Swimming Pools and Spas

Pool Chemicals

In addition to the environmental impact of chemicals used to keep pools sanitary, there are also the personal impacts—some people find the strong odor of some pool chemicals, dry skin that results from swimming, and eye irritation to be sufficient reason to seek out alternatives to chlorine.

One of the issues is whether a pool is private or public. To ensure sanitary conditions with such a vast quantity of bathers, public pools are often “over-chlorinated” as a precaution. In a private pool, where tighter control over swimmers' habits and routine can be maintained, such as the adoption of sanitary practices—for example, ensuring users shower before and after entering the pool—the amount of chemicals required to keep the pool clean can often be reduced.

Traditionally, pools are treated with either chlorine products or bromine. Bromine smells less strong than chlorine and can also be used at higher temperatures, making it a favored option for spas.

Pool maintenance has many environmental impacts, including energy use required to heat, pump, and circulate the water, and the large quantity of chemicals, like chlorine or bromine, needed to keep the pool clean

Source: Demeester/Wikipedia

A “salt” system is often viewed as an alternative to chlorine; however, the device in a salt system is a chlorination device that produces chlorine from the salt. Pools using a salt system that are then back-washed into freshwater streams [Page 426]can cause big problems for the local environment. Some reduced chlorine options are as follows:

• Ozone gas can be used to disinfect water and also break down organic matter. Ozone is used with a greatly reduced quantity of chlorine. The ozone is generated on-site using electricity to power the process, and as such can be energy intensive.
• Ionized copper and silver slowly disinfect water. A device called an ionizer is fitted with metal electrodes that wear away as electrochemical processes are used to deposit the metal ions into the water.

Some zero-chlorine options are as follows:

• Ultraviolet light can be used to help sanitize pool water, with the water passing through a sealed chamber, where it is exposed to a bright ultraviolet light source.
• Copper sulphate, approved for use as a drinking water additive in Europe, often sold under the trade name PristineBlue, is an alternative to pool chemicals, with the benefit that waste pool water can then be used to water plants.
• Persulphates are an option that can be used instead of chlorine. Although they break fats and oils down effectively and kill bacteria, they are less effective at killing algae.
• Polymeric biguanides are a three-stage process, consisting of a treatment that kills bacteria, followed by a second treatment that kills algae, which is finally followed by a hydrogen peroxide treatment that breaks down oils and fats.

Swimming Pool Heat Losses

One of the main ways that energy is “lost” from swimming pools is through heat loss. Appropriate measures can be put in place to ensure that heat loss is minimized, saving energy and reducing the running costs of the pool.

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