Turbidity in Drinking Water in Ireland
Explore EPA Ireland monitoring records, listed exceedances and historical trends for Turbidity in public drinking-water supplies across Ireland.
Turbidity describes the cloudiness of water.
- Latest monitoring year
- 2025
- Page updated
- September 2026
- Data available
- 2021, 2022, 2023, 2024, 2025
These are historical public-supply monitoring records, not a current water notice or a test of every household. Sampling locations can be outside the linked towns.
What do the latest results show?
The latest year is 2025. Results and listed exceedances are counted separately from their respective datasets.
- In 2025, 8,329 Turbidity monitoring results were recorded from 8,329 samples across 711 public water supplies.
- The separate EPA exceedance dataset lists 10 records across 9 schemes in 2025.
- There were 411 more monitoring results than in 2024 (5.2% more). This describes the volume of monitoring, not a change in water quality.
Turbidity at the tap and treatment works
Recorded results for 2025, with official requirements shown separately.
Irish drinking-water requirement
Requirements depend on the sampling location
At the tap: consumer acceptability and no abnormal change. For treatment of surface water, the regulations call for a value not exceeding 1 NTU in water leaving treatment. Schedule 2 also sets operational filtration reference levels; these are not a single limit for all samples.
This is separate guidance, not a test result for your own water. It does not reclassify historical records.
Official guidance checked 14 Sep 2026.
Monitoring coverage · 2025
- Numeric measurements
- 3,089
- EPA-listed exceedances
- 10
- Water supplies monitored
- 711
- First sample
- 02 Jan 2025
- Latest sample
- 22 Dec 2025
These are historical records, not the current status of your water. EPA-listed exceedances come from a separate dataset.
At-tap and water-treatment-works records describe different sampling settings. Neither series is a substitute for the other, and their recorded values are never added together.
Monitoring measurement units are not verified, so these recorded values cannot be compared with the official standard. Units in the listed exceedance table are reproduced separately from that source.
How to read these results
Measurement coverage · 2021–2025
The imported monitoring records have no unit field. These are counts of recorded values, not concentrations or a comparison with the standard.
19,096 numeric records; 20,962 censored text records; 61 other text-only records; 364 records without a result value.
31,450 records have a non-empty text field, including records that also have a numeric value. This overlapping field count must not be added to the numeric total.
| Year | Numeric | Non-empty text field | Censored text | Other text only | No result value |
|---|---|---|---|---|---|
| 2021 | 4,576 | 6,186 | 3,351 | 61 | 2 |
| 2022 | 4,177 | 6,187 | 4,069 | 0 | 9 |
| 2023 | 4,087 | 5,902 | 3,820 | 0 | 84 |
| 2024 | 3,167 | 6,173 | 4,565 | 0 | 186 |
| 2025 | 3,089 | 7,002 | 5,157 | 0 | 83 |
Monitoring history 2021–2025
Monitoring volume and listed exceedances have separate scales. Select a year to inspect its figures.
Across this period, 40,483 results from 40,464 samples cover 757 distinct water supplies. Sample dates run from 04 Jan 2021 to 22 Dec 2025.
20258,329 results · 10 listed exceedances · 711 schemes monitored
Turbidity (at tap)
Available years: 2021, 2022, 2023, 2024, 2025. Missing years are not zero observations.
Monitoring results — independent scale
EPA-listed exceedance records — independent scale
Turbidity (at WTW)
Available years: 2023, 2024. Missing years are not zero observations.
Monitoring results — independent scale
EPA-listed exceedance records — independent scale
These are record counts, not an official EPA compliance rate. The number and selection of samples and monitored schemes can change between years.
There were 411 more monitoring results than in 2024 (5.2% more). This describes the volume of monitoring, not a change in water quality.
| Year | Results | Samples | Schemes monitored | Listed exceedances | Schemes with listed exceedances |
|---|---|---|---|---|---|
| 2021 | 7,990 | 7,990 | 753 | 14 | 13 |
| 2022 | 8,255 | 8,255 | 734 | 17 | 16 |
| 2023 | 7,991 | 7,990 | 726 | 12 | 9 |
| 2024 | 7,918 | 7,900 | 719 | 9 | 8 |
| 2025 | 8,329 | 8,329 | 711 | 10 | 9 |
Separate source series
These are record counts for each source parameter. Values from different tests or sampling settings are not summed. A missing year is not a zero.
