Substances hazardous to water

Heating oil storage facilities are inspected

Operators in Velstove and Ehmen are now receiving mail from the city

Operators of heating oil storage facilities with a capacity of more than 1,000 liters will also be contacted in 2023. The relevant citizens in the districts of Velstove, which is partly located in the drinking water protection area, and Ehmen will soon receive mail from the city of Wolfsburg. The lower water authority wants to inform them that these systems must be inspected by an expert.

Heating oil tanks that were installed before December 17, 1997 were not subject to mandatory inspection when they were first commissioned. Since 1997, all above-ground and underground heating oil tank systems with a filling volume of more than 1,000 liters have been subject to mandatory inspection prior to commissioning. A court ruling stipulated that the inspection obligation also applies to existing systems and must be carried out at a later date, as old systems in particular can pose a risk to surface water and groundwater.

The subsequent commissioning inspection involves an expert checking the current condition of the storage facilities. This identifies defects such as signs of wear or a lack of safety standards, so that risks to water bodies, groundwater and soil, as well as other environmental goods and assets, can be prevented.

Significant changes to the system must also be reported to the authorities. A significant change is, for example, the replacement of the storage tank(s). If you have decommissioned your facility, the decommissioning certificate must be sent to the Lower Water Authority. "With this inspection, the city of Wolfsburg is fulfilling a legal obligation. At this point, I would ask those affected for their understanding and cooperation," explains City Councillor Andreas Bauer, Head of Citizen Services, Finance, Fire and Disaster Protection.

Anyone who owns a heating oil storage facility with a capacity of more than 1000 liters and has not yet received a letter from the city should take action themselves. The notification of an existing heating oil storage facility, a significant change or the decommissioning certificate can be conveniently completed from home using the heating oil storage facility notification form in the online town hall on the page linked below and sent to the Lower Water Authority. Alternatively, you can still send it by post. The notification form can be downloaded from the online town hall and completed by hand.

As of June 2018, the Lower Water Authority of the City of Wolfsburg will request numerous operators of above-ground heating oil systems to have their heating oil tank inspected by an approved expert and, if necessary, to have any defects found remedied or the tank system retrofitted if this is required.

This applies to above-ground heating oil tank systems with a filling volume of 1,000 liters to 10,000 liters that have never been inspected by an expert body or that were installed before December 17, 1997.

Testing is carried out in accordance with the currently applicable legal standards. This may mean that old tanks have to be retrofitted. If the expert finds significant or dangerous defects in the tank system, the owner must rectify these and have the system inspected again.

In Wolfsburg, there are currently around 4,200 heating oil tanks in operation. If these systems have defects, they can pose considerable risks to surface waters and groundwater.
Heating oil is considered a substance hazardous to water and must be stored in a particularly safe manner. Anyone operating a heating oil tank is obliged to ensure that the heating oil tank system is installed and operated in accordance with regulations. In the interests of preventive water protection, heating oil tank systems must be monitored regularly. If leaking heating oil contaminates the soil or groundwater, the system operator will incur significant cleanup costs.

Heating oil tanks installed before December 17, 1997, were not subject to mandatory inspection when they were first put into operation. This only applied to all underground tanks and storage tanks with a filling volume of more than 10,000 liters. Since 1997, the initial inspection requirement prior to commissioning has also applied to all aboveground heating oil tank systems with a filling volume of 1,000 liters to 10,000 liters. In Wolfsburg, a subsequent commissioning inspection of already existing systems has not yet been initiated. In a ruling by the Braunschweig Administrative Court, it was determined that the inspection requirement also applies to existing systems and must be made up for, as old systems in particular can pose a risk to bodies of water.

The operator of a heating oil system is responsible for tank safety. According to the applicable legal regulations, the following obligations in particular must be observed.

• Obligation to notify
• Plant documentation/leaflet
• In-house and external monitoring
• Plant inspection by experts
• Specialist company obligation
• Filling of heating oil tanks
• Notification of damage/measures in case of fuel oil leakage
• Decommissioning of heating oil tanks
• Obligation to retrofit
• Plastic tanks for the storage of heating oil
• Heating oil tanks in flooded areas

Neglected maintenance can lead to serious environmental damage and high remediation costs. The operator of a plant in which substances hazardous to water are handled must therefore regularly check the tightness of the plant and the functionality of the safety equipment as part of self-monitoring, i.e. so frequently that damage can be detected in good time and countermeasures can be taken. The inspection is primarily carried out in the form of a visual and functional check(legal basis: paragraph 46 AwSV).

In this process, the tank and the pipelines are checked for leaks and the fill level and the consumption quantities are checked by visual inspection. In the case of double-walled tanks with a leak detector, it must be ensured that the leak detector is always in operation and that an alarm is also reliably noticed.

In the case of a tank in the collection room, this must be checked regularly for leaks and leaks of heating oil (leakage). In the case of systems subject to mandatory testing, self-monitoring must be supplemented by external monitoring by an expert.

