HELCOM RECOMMENDATION 8/3
Adopted 25 February 1987, having regard to Article 13, Paragraph b) of the Helsinki Convention
RECOMMENDATION CONCERNING MEASURES AIMED AT THE REDUCTION OF DISCHARGES FROM URBAN AREAS BY THE USE OF EFFECTIVE METHODS IN WASTEWATER TREATMENT
THE COMMISSION,
RECALLING Paragraph 1 of Article 6 of the Convention on the Protection of the Marine Environment of the Baltic Sea Area, 1974, (Helsinki Convention), in which the Contracting Parties undertake to take all appropriate measures to control and minimize land-based pollution of the marine environment of the Baltic Sea Area,
RECALLING ALSO Paragraph 1 of Annex III of the Helsinki Convention, in which the Contracting Parties agree to treat municipal sewage in an appropriate way so that the amount of organic matter does not cause harmful changes in the oxygen content of the Baltic Sea Area and the amount of nutrients does not cause harmful eutrophication of the Baltic Sea Area,
RECALLING FURTHER Paragraph 3 of Annex III of the Helsinki Convention, in which the Contracting Parties agree to minimize the polluting load of industrial wastes in an appropriate way in order to reduce the amount of harmful substances, organic matter and nutrients,
RECALLING FURTHER HELCOM Recommendation 6/7 concerning the treatment of municipal sewage and industrial wastewater with special emphasis on the reduction of discharges of nutrients,
RECOGNIZING the importance of municipal sewage as sources of pollution of the marine environment,
DESIRING to limit this pollution by effective treatment of municipal sewage,
RECOMMENDS to the Governments of the Contracting Parties to the Helsinki Convention that:
a) urban (municipal) wastewater deriving from households (domestic wastewater) or industrial enterprises should be collected and treated before being discharged into water bodies;
b) domestic sewage or wastewater of similar type which is collected in a central sewerage system should be treated as soon as possible by biological methods or other methods giving equivalent results, so that the treatment should result at least in (calculated as yearly average values with nitrification inhibitor, and calculated for total amount of sewage, including by-passes and overflow)
(i) 90% reduction of BOD5; and
(ii) a concentration of BOD5 in the effluent of the treatment plant below 15 mg/l;
c) reduction of phosphorus and nitrogen discharges should be carefully evaluated. As a start, treatment of municipal wastewater at plants serving more than 10 000 person equivalents should result as soon as possible in effluent yearly average values of total phosphorus below 1.5 mg P/1 calculated for total amount of sewage including by-passes and overflow;
d) for wastewater treatment plants, loaded with more than 10 000 person equivalents the possibility to improve the nitrogen removal capacity should be considered. Further recommendations should be developed concerning nitrogen removal as soon as possible;
e) the values stated in b), and c) need not be applied plantwise if a similar reduction in the total discharge of BOD5, and P as yearly average discharge values in
domestic sewage or wastewater of similar type which is collected in a central sewerage system can be documented,
RECOMMENDS FURTHER that reports of action taken by the Contracting Parties should be reported to the Commission one year after the adoption of this Recommendation and thereafter every 5 years.