazine | 5 | 0 | 03 Oct 2025 | 1 |
| Sodium | 5 | 0 | 03 Oct 2025 | 1 |
| Sulphate | 5 | 0 | 03 Oct 2025 | 1 |
| Sum of PFAS (sum of 20) | 5 | 0 | 03 Oct 2025 | 1 |
| Taste | 61 | 0 | 19 Dec 2025 | 1 |
| Tetrachloroethene & Trichloroethene | 5 | 0 | 03 Oct 2025 | 1 |
| Total Chlorine | 66 | 0 | 19 Dec 2025 | 1 |
| Total Organic Carbon | 5 | 0 | 03 Oct 2025 | 1 |
| Triclopyr | 5 | 0 | 03 Oct 2025 | 1 |
| Trihalomethanes(Total) | 5 | 2 | 03 Oct 2025 | 1 |
| Turbidity (at tap) | 66 | 0 | 19 Dec 2025 | 1 |
Showing 68 of 68 parameters.
EPA exceedance dataset
Listed exceedances in 2025
Newest first. Sample IDs distinguish records that may otherwise look identical.
| Date | Parameter | Result | Unit | Reported limit | Water supply / EDEN | Sample ID |
|---|---|---|---|---|---|---|
| 03 Oct 2025 | Trihalomethanes(Total) | 108 | ug/l | 100 | Cavanhill 2100PUB1018 | 2389/2510623/01 |
| 01 Aug 2025 | Trihalomethanes(Total) | 101.9 | ug/l | 100 | Cavanhill 2100PUB1018 | 2389/2508557/01 |
| 18 Jul 2025 | Coliform Bacteria | 2 | 100ml | 0 | Cavanhill 2100PUB1018 | 2389/2507543/01 |
| 13 Jan 2025 | Colour | 21 | Hazen | 20 | Cavanhill 2100PUB1018 | 2389/2501461/01 |
Common questions
Frequently asked questions
Is Dundalk 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 Dundalk?
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 Dundalk?
In 2025, monitoring data for the Water Supply Zone mapped to Dundalk included 1,179 results across 68 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 Dundalk?
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 Dundalk
Nearest published Built Up Areas, ordered by straight-line distance between Census reference points.
How this page is made
Sources and methodology
- Settlement
- Census 2022 Built Up Area: Dundalk. 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.