Water quality for inset appointees and NAVs

An inset appointment makes you the water undertaker for your site, with the same duties to the people you supply as the company you replaced. The Drinking Water Inspectorate regulates your supply as a public one from the first property.

You are a water company now

Ofwat grants new appointments and variations under the Water Industry Act 1991. Once granted, you are the appointed undertaker for that area, and the duties that come with it are not scaled down to match the size of your business. A development of two hundred homes is regulated on the same basis as a city.

In practice the Water Supply (Water Quality) Regulations apply to you in full: a risk-assessed supply system, a regulatory sampling programme, analysis by an accredited laboratory, notification of events, and annual returns to the Drinking Water Inspectorate. Most new appointees are small teams, and the water quality function is more often bought in than built.

What has to be in place before you supply

None of this can be arranged after the first occupation. It belongs in the programme alongside the civils.

A satisfactory risk assessment – Of the whole supply system, from the bulk supply point through to the consumer tap.

A competency assessment – DWI needs to be satisfied that the appointee can actually run a public supply.

A sampling programme – Locations, parameters and frequencies agreed and resourced before anyone moves in.

An accredited laboratory – Analysis to ISO 17025, with the chain of custody to match.

Event procedures – Who decides, who notifies, and how fast, written down before it is needed.

Operational cover – Somebody competent reachable when a result comes back on a Friday afternoon.

The bulk supply interface is where quality is won or lost

Most inset supplies begin at a bulk supply point from the incumbent. The water arriving is compliant when it arrives. What happens to it afterwards is yours: disinfection residual, water age and the condition of a brand new network all sit on your side of the meter.

Agree what is measured at the interface, and by whom, before the first handover. Arguments about whose water produced a particular result are considerably easier when there is a baseline that both parties accepted at the time.

Sampling and analysis

Phased developments have a water quality problem designed in

A network built for a thousand homes and currently serving sixty has a turnover problem. Water sits in mains sized for an occupancy that does not exist yet, disinfection residual decays, temperatures climb through the summer, and sample results begin to drift long before anybody has done anything wrong.

The controls are well understood: phased commissioning, targeted flushing, strategic sampling, and sometimes temporary network configuration to keep water moving. They work when they are planned into the build programme, and they are expensive and disruptive when they are retrofitted after a failure.

How we support new appointees

The whole water quality function, or the parts of it you do not want to carry in-house.

Competency assessment support – Evidence, procedures and documentation in the form DWI expects to see.

Regulatory sampling programmes – Designed, scheduled and delivered, with UKAS-accredited analysis behind them.

Drinking water safety plans – Risk assessment of the supply system from end to end.

Bulk supply interfaces – Handover water quality and baseline monitoring at the point of connection.

Commissioning and stagnation – Low turnover, residual decay and disinfection on phased sites.

Events and annual returns – Investigation, reporting, and the returns themselves.

A water quality function you do not have to build.

Talk to us about competency assessment, a sampling programme, or support through your first year as an appointee.

For any enquiries or questions please call: 01707 527 069