Septic Tank Problem in Cambridgeshire

Building Contractors identified septic tank problems at this property in Cambridgeshire during renovation works. The building contractors recommended the homeowner contact Mantair regarding the septic tank problems.


From our site investigations it was evident that the septic tank problems were being caused due to the soakaway connected to the tank failing. As a result of the soakaway failure the septic tank was flooding, causing the foul drainage from the property to surcharge. The septic tank cover slab also had high levels of sulphate corrosion.

On viewing the Ordnance Survey Geological Map for this area of Cambridgeshire it was evident that the sub-strata was permeable. In view of this and the access restrictions at the property, Mantair engineers recommended upgrading the existing septic tank with a Mantair conversion unit and the construction of a new ‘high level’ soakaway / drainage field. It was also agreed that a new concrete cover slab should be constructed to make the septic tank structurally sound. It was necessary for Mantair engineers to carry out Percolation Tests to determine the porosity of the sub-strata and to obtain the size of soakaway / drainage field required.


Stage 1 – Removal of of the septic tank concrete cover slab and installation of the Mantair conversion unit.


Stage 2 – Construction of the new high level soakaway / drainage field.


Stage 3 – Construction of the new septic tank top and associated ancillary works.

One of the key benefits with installing a Mantair septic tank conversion unit is that it fits within the existing tank removing the need for a new tank to be installed.

Mantair provides a comprehensive septic tank and sewage treatment plant service throughout Cambridgeshire and other surrouding. This includes free site inspections, guidance and advice on the most suitable system for the client’s requirements, complete installation, commissioning and full after sales care.

Did you know that the cost to resolve your septic tank problems may be covered by your existing buildings insurance policy?

Mantair works in partnership with the UK’s leading drainage insurance claims management company to offer our customers a unique insurance claims management service. Providing expertise in managing insurance claims for the costs of repairing or replacing damaged drainage systems, we work on behalf of property owners helping them to save thousands of pounds in resolving their septic tank problems. Read more

Call our team today to find out more about how we can help solve your septic tank problems.  01255 853890.


Sewage Treatment Plant Installation Arrington, Cambridgeshire.

Located on the delightful Wimpole Estate in South Cambridgeshire is Rectory Bungalow.  After the renovation of the property in 2012, Mantair were appointed by the National Trust as the preferred contractor to provide a design, installation and commissioning service for the upgrading of an ageing septic tank serving the property.

Survey & Design

On viewing the drainage layout of the property it was found that the existing septic tank was located close to a willow tree.  On inspection of the septic tank it was found that the tank had substantial root ingress which had resulted in the structural integrity of the tank being impaired.  It was therefore necessary to provide a sewage treatment solution that would require the installation of a new tank.

A detailed survey was carried which included a Percolation Test.  The results of the Percolation Test showed that the sub-strata was impermeable and that a replacement septic tank soakaway system would not operate effectively.

After considering all the various options for foul drainage disposal and the size of the property, Mantair recommended the installation of six person sewage treatment plant with a discharge direct to a nearby watercourse.  It was important that the chosen sewage treatment sewage treatment plant was installed below ground to ensure there was no visual impact on the properties surroundings.

As part of the project Mantair liaised with the Environment Agency and the local Building Control Department to obtain the relevant approvals for the installation and the discharge to the nearby watercourse.


Prior to any ancillary works commencing Mantair engineers scanned the proposed location of the new sewage treatment plant and areas where any excavations were taking place to ensure that no underground services were present.


The scope of the installation works included:

  • Exposing the existing foul drainage pipe work and diverting to the location of the new sewage treatment plant;
  • Installation of the sewage treatment plant in a suitably sized excavation, including for a concrete base and backfill;
  • Provision of an RCD protected power supply to the sewage treatment plant installation;
  • Installation of a new 110mm diameter discharge drain to the boundary ditch;
  • De-commissioning of the failed septic tank;
  • Backfilling all excavations and leaving the area neat and tidy.

On completion of the ancillary works Mantair commissioned the new sewage treatment plant, including setting of air valves, checking all pipe work joints and viewing the discharge into the final discharge chamber.

All machinery was removed from site with the garden being left in a neat and tidy manner.

If you require assistance with a septic tank problem in Cambridgeshire or have a requirement for a new sewage treatment plant or septic tank, call our team today to receive a free site visit on 01255 853890.