Llyn Padarn Latest
At a meeting of the Llyn Padarn Stakeholder Group, the Environment Agency Wales (EAW), outlined the steps they are taking to continue monitoring the nutrient levels in Llyn Padarn, and the necessary work required to determine what is the sustainable level of phosphates (primarily) the lake can tolerate without leading to blue green algae blooms.
As well as a potential public health risk, blue green algae can result in deoxygenation of the water column, ultimately resulting in eutrophication
and aquatic life dying. In early December
EAW collected over 10,000 Arctic Char fish eggs to safeguard the future of this protected species.
Speaking at Parc Menai, Dŵr Cymru said they had taken several proactive steps to improve the effeciency of the sewage works at Afon y Bala that discharges treated effluent into the lake; despite having been meeting the environmental standard laid down by EAW.
However, the sewage treatment plant has always worked well during the winter and it's not known if the recent gains in efficiency will be as effective during the summer when the population of Llanberis goes up and the temperature increases. The consent discharge level (average) for phosphate levels set by EAW will soon be lowered from 1.6 mg/litre to 1 mg/litre. Interestingly, Dŵr Cymru gave a percentage breakdown of phosphate sources at the treatment works: 65% natural (human waste), 25 - 30% from detergents, toothpaste etc. and 10% from dringking water (added to reduce solubility of lead).
Temperature spikes noticed by EAW at Afon y Bala from water entering the lake from Llyn Peris are also being looked at and it's not known if these have any environmental impact. The Countryside Council for Wales (CCW) are expecting the results back in April from diatom core analysis of the lake sediments that will provide a historical record of the nutrient levels in Padarn.
Until a nutrient model of Llyn Padarn has been established by EAW, they reported that it is not possible to say what can be set as the sustainable level for the lake.
Phil Nelson from Surf-Lines, who runs an outdoor activity business on the lake shore, said: "I'm pleased that immediate steps are being taken to lower the phosphate discharge levels before the modelling is completed but I can't afford to loose thousands of pounds again if it returns."
There is also the issue of phosphates remaining within the lake (sediment etc.) from last summer and how long it will take for these levels to diminish. A further meeting has been set for the start of May.Related News Items: Llyn Padarn Forum, Blue Green Algae Latest, Red Alert.Photo:
The lower temperatures and increased rainfall you'd expect over autumn and winter has meant the lake has been given the 'all-clear' but there is concern about the blue green algae returning this summer. © Ray Wood
Topic: Blue Green Algae, Llyn Padarn, Snowdonia Lakes.
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