The capital investment programme will include new facilities to collect water and treat waste water with the framework split into two lots covering civils and M&E work.

The water company estimates that it will spend up to £12m a year on its civils programme and £40m a year on the M&E elements.

Scottish Water intends to appoint Tier 1 contractors to support the delivery of its future quality & standards IV capital investment programme for the regulatory period starting 2015.

But this framework, depending on performance, could also be extended into a second regulatory period lifting total spend with its four favoured contractors to over £600m.

Earlier this year, Scottish Water unveiled its two alliance partners, who will oversee and deliver the bulk of its spending over the next six years.

Caledonia Water Alliance – a Morrison Utility Services and Aecom – and BBV Alliance – Black and Veatch and Byzak will work with Scottish Water  to procure tier one contractors to support the work pipeline.

Firms have until 4 July to return PQQS, which can be obtained from the Scottish Procurement Portal.