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7 steps to ensure safe water in hydrotherapy
Product Support Information
7 steps to ensure safe water in hydrotherapy
Water used in hydrotherapy must be
safe and clean to protect patients who
have compromised immune systems.
This
document
provides
7
key
recommendations to reduce risks of new
infections from contaminated water in
hydrotherapy pools and protect the
hydrotherapy suite from chemical
aggression.
Introduction
Nowadays hydrotherapy is common
practice both as alternative medicine and
as part of hospital’s physiotherapy
treatments. Techniques are continually
improved through worldwide research
investigating new ways to use the benefits
of water to improve health; their outcome
can be found in peer-reviewed journals
such as the Archives of Physical Medicine and Rehabilitation and the International
Journal of Aquatic Research and Education. While Hydrotherapy refers to the
therapeutic use of water due to body's physiological responses submitted at various
temperature and specific equipment (pools, whirlpools, whirlpool spas, hot tubs, and
physiotherapy tanks), aquatic therapy uses the resistance of water in rehabilitating
patients after injury or with chronic illness, and in improving performance. For both
type of therapy, it is essential to ensure safety and quality of the water before any
patient to enter the pool.
Hydrotherapy facilities are accessible within senior living centres or physical therapy
facilities from the NHS hospitals or charities. Physiotherapists also recommend
hydrotherapy and aquatic therapy for improving recovery times following surgery and
injury and for giving athletes a strenuous workout with a reduced risk of injury; facilities
have been designed and dedicated to athletes from the world's foremost athletic
organizations. All hydrotherapy facilities will require dedicated water safety
management and the 7 key following recommendations remind the different
parameters to monitor and procedures to follow.
Product Support Information
Ref: ASI10003v1
Date: 27th June 2014
Product Support Information
Following the 7 following steps will help to reduce health risks to users
including spread of infection or simply discomfort but also limit damage to
equipment and save operation costs.
1. Monitoring temperature
• The temperature in the hydrotherapy suite should be recorded twice daily and
should remain at 35.5 to 36°C.
• Patients with certain medical conditions such as neuropathy will suffer from
changes in temperature, therefore temperature control is vital.
• Higher temperatures can affect patients with heart disease and lung disease.
• Colder temperatures may worsen symptoms in patients with Raynaud's disease,
chilblains, acrocyanosis, or erythrocyanosis.
2. Monitoring pH
pH should be measured at the beginning of the day, then every 2 hours and finally
at the end of each day. It should fall within the range 7.2 - 7.8.
3. Ensure the chemicals used for disinfection such as chlorine are at the
right levels
• Optimize the disinfection treatment to avoid skin irritation (dermatitis) or
bacterial skin infections, particularly when patients have open wounds. Dermatitis
may be caused by contact with contaminants or additives in water such as
dichloramines and trichloramines formed by oxidation of organic compounds (skin,
sweat, urea..) by chlorine.
• The free chlorine should be measured three times a day and should fall
between 1.5 and 5.0 mg/L. The total chlorine should be measured once with the
free chlorine to give the combined chlorine (total chlorine-free chlorine). Free
chlorine should not exceed 1/3 of the total chlorine.
• Cyanuric acid and total dissolved solids (TDS) should be measured daily.
The values should not exceed 200mg/L and 1500mg/L respectively.
Product Support Information
Ref: ASI10003v1
Date: 27th June 2014
Product Support Information
4. Monitor the microbiological contamination
Microbiological contamination of the pool can result in pathogenic micro-organisms
causing infections to bathers. These contaminants can be introduced into the pool by
bathers, from the pool filters and occasionally from defects in the pool engineering (e.g.
that allow the water to be contaminated by sewage). Hydrotherapy pools require
increased frequencies of testing as the people using these pools are immersed for
longer periods and may be more vulnerable to infection.
o UK guidelines - The Pool Water Treatment Advisory Group (PWTAG)
Currently, no European legislation provides recommendations for minimum standards
for the quality of water used for specific functions in hospitals. In the UK, however,
there are a number of documents that provide guidance about the microbial quality of
water to be used for hydrotherapy pools, as well as general guidelines relating to
Legionellaand P. aeruginosa in hospital water. These documents also indicate the
microbiological tests necessary to ensure that the quality of the waters used falls within
safe.
To maintain water quality, The Pool Water Treatment Advisory Group (PWTAG)
recommends regular microbiological testing of swimming pool water according to
guidelines laid down in a BSI Code of Practice PA39:2003 ‘Management of Public
Swimming Pools. Water Treatment Systems, Water Treatment Plant and Heating and
Ventilation Systems’.
Hydrotherapy pools should be tested twice weekly as the people using these pools are
immersed for longer periods (as are staff) and may be more vulnerable to infection, to
monitor
the
presence
of
the
following
indicator
micro-organisms:
Test
Limit
Total Viable Count (24 hr 37°C)
Total Coliforms
E Coli
Pseudomonas aeruginosa
Legionella (Spa Baths only - quarterly)
Maximum 10 cfu / ml
Maximum 10 cfu / 100 ml*
Zero
Maximum 10 per 100 ml*
Zero
Product Support Information
Ref: ASI10003v1
Date: 27th June 2014
Product Support Information
Additionally tests should be performed:
• Before a pool is used for the first time or put back into use after being shutdown
for repairs.
• If there are difficulties with the treatment system.
• If contamination has been noted.
• As part of any investigation into possible adverse effects on bathers’ health.
• To validate changes to pool treatment.
Microbiological analysis should be carried out in appropriately accredited laboratories,
e.g. UKAS laboratories. The pH level and the concentration of free and total
disinfectant in the pool water should be measured when the microbiological sample is
collected. Microbiological samples should be taken beginning at a depth of 200 mm to
400 mm below the surface of the pool.
The results of routine microbiological testing should always be interpreted in
conjunction with:
• Chemical tests performed on site and/or in the laboratory at the time of sample
collection.
• Review of the maintenance records for the pool, including records of the pH,
residual disinfectant levels, mechanical failures and water appearance and
other untoward events.
Samples should be tested for aerobic colony count, coliforms, Escherichia coli and
Pseudomonas aeruginosa:

