It comprises a prohibition on direct discharges to groundwater, and (to cover indirect discharges) a requirement to monitor groundwater bodies so as to detect changes in chemical composition, and to reverse any antropogenically induced upward pollution trend. The presumption in relation to groundwater is that it should not be polluted at all. For this reason, setting chemical quality standards are not seen as the best approach, as it would give the impression of an allowed level of pollution to which EU member states can fill up. Avery few such standards have been established at EU level for particular issues (nitrates, pesticides and biocides).