HELCOM RECOMMENDATION 7/5

Adopted 11 February 1986, 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 TREATMENT OF STORMWATER

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 Contracating 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 HELCOM Recommendation 5/1 regarding limitation of oil in stormwater systems,

RECOGNIZING the need for limiting harms caused by the quality of stormwater discharged to the Baltic Sea Area,

RECOMMENDS to the Governments of the Contracting Parties to the Helsinki Convention that:

a) measures should be taken already at the source to prevent the deterioration of the quality of stormwater (e.g. efficient dry street cleaning and reduction of lead in petrol);

b) where a stormwater in a separate system district is collected from areas with high traffic

(i) flow equalization units should be provided whenever possible for the first flush of stormwater; and

(ii)   this water be conveyed to sewage treatment plant;

c) contaminated stormwater from heavily polluted industrial areas (loading, unloading, storing) should be treated as polluted wastewater;

d) all possible means should be taken to minimize the volume of stormwater entering combined sewer systems (minimization of the volume could be reached for instance by local infiltration);

e) in areas with combined sewer systems overflow should be prevented as far as possible by appropriate designing of the sewerage system and providing retention facilities,

RECOMMENDS FURTHER that the 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.