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Phone: 913-715-8500

11811 S. Sunset Drive, Suite 2500, Olathe, Kansas 66061

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Education: Treatment

Let's begin by learning how Johnson County collects wastewater and transfers it to a treatment facility:

1. Collecting wastewater 

What's the first step in treating wastewater?

Johnson County Wastewater and other wastewater treatment organizations clean used water in almost the same way that nature would, only we speed up the process. If the water was left alone in a stream or lake, it would naturally clean itself, but that could take a long time. The first thing we have to do, then, is collect the wastewater and transport it to a wastewater treatment plant.

The transfer system

Wastewater leaves your home through a service line that collects waste from sources like toilets, sinks, and dishwashers. It flows from the service line to a larger "main" sewer line that transports the flow to one of our wastewater treatment plants. In Johnson County's system there are slightly more than 2,200 miles of sewer line. They are usually made of plastic, iron, or clay. Sewer manholes allow us to access the sewer lines to inspect and clean them. Manholes can be very dangerous. Only Johnson County Wastewater personnel should open and enter them!

Sanitary sewers are not designed to carry rainwater, only used water from homes and businesses. Rainwater goes into storm sewers and creeks. You can see storm sewer inlets along the curb on many streets. Johnson County Wastewater uses pump or lift stations to help carry the wastewater to one of our plants. Lift stations are needed to pump the sewage to a geographic high point where gravity takes over and sewage flows to a treatment plant. After the wastewater reaches the plant, the treatment process begins! The first step is "Preliminary Treatment."

2. Preliminary Treatment

Usually, the first thing that happens at the treatment plant is the used water goes through a bar screen. The screen catches and removes large things from the water (such as paper cups, leaves, and sticks). The water goes through a grit removal chamber which removes heavy things like gravel, seeds, and coffee grounds (grit). When the water enters the chamber, the “grit” settles to the bottom and is removed. The material removed by the screen and grit chamber is usually disposed of in a landfill. The water then flows to the next stage of treatment - "Primary Treatment."

3. Primary Treatment

After grit and large solid materials are removed from the wastewater, many smaller solid particles still remain. To remove these particles, the wastewater is sent through large tanks called "clarifiers". In the clarifier, the flow moves very slowly and small solid particles settle to the bottom and are removed. This process is called "sedimentation". The material that is removed is called sludge. The sludge is treated separately. The remaining wastewater contains mostly dissolved wastes and goes to the next stage - "Secondary Treatment."

4. Secondary Treatment

The work of Secondary Treatment is a biological process accomplished by living organisms. Bacteria and other microscopic organisms grow by using the waste for food. This is a common process which occurs in nature. At the treatment plant, we just speed up the process. Wastewater treatment facilities create a utopia for microorganisms: optimal food, optimal oxygen, and plenty of space to grow. As the microorganisms feed on the waste we’ve flushed away, they grow and divide - very happily! And as the organisms feed and grow, the water is being cleaned. Microorganisms that feed on the waste in the water are "bacteria" and "protozoa." We sometimes call them the “bugs.” The wastewater has lots of food to help the microorganisms grow, but they also need lots of oxygen. The wastewater itself doesn’t have very much oxygen, so we have to make sure the environment has plenty of oxygen for them.  Johnson County Wastewater uses two methods of making a good environment for the microorganisms to eat and grow, in turn, cleaning the water.

Trickling Filter Methods

At some of our treatment plants, we use "trickling filters" which pour water over tanks filled with rocks. The microorganisms live on the rocks which are surrounded by air. As the wastewater trickles past them, they eat the waste and grow. This trickling of the water also provides oxygen so the microorganisms can thrive.

