Legionella risk assessment in Southampton

Updated 7 September 2026

Southampton's port, its large NHS teaching hospital estate, and its cruise terminal activity create specific demand for legionella management in hospitality and healthcare. The city's shoreside cruise passenger facilities need the same controls as any commercial premises, and the port's large warehouse and welfare block estate adds further industrial demand.

Local water supply

The mains water supplier for Southampton is Southern Water (Southern 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 Southampton area is classed as Hard on the Drinking Water Inspectorate hardness scale (around 220 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 in the South East

The most recent regional surveillance figures recorded 100 confirmed cases of legionellosis in the South East in 2023.

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

Typical cost in Southampton

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

• Small premises, mains-fed only, no storage: £150 to £250
• Typical office or shop with a hot water cylinder: £200 to £400
• Care home, hotel, or school with stored hot and cold water: £400 to £800
• Premises with a cooling tower or evaporative condenser: from £800, often much higher

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.

Legionella enforcement in the South East 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 Southampton itself; the cases below are the most recent recorded elsewhere in the South East 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:

Sentinel Health Care Limited, 2020 (Care home) — fined £150k. A 56-year-old resident died of Legionnaires' disease contracted at a Hampshire care home in 2020. In the CQC's first legionella prosecution, the company admitted failing to provide safe care and treatment.

Reading Borough Council, 2016 (Care home) — fined £100k. A 95-year-old resident died in 2012 of legionella pneumonia at a council-run intermediate-care home, where the strain in his room's washbasin tap matched his infection. Monitoring and flushing had been left to an inadequately trained handyman with no cover.

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 Southampton

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

• Work for a company registered with the Legionella Control Association (the LCA is the main UK trade body for water hygiene)
• Hold a City & Guilds or equivalent qualification in legionella risk assessment
• Can provide references from similar premises in the Southampton area
• Will quote against a clear scope (number of outlets, inclusion of hot and cold surveys, whether sampling is included)

Legionella testing labs covering Southampton

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 Southampton itself, so the nearest UKAS-accredited labs are listed below — all accept postal samples, and posted sampling is how most premises use them:

• Feedwater Laboratories (UKAS no. 2234), turnaround ~10 days, from £82.68 per sample
• Eurofins Water Hygiene Testing UK Limited (UKAS no. 9658)
• ALS Environmental (ALS Laboratories (UK) Limited) (UKAS no. 1314)

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 Southampton

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

• Landlords and rental properties
• Offices
• Care homes
• Hotels
• Schools
• Dental practices
• All building types