**1. Introduction**

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Water is vital to life and thus its availability and quality has increasingly been the object of intense concern and disputes by multiple agents that include from people directly relying on ecological services, or simply living in impacted zones, to influential non-governmental environmental organizations and regulatory governmental authorities. The scientific com‐ munity has increasingly intervened, particularly through the production of sound diagnostic and mechanistic data and also prognostic models, which fundamentally rely on both chemical and biological environmental monitoring. Despite the global increasing of pollution and its impacts, it appears that there is an uncontrollable expansion of anthropogenic activities, mainly in countries where there are no strict environmental policies. Therefore, pollution continues to negatively affect the quality of water and, in consequence, the vast ecosystems associated with it. Presently, it is estimated that hundreds of new chemicals with harmful potential are recorded daily in the CAS® (Chemical Abstracts Service, http://www.cas.org/ cashome). Thus, the subject "Water Quality" has been the target of many reflections, particu‐ larly in Europe, where in general, all state members of the European Union (EU) have shown their concern about the near future possibility of water shortages, for all, both in quantity and quality [1]. Related to this aspect, it is also recognized as of major importance the need to protect biodiversity and natural ecosystems; an example of such recognition is depicted in the 2012 European Parliament resolution on the "EU Biodiversity Strategy 2020" [2].

© 2015 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

In line with the referred intentions, at the beginning of the millennium the EU adopted legislation — the EU "Water Framework Directive" (WFD) [3] — that was considered very innovative at the time. The WFD called for a comprehensive and integrated approach of water protection and management, having as its ultimate goal that all European waters (continental surface waters, transitional waters, coastal waters and groundwaters) reached good chemical and ecological status within a 15 years period, since the date of publication of that directive. To achieve these requirements, temporal incremental goals were established amongst all EU states to ensure the success of this program. Thus, it was decided *inter alia* to: (*i*) apply all necessary measures to avoid the damage of superficial water bodies; (*ii*) impose fines on violators responsible for deteriorating the status of surface water bodies; (*iii*) achieve good ecological and chemical status for all artificial or heavily modified water bodies; (*iv*) progres‐ sively reduce the pollution of priority compounds, some of these focused in this Chapter, by limiting their emissions, their discharge and/or runoff into the environment.

However, as the water situation in each EU state was different and unique, since 2000 and up to the present, it has been necessary to make adjustments to overcome this aspect. Indeed, just one year after the WFD 2000/60/EC publication, this directive was updated [4]. In the renovated document (2455/2001/EC), among other measures, it was published a list containing thirtythree harmful compounds which presence in surface waters should be limited or at least/ reduced under limit values [4]. Among these compounds stands out the persistent organic pollutants (POPs), such as, pesticides, polycyclic aromatic hydrocarbons and alkylphenols. Later, the number of harmful compounds were expanded up to forty five and additional environmental quality standards were included in (2008/105/EC) [5]. Nonetheless, because further toxicity details each pollutant are becoming known, the number of compounds in the WFD list tends to increase. In this vein, the current directive 2013/39/EU integrates new substances in its watch lists [6]. Among those are EDCs such as the extremely potent 17βoestradiol (E2) and 17α-ethinylestradiol (EE2), as discussed in this Chapter.
