Pilot indirect discharges

The pilot is a trial project focusing on supervision indirect discharges of industrial wastewater in various industrial sectors in the area. Samples of the wastewater were taken and analyzed for various substances in order to gain a better understanding of the substances discharged by the different sectors.

The pilot focuses on the most harmful substances that can occur when industrial wastewater is discharged into the sewer system and that can be dangerous for surface water: the so-called substances of very high concern (SVHC) and the priority substances of the European Water Framework Directive (WFD). Substances that cause problems for the functioning of the sewer system and wastewater treatment plants (WWTPs) were also considered.

It is also a pilot project to gain more knowledge and experience in conducting company visits to take samples of indirect discharges and everything that this entails. A number of colleagues at the three environmental services and HHNK have followed a training course within the pilot project specifically aimed at further developing knowledge about indirect discharges of industrial waste water into the sewer system. In addition, we are sharing the knowledge and experience we have gained from the pilot project with colleagues from water authorities and environmental services throughout the country.

Frequently asked questions

What do we mean by indirect discharge?

Wastewater from businesses that is discharged into the sewer system and not directly into surface water or a wastewater treatment plant is referred to as indirect discharge. These indirect discharges from businesses into the sewer system can affect the functioning of the sewer system, the treatment process, and the quality of the treated wastewater that enters surface water via the wastewater treatment plant.

Why are you conducting the pilot?

The pilot aims to contribute to improving the quality of surface water and the health of the area's residents.

When did the pilot start?

The pilot started in April 2023 and ran until the end of 2023. In the first quarter of 2024, all results were processed and work was done on finalizing the final report.

Who is participating in the pilot?

IJmond Environmental Service, North Holland North Environmental Service, North Sea Canal Area Environmental Service, and Hollands Noorderkwartier Water Board. In coordination with: Province of North Holland, PWN Drinking Water Company, Rijkswaterstaat North Holland Directorate, and on behalf of the 26 municipalities.

Where will the pilot be held?

In North Holland, in the area above the North Sea Canal (also known as Noorderkwartier) and 26 municipalities.

Who paid for the pilot and how much did it cost?

The three environmental services and the water board invested the necessary time in the pilot. In addition, the Intergovernmental programme VTH Tasks (IBP-VTH) provided a subsidy for the costs of program management, hiring subject matter experts, analyzing the wastewater samples taken, and training the supervisors. The subsidy amounted to €250,000.

What is the next step/approach after the pilot?

The implementing parties are currently exploring the next steps to further develop the VTH tasks on indirect discharges of industrial wastewater into the sewer system after the pilot.