Yorkshire Water has awarded a contract for nitrogen purging and sludge digester maintenance services worth an estimated £3 million.

The water company has established a framework for nitrogen purging and digester maintenance - the contract will be part of the Asset Integrity team’s delivery of process safety works.

Scope of the works, which will consist of reactive works and larger planned schemes, falls broadly in three main areas:

Gas purging of primary sludge digesters, gas holders and associated pipework within the current asset profile.

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.

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 the AMP7 delivery period with an expected annual spend of around £500,000 for at least 5 years.

The contract is single source - the successful supplier will provide all the required services across the entire range of Yorkshire Water's assets.

GTS Nitrogen Services Ltd has been awarded the contract, one of three firms in the bidding for the work.