Discussing the events with a Canadian colleague, I learned of an eerily similar event in Canada which took place 16 years earlier, the Walkerton E. coli outbreak. Extreme rain, followed by flooding, provided a pathway for manure runoff to enter a shallow aquifer. The contaminated water was distributed without sufficient treatment or chlorination. Illness, hospitalizations, deaths. So many parallels to Havelock North. While the details differ, it is difficult not to appreciate the likeness of two events, worlds apart. Most notably, the preceding conditions to both events were identical - changing weather, followed by rain. Heavy rain.
Expanded, Principal 4 acknowledges that for a drinking water supply to go from healthy to compromised, something must first change in the environment.
Change can come in many forms. While climatic changes are the most palpable examples of Principal 4 coming to life, to understand its full scope, we cannot look at natural events alone. Principal 4 applies to changes in operations, capital, people, procedures, organisations, politics, legal systems - let alone the powers of entropy, the persistent energy disordering and degenerating the world around us. Now take these changeable features and apply them across our institutions and the boundaries of our drinking water infrastructure - from catchment to point of supply. The task of detecting and managing change is immense.
At a practical level, there are some useful tools that can help us identify change and formulate action. The two most important being Water Safety Plans and Source Water Risk Management Plans. Both of these documents are mandated in the Water Services Act. The development of both plans includes a robust process where hazards and the relative risks are identified. From there, a subsequent management, control, monitor or elimination strategy can be put in place. This exercise prepares suppliers for the full suite of risks to their drinking water supply, ultimately protecting water sources and the public.