Requirements and test methods for on site domestic wastewater treatment plants: the European standard (prEN 12566-3) compared to other international standards.

To ensure that domestic wastewater treatment plants run in an efficient and reliable way, certifications already exist while others will be implemented soon. To date, we have listed eight standards: four from European countries (Germany, Great Britain, The Netherlands and Norway), one project from the European Union, two from North America (USA and Quebec) and one from Australia and New Zealand together. The European procedure includes verification of structure stability, water tightness and treatment capacity at test centre (38 weeks). The American Standard sets minimal standards for materials, dimensioning, building and performances of the plants. It also highlights the information and minimum service that should be provided by the manufacturer and distributors. The review process relating to treatment performances shares major similarities with the EU project since both documents were elaborated almost simultaneously. Australia and New Zealand have adopted a series entitled On-site Domestic Wastewater Treatment Units made up of three parts. The third one integrates construction requirements and describes quite an interesting procedure to efficiently test the small plant: after approximately 13 weeks of testing (half the total duration), the aeration chamber (provided it exists) is filled with sludge from septic tanks to simulate its operation after several years. Overview of the treatment efficiency test procedures of the three main standards is given.