A typical March day in Collingwood, Ontario. The snow filled winter had been a boon to the region. Spring skiing's corn snow and sunshine were on the minds of many residents and visitors to the Town. For others, the long awaited summer cottage season was just around the corner. Anticipation was in the air. Until sporadic reports of people suffering from intestinal disorders began to come into the offices of the local Simcoe County District Health Unit. Local media informed residents that there might be temporary problems with drinking water.

Sampling and testing were done for the widely known Giardia lamblia and its more obscure counterpart, Cryptosporidium. Since its discovery in 1895, Cryptosporidium has become a major concern in drinking water systems because of its resistance to chlorine and other common disinfectants and to many of the drugs used to treat cryptosporidiosis. The ingestion of just one Cryptosporidium oocyst can cause diarrhea, stomach cramps, nausea, dehydration and headaches.

For those with healthy immune systems, the cryptosporidic symptoms simply run their course although the symptoms may reoccur. However, for individuals with suppressed or weakened immune systems such as the elderly, hospitalized or sufferers of AIDS, cryptosporidiosis can be fatal.

Emergency response water purification unit treats water at the hospital.

Even though neither Cryptosporidium nor Giardia were evident in the Collingwood water supply, "Boil Water" warnings were issued by the Collingwood PUC as a safeguard. Reports of "stomach and intestinal disorders" continued to come in from different sources although any link between these and drinking water supply problems were tenuous, at best.

Radio, television and newspaper quickly picked up on the story. Time and space were devoted to the examination of topics such as cryptosporidiosis and water purity concerns in society at large. Public awareness was aroused nationwide. Collingwood's residents and visitors were concerned that the Town's water supply might indeed be compromised. The Collingwood PUC moved quickly to provide residents with a sure, recognized safeguard against the invasion of the dreaded cysts. Working long hours together with their consulting engineer, Ainley and Associates, they researched a solution to the problem.

It was determined that the solution necessitated both a short- and long-term response. In the short term, the Collingwood PUC wanted to provide a safeguard for those for whom the oocysts might pose the highest risk, namely, those persons with weakened immune systems. Clearly the hospitals and nursing homes were the priority.

In the long term, the Collingwood PUC wanted to provide safeguards against any possibility of oocyst invasion occurring again. An absolute barrier to oocyst invasion was needed as a safeguard. Membrane filtration provides the only absolute barrier to the Cryptosporidium and Giardia cysts in drinking water. Responding to the public concerns articulated by the Collingwood PUC and the technical requirements posed by Ainley and Associates, Zenon Environmental Inc. was commissioned to make the solution a reality.

Zenon had the immediate response capability needed to provide a safeguard for those who might be at highest risk. Within 60 hours, a Zenon mobile Reverse Osmosis unit and a technical support team were on their way to the Collingwood hospital site. With the assistance of the Collingwood PUC and the General and Marine Hospital, ultrapure water was on its way to the facility within days of the alert.

Meanwhile, Collingwood Operations Staff, together with Ainley and Associates, Zenon and their agent, Pro Aqua, worked out a long-term response. The absolute barrier approach was to be applied to any possible, ongoing threat of cyst invasion. Zenon was commissioned to provide the safeguard technology in as short a time frame as possible. Within the space of hours, resources were mobilized to design and deliver the water purification units and provide the operations know-how needed for the coming peak wateruse time of this holiday town.