Water emissions monitoring program: building it and implementing it effectively

The RSDE provides a framework for monitoring hazardous substances and micropollutants in water. What are your obligations to ensure compliance and anticipate inspections?

Monique Argaud
EHS Consultant
Update : 
12.09.2025
Publication: 
08.09.2022
Contents
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Zoom in on a subject that's even more topical with today's drought episodes.

A water emissions monitoring program tracks macropollutants(a group of substances including suspended solids, organic matter and nutrients such as nitrogen and phosphorus) and hazardous substances or micropollutants(substances or groups of substances that are toxic, persistent and bioaccumulative, and other substances or groups of substances that are considered, to an equivalent degree, to be of concern).

The construction and implementation of a monitoring program for emissions into water involves taking into account various regulatory obligations, the nature of which depends on the site's administrative situation, the origin of emissions (wastewater or stormwater), the characteristics of its emissions into water, the treatment and discharge methods in place, its geographical location and local environmental conditions.

Obligations under ICPE regulations

These regulations are based on ministerial decrees governing the site's facilities (IED subject to authorization, registration or declaration) and, where applicable, its prefectoral decree (AP).

These obligations were profoundly modified by the RSDE order of August 24, 2017, with the new monitoring procedures for hazardous substances coming into force on January1, 2018.

The rules to be observed to comply with its obligations and detailed in two Ministry of the Environment guides published in 2018 include:

  • The monitoring of hazardous substances generally includes sector-specific substances, other global parameters and other hazardous substances used to qualify the status of water bodies, including other specific pollutants of ecological status that have a local impact (for the latter, see table 44 in appendix 3 of the decree of January 25, 2010 for the applicable EQS). For authorized activities covered by article 33 of the decree of February 2, 1998 (chemicals, metal production or processing, etc.), the ELVs for substances characteristic of industrial activities set out in article 32-3 are replaced by those given in the specific section dedicated to the activity sector. Discharges of substances not listed in article 33 must be regulated as in the general case, according to the ELVs set out in article 32-3.
  • If an ELV is also prescribed by a PA, discharge levels must not exceed the more stringent of the two.
  • When a site carries out several activities covered by several ministerial decrees with different ELVs, the most restrictive ELV must be applied at the site outlet.
  • A ministerial decree may require the inspection to be carried out at the plant exit rather than at the site exit, e.g. the decree of December 14, 2013 applicable to facilities subject to registration under heading 2921, the decree of August 3, 2018 applicable to facilities registered under heading 2910...
  • When the operator subcontracts its monitoring program, it must ensure that it achieves limits of quantification (LOQ, a value below which it is difficult to quantify a substance with acceptable uncertainty) for "parameter-matrix" pairs that are less than or equal to 30% of the applicable ELVs. If compliance with the 30% emission limit value results in an achievable LQ lower than the regulatory LQ (notice of September 19, 2019), the regulatory LQ remains the reference. This criterion is used to declare the discharge compliant/non-compliant, taking into account the measurement uncertainty.
  • Use an accredited sampling laboratory for subcontracting the monitoring program and carrying out controls (initial calibration, external recalibration, unannounced), and an approved analysis laboratory for controls and an accredited laboratory for subcontracting the monitoring program. As of July1, 2023, a regulatory relief will come into force, as the annual adjustment inspection, which only covers analysis, will become a biennial adjustment inspection, subject to the existence of at least one annual measurement in the monitoring program. In addition, this recalibration test is no longer mandatory if the operator's emissions are already monitored by an approved laboratory (sampling and analysis).
  • In the case of a one-off or discontinuous discharge, spot sampling directly in the tank or basin is not appropriate. Sampling should be carried out either automatically, proportional to the time the discharge pump is running or the discharge valve is open, or punctually if the outlet does not allow for the installation of an automatic sampler, or if the discharge time is short (30 minutes to 3 hours). In all cases, if the draining time exceeds 1 hour, the number of samples taken must be at least five per hour.
  • A sampler used to monitor macropollutants is not suitable for monitoring hazardous substances, which require a Teflon suction hose and a glass collection bottle.
  • For pollutants not covered by any of the reference methods in the February 22, 2022 notice, the sampling procedure used enables statistical representation of parameter trends.
  • Particular care must be taken when assessing discharge conformity. Thus, unless otherwise stipulated, in the case of permanent self-monitoring (at least one representative measurement per day) and 24-hour sampling, the site is compliant if 90% of monthly values are below the ELV, and none of the values exceeds twice the ELV. If, on the other hand, instantaneous sampling is carried out, no measurement result exceeds twice the ELV. In the case of non-permanent self-monitoring, 24-hour sampling is declared compliant when 100% of results are below the ELV.
  • If the discharge is made into the same medium as the sampling medium, compliance with emission limit values can be assessed by considering the net concentration resulting from the industrial facility's activity. The sampling medium and the discharge medium are considered to be different, particularly when a site draws from groundwater and discharges into surface water, or when a site draws from the municipal network and discharges into the river.

