Wastewater treatment plant construction work

Tender description

The Ringsend WwTP treats most of the wastewater arising in the Greater Dublin Area. Irish Water is currently planning an upgrade to the Ringsend Treatment Plant based on the application of aerobic granular sludge technology (Nereda®) which will provide for nutrient removal, including Enhanced Biological Phosphorus Removal (EBPR). The introduction of aerobic granular sludge and EBNR will be carried out in phased upgrades of the Ringsend plant, with the aim (inter alia) of reducing the Phosphorus (P) concentration in the wastewater in compliance with relevant legislation. The maximum average capacity of the Upgraded plant will be approximately 2 400 000 Population Equivalent (PE), where 1 PE is taken as 60 g BOD/day. The Ringsend WwTP treats most of the wastewater arising in the Greater Dublin Area. Irish Water is currently planning an upgrade to the Ringsend Treatment Plant based on the application of aerobic granular sludge technology (Nereda®) which will provide for nutrient removal, including Enhanced Biological Phosphorus Removal (EBPR). The introduction of aerobic granular sludge and EBNR will be carried out in phased upgrades of the Ringsend plant, with the aim (inter alia) of reducing the Phosphorus (P) concentration in the wastewater in compliance with relevant legislation. The maximum average capacity of the Upgraded plant will be approximately 2 400 000 Population Equivalent (PE), where 1 PE is taken as 60 g BOD/day. The project will provide for the recovery of P from liquors generated from the dewatering of sludges arising at the plant, following the commissioning of the EBPR process. It will specifically provide for recovery of P from these liquors in the form of a Magnesium Ammonium Phosphate (Struvite) precipitate. The existing Ringsend plant is noted as providing for Thermal Hydrolysis, Mesophilic Anaerobic Digestion and thermal drying of sewage sludges. The tender competition will provide for the design and construction of the facility and for the operation of the facility for a period following commissioning under a Design Build and Operate form of contract. The works will provide for the recovery of struvite in a form which would comply with standards proposed by the EU STRUBIAS expert group. The new facility will be operated independently from the main wastewater treatment plant with influent sludge liquors delivered to the facility at Interface points with the existing works, and an interface for the return of the treated liquors to the existing works. The scope of the Works may be expected to include the following elements of work: — the design, construction, and operation of a P-fixation and recovery facility, — all other equipment and facilities needed including civil engineering works. The existing Ringsend WwTP is operated and maintained by a private company on behalf of Irish Water. This company will not be participating in the tender competition for the new P fixation facility as above. The Contracting Entity does not make any guarantee in regard to any contract award and/or the volume or value of works to be procured.