Aerobic colony count
The aerobic colony count (ACC), sometimes called the total viable count, colony count,
or plate count, is a general test that indicates whether the pool disinfectant regime is
effective in controlling contamination under operational circumstances. The ACC can
become increased where there is a higher bather load, reduced chlorine residual or
where there are defects in water treatment. The aerobic colony count should normally
be 10 or less colony forming units (cfu) per millilitre of pool water. If a colony count
above 10 cfu/ml is the only unsatisfactory microbiological result, and residual chlorine
and pH values are within recommended ranges, the water should be retested.
Product Support Information
Ref: ASI10003v1
Date: 27th June 2014
Product Support Information

Total coliforms
Coliforms within swimming pools can be considered as an indication of faecal
contamination or poor hygiene (e.g. contamination from shoes or leaves in outdoor
pools). Their presence indicates that the treatment has failed to remove this
contamination. Coliforms are sensitive to disinfectant and should be absent in 100 ml
of pool water. A repeat sample should be taken whenever coliforms have been
detected. A coliform count of up to 10 cfu/100 ml is acceptable provided that:
• Coliforms are not found in the repeat sample;
• The aerobic colony count is less than 10 cfu/ml;
• There are no E. coli present;
• The residual disinfectant and pH values are within recommended ranges.

Escherichia coli
Escherichia coli is normally present in the faeces of most humans, mammals and birds.
The presence of E. coli in swimming pool water is an indication that faecal material has
entered the pool water from contaminated skin, or from faecal material that has been
accidentally or deliberately introduced. It also indicates that the treatment has failed to
remove this contamination. E. coli should be absent in a 100 ml sample. However,
because most bathers will have some faecal contamination of their skin, particularly if
they have not showered before bathing, a single positive sample may be the result of
recent superficial contamination by a bather that has not yet been decontaminated by
the disinfectant residual. A repeat sample should then be taken.

Pseudomonas aeruginosa
Pseudomonas aeruginosa can grow within untreated waters and in biofilms. It can
cause skin, ear and eye infections when present in large numbers and outbreaks of
skin infections have been linked to swimming pools and spa pools.
Well operated pools should not normally contain P. aeruginosa. If the count is over 10
P. aeruginosa per 100 ml, repeat testing should be undertaken. Where repeated
samples contain P. aeruginosa the filtration and disinfection processes should be
examined to determine whether there are areas within the pool circulation where the
organism is able to multiply. Where counts exceed 50, pool closure should be
considered.
Product Support Information
Ref: ASI10003v1
Date: 27th June 2014
Product Support Information
Where there is evidence of gross contamination the pool should be closed to prevent
illness in pool users. The local Consultant for Communicable Disease Control (CCDC via health authority) should be contacted.
The following should be considered as gross contamination:
• Greater than 10 E. coli per 100ml in combination with:
- unsatisfactory aerobic colony count (>10 per ml)
- unsatisfactory P. aeruginosa count (>10 per 100ml)
• Greater than 50 P. aeruginosa per 100ml in combination with high aerobic
colony count (>100 per ml)
o Australia – NSW
The Standards Australia Hydrotherapy Pools AS3979-1993 is available from
Standards Australia in each State.
Contact your Local Council/Health Department for local guidelines.
Minimum sampling frequency for microbiological analysis - NSW Australia
Heterotrophic plate
count (HPC)< 100
CFU/mL
E.coli< 1
CFU/100 mL
Pseudomonas
aeruginosa
< 1CFU/100 mL
Monthly
Monthly
Monthly
Hydrotherapy
pools
5. Maintain the poolside area
• The poolside area should be cleaned daily with pool water and weekly using a
solution containing 200 ppm of free chlorine using appropriate dilution of chlorinereleasing tablets.
• In the event of soiling, the area should be cleaned immediately according to the
spillage policy.
• A yearly inspection and maintenance should take place and coincide with pool
emptying.
Product Support Information
Ref: ASI10003v1
Date: 27th June 2014
Product Support Information
6. Ensure effectiveness of maintenance procedures

