The cost of bacteria-caused drinking water failures

Disease-causing bacteria must be avoided in drinking water supplies, and as a result, investigating bacteria-based failures is essential. The water industry is expected to provide quality assurance and improvement on its current methods wherever possible. However, failures still happen and are found during routine water quality monitoring. These failures have a financial implication for the water companies, however there has been little investigation into what the cost of these failures are and how this impacts the company. 

STREAM researcher Kate Ellis sought to fill this knowledge gap with her research on the cost of bacterial failures. The study focused on failures due to coliform and e. coli being found during routine checks, across five different British water companies. In total, there were 737 failures of this type during the study period. The cost was calculated from the staff hours needed to deal with the failures, the collections of additional samples, transportation, and any additional activities necessary for the place where the sample was being collected. The cost of different types of failures were calculated as well; specifically customer tap failures, service reservoir failures, and water treatment works finished water failures. 

The average costs of the investigations were between £575 (for a customer tap failure) and £4,775 (for a water treatment works finished water failure). These numbers can provide these and other water companies the ability to budget in operational costs for dealing with these failures. Furthermore, the costs can be used to justify the need for increased funding for preventative strategies. Companies may have been reluctant to spend the money on research and implementation of new strategies before, however now the cost can be compared to the cost of the investigation of the failures as well as repairing the issue, and the total cost over time. The comparison of the cost of the two options is likely to make the funding for prevention appear more reasonable, allowing for fewer bacteria related failures in the future. 

Full article: Understanding the costs of investigating coliform and E. coli detections during routine drinking water quality monitoring, Kate Ellis et al., Urban Water Journal