Obligations arising from regulations governing the determination of the amount of non-domestic water pollution charges levied by water agencies

In this respect, a site is subject to regular discharge monitoring (SRR) as soon as, for at least one of the components of pollution, the theoretical level of pollution reaches or exceeds the value mentioned in Article R.213-48-6 of the French Environment Code: 600 t/year in TSS or COD, 300 t/year in BOD5, 40 t/year in NGL, 10 t/year in Pt, 10,000 kEquitox/year in Inhibitory Matter, 10,000 kg/year in Metox, 2,000 kg/year in Halogenated Compounds adsorbable on activated carbon, 100,000 m3*S/cm/year in dissolved salts or 360 kg/year in HDS (Hazardous Substances in Water).

In the context of a RRS, the monitoring program provides for the constitution of a 24-hour sample for the daily analysis of a pollution constituent, representative of the facility's activity. For other pollution constituents not subject to daily analysis and whose theoretical pollution level exceeds the SRR thresholds, the monitoring program is set by ministerial decree.

Pour les éléments constitutifs de la pollution dont le niveau théorique de pollution est < au seuil d’assujettissement au SRR, l’établissement réalise une analyse d’un échantillon moyen journalier chaque mois, à l’exception de l’analyse de la toxicité aiguë réalisée chaque trimestre et de l’analyse des SDE une fois/an.

EDSs composed of sixteen substances (cf. article R. 213-48-3 of the French Environment Code) may benefit from special arrangements if it is demonstrated, on the basis of measurement results representative of the facility's polluting activity, that the analytical concentrations of one or more substances making up the parameter are below the LQ. In agreement with the Agence de l'Eau, this substance or these substances are excluded from the SRR for a period of five years. At the end of this period, a determination is made of all the substances making up the SDE pollution component, in order to adjust the monitoring program if necessary.

The SRR must be approved by the water agency. A diagnosis of the SRR's operation is carried out at least once every two years, by an authorized body.

For a site not subject to SRR, the water pollution charge is based on a measurement campaign carried out on discharges by a body approved by the Water Board, before the implementation of a pollution control system.

Obligations arising from connection authorization regulations

All discharges of non-domestic wastewater into the public sewerage system must first be authorized by the mayor or the organization in charge of sanitation (e.g., the local community or a private company in the case of delegated management). This authorization sets out the characteristics that the wastewater must meet in order to be discharged, as well as the monitoring program. The results of the monitoring program are transmitted to the owner of the wastewater system, independently of the obligation to transmit them to the inspectorate. Thanks to the GIDAF application, the local authority can retrieve the monthly ICPE declaration via reader access codes supplied by the operator.

Mastery of the water emissions monitoring program, integrating all the regulatory obligations presented in this article, should enable any plant operator to calmly consider future challenges in the field of water, such as :

  • The need to reuse treated wastewater
  • For priority hazardous substances covered by Directive 2013/39/EU (Dioxins and dioxin compounds including certain PCDDs, PCDFs and PCB-TDs, PFOS, HBCDD, Heptachlor and heptachlor epoxides, Dicofol, Quinoxifene, Trifluralin, DEHP), compliance with ELVs by January 1, 2023 and their elimination* by 2033.
  • For priority substances covered by Directive 2013/39/EU (Dichlorvos, Terbutryne, Aclonifene, Bifenox, Cybutryne and Cypermethrin), compliance with ELVs by January 1, 2023 and their gradual reduction by 2033.
  • Elimination of the priority hazardous substances anthracene and endosulfan by 2028

*Fora site, the elimination of substances must be understood as a maximum reduction at an acceptable cost when the reduction solution is technically possible to implement according to local characteristics (location, geography, space, etc.).

NOTE: for other priority substances (trichloromethane, nickel and compounds, lead and compounds, dichloromethane, octylphenols...) / priority hazardous substances (nonylphenols mercury and compounds, cadmium and compounds...), their reduction/elimination must be effective by 2021, in accordance with the decree of July 8, 2010.

Photo credit: 277318406 @settapong