Nitrate pollution of groundwater
Name(s):
Nitrate pollution of aquifers
Nature
Of the main nutrients in nitrogen, phosphorus and potassium fertilizers, nitrogen in the form of nitrate is the most common cause of degradation of groundwater near agricultural lands. Nitrate pollution also arises from the excessive application of animal or human excreta to the catchment of the aquifer.
Incidence
Despite an EEC/EU Directive on Drinking Water, the nitrate concentration in groundwater in shallow wells in the Netherlands, Belgium, Denmark and Germany will only reach an acceptable level in 25 to 50 years' time.
The intensive use of pesticides and fertilizers has led to chemicals being leached into freshwater supplies in many places. Nitrate pollution from excess fertilizer use is now one of the most serious water quality problems. Maximum allowable levels of nitrates in drinking water are exceeded in some places in every country in Europe (OECD 1994) and in many countries in other regions. Even in the United States, more than 40 million people obtained their drinking water in 1994 from a system in which there were violations of health-based standards, mainly those relating to nitrates. In some parts of Africa, nitrate loads in some suburban groundwater wells are 6-8 times WHO acceptable levels. Not only are nitrates dangerous to human health, leading to brain damage and even death in some infants (OECD 1994), but they stimulate rapid algal growth in waterways, leading to eutrophication in both inland waters and the sea.
Aggravates
Value(s)
Reference(s)
Type
(E) Emanations of other problems