During August 1998 Aileen McGinn took her two golden retrievers, Kassie and Kelly, to play along the shoreline of the Blessington lakes in Co Wicklow. It was something she had done several times before. She was not to know that evening that perfect conditions existed for cyano-bacteria to form a bloom - a toxic scum - on the water.
Within half an hour Kassie was dead.
"According to our vet, it was as if she took strychnine. He knew it was from the water. There was no need to do a post-mortem. He had seen the symptoms so many times before," Ms McGinn recalls.
Since then she has fought single-handedly to highlight the risk water may pose, particularly to dogs. She is seeking, at the very least, warning signs at Blessington and elsewhere to make people aware of the dangers to animals and humans.
Almost all 35 miles of the lake shore are used throughout the year for fishing, rowing, boardsailing or canoeing by people from the immediate area and from Cos Wicklow, Kildare and Dublin and beyond.
The bloom usually appears as a scum on the water, sometimes frothy. Ms McGinn is aware of the possible implications the problem could have for much of Dublin's drinking water. The Department of the Environment issued an alert to all local authorities in 1993, but, notwithstanding this, she believes most State bodies are not confronting the problem and certainly "have not taken my concerns seriously", with the possible exception of the ESB, which owns the man-made lakes and uses their water at its Poulaphuca generating station.
She feels it is not an isolated problem, pointing to growing anecdotal evidence of other animal deaths around the country in recent years after they drank water from some of our best known lakes.
Aileen McGinn finds it hard to accept the Government is being commended at EU level for its "catchment management" approach to protecting key rivers and lakes. She feels not enough has been done to counteract the cyano-bacterial threat confronting so many of them.