Report No FR0030

Aug 1989

I OBJECT

To provide practical guidance to the Water Industry on the performance and selection of sewer cleaning techniques.

II REASON

There is concern and a general lack of guidance within the industry about the overall effectiveness of cleaning and specifically the operational effectiveness of different techniques and equipment.

III CONCLUSIONS

There are many interdependent factors which influence the effectiveness of sewer cleaning operations. Whilst these have been identified there is no impartial evidence about the degree of interdependence.

There is general agreement about the broad uses of high pressure/low volume and low pressure/high volume water jetting units but there is uncertainly about the limitations of particular units.

Little impartial research has been carried out on the effectiveness of the more recently developed debris removal equipment.

There are no agreed definitions of debris type and no consistency of approach in contract documentation.

Quality assurance systems are needed to check performance against the specifications.

IV RECOMMENDATIONS

Impartial, co-ordinated trials of jetting units should be undertaken. Tests of different types of jetting head should also be undertaken to assess their effectiveness.

A code of practice should be prepared to standardise contracts.

Quality control procedures should be produced and trials undertaken.

Copies of the report are available from FWR, price £15.00, less 20% to FWR Members.