The legal obligation to operate as a specialist applies to all underground storage facilities and to aboveground storage facilities with a storage volume of more than 1 m³.
In the case of facilities requiring specialist operation, the operator must commission a certified specialist company with the construction, internal cleaning, repair and decommissioning of the facilities and facility components. (Legal basis: paragraph 45 and paragraph 62 AwSV)

Anyone who intentionally or negligently constructs, cleans the inside of, repairs or decommissions a system without being a specialist company commits an administrative offense (legal basis: Section 65 No. 25 AwSV).

Storage facilities may only be filled if the required safety equipment is in proper working order and the facility has no obvious defects or damage. Before filling the tanks, the tank truck driver must determine the available free space in the tanks. For this purpose, the level indicator must be read or, in the case of translucent tanks, the level must be visible. The entire filling process must be monitored. If this cannot be ensured, the system must not be filled.

Safe refueling: limit value transmitter

A limit switch on the heating oil tank protects against overfilling damage. It automatically shuts off the oil supply as soon as the tank level reaches a certain mark. Overfill protection is mandatory for all underground tanks as well as for aboveground tank systems with a capacity of more than 1 cubic meter.

If there is a risk that heating oil may leak or if this has already happened, the operator must immediately take measures to limit the damage (legal basis: section 24 para. 1 AwSV). The affected plant must be taken out of operation or emptied into other, safe containers if a hazard to soil and water may arise.

In principle, the leakage of a not insignificant quantity of heating oil must be reported immediately to the local fire department, police station and the lower water authority of the city of Wolfsburg if the substances have entered or may enter the subsoil (groundwater), the sewage system or a surface water body.

Decommissioning is the permanent shutdown of an oil storage facility or parts of a facility. Decommissioned oil storage facilities or parts of facilities must be secured in such a way that there is no danger to third parties or the environment.

Fuel oil storage facilities may only be decommissioned by specialist companies approved for this purpose. These companies have the necessary expertise and ensure proper disposal of oil residues and sludge. In principle, the operator must arrange for a decommissioning inspection to be carried out by an expert after completion of the work. This expert must check whether the tank facility has been emptied and cleaned, whether filling nozzles have been removed or secured against accidental use, and whether there are any indications of soil or groundwater contamination.

In any case, the decommissioning of a heating oil storage facility must be reported in writing to the lower water authority.

In principle, the following applies: For systems that have been properly installed and operated in accordance with the previous legal regulations, there is no automatic retrofitting obligation.

An expert first checks whether and to what extent there are deviations from the current requirements for heating oil systems and provides information in good time about any necessary adaptation measures.
Based on the inspection report, the water authority of the city of Wolfsburg can order retrofitting measures if necessary, provided this is required for reasons of preventive water protection(legal basis: Section 68 AwSV).

In general, however, as an operator of an oil heating system, you are well advised to have your system adapted to today's technical standards by a specialist company, even without an express order from the authorities, and thus significantly increase the safety of the system.

Modern limit value transmitters

Especially older storage systems (older than approx. 10 to 15 years) are still often equipped with limit value transmitters of the old type. In these models, the PTC thermistor is still equipped with a closed plastic protective sleeve with holes. These holes can become clogged, preventing heating oil from reaching the PTC resistor during filling. The pump on the tanker no longer switches off when the maximum filling level is reached. The result: the heating oil overflows.
Therefore, equip your storage system with a new type of limit switch. These no longer clog because the sleeve is slotted and open at the bottom.

Conversion to single-line system (suction line)

Do you still have a storage system with the outdated principle of a supply and return line to the burner system?

This type of heating oil extraction involves a large number of risks, since the leakage of heating oil from a leaking return line is often not noticed quickly enough. Although heating oil escapes unimpeded to the outside via a leak in the line, the burner system will continue to run trouble-free as long as heating oil can be removed from the tanks.
Conclusion: Have the return line from the oil burner to the tank shut down by a certified specialist company and have the oil supply converted to a "single line system".

Retrofitting with an empty lift safety device

If the lowest point of the suction line is lower than the maximum permissible liquid level in the tank, there is a risk that heating oil may leak out automatically due to suction lift effect in the event of a break in the suction line to the oil burner.

The solution: retrofitting with an approved siphon protection valve reliably prevents heating oil from leaking.

Older plastic tanks made of polyethylene (PE) or polyamide (PA) may experience critical material fatigue over the years.

Generally, plastic heating oil storage tanks are designed for safe operation for about 30 years. Due to the aging processes of the plastic, the stability is then no longer proven. Regardless of a visually proper condition of the tanks, manufacturers therefore recommend a regular inspection after 25 years, but at the latest after 35 years the tanks should be taken out of service or replaced. If the tank system continues to be operated, this is done at the user's own risk.
You should have plastic tanks with deformations, bulges, embrittlement, cracks or severe discoloration replaced immediately, regardless of the age of the system.

City of Wolfsburg
Environmental Agency - Lower Water Authority -
Porschestraße 49
38409 Wolfsburg

Contact person:

Ms. Krause
Telephone: 05361 28-1961

Ms. Grune
Phone: 05361 28-2425

Ms. Diesner
Telephone: 05361 28-1519

Fax: 05361 28-1877
E-Mail: wasserbehoerde@stadt.wolfsburg.de

Opening hours

Monday and Tuesday: 08:30 to 16:30
Thursday: 08:30 to 17:30
Wednesday and Friday: 08:30 to 12:00