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Storage and Distribution of Hot and Cold
Water
Requirements:
The Owners and Operators of
Water Distribution Systems have the legal responsibility to ensure that the risk
of Legionella contamination to Users of the systems is controlled.
Such systems would be found in Hotels, Hospitals,
Schools, Leisure Centers, Public Conveniences, Residential Homes….
Inadequate maintenance of Hot and cold water systems
as well as poorly designed or installed systems can lead to health risks.
Current Legislation and Guidance
Documentation
- Health and Safety Commission (HSC) Approved Code of Practice and Guidance
L8 (2000).
- The Health and Safety at Work etc Act 1974
- The Management of Health and Safety at Work Regulations 1999
- COSHH Regulations 1999
Operation
The Health and Safety Commission (HSC) Approved Code
of Practice and Guidance L8 (2000) stresses that whilst the tasks required to be
undertaken to control the risk, from Legionellosis, may be contracted out to
external specialist service providers, the responsibility to ensure the
competence of such services, remains entirely with the systems owners and
operators.
Records
Records are the critical activity to enable the
system Owner or Operator to demonstrate that suitable and adequate assessment
and monitoring procedures are in place.
Records are divided into two distinct areas:
Risk assessment Records: These records should
contain details referring to Risk Assessments undertaken on the existing and new
systems and will contain details of both the use and non use of the system.
Records should be retained for the period to which they apply, and for a minimum
of two further years.
Monitoring Point Records:
Records of measurements from
the identified and declared Temperature Monitoring points. Monitoring records
must be retained for at least five years.
These Risk Assessment and Monitoring Point records
are in addition to any Personnel Training records and notes, any cleaning and
disinfection procedures with associated certificates, and results of any
chemical analysis.
Summary of Responsibility
It is the responsibility of the operator to ensure that the operation of any
system does not present a risk to the health and safety of users of the system,
including employees, visitors to site or to the general public.
Risk Assessment
The operation of the system should be assessed on a
two yearly frequency or when there is reason to suspect that the operation of
the system is no longer valid.
For example:
- A change of water supply
- Temperature Monitoring results
- Persistent legionella positives
- A case of legionnaires disease is associated with the system.
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Temperature Monitoring for Hot and Cold
Water systems
For all hot water clarifier systems, the water
Inlet temperature and the outlet temperature should be continuously
monitored.
Hot water should be stored at 60°C and distributed
in such a manner that it reaches the tap outlets at 50°C within 1 minute of the
tap being turned on.
If water is not drawn from the system on a regular
basis, for example: daily, the temperature of the stored water, must be raised
to greater than 60°C for a minimum of 1 hour before being used.
To meet the recommendations of the current
Legislation and Guidance, water storage systems will normally require an
independent temperature monitoring system.
A typical site could require up to 1000 temperature
monitoring points: such as taps, storage vessels, mains inlets. The actual
implementation will be scalable governed by the number, the size and physical
distribution of the points within the site
Having to supply water to tap outlets at 50°C can
introduce a risk of scolding, this will be of particular concern where children
and the elderly could be at risk.
For example:
Children’s
nurseries or residential homes. The installation of mixer taps can be employed
to enable the temperature to be lower, and safer, at the point of delivery. In
these situations it is essential that the temperature monitoring points are
correctly positioned.
The Eurotherm Data Acquisition system, offers two
approaches for use in these applications, each providing a series of unique
features:
Network Approach
- The networking capability of the instruments allow data to be periodically
sent to a local server or remote PC, for viewing and subsequent processing.
- SMS and email notification and alarming allows the system to promote
advanced servicing and support.
Non Network Approach
- On sites where networking is not possible access can be gained to the
instruments via a remote radio link or manually, with the aid of a Portable PC
or Personal Digital Assistant (PDA) device.
Generic Features
- Individual probes continuously monitor storage tank inlet and outlet
temperatures as well as the cold water feed.
- Each input is logged, alarmed and stored within the product, typically for
up to 3 months, although this period will be dependent upon the system
capability.
- Alarm Indication via Remote Monitoring package.
- In locations that experience a heavy demand on water supply, metering of
usage can be included and calculations used to enable excess usage to be
alarmed indicating possible leakage or water miss-use.
- Eurotherm's Legionella reporting software is a purpose designed package
allowing the user to create the necessary reports, based upon standard
(included) or customized formats
- To compliment the hardware systems Eurotherm offer on site support and
calibration services further reducing the cost of
ownership.
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