It is important to know that your water supply is full of bugs, worms and plant slime. Their absence may indicate your water source is polluted.
Secondary school students visiting the Dundalk Institute of Technology yesterday heard about the collection of critters living in their local water supplies. The talk, by DkIT postgraduate researcher Caroline Wynne, was part of the institute's contribution to Science Week Ireland, which continues until Sunday.
The institute's National Centre for Fresh Water Studies works with group water schemes to help them improve the quality of their raw water input. "Treatment costs are lower if you have a clean water source," Ms Wynne said.
Water quality assessments are partly based on studying the various plants and animals living in the water source, she told her audience. "You can analyse water samples but this only gives you a snapshot of water quality at that moment."
The presence of worms, bugs and leeches plus microscopic algae known as diatoms gave a better assessment of what the water source was like over time. Identifying the types of animals in the water also provided useful information about water quality.
The EU funds her research group, which in turn is involved in a pilot study with the Churchhill and Oram water scheme. This scheme, located outside Castleblayney, Co Monaghan, serves about 250 homes, she said.
The water source in this case is Milltown Lake that, like many lakes, was under increasing pressure from pollution, mainly in the form of agricultural run-off. The research group studies plant and insect life in the water source to identify "pollution hot spots" that can then be tackled.
The idea was to introduce "low-cost low-technology" responses to reduce the localised pollution and so improve the overall quality of the water catchment.