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Public Works

Phone: 913-715-8300

1800 W Old Highway 56, Olathe, KS 66061

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About Water Quality

What is stormwater and why is it important?

Stormwater is rain or snow that "runs off" across the land instead of seeping into the ground. Runoff is increased from survaces which do not absorb water such as roads, parking lots, and roofs. The storm drains along streets and curbs allow rain and melting snow to move from the streets into a network of manmade pipes and natural channels ending up in our streams and lakes. Stormwater is not treated before it ends up in a stream, lake, or river. Stormwater replenishes our sources of drinking water – lakes, streams and groundwater. Clean stormwater is vital to our quality of life and to the quality of our drinking and recreational waters.

Everyone in Johnson County -- including you -- has an important role to play in keeping our stormwater – and ultimately all our local water resources -- free of harmful pollutants and help Johnson County remain a sustainable community with a plentiful and safe water supply.

The Storm Drainage System and How It Works

The storm drainage system comprises many storm drains, pipes and channels. Storm drains are openings in streets or curbs that are sometimes covered with metal grates. The storm drains allow rain and melting snow to move from the streets into a network of manmade pipes and natural channels. When water flows across yards, streets and other surfaces, it picks up contaminants and carries the runoff untreated to a natural body of water. Dumping wastes into a storm drain or on the ground directly affects the environment, damaging potential sources of drinking water and recreational waters and endangering wildlife and habitat.

Potential Stormwater Pollutants

  • Automotive fluids
  • Litter, including cigarette butts
  • Fertilizer and weed killer from yards
  • Grass clippings, leaves and other yard waste
  • Pet waste
  • Soap, paint, cleaning supplies and other household chemicals
  • Sediment from exposed ground

Stormwater pollution can:

  • Increase the risk of illness and harm to individuals, particularly children, and pets who come into contact with the water
  • Degrade the quality of water we use for drinking, irrigation, recreation and industry; which could cause increased treatment costs
  • Damage the natural ecosystems of our waterways and damage the plant and animal habitat
  • Clog storm drains with sediment and trash and require more maintenance and cause street flooding


Pool Water Disposal

Residential Pool Water Disposal Guidelines

Swimming pool and hot tub water contains many chemcials, including large amounts of chlorine, that are harmful to streams and lakes. Treated pool water is especially harmful to the aquatic life in these waterbodys. If water drained from pools is allowed to enter the storm drain system directly, it can harm fish and other aquatic life. Any water drained to the street or a storm drain flows directly to streams and lakes without treatment, therefore, the guidelines for properly disposing pool water must be followed. 

Releasing chlorinated pool water or backwash filter waste into a stream or storm drainage system is prohibited by City, County, and State regulations. Follow the steps below to safely and legally discharge pool water.

Traditional chlorine pools

Step 1: Discontinue the addition of chlorine 5 to 7 days before you plan to drain the water. This will allow the chlorine to dissipate naturally.

Step 2: Test the chlorine level and the pH of the water. If the residual chlorine level is less than 0.1 ppm (mg/L) and the pH is between 7 and 8, the water is safe to drain. 

Step 3. Drain the water. Direct the water in a way that does not cause it to flow onto a neighbor's property, cause nuisance conditions, or erosion problems. It is preferred that you discharge the water to a grassy area on your property and not allow the water to leave the property. 

Salt water pools

Sanitizing pool water using a chlorine generator is becoming increasingly popular in Johnson County. These systems use dissolved salt (NaCl) in the water and the use of electrolysis to create the chlorine needed to sanitize the water. Pool water treated this way requires slightly different for guidelines for disposal because the residual salt concentrations are too large (usually 3,000 ppm (mg/L)) to discharge to the storm drain system or streams. The State of Kansas acute aquatic life water quality standard for chloride is 860 ppm.  

Step 1: Discontinue the addition of salt. This will stop the generation of chlorine and allow the chlorine in the pool water to dissipate. 

Step 2: Test the chlorine level and the pH of the water. If the residual chlorine level is less than 0.1 ppm (mg/L) and the pH is between 7 and 8, the water is safe to drain. 

Step 3: Drain the water to a grassy area, it cannot be drained to the street or storm drain. When draining to a grassy area on your property take care to not allow the water to flow to trees or landscape beds. Do not allow the water to leave the property from which it originated. All pool water discharge and rinse water must soak into the ground. Typical lawns in Johnson County can tolerate the residual salt contect in the water if you spread the flow out to different areas and water (with tap water) the affected area throughly (1-2 inches) to flush the residual salt through the soil. 

