Acton storm tanks are a crucial part of making sure our sewer network can cope with heavy rain and prevent sewer flooding.
In 2015, we upgraded of some of our key equipment on site. We installed cleaning units and pump equipment, and made changes to how the storm tanks fill up and drain down to minimise the odour.
We also installed carbon filters on vented manhole covers to neutralise odour from the sewers.
This equipment and way of operating is working well and allows us to make sure each storm tank is used to its full capacity before another tank is filled, as well as ensuring the storm tanks drain down as soon as the levels in the local sewer have returned to normal.
Since January 2016, we have been monitoring odour levels at the site and we commissioned an independent odour survey to measure the odour levels in the summer. The findings from the survey assisted us in developing our odour mitigation plans for the site.
We are now in the process of installing covers to sit over storm tanks 3 and 4, which we are changing to fill first. Our covered tanks will include an odour control unit to treat the odorous air that sits between the storm water in the tank and the cover. We anticipate that all work will be complete by the end of February 2018.
Longer term options
Acton storm tanks currently play a crucial role in preventing sewer flooding to local homes when there is heavy rainfall.
Over the next few years, we will be looking at whether it we can change how the local sewer network operates to significantly reduce the frequency with which the storm tanks fill, or eliminate the need for the storm tanks when the connection to the Thames Tideway Tunnel and other proposed projects in the wider drainage catchment area are completed. We need to make sure that any changes do not increase the risk of sewer flooding to homes in other areas.
All future work we undertake needs to take into account the future operation of the site. Acton Pumping Station is a key site for the Thames Tideway Tunnel, and will lead to tanks 5 and 6 being decommissioned.
Once the Thames Tideway Tunnel is operational from 2023, the frequency with which the remaining 4 tanks are expected to fill will be reduced by 75% as the tunnel will fill first with storm flows.