Activated Sludge Method

Some of our treatment plants grow microorganisms in large tanks. Air is blown into the tanks full of wastewater and microorganisms to add oxygen to the environment. The air is bubbled in the water and mixes food and oxygen together for the “bugs.” When wastewater is treated in this way, we are using the "Activated Sludge Method." With all of this food and air, the microorganisms grow and multiply rapidly. It's not too long before the population of "bugs" is too large, and some must be removed in order to make room for new "bugs" to grow. The excess "bugs" are removed by sedimentation in the same kind of tanks used for Primary Treatment. In the tank, the "bugs" sink to the bottom and they are removed. The settled "bugs," along with settlement in the primary stage are both referred to as "Activated Sludge." The sludge is treated separately. The remaining wastewater is now much cleaner. In fact, after Primary and Secondary treatments, 85 percent or more of all pollutants in the wastewater have been removed. The remaining wastewater moves on to "Tertiary (meaning third) Treatment."

5. Tertiary Treatment


Before we release the treated water back to a stream or river, we kill any microorganisms that might cause disease. At some of our facilities, we use a solution that contains chlorine to kill them. Extra chlorine left in the wastewater is then removed by another chemical. At other facilities, we use ultraviolet (UV) light to disable and kill the microorganisms.


Where does wastewater go when we’re done? After the wastewater is cleaned, we put it back into a stream or river where it’s safe for fish to live and animals to drink. Wastewater that is cleaned and sent back to the streams is called "Effluent."


Education: Staff - In the Trenches

Did you know that according to the article entitled 10 Jobs Americans Can't Live Without by Charles B. Stockdale from 24/7 Wall St., Water and Wastewater Treatment Plant jobs are second only to Registered Nurses!

Johnson County Wastewater staff are members of an exclusive club, a kind of Sewer Surfer’s Club! Each one has an important job to do so that wastewater is clean and safe for our community. There are five general areas ranging from surfers/treatment to lifeguard/engineering; each member is always concerned about clean water.

1. Surfers (Treatment) - You know what surfers do. They're always on the beach, waiting for the next wave. At Johnson County Wastewater, our "treatment" members are like surfers - they're always waiting for the next wave (flow) of wastewater to come to the plant. They ride that wave until the entire wastewater treatment process is completed. That means watching all the controls, pipes, pumps, and valves, as well as chemicals that are necessary to clean the wastewater. Making sure everything is working together to clean the water is an important job of the treatment crew members.

2. Beachcombers (Line Cleaning) - Beachcombers are always picking up things from the beach. Some of our Surf Club members do that with the sewer lines - they clean them! They can do this by using a "jet-rodder" which is like a big saw with water that goes through the sewer line and removes large items such as tree roots. Or, they can use a "jet-vac" which is like a huge vacuum cleaner. It's awesome!

What happens ...when fats, oils, and grease are poured down the drain? It sticks to the sewer pipe walls creating layers of buildup that restrict the wastewater flow. True, this is an extreme case, but see what our friends across the pond ran into!

3. Beach Patrol (TV Crew) - Now, when our staff members say they work on a TV crew, some people have another vision. But what do you think the beach patrol does? That's right! They're the ones making sure everything is safe and in order. Our crews send a video camera down into the sewer lines to make sure that they're all working right and that there are no cracks or leaks in them.

Test your knowledge by answering this question from the Water Environment Federation (the correct answer is at the bottom of this page):

* Reasons for a closed-circuit television (CCTV) inspection for preventive maintenance include identification of and rating of pipe defects, system condition assessment, and what else?

  1. prioritization of future capital improvement projects, based, in part, on information gathered during CCTV inspections
  2. keeping crews busy when other equipment is broken
  3. making sure the sewer cleaning crews are getting the pipes clean

This function helps Johnson County Wastewater know which lines should be fixed so that all the wastewater arrives safely at the treatment plant. Cool, huh?

4. Surf Shop (Maintenance) - So, let's say your surfboard needs to be fixed. Bummer! So what do you do? You go to the surf shop. Johnson County Wastewater has a surf shop of its own called Maintenance. We actually have two groups of club members who make repairs – one group works on the lines (called line repair) and the other group works on the wastewater processing facilities. Members of both groups are very important because they make sure EVERY piece of equipment or sewer line is in good working condition.

