Off mains drainage

Buying or selling a house with a septic tank?

If you are buying or selling a property with a septic tank, sewage treatment plant or domestic pumping station you need to be aware of the risks involved.

There is a legal requirement for property sellers to inform buyers in writing if a property has a septic tank or small sewage treatment plant, including its location and maintenance requirements. This is usually done in the property information form exchanged during the conveyancing. Defects in the system are expected to be repaired either by the seller or the buyer as part of sale negotiation, in the same way that other defects in a property are dealt with. Many drainage surveys carried out by you conveyancer such as a CON29DW are brief and will not give you the information required. Check with your conveyancer or solicitor if you are unsure.

Septic tank fine

If you have a septic tank that discharges directly to a surface watercourse you will need to replace or upgrade your treatment system by 1 January 2020, or when you sell your property if before this date. Failure to do this can lead to prosecution by the Environment Agency under the The Environmental Permitting (England and Wales) (Amendment) (England) Regulations 2014. If a person is tried and convicted in a Magistrates Court, they could be fined up to £50,000 and/or sentenced to up to twelve months’ imprisonment. If they are tried and convicted in a Crown Court they could face an unlimited fine and/or be sentenced to up to five years’ imprisonment. In addition to this if you operate a septic tank or sewage treatment plant that is defective or not working correctly, Public Health will usually investigate complaints of nuisance from drainage systems. They can require the owner or owners to remedy the problem. Failure to do so can also result in legal action against the person responsible under The Public Health Act (PHA) 1961 or Section 17 The Building Act (BA) 1984 Section 59.

Septic tank pollution

What should you know?

As a seller or purchaser of a property with an off mains drainage system you must be able to answer the following questions:-

  • Do you have a septic tank, cesspit or sewage treatment plant?
  • Is the system registered?
  • What is the location of the treatment plant and drainage system?
  • Where is the discharge point?
  • Are there any third party land easements or wayleaves?
  • What is the capacity of the system?
  • What is the condition of the system?
  • How old is the system?
  • Have there been any changes made to the drainage system?
  • When was the system last maintained?
  • Are there any maintenance records?

With new septic systems being expensive to install, usually between £5,000 and £15,000, idyllic rural properties can quickly become expensive headaches. Further information can be found at

DJ Wilkinson offer FREE advice on off mains drainage systems such as septic tanks and sewage treatment plants. We can provide individuals, solicitors and conveyancers with basic or in depth reports answering the above questions.  Our reports also give recommendations, responsibilities and raise any concerns for property sellers or purchasers.

Do not get caught out! Find out more or Contact us today!



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