A tranquil riverbank nestled in a corner of a farm just outside Limerick City would be idyllic if it wasn't the meeting place for such conflict.
Lush growth in the water offers a subtle sign of what the cause is. This is a place where the demands of agriculture, the environment and industry collide.
Follow the Barnakyle River down from this spot in the townland of Ballynoe, and it skirts around the village of Clarina before joining the Maigue for the last 6 km of its journey to the Shannon Estuary.
The spot sits on the land of dairy farmer Tom Ryan. He is well known in the sporting world as a former hurler with the Limerick team and he was a very high-profile manager of the side during a successful spell in the 1990s, when they won two Munster titles and narrowly lost two epic All-Ireland finals.
Today, his concerns are his livestock and his land. For more than a decade, Tom has complained to the authorities about the impact of the storm-water system on his land.
Flooding, and the effect of the residue left behind, are his primary concerns.
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Pollutants in the waters are promoting lush growth of vegetation.
The river, Mr Ryan told RTÉ Investigates, previously hummed with wildlife. There were fish and otters swimming in the river, ducks and pheasants breeding on the banks, and herons and egrets wading in the waters.
"Now there's a problem and we don't have any wildlife," Mr Ryan said.
Mr Ryan believes the problem lies up the Barnakyle Stream from the spot where the stream meets the river. Because, within a couple of kilometres, it is a different environment.
One of the main sources for this little tributary is the Loughmore Canal, a drainage channel constructed in the mid-1970s to serve the then-small Raheen Business Park, run by the now defunct Shannon Development.
Today, the IDA Business Park employs more than 6,000 people. It is home to local success stories and multinational firms.
The infrastructure built to carry off rainwater from the surface of the site was not designed with this level of expansion in mind. And that is the crux of the problem.
Along with rainwater, tests have shown high levels of zinc and phosphorous, along with other chemicals, in the surface water of the business park.
The IDA Business Park, home to local firms and multinationals, employs more than 6,000 people.
"There are over 100 businesses at the moment pumping into this," Sarah Mulcahy, whose farm is located across the road from the business park, told RTÉ Investigates.
"It was supposed to be about four to five businesses originally up there when the canal was first built."
It is through Ms Mulcahy's farm that the 1 km-long Loughmore Canal runs and it is where the business park's underground network of drainage pipes emerge from a culvert and flush out the surface water drains.
The dramatic increase in scale at the business park is set to continue. This year, pharmaceutical giant Eli Lilly received planning permission for its plans to build its first plant in Raheen, a new €400 million facility.
But Eli Lilly move into an estate where existing infrastructure is already strained, surface waters are contaminated and the IDA is at odds with local residents.
Further downstream from Ms Mulcahy, where the canal crosses under the smaller Caher Road, it becomes the Barnakyle Stream, just as it enters Mr Ryan's farm.
Mr Ryan says the prospect of the Park growing is not his primary concern if it creates more jobs but long-standing problems with drainage infrastructure need to be addressed.
Sarah Mulcahy's farm is located across the road from the business park.
"I have no problem with the plant being built across the road," he said, referring to Eli Lily's proposed new facility.
"I have a problem with the plants that are already there that are really and truly causing the problem and not putting their hand up."
For a long time, the problem was not clear. But long-running complaints eventually prompted an investigation in 2021.
This followed a complaint to the Environmental Protection Agency (EPA), which told the enforcement body in this area, Limerick City and County Council, to investigate.
Downstream testing, away from the business park, had been carried out in 2021. More than a decade earlier, the business park management, then Shannon Development, had studied the canal.
Both inquiries suggested that the nature of the contamination meant that it could be coming from downstream sources such as farming fertiliser, septic tanks or even run-off from the busy road.
This narrative changed in 2022 following a testing programme that went upstream, into the drainage channel network, and took water from a manhole inside Raheen Business Park.
It was in this manhole where contamination levels were highest.
Long-running complaints eventually prompted an investigation into pollution in 2021.
There were high levels of zinc. Phosphorus was, during one test, 20 times the EU limit for surface waters.
A report commissioned by the council, and carried out by environmental consultants, concluded that, because the pollutants detected in the canal were also present within the business park in higher concentrations, it was likely that industry was the root cause.
"Based on the area that is drained to Loughmore Canal (i.e. industrial estate), and anecdotal evidence of large water volume surges at intervals in the Canal, the source may be from one or more industrial units completing wash outs of equipment or containers using a phosphate and/or ammonia-based detergent," the report concluded.
Another engineer's report for the IDA, following its own testing programme, made a similar point.
"The phosphorus concentrations are higher than might be expected," it said.
"Given the absence of an agricultural element in the IDA estate, one possible source might be detergents, but if so these should be routed to the foul sewer system and not be allowed to enter the storm water."
But pollutants are entering the storm-water system and, the testing showed, these pollutants then find their way to the Loughmore Canal.
It is these pollutants – and the phosphorus in particular – that are promoting the lush growth of vegetation in its waters.
Pollutants detected in the canal were present within the business park in higher concentrations.
No individual business has been identified as a potential source for the releases.
