Implementation EC Urban Waste Water Treatment Directive
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The Council Directive 91/271/EEC concerning urban wastewater treatment was adopted on 21 May 1991. It's objective is to protect the environment from the adverse effects of discharges and discharges from certain industrial sectors (see Annex III of the Directive) and concerns the collection, treatment and discharge of:
- Domestic waste water
- Mixture of waste water
- Waste water from certain industrial sectors (see Annex III of the Directive)
Specifically the Directive requires:
- The Collection and treatment of waste water in all agglomerations of >2000 population equivalents (p.e.);
- Where the establishment of a collecting system is not justified either because it would produce no environmental benefit or because it would involve excessive cost, individual systems or other appropriate systems which achieve the same level of environmental protection shall be used;
- Secondary treatment of all discharges from agglomerations of > 2000 p.e., and more advanced treatment for agglomerations >10 000 population equivalents in designated sensitive areas and their catchments;
- A requirement for pre-authorisation of all discharges of urban wastewater, of discharges from the food-processing industry and of industrial discharges into urban wastewater collection systems;
- Monitoring of the performance of treatment plants and receiving waters; and
- Controls of sewage sludge disposal and re-use, and treated waste water re-use whenever it is appropriate.
Situation in the Netherlands
Municipalities maintain and controle the public sewerage systems. The management of public UWWP’s and the quality of surface waters is the duty of the Waterboards. In the Netherlands we have an extensive sewerage system connected to urban waste water treatment plants (UWWP). The main part of the sewer waste water comes from dutch households. A small part comes from industries and draining off rainwater. Not all the wastewater is collected in a sewer system. Outlying households discharge on surface water or on soil. Before discharge this waste water is always treated in an individual waste water treatment system (a septic tanc or a small biological treatment of waste water). The Netherlands comply hereby the Council Directive for all p.e.
Problems with overflows
Not all the waste water collected in a sewerage system reach an UWWP. With heavy rainfall sewerage systems run over, which causes overflows in the surface water. In some cases this happens frequently. The last years policy has been made to reduce these overflows of waste water. The fact that there are too many overflows in Dutch sewerage systems, is caused by the widespread system and the fact that all kinds of waste water are discharged on this system. To reduce overflows legislation is made to ensure clean groundwater and rainwater is not collected in a sewerage system. This legislation includes a preference to let this clean water flow back in/on soil or into surface water. Furthermore the legislation includes an ensurance that only industrial waste water witch contains biological compounds (and witch is similar to domestic waste water ) that can be treated in a public UWWP. Other industrial waste water has to be treated in industrial waste water treatment plants (owned by the companies). These preferences of waste water are implemented in the Environmental Protection Act (EPA) and contains the following steps:
- Prevention production
- Prevention pollution
- Separated collection
- Domestic waste water, other water similar to domestic waste water collected in a public sewer system and UWWP
- Other waste water: owner responsible, preverence return into the environment
