Giardia in Drinking Water in Ireland

Explore EPA Ireland monitoring records, listed exceedances and historical trends for Giardia in public drinking-water supplies across Ireland.

Giardia is a microscopic parasite.

Latest monitoring year
2025
Page updated
September 2026
Data available
2021, 2022, 2023, 2024, 2025
1,094Monitoring results
1,094Samples
113Water supplies monitored
0EPA-listed exceedances

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.

  1. In 2025, 1,094 Giardia monitoring results were recorded from 1,094 samples across 113 public water supplies.
  2. The separate EPA exceedance dataset lists 0 records across 0 schemes in 2025.
  3. There were 296 more monitoring results than in 2024 (37.1% more). This describes the volume of monitoring, not a change in water quality.

Giardia monitoring and reported detections

Recorded results for 2025, with official requirements shown separately.

Official guidance

No single numerical value assigned here

No specific numerical Giardia parametric value. The regulations' general requirements for microorganisms and parasites still apply.

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
824
EPA-listed exceedances
0
Water supplies monitored
113
First sample
03 Jan 2025
Latest sample
23 Dec 2025

These are historical records, not the current status of your water. EPA-listed exceedances come from a separate dataset.

Uisce Éireann states that no specific numeric Giardia limit is designated in the directive. The general requirement concerning microorganisms and parasites remains relevant.

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.

2,898 numeric records; 1,921 censored text records; 23 other text-only records; 1 records without a result value.

4,542 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.

Result representation by year
YearNumericNon-empty text fieldCensored textOther text onlyNo result value
20214741,11669201
202250581538300
202361282328400
2024483756292230
20258241,03227000

Across this period, 4,843 results from 4,843 samples cover 176 distinct water supplies. Sample dates run from 02 Jan 2021 to 23 Dec 2025.

20251,094 results · 0 listed exceedances · 113 schemes monitored
Monitoring results — independent scale
0583.51,167 1,167 2021 888 2022 896 2023 798 2024 1,094 2025
1,167
2021
888
2022
896
2023
798
2024
1,094
2025
EPA-listed exceedance records — independent scale
000 0 2021 0 2022 0 2023 0 2024 0 2025
0
2021
0
2022
0
2023
0
2024
0
2025

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 296 more monitoring results than in 2024 (37.1% more). This describes the volume of monitoring, not a change in water quality.

Giardia monitoring, 2021–2025
YearResultsSamplesSchemes monitoredListed exceedancesSchemes with listed exceedances
20211,1671,16711200
20228888889600
202389689611200
20247987989900
20251,0941,09411300

EPA-listed Giardia exceedances

0 listed records across 0 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.

Listed exceedances by year and reported unit/limit pair
YearRecordsSchemesLowest listed resultHighest listed resultReported unitReported limit
No listed exceedance records in this period.
Show all 0 listed records 2021–2025 · newest first
All EPA-listed Giardia exceedances in the reporting period
DateResultReported unitReported limitWater supply schemeScheme code

Places with mapped Giardia monitoring data

Explore existing place reports with mapped Water Supply Zones containing Giardia monitoring records in 2021–2025.

47 published places have at least one qualifying mapped zone. The 20 largest are listed below by Census 2022 population, not by Giardia 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.

View all places — the complete published place directory.

No invented concentration limit

Uisce Éireann states that no specific numeric Giardia limit is designated in the directive. The general requirement concerning microorganisms and parasites remains relevant.

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 Giardia report cover?

4,843 monitoring records across 5 available monitoring year(s): 2021, 2022, 2023, 2024, 2025. The selected source is Giardia. National totals come directly from EPA records, not a sum of towns.

What is the Irish drinking-water requirement for Giardia?

No single numerical value assigned here. No specific numerical Giardia parametric value. The regulations' general requirements for microorganisms and parasites still apply.

Why is no numeric Giardia limit displayed?

A fixed concentration threshold has not been established by the cited guidance. This page preserves the source's listed records without inventing a per-volume standard.

Can I compare the recorded Giardia 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 Giardia 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.
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.