Does a Seller Have to Provide a Septic Tank Survey When Selling a House?

What Does a Seller Have to Provide?

If a property relies on a septic tank or small sewage treatment plant, the Environment Agency’s General Binding Rules place responsibilities on the person operating the system.

When that property is sold, the existing operator must tell the new operator in writing that a sewage discharge is in place.

The information passed to the buyer should include:

• A description of the treatment system and drainage system
• The location of the main parts of the system
• The location of the discharge point
• Details of changes or alterations made to the system
• Information about how the system should be maintained
• The manufacturer’s maintenance manual, where available
• Maintenance records, where available

This means that private drainage should not simply be treated as an unidentified tank somewhere in the garden. The buyer needs enough information to understand the system they will become responsible for.

You can read more about these responsibilities in our guide to General Binding Rules and property sales.

So Is a Septic Tank Survey a Legal Requirement When Selling?

No. There is no general rule saying that every seller must obtain a septic tank survey before putting a property on the market.

That is different from saying that the condition and compliance of the drainage system do not matter.

A seller may know that the property has a septic tank, but still be unable to answer important questions such as:

• What condition is the tank actually in?
• Where does the effluent discharge?
• Is there a drainage field and where is it located?
• Does the system appear to comply with the General Binding Rules?
• Has the drainage field started to fail?
• Is the system large enough for the property?
• Will repair or upgrading work be required?

This is where a specialist off-mains drainage or septic tank survey becomes valuable.

Why Might a Seller Arrange a Survey Before the Buyer Does?

There can be a significant advantage in discovering a private drainage problem before a sale is approaching exchange of contracts.

If the buyer’s survey identifies an issue late in the transaction, everyone suddenly has to establish what is wrong, what it will cost to correct and who is going to pay for the work.

That can result in:

• Further investigations
• Requests for quotations
• Renegotiation of the purchase price
• Delays to exchange or completion
• Discussions between solicitors about responsibility
• In serious cases, a buyer reconsidering the purchase

Finding the same issue earlier gives the seller much more time to understand the problem and decide how it should be dealt with.

A pre-sale inspection is therefore not simply about proving that everything is compliant. It is about replacing uncertainty with useful information.

What Do the General Binding Rules Say About Septic Tanks?

The General Binding Rules govern small sewage discharges from septic tanks and small sewage treatment plants in England.

Where the applicable rules are met, the system can normally operate without an individual environmental permit.

Among other requirements, the system must be appropriately maintained, must not cause pollution and must use an appropriate method of treatment and discharge.

One of the most important issues during property sales concerns septic tanks that discharge directly to surface water.

Can a Septic Tank Discharge Into a Stream or Ditch?

A septic tank must not discharge directly into a watercourse such as a river or stream.

If an existing septic tank does discharge directly to surface water, the Environment Agency says the operator must take action. Depending on the circumstances, this may involve:

• Connecting to a public foul sewer
• Replacing the septic tank with a suitable small sewage treatment plant
• Installing an appropriate drainage field and changing the discharge to ground

Where a property with this type of non-compliant discharge is being bought or sold, the Environment Agency advises the buyer and seller to agree who will be responsible for upgrading or replacing the system and to make that agreement a condition of the sale.

This is exactly the kind of issue that is better discovered before the transaction reaches its final stages.

Does a Septic Tank Survey Check General Binding Rules Compliance?

A specialist private drainage survey can help establish whether the system appears to meet the relevant requirements and identify areas that need further attention.

An inspection may consider:

• The type of private drainage system installed
• The apparent condition of the tank or treatment plant
• Inlet and outlet arrangements
• The location and condition of visible drainage components
• The drainage field or other discharge arrangement
• Signs of leakage, blockage or system failure
• Where wastewater ultimately discharges
• Whether further investigation, repair or upgrading may be necessary

This is why a private drainage survey is useful during a property transaction. It does considerably more than establish whether there happens to be a septic tank on the site.

For a detailed explanation, see what a septic tank compliance inspection actually checks.

Does the Buyer Need Their Own Septic Tank Survey?

A buyer is not obliged by the General Binding Rules to commission a survey simply because they are purchasing a property with private drainage.

However, the buyer will normally become responsible for the system after purchasing the property. It therefore makes sense to understand what is being acquired before exchange.

A normal building survey may identify that private drainage exists, but it is not the same as a specialist inspection of the septic tank, sewage treatment plant, drainage field and discharge arrangements.

If important information is missing, the maintenance history is unclear or there is uncertainty about the discharge, a specialist survey can provide information that a conventional property survey may not.

Who Is Responsible If the Septic Tank Is Non-Compliant?

While the property remains with the seller, the existing operator remains responsible for meeting the rules applying to the system.

Once ownership and responsibility transfer, the buyer may become the new operator and inherit the ongoing responsibility for maintaining and operating the private drainage system correctly.

That does not necessarily mean that the seller must personally complete every piece of upgrading work before a property can be sold.

Where work is required, responsibility can sometimes form part of the negotiation between buyer and seller. What matters is that the issue is understood and dealt with clearly rather than being unknowingly transferred with the property.

What Should Sellers Do Before Putting a Property on the Market?

If you are selling a property with private drainage, it is sensible to gather as much information as possible before the conveyancing process gets under way.

Useful information includes:

• The type and approximate age of the system
• Its location
• The location of the drainage field or discharge point
• Emptying and servicing records
• Installation or repair documentation
• Manufacturer information
• Details of any previous problems

If these questions cannot be answered confidently, or if there is uncertainty about the condition or compliance of the installation, this is a good point to consider a specialist inspection rather than waiting for the buyer to raise the issue.

What Should Buyers Ask Before Purchasing a House With a Septic Tank?

Buyers should establish exactly what drainage system they will become responsible for.

Useful questions include:

• Is it a septic tank, sewage treatment plant or cesspit?
• Where is it located?
• Where does it discharge?
• When was it last emptied or serviced?
• Are maintenance records available?
• Has it ever needed significant repairs?
• Is the system shared with another property?
• Has its compliance with the General Binding Rules been checked?

Where those answers are incomplete, a homebuyer septic tank survey can help provide a much clearer picture.

The Bottom Line

A seller does not automatically have to commission a septic tank survey simply because a property has private drainage.

What the seller must do is provide the new operator with the required written information about the sewage treatment and drainage system.

In practice, however, neither buyers nor sellers benefit from discovering a drainage or compliance problem at the last minute.

A specialist survey can establish what system is present, assess its condition and discharge arrangements, identify possible General Binding Rules issues and provide a clearer basis for any work or negotiation that may be required.

If you are buying or selling a property with a septic tank, sewage treatment plant or other private drainage system, Boxall Ward can carry out a specialist inspection and provide clear advice on the condition and compliance of the system.

Call 01903 815377 or contact Boxall Ward to discuss a private drainage survey.

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