Urban Waste Water Treatment Directive

The Urban Waste Water Treatment Directive is a 1991 European Union directive concerning urban waste water "collection, treatment and discharge of urban waste water and the treatment and discharge of waste water from certain industrial sectors". It aims "to protect the environment from adverse effects of waste water discharges from cities and "certain industrial sectors".
It prescribes the waste water collection and treatment in urban agglomerations with a population equivalent of over 2000, and more advanced treatment in places with a population equivalent greater than 10,000 in "sensitive areas".
Description.
The Urban Waste Water Treatment Directive (full title "Council Directive 91/271/EEC of 21 May 1991 concerning urban waste-water treatment") is a European Union directive regarding urban wastewater collection, wastewater treatment and its discharge, as well as the treatment and discharge of "waste water from certain industrial sectors". It was adopted on 21 May 1991. It aims "to protect the environment from the adverse effects of urban waste water discharges and discharges from certain industrial sectors" by mandating waste water collection and treatment in urban agglomerations with a population equivalent of over 2000, and more advanced treatment in places with a population equivalent above 10,000 in sensitive areas.
Member states in the European Union maintain and operate waste-water treatment plants to conform to the Urban Waste Water Treatment Directive which sets standards for both treatment and disposal of sewage for communities of more than 200 person equivalents. Each member state is obliged to enact the requirements of the directive through appropriate local legislation. This directive also links to the Bathing Waters Directive and to the environmental standards set in the Water Framework Directive which are designed to protect all legitimate end uses of the receiving environment.
Sensitive areas.
The directive defines sensitive areas, as "freshwater bodies, estuaries and coastal waters which are eutrophic or which may become eutrophic if protective action is not taken", "surface freshwaters intended for the abstraction of drinking water which contain or are likely to contain more than 50 mg/l of nitrates", areas where further treatment is necessary to comply with other directives, such as the directives on fish waters, on bathing waters, on shellfish waters, on the conservation of wild birds and natural habitats, etc.
The directive contains a derogation for areas designated as "less sensitive"; such derogations were approved for areas in Portugal.
Implementation.
Member states were required to make waste water treatment facilities available 
In a 2004 Commission report on implementation by the member states, the Commission noted that some member states, in particular France and Spain, had been tardy in providing the required information, and infringement procedures had been initiated. The report mentioned Spain's non-provision of any advanced treatment in the catchment areas of rivers identified as sensitive in their downstream section, such as the Ebro and the Guadalquivir; Italy's implementation in the catchment area of the Po River, the delta and adjacent coastal waters; and the United Kingdom's interpretation and implementation of the directive in regard to the catchment areas of sensitive areas. Most member states planned to achieve conformity with the Directive by 2005 or 2008 at the latest.
Political significance.
The Urban Waste Water Directive marked a shift from legislation aimed at end-use standards to stricter legislation aimed at regulating water quality at the source. The directive applied both to domestic waste water and to waste water from industrial sectors, both of which account for much of the pollution. The Directive is an example of the detailed nature of European Union legislation and resulted in "significant costs in many member states".
Nine years after the directive was adopted, considerable variations remained in the provision of sewage treatment in the different member states.
Planned Revision.
On 13 July 2018, the European Commission published a Consultation on the Evaluation of the Urban Waste Water Treatment Directive ahead of a potential revision. Since its adoption in 1991, new technical advances on treatment techniques for waste and emerging pollutants have been identified that might require removal. In addition, the EU has since enlarged from 12 to 28 countries and new different experiences and challenges need to be taken into account.
However, the biggest challenge of the revision will be to exploit the potential the wastewater treatment sector can contribute to the circular economy agenda and the fight against climate change. Globally, the wastewater treatment sector consumes 1% of the global total energy consumption. Under a business as usual scenario, this figure is expected to increase by 60% by 2040 compared to 2014. With the introduction of energy efficiency requirements, the energy consumption of the wastewater treatment sector can be reduced by 50% only by using current technologies. On top of that, there are also opportunities to produce enough energy from wastewater to turn the whole water sector energy neutral. It uses the energy embedded in the sludge by producing biogas through anaerobic digestion. These features have been mainly overlooked due to the over-riding objective for utilities to meet existing and future needs for wastewater treatment.