10000
People provided with a safe, secure and reliable source of drinking water supply
Water
Skibbereen Regional Water Supply Scheme
Irish Water was required to propose and advance remedial actions to resolve water quality issues in the Skibbereen region and remove three water supplies from the Environmental Protection Agency’s (EPA) Remedial Action List.
In partnership with Irish Water, we planned, designed and managed the construction of a rationalised regional water supply scheme centred on the treatment of drinking water at two upgraded water treatment plant sites. This will ensure a safe, secure and reliable source of drinking water supply to over 10,000 people in the region.
The historic public water supply in the Skibbereen region is derived from five separate water sources and treatment plants. There was an insufficient level of treatment at three of these plants and consequently these supplies were listed in the EPA’s Remedial Action List.
Key details
Project name
Skibbereen Regional Water Supply Scheme
Client
Irish Water
Location
County Cork, Ireland
Services provided
- Data collection and data management
- Surface water source yield assessment
- Preparation of water abstraction order documentation
- Asset data collection and asset condition/performance assessment
- Energy audits of water treatment plants and pumping stations
- Site investigation specification, procurement and management
- Site & route selection
- Flood risk assessment
- Environmental Impact Assessment Screening
- Appropriate Assessment Screening
- Invasive Alien Species surveys
- Fire safety and disability access assessments and reports
- Preparation of planning applications
- Preparation of land acquisition, wayleave and compulsory purchase order documentation
- Attendance at compulsory purchase order oral hearing
- Asbestos surveys and reports
- Detailed Design of water treatment plants and distribution networks
- Contract documents preparation
- Tender assessment
- Contract management and site supervision
Challenge
The initial challenge was to develop a project that balanced the requirements to provide improved levels of treatment while considering the longer term demand for water in the region and the yield of the existing sources. We developed two broad options; the first proposing the redevelopment of the five existing treatment plants, while the second considered the creation of a rationalised regional water supply scheme centred on the two largest existing treatment plants.
Once the project scope was defined, the next challenge was to advance the large regional scheme with multiple sites through the statutory water abstraction, planning, and land acquisition processes. Optimising the water treatment process was critical to maximise the removal of natural organic matter and minimise the production of disinfection by-products such as Trihalomethanes (THM).
Solution
Through the development of concept designs and cost benefit analysis, we identified the need to develop a rationalised regional water supply scheme centred on the treatment of drinking water at two existing plants. This then allowed the decommissioning of the remaining three existing plants.
Applying business information modelling (BIM) processes, we designed the upgrades of the retained water treatment plants using 3D design models.
Comprehensive water sampling, jar testing and THM formation potential analysis were carried out by our team to ensure the designed enhanced coagulation, flocculation and chlorination processes would sufficiently remove the pre-cursors to disinfection by-products. We proposed ultrasonic algae control to reduce the effect of algae on the treatment process.
Our team designed an extensive expansion and enhancement of the existing water supply networks to facilitate the bulk transfer of water to the supply areas where plants were being decommissioned. Robust site and route selection processes, allied with extensive environmental studies and appraisals, were critical in successfully completing statutory planning and compulsory purchase order processes.
Construction works on the €21 million capital project commenced in 2019 and were completed in February 2022. We administered the construction contract on behalf of Irish Water and provided site supervision services throughout. The three problematic public supply schemes were successfully removed from the EPA’s Remedial Action List in Q4 2021.
Project statistics
7.4
Million litres of drinking water per day provided by upgraded plants
35
Kilometres of water-mains constructed
1.45
Million litres of additional treated water storage at four reservoir sites constructed
3
Public water supply schemes removed from the EPA’s Remedial Action List