The main sources for phosphates are rock-leaching ( carbonated contexts ), faecal contamination, domestic pollution ( detergents ) and agricultural pollution.

 

They are not toxic, but may lead to acceptance problems ( taste and colour ).

They may also participate in germ proliferation ( providing a nutrient salt ) and are essentially useful as an indication of faecal contamination.

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• AEP standard upper limit : 5 mg/l of P2O5