The latest statistics on drinking water quality in Donegal show that last year Aluminuim Levels in parts of the county were relatively high.
In parts of east Inishowen, some samples from the public water supply showed aluminium levels 20 times greater than that recorded in Letterkenny.
A sample taken from the water in Donegal Town showed an aluminium level 60 times the average of Letterkenny.
High levels of aluminium were also recorded in the Rosses - Gortahork areas.
It has been claimed that the high levels of aluminium found in the water supply in Donegal is due to the excess fluoridation of the water.
While for the most part Donegal's water complies with EPA guidlines, some groups have expressed concerns over the health risk and cost associated with adding flouride to drinking water.
Meanwhile e-coli was found present in the Ballintra water supply in the south of the county.