5. Lifeguards (Engineers)  - Lifeguards are important at the beach. At Johnson County Wastewater, our engineers are like lifeguards. They keep an eye on the big picture and come up with new and better ways to treat wastewater. That could mean building more treatment plants, putting in new sewer lines, or repairing what we already have. Engineers make sure that it's all going to work. They watch over projects and help the other Johnson County Wastewater staff members do their jobs.

That wraps up the introduction of the surfing crew at Johnson County Wastewater. You can probably see why we are the largest department in the county! There is lots to do and always something new to learn. We're proud of our role; helping to preserve the quality of life for all of who work, live, and play in Johnson County!

Interesting links

This page gives you a more detailed view of some of the jobs performed by our staff members.


* The answer to the CCTV question is 1. Information from CCTV inspections is used to help prioritize sewer projects and future funding needs.

Education: Resources

The following links offer fun and interesting information about water and wastewater treatment:

Bristolwater Water Treatment in England
Information, questions, and pictures about the water cycle

EPA, Environmental Protection Agency
Comprehensive sections on Wastewater Technology, Wastewater Management, and Wastewater Infrastructure

ESRI, Environmental Systems Research Institute
ESRI, a prominent GIS and mapping software manufacturer, provides extensive information for schools

Highline Water District in Seattle, Washington
Fun facts about water

Kansas Department of Health and Education
Kansas Kids Can Newsletters

Microbe Zoo
Comm Tech Lab's website by Michigan State University offers exploration of microbes. A major attraction is Water World which includes bacteria, algae, methane producers, and more.

U.S. Geological Survey's Water Science School
Guide describes what happens at each stage of the treatment process and how pollutants are removed.

Wally Creates a Lego Wastewater Wonderland 
A youngster learns the treatment process with classic toys

Water District of Portland, Maine
Just for Kids page offers Story Time, Coloring Book, Cool Pursuits, and Knowledge Quest

Water.Org: Clean Water Means Healthy Kids
Committed to providing clean drinking water to communities in developing countries

Education: Overview

Johnson County Wastewater's Mission Statement

Protecting our environment * Serving our customers * Enhancing our community

We know we are doing our job well when our customers can "flush and forget." But for those of you who have a deeper interest in the wastewater industry, we hope that you will find this section to be informative and interesting!

What is “wastewater"?

Wastewater is “used” water. Almost everyone thinks about the obvious (“SHHHHH” – flushing the toilet), but used water is any water that goes down the drains in your house. If you turn on your faucet and wash your hands, run the garbage disposal, take a shower, or run the dishwasher, once it’s in the drainpipe, it becomes wastewater, which is also called sewage.

What is "wastewater treatment"?

Before the used water can be put back into rivers and streams, it needs to be cleaned. The process of cleaning the used water is called wastewater treatment. Treating the wastewater helps make the rivers and streams safe for people, fish, plants, and other living things. Sometimes we call treatment a “defense” against water pollution.

Before modern treatment

The idea of collecting and treating wastewater is one of the more important ideas in history. Before modern wastewater treatment methods were established, wastewater went directly into streams and rivers – the same streams and rivers where people took baths, washed clothes, and got drinking water. Because of this, many people suffered from diseases caused by contaminated water. Diseases such as cholera, typhoid, and diphtheria were common.

Wastewater treatment policies

Wastewater treatment of some kind has been practiced in the United States for over 100 years, but it was only recently (since the 1970’s) that strict standards for clean water were established. These two bills govern the activities of treatment plants nationwide and establish the standards by which they operate:

  • In 1972, Congress passed the Clean Water Act to restore and maintain the quality of our water.
  • In 1987, Congress reauthorized the Clean Water Act to support water quality programs.

Does everyone have a role in conserving the supply of clean water?

YES! Treatment plants spend a lot of time cleaning water that was never used in the first place. It’s everyone’s job, as a consumer of natural resources, to help conserve water. To help you appreciate the importance of this valuable resource, we’d like to tell you a little about wastewater in our educational section: how wastewater is processed to become the clean water you depend on every day; our staff and their range of skills and knowledge; plus our tours, games and activities that are available.

