Water Systems Maintenance

Continued maintenance of water systems is essential during building’s lower occupancy time

With many office, commercial and retail buildings now running at lower occupancy with decreased activity levels, it is essential to continue maintaining some critical building services such as water systems. This principally prevents unwanted consequences such as bacterial proliferation or premature failures, whilst also reducing the impact if failures do occur.

Additionally, a pragmatic approach for decreased occupancy and activity levels will better facilitate a safe return when the building goes back to normal operation.

Domestic water system

In normal operating conditions, domestic water systems would be used frequently during weekdays and working hours. This includes cold water being drawn, water from cold water storage tanks being drawn and replenished, and hot water produced, stored in calorifiers, drawn and replenished regularly.

Regular usage and replenishment of the domestic water prevents issues like bacteria proliferation and corrosion initiation, which are consequences typically investigated by BSRIA on systems left filled with water and in stagnant conditions for an extended period of time i.e. several weeks or months.

Heating and cooling systems

For closed-loop water systems providing heating or cooling in buildings, most of them already are subject to an intermittent and seasonal operation, and typically benefit from enhanced chemical treatment to maintain the quality of the water and integrity of the system over a longer period of time.

Legal requirements for water systems

Domestic water systems fall under a more stringent legal requirement than closed-loop water systems, as exposure to a degraded domestic water quality for users is high with risk of contamination and infection. For instance, exposure to legionella bacteria must be prevented to all persons under the direct or indirect supervision of a company; this includes employees, contractors attending the company premises, but also visitors and members of the public.

There are numerous regulations and guidance documents applicable to water systems in buildings, which are driven by the nature of the asset:

• Cooling and evaporative towers: ACoP L8, HSG 274 part 1
• Cold water storage tanks, hot water calorifiers, hot and cold water taps, showers: ACoP L8, HSG 274 part 2, BS EN 806-5
• Fountains, vehicle wash, humidifiers: ACoP L8, HSG 274 part 3
• Spa, pools: HSG 282, PWTAG Code of Practice
• Closed-loop heating and cooling systems: BS 8552, BG 50/2013

The above ACoP and HSG documents are freely available from the HSE website (hse.gov.uk/), whilst the other referenced documents are accessible on request from BSRIA Information team by contacting information@bsria.co.uk.

BSRIA recommendations and guidance

In addition, it is prudent to review and evaluate the risk of leaving the building unmanaged (“do nothing” approach), running a reduced maintenance scheme or continuing scheduled maintenance such as planned preventive maintenance.

For critical asset operations in buildings, BSRIA recommends that a business-focussed maintenance is considered to help in the prioritisation of maintenance of critical components and services. This gives a structured risk-based approach to any maintenance regime, with a documented process for any changes. Furthermore, if a reduction in maintenance is decided, the integrity of the critical assets will still be safeguarded, and operation can continue or be restarted without major incident.

The Legionella Control Association has reiterated to their members that maintenance of cooling and evaporative towers, as well as domestic water systems should remain of high importance if they are still filled with water and in partial operation.

BSRIA would like to assist any building owners or tenants, maintenance contractors or service providers who are facing uncertainty in the decision on what to do with the water systems in buildings, which are closed, under a low occupancy regime or simply mothballed.

If you are concerned about what to do with a building under construction and with an incomplete water system, we can offer guidance in line with industry best practice and the soon to be published BG 29/2020 on closed-loop water systems. For buildings running critical assets, BSRIA can survey their condition using various non-destructive methods should safe access be possible.

If failure occurs, BSRIA can provide an independent investigation of the failure to identify resolutions.

For more information please call: +44 (0)1344 465 578 or contact: investigations@bsria.co.uk