| Source parameter | Year | Results | Samples | Schemes | Listed records |
|---|---|---|---|---|---|
| Turbidity (at tap) | 2021 | 7,990 | 7,990 | 753 | 14 |
| Turbidity (at tap) | 2022 | 8,255 | 8,255 | 734 | 17 |
| Turbidity (at tap) | 2023 | 7,990 | 7,990 | 726 | 12 |
| Turbidity (at tap) | 2024 | 7,900 | 7,900 | 719 | 9 |
| Turbidity (at tap) | 2025 | 8,329 | 8,329 | 711 | 10 |
| Turbidity (at WTW) | 2023 | 1 | 1 | 1 | 0 |
| Turbidity (at WTW) | 2024 | 18 | 18 | 18 | 0 |
EPA-listed Turbidity exceedances
62 listed records across 46 distinct schemes, 2021–2025. These are historical sample records, not a current assessment of each property in a supply zone.
Results and limits below are reproduced from the separate EPA exceedance dataset, with its own reported units. These units are not assigned to the wider monitoring dataset.
| Year | Records | Schemes | Lowest listed result | Highest listed result | Reported unit | Reported limit |
|---|---|---|---|---|---|---|
| 2021 Turbidity (at tap) | 14 | 13 | 4.3 | 17.2 | NTU | 4 |
| 2022 Turbidity (at tap) | 17 | 16 | 4.07 | 18.6 | NTU | 4 |
| 2023 Turbidity (at tap) | 12 | 9 | 4.1 | 27.3 | NTU | 4 |
| 2024 Turbidity (at tap) | 9 | 8 | 4.5 | 24.8 | NTU | 4 |
| 2025 Turbidity (at tap) | 10 | 9 | 4.73 | 15.6 | NTU | 4 |
Show all 62 listed records 2021–2025 · newest first
| Date | Result | Reported unit | Reported limit | Water supply scheme | Scheme code |
|---|---|---|---|---|---|
| 02 Dec 2025 Turbidity (at tap) | 7.4 | NTU | 4 | Lough Talt Regional Water Supply | 2700PUB2702 |
| 28 Nov 2025 Turbidity (at tap) | 6 | NTU | 4 | Coolagown | 0500PUB1220 |
| 18 Nov 2025 Turbidity (at tap) | 4.94 | NTU | 4 | Cork City Water Supply | 0400PUB1001 |
| 18 Nov 2025 Turbidity (at tap) | 5.95 | NTU | 4 | Cork City Water Supply | 0400PUB1001 |
| 21 Oct 2025 Turbidity (at tap) | 7.8 | NTU | 4 | Galbally | 3300PUB1783 |
| 20 Oct 2025 Turbidity (at tap) | 6.03 | NTU | 4 | Kilmagnier | 0500PUB1210 |
| 23 Jun 2025 Turbidity (at tap) | 15.6 | NTU | 4 | DCC Zone 1 | 0700PUB1001 |
| 17 Apr 2025 Turbidity (at tap) | 4.73 | NTU | 4 | Owenteskna | 0600PUB1129 |
| 14 Apr 2025 Turbidity (at tap) | 11.5 | NTU | 4 | Knockeragh | 0500PUB1605 |
| 03 Jan 2025 Turbidity (at tap) | 5.47 | NTU | 4 | Belturbet PWS | 0200PUB0108 |
| 13 Aug 2024 Turbidity (at tap) | 5.04 | NTU | 4 | Crossmolina PWS | 2200PUB1013 |
| 14 May 2024 Turbidity (at tap) | 6.2 | NTU | 4 | Glaslough | 2400PUB1004 |
| 08 May 2024 Turbidity (at tap) | 5.9 | NTU | 4 | Shinrone/Brosna PWS | 2500PUB1019 |
| 24 Apr 2024 Turbidity (at tap) | 24.8 | NTU | 4 | Dungarvan | 3100PUB1039 |
| 08 Apr 2024 Turbidity (at tap) | 6.14 | NTU | 4 | Tuam RWSS | 1200PUB1047 |
| 08 Apr 2024 Turbidity (at tap) | 10.37 | NTU | 4 | Tuam RWSS | 1200PUB1047 |
| 03 Apr 2024 Turbidity (at tap) | 4.6 | NTU | 4 | ARKLOW PUBLIC SUPPLY | 3400PUB1004 |
| 14 Mar 2024 Turbidity (at tap) | 4.5 | NTU | 4 | Limerick City Environs PWS | 1900PUB1032 |
| 07 Feb 2024 Turbidity (at tap) | 5 | NTU | 4 | OLD FASSAROE PUBLIC SUPPLY | 3400PUB1073 |
| 05 Dec 2023 Turbidity (at tap) | 4.19 | NTU | 4 | ACHILL RWSS | 2200PUB1001 |
| 30 Nov 2023 Turbidity (at tap) | 27.3 | NTU | 4 | KILLAVANEY PUBLIC SUPPLY (TINAHELY) | 3400PUB1072 |
| 01 Nov 2023 Turbidity (at tap) | 8.4 | NTU | 4 | Slyguff | 0100PUB1178 |
| 17 May 2023 Turbidity (at tap) | 13 | NTU | 4 | Slyguff | 0100PUB1178 |