In addition to the daily use of insitu test kits, pool operators are advised to
provide monthly analytical results, from an independent third party laboratory,
which detail the microbiological quality of the water in their pools and spas

The following points should also be recorded and monitored:







Appearance of the water at the beginning of each day with respect to
colour and turbidity
Number of patients treated in the pool at each session should be
recorded (each hour of use should be divided into three 15-minute
treatment sessions with a 5-minute break), and patients should not stay
in the pool for more than one hour session
Incidents of pool soiling and remedial action taken
Health complaints by staff or patients
The kits used for measuring pH, chlorine, and water balance should be
kept in a good state of repair, only the recommended cuvettes should be
used and the testing performed in one designated area that has constant
incident light
Daily maintenance and regular engineering inspections
Back flushing should occur at a frequency to maintain water quality
Product Support Information
Ref: ASI10003v1
Date: 27th June 2014
Product Support Information
7. Have a contingency plan with remedial actions
Problem
Possible reasons
Potential remedy
pH too high
Mains water alkaline
and hard
Alkaline disinfectant
used
Mains water is acidic
Acidic disinfectant used
Add more acid
pH too low
pH erratic
pH difficult to change
Cloudy, dirty water
Cloudy, clean water
Colour water; or slimy,
coloured growth on
pool walls, floor….
Water has bad taste
and smell, irritation of
eyes
Water is not sufficiently
buffered
Water is too well
buffered
Bathing load too high
Filtration inadequate
Hardness salts
precipitating out of
solution
Entrained air or
coagulant
Algae build up due to
sunlight, poor
hydraulics, loss of
disinfection
High combined chlorine
pH incorrect
Consider changing to acidic
disinfectant
Add more alkali
Consider changing to
alkaline disinfectant
Check and adjust total
alkalinity
Alkalinity potentially too
high, test and decrease
Reduce bathing load
Check filter, flow rate and
backwash
Check water balance index
value
Check coagulant dosing
Check air release on filters
Vacuum of algae, increased
residual level, backwash or
use algaecide
Shockdose, Superchlorinate
Maintain free chlorine
residual
Replace part of water
Check it and correct if
necessary
Water balance is derived from the measurements of pH, Alkalinity, Calcium hardness,
Temperature and TDS (Total Dissolved Solids) and can help in the hydrotherapy water
management by informing about risks of corrosion or scaling.
Learn more about Palintest Water Balance Index, and about Langelier Water Balance
Index.
Product Support Information
Ref: ASI10003v1
Date: 27th June 2014
Product Support Information
Further readings
Guidelines on managing hydrotherapy suites
o While there are no specific health and safety regulations governing
swimming pools, hydrotherapy pools and spas, p 15 to 41 of HSE document
HSG179 (Managing Health and Safety in Swimming Pools) summarise the
health and safety legislation with which all pool operators must comply.
o Extract from BSI Code of Practice PAS39:2003
Pool Water Treatment Advisory Group
http://www.pwtag.org/INFO%20codeofpractice.php
o Guidelines for Environmental Infection Control in HealthCare
Facilities
(pages 67-69) from CDC and the Healthcare Infection Control
Practices Advisory Committee (HICPAC).
More information on hospital-based recommendations for medical uses of
water is found at CDC’s Infection Control Guidelines (Division of Healthcare
Quality Promotion).
http://www.infectioncontrolservices.co.uk/hydrotherapy_intro.htm
Benefits from Hydrotherapy
o http://www.spaevidence.com/spaevidence/hydrotherapy/research?learnmore=1
o http://www.arthritisresearchuk.org/arthritisinformation/therapies/hydrotherapy/accessing-hydrotherapy.aspx
o http://www.csp.org.uk/professional-networks/atacp
o http://www.hydroworx.com/research-education/research-studies/
Product Support Information
Ref: ASI10003v1
Date: 27th June 2014