ng in Action
Johnson County, Kansas
A paddleboarder enjoying the lake at Shawnee Mission Park.
Photo courtesy of Donna Daugherty
With a population of about 600,000 people, Johnson County is the most
populous county in Kansas. Located just west of Kansas City, Missouri, Johnson
County is home to several growing suburbs and two of the four largest cities
in Kansas (Overland Park and Olathe). Johnson County Wastewater operates
a sewer system that collects and transports wastewater to six wastewater
treatment facilities1 that discharge to tributaries of the Kansas and Blue Rivers.
One of these tributaries, Little Bull Creek, flows into Hilisdale Lake, which is the
centerpiece of a popular local state park.
Challenges
During heavy storms, stormwater and groundwater enter Johnson County's
sanitary sewer system through cracks and improper connections (i.e.,
infiltration and inflow). Under these conditions, the capacity of the sewer
system and treatment facility may be exceeded, resulting in sanitary sewer
overflows (SSOs). In some parts of the county, satellite facilities partially treat a
portion of these SSOs before they are released. However, in other areas, SSOs
discharge sewage directly into the Blue and Kansas Rivers.
In early 2019, Johnson County made plans to tackle complex challenges associated with Clean Water Act
requirements. The county needed to protect water quality in local waterways by addressing eight total maximum
daily loads (TMDLs) as implemented in six separate wastewater treatment facility permits. The county expected
two additional TMDLs to be incorporated into the permits during the next permit term. It also anticipated new
ammonia limits at two of the wastewater treatment facilities, which would require major capital improvements to
comply with such iimits.
In addition to meeting water quality requirements, the county wanted to explore increasing land application
of biosolids and cogeneration of methane at wastewater treatment facilities. This would use resources more
efficiently and reduce operating costs and adverse environmental impacts caused by chemicals in the biosolids.
Integrated Planning in Action
To address water quality challenges and pursue these other environmental priorities, the county created a multi-
phased 25-year schedule to address immediate compliance requirements and then refine the plan as appropriate
based on additional data.
Johnson County began the first phase by identifying ongoing projects and necessary infrastructure improvements
based on previous planning efforts and wastewater system assessments. The county then reviewed existing
JOHNS® N COUNTY
*	KANSAS
Wastewater
EPA Region 7
600,000 population
SSO 11WWTF

1 "Wastewater treatment facilities" (WWTFs) is a generic term for facilities that treat or manage wastewater, including publicly owned
treatment works.

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capital improvement projects and chose possible
solutions to water quality challenges, such as
wastewater treatment facility upgrades and collection
system repair and replacement. The county prioritized
these projects based on their ability to achieve three
main objectives: environmental protection, customer
service, and community enhancement. They also
identified seven sub-objectives (see details in the box
below).
Based on this analysis, the county developed its 25-
year schedule of projects. The schedule included as
many of the highest-priority projects as possible, while
maintaining affordability for rate payers. The county
addressed collection system challenges by including
projects to increase storage and conveyance capacity,
reduce public and private sources of infiltration and
inflow, and rehabilitate the existing infrastructure. The
county sequenced these projects so the ones that met
the most objectives, such as expansion and treatment
upgrades at three wastewater treatment facilities and
the elimination of satellite facilities, would occur within
the first 10 years. Projects that did not address multiple
objectives, such as resource recovery and expansion of
two other wastewater treatment facilities, fell later in the
schedule. Johnson County estimated that the projects
in this first phase of the integrated plan would have
a total capital cost of $2.07 billion over the 25-year
planning period (2020-2044) (see graphic to right).
The second phase of planning will refine the 25-year
schedule using more detailed planning studies and
a more comprehensive assessment of community
priorities. After the second phase ends in late 2022,
Johnson County plans to monitor project performance
and update the integrated plan at least every five years
to achieve the greatest benefits.
The county used existing community engagement
programs and input from the Board of County
Commissioners to solicit feedback on the first phase of
planning. The first-phase Integrated Management Plan
indicates that the second phase will include broader
engagement to support a more comprehensive
assessment of community priorities.
Projected Distribution of 25-Year Integrated Management
Plan Costs by Category
16% WWTF and pump
station renewal ($336M)
4% Planning and
support ($86M)
Total
Program	5% Collection system
Costs	renewal ($108M)
2020-2044
	
9% System capacity and
/	peak excess flow
13% System expansion and /	treatment facility
misc. projects ($268M) /	elimination ($190M)
,
13% System expansion and
misc. projects ($268M)
1 Cost includes $173 million expenditure for Tomahawk Creek WWTF prior to 2020.
Results
In 2019, Johnson County submitted the Integrated
Management Plan to the Kansas Department of Health
and Environment (KDHE), which implemented the plan
through a consent order that same year. The consent
order included implementation schedules for nitrogen
and phosphorus removal at two of the wastewater
treatment facilities, and eventual elimination of satellite
facilities as the county increases collection and full
treatment capacity. KDHE issued amended permits for
these two wastewater treatment facilities in 2020. The
permits acknowledged the receipt of the integrated
plan and indicated that KDHE would use the plan when
making future regulatory decisions. The county expects
to complete the prioritized wastewater treatment facility
expansion project by spring 2022.
Sub-Objectives for Prioritizing Projects in
Johnson County
Improve water quality
Meet regulatory
obligations
Efficiently use and
protect natural resources
Minimize human health
and property impacts
Achieve financial
benefits
Be a good neighbor
Foster responsible
growth and important
development
SEPA
For more information, visit EPA's integrated planning Report to Congress webpage at:
https://www.epa.gov/npdes/inteqrated-planninq-municipal-stormwater-and-wastewater	EPA-832-F-21-013 I June 2021

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