NITRATES

Water resource contamination has become a very real problem in the pas t few years, particularly in industrialised countries where the survey of water quality frequently indicates rising nitrate concentrations. This evolution has entailed numerous public interrogations and in this context, two issues must be considered: a public health issue, as nit rate concentrations in water resources frequently exceed the 10 mg N/I limit defined in most countries as one of the drinking water quality standards. Even if nitrate is not directly toxic for humans, this limi t is kept on the basis of the precautionary principle. At present its adherence compels water suppliers to take specific treatment measures. an environmental issue as water contamination with nitrate may lead t o alga blooms in the resource. These modifications of the ecosystem ma y persist and create activities that impact upon the water resource.