How To Properly Purify Water
by John E Phillips with Erica Miller

Recent Reports Of Bad Water

For the latest statistics available from the CDC for 1995-1996, 13 states reported a total of 22 outbreaks associated with drinking water that made 2,567 persons ill but caused no deaths. Wisconsin had five of these outbreaks, and Idaho had three. The summer and fall had the most outbreaks -- 77%.

The CDC lists outbreaks individually by state and tabulates them by the etiologic agent and type of water system and by the type of deficiency and type of water system.

Etiologic Agents

The CDC categorized 15 (68.2%) of the 22 outbreaks as infectious or suspected infectious etiology and seven (31.8%) as chemical poisonings. The parasite Giardia caused 2 (9.1%) outbreaks with bacteria causing four (18.2%) with the others unknown.

Parasites

Giardia caused problems in Alaska due to untreated surface water and New York, which affected an estimated 1,449 persons, because of both chlorinated and filtered surface water. Researchers found a dose-response relation between consumption of municipal water and illness but found no interruptions in chlorination at the water plant.

Bacteria

Bacteria caused four outbreaks during this time -- two attributed to Shigella sonnei, one to E. coli O157:H7 and one to Plesiomonas shigelloides. The outbreak of shigellosis in Idaho, which affected 83 persons, occurred at a resort supplied by untreated well water, which became contaminated by sewage from a line that drained poorly. The outbreak of shigellosis in Oklahoma, which affected 10 persons, came from tap water supplied by chlorinated well water in a convenience store.

The outbreak of E. coli O157:H7 infection occurred at a summer camp in Minnesota supplied by chlorinated spring water with the contamination attributed to flooding from heavy rains and to an improperly constructed spring. E. coli made the news several times in the summer of 1998 because of infecting water parks and swimming pools.

The outbreak of Plesiomonas shigelloides infection, which occurred in a restaurant in New York supplied by a non-community water system, affected 60 persons -- the largest outbreak of Plesiomonas infection ever reported in the United States.

Viruses

A small round structured virus caused an outbreak at a high school in Wisconsin and affected 148 persons. Although the school received its drinking water from a community water supply, contamination of the potable water system likely occurred from back-siphonage of water through hoses submerged in a flooded football field.

Chemicals

The CDC had seven outbreaks of chemical poisoning reported with: one individual case of chlorine poisoning; and two outbreaks of nitrite poisoning in California and New Jersey that resulted from defective check valves for prevention of backflow that allowed chemicals to contaminate drinking water.

Elevated copper levels in tap water in Wisconsin showed up gastrointestinal illness in at least 37 persons in private homes recently built or remodeled with new copper plumbing. Thirty persons in Florida developed chemical burns in the their mouths after they drank water contaminated with sodium hydroxide when an operator at the treatment plant unintentionally released the chemical into the water. Too, 13 persons at a health-care facility in Iowa developed burning in their mouths and flu-like symptoms after drinking water contaminated with a concentrated liquid soap from a soap dispenser.

Unidentified Etiologic Agents

Eight (36.4%) of the 22 bad drinking water instances had no etiologic agent identified, but the illness associated with at least four of these outbreaks had incubation periods, durations and symptoms complexes consistent with the viral syndromes. The CDC associated three outbreaks with untreated well water, three with inadequate chlorination of unfiltered well water and one with possible short-term cross-connection and back-siphonage problems in the distribution system.

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