The Yeast Production Company (GPB) produces yeast extracts on the Biotech Campus Delft. To keep the factory in good condition, they have a maintenance stop several times a year. This is also the case on July 4 to 6. The so-called dryer will be switched off and there is a chance that noise will be heard, during the day until the beginning of the evening, due to these activities. This is part of the maintenance work and is not a cause for concern.
If you nevertheless have any questions or experience nuisance, you can report this via the Environmental Complaints Number: 0800-0231341 (free and 24/7 available).