Wastewater Sampling and Analysis

The danger of wastewater to public health comes from direct contact or contact via aerosols, mainly through water-based activities. In most cases, contamination is linked to domestic wastewater, with water acting as a vector between humans.

The Water Framework Directive (WFD) has been transposed into French law as the Law on Water and Aquatic Environments (LEMA, 30/12/2006). It addresses many issues relating to water use and the protection of aquatic environments, but in particular, through the decree of July 21, 2015, and its revisions (August 24, 2017, and July 31, 2020), self-monitoring of the operation of wastewater treatment plants (including analysis of inlet and outlet water) and collection systems.

The SDAGE (Water Development and Management Master Plan) is also one of the main players involved in water management.

The aim of this monitoring is to assess and maintain the effectiveness of sanitation systems, but also to meet the objectives of achieving good water status, as defined by the European Water Framework Directive (WFD). It must also enable project owners to report on the operation of their sanitation systems to water stakeholders (Water Police, Water Agency, and SATESE in particular). The Water Police services use the data provided to determine the annual compliance of the sanitation system with local, national, and European regulations.

Project owners of wastewater treatment plants and wastewater collection networks are required to set up self-monitoring of the structures for which they are responsible. These provisions are defined by the decree of July 21, 2015, which came into force on January 1, 2016, and by the amendments made to it (ministerial decrees of August 24, 2017, and July 31, 2020).

The regulatory self-monitoring points (A) for each sanitation system are specified in their SANDRE scenarios (treatment plants and collection networks) and are described in the table below. Non-regulatory points are logical points (S for the wastewater treatment plant and R for the sewerage network). SANDRE scenarios are specific documents that formalise data exchanges (nature of parameters, frequency of transmissions) between project owners and water stakeholders, within the framework of a single codification and a common language.

The level of self-monitoring at wastewater treatment plants varies according to their treatment capacity. It ranges from no self-monitoring (systems with a capacity of less than or equal to 12 kg/day BOD5 or 200 PE) to 365 measurements per year (systems with a capacity greater than or equal to 18,000 kg/day BOD5 or 300,000 PE).

For bypass points (points A2, A5), it ranges from a simple visual check to a precise quantification of the bypassed pollution flows.

An annual inspection is carried out by the Water Police (DDT, DRIEAT) on the basis of the data provided and unannounced checks. The project owner is informed each year, before June 1, of the compliance or non-compliance status of the sanitation systems that concern them.

The Water Agency is also involved in the assessment of sanitation systems for collection and treatment facilities exceeding 120 kg/day BOD5 (see Article 21).