Water Works plans $15 million for expanded nitrate facility

MacKenzie Elmer
The Des Moines Register

Des Moines Water Works expects to spend $15 million to double the size of its nitrate removal facility to handle growing levels of the compound from the Raccoon and Des Moines rivers.

Utility officials say the new equipment and the cost to operate it will mean bigger rate increases for customers in coming years.

Inside the Des Moines Water Works nitrate removal facility at the fleur drive treatment plant on Thursday, May 4, 2017, in Des Moines. When it was built in the 1990s it was the largest facility of its kind, DMWW is now looking in to expanding the facility again. The facility can process 10 million gallons of water in 24 hours.

The Water Works board this week approved an $800,000 contract with CH2M, an engineering consultant based in West Des Moines, to design the facility expansion.

The utility's growth plan follow its failed lawsuit against three northern Iowa counties. Water Works sued 10 northern Iowa drainage districts claiming they were responsible for high nitrate levels reaching the Raccoon River, which supplies water to 500,000 central Iowans. 

The lawsuit sought damages for the money the utility has spent to remove nitrates from source water. Des Moines Water Works says it spent $633,000 to operate specialized equipment for 65 days in 2016. It spent $1.2 million in 2015. 

District Court Judge Leonard Strand dismissed the lawsuit March 17, saying Iowa's water quality problems are an issue for the Iowa Legislature to resolve. Strand wrote that Des Moines Water Works "may well have suffered an injury" from high nitrate levels, but the drainage districts had no power to address the issue.

With the lawsuit behind it, CEO Bill Stowe said the utility must now look at how it will handle the growing presence of nitrates in the water it pulls from the rivers.   

According to a 2016 report from CH2M, the same consultant hired to design the facility expansion, nitrate concentrations in the Des Moines and Raccoon rivers have been increasing and are expected to continue to rise.

"Now that the lawsuit is gone ... we have to presume the trend will continue upward not downward," Water Works CEO Bill Stowe said. 

Laura Sarcone, Des Moines Water Works communications specialist talks about the infiltration gallery under Water Works Park, the original source of water for the Fleur Drive treatment plant on Thursday, May 4, 2017, in Des Moines.

How does nitrogen removal work?

Des Moines Water Works' nitrate removal facility was constructed in 1991 at a cost of $4.1 million.

Its eight large, turquoise-colored tanks can process 10 million gallons of water per day.

At the time it was built, the Des Moines facility was the largest of its kind in the world. 

"It's kind of like saying you're the biggest chain-smoker in the room. It's not a title we really want to hold," spokeswoman Laura Sarcone said during a recent tour of the Fleur Drive water treatment facility.

Much of Iowa's nitrogen — and nitrates — are in the soil organically.

Nitrates occur when Iowa's rich soils get warm and wet, and microbes convert nitrogen — both that farmers apply and what's available organically — into nitrates, which plants use to grow.

Problems occur, though, when there are no plants in the fields to soak up the nitrates — particularly in the spring and the fall — allowing them to seep into waterways.

Gordon Brand, senior chemist for Des Moines water works talks about the work he does inside the laboratory at the DMWW Fleur Drive treatment plant in Des Moines.

Water Works' nitrate removal equipment is used when nitrate levels are so high that there's not enough water to dilute the compounds to a safe level.

Federal drinking water standards require nitrate levels to be below 10 milligrams per liter. High nitrate levels in drinking water can cause blue baby syndrome, a condition that can be fatal in infants 6 months and younger if not treated.

"If nothing happens in the watershed, we could see (25-30) milligrams per liter at Fleur Drive. So we have to plan for that now, because it could take a while for construction," Sarcone said. 

Des Moines Water Works turned on the equipment for the first time this year on May 21. It has been running ever since.  

Nitrates were at 12 milligrams per liter Tuesday despite high river levels from spring rains, Sarcone said. 

Nitrate concentrations in the Des Moines and Raccoon rivers, according to Des Moines Water Works.

The 2016 CH2M report showed that between 2005 and 2014, nitrate levels in the Raccoon River exceeded federal drinking water standards 22 percent of the time. Levels in the Des Moines River exceeded federal levels 14 percent of the time.  

The Raccoon River reached an all-time high in spring of 2013 when nitrate concentrations were more than twice the federal drinking water standard.

"It really does cost us money to take care of this," Marc Wallace, vice chairman of the utility board.

Regional water utilities?

Questions about the future of Des Moines Water Works and its suburban counterparts linger following a push by the state Legislature to disband the independent water utilities. 

Legislation was introduced this spring that would have scrapped the five-member Des Moines Water Works board, and replace it with a regional board appointed by officials from Des Moines and its suburban neighbors. It was approved by House and Senate committees but never reached a full vote in either chamber. 

Sen. Dan Zumbach, R-Ryan, chairman of the Senate Agriculture Committee, said the legislation could resurface during the 2018 session.

Last month, Water Works trustees Sue Huppert and Graham Gillette told the Register the utility wanted to move forward on regionalization talks. They have since met with officials from the metro's largest suburbs to figure out the next step, Huppert said.

Inside the Des Moines Water Works filter building on Thursday, May 4, 2017, in Des Moines. The water filters through 100 tons of grave and sand in this building before going to the nitrate removal facility.

Meanwhile, suburban water officials are moving forward with plans to meet their own water needs. 

West Des Moines recently announced that two sites along the Raccoon River alluvial aquifer show promise of providing enough water to serve much of West Des Moines and Waukee, some of the fastest growing areas of the metro.

A study found the two suburbs' supply of clean water could come up short in three to eight years. Des Moines Water Works provides all of Waukee's water and some of West Des Moines' supply.

Urbandale has purchased land with the intent of building its own water treatment plant.

If these communities move forward, the need to expand Des Moines' nutrient removal facility could be diminished, Stowe said. 

"Some (expansion) will need to be done," he said. "But we'll pace it differently if some suburbs are taking a hard turn." 

Treating nitrates

Des Moines Water Works on Tuesday approved another $1.1 million to help permanently divert nitrates from the Raccoon River. 

The utility has for years used a chemical ion-exchange process that removes nitrates when levels exceed permit levels. The briny waste that results was reintroduced to the river farther downstream.

Water Works is creating a $2.24 million connection between its nitrate removal facility and a sewer system on the southwest side of Des Moines.

The project, which involves tunneling under the Raccoon River, will allow many of the excess nitrates to be broken down into a gas and released into the atmosphere. Some of the remainder will be combined with bio-solids and applied to farm fields.

Stowe said the utility is looking into newer technologies, outside of the salt-based ionization system, which may produce a less harmful byproduct.

But newer technologies are more expensive, he said, and wouldn't replace the need for the new main to the sewer system. 

Katie Frank, microbiologist for Des Moines Water Works shows an example of a water test that came back positive for chloroform bacteria on Thursday, May 4, 2017, inside the laboratory at the DMWW Fleur Drive treatment plant in Des Moines.

Water Works hires PR firm

The Des Moines Water Works board approved $60,000 to hire the West Des Moines-based Concordia Group to provide public relations services. The group does lobbying, polling, issues advocacy and general political consulting, according to its website. 

In January, the utility hired Concordia on a month to month basis during the legislative session, Stowe said.

Stowe, in April, said the utility would focus resources on affecting environmental protection policy through lobbying. That was after the utility decided not to appeal its lawsuit against 10 northern Iowa drainage districts over high nitrate levels in the Raccoon River. 

"When we feel like we’re under assault from the Iowa Legislature, when folks try to turn our operations over to the city of Des Moines, (Concordia) is going to be very focused on helping to communicate the value of water and fact that it is safe," Stowe said.