Nestled within the natural beauty of the Lake District, RA Dalton Ltd were commissioned to design and install a fully engineered reed bed wastewater treatment system to support a site with variable and high‑volume effluent flows. The project required a combination of civil engineering expertise, environmental sensitivity and advanced flow‑management technology to ensure compliance, resilience and long‑term sustainability.

This case study explores how our team transformed a complex wastewater challenge into a robust, nature‑based treatment solution whilst also understanding the value and function of reed beds in modern wastewater management.

Reed beds are engineered wetland systems that use natural biological processes to treat wastewater. They are highly effective for polishing effluent from package treatment plants, reducing suspended solids, ammonia, organic load and other contaminants.

Key benefits include:

• Low‑energy operation
• High treatment efficiency
• Long operational lifespan
• Biodiversity enhancement
• Environmentally sympathetic design

In this project, the reed beds formed a crucial final treatment stage, ensuring the effluent met strict environmental discharge requirements before entering the local beck.

Before construction began, our team established a secure and fully compliant working environment by installing temporary fencing, setting up welfare facilities and preparing all required Health & Safety documentation, including detailed RAMS. We also coordinated the delivery and mobilisation of essential site machinery, including a 5‑tonne excavator, 3‑tonne excavator and 3‑tonne dumper. This thorough preparation ensured the project could progress efficiently while safeguarding both the workforce and the surrounding environment.

A key engineering challenge was controlling the periodic flow of treated effluent from the existing RBC (Rotating Biological Contactor). To achieve this, RA Dalton installed a GRP wet well capable of holding approximately 1m³ of effluent.

System Features:

• A T‑section connection to the existing outfall pipe
• Continuous diversion of effluent into the wet well
• Automatic overflow back to the original outfall once capacity is reached
• A pump unit with low‑level cut‑out and timed operation
• Full concrete encasement for structural integrity

This setup allowed the system to deliver controlled, timed batches of effluent to the reed bed system – essential for consistent treatment performance.

To ensure precise flow measurement and full regulatory compliance, RA Dalton installed a 63mm MDPE rising main leading to a purpose built flow‑meter chamber housing a MagFlow meter with an integrated data‑logging system. This setup allows the site to accurately record flow rates in litres per second, cubic metres per hour or across a 24‑hour period, providing essential data for system optimisation and ongoing environmental reporting.

The reed bed system was carefully constructed using a Landflex EP100 EPDM liner, chosen for its exceptional durability and resistance to puncture, ensuring long‑term containment and protection of the surrounding environment. Above this, the team installed Cardewmires Grit Sand, selected only after extensive permeability testing confirmed it offered the ideal balance of drainage and filtration needed for effective reed bed performance. This was complemented by a layer of rounded granular media, deliberately chosen to avoid limestone as specified, ensuring the chemistry of the treatment environment remained stable and fully compatible with the biological processes taking place. The system itself comprised two submerged‑flow treatment beds, positioned with a half‑metre buffer of unexcavated ground between them to maintain structural integrity and prevent hydraulic interference. To compensate for this separation, the overall length of each bed was extended, preserving the total treatment capacity and ensuring the system could consistently meet the required effluent quality standards.

The final stage of the project focused on completing the discharge infrastructure, which involved installing outfall pipework to link both reed beds, integrating a dedicated sample point for ongoing compliance monitoring and laying HDPE pipework both below ground and at surface level to suit the site’s layout. This was supported by the installation of a control kiosk, complete with a distribution board and ducting, to manage the system’s operational requirements. Together, these elements ensured that the treated effluent could be safely and reliably discharged to the beck, while also providing the flexibility for additional treatment beds to be incorporated in the future if required.

The completed installation now provides:

• Reliable, environmentally friendly wastewater treatment
• Accurate flow monitoring and compliance assurance
• A scalable system ready for future expansion
• A natural, low‑maintenance polishing stage through the reed beds

The project demonstrates RA Dalton Ltd’s ability to combine engineering precision, environmental stewardship and innovative wastewater solutions in sensitive locations such as the Lake District.