Following receipt of the Cranleigh Civic Society’s Odour Assessment Survey, Surrey County Council Planning Enforcement Team are now investigating whether Thames Water should have applied for planning permission, and carried out a full odour impact assessment, prior to expansion at Cranleigh’s Sewage Treatment Works.


Background to Survey

On 8 May 2016 representatives from Cranleigh Civic Society, Cranleigh Parish Council, the Surrey Wildlife Trust and Waverley Borough Council met with Thames Water and the Environment Agency at Cranleigh Sewage Treatment Works (STW) on Elmbridge Road, to discuss capacity issues and concerns about pollution from the liquid effluent discharge (by-product of sewage treatment) into Cranleigh Waters.

At that meeting Thames Water confirmed that the STW was being expanded from 6 filter beds to 8, a 30% increase in filtration capacity, to improve resilience at the SWT in response to capacity issues.

Cranleigh Civic Society pointed out to Thames Water that when some minor works were done in 2010, Thames Water had needed to apply for Planning Permission and had carried out an Odour Impact Assessment, triggered by a number of odour complaints they had received previously from residents.  Thames Water were asked why they had not followed this process for the current works and they advised us that it was classed as “permitted development”.  However, we have continued to have doubts as to whether this information was correct.

Odour Survey and Results

At the beginning of July 2016, Cranleigh Civic Society carried out our own survey to find out whether there still was a problem with odour problems from the sewage works.

We delivered 330 forms to households within an 800m radius of the Cranleigh Sewage Treatment Works (STW), 104 survey forms (32%) were returned.

The aim of the survey was to identify if residents had existing odour nuisance problems, whether they had reported these to Thames Water or Waverley Borough Council and whether they were aware of the enlargement work being carried out at Cranleigh sewage treatment plant.

Of the respondents, 71% of households had experienced odour problems, however only 16% of households had complained directly to Thames Water or Waverley Borough Council about the issue, and 93% wanted Thames Water to carry out a full Odour Impact Assessment before proceeding with further work on site.

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Of the 71% of households who said that odours from Cranleigh STW have been a nuisance,  47 households went on to say that, on a scale of 1 to 5, where 5 is “very offensive”, that they rated the odour nuisance at 4 or 5.

97% of households said that they had not been made aware by Thames Water that Cranleigh STW was being expanded.

The survey results indicated that currently there is a high level of concern from residents living within 800m concerning the odours emanating from the STW.

It also highlighted the number of residents that fail to report odours, therefore reliance on the level of complaints to Thames Water cannot be taken as indicative of the true number of households affected by this ongoing problem.  One resident replied “I didn’t know I could complain”.

The survey also identified the detrimental impact on residents’ enjoyment of their property. This distressing nuisance is particularly prevalent on warm summer evenings when residents living near the STW report having to close their windows, of mosquito infestations and being unable to sit in their garden due to the overwhelming and offensive odour of sewage.

Against this background and the advice given in DEFRA’s “Odour Guidance for Local Authorities, 2010”, we have submitted the survey results to Waverley Borough Council for them to investigate.

We received the following response on 29 September 2016 from Waverley’s Planning Enforcement Officer


“TOWN AND COUNTRY PLANNING ACT 1990 (AS AMENDED)

RE: CRANLEIGH SEWAGE TREATMENT WORKS

Further to our previous correspondence regarding the site I have now had the opportunity to discuss with colleagues at Surrey County Council and have been informed that they are the appropriate Planning Authority to investigate the matter.

They have requested that your complaint be emailed directly to mwcd@surreycc.gov.uk please include the full details of your concerns together with any reasoning as to why you believe there to be a breach of planning control. Once they have received the enquiry they open a case for action.

Please be informed that unless I am informed to the contrary, because we are not the most appropriate authority to investigate, the complaint case C/2016/00257 will be recommended for closure.

Should you have any further queries please do not hesitate to contact me and I will direct your concerns as best I can.”


On 30 September 2016 we then received notification from Surrey County Council’s Senior Planning Enforcement Officer that the matter had been passed on to him by Waverley and he confirmed that:


I can inform you that the County Planning Authority (CPA) have requested full details of works from Thames Water.  On receipt of requested information the CPA will be assessing the position with regard to Permitted Development Rights or alternatively if there is a need for formal planning consent.  Officers also intend to visit the site to view the works.

Following consideration of this matter, the CPA will advise you of its findings.”


We now await the outcome of their investigations with interest.

However, in the meantime sewage issues continue to be reported to us, the latest today is on the Downslink where it joins Snoxhall fields, adjacent to Hitherwood.

downs-link-thames-water-04-10-16-1

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If you have any information regarding sewage issues please do get in touch.

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