Steve Zibell, Reedsburg's city engineer, watched in dismay and disbelief last Monday night as the rapidly rising waters from the Baraboo River swirled over a sandbag barrier and started climbing the walls of the community's sewage treatment plant.
Like soldiers surrounded by an encroaching enemy, Zibell and his workers had no choice but to shut down the plant's pumps and electronics and retreat. The plant has been inoperable since and the 1.3 million gallons a day of sewage that the plant normally processes is being pumped untreated into the Baraboo River.
Of all the impacts of the floods that have slammed the Upper Midwest the past two weeks, one of the most unpleasant and potentially unhealthy has to be the millions of gallons of raw sewage that flooded treatment plants have been forced to divert into local waters.
The state Department of Natural Resources reported late last week that at least 161 communities across southern Wisconsin have sent untreated sewage into nearby streams and lakes because of floodwaters that have overwhelmed pumps and pipes, or threatened to short-circuit electrical power in the plants.
That's more raw sewage flowing into Wisconsin rivers at one time than anybody with the DNR can remember in recent history.
Flooding in 2004 led 130 communities to release untreated sewage, according to Todd Ambs, director of the DNR's water division. But Ambs said those were scattered widely across the state and most were not as serious either in frequency or volume as this year's spills.
"What a mess," said Ken Johnson, water leader for the DNR's South Central Region. While receding waters have allowed many of the plants to operate normally once again, some damaged treatment systems, such as Reedsburg's, continue to dump sewage. Among the others still reporting discharges by week's end were those along the flooded reaches of the Rock River.
The discharges have raised important questions about whether sewage treatment systems are being built and maintained well enough to withstand the increasing frequency and ferocity of storms, and whether the public is adequately notified of the releases.
The most immediate health threat, according to public health experts, comes from direct contact with sewage that is pumped into waterways, especially lakes and streams that are popular for swimming, boating and fishing. The raw sewage contains pathogens that can cause stomach illnesses and diarrhea, according to Tommye Schneider, director of environmental health for the Madison-Dane County Health Department.
Kirsti Sorsa, environmental technical supervisor for the department, added that anyone with an open wound or sore who comes in contact with sewage-laden water can develop tetanus.
Most susceptible to such illnesses are children, mostly because of their tendency to explore, said Schneider.
"They love to stomp around in water," Schneider said, "And it's not just water in most cases right now."
Mary Young, who is leading the Division of Public Health's flood response, said the tainted floodwaters are one of the leading concerns of local health departments with which the state agency is working.
"It's a serious situation," Youngsaid. "I don't think there is any floodwater that we can assume is safe." Young said the agency has issued numerous press releases to local health departments advising them to alert residents to the danger of contact with contaminated waters.
Sorsa said another health threat posed by the wastes - along with the fertilizer and other nutrients the floods swept into the water - is the growth of dangerous blue-green algae. In Madison, she said, where city beaches were closed last week because of discharges from the Madison Metropolitan Sewerage District, three beaches were closed again Thursday because of blue-green algae.
VIRUSES IN WELLS
Mark Borchardt, a researcher at the Marshfield Clinic who studies viruses in drinking water systems, said he is concerned about the long-term threats to drinking water supplies. The DNR's Ambs said testing has shown that no public drinking water supplies have been affected. Most drinking water wells pull water from deep in the ground, far below the affected surface waters.
But Borchardt, who in previous studies has found viruses even in Madison's deep drinking water wells, said communities with wells along polluted waterways, such as the Baraboo River, are probably likely to end up with some viruses in their wells due to the sewage. Most communities do not regularly test their water supplies for viruses.
"Any community that has public wells along these rivers, like the Baraboo, is pumping this stuff," Borchardt said.
Ambs said the situation is somewhat ameliorated by the heavy volume of floodwaters, which can dilute the sewage quickly. And he added that there have been no reports of fish kills, another good sign that the waste is not remaining at levels high enough to cause serious health problems. Ambs also said this biological pollution will break down quickly compared to chemical pollutants that can linger in sediments for years.
Schneider and other public health officials said the pathogens thrive at body temperature and generally die within a week or so when released into the environment.
But many treatment plants continue to discharge sewage even as floodwaters recede. Reedsburg may be unable to treat sewage for as long as a month, according to Zibell, the city engineer.
