Nitrate levels remain high in central Iowa rivers. Here’s a look at how water is tested and treated before the tap – Iowa Public Radio

Report on Nitrate Contamination and Removal Efforts at Des Moines Water Works

Introduction

At the Fleur Drive Treatment Plant in Des Moines, Iowa, water quality monitoring and nitrate removal are critical to ensuring safe drinking water for the metropolitan area and surrounding communities. This report highlights the ongoing challenges and responses related to nitrate contamination in surface water sources, with a focus on Sustainable Development Goals (SDGs) such as Clean Water and Sanitation (SDG 6), Good Health and Well-being (SDG 3), and Responsible Consumption and Production (SDG 12).

Water Quality Monitoring and Nitrate Levels

Lisa Morarend, a chemist at Des Moines Water Works, utilizes ion chromatography to measure nitrate and other contaminants in river water with high precision. The U.S. Environmental Protection Agency (EPA) has set a maximum contaminant level for nitrate in public drinking water at 10 mg/L to prevent health risks such as “blue baby syndrome.”

1. Recent measurements indicated nitrate levels of 14.17 mg/L in the Raccoon River and 13.9 mg/L in the Des Moines River, exceeding the EPA limit.
2. These elevated nitrate levels necessitate effective removal to maintain safe drinking water standards.

Nitrate Removal Facility Operations

Facility Overview

The Fleur Drive Treatment Plant installed a nitrate removal facility in the early 1990s, which was the largest of its kind globally at that time. The facility operates only when nitrate levels require intervention, sometimes remaining inactive for months or years.

Operational Details and Costs

• The nitrate removal system has operated for over 65 days in the current year, with a daily operational cost of approximately $16,000.
• Its capacity is limited to 10 million gallons per day, which is significantly less than the typical demand of 70-80 million gallons per day.
• Treated water is blended with normally treated water to meet federal nitrate standards, a process that is more manageable when river nitrate levels are closer to 11 mg/L rather than 20 mg/L.

Recent Nitrate Spikes and Response Measures

1. On June 8, nitrate in the Raccoon River reached 20.55 mg/L, marking the second highest recorded level.
2. On June 12, nitrate in the Des Moines River was measured at 17.15 mg/L, below the 2013 record of 18.62 mg/L.
3. To alleviate strain on the nitrate removal capacity, Central Iowa Water Works implemented a lawn watering ban starting June 12, which has been effective in maintaining nitrate levels below the EPA threshold.

Challenges of Using Surface Water Sources

Des Moines Water Works primarily relies on surface water from the Des Moines and Raccoon rivers due to insufficient groundwater availability for large-scale use. This reliance presents unique challenges:

• Surface water quality fluctuates rapidly, with nitrate levels changing within hours due to watershed conditions.
• The rivers drain agricultural watersheds characterized by high concentrations of row crops and field tile drainage, contributing to nitrate runoff.
• Nitrate, both naturally occurring and synthetically produced, can accumulate during droughts and subsequently flush into rivers with rainfall.

Monitoring and Partnerships

To enhance preparedness and response, Des Moines Water Works has partnered with the United States Geological Survey (USGS) to install nitrate analyzers in source water rivers. This collaboration enables real-time tracking of nitrate fluctuations from upstream locations to the treatment plant.

Alignment with Sustainable Development Goals (SDGs)

1. SDG 6 – Clean Water and Sanitation: The nitrate removal facility and continuous water quality monitoring contribute directly to ensuring availability and sustainable management of water and sanitation for all.
2. SDG 3 – Good Health and Well-being: Maintaining nitrate levels below EPA limits protects public health, particularly vulnerable populations such as infants.
3. SDG 12 – Responsible Consumption and Production: Operational strategies, including water use restrictions like the lawn watering ban, promote sustainable water consumption and resource management.
4. SDG 17 – Partnerships for the Goals: Collaboration with USGS exemplifies effective partnerships to enhance water quality monitoring and management.

Conclusion

The Des Moines Water Works continues to address the challenges posed by elevated nitrate levels in surface water through advanced treatment technologies, operational adjustments, and community engagement. These efforts support the achievement of multiple Sustainable Development Goals by safeguarding water quality, protecting public health, and promoting sustainable resource use.

1. Sustainable Development Goals (SDGs) Addressed or Connected

1. SDG 6: Clean Water and Sanitation
   • The article focuses on nitrate contamination in river water used for public drinking water, highlighting efforts to ensure safe and clean water supply.
2. SDG 3: Good Health and Well-being
   • Protecting against “blue baby syndrome” caused by high nitrate levels in drinking water relates to health and well-being.
3. SDG 12: Responsible Consumption and Production
   • The article discusses managing nitrate levels, which are influenced by agricultural runoff, implying the need for sustainable agricultural practices.
4. SDG 13: Climate Action
   • Reference to droughts and rainfall patterns affecting nitrate levels connects to climate variability and the need for adaptive water management.

2. Specific Targets Under Those SDGs Identified

1. SDG 6: Clean Water and Sanitation
   • Target 6.1: Achieve universal and equitable access to safe and affordable drinking water for all.
   • Target 6.3: Improve water quality by reducing pollution and minimizing release of hazardous chemicals.
2. SDG 3: Good Health and Well-being
   • Target 3.9: Reduce illnesses and deaths from hazardous chemicals and pollution, including contaminated water.
3. SDG 12: Responsible Consumption and Production
   • Target 12.4: Achieve environmentally sound management of chemicals and wastes to minimize adverse impacts.
4. SDG 13: Climate Action
   • Target 13.1: Strengthen resilience and adaptive capacity to climate-related hazards and natural disasters.

3. Indicators Mentioned or Implied to Measure Progress

1. Nitrate Concentration in Drinking Water
   • The article mentions measuring nitrate levels in river water samples in mg/L, with the EPA legal limit set at 10 mg/L.
   • This is a direct indicator of water quality and safety for human consumption.
2. Frequency and Duration of Nitrate Removal Facility Operation
   • Number of days the nitrate removal facility operates per year (e.g., “more than 65 days” so far this year) indicates the extent of nitrate contamination and treatment effort.
3. Water Usage Restrictions
   • Implementation and effectiveness of lawn watering bans as a measure to reduce water demand and nitrate treatment strain.
4. Monitoring Systems
   • Use of ion chromatography and remote sensors to continuously track nitrate levels in water sources.
   • Partnership with US Geological Survey to monitor upstream nitrate levels in rivers.

4. Table of SDGs, Targets, and Indicators

Source: iowapublicradio.org