Pilot indirect discharges

The pilot is a pilot project with the focus: monitoring indirect discharges of industrial wastewater in different business branches in the area. Samples of wastewater were taken and analyzed for various substances to gain a better understanding of the substances discharged by the various industries.

The pilot focuses on the most harmful substances that can occur when company wastewater is discharged into the sewer system that can be hazardous to surface water: the so-called substances of very high concern (PHS) and the priority substances of the European Water Framework Directive (WFD). This included substances that pose problems for the operation of sewers and wastewater treatment plants (WWTPs).

It is also a pilot to gain more knowledge and experience with conducting company visits where samples of indirect discharge are taken, and what is involved. A number of colleagues at the three environmental services and HHNK have followed training within the pilot specifically aimed at further developing knowledge about indirect discharges of company wastewater to the sewer system. In addition, we share our knowledge gained and experiences from the pilot nationwide with colleagues from water boards and environmental services.

Frequently Asked Questions

What do we mean by an indirect discharge?

Wastewater from companies that is discharged to the sewer system and not directly to surface water or WWTP is called an indirect discharge. These indirect discharges from businesses to the sewer system can affect the operation of the sewer system, the treatment process and the quality of the treated wastewater that goes to surface water via the sewage treatment plant.

Why are you doing the pilot?

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

When did the pilot start?

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

Who is participating in the pilot?

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

Where will the pilot be held?

In North Holland, in the area above the North Sea Canal (which is also called Noorderkwartier) and 26 municipalities.

Who paid for the pilot and what did the pilot cost?

The three environmental services and the Water Board invested the necessary time in the pilot. In addition, the Interadministrative Program for Strengthening VTH Tasks (IBP-VTH) provided a grant for the costs of program management, hiring substantive expertise and the costs of analyzing the wastewater samples taken and also training the supervisors. The grant amount was €250,000.

What is the next step/approach after the pilot?

The implementing parties are currently exploring follow-up steps to further flesh out VTH tasks on indirect discharges of industrial wastewater to the sewer system after the pilot.