At a recent board meeting, Central Iowa Water Works (CIWW) officials highlighted the looming threat of a very strong El Niño and its possible effect on nitrate levels in the region’s drinking‑water sources. Executive Director Tami Madsen explained that climate experts expect this winter to be warmer and wetter than usual, conditions that can increase runoff and keep the ground from freezing solid.
El Niño’s impact on nitrate runoff
“There has been some supposition that we have had high nitrate events from warmer, wetter winters. The ground doesn’t freeze the same way. There’s constant runoff and melting,” Madsen said. In years when heavy rain arrives later in the season, CIWW has recorded spikes in nitrate concentrations in the Des Moines and Raccoon rivers, the primary sources for its water supply.
Monitoring and preparedness
While the utility is not predicting a surge in nitrate levels, it is staying vigilant. CIWW operates a nitrate‑removal facility that has already run for a record 193 days this year, including the first three months of the calendar year. The agency also recently imposed a second straight summer lawn‑watering ban to curb fertilizer use that can contribute to nitrate runoff.
All water delivered to CIWW’s 600,000 customers continues to meet the EPA’s strict standard of 10 milligrams per liter for nitrates, a benchmark that protects public health, especially for infants and pregnant women.
Broader context for Iowa residents
Beyond climate, the agency noted that fertilizer application timing, soil temperature, and land‑use practices all influence nitrate levels. Farmers in the region are encouraged to consider these factors when planning planting and fertilization schedules, a collaborative approach that aligns with the utility’s commitment to safeguarding water quality.
“The best thing for all of us is to be aware and prepared,” Madsen told board members, emphasizing the importance of transparent communication with the public as conditions evolve.
What residents can do
CIWW urges customers to stay informed through its regular updates and to follow any water‑use advisories that may arise. Residents can also support nitrate reduction by limiting fertilizer use on lawns during periods of heavy rain and by maintaining proper drainage on their property.
By keeping a close eye on El Niño’s development and maintaining robust treatment operations, Central Iowa Water Works aims to ensure safe, reliable drinking water for the community throughout the challenging winter ahead.
Original reporting: KCCI Des Moines — read the source article.
