Background:
Working in partnership with the newly appointed Thames Water Network Alliance Hydrosave was appointed as specialist service provider for the delivery of the regulatory leakage target and associated Outcome Delivery Incentives (ODIs). Primarily, the framework incorporates all aspects active leak detection including networks, customer side and specialist surveys.
Thames Water is the largest supply area in England and is split in to three regional subzones these being North London, South London and West (M4 Corridor).The Thames Water supply area comprises of approximately 27,440km of water mains serving c.9 million clean water customers. Split across 1,625 DMA’s.
The Scope:
Hydrosave are responsible for the North London region which includes all District Metered Areas (DMA’s) situated within the Cities Central belt. We operate a fully managed service comprising of approximately x180 field based operatives supported by an integrated management team of x30 which includes dedicated health & safety, training, analytical and administrative roles.
Primarily daily activities are conducted from our operational offices and depot based at Deephams STW in North London where we occupy two floors within the main building and external stores. Our teams are fully integrated with Thames Water Direct Labour Organisation (DLO) and our Alliance Partners KCD which includes amalgamated people, systems and processes.
We operate a 24/7 programme with approximately 30% of activities conducted during daytime hours and 70% at night. As part of our continual improvement process we are currently implementing a plan to increase daytime working to 40% in order to increase the focus on customer side leakage, DMA cleansing and the enhanced use of acoustic and transient logging technologies.
Team Services:
Our field based operatives are transient across the operating region and are targeted towards working within DMAs which generate the best opportunity for leakage reduction as well as managing NRR and responding to event alarms. Daily survey and investigation activities comprise of:
Campaigns Plans – considers which ALC methodology will be most productive given the specific characteristics of the DMA i.e. pipe materials, connection density, pressure, ambient noise, restricted areas, commercial use, water quality risks, etc. We have developed a bespoke central repository to detail each campaign and create an ALD ‘footprint’
DMA Validation – connectivity investigations, meter verification (including flow tests), boundary valve confirmation and zero pressure tests (part or full)
Data Cleansing – property use confirmation and occupying surveys, industrial and commercial use monitoring, void and vacant property identification and billing reallocation
Acoustic noise logging – as part of the ALC campaign using specific logging technologies to best suit the application i.e. pre location noise logging ‘lift & shift’ and GPRS within DMA with high NRR, correlating noise loggers with 3 – 6 pod sensors to provide a more accurate AOI by utilising cross correlation between loggers
Seepage surveys – designated teams working with London Transport to inspect the subterranean infrastructure for visible water egress
CSL investigations – verify and validate customer side leakages, provide planning liaison and gain customer approvals for free repair service. Suite of detection activity including hydrogen gas and intrusive technologies
Trunk mains – visually inspect and check the operability of strategic sluice valves, conduct water quality risk assessment and correlation survey using high performance correlations and high sensitivity sensors i.e. Echologics ST with hydrophones and quantification tests using portable waste flow meters