Water Works pays for Saylorville water too polluted to use, eyes $50M plant expansion

By: - July 6, 2021 12:55 pm
The Des Moines River in downtown Des Moines serves as a water supply and a growing recreational draw.

Des Moines Water Works is eyeing a $50 million expansion that would include wells along the Des Moines River north of downtown. (Photo by Perry Beeman/Iowa Capital Dispatch)

Des Moines Water Works is spending as much as $250,000 a year for Saylorville Lake water that often is too polluted to use, the utility’s CEO said.

That is one reason Water Works is studying a $50 million water-supply expansion, Water Works chief Ted Corrigan added. New wells and plant improvements would help the utility bypass the Des Moines River more often in favor of water from shallow aquifers that is cleaner and requires less treatment.

It is unclear how much the work will increase water rates. In recent years, Water Works’ has bumped up rates between 5% and 10% a year, including a 5% increase in April.

In addition to high levels of algae toxins in the Des Moines River that may originate at Saylorville Lake, drought has left the Raccoon River extremely low. Water Works serves nearly 500,000 customers, mainly with water from the Raccoon and Des Moines rivers.

The utility spends between $100,000 to $250,000 a year for rights to water from Saylorville Lake, Corrigan said. Microcystin, an algae toxin, in the Des Moines River has forced the utility to use mainly the Raccoon River along with a few small backup sources, Corrigan said. Otherwise, the microcystin would increase treatment costs. 

Saylorville, a U.S. Army Corps of Engineers flood-control reservoir, empties into the Des Moines River.

The Des Moines River has had relatively high levels of microcystin, an algae toxin that can cause infections, intestinal problems and even neurological disorders. Recently, ammonia levels have risen in the Des Moines River, too.

The Raccoon River, which has some of the nation’s highest levels of nitrate pollution tied to farming, has not had frequent microcystin issues. 

Water Works’ treated tap water meets federal health guidelines.

The utility continues to negotiate with the Corps on ways to improve water quality, Corrigan said.

Source of algae toxin unclear

Corrigan said it is unclear if Saylorville, or the Birdland area low-head dam, or some other factor is causing the algae toxin outbreaks. Scientists say the toxins are fed by farm runoff and hot, stagnant water conditions.

Rising levels of microcystin led the Corps to recommend swimmers stay out of Saylorville over the Fourth of July weekend.  

Water Works also has one of the world’s largest nitrate-removal systems due to runoff pollution.

A federal judge threw out Water Works’ 2017 federal Clean Water Act lawsuit that attempted to force actions by upstream drainage districts and by extension, farmers, to reduce pollution. Corrigan and other utility officials continue to call for measures to reduce runoff. 

“The only way to improve surface water quality,” Corrigan said in an interview, “is to stop those (pollutants) at the source, or close to the source. Build a bunch of wetlands. Edge of field practices. Cover crops. Those are the tools that are going to work but they have to be done at scale.

“It’s just beyond me that we can allow these land use practices that we know are going to impact off-site waters and individuals and have no expectation whatsoever” of the landowners being required to do something about it, Corrigan said. 

“You literally have tens of thousands of property owners (in the watershed) that you have to convince to do something on a voluntary basis. It just isn’t going to happen,” he added.

Water Works seeks new supplies

Water Works over the decades has steadily added to its water supply options, with plants in Des Moines, near West Des Moines and near Saylorville Lake as well as some underground storage of treated water. 

In the new expansion effort, the first test wells were installed in late June across the Des Moines River from Prospect Park along the east bank.

The idea is for a series of wells in the shallow aquifer, where sandy layers filter many contaminants and the water supply takes less of a direct hit from farm runoff.

Corrigan said the utility most likely will explore seven to 10 sites upstream from downtown Des Moines. Tests of water quantity and quality at the Prospect Park area site are pending. 

It will take five years to get the first of the new wells in operation, Corrigan said. Each site must be tested, obtain a state permit and be approved by the U.S. Army Corps of Engineers.

Water Works hopes the shallow wells will provide 20 million gallons a day to the Fleur Drive main treatment plant. That would cost roughly $30 million of the $50 million total expansion cost.

Current functional capacity of the Water Works system is a bit over 90 million gallons a day.

The utility is seeking a consultant to design an expansion of the treatment plant just south of Saylorville Lake. Cost estimates are still under review. 

Consultants will look at doubling the Saylorville plant capacity to 20 million gallons a day, or more than tripling it, to 35 million gallons a day.

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Perry Beeman
Perry Beeman

Perry Beeman has nearly 40 years of experience in Iowa journalism and has won national awards for environmental and business writing. He has written for The Des Moines Register and the Business Record, where he also served as managing editor. He also is former editorial director of Grinnell College. He co-authored the recently published book, "The $80 Billion Gamble," which details the lottery-rigging case of Eddie Tipton.