Secondary Disinfection Options

What is secondary disinfection?

Primary disinfection in water systems is the application of chemicals to kill or inactivate waterborne microorganisms, such as Legionella. Secondary disinfection is the maintenance of residual disinfectant in the water to prevent their regrowth.  The disinfectant achieves this by killing potentially harmful organisms as it moves through the water pipes. It is particularly important in buildings with vulnerable residents or customers, for example care homes and hospitals.

At Rock Compliance, we are always upfront and honest about any work we recommend or undertake. Our key aim is to minimise risk and eliminate the need for secondary disinfection. If you already use us as your water hygiene service provider, chances are that your systems do not need secondary disinfection. This is because we work with clients to minimise risk by resolving all non-conformances. We support our customers to simplify water systems, engineering out risk areas, so lessening the need for secondary disinfection. In this way, over time risk is reduced.

If your building is experiencing any of the issues below, don’t wait until the problem gets out of hand – contact us now to talk about secondary disinfection:

  • Consecutive out-of-specification temperatures
  • Loss of system primary control
  • Consistent Legionella positives
  • Current secondary disinfection system is ageing and needs to be replaced
  • Current secondary disinfection system is unsafe
  • Current secondary disinfection system is not working properly


Putting safety first

Ensuring the wellbeing of your staff, customers and building users is an absolute priority. Our solutions may not be the cheapest on the market, but they are the safest, providing an increased level of control that minimises risk and delivers compliance.

There are numerous ways water can be disinfected continuously, such as hypochlorous acid, chlorine dioxide, silver peroxide, hydrogen peroxide, copper/silver ions in liquid form. Each option has its benefits. Our engineers will determine the most efficient and technically correct one for your business and water system.

Whichever secondary system is installed, safety is the highest priority. This is particularly evident in the case of domestic water, where extra care needs to be taken in designing a dosing system to ensure harmful chemical cannot be overdosed, creating a chemical health concern. There are also regulations governing which chemicals can be added to potable water, with limiting concentrations.


Rock Compliance van

The Rock Compliance Oxidation Station

Our business is built on three key promises we make to our customers: to minimise risk, to deliver compliance, and to make it simple.

We are always looking for the most effective technology to help us deliver on these promises. And if the right product isn’t already on the market, we’ll develop it ourselves!

Our plug-and-play Oxidation Station was designed to provide eight levels of control, with fail-safe protection against the risk of dangerous overdosing:


Level of Control Feature Why is this a necessary element to the Oxidation Station?
1 Proportional flow Only doses chemicals when the water is flowing.
2 Overdose cut-out – ion selective probe Detects presence of the specific chemical being dosed and cuts off the pump if the chemical reserve is too high.
3 Data logging/graphing/local alarms (visual and audible) Enables the site staff and/or local engineers to see the equipment is working and trouble-shoot any issues.
4 Remote monitoring and control 24/7 web-based monitoring – sending data and alarms to engineers off site, allowing them to alter settings remotely and shut the unit down completely.
5 Degassing head on dosing pump Prevents air-locking on the chemical pump to prevent unnecessary loss of control and the need/cost of call-outs.
6 Tank level monitoring Monitors chemical levels remotely and ensures the chemical is topped up and never runs out, leading to loss of system control.
7 Maintenance contract Proactive and preventative maintenance of the unit.
8 Comprehensive compliance monitoring contract A comprehensive package to provide compliance with HSG274 and/or HTM 04-01, including regular residual checks around the building to ensure the chemical is reaching all areas and protecting employees and guests.
Secondary Disinfection Options

Rock Compliance van

Copper and Silver Ionisation

After many years of trialling and assessing non-chemical devices that control Legionella without harming the environment, the one system that stands out as an alternative option to chemicals is our Copper and Silver Ionisation.

Working in conjunction with our partner, Necon Technologies, Rock Compliance can provide a bespoke quotation suitable for the treatment of water on your site. This solution generates a constant supply of ions at a predetermined rate and delivers them in a highly controlled and systematic way, in line with proportional control.

The rate at which the ions are released is automatically maintained by a reliable and easy-to-operate control unit. The ultrasonic flow meter or water meter (depending on the application) provides the means of dosing proportionally, meeting the requirements of HSG274 part 2 and HTM 04-01. The accurate dose-rate control system then maintains precise ion levels, providing residual protection and prevention of recontamination.

This solution is particularly popular with our healthcare clients and can be found in many hospitals across the country.  There are several reasons for this:

  1. A long-term residual remains in the system for ongoing water disinfection
  2. It’s effective in dead legs (pipework can be difficult to trace in older buildings with no schematics, causing possible dead legs)
  3. It eradicates the need for chemicals to be brought to site, reducing COSHH handling concerns and chemical deliveries
Rock Compliance Remote Temperature Monitoring
Customer Case Studies brochure

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Download our case study booklet to learn more about our many successful compliance projects throughout the UK

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Whether it is an issue of compliance, an investment decision, or you are just not quite sure whether your existing provider is giving you what you want, please contact us.  We will be happy to give you advice on how to create low risk, compliant water systems, ensuring spend is minimised and predictable.

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