The problem of misconnections

Misconnections are a widespread problem for many water companies. They occur when water drains are wrongly connected, directing surface or foul water into the wrong sewer system.

Misconnections can lead to problems such as the flooding of sewage treatment works during heavy rain and foul water from domestic appliances flowing into rivers and streams.

As the locations of many misconnections are unknown, APEM has developed a unique and cost-effective method for mapping them. This allows water companies to find and quantify the problem in their region.

Identifying misconnections with aerial surveys

Aerial view of London docks and city airport

We use ultra-high resolution cameras fitted to specialist survey aircraft to carry out aerial photographic surveys of towns and cities. Analysis of the photographs by our expert team allows us to identify and geotag any buildings with misconnected pipework, such as foul-to-surface or surface-to-foul drains.

The surveys are extremely quick and cost-effective – a town of 100,000 homes can be captured in around two to three hours. The data from the surveys can then be used to target the misconnected homes for leaflet drops and visits by ground teams, thereby improving efficiency.

Homeowners can then be encouraged to fix the misconnected pipes, reducing pollution to local streams and coasts.

  • Misconnected drains on domestic properties
  • Misconnected drains on domestic properties
  • Misconnected drains on domestic properties

Example – an English coastal town

  • Coastal water pollution continued despite upgrades to water company assets.
  • About 95 per cent of homes are on separated sewer network.
  • 100,000 properties were surveyed and more than 16,000 images collected.
  • 6,000 misconnections were identified and mapped across the survey area.
  • The survey cost less than 50p per household.

If you have any queries, please contact David Campbell, associate director.
Alternatively you can email us here. Or call 0161 442 8938.