Indirect discharges

What are indirect discharges?

An indirect discharge is industrial wastewater that flows through the sewer system to a wastewater treatment plant, rather than directly into surface water.

This water may contain harmful substances, such as heavy metals and PFAS. These substances can cause problems for both the treatment process and the environment.

Municipalities and environmental agencies mon supervision s of these discharges.

Why is this important?

The challenge is growing. Under the European Water Framework Directive, we must ensure cleaner water by 2027.

The focus here is on reducing substances of very high concern, also known as SVHCs.

Examples include PFAS, pharmaceutical residues, and other chemicals that pose risks to water quality and health.

What do we do?

We are working with environmental agencies to develop a better approach. Our goal is to establish a clear and effective framework for permitting, supervision , and enforcement (VTH).

We do this by:

  • to gain a better understanding of what is being discharged;
  • collect and share data with one another;
  • Strengthening Cooperation in the Water Cycle;
  • and work toward a single, uniform approach in the region.

Frequently asked questions

Why did you conduct the pilot?

The pilot project was designed to help improve 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 participated 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 was the pilot conducted?

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?

Following the pilot, the implementing parties further defined the VTH tasks related to indirect discharges of industrial wastewater into the sewer system. This included site visits and the production of two short films explaining what an indirect discharge is and why it does not belong in the sewer system.