Archive for Sunday, October 16, 1994


October 16, 1994



Cryptosporidium parvum is a tough, tiny, infectious protozoan with a hard shell that protects it from chlorine treatments in drinking water.

It lives in animal intestines. Infected feces are believed to contaminate lakes and rivers that, in turn, supply much of the nation's drinking water.

When ingested by humans, Cryptosporidium can cause diarrhea and flu-like symptoms. It can kill people with impaired immune systems due to AIDS, cancer and other health conditions.

Scientific uncertainty has slowed the testing of Kansas drinking water for a potentially deadly microbe.

Seventeen months after a microorganism in the Milwaukee public water supply killed 100 people and made more than 403,000 sick, three of the largest water departments in Kansas, including Lawrence, are just now making arrangements to test their drinking water for the single-celled Cryptosporidium parasite.

Utility and health officials think current treatment techniques used in Kansas are adequate to prevent outbreaks.

While the American Water Works Assn. believes that most of the nation's 300 largest cities have tested their water for Cryptosporidium, water utility and health officials say the slow response in Kansas reflects widespread doubts about the value of costly and possibly unreliable testing techniques.

It is, they say, a case of both science and government regulation trying to catch up with a highly publicized but poorly understood public health issue.

Unreliable data?

"The labs I contacted a year ago didn't have qualified personnel," said Shari Stamer, laboratory services supervisor and pretreatment coordinator for the Lawrence Department of Utilities, which draws and treats water from the Kansas River and Clinton Lake.

The department is now negotiating with laboratories in Vermont, Pennsylvania and California for Cryptosporidium testing services.

"We need certifiable data, especially if we're going to inform the public," Stamer said.

"We've also heard so many stories that the testing can give false positives," said Bruce Northup, laboratory director of the Topeka Water Utility, which on Thursday sent a sample of its water to a New Jersey company to be tested for Cryptosporidium. The tests take several weeks to complete.

"If you go to a lab and someone is not really highly trained, they could identify crypto when it isn't there," Northup said. "There's only a handful of people in the country who know what they're doing. You've got to really know, because there are so many different types of things that could look like Cryptosporidium."

Even more difficult is determining whether Cryptosporidia found in a water sample are alive, Northup said.

"The big problem now is, if we do find it we have to decide whether we want to alarm the public or not," he said.

Water utilities are required by law to notify the public if hazards are detected in public water supplies.

How much is too much?

But there is disagreement among health officials and no standard specified by law about how much Cryptosporidium in tap water constitutes a health hazard.

Meanwhile, water utilities throughout the nation are waiting for the U.S. Environmental Protection Agency to issue standardized testing rules, expected in 1995 at the earliest.

On Monday, Water District No. 1 of Johnson County, which draws drinking water from the Kansas and Missouri rivers for about 300,000 residents in 15 cities, including Lenexa, Overland Park and Leawood, will begin tests for the microbe.

"We almost question whether we're sampling prematurely," said Tom Schrempp, the district's assistant director of operations. "The sampling procedures are still experimental.

"At the same time, we're concerned about it. We want to make sure that our water is safe and protected. At this point we feel like we've got enough to go on to proceed with doing the test."

Wyandotte County has not tested its water, but an official there noted that the Kansas City, Mo., water supply, drawn just downstream from the Wyandotte collection area on the Missouri River, has been tested.

The Wichita Water and Sewer Department has no immediate plans to test for Cryptosporidium.

"The goal in waiting is to wait until the test has established acceptance throughout the water treatment industry," said Terryl Pajor, laboratory director of the Wichita Water and Sewer Department.

Process of elimination

Pajor, and other health and utility officials, said that a properly run water system should adequately filter out the parasite.

"The fact that it is in the surface water is one thing," said Joan Dent, the American Water Works Assn.'s director of public affairs. "But if the system is filtered well and all of the other steps in the treatment process are running smoothly, then most likely it is being inactivated by the treatment process."

"If the system is working properly then it is inherently designed to eliminate the Cryptosporidium," said Greg Crawford, a spokesman for the Kansas Department of Health and Environment.

"What went wrong in Milwaukee is their system failed miserably to provide the kind of quality water treatment that the Kansas systems are required to provide."

An optimal process

In Lawrence, as in Topeka, Johnson and Wyandotte counties and in Wichita, multiple treatments and filtration designed to screen a vast majority of the particles in raw water should prevent an outbreak of cryptosporidiosis, the generally non-fatal disease caused by Cryptosporidium, Stamer said.

"We always keep optimizing our water treatment processes," Stamer said. "I haven't lost sleep over it because I know we do a pretty good job."

"The organism is nothing new," Topeka's Northup said. "I suspect that it's been in drinking water for as long as we've been making drinking water.

"If people weren't getting sick before, their chance of getting sick is probably less today. We're doing a better job of producing a higher-quality drinking water than we were 10 years ago."

Still, the AWWA recommends caution, both for water utilities that the association says should be testing their water for Cryptosporidium, and for those who drink the water.

"It is a much more complex problem than we have faced before," the AWWA's Dent said. "It's not black and white.

"Because of Milwaukee, and in the past seven years several identified outbreaks, plus the fact that there are parts of the population that we are now recognizing are more vulnerable, we're beginning to realize that maybe those sensitive populations need to take extra precautions," Dent said.

That would mean, for people with AIDS, cancer and compromised immune systems, boiling their tap water before drinking it, just to be safe.

Commenting has been disabled for this item.