Ultrafiltration system supports drain water treatment at Van Leeuwen Westland

Water quality is becoming a central factor in modern greenhouse production, driven by stricter discharge regulations and the need for stable cultivation conditions. At the Dutch pot and bedding plant nursery Van Leeuwen Westland, this led to the implementation of a new system for treating and reusing drain water.

The family-owned company, founded in 1977, operates around 26 hectares of greenhouse production. Water management plays a key role, with large volumes circulating through ebb-and-flow and sprinkler irrigation systems. During peak periods, up to 1,800 m³ of water per day is pumped through parts of the facility, with most of it returning as drainage water.

The system is complemented by a belt filter for pre-filtration. © Van der Ende Group

The project was initiated due to limitations of the existing UV disinfection system, which had become less reliable over time. Together with installer Haket and supplier Van der Ende Group, the company evaluated alternative technologies. The decision-making process, including technical and economic considerations, took more than two years.

The final solution is based on ultrafiltration technology. A Kathari UF-30 system was installed to treat multiple incoming water streams with a capacity of up to 100 m³ per hour. The system is complemented by a belt filter for pre-filtration, which removes coarse particles and supports the performance of the filtration membranes.

The final solution is based on ultrafiltration technology. © Van der Ende Group

In addition to the filtration unit, the water infrastructure at the nursery was significantly upgraded. This included the installation of additional buffer silos, a new high-capacity water unit, and modifications to enable the separation and controlled handling of different water streams. These measures are intended to stabilise water quality and improve operational reliability.

According to the company, the choice of ultrafiltration was driven primarily by its ability to physically remove pathogens such as bacteria, fungi, and viruses, while retaining nutrients in the water. Energy consumption and operational costs were also considered in the evaluation.

The broader context for the investment is the increasing importance of closed water systems in greenhouse horticulture. Regulatory requirements limit discharge, making effective treatment and reuse of water essential. Reliable filtration technologies are therefore seen as a prerequisite for sustainable production.

The system was installed in December, requiring temporary interruption of irrigation operations. Following commissioning, the system is currently being monitored and fine-tuned. The company expects that once fully stabilised, the installation will contribute to more secure and future-oriented water management.

From left: Ronald Haket, Bart van Leeuwen, Ruud Schulte. © Van der Ende Group