While local governments are required to report sewage releases to the DNR within 24 hours, Ambs said the operating permits issued the plants do not require public notification of such discharges.
"It's obviously encouraged," said Ambs. "But I think that's something that is going to be looked at." Ambs said many communities keep the public informed about the release of raw sewage. In Reedsburg, Zibell said the sewage is being pumped into a city park and then into the Baraboo River. He said the park has been closed and the public notified.
In Madison, Jon Schellpfeffer, manager of the Madison Metropolitan Sewerage District, said the district worked closely with the city and county public health department to notify people of the discharge, a rare event for the plant. The district was forced to divert a total of about 1.5 million gallons of sewage into a number of local waters, including Cherokee Marsh, Starkweather Creek and Lake Mendota.
HIGHER PLANT STANDARDS
Longer-term questions raised by the many discharges have to do with construction and maintenance of sewage treatment systems. Two straight years of flooding and the possibility of more weather extremes due to global climate change have engineers wondering if sewage treatment plants will need to be built to higher standards.
Tom Gilbert, a wastewater facility planning coordinator with the DNR, said no plant can be designed to completely withstand the kind of onslaught that many have faced in the last two weeks. But he added that design standards may have to be reconsidered. Plants, for example, are required to be surrounded by berms that protect against water that rises 2 feet above the level predicted for a 100-year flood. Maybe, Gilbert said, that will have to be higher.
Schellpfeffer said such considerations are being discussed in Madison as the sewerage district works on a 50-year master plan. He said there is thought being given to increasing the maximum flow rates that new pipes can handle. That means bigger pipes, he added.
AGING SEWER SYSTEMS
Recent flooding has also spotlighted a problem that plagues all public utility infrastructure in the United States - a lack of investment in maintenance and replacement of aging equipment. A report last year from the National Association of Clean Water Agencies estimated that it will take expenditures of $300 to $500 billion over 20 years just to catch up on repair and replacement of crumbling sewage treatment and drinking water systems.
Preliminary reports from the DNR show that several of the overflows in the last two weeks happened because of malfunctioning equipment. In some cases, the floodwaters simply overwhelmed pipes and pumps. But in other cases, pipes may have been previously cracked or damaged and left unrepaired, thus allowing water to infiltrate and swamp treatment systems. In both Baraboo and Reedsburg, for example, city engineers report at least 50 sinkholes - an indication that a pipe beneath the ground has failed.
"In a lot of cases, it's out of sight, out of mind," said Schellpfeffer. "The sanitary sewer systems aren't really visible. So some of these things tend to not get taken care of until you have an event like this." Some communities may pay a price. Ambs, the DNR's water chief, said that while all sewage releases are illegal, the agency will take into account which systems had worse problems because of equipment that was in ill repair. Some of those, he added, may be more likely to be referred for legal action. After overflows during 2004 floods, several communities were fined. Milwaukee, for example, paid a $500,000 settlement, about half of which was for fines and legal costs.
In Reedsburg, engineer Zibell doesn't need the DNR to tell him what needs to happen before the next flood. He knows exactly what he will do once the flood crisis is over.
"We're going to get that berm up as high as we can," said Zibell. "We don't want to go through this again."\ \WHAT, EXACTLY, IS A 100-YEAR FLOOD?
A big flood can happen any year. The term "100-year flood" is a statistical designation meaning that there is a 1-in-100 chance that a flood of such size will happen during any year.
Scientists use statistics and observe how frequently different sizes of floods happened, as well as the average number of years between them, to determine the probability that a flood of any given size will be equaled or exceeded during any year.\ \WATER SAFETY TIPS
Do not swim or bathe in rivers, streams, creeks, or lakes in flooded areas.
Don't let children play in or near flooded water, or in areas that have been recently flooded.
Wash your child's hands frequently, especially before meals.
Disinfect toys that may be contaminated, using a solution of eight ounces of bleach in one gallon of water.
Discard any toys that may be contaminated with sewage; young children may put these items in their mouths.
Sewage may back flow from your septic or municipal system through floor drains and toilets. Any affected areas, such asbasements, must be cleaned an disinfected with a chlorine solution. Wear gloves. Anything that cannot be cleaned should be thrown out.
Private wells that are flooded or have floodwaters near them should not be used until they are tested for bacteria and disinfected