Site logo

Des Moines Metropolitan Wastewater Reclamation Authority Wastewater Treatment Plant


The Des Moines Metropolitan Wastewater Reclamation Authority (WRA) Wastewater Treatment Plant is a cornerstone of environmental stewardship and public health in Iowa’s capital city. Originally formed in the early 1970s, the Des Moines WRA has continually evolved, leveraging cutting-edge technologies and community engagement to sustain its mission. Serving a growing population and addressing new environmental challenges define its proactive approach to wastewater management.

Population and Service Area

Located in the heart of Iowa, the Des Moines WRA serves a metropolitan area encompassing around 500,000 residents. This includes not only Des Moines itself but also the surrounding suburbs and municipalities. The authority’s service domain covers nearly 850 square miles, making it one of the largest such facilities in the region.

Wastewater Volume and Treatment Capacity

The Des Moines WRA efficiently manages a significant volume of wastewater, receiving an average of 60 million gallons per day (MGD). This figure can surge to over 100 MGD during wet weather events due to inflow and infiltration. The plant boasts a treatment capacity of approximately 120 MGD, ensuring adequate headroom to handle peak loads while maintaining compliance with stringent environmental regulations.

Comprehensive Treatment Process

Preliminary Treatment

Upon entering the treatment plant, wastewater undergoes screening to remove large debris such as sticks, rags, and plastics. This process protects downstream equipment from damage and operational inefficiencies.

Primary Treatment

The screened wastewater is then conveyed to primary clarifiers, where sedimentation processes allow heavier solids to settle at the bottom, forming primary sludge. Lighter materials, including grease and oils, float to the surface for removal.

Secondary Treatment

Secondary treatment employs biological processes to further purify the wastewater. Using aeration tanks and secondary clarifiers, organic matter is metabolized by microorganisms, which substantially reduce the biochemical oxygen demand (BOD) and eliminate most suspended solids.

Tertiary Treatment

For advanced cleaning, tertiary treatment involves additional filtration and disinfection processes. Chlorination and dechlorination stages ensure pathogens are effectively eradicated before the treated effluent is safely discharged into local water bodies.

Sludge Management

The primary and secondary sludge collected during the treatment processes undergoes anaerobic digestion, where bacteria break down organic materials, producing biogas—a valuable source of renewable energy. The stabilized biosolids are further processed and repurposed as fertilizer or soil conditioner, aligning with sustainable waste management practices.

Recent Local News and Developments

Nitrogen and Phosphorus Removal Initiative

In light of increasing regulatory demands, the Des Moines WRA recently embarked on an ambitious project aimed at reducing nitrogen and phosphorus discharges, pivotal in combating waterway eutrophication. The $100 million endeavor involves upgrading existing systems to include biological nutrient removal (BNR) technologies and enhancing chemical processing units.

Flood Mitigation Efforts

Recent years have seen heightened concerns over climate change and its impact on urban infrastructure. To address potential flood risks, the WRA has initiated several mitigation projects, including constructing additional stormwater retention basins and upgrading pipeline capacities. These initiatives are designed to bolster the resilience of the wastewater system against extreme weather events.

COVID-19 Surveillance

Amid the global pandemic, the Des Moines WRA joined the forefront of public health surveillance by testing wastewater for COVID-19 remnants. These efforts have provided invaluable data, allowing health officials to detect and respond to outbreaks more efficiently, showcasing the indispensable role of wastewater treatment in contemporary public health strategies.

Key Projects and Future Plans

Renewable Energy Generation

Harnessing the byproducts of wastewater treatment, the WRA has placed a strong emphasis on renewable energy generation. The biogas produced during sludge digestion is captured and converted into electricity and heat, significantly offsetting the plant’s energy consumption. Future expansions intend to integrate solar panels and advanced battery storage systems, further amplifying the sustainability quotient.

Infrastructure Renewal and Expansion

With an eye towards future growth, the WRA is continually investing in infrastructure improvements. This includes the construction of new interceptor sewers to accommodate urban expansion, rehabilitating aging pipelines, and upgrading mechanical and electrical systems to enhance operational efficiency. A proactive asset management strategy ensures that the facility can effectively cater to the increasing wastewater volumes projected over the next few decades.

Public Outreach and Community Education

The Des Moines WRA recognizes the importance of public awareness and community involvement in promoting environmental stewardship. The authority regularly conducts educational programs, plant tours, and workshops, aiming to demystify wastewater treatment processes and underscore the critical role that wastewater management plays in safeguarding public health and the environment.

Interactive exhibits and informational campaigns are tailored for schools, civic organizations, and the general public, fostering a culture of environmental responsibility and encouraging community members to adopt water-wise practices.

Community Engagement

Environmental Advocacy

As part of its community engagement efforts, the Des Moines WRA actively participates in local environmental advocacy groups. Collaborations with non-profits and educational institutions are focused on joint initiatives aimed at protecting regional waterways and improving water quality.

Citizen Reporting Systems

To bolster community involvement, the authority has launched a citizen reporting system, allowing residents to promptly report issues such as illegal discharges or blockages in the sewer system. This participatory approach ensures quicker responses to potential problems, enhancing the overall efficacy of the wastewater management framework.

Green Infrastructure Grants

In a bid to promote sustainable urban planning, the Des Moines WRA provides grants for green infrastructure projects within its service area. These grants support community-led initiatives like rain gardens, permeable pavements, and green roofs, which aid in stormwater management and reduce the load on the sewer system.

Open Houses and Annual Reports

Transparency and communication are key to maintaining public trust. The WRA periodically holds open houses, offering citizens the opportunity to witness operations firsthand and engage with staff. Annual reports detailing operational performance, financial standings, and strategic goals are publicly accessible, ensuring accountability and openness in the authority’s dealings.


The Des Moines Metropolitan Wastewater Reclamation Authority Wastewater Treatment Plant stands as a testament to modern engineering and community-focused public service. Through ongoing investments in technology, infrastructure, and public education, the WRA not only meets but exceeds regulatory standards, setting a benchmark for wastewater management in the region.

In facing the challenges of urban growth, climate change, and public health, the Des Moines WRA exemplifies the innovation, adaptability, and collaborative spirit needed to navigate the complexities of contemporary wastewater treatment. As it moves toward a sustainable and resilient future, the WRA remains committed to protecting the environment, enhancing public health, and fostering community engagement—affirming its role as a vital steward of Iowa’s natural resources.