The purpose of this project was to identify and trial a method of reducing odour levels generated by rising mains, so that costs associated with chemical dosing, can be reduced or eliminated. The method involved mechanical cleaning of the sewer internal surface using pipeline pigs, followed by chemical cleaning or periodical mechanical cleaning.
The research also investigated the effects of the cleaning on hydrogen sulphide levels (H2S) and odour, in the sewage / headspace, in the rising main downstream chamber. The performance of a pumping station, whilst undergoing mechanical cleansing in the pipeline, was identified and the risk elements assessed.
- Fuller understanding of H2S and odour levels in rising mains to reduce the problem.
- Reduced costs of dealing with odours in rising mains compared with chemical addition.
- Reduced complaints from residents in the vicinity of rising mains with a frequent odour issue.
- Assessment of the performance of this method enabled operators to make informed decisions on the cost / risk balance of undertaking cleaning versus chemical dosing.