When is it time to empty the septic tank?

It depends on how often it needs to be emptied

There is no fixed date for all septic tanks. Two properties with the same type of septic tank may require very different emptying schedules depending on these factors.

The size of the grave and the number of people

The more people use the septic tank in relation to its capacity, the sooner it fills with sludge. A small septic tank in a house with many occupants needs to be emptied more frequently. We explain how these factors relate to calculating the optimal size of a septic tank based on the number of users.

The type of use of the property

A main residence is not the same as a second home that is only used in the summer, or a holiday let that is full of people during the season. In the latter cases, usage is concentrated over just a few months and the septic tank is subjected to a heavy load all at once.

What ends up in the pit

Wipes, oil, food scraps and excess chemicals cause the septic tank to fill up more quickly: either they do not break down, or they harm the bacteria that break down the sludge. Here is a list of items that should never be put into the septic tank.

The condition of the pit

An old septic tank, with damaged partitions or broken baffles, is less effective at separating solids and is more likely to cause problems sooner, even if it is not full.

How often should you have your septic tank emptied, depending on your circumstances?

A rough guide within the usual range of 1 to 3 years. The exact frequency of your septic tank maintenance is determined by a check of the sludge level.

Your case	Approximate frequency	Why
A main residence with too many people for the size of the pit	Just under a year	A heavy daily workload
Principal residence with a balanced use	Between 1 and 3 years, depending on the review	Constant, moderate load
A second home that is used for just a few weeks a year	Just under 3 years	Low total load
Holiday rental property	Check the level before the peak season	A heavy workload concentrated into just a few months
A pit showing signs of saturation	Now	It’s already full or not working properly

Signs of a full septic tank

If you notice any of these signs, don’t wait until it’s due according to the schedule: it’s best to arrange for the oil to be changed and the engine to be serviced.

• Persistent odours in the house, in the drains or around the septic tank.
• Slow-draining pipes in several places in the house at the same time.
• Gurgling noises in the pipes or in the toilet when you flush.
• Dirty water is backing up through the lowest drains in the house.
• Puddles or damp ground over the pit or the infiltration area, even though it hasn’t rained.

If the water is already overflowing, it’s an emergency: we explain what to do if there are signs that your septic tank needs urgent cleaning. There are also more subtle warning signs, which we go through in ‘Less obvious signs that your septic tank needs checking’, along with what happens if you ignore them – what happens if you don’t empty your septic tank.

How to tell when it’s time to clean out your septic tank without waiting for the signs

By the time the signs appear, the septic tank has already been full for some time. To stay one step ahead, there are two simple tools.

Keep a record of the castings

Make a note of the date of each emptying and what the technician tells you about the condition of the septic tank. Once you’ve recorded two or three emptying dates, you’ll know how often yours fills up, which is the best possible guide.

Request a review of the level

A professional can open the manhole and check how much space is taken up by the sludge at the bottom and the scum on the surface. If there is little space left for water, it is time to empty the tank, even if there are no obvious signs of a problem. We explain what these layers are, what a septic tank is and how it works.

Do not open the pit yourself: gases can build up inside it, which may be dangerous; that is why it is important for the pit to be well ventilated and for it to be inspected by someone with experience.

What is involved in a professional septic tank clearance?

Emptying a septic tank isn’t just a matter of removing the water: you have to extract the sludge from the bottom, clean the inside and dispose of the waste in accordance with the law, as it is classified as hazardous waste.

At Limpiezas Domingo e Hijos, septic tank emptying includes:

• Sludge extraction using a tanker lorry, with vacuum systems operating at several bars of pressure.
• Internal cleaning using pressurised water where necessary, to break down solids, sludge and adhering residues.
• Basic inspection of the condition of the pit, with maintenance recommendations.
• Waste management in accordance with current regulations.

If, whilst emptying the septic tank, we detect a problem with the pipes or manholes leading to it, we can inspect them and pinpoint the source of the problem. We’ll explain the step-by-step process of emptying a septic tank and the factors that influence the cost of doing so.

We provide our service in the Marina Alta, the Marina Baja and La Safor.

Plan your waste disposal before it becomes necessary

A scheduled drain clearance is more convenient than an emergency one and prevents problems at the worst possible moment. Here are a few tips on choosing the right time:

• Before the summer or a period of heavy use, particularly in second homes and holiday let properties, where the septic tank is subjected to a heavy load over a few weeks.
• Before leaving your home unoccupied for a while, to avoid finding unpleasant odours or faults when you return. We explain this in ‘How to plan the emptying of your septic tank before going on holiday’ and ‘How to prepare your septic tank before leaving your home unoccupied’.
• With a maintenance plan that schedules emptying based on the actual usage of the septic tank, preventing it from becoming overloaded and avoiding emergencies. Ask us about it when you request a quote.

Frequently asked questions about when to empty a septic tank

Do you need to empty the septic tank of a house that is hardly ever used?

Yes, although less frequently. Sludge still builds up with every use, and after long periods when the house has been unoccupied, it is advisable to check the condition of the septic tank before resuming normal use.

Is it possible to have your septic tank emptied too often?

It doesn’t usually cause problems with the septic tank, but it means paying for a service that wasn’t yet necessary. That’s why it’s a good idea to check the sludge level and keep a record: that way, it gets emptied when it needs to be.

Do products containing bacteria mean you don’t have to empty the septic tank?

No. They can help break down organic matter, but they do not remove the sludge that accumulates at the bottom. The septic tank still needs to be emptied regularly.

If there are puddles on top of the pit after it has rained, is it full?

Not necessarily. After heavy rain, the ground may be waterlogged. If puddles or damp patches remain even when the weather is dry, this may indicate that the septic tank or infiltration area is not draining properly.

What happens to the waste that is removed from the pit?

It is hazardous waste, so it cannot be disposed of just anywhere. It is transported and managed in accordance with current regulations, following specific environmental procedures.

Empty the septic tank before you’re notified

Most septic tanks need to be emptied every 1 to 3 years, depending on their size and usage. Keeping a record and checking the sludge level will tell you when it’s time to have yours emptied; and if you notice any odours, slow drainage, gurgling or overflows, don’t wait.

At Limpiezas Domingo e Hijos, we empty septic tanks using a tanker lorry in the Marina Alta, Marina Baja and La Safor regions, with over 15 years’ experience and waste management in accordance with regulations.

Call us on 672 450 224 or 966 447 070, or request a quote.