Solving your septic tank issues

Learn about the most common septic tank problems and the cost to fix them in this essential guide.

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With regular empties and maintenance, septic tanks are a practical waste drainage solution for many off-grid homes. However, when something goes wrong, you’ll want to act fast. If left untreated, septic tank problems can quickly become a serious health hazard.

This guide covers the most common septic tank problems homeowners face and how to fix them with the help of a professional to avoid being fined.

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First up, what happens if your septic tank is not draining?

Why is my septic tank not draining?

Is the wastewater from your showers, sinks, and toilets draining slower than normal or not draining away at all? This could mean the tank's drainage pipes are blocked, and therefore, your septic tank isn't draining correctly.

Strange gurgling sounds from the drain are another sign that your septic tank is not draining correctly.

You’ll want to hire a professional quickly to nip this in the bud. Otherwise, sewage and wastewater will start to back up, which nobody wants in their home.

A septic tank specialist will clear blocked pipes with jetting equipment, which costs an average of £300.

Why is my septic tank not working?

If your septic tank suddenly stops working, it might be because your pump or distribution box is blocked or there's a fault. These important components of the septic tank system distribute waste safely to the correct place.

A professionalmay use the same septic tank jetting equipment mentioned earlier to check if the pump or distribution box is blocked. But if that doesn’t work, you might need to replace the pump or distributor, each costing approximately £750.

While this is not ideal, it’s considerably cheaper than forking out for a new tank, which could cost £4,000.

Top tip: Though some septic tanks include a manufacturer’s warranty for basic protection, if your budget allows, add a septic tank warranty to your home insurance. It will cover parts of your septic system, such as the pump, if something goes wrong.

Why is my septic tank leaking?

A septic tank gradually leaking may be harder to spot. However, a pungent smell coming up from your drains or near the septic tank is a clear giveaway.

There are a few reasons why your septic tank might be leaking:

Crack or lid damage

The most obvious cause of a leak could be a tank crack or lid damage. Ground movement from building works or damage from tree or plant roots can sometimes cause this.

Provided it’s not beyond repair, a septic tank specialistshould be able to repair a crack for approximately £500. Meanwhile, replacing a septic tank lid is roughly£300.

A collapsed baffle

If there are no obvious cracks or other signs of damage, the leak might be caused by a collapsed baffle.

A baffle works by separating solid waste from wastewater within the tank. But if it isn’t doing its job, it might allow solid waste to leave the tank and enter the soakaway or drain field systems used for safely releasing wastewater into the ground. This can result in the soakaway becoming blocked and your septic tank leaking.

If your septic tank has a hanging baffle secured to the neck, a professional can repair the baffle for approximately £500.

What to do if your septic tank has overflowed

Wet, squishy patches of grass around your septic tank and drain field, along with a foul odour, all point to a septic tank overflow.

Reasons for a septic tank overflow could be:

You or the previous homeowners have not kept up with routine empties (typically once or twice per year)
You’ve moved into a new home with a larger family than lived there previously, and the tank is not big enough
Water levels have risen due to a period of heavy rain
The soakaway, which helps to remove wastewater safely, is blocked

First and foremost, contact a professional to examine if and why the tank is overflowing.

If you’re lucky, the overflow will not have contaminated the soakaway or surrounding drain field, and a septic tank professional will empty the tank as normal.

The average cost of emptying a septic tankvaries between £120 - £350, depending on the tank size.

It’s important to note that these prices are based on one call out for tanks up to 4,000 gallons and only include the pumping. Cleaning the unit is an additional cost.

However, if the overflow has contaminated the soakaway or drain field, this is a health hazard, and you’ll need a specialist contractor. That’s up next.

What to do if your drain field is contaminated

Thankfully, a contaminated drain field due to untreated sewage overflowing from a septic tank is less common. But if it does happen, this is a major health hazard, and you’ll need specialist help immediately. Your water source could be contaminated, making it unsafe for drinking and other uses.

First, stop using your water immediately to prevent further overflow. You’ll also want to stay well away from the contaminated area to keep you and your loved ones safe.

Next, call in a specialist contractor to excavate the space and remove the waste to ensure you comply with 2020 Government regulations. Failure to do this could land you with a fine from your local council or legal proceedings from the Environment Agency.

The cost to remove contaminated soil is approximately £40/m³.

How to find a septic tank specialist

Tinkering with your septic tank to fix a problem yourself is never a good idea. Not only is it unpleasant, but it could also invalidate the warranty on your septic tank or home insurance policy.

That’s why we always recommend hiring a septic tank specialist to fix any problems immediately.

They can also provide regular inspections to help reduce the risk of issues occurring again.

Use our search tool below to find a reputable professional and get a personalised quote.

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Septic tank problems: takeaways

Routine empties and regular maintenance are vital to avoid septic tank problems and costly repairs
If you have the right-sized tank for your home, it should only need emptying once or twice yearly
Don’t be tempted to repair a septic tank yourself. It could invalidate your home insurance or tank warranty
Make sure your septic tank and waste removal comply with the latest legislation
If you've moved into a new home with a septic tank, it's a good idea to have a septic tank inspection carried out

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