A survey of the wastewater outfalls operated by Guernsey Water showed that the existing Long Sea Outfall (LSO) was in a poor condition and could fail at any time, while the Short Sea Outfall (SSO) was over a century old and in need of replacement.

Royal HaskoningDHV was engaged by Van Oord to provide a tender design for the replacement of both the onshore and offshore Belle Greve Outfall works. This design allowed Van Oord to competitively price the tender submission to Guernsey Water and win the project. Following award, Royal HaskoningDHV was commissioned to undertake the detailed design.

Our team provided the detailed design for a 1.6km SSO and 2.4km LSO to Van Oord to enable delivery of the project on time and within the £15million budget.

This project not only mitigated a potential outfall failure, but has lengthened the outfalls so that wastewater will be discharged into deeper and faster-flowing water, improving local water quality.  This allows Guernsey Water to meet the long-term needs that will be required under future water quality legislation, securing a major element of the waste water treatment facility on the island for years to come.