Mogden reports and publications

Boundary odour monitor readings

There are 13 odour monitors at Mogden which measure levels of hydrogen sulphide, which is one of the compounds that make up odour at sewage treatment works.

The charts below provide a breakdown of weekly odour monitor readings taken throughout the year.

London Borough of Hounslow site inspections

We work very closely with the London Borough of Hounslow's pollution control department to reduce odour from Mogden.

The local Environmental Health Officer is welcome to carry out a site visit whenever they wish.

Following each visit, any observations are sent to the management team at Mogden for review and, when necessary, appropriate actions are taken.

These observations and actions are documented in a joint report, and can be viewed by clicking the links below.

Storm flows from Mogden STW

When it rains, the high volume of wastewater coming into Mogden cannot be all treated at once and so, the excess is stored in storm tanks after first being screened and de-gritted. Once the flow reduces, the wastewater is returned to the head of the works for processing.

If the storm tanks fill up before this happens, however, we have no option but to send the excess wastewater to the River Thames to prevent it backing up into streets or homes.

The charts below provide a record of when partially treated wastewater has been discharged to the river.

The data below will tell you when high flows have meant that uncovered storm tanks have been used.

17 October 2014 – This data was provided for the London Borough of Hounslow Housing and Environment Scrutiny Panel meeting on 13 October 2013.