NELSON WASTEWATER TREATMENT FACILITY IMPROVEMENTS PROJECT
Frequently Asked Questions
PROJECT OVERVIEW
What is the background of Nelson Wastewater Treatment Facility?
The Nelson Wastewater Treatment Facility (WWTF), also referred to as the Nelson Complex, was constructed in phases, beginning in 1947, to address the needs of the growing community.
​
The Nelson WWTF is located in the northeastern corner of the city of Mission with the city of Roeland Park to the east and Wyandotte County to the north. The Nelson WWTF serves two main tributary basins in northeast Johnson County – containing all or part of the cities of Fairway, Merriam, Mission, Overland Park, Prairie Village, Roeland Park and Shawnee. (view map of service area)
​
The Environmental Protection Agency (EPA) and the Kansas Department of Health and Environment (KDHE) require discharge limits for constituents such as ammonia, nitrogen and phosphorus. These constituents can be harmful to aquatic life and encourage the growth of nuisance algae in surface waters. The treatment technology currently in place at the Nelson WWTF is not capable of meeting these stricter future water quality standards. The collection system that the Nelson WWTF serves is also aging and can experience issues during large rainfall events.
​
In 2018, Johnson County Wastewater (JCW) commissioned a consulting engineering team to determine the optimum solution to these issues and develop a long-term capital improvement plan for the Nelson service area. The plan recommended a new Nelson WWTF to address the issues of the aging facility and regulatory obligations. The plan is also flexible to allow for the collection system issues to be mitigated over a 25-year period.
​
What are the drivers for the project?
The Nelson Wastewater Treatment Facility (WWTF) is Johnson County Wastewater's (JCW) oldest treatment facility, dating back to the 1940s. A significant portion of the facility is at or near the end of its useful service life. The treatment technology currently in place is not capable of meeting future water quality standards. JCW looked at ways to control costs long-term and minimize future rate increases while meeting environmental standards and maintaining Johnson County’s quality of life. Replacement of the facility with newer technologies and provisions for adding expanded future wet weather treatment was determined to be the most cost-effective way to meet future regulations and provide a long-term treatment solution for our customers.
​
The four main drivers for the project are:
-
Repair or replacement of aging infrastructure. The majority of assets are beyond their expected useful life and need to be replaced.
-
New water quality regulations necessitate upgrades to the existing Nelson WWTF to improve water quality in Turkey Creek and downstream waters and meet permit requirements.
-
Minimize nuisance issues (odors, noise, etc.).
-
Set the facility up for future wet-weather flow as collection system improvements are made over a 25-year period.
What are the goals of this project?
-
Provide the most cost-effective, long-term solutions for ratepayers
-
Improve water quality using the latest, proven technologies
-
Preserve the high quality of life enjoyed by Johnson County residents
How will the project improve our quality of life?
-
Protecting the environment and improving water quality in Turkey Creek and for downstream communities;
-
Improving treatment operations by applying the latest, proven technologies; and
-
Providing the most cost-effective, long-term solutions for ratepayers.
FINANCIAL COSTS/SAVINGS
Why are wastewater rates increasing?
Industry-wide, the cost of wastewater service is increasing due to inflation on operating and construction costs, increasing regulations and reinvestment in aging infrastructure. The Nelson Wastewater Treatment Facility (WWTF) is Johnson County Wastewater's (JCW) oldest treatment facility. A significant portion of the facility is at or near the end of its useful service life. Like other wastewater utilities, JCW must invest in its infrastructure to keep it in good working order to maintain our level of service.
​
In addition, state and federal regulations pertaining to water quality have become more stringent over time, requiring investment in advanced treatment technologies. The treatment technology currently in place at Nelson WWTF is not capable of meeting future water quality standards.
What will this do to JCW rates over time?
Johnson County Wastewater (JCW) and the Board of County Commissioners are highly focused on keeping rate increases reasonable and competitive with other local wastewater utilities. We have developed an Integrated Plan that has been accepted by regulators. The plan affords JCW the flexibility to prioritize improvements to maximize value for each dollar spent, and to schedule the improvements over time so as to not place undue burden on our ratepayers.
Residential customers’ rates are the same throughout the county, regardless of which facility serves them. Over the next several years, JCW sanitary sewer rates are projected to increase about 5% annually for sanitary sewer service throughout the JCW service area. JCW rates include operations as well as capital improvements across the JCW service area, and the capital improvements encompass more than just the Nelson WWTF Improvements project. JCW updates sewer rate projections each year and continues to strive to implement actual rate increases below our projections. JCW residential customers pay for wastewater based upon their average winter water usage (AWWU). The average residential customer (assuming a 4,000 gallon per month water use) pays $43.10 per month in 2021 for wastewater service. JCW rates continue to remain among the lowest in the metropolitan area as well as below the national average.
How was the decision for a new facility determined?
As with all of Johnson County Wastewater's (JCW) infrastructure investments, the choice of improvements for the Nelson WWTF is based on:
-
Determining what technologies are available that can achieve the required objectives
-
Evaluating capital and annual operating costs of alternatives, so as to select the ones that are most cost-effective.
An alternatives analysis of potential treatment technologies is currently underway to optimize the value of improvements at Nelson WWTF to ratepayers.
