So that the water stays clean!

Nowadays, many surfaces are paved for use (e.g. parking areas, storage areas, traffic routes, etc.) and often sealed tightly (e.g. asphalted, concreted). This is often done to prevent oils (mineral light liquids) from vehicles, machines, equipment or systems from entering the soil. To prevent these from entering the wastewater, so-called oil separators (technical term “light liquid separators”) must be integrated into the sewer system to remove the mineral oils contained in the wastewater.

Mineral oil separators are wastewater treatment systems that are used to remove mineral light liquids (e.g. petrol, diesel, etc.) from wastewater. They are mainly used in areas where these mineral oil products can get into the wastewater (e.g. petrol stations, parking lots, underground garages, etc.). They work on the principle of gravity or coalescence separation (droplets flowing together).

The operating principle is basically simple and is briefly explained here:
Wastewater containing light liquids enters the separator chamber via the inlet (4). Heavy substances (e.g. sand) sink to the bottom of the tank where they form the sludge trap (5). The light liquids (e.g. oil or gasoline), on the other hand, rise to the surface and are separated there in the light liquid layer (3). With this separation according to the gravity principle, a residual oil content of 5 milligrams per liter is achieved in separator class I by using a coalescence element (1) at the outlet of the separator. [1]

What legal regulations must be observed for the use of oil separators?

Mineral oil separator systems are subject to certain regulations and standards to ensure that they function properly. In Austria, there are various legal requirements for oil separators, particularly in industry and companies with waste water containing mineral oil. Here are the most important legal bases and standards:

Water Rights Act (WRG):
The WRG imposes an obligation to protect and keep waters clean. This is the potential basis for the obligation to install oil separators. These regulations stipulate that the quantity and harmfulness of wastewater must be kept as low as possible, taking into account the current state of the art(link to the law).

General Wastewater Emission Ordinance (AAEV):
It is issued on the basis of §33b of the WRG. It regulates the general limitation of wastewater emissions into watercourses and public sewers(link to the ordinance)

Indirect Discharger Ordinance (IEV):
It is issued on the basis of §32 of the WRG. The applicable Indirect Discharger Ordinance (IEV) regulates the discharge of oily wastewater into the sewage system. Companies that produce oily wastewater must conclude an indirect discharger contract (in accordance with the commercial law notice) with the sewerage company (e.g. clean water associations)(link to the ordinance).

ÖWAV Code of Practice 16:
Code of Practice 16 (Discharge of wastewater from the refueling, repair and cleaning of vehicles into public wastewater systems or bodies of water) from the Austrian Water and Waste Management Association (ÖWAV) provides helpful and specific information for the practical handling of oil separators. It describes the minimum requirements for wastewater pre-treatment with oil separation systems and is aimed at building owners, planners, operators and manufacturers(link to the regulation sheet)

STANDARDS[2]:

ÖNORM EN 858-1:
This standard specifies terms, nominal sizes, design principles, functional requirements, marking, testing and quality control for separator systems for light liquids. This standard applies to separator systems for light liquids which separate light liquids from wastewater by gravity and/or coalescence. This standard does not apply to the treatment of stable emulsions, solutions of light liquids in water, fats and oils of vegetable and animal origin.

ÖNORM EN 858-2:
This European standard applies to separator systems for the separation of light liquids of mineral origin from waste water. It does not apply to the treatment of fats and oils of vegetable and animal origin or emulsions and solutions. This European Standard provides guidance on the selection of nominal sizes and on the installation, operation and maintenance of light liquid separators manufactured in accordance with EN 858-1. It also provides a recommendation regarding the suitability of cleaning agents if these are discharged into the separator systems.

ÖNORM B 5101:
This ÖNORM applies to separator systems for light liquids (e.g. oil and petrol) and is only to be used in conjunction with ÖNORM EN 858-1 and -2. It contains additional requirements to ÖNORM EN 858-1 as well as requirements with regard to the leak test for systems in operation.

ÖNORM B 5104:
This ÖNORM contains requirements for the wastewater behavior of cleaning agents (“cold cleaners” or “solvent cleaners”) on a non-aqueous basis (hereinafter referred to as “cold cleaners” for short) that are used in trade and industry (e.g. in vehicle workshops, garages, petrol stations and relevant ancillary businesses) where wastewater treatment is carried out via mineral oil separators. This ÖNORM also includes the procedure for marking the conformity of cold cleaners with the standard.

