Public water supplies across Ireland contain some degree of chemical pollution and are known to cause avoidable health problems.The sources of contamination that lead to pollution include activities like farmingand industrial production, as well as disinfection of the water supply itself. With roughly 80% of the Irish population receiving their drinking water from the mains drinking water supply, we must acknowledge the risks so that we can start to ensure our drinking water is safe.
Water treatment plants disinfect water using chlorine, ultra-violet light, or ozone to remove waterborne bacteria such as E. coli. Unfortunately, these processes do not always remove all known pollutants.
The 4 common sources of unwanted chemical contamination
In Ireland, there are four common sources of chemical contamination that can pollute the public drinking water supply. These range from agricultural and industrial runoff, to the use of lead pipes to take water from the mains supply into homes and workplaces, to by-products of the disinfection process resulting in new chemicals entering the supply.
1. Agricultural runoff
Rain is not always absorbed through the soil.Instead, it runs into streams, rivers, and lakes, or it passes through cracks in the earth into the ground. This water is known as runoff,andit can pick up contaminants. If the runoff passes over a farm, these contaminants can include pesticides, fertilisers, and animal waste, and it becomes agricultural runoff. Agricultural runoff happens every time excessive rainwater causes water to flow across the topsoil and into waterways.
Agricultural runoff commonly enters surface water sources. Polluted rain water has led to a 3% decline in water quality across Ireland as 269 waterways — including rivers, coastal regions, canals and lakes — have experienced worsening conditions, with Cavan and Monaghan having the highest phosphorus levels in the region.
2. Urban and industrial runoff
Urban and industrial runoff is rainwater that flows across roads, construction sites, and factories, carrying pollutants from built-up areas into nearby waterways. Most developed areas have stormwater drains to channel rainwater away from buildings via a series of pipes and drainage streams. These systems help to reduce localized flooding and avoid erosion. However, they can carry contaminants from roads, chemicals from vehicles, pesticides and fertilisers from gardens, and bacteria from wastewater directly into local waterways.
As a result, urban and industrial runoff is a major source of pollution in streams, lakes, rivers, and reservoirs. That means anyone who drinks water from a private supply — which is 20% of the people in Ireland — or who lives or works near potential urban runoff, could be at risk.
3. Lead pipes
Irish Water has confirmed there are no lead water mains in Ireland. However, there are old lead pipes in the public network, including in homes and office buildings, which put the population at risk from lead poisoning.While it is difficult to estimate how many buildings have lead pipes, Irish Water recommends that if your building was built before the 1970s, there’s an elevated risk of lead pipes in the plumbing: the revelation comes as tests found unsafe levels of lead in drinking water across 30 areas of Ireland.
In 2018, analysis of drinking water near the Sutton Dart station, north of Co. Dublin, indicated lead contamination at nearly 15x the legal limit;while Coolock, Kilkeedy, and Rosses Point each saw lead concentrations well in excess of safe levels.The concern with lead plumbing is that water can corrode the pipes, causing lead to leach into the supply. Our bodies absorb the lead from the drinking water, causing anaemia, memory loss, kidney and heart disease, reduced fertility, even brain damage.
The metal is so toxic that the regulatory limit for lead in drinking water has reduced over time: it’s now just 10µg/L — and Irish Water is working to replace all public lead connections with plastic pipes as soon as possible.
4. Chlorine disinfection
Water treatment plants use chlorine to disinfect drinking water. It’s highly effective at eliminating bacteria and parasites. Plus, it ensures the water stays bacteria-free right up to when you pour it into your glass. However, chlorine can react with organic materials, like peaty soil, to create toxic compounds known as Trihalomethanes (THMs).
An information sheet from the HSE cites scientific research that indicates a link between long-term exposure to THMs and cancer, alongside other possible reproductive issues. However, the evidence remains inconclusive. Still, the European Commission has opened a case against Irish Water for its failure to control THM contamination of drinking water supplies across the country. While Irish Water has already paid a fine of €6,000for delaying remedial work at six treatment facilities to reduce the level of THMs in the water supply of thousands of people in Co. Donegal.
How can you reduce chemical contaminants in drinking water?
If you have reason to believe that you water is contaminated, contact your local water service provider to test your water.
Irish Water publishes several water quality reports every year. You can use them to keep track of the quality of your local water supply. Or, if you get your water from a private well, ask a specialist to test it for pollution, so you can select a water treatment solution based on the results
Additionally, water dispensers with carbon water filters are one of the most affordable, effective ways to remove most chemical contaminants like lead and industrial by-products.
Carbon filters work by passing the water through a permeable membrane that absorbs the pollutants. Water dispensers include a range of water purification technologies, guaranteeing you a drinking water supply that’s almost 99.9999% chemical and bacteria-free — making it the ideal solution when you want to be sure that every sip is safe.