You want to open up new markets with small wastewater treatment plants, or launch a new model on the market? If so, you have found the right partner in PIA.

You can count on us to answer all the necessary questions about market requirements and the certification of your products. Indeed, you can launch conventional or innovative projects most successfully with a competent partner. We will support you with our unique know-how whenever your product has to comply with the water legislation requirements in different countries or regions. Since we actively participate in numerous national and international boards as well as on technical and standardisation committees, we are always up to date: something your company can benefit from. Take advantage of our competence, motivation and determination to achieve your goals.

"Sustainable Certification" is more than just a slogan. It describes the two decisive core elements for you: first, certifications and test reports should be used as long as possible and, second, they represent not only the legal basis for your sales, but are also welcome evidence of how well your product performs.

The tests, followed by declaration of performance, are the key to success. We would be pleased to consult you on these matters. Let us work together efficiently as partners. Take the time and give us a call.

CE tests according to EN 12566

The basis for a successful market entry in Europe is the CE marking of your product. For this purpose, the series of standards – EN 12566 – is used. Five of the seven standards have been harmonised and, with our support, you can receive a declaration of performance according to one of these standards and place it on your product. With it, small wastewater treatment plants can be traded legally throughout Europe.

EN 12566 complete


The standard EN 12566 is divided into several parts, each of which defines the basis for the respective tests:

NSF International tests

Dr. rer. nat. Martina Defrain

Head of International Testing / Water (Re)use
  +49 241 75082-29

Tests according to NSF/ANSI standards are recommended if you would like to enter the American and Asian markets with relative ease.

Currently, the only place in Europe where tests according to NSF/ANSI Standards 40, 245 and 350 can be carried out is on PIA's test field in Aachen. For over ten years, PIA has maintained successful cooperation with NSF.

ParameterNSF 40NSF 245NSF 350
E. coli    

Australian tests

Dr. rer. nat. Martina Defrain

Head of International Testing / Water (Re)use
  +49 241 75082-29

AS 1546.3:2017
On-site domestic wastewater treatment
Units Part 3: Secondary treatment systems

The new AS 1546.3:2017 sets out requirements for the design, commissioning, performance and conformity testing of secondary treatment systems (STS) and advanced secondary treatment systems designed to treat domestic wastewater. The design hydraulic treatment capacities that may be tested in accordance with this Standard range from a minimum of 1200 L/d to a maximum of 5000 L/d. Guidance on installation, operation and maintenance is also provided.

Material tests

Daniela Schmitz, M.Sc. RWTH

Testing Engineer
  +49 241 75082-29

The materials listed in the standard for tanks of small wastewater treatment plants are varied as the possible treatment processes themselves. The materials allowed range from classic reinforced concrete, via fibre-reinforced plastics through to stainless steel.

All materials, or containers and tanks manufactured from them, have to prove their suitability in terms of their intended use. In addition to tests for structural behaviour and water tightness, there are also the proof of reaction to fire, durability and a leaching test to verify if any dangerous substances are present.

PIA GmbH has partners and co-operative bodies throughout Europe and can provide the appropriate material tests and the required expertise, wherever needed.

Special tests

Thanks to close cooperation and individualised support, we are also able to offer you special tests. This way, we can confirm even more performance options of your system, even if they are not necessary for the CE marking.

The following special tests are possible:


Such a special test, however, does not replace the test procedures according to EN 12566 and cannot alone count as a valid test. Only when a small wastewater treatment plant has successfully completed all relevant tests according to EN 12566 can the system be CE-marked.

Recent News



Guidelines for technical performance test of small sewage treatment systems in China

PIA GmbH and CWEG (China Water Environment Group) are preparing a project for the Chinese Environmental Protection Industry Association to develop "Guidelines for technical performance test of small sewage treatment systems".

Visit for more information.

List of manufacturers and their products which performed successfully in EN 12566-7 tests (tertiary treatment units)

A list of manufacturers and their respective products which have successfully undergone testing in accordance with EN 12566-7 is now available in our EN 12566 tests / Part 7 section!

New legal developments in France for small wastewater treatment plants

For manufacturers of small wastewater treatment plants, the requirements for the approval of their products in France could soon change. At present, the following decree has been submitted to the relevant authorities in Brussels for approval:

“ORDER of […] amending the Order of 7 September 2009 laying down the technical specifications applicable to individual sewerage systems receiving a gross load of organic waste less than or equal to 1.2 kg/day of BOD5 and the Order of 27 April 2012 on the implementing procedures for the inspection of individual sewerage installations”

This decree essentially relates to systems and plants that cannot be CE marked. According to Article 8, the following conditions apply to systems:

To perform the treatment, the system shall include

  • a primary treatment device, built in situ or prefabricated;
  • a secondary treatment device using the purifying power of the soil.

This applies only to systems complying with EN 12566-2 (soil infiltration systems) or EN 12566-5 (filtration systems for pre-treated domestic wastewater). The decree regulates, among other things, requirements for the test programme (44 weeks in total), wastewater pre-treatment and inlet and outlet concentrations.

The simplified assessment procedure described in Appendix 3 of the decree applies to all treatment systems according to hEN 12566 Part 3 or Part 6. The basis for the assessment is the 38-week test programme corresponding to the initial type testing of the standard. The simplified assessment regulates among other things

  1. A standard test performed without desludging shall be demonstrated.
  2. There is a new evaluation procedure for the effluent concentrations for the parameters BOD5 and SS for which the value Lsup must be calculated (Lsup = m 1.34 x s; m = mean value; s = standard deviation - for details see appendix 3 of the decree)
  3. The evaluation of inlet quality which previously only included BOD5 must now also include the additional parameters COD and SS.