Education: Microbes

Wastewater Microbes and Organisms

In nature and in a wastewater treatment plant, organisms are the key players in keeping our water clean. The following photographs provide a general sampling of the organisms involved in the cleansing process. Under a microscope, a variety of organisms can be observed having different sizes, shapes, life cycles, mobility, and roles. 

Click on a photo below to view an enlargement in a new window.

Bacterial Filaments


Using a phase contrast microscope, living bacteria can be visualized quite well. Some are motile and may swim across the field of view, while others may appear to vibrate or drift.

Rod-shaped, Filamentous Bacteria, shown here, have been referred to as "sewage fungi."


Protozoa - Amoeba

Ameoba Shell

Several groups of protozoa are represented in wastewater treatment plants. These include amoeba, stalked ciliates, crawler ciliates, free swimmers, and flagellates.

The primary role of protozoa is to clarify the effluent through predation on bacteria.

Amoeba come in two forms, shelled and without a shell. Here is a common shelled one, Arcella. The shell is composed of tiny sand grains.

Amoeba PodHere's a common Amoeba without a shell. The body shape changes with movement. They don't have cilia.


AmeobaThese are also common, don't have a shell, and are very tiny in comparison to the other types of Amoeba.




Protozoa - Stalked Ciliates

Single CiliateSingle Stalk Ciliate consume food via vorticellids, oral cilia that wind completely around the top of the cell. The stalk contains a contractile, slightly sinuous filament that can rapidly coil up like a spring, pulling the cell body down.




SheathedSheathed Stalked Ciliate secrete a lorica, an outer membrane that protects the ciliate.


Colonial CiliateSeveral types of Colonial Stalked Ciliate commonly occur in wastewater treatment plants.





Protozoa - Crawler Ciliates

CostataThese are two different Crawler Ciliates. They are called crawlers because they "crawl" over surfaces such activated sludge floc so they can find bacteria to eat. They don't free-swim very well.

The side view of Euplotes shows the "setae" which act as their legs. Both Euplotes and Aspidisca are common in activated sludge and their presence is desired as they indicate that a plant is operating as it should.


Protozoa - Free Swimmers

LitonotusThese are two common free swimmers in activated sludge. They have cilia all over the body which allows them to swim freely through the water. They feed on bacteria.


Protozoa - Flagellates

PeranemaThis is one of the largest Flagellates found in activated sludge...so you can imagine the difficulty of photographing the smaller ones! This one has a long extended flagella and another that lays along the body. The flagella enables movement as well as the ability to catch food by pulling bacteria down to its "mouth" where the flagella attaches to the body.

There are two primary groups of Flagellates. The Peranema belongs to the group which ingests its food. The other group of Flagellates is more like bacteria. They don't ingest whole food. They take in food that is already partially "digested."




These images are of the same genus of Rotifer and are the most common in activated sludge. Rotifers are multi-celled animals which draw in chunks of bacterial floc to feed on.



ColurellaThis type of Rotifer is also fairly common and has a shell around it. Some have shells, others do not. The presence of Rotifers in activated sludge generally means a good, stable sludge with plenty of oxygen.





Worms - Aquatic Earthworms

Aquatic earthworm

Aquatic Earthworms are very much like the earthworms in our yards, but these live in an aquatic environment. The earthworms in a yard can't live in that type of environment...as is obvious every time the ground becomes saturated from rains. Worms come out en masse...much to the delight of robins.

Aquatic wormAquatic Earthworms have setae along the body which allows them to tunnel through the floc particles, ingesting chunks of bacterial floc. They are quite common in old activated sludge.





Worms - Nematodes


Roundworms (Nematodes) are also common in activated sludge. Unlike aquatic, they are not segmented and their intestines are straight (earthworms have convoluted intestines, like us). Roundworms also feed on chunks of bacterial floc.

The Roundworms seen in wastewater treatment plants are "free living," that is, they are not parasites. Most people are familiar with the intestinal roundworms people and pets get, as well as those that are plant parasites. Roundworms do not have the setae like earthworms and move through the substrate by whipping their body back and forth.