More Iowa cities requiring businesses to have backflow prevention

In 1979, nearly 3 million pounds of pork was contaminated at the Swift & Co. packing plant in Marshalltown when employees unknowingly sprayed hog carcasses with wastewater from the kill floor and water used to deodorize rendering equipment.

In 1995, pesticides entered a drinking water distribution system when an accidental water main cut happened while a Louisiana farmer was diluting herbicides in a tank. Some people reported nausea, stomach burns and pains, profuse sweating, diarrhea and shortness of breath.

In 2000, contaminated water lines at an Ohio fairground caused 30 people to get E. coli poisoning.

These incidents reported by University of Florida Training, Research and Education for Environmental Occupations all are examples of what can happen when businesses don’t have backflow prevention systems to keep liquids from siphoning back into the public drinking water supply if there’s a water main break or other drop in pressure.

“A lot of people don't realize that with a main break or pressure loss, there's that back siphoning happening,” said Kyle Wellington, water treatment superintendent for the city of Washington, population 7,255. “It wants to pull from everywhere it can. It's scary to think about, especially in Iowa. I'm sure there are lots of farmers filling up chemicals and they probably don't even think about it.”

Washington is one of a handful of Eastern Iowa communities passing ordinances requiring commercial properties to install backflow prevention systems, which cost between $1,500 and $2,000.

The measures come after the U.S. Environmental Protection Agency earlier this year cited Williamsburg, population 3,364, and Storm Lake, population 11,256, with having “significant deficiencies” in their systems to prevent backflow or cross connection, which is when a fresh water source has a potential link to nonpotable water.

How does backflow happen?

Backflow happens when there is negative pressure in a water pipe, which creates a vacuum and sucks wastewater, chemicals or other liquid into the water supply. The vacuum can be caused by a water main break or if there is high demand, such as when firefighters are drawing water to fight a blaze.

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“In Des Moines alone, we have 300 water main breaks a year,” said John Lins, training specialist with the Iowa Rural Water Association who served 31 years as incident manager for the Des Moines Water Works. “When they make those repairs, they are supposed to maintain positive pressure. Many times they are unable to do that because the pipe is rotten and there’s a huge hole.”

While contaminated water mixed with thousands of gallons of clean drinking water may not sicken people, the risk is too big not to take backflow seriously, Lins said.

“Dilution is not the solution to pollution,” he said. As a drinking water customer “I don't want to drink even a drop of anything that isn't the water I paid for.”

Mid-size cities joining larger communities with ordinances

Most cities of 15,000 or more already require at least some commercial businesses to have backflow prevention. Restaurants, hospitals, pedicure salons, agricultural chemical companies, funeral homes and car washes are among businesses more likely to be required to install backflow valves.

Cedar Rapids, which “probably has the best program in the state,” started in the 1990s requiring backflow prevention devices on the water lines to every commercial property, Lins said.

The Williamsburg City Council Monday night passed an ordinance requiring about 50 businesses in the city to install valves on their water lines, City Manager Aaron Sandersfeld said.

“After we get the ordinance passed, we'll start doing those inspections after the first of the year,” he said. “By May 30, we want the inspections done and information out to customers.”

Most cities implementing new ordinances will require businesses to have backflow systems privately inspected once a year and have those records submitted to an online monitoring company. The city will verify those records and pursue enforcement against businesses not following the ordinance.

Some cities also recommend residential property owners using underground irrigation systems also install backflow preventers.

Comments: (319) 339-3157; erin.jordan@thegazette.com