Greenhouse farmers warned: avoid water pollution when using screening agents
Greenhouse businesses applying screening agents to protect crops must prevent pollution of surface water. Chalk residues can harm aquatic life and disrupt ecosystems, leading to enforcement actions and fines. Here’s what entrepreneurs need to know to stay compliant.
| Key Data Point | Details |
|---|---|
| Substance | Screening agents (often chalk-based) |
| Risk | Pollution of surface water, ecological disruption |
| Enforcement Authority | Delfland Water Board |
| Legal Basis | Article 7.20a of the Delfland Water Board Byelaw (Wsv) |
| Penalty | Order subject to penalty payment for violations |
| Alternatives | Special glass, external screens, approved agents without harmful additives |
| Prevention Measure | Collect and process chalk water to avoid visual pollution |
The Delfland Water Board is responsible for managing water quality and enforcing regulations to protect surface water in its jurisdiction. It monitors compliance with bylaws, such as the Wsv, to prevent pollution and maintain ecological balance in water systems.
Openrijk has no cookies or ads
But could use some support
Read the full translated article below
Screening agents: what should greenhouse businesses watch out for?
The sun is getting stronger, so many greenhouse businesses will soon be applying screening agents to their greenhouses. Applying a white layer is permitted, but this must not lead to pollution of surface water. In this article, entrepreneurs can read what they need to consider when using screening agents.
What are screening agents?
Screening agents, which often contain chalk, protect crops in the greenhouse from intense sunlight. The advantage is that crops do not get damaged. However: when screening or chalk agents are applied to the greenhouse, there is a risk that residues end up in the ditch. This can happen due to careless work, but also if rain washes off a greenhouse roof that is not yet dry.
How screening agents pollute surface water
Chalk discharges into the ditch have direct consequences for the quality of surface water. For example, the water may become more acidic, disrupting the ecological balance. In addition, chalk water turns the water milky white; the chalk particles eventually settle on the bottom and on aquatic plants. Due to this haze and sediment, sunlight cannot penetrate the water as well. As a result, aquatic plants produce less oxygen, which is also harmful to fish and other underwater life. Moreover, screening agents can damage the gills of fish.
Active enforcement
Because chalk discharges are harmful to the quality of surface water, we actively enforce against these discharges. This is done under the Delfland Water Board Byelaw (Wsv). Article 7.20a of the Wsv states that discharges of screening and chalk agents into surface water must not cause visual or thermal pollution. If our inspections reveal a white ditch or if we detect a discharge of non-visible screening or chalk agents, we will impose an order subject to a penalty payment.
Alternatives and careful handling
Although chalk is widely used, there are alternatives, such as special glass and external screens. If you, as an entrepreneur, do use chalk or other screening agents, only use approved agents without harmful additives. When applying or removing the chalk, collect all the chalk water and process it in such a way that no visual pollution of the surface water occurs.