Report No FR0238

Dec 1991

I OBJECTIVES

To provide the members of the FWR with information on the controls available for discharges to sewers in selected European countries.

II REASONS

Industrial discharges to sewers can have an effect on the sewerage system and the sewage treatment plant operation and can also influence the quality of the sewage sludge and effluent produced. With the increasing pressure to improve sewage effluent quality and the quality of sewage sludge to maintain the sludge outlets it is important to assess the approaches adopted in other countries to control discharges to sewers.

III CONCLUSIONS

The measures adopted to control industrial discharges to sewers vary widely between the countries investigated with Germany and The Netherlands having the most stringent, and Belgium the least stringent, controls. Only France operates an integrated pollution control approach for "scheduled" processes, however, this tends to be site specific. Self-monitoring is widely practised and toxicity based consents are increasingly being used in conjunction with the general chemistry based consents. The standards for discharges containing dangerous substances tend to be industry sector limit values based on "best available technology" (BAT). Compliance monitoring varies from two to six times per year, but may be increased for important discharges. Charges are usually based on cost recovery including the cost of compliance monitoring, however, where charges are levied for discharges to receiving waters these tend to be passed through to the discharges to sewers.

IV RECOMMENDATIONS

The actual sewage effluent and sludge qualities in terms of the concentrations of dangerous substances achieved should be reviewed for those countries with the most stringent controls to obtain a benchmark for the qualities achieved in the UK. The usefulness of applying toxicity based consents to discharges to sewers should be assessed.

V RESUME OF CONTENTS

The legislation and the responsibilities for controlling discharges to sewers are reviewed. The standards applied and the procedure adopted to issue and review consents are discussed. Information is also provided on the monitoring and charging approaches adopted and the measures available for dealing with exceedence of consents.

Copies of the report are available from FWR, price £35.00, less 20% to FWR Members.