Earlier this year, the Maigue River Trust wrote to the Council and said the canal contained "extraordinarily high levels" of pollutants and the infrastructure of the business park should be fit for purpose.
It said environmental laws must be enforced.
Surface water pollution is not unique to the Loughmore Canal. The EPA has highlighted issues with water quality across the county. But there is something unique about the canal's surroundings.
A National Parks and Wildlife Service has designated the land it cuts through, Loughmore Common, as a proposed Natural Heritage Area, because it is home to the only turlough in the area.
For anybody stumbling across it, the significance of Loughmore Common would be hard to spot. The turlough, what looks like an oversized puddle in the heart of the common, could be dismissed.
But turloughs are actually small surface portals to vast underground reservoirs and channels known as the ground water system.
This is an underground reservoir network used for drinking water supplies. It has been described as being extremely vulnerable in a status document for the Geological Survey of Ireland.
Dairy farmer Tom Ryan is well known for his involvement with Limerick hurling
The access the turlough provides to the priceless groundwater system is a particular concern, according to Eoin Brady, an environmental lawyer with FP Logue Solicitors.
That the turlough is linked to the groundwater, he said, has potential impacts for drinking water, given its proximity to the large urban area of Limerick City, he noted.
"A turlough presents particular issues from a public health and pollution point of view," he said.
"If pollutants are getting into the surface water element of the turlough, there's potential for them to move into the groundwater. So, from a legal point of view, turloughs have particular recognition under the water framework directive."
In the case of Loughmore, the link between the water in the man-made canal and the water in the turlough is real.
Although a bank appears to separate them, hydrological reports for the IDA and the council have concluded water flows between the two.
This is because the canal crosses underground sink holes, and it also floods.
The hydrological report for the IDA, on surface water compliance with the Water Framework Directive, said that, because of these connections, there was a link between the water in the canal and the Limerick Southwest Groundwater system.
Farmers are concerned about flooding and the effect of the residue left behind.
Turloughs are dotted across parts of Ireland but, strangely, are a feature seen virtually nowhere else in Europe.
As a turlough, Loughmore Common has been described in the official National Parks and Wildlife Service synopsis as being "unique", because of its location near the Shannon estuary and habitat for wintering birds
Mr Brady said that they are a point where surface water can mix with groundwater, so they have been given special protections in EU law under the Water Framework Directive and the Habitats Directive.
He said the law has put limits on what can be found in water for a reason.
Once the emission limits in the legislation are breached, Mr Brady said, there could potentially be a risk to both human health and the health of the ecosystem.
"That's why it's important that they're adhered to and where they're breached that there are measures taken to enforce those regulations."
At her farm, Ms Mulcahy is concerned that, currently, there is yet another link between what is in the canal and the environment outside it.
The canal is currently being dredged to remove a build-up of sediment and soil.
To help alleviate flooding and remove a build-up of sediment and soil clogging up the canal, it is currently being dredged under a licence from the National Parks and Wildlife Service.
But the soil that is being lifted and then left on the banks has been taken from the polluted canal.
While Ms Mulcahy acknowledged that the dredging may relieve the capacity, she said she is concerned that the contaminated soil will be left on the banks, and that the pollution will feed back into her land.
"It's just sitting on our bank. And then, in the first rain, I guess it just drains into our own farmland, which then goes to graze with the animals," she said.
In response to questions from RTÉ Investigates, the IDA said two ecologists, working on its behalf and the contractor, were on site to test the dredged material.
In relation to the wider issue of pollution, it said the root cause had not been found – but that it could be coming from a number sources.
Limerick City and County Council expects a report from the IDA on sampling from the business park.
The IDA said it "has been and remains committed to, working with [the council] to establish the source of any pollution" and that it would carry out "any remedial works" if required.
In Ireland, the regulatory system for water pollution is fragmented, and enforcement is split across all local authorities.
Mr Brady said this is a particular problem.
"I think the example of what we see in Limerick is fairly typical. You see a highly fragmented system, where we have many different laws that don't actually reflect the EU law. And so it's a significant problem – local authorities are wearing different hats," he said.
"They have got maybe an economic development hat on the one hand, and then a water pollution or environmental enforcement hat on the other. And often those two don't sit well together."
Local authorities have the power to injunct, demand action or even prosecute in cases of water pollution.
In Ireland, the regulatory system for water pollution is fragmented.
With respect to Raheen Business Park, Limerick City and County Council said in a statement that it was still working on the matter.
It said its investigation was "live and continuing". Referencing "the scale and nature of Raheen Industrial Estate and adjoining lands", it said it was working with the IDA and other stakeholders on all of the related issues.
It said it expects a report from the IDA on "targeted sampling from within the Business Park" imminently.
In the meantime, a mixture of legacy problems and new knowledge of the actual water content has left locals more concerned than ever.
"We were promised this time last year that it will be all sorted in a couple of weeks and they would get onto council and follow up," Ms Mulcahy said.
"But, unfortunately, we're here a year later and we're still looking at it and we are no closer to getting this resolved."
What the RTÉ Investigates report tonight on Prime Time at 9:35pm on RTÉ One and RTÉ Player.
