Pools: Maintenance

Find out about how to safely maintain a school swimming pool.

On this page:

  • Manage water quality
  • Qualify as a water quality tester
  • Drain a swimming pool
  • Manage trees
  • Save energy

Manage water quality

School pools must meet all the requirements of the New Zealand Standard NZS 5826:2010 ‘Pool water quality’.

You can purchase the standard from the NZ Standards website:

The standard aims to maintain safe levels of chemicals and microbiological substances in pool water.

To meet the standard you must:

1 Avoid overuse of the pool

Overusing a pool degrades water quality. Water quality also degrades when chlorine is lost through high ultraviolet levels on a hot day. The Standard sets out the required levels of pool chemicals.

2 Manage faecal contamination

Act quickly if faeces get into the pool or someone with diarrhoea uses it.
Either event can introduce infectious bacteria such as giardia or cryptosporidium into pool water.

3 Test and monitor

Someone with New Zealand Qualifications Authority (NZQA) unit standards in swimming pool water quality must test your pool water 3 times a day (usually before school, at lunchtime and after school). The person may be a caretaker, or someone from your local council.

This test is to check:

  • pH
  • alkalinity
  • calcium hardness
  • chlorine level
  • features that make up the pool chemistry.

The qualified person must have the management of the pool’s water quality under their continuous technical supervision. This person must be readily available when the pool is operating. This doesn’t mean the qualified person must be at the pool at all times – just available if needed. If they are not available, the pool cannot be used.

You must arrange for monthly microbiological monitoring of the pool water. For this testing, pool water samples are sent to laboratories that specialise in water treatment.

Contact your local council to find out about environmental health testing services.

4 Filter the water

The filtration system must be able to cope with the treatment regime in the Standard.

The Standard recommends a 2-hour water turnover rate. If your current filtration system cannot do this, you need to upgrade your filtration system.

To find out about the best method of cleaning your filtration system, check with the manufacturer.

5 Safely handle chemicals

You must have systems in place for safely handling and storing potentially unstable and explosive pool chemicals.

Agencies like the Ministry of Health and Worksafe NZ may test the swimming pool water quality on occasion to confirm that you are fulfilling your obligations.

Qualify as a water quality tester

Unit Standard 20046 is the recommended minimum training to meet NZS 5826:2010 'Pool water quality'. It has been designed for school caretakers.

A number of training providers offer training in the appropriate unit standards.

Most courses are one or 2 days. We suggest that you cluster with other schools to arrange training.

Trees around swimming pools

Trees can be a health and safety hazard around a swimming pool.

Remove trees close to the swimming pool to prevent leaves and branches falling in and contaminating the water, and to prevent people trying to jump from the tree into the pool.

Drain a swimming pool

Pool water contains chemicals that can harm the environment.

To help reduce the need to discharge your pool water:

  • keep the water at a proper chemical balance all year around – this means the water will stay cleaner for longer and won’t need to be emptied as often
  • look for ways to reduce the amount of water that’s discharged by recycling the water.

1 Discharge pool water to a sewerage system

Wherever possible, discharge your pool water to the municipal sewer. The sewerage system will treat the water.

Check with your local council about the amount of water you can discharge.

2 Discharge pool water onto land

If you cannot discharge the water into the sewerage system, the next best option is to discharge it onto land.

To minimise any harmful effects:

  • leave the pool water for one week without adding chemicals before emptying it
  • don’t discharge water onto playing fields if the land is unstable and prone to slips 
  • don’t discharge water where it will flow into storm water systems or waterways
  • make sure it doesn’t flow onto neighbouring properties
  • spread the water onto a large area so it doesn’t pool
  • make sure the pool water is at air temperature before discharging it.

3 Discharge into a waterway or a storm water system

If there is no other option, you may need to discharge your pool water into a waterway or a storm water system.

Minimise any harmful effects by:

  • waiting at least 2 weeks since you last added chemicals
  • adding a de-chlorinator to help remove chlorine
  • having the water tested by a professional to make sure the chlorine concentration is less than 0.5ppm and the copper level is less than 0.2ppm
  • making sure the pool water is at air temperature before discharging it
  • emptying the water slowly so it can be absorbed more easily into the waterway or storm water system
  • ensuring the discharge doesn’t cause erosion or scouring, for example to river banks
  • not emptying the pool when it’s raining as it could cause flooding.

Save energy

Heating a swimming pool can eat up around 50 percent of your energy use.

Pool covers minimise evaporation and reduce the heating energy required by as much as 70%.

To be effective, they need to be maintained in good condition and used consistently – i.e. at the end of each school day, and in weekends and holidays.

Insulating pool buildings can also help to maintain water temperatures

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