Agenda and minutes

Apologies were received from Councillor Newby, Councillor Owen and Jack Board (SWW).

The minutes of the meeting held on 30 April 2014 were agreed. 

Minute No. 13

It was clarified that no complaints had been received by the City Council, but not necessarily via SWW direct.

There were no matters arising.

Ben Harris and Barbara Parsons attended the meeting to discuss the initial results of the odour survey.

There were 24 sites measuring amonia and hydrogen sulphide using diffusion tubes.  12 of these were sited within the SWW boundary, and 12 in residential areas. The tubes record the maximum and minimum concentration and will provide an average reading across the month.  The diffusion tubes have a greater sensitivity and the hydrogen sulphide readings were not picking up much more than the limit of detection.  There was a higher concentration in the Lower Wear Road area.

Ben Harris reported on the initial results, although the data would need to be analysed further.  Peaks, such as the 15-20 minute period on 9 June at 10.30pm, would be investigated further.  Customer complaints would also be linked in to the data, together with weather data including air pressure and site diaries.

The highest levels of amonia were near the sludge reception tank.  Concentrations had increased over the last two months for most readings, and there had been a peak of complaints in July.

Odours would not be detected if the monitors were placed inside residents’ houses.

Jay Harris reported that SWW had examined  processes which had been adjusted slightly to help minimise the risk of odours.  There was a potential problem with the sewer in the high odour area which could tie in with residents’ complaints and this would be examined further.

A brief report would now be produced detailing the outcome of the survey to date, and a final in depth report would be compiled at the end of the full six months.  It was anticipated that the final report could be expected at the end of October.

Scraper failure

Jay Harris reported on a recent scraper failure to tank no. 4 and that they were currently operating on three tanks.  It was anticipated that the tank would be fully operational within the next two days. 

Sludge had been present in the bottom of the tank when it was drained which generated odours.  However, the procedure had now been revised and the tank would be backflushed to remove the layer of sludge at the bottom in the event of a similar occurence.

Ian Ward advised that SWW had asked the company who supplies the scrapers to provide extra sensitivity in the detection of faults in future and they are investigating that option.

SWW had telephoned some complainants to advise of the fault and consideration was being given to ways of introducing an improved maintenance programme.

Digester clean

The digester clean had commenced.  The liming plant was operating as its replacement and was not producing any odour.  When the digesters are operational again, the majority of sludge would go through the existing process.

Pumping Stations

There would be aditional bolt ons at the works up until 2026 when Phase 3 of Cranbrook will be completed.  Another pumping station was being built at Clyst Honiton and there was also the facility at the Blue Ball pumping station.  The bolt ons would take place prior to development.

The Rydons pumping station was being monitored closely and levels had been adjusted at the pumps to reduce the risk of septic odours.  The lack of ventilation on site has had a detrimental impact on the equipment.  This was being monitored and other work is still needed for the adoption process. 

There had been a number of biological breakdowns in 2013 which led to a high number of complaints.  This year had seen physical mechanical breakdowns.

Over the period 30 April to 23 July there had been 33 complaints compared to 57 complaints in the same period last year.

Stuart Hunter asked the residents representatives if they were proactive to try to prevent odours, such as keeping windows closed.  It was noted that this is generally done, but the odours are still present in the house.

Reference was made to the notification of works, and any planned operation would be notified to this group and residents.  Jay Harris added that a number of ways to communicate problems or advance notification of works was being explored such as a text alert service.

Any complainants would be encouraged to report to ECC, who would liaise with SWW.

The next meeting was agreed as Tuesday 5 November 2014 at 2.30pm.