Scottish Water - Delivery Assurance Group: performance progress report - quarter four 2022-2023

7. Progress in delivering SR15 Completion Projects

SR15 completion projects are reported in each of the water and wastewater portfolios in Sections 4 and 5 of this report. For clarity, all completion projects are summarised in Section 7. By way of recap, there are two categories of SR15 completion projects:

• Delayed Projects – projects that were expected to complete by the end of SR15 but were impacted by Covid-19, scope change, construction risk and third-party risk
• Planned Projects – projects that commenced in SR15 but were always expected to complete during SR21

Table 1 below summarises the current status of each category.

By way of further explanation:

Delayed Projects

At the end of Q4 2022/23 we had planned to have 80 of the 86 delayed SR15 projects through acceptance (Table 1). 21 have still to achieve Gate 100 acceptance. 4 of these are now forecasting acceptance in Q1 with a further 3 in Q2. A further 7 projects are forecasting completion in the remainder of 2023/24. 2 projects (Mannofield WTW and Easdale Cottages) forecasting acceptance later in the period to align delivery with other planned work in the programme.

The reasons for reforecasting:

• The delivery of 5 projects has been reforecast due to third party issues.
• The delivery of a further 14 projects has been reforecast due to construction risks being realised. An example of this is at Londornoch WTW where work has been extended due to both the volumes of sludge encountered and re-sequencing of the contractor programme to allow the new sludge balance tank to be commissioned prior to emptying sludge lagoon No.2.
• 1 project has been reforecast as additional scope is required to complete the project.
• 1 project, Easdale - Seaview Cottage ST, has been delayed pending confirmation of the proposed solution for the nearby Clachan Balvicar WwTW where trials to provide additional filtration/UV treatment to protect the receiving water are currently ongoing.

The drought resilience project at West Lewis, which had previously been delayed due to the discovery of a crannog and other third-party issues, is now on site and in construction.

3 delayed projects are yet to start on site. These are:

• Rockcliffe BW - Improvement to Sufficient Status where there has been significant community engagement on the location of the proposed works to minimise impact. Planning and land issues are now being moved forward. The most recent forecast delivery acceptance date of Jan 2026 is of concern to SEPA as the interim measures will remain in place for a further bathing water season. Chemical dosing is in place to protect the bathing water until the new works is constructed. The project is forecast to achieve G90 in Q2 and to start on site in Q4.
• Roberton WTW where the operational solution trialled to provide pH correction and coagulation has not been successful and a new project has been developed. The project is forecast to achieve G90 in Quarter 3 and to start on site in Q4. Acceptance is forecast in 24/25 Q3.
• Boardhouse WTW where the proposed scope was found to be undeliverable. On investigation considerable siltation was found at the inlet pipe and this will be addressed before any screening at the inlet is considered. The project is forecast to achieve G90 in Q3 and to start on site in Q4. Acceptance is forecast in 24/25 Q2.

Planned Projects

Two projects achieved acceptance in Q4. 43 projects have now achieved Gate 100 acceptance against a target for Q4 2022/23 of 52. 10 projects have been impacted by delays. 2 of these projects are forecasting completion in Q1 with a further 3 in Q2. The remaining projects, except for Edgehead St, Water of Leith UIDS - batch 7 - Longstone CSOs and Kirkmichael WTW, are forecasting to be complete during 2023/24.

Kirkmichael WTW was returned to the plan stage as the operational solution experienced some difficulty –however the output is likely to be closed as a consequence of the operational solution being implemented, and further investment needs at the site considered as part of the SR21 management approaches. Upperton (Longriggend) WWTW is going through a scope review process. The project is forecast to start on site in September this year.

4 Planned projects are yet to start on site. These are:

• Sanday WTW achieved Gate 80 in 22/23 Q3. Detailed design is ongoing, and the project is forecast to start on site in September this year. The project is forecast to achieve G90 and start on site in Q3. Acceptance is forecast for 24/25 Q3.
• Edgehead Septic Tank is going through the estimating process. Technical review and design acceptance have been agreed. The project is forecast to start on site in Q1. Acceptance is forecast for 24/25 Q3.
• South Uist WTW New Source is still under investigation to confirm the requirement for a new source. Water Quality sampling for potential new sources is ongoing, alongside discussions with SEPA, and a hydraulic model build has been scheduled to investigate whether more water can be transferred from Benbecula. The work at Stoneybridge WTW to improve water quality is likely to deliver the SR15 outputs by August 2023 and the requirements for a new source considered in the round with future investment needs and priorities.
• Upperton (Longriggend) WWTW is forecast to start on site in Q2, ahead of baseline (Q3).