Poolsafe Facilities

Health and Safety Incident – High Chloramines

Kristin Raynes, Assistant Manager, H20 Xtream

What happened?

A primary school group (130 children approximately) came for a fun swim on the way home from their camp, they joined a smaller group from a college of around 30 people and a mix of older customers in the facility. Staff opened the three hydro slides for the groups at 1.15pm, within a few minutes, children from the primary school group started experiencing eye irritation, respiratory discomfort and coughing at the base of the slides. Approximately 15 children were affected. One child was unable to stand, and two others required oxygen and Ventolin before being able to move out of the area. In total 11 children were taken to Hutt Hospital for observation.

How it happened?

The probable cause of the incident appears to be a build-up of chloramines in the slides. Chloramines can cause some pool users to have eye irritations and respiratory issues. However, there was not one specific factor that caused this build-up of chloramines but rather a combination of factors, high PH as recorded on the day, bather excretions, poor ventilation in the slide tower and the aeriation of water being supplied to the slides (all detailed below)

• The leisure pool had a large school group using this body of water and this would naturally introduce a high amount of organic matter into the leisure pool and river ride areas.

• The pools water tests that day showed a reading for PH of over 8.2ppm. High

PH levels will decrease the effectiveness of Free Available Chlorine (FAC) for disinfection of the pool and will lower the FAC in the water which in turn can cause more chloramines. High PH will also cause eye irritation and respiratory issues.

• Chloramines are also caused by aeration of the pool. The slides draw water from the rapid river which is then aerated again inside the slides, creating an environment where chloramines can rise up and be trapped inside the slides.

This is especially the case with the black slide due to it being 66 metreslong.

The majority of it is also outside and painted black so it becomes far hotter internally on sunny days.