How do you inspect your sewer line

Leak test of sewer pipes: compulsory or rip-off?

Perhaps you have already experienced the following situation: The doorbell rings and a man stands at the door who comes straight to the point. How about the sewer pipes on your own property? Because of tightness? Concerned expression, questioning look. And then there is an indication of the dangers and costs of leaky pipes: the environment. High fines. And after all, one is obliged to subject the sewage pipes to a leak test every 20 years.

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Most homeowners are now getting nervous. What about the legal regulations? Is a leak test compulsory or voluntary? What are the deadlines, what does it all cost?

Legal regulations for leak testing of sewage pipes

First of all: do not get involved in door-to-door sales. When it comes to leak testing, there are often scare tactics and many half-truths involved.

The Water Resources Act

The fact is that there are two legal frameworks. On the one hand there is the Water Resources Act (WHG). Paragraph 60 states that "wastewater systems must be built, operated and maintained in accordance with the generally recognized rules of technology". And § 61 stipulates: Everyone who "operates a wastewater system is obliged to monitor its condition, functionality, maintenance and operation as well as the type and quantity of wastewater and wastewater constituents."

In practice, however, that means first of all - nothing. The law does not provide for precise deadlines or specific requirements as to when and how this test must take place.

The DIN 1986-30

So what deadlines have to be observed when monitoring wastewater systems? This is regulated by DIN 1986-30, "Drainage systems for buildings and properties - maintenance". And this is where most of the misunderstandings - or also deliberate false statements - arise.

Originally, this DIN standard provided for an initial test of existing basic lines by December 31, 2015. This deadline has been deleted and replaced by a so-called "time span rule". And in this same period of time regulation, a test of the domestic sewage pipe is recommended every 20 years, in new systems with a verifiable leak test after 30 years. This is where the argument often cited by front door representatives comes from: "You have to have your sewers checked after 20 years". Alone - it's not true.

Regulation by federal states and municipalities

The DIN 1986-30 is not legally binding. In practice it is simply the case that the federal states, sometimes even the cities and municipalities, regulate when a leak test has to be carried out. And there the regulations are completely different.

In Baden-Württemberg, for example, private, domestic wastewater systems are exempt from an inspection requirement if no more than eight cubic meters of wastewater occur per day. In Mecklenburg-Western Pomerania, too, private households are not required to perform a leak test.

In contrast, there are clear guidelines in Schleswig-Holstein. The state has stipulated "that the property drainage systems in the areas in which the public waste and mixed water sewers have already been rehabilitated or will be rehabilitated by December 31, 2022, must be checked for leaks by December 31, 2025". If the renovation is not completed until after 2022 (and everything indicates that), a leak test will be required within three years. The only question left for the homeowner in Schleswig-Holstein is: How do I find out when the renovation of "my" public sewer and mixed water sewer is complete?

In contrast, the leak test in Hamburg must be carried out by the homeowner by the end of 2020. But don't panic: it is enough if you can prove that you have arranged an examination date. That can also be in 2021. So there is no reason to act hastily. And as I said, NEVER engage in door-to-door sales. You can find all information about leak testing in Hamburg here.

Other regulations in water protection areas and for new buildings

It gets even more complicated when the house is in a water conservation area. Then, as a rule, completely different deadlines apply. They are usually much stricter, but also not regulated in a uniform manner.

The same applies to new buildings. Builders should clarify in good time whether the municipality also requires corresponding leak tests for new drainage connections and who is allowed to issue them. It is best to include the required tests in the building contract.

General statements regarding leak testing of sewage pipes are as good as impossible. If you want to be on the safe side, you should check with your local authority or city council for local regulations.

Test procedures: what are there, who is allowed to do them?

Different inspection deadlines and intervals, that alone causes a lot of confusion. In addition, the scope and evidence of the leak test is regulated differently everywhere. Here, too, the cities and municipalities would be the first point of contact.

What is precisely determined by the aforementioned DIN 1986-30, however, are the test procedures themselves and the technical requirements for them.

Test method for domestic sewers

  • The optical inspection (TV inspection) of the lines with the help of a special camera is the standard test for existing lines.
  • In the simplified leak test (DR2) the pipe is completely filled with water. If the water level drops, water is refilled. If the amount of water topped up is within a tolerance, the line is considered leakproof. The whole procedure takes around 15 minutes.
  • In the Leak test with water or air (DR1) the line is filled with water or air. If the sewer pipe can keep the required water level (usually up to the top of the ground) or the air pressure within a tolerance, it is considered leakproof.

Whichever test method is used, it should only be carried out by knowledgeable specialists with the appropriate technical equipment. At least that is what the DIN standard provides. But who is really knowledgeable?

As a rule, the plumber you trust should have such expertise and the equipment. If in doubt, get confirmation before each exam that you are dealing with a specialist who is expressly qualified for such work. And again: Under no circumstances should you arrange such an (alleged) service at the front door.

According to the trade journal "SBZ - Sanitär, Heiz, Klima" a visual inspection also includes a list of the damage and an assessment with regard to a possible renovation. The results of the leak test by optical inspection must be recorded in a protocol and clearly assigned to the line sections.

What does a leak test cost?

The costs of course depend heavily on the size of the property and the duration of the test. As a rule, you have to reckon with around 300 to 500 euros.

In order to save time (and money), check the access to the sewer system before the test date and make it accessible if necessary. And talk to your neighbor before the exam. Maybe he has already planned to do this and you can negotiate a discount. By the way: The cost of the leak test can be deducted from the tax on a pro rata basis.

What to do if the sewer pipe is leaking

First of all, nothing at all. The house owner cannot avoid renovation because he is responsible for maintenance. As with every renovation task around the house, it is also important here: Obtain several offers, compare them and only then decide. Refurbishment can be expensive, but it doesn't necessarily have to be. The costs depend heavily on the degree of damage and the appropriate remedial measures. That is why it is so important to obtain several independent offers from specialist companies.

Conclusion: have a leak test carried out or not?

The fact is: Every house owner is responsible for the maintenance of his sewer pipes. Whether and if so, when this is absolutely necessary, you can only find out bindingly from your local or city administration.

There could be other reasons for a leak test as well. On the one hand, it also serves to maintain the value of the building and property and could be an additional argument when selling. And if you want to be insured against possible damage to the sewer pipes, the building insurance usually requires a leak test beforehand.

In general, the following applies:

  • Only ask the local administration whether a leak test is even required for you.
  • NEVER engage in door-to-door sales, under no circumstances act under time pressure.
  • Only commission certified specialist companies. The best thing to do is to get various offers from local companies.

Most of you will not have any real reason to act. So if the doorbell rings soon and a concerned "specialist" asks about the condition of your sewer pipes - then just close the door.

Do you want to prevent the water from the sewer pipes from flowing back into your house during heavy rain? In this case, a backwater flap is the most important protection against flooding.