Saudi Water Partnership Company (SWPC) has invited firms to bid for the contracts to develop and operate two independent sewage treatment plant (ISTP) projects in the kingdom.

Located in Mecca, the first scheme, Arana ISTP, will have an initial capacity of 250,000 cubic metres a day (cm/d), expandable to 500,000 cm/d.

The second scheme, Hadda ISTP, will also be located in Mecca and will have an initial capacity of 100,000 cm/d, expandable to 250,000 cm/d.

According to an industry source, SWPC expects to receive bids for the contracts by 5 May.

Expected to be operational by 2028, both projects will be implemented on a 25-year build, own, operate and transfer model.

They also include treated sewage effluent (TSE) re-use systems consisting of transmission pipelines and TSE tanks.

Last year,SWPC signed a 25-year water-purchase agreement with a team comprising the local Miahona Company and Belgium's Besix for the contract to develop and operate the proposed Al-Haer ISTP in Riyadh, part of the third batch of thekingdom's ISTP programme.

The Miahona/Besix team offered to develop the project for SR1.9407 ($0.5173) a cubic metre, while the second-lowest bid, from a team comprising Spain's Acciona and the local Tawzea, was SR2.2041 a cubic metre.

The Al-Haer ISTP project involves the development of a water treatment plant with a capacity of 200,000 cm/d.

It also includes the development of a TSE reuse system that covers a 32-kilometre pipeline with a capacity of 400,000 cm/d, a pumping station and TSE reservoir tanks with a capacity of 200,000 cubic metres.