Property Drainage; Leak Test

Like any other structure, a sewer system is subject to a natural aging process. It is therefore necessary to have the condition of the sewer system inspected at regular intervals. Leaking sewer pipes have an impact on the environment: Leaking wastewater can contaminate the soil and groundwater.

All components of the property drainage system (pipes, manholes, separators, etc.) connected to the public sewer system that are buried in the ground or located under buildings must be inspected. The same applies to the service connections on public property and the connection to the public sewer.

Refer to the approved site drainage plans in your construction documents and familiarize yourself with your drainage system before the inspection. You can use these plans to request quotes from specialized companies. If these are not available, you can usually request a copy (scan) of the plans from the Erlangen City Archives. It is also recommended that you locate the inspection chambers and cleaning access points in the building in advance and ensure they are accessible.

Specialized companies should be commissioned to conduct the inspection. These companies should:

• Either hold the “D” quality seal for sewer construction for the respective scope of testing, or

• hold a current certificate of competence from the DWA (German
Association for Water Management, Wastewater, and Waste e.V.) or

• hold a current certificate of qualification for conducting leak tests issued by the V.D.R.K. (Association
of Pipe and Sewer Technology Companies e.V.)

You can find qualified contractors here: List of Qualified Contractors. Unfortunately, companies without proof of qualification cannot be recognized. Caution: Do not agree to door-to-door sales; instead, always request a written quote from reputable specialized companies.

After preliminary cleaning via high-pressure flushing, the inspection is conducted using a camera inspection. The inspection typically begins at an access manhole located on the property. A pressure test (filling with water) is generally only necessary if no pressure test was performed during the construction of the system or if the camera inspection is deemed insufficient to verify the system’s watertightness.

In some cases, it may be necessary to retrofit cleaning access points or an inspection chamber in order to perform the inspection. Please note that if significant changes are made to the sewer system (e.g., rerouting of pipes, installation of an inspection chamber, etc.), a drainage permit must be obtained from the Building Inspection Office of the City of Erlangen well in advance of the start of construction.

By placing sealing bubbles over inspection chambers or cleaning openings, the sewer lines throughout the entire private sewer system can be tested for leaks.
During a water pressure test, the test medium must reach a level at least up to the backflow level (definition: street level at the connection point to the public sewer system). Fifteen minutes after filling with water (settling period), water loss during the following 15 minutes (test period) must not be ≥ 0.2 l/m² of the wetted inner surface area of the pipes and manholes.
When testing individual manholes, the water loss within 15 minutes must not exceed 0.4 l/m² of the wetted interior surface area of the manhole. In the air pressure test procedure, the pipe ends are sealed, and the sewer is pressurized to a test pressure equivalent to the pressure head of the water fill. The test is considered passed if the permissible pressure drop values are met.
If testing the property’s drainage system is not possible due to a lack of inspection chambers, a cleaning opening or an inspection chamber must be installed at a later date. Please note that in the event of significant changes to the wastewater system (e.g., rerouting of pipes, installation of an inspection chamber, etc.), a drainage permit must be obtained from the City of Erlangen’s Building Inspection Office well in advance of the start of construction.
If damage to the sewer has already been detected during a prior camera inspection, the pressure test may be waived. In that case, the repair work must be initiated immediately.

There are now a number of repair options available that can restore the sewer’s watertightness without having to dig up the pipe (e.g., renovation using the pipe lining method). For older pipes located beneath the foundation slab, it must be determined whether the pipe can be decommissioned or rerouted. In such cases, permission must be obtained on a case-by-case basis from the Building Authority of the City of Erlangen. Once the rehabilitation is complete, another condition inspection and leak test are conducted.

The inspection results must be submitted in full by the specified date, along with the inspection report and drainage plan, listing all inspected system components. The inspection results must also be submitted in the event of damage.

A leak test conducted during the construction of the property drainage system counts as initial proof of leak-tightness. If the property drainage system was not tested during construction, a test must be performed immediately.
The inspection intervals depend on the type of wastewater discharged and the location of the property:

For domestic wastewater, the following applies:

• The initial proof had to be provided by December 31, 2015, at the latest, and thereafter every 20 years via camera inspection.
• Inspections (pressure tests) of new buildings using a pre-existing connection sewer are valid for 20 years.
• Inspections (pressure tests) of new buildings with a newly constructed connection sewer are valid for 30 years.

Pressure tests conducted on new or existing buildings located in a water protection area are valid for 5 years. In cases where an exemption applies, a pressure test must be performed every 10 years. A request to extend the testing interval may be submitted in conjunction with a renovation or replacement of the pipeline.

Important Note:

Please note the inspection date applicable to your property. Failure to comply with the inspection requirement constitutes an administrative offense subject to a fine under the Drainage Ordinance (EWS).

Pursuant to Section 12(1)(2) of the Drainage Ordinance (EWS), sewers and structures used to discharge domestic wastewater that lacked proof of watertightness were required to be inspected for the first time by December 31, 2015. The property owner is responsible for arranging the condition inspection. The Water Protection Area Ordinance also applies to the inspection requirement in the Erlangen-West water protection area.

Rainwater pipes connected to a public storm sewer in a separate system and domestic wastewater pipes located inside the building (connecting pipes from plumbing fixtures, downspouts, visible collection pipes) are not initially subject to any mandatory periodic inspection. For structural reasons, stormwater pipes located below the foundation slab should undergo a visual inspection.

Discharges of external water are generally not permitted. In the event of sewer backup, wastewater can contaminate the soil and water bodies. Existing drainage systems must therefore be isolated.

If a drainage system is demonstrably necessary, the next steps must be coordinated with the Building Inspection Office of the City of Erlangen, Property Drainage Division.

An inspection requirement also applies to shared sewer lines (e.g., in garage courtyards or row houses). Property owners must agree among themselves, under private law, on the cost shares to be borne by each individual. For economic reasons, it may make sense for several property owners to join forces and commission the inspection jointly. The contract for the inspection of jointly operated sewer lines should be awarded by a representative of the homeowners’ association.

Any use of the public sewer system during inspection or rehabilitation must be reported and coordinated with the City of Erlangen’s drainage department. Tel.: 09131/ 86 3215

Each property owner is responsible for ensuring that their property is and remains in good condition. A building’s site drainage system is an asset that must be maintained. No assistance or subsidies are provided by the municipality or the state.

If you have any questions about the leak test, a notice, or renovation, please feel free to contact the Building Inspection Office. Contact information:

• Email: grundstuecksentwaesserung@stadt.erlangen.de; Phone: 09131/ 86 1017 or
• Email: wasserschutzgebiet-gea@stadt.erlangen.de; Phone: 09131/ 86 1122.