Legionella Risk Assessments in Bushey

Legionella Risk Assessments in Bushey: what is different here

What the mains water in Bushey is like

Bushey is supplied by Affinity Water's Borehamwood/Bushey zone. Its 2025 report records 216 temperature samples with a mean of 14.3°C, a low of 6.8°C and a high of 23.9°C. Legionella bacteria multiply in water between about 20°C and 45°C, so in a warm spell the cold supply can arrive at or above the bottom of that range.

That makes the route of cold pipes more important: a cold feed running through a warm airing cupboard, beside a hot pipe or across a hot loft has less margin than it would in winter. The same report gives total hardness of 340 mg/l, and scale inside cylinders, shower heads and taps gives bacteria somewhere to settle.

Loft tanks and stored hot water in older Bushey houses

Many of the bigger and older houses in Bushey still run a vented system, with a cold water storage tank in the loft feeding a hot water cylinder. Others have been converted to an unvented cylinder during an extension or a new bathroom. Either way, stored water is where most of the risk sits. We check that a loft tank has a fitted lid and insulation, is free of debris and is not warming up; that the cylinder reaches and holds 60°C; and how long hot taps take to run hot at the furthest outlets.

A small flat with a combination boiler stores almost no water, and the assessment is correspondingly short.

Spare bathrooms and HMO wash basins

A large house on Bushey Heath or around Hartsbourne may have three bathrooms but be let to a family that uses one. The others become low-use outlets, and so does a shower in a garage or an outside tap on a long pipe run. In a shared house the outlet count rises further: Hertsmere's draft 2026 standards ask for a hand wash basin in every bedroom where practical and another bathroom for every five people.

The assessment lists each little-used outlet and sets a flushing routine that tenants can realistically follow.

Empty houses between Bushey lets

Water standing in pipes and tanks during a void is a known risk. If a Bushey property has been empty for some weeks, it should be flushed before the next tenants arrive, running every hot and cold outlet and the shower heads until the water is at temperature. If the property is being decorated or tiled while empty, we can fold the flushing into those visits and note it on the record.

What the law asks of a Bushey landlord

The duty to assess and control the risk comes from health and safety law and HSE's approved code of practice. HSE says landlords do not need a legionella test certificate, most can assess the risk themselves, recording the findings is not always required, and there is no fixed review date. Sampling is rarely needed. Hertsmere, the council for every address from Bushey Village to Little Bushey and Merry Hill, goes further for licensable HMOs in its draft July 2026 standards: they expect a legionella risk assessment where one is required, reviewed after any change to the water system, a change of tenants or maintenance work.

An assessment written by us gives you a record of what was checked and when, which helps when a tenant, agent or the council asks.

Official sources

• Affinity Water: water quality report 2025, Borehamwood/Bushey zone (AF049)
• HSE: legionella, landlords' responsibilities
• Hertsmere Borough Council: draft amenity standards for HMOs 2026 (no additional licensing scheme)
• ONS Census 2021 via Nomis: accommodation type, Bushey Heath, Bushey North, Bushey Park and Bushey St James wards (TS044)

Last reviewed October 2026 by EliteShires Property Services.