Explanation of Cayman Brac Water Quality Incident and Resolution

Following the lifting of the boil water notice in Cayman Brac, the Water Authority would like to explain what caused the issue and the steps taken to rectify it. 

What Happened:

The issue resulted from a failure at the water production plant in Cayman Brac. There was a mechanical issue where a connector within one of the pressure vessels failed. The pressure vessels house the membranes that are used to process feed water.

Additionally, the automatic controls that shut down the system when water quality parameters fall outside the Authority's standards did not operate as designed.

This system failure occurred overnight on Friday, 12 December. It was discovered the following day (Saturday, 13 December) during manual system checks. The operations team took immediate action to rectify the issue upon its discovery. When the scope of the problem became apparent, actions were escalated, and our emergency plan was activated. 

Measures Taken:

One of the initial issues identified was the water's high conductivity, indicating high salinity. Our team began the work to normalise these levels both at the water production plant and across our distribution network.

Members of our Quality Control and Operations Team, who are usually stationed in Grand Cayman, travelled to the Brac on Saturday and on Sunday for the extensive testing required, working alongside the Cayman Brac team.

At the water production plant, the water production train that had a mechanical failure was taken offline, and another train was put into service to begin producing potable water that meets our quality control standards and pumping it into our distribution system.

Simultaneously, a crew began systematically flushing our main pipeline and conducting tests of salinity and other parameters.

By Sunday morning, the salinity levels in the water storage tanks had returned to the Authority's water quality standards.

Test results indicated that the salinity issues did not affect areas east of Coastal Way.

The Authority also conducted tests to ensure its water delivery trucks were not compromised – the results show that all meet our strict safety standards.   

Why a Boil Water Notice was Issued:

Initial tests showed high conductivity, indicating high salt content. Additionally, the mechanical failure at the plant meant the source water did not undergo the required process to produce potable water, in which case bacteriological issues could be a factor. As such, the Authority carried out a regulatory definitive test for bacteriological quality, a measure that assesses public health risk and takes 18 hours to produce results.

While the Authority awaited the results of the comprehensive analyses, screening tests were conducted across the distribution network. These screenings consistently showed no bacteriological contamination, indicating that if the water (while not meeting salinity standards) was consumed, it did not pose a health risk.

To protect public health, a boil water notice was issued just before 3:00 PM on Saturday, 13 December.

"The decision to issue and maintain the boil water notice was made out of an abundance of caution, with public health as our top priority," explains Water Authority Director, Dr Gelia Frederick van Genderen. "While initial screening tests showed no bacteriological contamination, we kept the notice in place until comprehensive analysis confirmed those early results."

The boil water notice was lifted on Sunday evening, following the results of the comprehensive analyses. 

Next Steps:

The Authority is working with our vendors to rectify the programming issue that caused the automatic shutoff safety feature to fail. Additionally, the component that caused the mechanical failure to occur has been replaced. As these measures are implemented, the Authority will increase the frequency of its manual system checks. 

Flushing of the main pipeline has been completed, and salinity levels are back within the Authority's water quality standards. The Authority is working to complete flushing along all side roads to remove residual salinity and ensure our water quality standards are met across the entire distribution network. This work is anticipated to be completed by the end of business tomorrow (Tuesday, 16 December).

"I want to sincerely thank our team who worked around the clock to resolve this issue as quickly and safely as possible. We apologise to our customers for the inconvenience this situation has caused. We are also grateful to the Cayman Brac community for their understanding and patience while we took action to protect our customers and ensure the safety of our water", expresses Dr Frederick-van Genderen.