Since 2012, an annual three-day festival has taken place in northern England. Water is supplied for domestic purposes from a borehole. The borehole supplies a lake, which acts as a reservoir and the water is then piped to points around the festival grounds. As the lake level lowers, a pump is automatically started to draw water from the borehole. In the festival’s first year the local authority advised that the source should be abandoned as sample results from standpipes around the site indicated microbiological contamination, and during the festival the supply was periodically inadequate. Water was supplied to the temporary event via bowsers.
In preparation for the 2013 festival the local authority undertook a risk assessment. In addition the local authority advised the organisation responsible for the water supply to consult and follow the British Standard for the supply of water to temporary events – BS 8551.
Previous monitoring had confirmed microbiological contamination and high levels of nitrates. In response the organisers had installed a nitrate removal system and UV treatment for the duration of the festival. The local authority agreed the distribution network installation plan which was based on BS 8551, which included the removal and storage of the standpipes and treatment system after the event following an appropriate methodology and at a suitable location to prevent contamination.
In 2013, the festival operated using the borehole and lake supply with monitoring being undertaken by the local authority and the organisers. The results were all satisfactory except for nitrates.
In 2014, the festival organisers relaid the distribution network, and flushed and cleaned the system a week prior to the event.
A sample taken prior to the festival opening contained E.coli and coliforms. In response, the company rechlorinated and flushed the supply. The limitations of sampling and analysis meant that there wasn’t time to confirm the effectiveness of the second chlorination of the distribution system. Instead, the local authority and the organisers agreed that an alternative source of water should be used as a precautionary measure and installed a bowser to supply the festival.
An investigation revealed that the sample failures were a result of the water stagnating in the newly established temporary distribution network. The water supply company had no procedure to achieve any turnover in the distribution network once it had been flushed and charged. To remediate this, flushing points have been installed to create turnover of water to ensure a residual chlorine level can be maintained.
The local authority have required new procedures to be written to ensure the flushing regime is adhered to and a suitable chlorine residual is maintained to reduce the risk of sample failures from low turnover in future events. BS 8551 is currently being reviewed and the need for adequate maintenance of temporary supplies prior to an event starting will be reinforced.