Ensuring a safe and effective bounce-back

Now that the COVID-19 pandemic is being brought under control and lock down measures are easing, many organisations will be resuming full operations. However, it is essential to ensure that process and purified water systems are operating correctly following any shutdown or reduction in use.

Organisations in a wide range of sectors from manufacturing to scientific research have had to scale back or halt operations in recent months. At the start of the lockdown it was unclear for how long it would be in place, so each facility had to make a decision on what level of activity could or should be maintained and so the degree of shutdown that was required. Some chose to close their sites completely, halting all activity and temporarily decommissioning plants and equipment. In other cases, a ‘stand-by’ approach was adopted where systems were kept running at a minimal level.

While some processes will be simple to restart, sites with purified water systems must take care to ensure that they are recommissioned or returned to normal use safely and that they are performing as designed. Failure to do so can have serious consequences. For manufacturing or industrial businesses, it can lead to issues with the products and even risks the health and safety of employees and customers. For laboratories in research facilities and universities that rely on pure water for everything from cleaning to use as a reagent, a problem with the quality of the supply can impact test results.

The approach adopted will determine what steps should be taken to ensure a safe and effective return.

Systems that remained operational

Some will have taken the decision to keep the purified water systems running to continually recirculate the water. This prevents stagnation and with the water circulating through the treatment units, the quality of the water is more likely to be maintained. However, the temperature of the water retained in the system may have risen significantly. This is because parts of the system, such as the pumps used for recirculation can transfer heat into the water and without water being drawn off and replaced from the lower temperature supply, the heat builds up. Also, the warm weather that the UK experienced during the lockdown period meant that ambient temperatures were also higher, contributing to this effect. Where the water temperature rises above 30°C, it provides an environment where microbes can grow quickly. This means that while other parameters of the water, such as conductivity, might meet the specified standard, the level of biological contamination may be higher.

Generally, where the system has remained operational there should be minimal issues returning it to full operation. We recommend that the system is flushed and fully sanitised. It is also advisable to change all the consumables within the system, such as the filters, and check that items such as UV lamps have not reached the end of their recommended service life.

Decommissioned systems

If a full shutdown was required and the water system was switched off and left, there are a number of potential issues. Water left in the tanks and pipework will have stagnated, providing an ideal environment for the growth of micro-organisms. It is also likely that biofilms will have formed on surfaces within the system. These can be extremely difficult to remove and will protect micro-organisms from disinfection chemicals. The presence of biofilms will often not be picked up automatically, which means that unless the system is thoroughly heat sanitised, the micro-organisms can quickly regrow, increasing the likelihood of microbiological by-products, such as endotoxins. Even if the system was drained, small amounts of water left can lead to a build-up of contaminants.

Furthermore, it is possible that leaving the system inactive for an extended period of time may have allowed some deterioration of the components. This may shorten the life of certain elements and may require remedial work to be carried out.

Where the system has been left, it is recommended that it is flushed, fully sanitised and all consumables replaced. However, due to the potential issues that the prolonged shutdown may have caused it is recommended that support and guidance is sought from the system’s service contract provider.

How can Veolia Water Technologies help?

For customers that need support in returning to normal levels of operation, we can assist in a number of different ways. If you have questions or concerns about the system, our expert team can offer support over the phone. They can provide advice on the best approach based on the technologies and equipment you have in place as well as how the system has been operated over recent months. In many cases the recommended actions can be carried out by your in-house team. Where further support is required our engineers can visit the site to evaluate the system and advise on the best course of action to ensure a complete and safe restart of operations.

The events of the last three months and the steps taken in response, are unprecedented. The extent and urgency of the reduction in activity meant that decisions had to be made quickly, and the prolonged nature of the shutdown has contributed to the potential issues. Our team are on hand to help you return to normal quickly with minimal issues.

Click below to find out more about how we can help and to contact a member of our team. 



Paul Gigg

About the Author

Paul Gigg

Paul has over 35 years in water treatment with what is now Veolia Water Technologies. He was originally a field service engineer, went on to become a regional service manager and for the last 10 years has been a technical support manager.