Overflow Control Plan 

Supplemental Overflow Control Plan

Regulatory certainty through 2035 In March of 2021, Environmental Services successfully worked with Missouri Department of Natural Resources (MDNR) to change its 2012 Amended Consent Judgement to continue addressing overflows and improving water quality while focusing investment on the most cost-effective solutions for Springfield. Springfield City Council approved proposed changes on April 5, 2021 and the Second Amended Consent Judgment was filed with the Greene County Circuit Court on April 27, 2021. The filing establishes a new plan and timeline for investment in improving Springfield’s aging sewer system.

The new plan, called the Supplemental Overflow Control Plan (SOCP), provides regulatory certainty for our City as we continue to implement state and federally mandated upgrades, rehabilitation, and enhancement of the City’s wastewater collection and treatment system to minimize capacity-related sewer overflows and treatment plant bypasses and their negative impact on water quality. The SOCP uses Integrated Planning to establish the remaining level of investment at $300 million and extend the compliance schedule with a re-evaluation date of 2035. The new $300 million investment commitment replaces the final $125 million of investment required by the previous Overflow Control Plan (OCP) and adds 10 years to the compliance schedule which will lower the annual financial impact on sewer ratepayers. 

Several successful projects in Springfield’s current OCP will continue under the SOCP including:

The Private Sewer Repair Program

• Municipal Separate Storm Sewer System (MS4) compliance 

• Sewer collection system renewal projects to rehabilitate aging infrastructure 

• Sewer collection system optimization, including automation and monitoring to improve system performance 

• Targeted projects to reduce sewer overflows in critical places such as parks and neighborhoods 

• Wastewater treatment plant renewal projects

Additional categories proposed in the supplemental plan include investments in “green infrastructure” projects that have been found to be a cost effective way to improve water quality while beautifying our community, as well as construction of a new operations facility to accommodate increased staffing and equipment required under the plan. 

Based on the current financial projections for the City’s Sewer Enterprise Fund, the extended compliance timeline allows the investments outlined in the proposed SOCP to be supported by the revenue generated by the currently ratified sewer rate structure, which should allow future sewer rate increases to be much less than previously contemplated under the OCP.  

Springfield is not alone in investing large sums of money toward its aging sewer system. Cities across Missouri, and the nation, are dealing with state and federal mandates to eliminate sewer overflows and improve water quality.

Background on the OCP

A long-term solution

Beginning in 1995, the City of Springfield entered into a series of cooperative consent judgments with MDNR in compliance with the federal 1972 Clean Water Act to invest in the improvement of infrastructure, maintenance, and capacity of Springfield’s sanitary sewer collection and treatment facilities. The 1995 consent required the City to study sources of infiltration and inflow, to complete specific rehabilitation projects in the collection system and to upgrade a peak flow clarifier at the Southwest Wastewater Treatment Plant. The City met or exceeded the requirements of the 1995 consent judgment by 2008. 

The City and MDNR negotiated an amended consent judgment in 2012, which consisted of a $50M Early Action Plan to be executed while details of a longer-term Overflow Control Plan (OCP) were developed. The commitments of the Early Action Plan were completed in 2018 and a long-term OCP was approved by MDNR and City Council in May of 2015.

The 2015 OCP committed to investing $200 million over 10 years. The program consisted of two phases:  1) the  Foundation Projects Phase (2015-2020) which included $75 million dedicated toward pipe renewal, capacity upgrades, system monitoring, and treatment plant renewal programs as well as staff and equipment resources; and 2) the Advanced Action Plan phase (2021-2025) which dedicated $125 million dedicated to a similar list of projects.  

Since the approval of the OCP, the City has completed the Foundation Projects Phase and has been gathering data, analyzing results of completed projects and planning for future improvement projects. 

The 2015 OCP included a requirement for reevaluation and submittal of an updated plan by 2025.  Through Integrated Planning, however, the City determined an earlier reevaluation would ensure the City’s sewer investments would be on projects/activities that make sense for the sewer system and community. This led to the City proposing the Supplemental Overflow Control Plan which revised the Advanced Action Plan phase and extended the timeframe to 2035. The additional timeline allows the city to remain in compliance with federal law while establishing predictable sewer rates for the next 15 years. 

View the original Overflow Control Plan (OCP) here.


Collect, carry & clean

Springfield operates under separate sanitary sewer and stormwater collection systems, each designed to carry either wastewater or stormwater.

Springfield’s sanitary sewer system is a vital piece of community infrastructure. Often taken for granted, public sanitation is considered the single greatest advancement that society has made towards improving public health. Besides, an efficient sewer system supports economic growth and is one of the key pieces of public infrastructure that allows the dense development that defines us as a City.

The City of Springfield’s sanitary sewer system contains more than 1,200 miles of pipe and over 28,000 manholes. All the wastewater collected throughout the City is transported, to one of two, award-winning wastewater treatment plants. There the water is treated and released into both Wilsons Creek, which travels to Table Rock Lake, and the Sac River, which goes into Stockton Lake.

Over the next decade, most of the City’s sanitary sewer system will have exceeded its expected life span of 50 years. Significant portions of the system are over 100 years old. Because the sewer system is so vital to our community, it is important to continually invest in renewing and maintaining this infrastructure.


Money to maintain & income to improve

Springfield's Sanitary Sewer System is supported by the Sewer Enterprise fund which is primarily supported by sewer use fees (i.e., wastewater rates). In addition, there are other minor revenue streams within the enterprise fund, such as a hauled waste tipping fee for trucks that take liquid waste to the treatment plants as well as permit and connection fees related to new developments.

Revenue collected from wastewater ratepayers is only used to fund programs within the wastewater enterprise system, so revenue collected represents the true cost of operating the sewer utility over the long term.

Based on the current financial projections for the City’s Sewer Enterprise Fund, the extended compliance timeline allows the investments outlined in the proposed Supplemental Overflow Control Plan to be supported by the revenue generated by the currently ratified sewer rate structure, which should allow future sewer rate increases to be much less than previously contemplated under the original OCP.  Sewer use fees were last set by City Council in January 2020, for periods beginning July 1 of years 2020 through 2022.

Regulatory Drivers

Reducing Pollution

The Federal Clean Water Act of 1972 (CWA) established the basic structure for regulating pollutant discharges into waters of the United States. The CWA gave EPA the authority to implement pollution control programs to reduce pollution from permitted sources. One such permitted source is wastewater treatment plants and sewer collection systems like those in place in Springfield. Under this law, these systems are only allowed to discharge into streams at a specific location and the discharge must meet certain chemical and biological standards.

However, when it rains, stormwater can enter the sewer system through cracks and defects present in the infrastructure. Improper connections on private property, such as connected roof downspouts or sump pumps, can also contribute to flows to the system. These sources of stormwater are collectively called ‘inflow and infiltration’ or I&I. The sewer system was not designed to carry significant amounts of stormwater. When too much water enters the sanitary sewers, it can causes the collection and treatment systems to exceed their capacity, resulting in overflow from manholes into our neighborhoods and causing treatment plant bypasses into our local waterways.

Not only does this harm the environment, public health and the general quality of life in our community, but it has also become a legal issue. Sanitary sewer overflows are not allowed under the Federal Clean Water Act. The EPA’s enforcement of the Clean Water Act has increased significantly over the last few decades. As a result, most large communities around the country are being brought into compliance through a legal mechanism called a consent judgment.

The City has been under a consent judgment with the State of Missouri since 1995 to reduce Sanitary Sewer Overflows (SSOs) and treatment plant bypasses.