PROJECT
Dunstaffnage Castle Treatment Works, Scotland
CLIENT
Historic Environment Scotland
TIME FRAME
April – June 2023
PROJECT BRIEF
Historic Environment Scotland required the replacement of an ageing septic tank serving Dunstaffnage Castle with a modern, compliant sewage treatment solution. The works were located within the grounds of a Scheduled Monument, adjacent to a sensitive coastal environment and shellfish harvesting waters.
The project involved installing a new packaged sewage treatment plant with UV disinfection, upgrading associated drainage infrastructure, and constructing a new treated effluent outfall to Dunstaffnage Bay.
All works were undertaken within a live, operational heritage site, requiring careful planning to protect historic fabric, minimise environmental impact and maintain public access throughout the construction period.
PROJECT KEY POINTS
- Replacement of an existing septic tank with a modern sewage treatment plant and UV disinfection chamber.
- Installation of new pipework, manholes and inspection chambers.
- Construction of a new treated effluent outfall to Dunstaffnage Bay.
- Limited intertidal works undertaken during low spring tides to install the final section of the outfall.
- Works delivered within the grounds of a Scheduled Monument and live visitor attraction.
- Strict access, storage and waste-management controls.
- Close coordination with Historic Environment Scotland and full compliance with CDM 2015.
Sustainability & Assurance
Environmental protection and sustainability were central to the delivery of this project. The new treatment system significantly improved wastewater performance, providing enhanced protection of controlled waters through upgraded treatment processes and UV disinfection prior to discharge.
Outfall works were carefully programmed around low spring tide windows to minimise interaction with water, with only the final section of the outfall installed below the waterline. All intertidal activities were tightly controlled and undertaken in accordance with SEPA and NetRegs guidance, with pollution prevention measures in place at all times.
Additional measures included:
- Careful management of excavations to prevent contamination or migration of materials.
- Daily removal of waste and strict control of material storage.
- Noise, dust, and pollution controls to minimise impact on visitors, staff and wildlife.
- Continuous monitoring and coordination with the Client throughout the works.
All construction activities were delivered in line with approved drawings, British Standards and a robust Construction Phase Plan, supported by full quality assurance and handover documentation.
PROJECT OUTCOME
The project successfully delivered a modern, compliant sewage treatment solution that significantly improved environmental performance while respecting the historic and archaeological sensitivity of Dunstaffnage Castle.
The works were completed safely, efficiently and in full accordance with Historic Environment Scotland's requirements, ensuring long-term resilience of the site's wastewater infrastructure and enhanced protection of the surrounding environment.
PROJECT SERVICES
