THE USE OF a bleaching chemical by a county council to disinfect streams near some of its popular beaches has been called into question by NGOs and a state agency amid “serious concerns” over its use.

Waterford City and County Council has said it uses sodium hypochlorite on streams near Dunmore East and Tramore in the summer bathing season, “primarily because children tend to play” in the streams, so it can attempt to sanitise the water.

However, other local authorities have told The Journal they avoid using the bleach: one called it “extremely toxic for aquatic life” while another said its use risked “destroying habitats”.

The issue has been raised by environmental NGO Coast Watch Ireland, which has contacted Waterford Council and the Environmental Protection Agency (EPA) on the use of sodium hypochlorite.

It is often used to treat water supplies and, as set out here by Irish Water, is not considered harmful when used for household water supply.

Its use can be controversial, as it is considered harmful to flora and fauna by a number of State agencies as well as NGOs like Coast Watch. Recently, The Journal’s sister site Noteworthy reported on concerns arising out of its intensive use at a power station upriver from Dunmore East.

Coast Watch and Inland Fisheries Ireland – the state agency responsible for rivers, lakes and other inland natural water bodies – have said they are “seriously concerned” at the use of the bleaching chemical to disinfect streams near popular beaches by Waterford Council.

Coordinator with Coast Watch Karin Dubsky alleged its use as an anti-foulant risked breaching the Water Pollution Act – something which Waterford Council vehemently denied.

“The other side of the desired germ kill action is that it acts as a water pollutant which kills not only the germs we want to kill but other  fresh water and marine life,” she told The Journal.

We know we can’t just focus on the useful aspects and ignore the risks and damage it does but don’t act fast enough to address the problems.

Dubsky said Coast Watch is now calling for the use of sodium hypochlorite to be “immediately halted” and for the EPA and other agencies to run an education and awareness programme for local authorities and landowners on the use of the chemical.

Coast Watch contacted Waterford Council after Dubsky, a marine ecologist, smelled chlorine during a visit earlier this month to the popular seaside village of Dunmore East.

But the council told this site it “disputes Coastwatch Ireland’s claim that it is in breach of the Water Pollution Act”, and stands by its use of the bleach. 

A spokeswoman said two streams flowing into the village’s bathing area have been chlorinated during the summer bathing season for “a number of years”.

This is due to an “unidentified” pollution source upstream of the beach.

“Waterford City and County Council is actively investigating the source of the contamination, however this is difficult to identify as it could be from a myriad of sources, e.g. agricultural run-off, sewage misconnections and / or poorly operated domestic waste water treatment systems,” the spokeswoman said. 

Marine ecologist Karin Dubsky (Coast Watch) Eoghan Dalton Eoghan Dalton

The council also contended that the chlorine is unlikely to affect flora and fauna in the bay.

It said: “The chlorine is driven off by the motion of the water and as such is unlikely to affect the flora and fauna in the bay and certainly not as much as some beach users leaving their rubbish, discarded plastics and other waste. 

“The stream is chlorinated upstream of the culvert to the beach [some 150m-200m away] primarily because children tend to play in the stream despite notices being erected advising adults / parents that it is unsafe to do so.

“The purpose of the chlorination plant is primarily to protect human health from the impact of diffuse pollution sources further upstream.” 

When asked whether it is used continuously or intermittently, it said the chlorination plants are only activated from around early June to mid-September and provide a “continuous metered service” depending on the water flows.

A view of the bay in Dunmore East, where there are concerns over the use of a bleaching chemical by the local council. Eoghan Dalton Eoghan Dalton

It said it also uses sodium hypochlorite the Pier in Tramore on a small stream that outfalls into the sea there.

Dubsky, of Coast Watch, said that when trying to ascertain the “consequences” for the environment it can be “exceptionally difficult to prove cause and effect” in a body of water as large and complex as the bay and estuary in the Dunmore area. 

“It’s in everyone’s interest to have clean life streams,” she said, adding that a national chlorine plan should be drafted setting out the clear use of the chemical. 

A spokeswoman for Inland Fisheries Ireland said it found the use of the chemical “very concerning” and added that it has appointed a Fisheries Environmental Officer from its South Eastern River Basin District to investigate and discuss the matter with Waterford City and County Council.

She said that members of the public are can report any suspected water pollution incidents by calling the body’s new 24/7 confidential hotline number on 0818 34 74 24.

While Waterford Council maintains the use of the chemical is normal, other local authorities were adamant they would not use sodium hypochlorite to disinfect their streams.

‘Environmentally unsound’

When contacted and asked whether it uses sodium hypochlorite to disinfect streams and water surfaces, Cork City Council said it is “extremely toxic to aquatic life” and it would never use it for that reason.

Dublin City Council also confirmed it does not use it, as did Wexford County Council.

The latter said it does not use sodium hypochlorite for disinfecting streams “for any reason” and to do so would be “environmentally unsound and destroy the habitats” in the water.

“We do not use hypochlorite or any chemical for disinfecting streams, for any reason. To do so would be environmentally unsound and destroy the habitats in the stream/river,” its press office said. 

Meanwhile, Cork City Council does not use sodium hypochlorite in streams, “or any other watercourses as it is extremely toxic to aquatic life”, a spokeswoman said.

“In fact, if chlorinated water needs to be discharged to the storm drainage system (e.g. when disinfecting water mains, cleaning reservoirs, testing processes within the water treatment plant etc), we require that water to be dechlorinated (typically using sodium thiosulfate) prior to discharge.”

The EPA said that “in general”, the use of a chemical in that fashion is “prohibited unless authorised”.

It added that “guidelines on the use of bleaches are not a matter for the EPA”.

Its press officer said: “In general under Irish legislation discharges to water which could cause pollution are prohibited unless authorised.

“Sodium hypochlorite is a disinfectant which may pose a risk to human health and the environment if present at levels in breach of drinking water or surface water standards.”