Sewage digesters

Tender description

Yorkshire Water (YW) manage the collection, treatment and distribution of water in Yorkshire, supplying around 1 240 000 000 litres of drinking water each day. At the same time collecting, treating and disposing of about one billion litres of waste water safely back into the environment. The contract will be part of the Asset Integrity team’s delivery of process safety works. A range of specialist technical services will be selectively employed across YW’s estate to support applications and processes for raw water, treated water, waste water, sewerage treatment and clean and sewer networks. These services are vital to supporting safety and compliance across YW’s business. This directly links to the business commitments and performance measures contained within Yorkshire Water’s business plan. YW therefore intends to establish a framework for Nitrogen Purging and Digester Maintenance. Yorkshire Water are looking to establish a framework covering services relating to Nitrogen Purging and Digester Maintenance. Broadly the scope falls in to 3 main areas. 1) Gas purging of primary sludge digesters, gas holders and associated pipework within the current asset profile; 2) Interior cleaning of digesters, pre-and post-digestion vessels including consolidation, buffer, pathogen kill, pre-dewatering and storm tanks, lagoons, ASP lanes and ditches, where cleaning and separation of materials is required; 3) Carrying out refurbishment works to digesters and gas holders that includes decommissioning and re-commissioning, repairs and recoating of any concrete, using approved coatings to seal concrete, repair and or replacement of steelwork, design works to facilitate refurbishment, repair and or replacement to any pipework (sludge and gas) and sign off/certification to finalise works. During the course of the contract life the services will support AMP7 delivery period where there will be an expected annual spend of c. 500 000 GBP for at least 5 years. The contract will be single source with the successful supplier being able to provide all the required services across the entire range of YW’s assets. The works will consist of reactive works and larger planned schemes.