| 12 May 2023 Turbidity (at tap) | 5.6 | NTU | 4 | Three Mile House & Togan | 2400PUB2027 |
| 09 May 2023 Turbidity (at tap) | 4.43 | NTU | 4 | Cork City Water Supply | 0400PUB1001 |
| 24 Apr 2023 Turbidity (at tap) | 9.3 | NTU | 4 | Barrow/Poulaphouca Blend | 1400PUB1070 |
| 20 Apr 2023 Turbidity (at tap) | 4.9 | NTU | 4 | Galway City PWS | 1100PUB1001 |
| 13 Mar 2023 Turbidity (at tap) | 4.1 | NTU | 4 | West Clare Rws (New Wtp) | 0300PUB1066 |
| 07 Mar 2023 Turbidity (at tap) | 4.5 | NTU | 4 | Galway City PWS | 1100PUB1001 |
| 27 Feb 2023 Turbidity (at tap) | 17.9 | NTU | 4 | Slyguff | 0100PUB1178 |
| 16 Feb 2023 Turbidity (at tap) | 7 | NTU | 4 | Kilkerrin/Moylough | 1200PUB1031 |
| 24 Nov 2022 Turbidity (at tap) | 7.34 | NTU | 4 | Ballymoate Upper | 3100PUB1015 |
| 01 Sep 2022 Turbidity (at tap) | 12.8 | NTU | 4 | Slyguff | 0100PUB1178 |
| 15 Aug 2022 Turbidity (at tap) | 18.6 | NTU | 4 | KILLAVANEY PUBLIC SUPPLY (TINAHELY) | 3400PUB1072 |
| 04 Aug 2022 Turbidity (at tap) | 10.8 | NTU | 4 | Kereen | 3100PUB1057 |
| 20 Jul 2022 Turbidity (at tap) | 13.9 | NTU | 4 | Glashaboy | 0500PUB3303 |
| 20 Jul 2022 Turbidity (at tap) | 5.47 | NTU | 4 | Dunhill | 3100PUB1040 |
| 13 Jul 2022 Turbidity (at tap) | 4.09 | NTU | 4 | Cork Harbour & City | 0500PUB3401 |
| 29 Jun 2022 Turbidity (at tap) | 11.3 | NTU | 4 | Russelstown | 3100PUB1086 |
| 18 May 2022 Turbidity (at tap) | 4.07 | NTU | 4 | TINAHELY REGIONAL SUPPLY | 3400PUB1013 |
| 18 May 2022 Turbidity (at tap) | 16.4 | NTU | 4 | KILLAVANEY PUBLIC SUPPLY (TINAHELY) | 3400PUB1072 |
| 18 May 2022 Turbidity (at tap) | 9.06 | NTU | 4 | BALLYNAVORTHA PUBLIC SUPPLY | 3400PUB1168 |
| 12 May 2022 Turbidity (at tap) | 5.18 | NTU | 4 | Monaparson | 0500PUB1314 |
| 21 Apr 2022 Turbidity (at tap) | 4.75 | NTU | 4 | Kilballyowen (Aughrim) Public Supply | 3400PUB1081 |
| 23 Mar 2022 Turbidity (at tap) | 4.58 | NTU | 4 | THOMASTOWN PUBLIC SUPPLY | 3400PUB1042 |
| 15 Feb 2022 Turbidity (at tap) | 6.1 | NTU | 4 | Foxes Den Public Water Supply | 2700PUB2701 |
| 10 Feb 2022 Turbidity (at tap) | 5.01 | NTU | 4 | Carrignagower | 3100PUB1026 |
| 04 Jan 2022 Turbidity (at tap) | 6.11 | NTU | 4 | Limerick City Environs PWS | 1900PUB1032 |
| 11 Nov 2021 Turbidity (at tap) | 10.6 | NTU | 4 | Carrignagower | 3100PUB1026 |
| 02 Nov 2021 Turbidity (at tap) | 8.37 | NTU | 4 | Slyguff | 0100PUB1178 |
| 11 Oct 2021 Turbidity (at tap) | 9.74 | NTU | 4 | DCC Zone 3 | 0700PUB1004 |
| 16 Aug 2021 Turbidity (at tap) | 17.2 | NTU | 4 | Bruree PWS | 1900PUB1014 |
| 30 Jun 2021 Turbidity (at tap) | 9.67 | NTU | 4 | Kereen | 3100PUB1057 |
| 30 Jun 2021 Turbidity (at tap) | 7.21 | NTU | 4 | Poulavanogue | 3100PUB1082 |
| 25 May 2021 Turbidity (at tap) | 8.68 | NTU | 4 | Clogh-Castlecomer PWS | 1500PUB1005 |
| 10 May 2021 Turbidity (at tap) | 10.7 | NTU | 4 | Bruree PWS | 1900PUB1014 |
| 07 Apr 2021 Turbidity (at tap) | 5.1 | NTU | 4 | Nenagh RWSS | 2800PUB1008 |
| 15 Feb 2021 Turbidity (at tap) | 8.1 | NTU | 4 | Lios Cearnaigh PWS 052D | 1300PUB1028 |
| 07 Feb 2021 Turbidity (at tap) | 6.8 | NTU | 4 | Ballinakill 2 PWS | 1600PUB1101 |
| 01 Feb 2021 Turbidity (at tap) | 5.67 | NTU | 4 | Oola PWS | 1900PUB1043 |
| 12 Jan 2021 Turbidity (at tap) | 4.3 | NTU | 4 | Glashaboy | 0500PUB3303 |
| 11 Jan 2021 Turbidity (at tap) | 4.95 | NTU | 4 | Limerick City Environs PWS | 1900PUB1032 |
Places with mapped Turbidity monitoring data
