How concerned should we be about our ‘at risk’ public water supplies?
More than half a million people are drinking from “at risk” public water supplies, according to the Environmental Protection Agency (EPA). This means a supply might be fine today but there is no guarantee it will be in the future. Left unaddressed, a problem is inevitable because of lack of resilience.
The figures for 2023 show 57 supplies fall into this category with numbers affected up from 481,000 in 2022. This is despite Uisce Éireann, which is responsible for drink water supplies and wastewater treatment, investing more than €530 million last year in infrastructure and treatment systems.
How are problem areas identified?
The EPA’s remedial action list (RAL) identifies “at-risk” supplies that require improvements by Uisce Éireann to safeguard public health. Although 10 supplies were removed from the RAL last year following improvement works, the EPA, through its enforcement and assessment activities, identified a further nine “at-risk” supplies.
What are the most prevalent problems with drinking water?
It should be acknowledged the quality of drinking water remains very high, with more than 99.7 per cent of samples compliant with bacterial and chemical limits, but those exposed to poor supplies are consuming water with potentially serious health consequences.
Deterioration in supplies was mainly due to persistent levels of toxic trihalomethanes (THMs), which can arise when chlorine disinfectant interacts with organic matter, and the parasite cryptosporidium, which can make people severely ill – especially those with weak immune systems.
One in 20 supplies failed to meet the THM standard in 2023, affecting 300,000 people – an issue repeatedly highlighted by the EU and the EPA as the chemical has been linked in some studies to cancer. Ireland is before the European Court of Justice for failures to address THM levels. The problem is of particular concern where it is occurring in supplies to major population centres such as Limerick and Kilkenny.
The number of supplies where consumers have to boil water climbed to 46 in 2023, almost double the number in 2022. Meanwhile, progress to remove lead from our supply networks to protect public health is far too slow.
Should people served by at-risk supplies be worried?
Uisce Éireann has a rigorous programme of infrastructure improvements backed by enhanced testing, monitoring and assessing of supplies. But there are too many areas where problems are persisting or even worsening.
Although there is a timeline to bring problem areas up to standard, many thousands of people continue to be potentially exposed to debilitating illness which in some instances can be fatal.
As for THM risk, the utility works closely with the HSE to ensure its response is adequate while it addresses supplies exceeding EU limits. To date, a “do not drink” notice has not been imposed on any public water supply due to THM exceedances.
