DES MOINES, Iowa —
Nitrate levels in the Des Moines and Raccoon rivers are still above the Environmental Protection Agency's safe limit of 10 milligrams per liter, but local water officials say treatment facilities continue to produce safe drinking water.
On Friday, Central Iowa Water Works leaders held a media update and gave a tour of the Saylorville Water Treatment Plant.
During the update, CIWW executive director Tami Madsen addressed the concerns and rumors about the water not being safe to drink.
"We don't anticipate that there's going to be any concern with our water not meeting safe drinking water standards because of the hard work that everyone is doing with the lawn watering ban," Madsen said. "If there were to be any concern, Central Iowa Water Works would reach out and share any notification that is required."
The status of drinking water was one of the main points shared Friday, during the tour of the Saylorville Water Treatment Plant. The plant is one of several facilities CIWW mentioned would be expanded or built over the next seven years.
The Saylorville plant will undergo an expansion. Right now, it works to pump 10 million gallons of water per day. Once it expands, it will produce 20 million gallons per day.
According to Central Iowa Water Works, the plant receives water from shallow wells along the Des Moines River. Once it gets back to the plant, the water goes through two large filters — or so-called membranes — to prepare the water for customers.
"The first membrane is an ultrafiltration membrane, and that membrane will remove any sort of particles or anything that would be in the water," said Ted Corrigan, the CEO of Des Moines Water Works, which is a systems operator with Central Iowa Water Works. "The second set of membranes are reverse osmosis membranes, and those membranes literally just reject anything except water."
CIWW leaders say the goal is to continue meeting safe drinking water standards.
"If it's safe to water your plants with a water can or by hand with a watering hose," Madsen said. "But for now, we need to continue to implement the lawn watering ban."
Rumors have also been addressed on Facebook, as can be seen by Des Moines Water Works' replies to concerned people on the utility's Facebook page.
Utility staffers responded to a question on their page Friday morning from a woman saying she heard from "4 different people who work there that the water isn't safe anymore."
DMWW's response: "This is not true. Nothing has changed about the quality of the water being produced. Water meets all standards for drinking and all other uses. Feel free to DM us the names of the DMWW employees and we can research. Thank you!"
They also addressed a question about reports of unsafe nitrate levels from home tests.
DMWW said to that: "Finished drinking water nitrate level from the Fleur Drive Treatment Plant meets The EPA Safe Drinking Water Standard. Nitrate concentrations are measured at each step of the treatment process and analyzed through our sophisticated state-certified laboratory. The accuracy of DIY tests can be affected by age, storage and testing method. Many test kits are measured in nitrate (NO3) but the Safe Drinking Water Standard is measured in nitrate-nitrogen (NO3-N). NO3 refers to the entire nitrate ion, while NO3-N specifically refers to the nitrogen component within the ion. Home testing kits have limitations and are never as accurate as tests performed in a professional laboratory."
The latest nitrate readings from Friday show 15.37 mg/L in the Raccoon River and 14.1 mg/L in the Des Moines River, with treated water at 8.11 mg/L from the Fleur Drive Treatment Plant and 7.93 mg/L from the McMullen Treatment Plant. Officials say the lawn watering ban remains in place.
The Environmental Protection Agency has a standard for nitrate of 10 mg per liter. Nitrate levels above the EPA standard could be harmful to pregnant women and children under 6 months old.
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