Explore existing place reports with mapped Water Supply Zones containing Turbidity monitoring records in 2021–2025.
95 published places have at least one qualifying mapped zone. The 20 largest are listed below by Census 2022 population, not by Turbidity levels.
Places can share the same Water Supply Zone. These links do not represent independent city measurements; sampling locations may be outside the named Built Up Area. National totals above count each source record once.
DublinDublinCorkCorkLimerickLimerickGalwayGalwayWaterfordWaterfordDroghedaLouthDundalkLouthSwordsDublinNavanMeathBrayWicklowEnnisClareCarlowCarlowKilkennyKilkennyNaasKildareTraleeKerryNewbridgeKildareBalbrigganDublinPortlaoiseLaoisAthloneWestmeathMullingarWestmeath
View all places — the complete published place directory.
Sampling location matters for turbidity
At-tap and water-treatment-works records describe different sampling settings. Neither series is a substitute for the other, and their recorded values are never added together.
Current water information for your address
For current supply information, check your Eircode with Uisce Éireann. Follow the notice for your address: a Boil Water Notice and a Do Not Consume Notice have different instructions. This historical report does not recommend boiling as a treatment for chemical parameters.
Frequently asked questions
What does this Turbidity report cover?
40,483 monitoring records across 5 available monitoring year(s): 2021, 2022, 2023, 2024, 2025. The selected source is Turbidity (at tap), Turbidity (at WTW). National totals come directly from EPA records, not a sum of towns.
What is the Irish drinking-water requirement for Turbidity?
Requirements depend on the sampling location. At the tap: consumer acceptability and no abnormal change. For treatment of surface water, the regulations call for a value not exceeding 1 NTU in water leaving treatment. Schedule 2 also sets operational filtration reference levels; these are not a single limit for all samples.
Why are there two turbidity series?
The source distinguishes samples at the tap from those at the water treatment works (WTW). Each series retains its own coverage; years without WTW records are not shown as zero.
Can I compare the recorded Turbidity values with the standard?
Monitoring unit metadata have not been verified in this import. Numeric and censored records are counted separately; no concentration median, maximum or compliance rate is inferred from them. Listed records keep the units supplied by the separate EPA exceedance dataset.
Does a place link give the current Turbidity result at my address?
No. It identifies a place with a mapped supply and historical monitoring. It is not a test of every property. Check current Uisce Éireann supply information using your Eircode.
Sources and methodology
- Monitoring data
- EPA Ireland: drinking-water monitoring data: public-supply monitoring results and the separate listed exceedance records, 2021–2025.
- Water testing
- Uisce Éireann: drinking water tests
- Counting
- Source records are counted once across schemes. A sample is identified by its scheme, sample ID and date. Listed exceedances are not inferred from numeric results.
- Interpretation
- Text and censored results are not converted to numbers. Missing values are not zero. Records do not establish conditions in an individual home or an official compliance rate.