Small wastewater treatment plants

Small wastewater treatment systems serve to purify domestic foul water from buildings with up to 50 inhabitants. The wastewater is treated using physical and biological processes.

Regulatory framework

Small wastewater treatment plants covered by harmonised standards EN 12566-3 and EN 12566-6 must bear the CE marking.

Plants and systems not covered by the harmonised European standard (e.g. retrofit kits) fall under the Ordinance on the determination of the suitability of construction products and construction techniques under water law by means of verifications in accordance with the Building Codes of the federal states (WasBauPVO). Cf. WasBauPVO, Section 1(1)(a) 'Small wastewater treatment plants designed for wastewater volumes of up to 8 m3/day'.

DIBt grants national technical approvals (abZ) in combination with a general construction technique permit (aBG) for the latter. The abZ/aBG serve to verify the suitability of the plants both from a construction and water legislation point of view. (Please also see Retrofit kits for installation in existing wastewater treatment plants for creation of small wastewater treatment plants).

European Technical Assessments (ETAs) can also be issued for small wastewater treatment plants which are not (fully) covered by EN 12566-3 or EN 12566-6. The plants can then be placed on the market bearing the CE marking. Provisions pertaining to the application fall within the responsibility of the local authorities.

As a result of the implementation of the judgement of the European Court of Justice of 16 October 2014 in case C-100/13, national technical approvals are no longer granted for products if they bear the CE marking on the basis of the Construction Products Regulation (Regulation (EU) No 305/2011). The products may not be marked with the national conformity mark. Approvals for which the period of validity has not yet expired are listed below. They can be used on a voluntary basis to prove fulfilment of the regulatory requirements.

Application forms

National procedure

A national technical approval (abZ) and/or oder general construction technique permit (aBG) is granted upon application (see Model Building Code (MBO), Sections 16a(2) and18(2) and (4)). This also applies to amendments and supplements to, or renewals of existing approvals and/or construction technique permits.

No formal requirements apply. The following information is needed: name and address of the applicant, description of the product and/or construction technique and its field of use or application, type of decision required (new decision, amendment or supplement to, or renewal of, an existing decision).

Please feel free to use the template below.

Application for a national technical approval and/or construction technique permit (3 pages)

Version: January 2018; Application form

Application for amendment / supplementation / renewal of a national technical approval and/or construction technique permit (4 pages)

Version: January 2018; Application form

Guideline: How to provide drawings for national technical approvals and general construction technique permits (5 pages)

Version: July 2017

  • abZ/aBG
  • Z = new decision | E = supplement | Ä = amendment | V = renewal | G = valid until
    Subject concerned Applicant Decision no. Validity
    from / to
    Kleinkläranlagen mit Abwasserbelüftung zur Freiaufstellung Belebungsanlagen mit Membranfiltration, Typ BUSSE MF - HKA und Typ BUSSE MF - G-HKA für 4 bis 50 EW Ablaufklasse D+H

    Busse Innovative Systeme GmbH

    Zaucheweg 6

    04316 Leipzig

    Z-55.3-317 Z: 20.01.2021
    G: 14.04.2025
    Kleinkläranlagen mit Abwasserbelüftung zur Freiaufstellung Belebungsanlagen mit Membranfiltration Typ BUSSE MF - HKA und Typ BUSSE MF - G-HKA für 4 bis 50 EW Ablaufklasse D+H+P

    Busse Innovative Systeme GmbH

    Zaucheweg 6

    04316 Leipzig

    Z-55.3-327 Z: 20.01.2021
    G: 30.06.2025
    Kleinkläranlagen mit Abwasserbelüftung zur Freiaufstellung Belebungsanlagen mit Membranfiltration, Typ BUSSE MF - HKA und Typ BUSSE MF - G-HKA für 4 bis 50 EW Ablaufklasse N+H

    Busse Innovative Systeme GmbH

    Zaucheweg 6

    04316 Leipzig

    Z-55.3-60 Z: 20.01.2021
    G: 02.07.2025
    Bepflanzter Bodenfilter Typ Burg I für 4 bis 50 EW Ablaufklasse C

    Umweltgestaltung Frank Hildebrand

    Weidenweg 10A

    03096 Burg im Spreewald

    Z-55.4-91 Z: 09.12.2020
    G: 09.12.2025

Stefan Hartstock
Head of Section (acting) – Wastewater Treatment Plants

Phone +49 30 78730-280
Email shr(at)dibt(.)de

Legal reference documents

Testing, certification, inspection