Practical tips for the optimal operation of an oil separator

Dimensioning and installation:

• Oil separator systems must be dimensioned, installed, operated and maintained in accordance with the specifications in ÖWAV Code of Practice 16 and ÖNORM EN 858-1/2.
• A building permit is required for the installation and a discharge permit is required for the discharge of the treated wastewater.

Fire protection:

• Mineral oil separators are at risk of fire and explosion in all parts. Handling open flames or generating sparks in the area of the mineral oil separator is strictly prohibited!

Employee protection:

• If people enter the mineral oil separator, the air quality must first be checked using a gas warning device. Only if the air quality is suitable may a second person enter the sump while it is secured. The shaft must always be thoroughly ventilated before entering (open all covers and create air circulation if possible). The use of breathing apparatus is recommended.

Operation and maintenance:

• Observe the official and manufacturer-specific operating and maintenance instructions for your system. These may vary depending on the model and manufacturer.
• Oil separator systems must be regularly inspected, maintained, emptied and cleaned. This ensures proper and reliable operation.
• At least Monthly self-checks by the operator or an expert are necessary.
• A maintenance log must be kept (analog or digital)
• Every 6 months – maintenance by a specialist (the maintenance interval and the intensity of maintenance always depend on the dirt load to which the system is exposed)
• Every 12 – 24 months – carry out a wastewater analysis
• Every 5 years – general inspection (leak test of the tanks and camera inspection of the oil-carrying lines by a specialist company)
• Only ÖNORM-approved cleaning and care products may be used.
• Cold cleaners may only be removed at ambient temperature and without high pressure or hot water.

Permissible waste water:

• Oil separators may only receive wastewater that may contain light liquids.
• Rainwater may only be discharged from areas where light liquids may accumulate.

Prohibited substances:

must NOT be discharged via mineral oil separators:

• Mineral oils, waste oils, lubricants, battery acid, brake fluids, antifreeze, halogenated hydrocarbons and organic solvents.
• Waste water from small parts cleaning, underbody and cavity treatment, stable emulsions from washing lyes, concentrates and sludge from splitting plants

Responsible person:

• A reliable person must be named in the maintenance log to ensure and document the general supervision of the operation of the system.
• Every grease separation system should have a reliable person who is responsible for general supervision, maintenance and documentation.
• This person must receive training in the operation and maintenance of the grease separator.

Operating instructions:

• Operating instructions in German must be available for each separator system (in paper or digital form). This should be made available quickly so that the responsible supervisor can operate the system in accordance with the regulations.

Separator-friendly cleaning agents:

• In order to achieve good system efficiency in the long term, it is important that only cleaning agents that comply with the currently valid regulations (e.g. ÖNORM B 5104, B 5105 or B 5106) are used. Other cleaning agents can cause emulsions which cannot be sufficiently separated in the mineral oil separator.

Remember that the proper maintenance and operation of your grease separator system is not only required by law, but also helps to ensure economic efficiency, protect the environment and extend the service life of the system.

What difficulties can arise when operating an oil separator?

• Clogging: Oil separators can become clogged with oil, sludge and other residues over time. This impairs their efficiency and requires regular maintenance and cleaning.
• Incorrect dimensioning: If an oil separator is not correctly dimensioned, it cannot provide the required separation performance. This can lead to poor separation performance and thus to an increased load on the sewer system.
• Lack of training: Operators must be trained to operate and maintain the oil separator correctly. A lack of knowledge is often the cause of malfunctions or poor wastewater values.
• Environmental pollution: If oil separators do not function properly, oil residues can enter the environment and pollute downstream waters.
• Lack of maintenance: This leads to most malfunctions during operation. Regular inspections and maintenance work (by trained personnel) are therefore crucial for reliable and economical operation of the entire system.

As you can see, correct maintenance is once again the be-all and end-all for the reliability and efficiency of systems. Our MyBuilding24 app helps you to keep track of all maintenance work easily and reliably so that you don’t overlook this important maintenance and reminds you in good time when it needs to be carried out.

If you want to keep your properties, systems, machines and appliances in top condition and have your inspection and maintenance obligations under control, then use our
MyBuilding24 APP or follow this link and register today – https://mybuilding24.com/de/ – to keep your building running efficiently and reliably for a long time to come.

[1] https://www.aco.de/
[2] https://www.austrian-standards.at/d