Septic Tank Rules in Lincolnshire: What Every Homeowner Needs to Know in 2026

Lincolnshire has more properties on private drainage systems than almost any other county in England. If you own a rural home, farmhouse or converted barn, there's a strong chance you're relying on a septic tank or sewage treatment plant rather than mains sewerage — and there are rules you need to follow.

The regulations changed significantly in 2020, and many Lincolnshire homeowners are still unaware that their existing system may now be illegal. Here's what you need to know.

What Are the General Binding Rules?

The General Binding Rules (GBRs) are Environment Agency regulations that govern how small sewage discharges from domestic properties must be managed. They apply to septic tanks, cesspits, and small sewage treatment plants across England — including all of Lincolnshire.

The key update that came into force in January 2020 is this: septic tanks that discharge directly to surface water are now banned.

What Counts as Surface Water?

Surface water includes:

• Rivers, streams and becks
• Ditches and drains (including Lincolnshire's extensive network of agricultural drains)
• Ponds, lakes and reservoirs
• Any other watercourse

This is particularly relevant in Lincolnshire, where many older rural properties have septic tanks that discharge into field drains or the county's vast network of drainage ditches. If your tank does this, it is almost certainly non-compliant under current rules.

What Are You Required to Do?

Under the General Binding Rules, you must:

• Ensure your septic tank or treatment plant discharges to ground (via a soakaway or drain field) — not to surface water
• Have your system desludged regularly by a licensed waste carrier
• Keep records of maintenance and emptying
• Not cause pollution to controlled waters

If your system discharges to surface water, you must either:

• Divert the discharge to a suitable soakaway or drain field, or
• Replace the septic tank with a full sewage treatment plant (which can discharge to surface water under a separate permit)

Does This Affect Property Sales in Lincolnshire?

Yes — significantly. Since 2020, solicitors and surveyors routinely check septic tank compliance during property transactions. A non-compliant system can:

• Delay or block a sale
• Reduce the sale price
• Require the seller to carry out remedial works before exchange
• Expose the buyer to enforcement action if they proceed without addressing the issue

If you're buying or selling a rural Lincolnshire property with a private drainage system, a pre-purchase septic tank survey is essential.

What Are the Consequences of Non-Compliance?

The Environment Agency takes non-compliance seriously. Consequences can include:

• An enforcement notice requiring you to upgrade the system
• Prosecution and fines of up to £50,000
• A civil sanction (fine) issued without prosecution
• Liability for any clean-up costs if your discharge causes pollution

With Lincolnshire's rivers and drains under increasing pressure from agricultural runoff, the EA is actively enforcing these rules — particularly in ecologically sensitive areas like the Lincolnshire Wolds AONB and around the Broads drainage network.

How Do You Know if Your System Is Compliant?

If you're not sure where your tank discharges to, the safest approach is to have a compliance survey carried out. We can inspect your system, locate the outlet, and advise whether you're compliant — or what needs to change.

In many cases, upgrading is more straightforward than homeowners expect. Installing a new soakaway or upgrading to a treatment plant can often be done without planning permission under Permitted Development Rights, though this should always be confirmed for your specific property.

What About Cesspits?

A cesspit is different from a septic tank — it's a sealed tank that doesn't discharge anywhere. Cesspits don't fall under the same surface water discharge rules, but they do need regular emptying (usually every 6–12 weeks depending on usage) and must not leak. If your cesspit is overflowing or leaking, that is an environmental offence regardless of the GBRs.

Regular Maintenance Still Matters

Even if your system is fully compliant, the GBRs require you to maintain it properly. This means:

• Annual desludging by an EA-licensed waste carrier
• Keeping records of every empty and any maintenance work
• Not using products that kill the bacteria your tank relies on
• Protecting the drain field — no vehicles, no deep-rooted plants