What are ways you are looking for efficiencies to benefit ratepayers?
There are a number of cost-saving measures that will be incorporated into the Nelson WWTF design. These include reuse of methane produced during biosolids digestion for heating purposes, high-strength ammonia sidestream treatment, which is a method that allows for reduction in the size and cost of the main treatment process, discontinuation of landfilling biosolids through beneficial land application, and high-efficiency motors and lighting. These improvements save money and provide sustainability benefits as well.
How much money is needed to build the new facility?
A recently completed planning study projected the total project cost for the treatment facility and associated pump station improvements would be more than $400 million. JCW is pursuing a low-interest loan through the Water Infrastructure Finance and Innovation Act for a portion of the project.
Is a new treatment facility capable of treating 15 million gallons per day (MGD) enough to handle future development?
Yes. The Nelson service area is fully developed. There will likely be some re-development over time,
but this will have minimal impact and has been considered in the sizing of the planned facility.
CONSTRUCTION
How long will the facility be under construction?
The project will be constructed in phases, with various key milestones to allow portions of the existing treatment facility to remain in service. Construction is anticipated to start in early 2024 and be completed in 2029.
What impacts should residents expect to see during construction?
Efforts will be undertaken to help minimize the impacts to surrounding residents/businesses. During construction, residents can expect to see increased truck traffic associated with construction and hauling of items to and from the worksite. A preliminary traffic study has identified that this will be most prevalent at the Lamar-Foxridge-I-35 interchange. We will work with the local cities – Mission and the Unified Government of Wyandotte County and Kansas City – as well as the Kansas Department of Transportation (KDOT) to determine what modifications are required to minimize these impacts. In addition, mitigating measures will be put in place to help control items such as noise and dust. The public will be informed in advance of anticipated construction impacts.
Will you demolish the existing facility?
The majority of the existing treatment facility will be demolished and replaced with new, state-of-the-art and energy-efficient facilities. The project will be constructed in phases, with various key milestones to allow portions of the existing treatment facility to remain in service.
How much bigger is the proposed footprint?
The footprint of the new treatment facilities will be located within the existing site confines. There will be some offsite work to replace pipes from offsite pump stations to the facility. There will be community outreach to discuss these projects with affected nearby stakeholders as those plans develop.
TECHNOLOGY/ODORS
What about odor control?
The existing technology is from the 1940s, and odor control wasn’t part of the original facility design. Over the years, we have retrofitted odor control into the facility. New technologies will be installed to provide a more complete odor control system.
​
The new treatment facility will employ the use of multiple new odor control measures. Technologies will include the use of chemical additives to help reduce to potential for odor generation within the conveyance system leading to the treatment facility, as well as odor scrubber-type equipment to address odors generated at the treatment facility.
Is the planned treatment technology used by others in the region?
There are multiple treatment systems being evaluated for use on the project. The alternatives selected are proven technologies and will be the best fit for the project based on established economic and noneconomic evaluation criteria.
ENVIRONMENT
What is being done for sustainability?
Sustainability planning is still underway, but there are a number of environmentally sustainable measures that have already been identified for the Nelson Wastewater Treatment Facility (WWTF) design. These include reuse of methane produced during biosolids digestion for heating purposes, high-strength ammonia sidestream treatment, which allows for reduction in the size and cost of the main treatment process, discontinuation of landfilling biosolids through beneficial land application, and high-efficiency motors and lighting. These improvements provide sustainability benefits and save money at the same time.
What are the concerns with ammonia, nitrogen, and phosphorus?
The Environmental Protection Agency and Kansas Department of Health and Environment are requiring stricter limits on our discharge for things such as ammonia, nitrogen and phosphorus. Ammonia is toxic to aquatic life in the receiving stream, and the Nelson Wastewater Treatment Facility (WWTF) will be required to maintain very low concentrations of ammonia year-round. Nitrogen and phosphorus are both nutrients, and when discharged in abundance can contribute to large algae blooms which reduce water quality and can ultimately lead to decreases in dissolved oxygen that harm aquatic life.
FLOODING/STORMWATER
How will the facility rehabilitation impact flooding?
The majority of the improvements will be well above the floodplain. In the few small areas in or adjacent to the floodplain, improvements will be configured so as not to impact flood elevations. While floodplain impact is not a significant issue on this project, care will be taken in the design of improvements to make sure that customers will not be negatively impacted by the project.
Will the new site be susceptible to flooding?
No. All of the improvements will be above the 500-year flood elevation.
Will stormwater improvements be included in the project?
Johnson County Wastewater (JCW) is responsible for the sanitary sewer system. Stormwater services and stormwater improvements are provided by the adjacent cities. While the project does not currently anticipate any stormwater improvements, JCW strives to partner with cities so that we are efficient with projects that we undertake to minimize the amount of time that communities are disrupted by construction activities. The website will be updated as the project progresses to identify areas in which JCW plans to partner with local municipalities should any be identified.
SCHEDULE
What is the construction schedule?
The project will be constructed in phases with various key milestones to allow portions of the existing treatment facility to remain in service. Construction is anticipated to start in early 2024 and be completed in 2029.
Will the plant operate during construction?
The facility will continue to treat all incoming wastewater flow throughout the project duration.