Case Study

Cheaper isn't always better:  How Evolution Drains fixed this drainage disaster...


Evolution drains were called in to sort out a fairly new sewage treatment plant, which wasn't working properly, despite the fact it had only been installed a few years previously. Unfortunately, the original installer had gone out of business.


On close analysis, it became apparent that the tank wall had been cracked during the original installation. This had allowed concrete into the bottom of the tank, which had then solidified, preventing the transfer of liquids from one chamber to another. Not only this, but the pump had been set at such a level that it would only pump out when all the foul inlet pipes were backed up. Unsurprisingly this had caused almost continuous issues with both the pipes and the outflow - which didn't meet legal standards as it wasn't being properly treated.



1. To assess what was wrong with the tank we completely emptied it and inspected the interior in detail. Having established the crack in the tank wall and the concrete in the base, the only snesible solution was to dig out and replace the tank.



2. We excavated around the tank, which involved digging out the concrete that encased it, and cut away the plastic . The original tank was also too small for the house feeding it, so the hole we dug had to be bigger to accommodate a larger tank.



3. Having excavated and removed the original tank, we were then able to place the new tank into the space. We then modified the existing pipework so that there was the proper fall, and reconnected everything. The house was only without service for about 6 hours.



4. We took away the debris, and left the site neat and ready for reseeding. Now, we think you'll agree that it would have been a lot more cost effective to have had this job done properly the first time. Beware the cowboys and the quotes that are too good to be true - no one wants to have to pay for this sort of job twice.

Where we work


We work to provide our sewage and effluent treatment systems across the South of England, including the following counties:


  • Gloucestershire
  • Herefordshire
  • Devon
  • Oxfordshire
  • The New Forest National Park
  • Dorset
  • Hampshire
  • Somerset
  • Avon
  • Cornwall
  • Wiltshire


Please do not hesitate to get in touch to find out if we work in your area.