Legionella risk assessment in Plymouth

Updated 7 September 2026

Key points

  • Legionella risk assessments in Plymouth are required for any non-domestic premises with a water system that can aerosolise water
  • Your mains water supplier is South West Water
  • Typical cost: £150 to £600, depending on the size and complexity of the water system
  • Use our cost calculator for a specific estimate

Plymouth's legionella risk assessment demand is driven by the University Hospital Plymouth estate, the city's hotel and leisure sector, and its naval and dockyard facilities. The dockyard's welfare and accommodation blocks, together with its workshops and process water systems, produce a level of industrial demand unusual for a city of this size.

Local water supply

The mains water supplier for Plymouth is South West Water (South West Water website). The mains supply is treated and controlled by the supplier, so your legionella duties begin where the water enters your premises. Anything downstream of the boundary stop tap (storage tanks, calorifiers, pipework, outlets) is your responsibility.

Water in the Plymouth area is classed as Soft on the Drinking Water Inspectorate hardness scale (around 35 mg/l as CaCO3), according to MyTapWater water quality data (single source - unverified). Harder water lays down scale inside calorifiers, cylinders, and mixing valves, and scale gives legionella a foothold while blunting temperature control, so in hard-water areas descaling and inspection belong in the written scheme of control. Check your supplier's postcode water-quality checker for the figure for your exact supply zone.

Legionnaires' disease: the national picture

UKHSA does not publish a separate surveillance figure for the South West, so no regional number is shown here. The most recent national figure recorded 472 confirmed cases of legionellosis across England and Wales in 2024 — the England & Wales average context, not a count for this region.

472Confirmed cases, England & Wales, 2024
not publishedSeparate figure for South West

UKHSA states figures explicitly for only a handful of regions; a full region-by-region table is not published, and surveillance counts only laboratory-confirmed, reported cases, so the national total is a floor rather than the true number of infections. The full picture, with the trend since 2017, is on the Legionella Data Index. The absence of a regional figure changes nothing about your own duties: a non-domestic water system in Plymouth still needs a risk assessment, a control scheme, and the records to show the scheme is being followed.

Typical cost in Plymouth

Legionella risk assessment costs in Plymouth depend more on the water system than on the location. A rough guide:

Cooling towers drive the cost up because they are notifiable to the local authority under the Notification of Cooling Towers and Evaporative Condensers Regulations 1992, and they need quarterly sampling and extensive cleaning. Get a tailored estimate with our cost calculator.

Free legionella risk assessment template

A structured Word document following the five-step approach in ACOP L8. Covers risk identification, written scheme, monitoring, and records. If it isn't written down, you can't evidence it.

Follows ACoP L8 and HSG274 Part 2. Free. No spam.

Legionella enforcement in the South West England

Prosecutions for legionella failings are usually brought under the Health and Safety at Work etc. Act 1974, whether by the HSE, a local authority, or (in Scotland) the Crown Office and Procurator Fiscal Service. No case in our tracker is recorded in Plymouth itself; the cases below are the most recent recorded elsewhere in the South West England, shown as regional context rather than local history. They are drawn from our legionella enforcement tracker, which records each one against its primary source:

Royal United Hospitals Bath NHS Foundation Trust, 2018 (Healthcare) — fined £300k. A cancer patient died in 2015 after exposure to legionella in a hospital ward annex. A separate water loop feeding the annex, opened in 2009, had never been temperature-checked or tested. The strain was not matched to the system, so the charge was exposing patients to risk.

The failings behind these cases are consistent: no suitable risk assessment, no written scheme of control, monitoring not carried out, or records that could not show the controls happened. The full dataset is on the enforcement tracker, and legionella fines and prosecutions explains how the courts approach sentencing.

Find a legionella risk assessor in Plymouth

We are building a directory of qualified water hygiene assessors in Plymouth and across the UK. In the meantime, look for assessors who:

Legionella testing labs covering Plymouth

Routine temperature monitoring is done on site, but where your risk assessment or written scheme calls for water sampling, the samples go to a laboratory for culture. None of the UKAS-accredited laboratories in our directory is based in Plymouth itself, so the nearest UKAS-accredited labs are listed below — all accept postal samples, and posted sampling is how most premises use them:

Methods, turnaround times and published prices for the full directory are compared on the legionella testing labs page. Sampling is not a substitute for day-to-day control: a clear result records what was found at that outlet on that day, it never certifies a system as safe, and it sits alongside the routine checks in your written scheme of control, not instead of them.

Building types in Plymouth

Different building types have specific legionella considerations. Browse the guides most relevant to Plymouth premises:

Related water hygiene products and services from trusted UK providers will appear here.

Free legionella risk assessment template

A structured Word document following the five-step approach in ACOP L8. Covers risk identification, written scheme, monitoring, and records. If it isn't written down, you can't evidence it.

Follows ACoP L8 and HSG274 Part 2. Free. No spam.

Important This page is general guidance only. Legionella risk varies with the specific water system, its use, and the people exposed to it. You should consult a competent legionella risk assessor for advice on your premises. LegionellaCheck is an independent information service and is not affiliated with HSE, UKAS, the Legionella Control Association, or any water hygiene company. This site does not provide medical advice. If you suspect Legionnaires' disease, contact NHS 111 or your GP.