NHS Trust Flowing Safely With Ultralox

Legionella Compliance Case Study with Sencat

Ultralox Unit for Legionella compliance


Sencat is a Facilities Management company based in Preston, with a significant focus on the Healthcare Industry. One of their notable clients is an NHS Trust site, where Sencat plays a crucial role in ensuring the smooth and efficient operation of the facility. Hydro-X Water has been working closely with Sencat since April 2022 with our Account Manager Lloyd Hopkins providing water hygiene technical support for legionella compliance and more.


Hydro-X Water commenced taking a small number of Legionella samples from the Hot and Cold water systems in April 2022 and from this it highlighted a number of positive results due to parts of the building being vacant for prolonged periods of time.  

The issue was identified as biofilm growth in pipework located in infrequently used areas. The outlets in question were cleaned and disinfected and further sampling was undertaken from random outlets on a fortnightly basis.  

In August 2022, Hydro-X Water were asked by the client to take a more wide-spread set of samples to see if the Legionella issue was site-wide. We took 40 samples in total, 20 Pre and 20 Post-Clean, Disinfection and Flush. Whilst the majority of the results were satisfactory, their site was still getting positive Legionella results from a number of outlets.


Following a spike in Legionella positive results in late 2022 Hydro-X Water recommended the installation of a chemical dosing unit and submitted a proposal for an Ultralox 40 Dosing Unit. The Ultralox 40 was deemed to be a great fit for a site of this size especially being a low-level disinfection unit which can be used in buildings which are occupied.  

Sencat and the Trust were very proactive in tackling the spike and promptly sent instructions to Hydro-X Water to commence the unit install.  

Following the installation of the unit the Ultralox 40 levels were monitored on a monthly basis by Hydro-X Water all whilst our team of Water Technician’s continued with the fortnightly Pre and Post Legionella sampling.  

Sencat also attended site and undertook twice daily flushing of all outlets to ensure there was no stagnation occurring.   

Value added

By Mid-September we obtained our first set of results with no positives. We carried out another round of sampling in October 2023 which again came back with no positive results.  

The Trust has taken these two sets of results with the system now under control and whilst we continue with the monthly visits to check the Ultralox 40 levels we have tapered these off.

What is Ultralox40®?

Ultralox or Ultralox40® has received approval as hypochlorous acid (HOCl), the active variant of chlorine. It holds approval for use in potable water and process water, complying with Article 95 standards. It is also approved under Regulation 31 of the Water Supply (Water Quality) Regulations 2016.

This solution is well-suited for applications in water hygiene and pipework treatment, demonstrating swift effectiveness in eliminating Legionella and various other microbes. Notably, Ultralox is extensively employed in numerous NHS sites.

Supporting Your Requirements

If you are struggling with legionella compliance, and would like regular meetings to systematically work together to resolve any of your on-going site(s) needs, then look no further than Hydro-X Water. With nationwide coverage, over 35 years of experience and a team of expert technicians and innovative products available we can ensure you are in safe hands.

Contact our dedicated team of account managers on 01909 565133 or email info@hydro-x.co.uk.

ultralox unit

The Ultralox 40 Unit which is trusted across NHS sites for water hygiene compliance