Additional information

Water from backwash filter systems are not allowed in the storm sewer system. It is preferred that this water is directed to the sanitary system through a drain in your home, however, you may discharge the water on your lawn only if all of the water soaks into the ground and no water is allowed to leave your property. Used pool filters should be placed in your trash. 

Contact your city for additional information or questions.

Water Quality

Regulations for preventing stormwater pollution

The U.S. Clean Water Act (CWA) requires water quality standards to be established and enforced by federal and state law. The CWA prohibits the discharge of pollutants from identifiable sources – such as a storm drain – into surface waters without a special permit.

The permit is called the National Pollutant Discharge Elimination (NPDES) permit for the Mulitple Seperate Storm Sewer System (MS4) and are issued by the Kansas Department of Health and Environment (KDHE) to multiple cities and Johnson County. All permit holders are required to prepare a Stormwater Management Plan describing how they will address required program elements, including best management practices, a schedule of activities and the entity responsible for implementation. The six program elements included in the NPDES MS4 permits are listed below:

  1. Public Education and Outreach
    Public education and outreach ensures greater support and compliance for the program. This measure relies on forming partnerships, using educational materials and strategies and reaching diverse audiences.

  2. Illicit Discharge Detection and Elimination
    This measure focuses on decreasing pollutant levels from illicit discharges – illegal pollution – that can significantly degrade water quality and threaten aquatic, wildlife and human health. The measure includes locating problem areas, finding the sources, removing/correcting illegal connections to the storm drainage system and documenting actions taken.

  3. Post-Construction Runoff Control
    Runoff from areas undergoing development/redevelopment has been shown to significantly affect bodies of water. This measure will help prevent damage to aquatic life and property while using the most cost-effective approach to stormwater quality management.

  4. Public Participation/Involvement
    An active and involved community is vital to the success of a stormwater management program. Public input is needed in the development and implementation of the program.

  5. Construction Site Runoff Control
    Polluted stormwater runoff from construction sites often flows to the storm sewer system and ultimately is discharged into local rivers and streams. The introduction of silt and pollutants from construction sites can harm the physical, chemical and biological components of a community's water ways.

  6. Pollution Prevention/Good Housekeeping
    Municipalities conduct many activities that can pose a threat to water quality if practices and procedures are not in place to prevent pollutants from entering the stormwater system.

For fact sheets about each of the six minimum control measures, visit the EPA Web site at http://cfpub.epa.gov/npdes/stormwater/.

Johnson County Kansas Permit and Stormwater Management Plan

The Kansas Department of Health and Environment issued a NPDES permit to Johnson County Kansas in 2014 to regulate discharges into the multiple storm sewer system owned by the County. This permit only covers stormwater discharges into the storm sewer system in the unincorporated area of the County. Most cities in Johnson County also hold NPDES permits with KDHE and are responsible for regulating stormwater discharges within city limits. The permit requires that Johnson County develop a Stormwater Management Plan that outlines how the minimum control measures listed above will be addressed. The permit and stormwater management plan for Johnson County are available at the links below. 

Johnson County Kansas MS4 NPDES discharge permit (February 1, 2014 through January 31, 2019)

Johnson County Kansas Stormwater Management Plan 

Map of area regulated by Johnson County Kansas (grey shaded area)


What Are Your City's Regulations?

Cities in Johnson County have adopted laws to prevent stormwater pollution and protect our community's water quality. Contact your city hall to learn more about your city's specific regulations regarding stormwater pollution prevention.


What You Can Do

Can You Help?

Yes! You can be a stormwater steward. That means in simple, every day activities, like bagging your pet’s waste or taking your car to a commercial wash, you can help keep harmful pollutants out of our waterways.

How to Prevent Stormwater Pollution:

  • Use fewer lawn chemicals and don't water right away. Try using compost instead of chemical fertilizer. Don't water after applying lawn chemicals and don't apply them before a heavy rainfall is predicted.
  • Clean up after your pets. Carry disposable bags while walking your dog so you can pick up and dispose of pet waste in the trash. In your own yard, pick up pet waste, bag it and put it in the trash. Leaving it in the grass sends unsafe bacteria into the storm drains when it rains.
  • Recycle used oil. Find an oil recycling center near your home or work to properly dispose of used oil. Johnson County has more than 30 used-oil recycling sites, such as gas stations, automotive supply stores and lubrication service centers. For a list of sites, go to www.recyclespot.org
  • Sweep driveways and sidewalks rather than washing them off with the hose. Remove grass clippings, dirt and other debris and dispose of it properly.
  • Use a commercial car wash to minimize the effects on the environment . If you wash your car at home, do it on the grass. Use biodegradable, phosphate-free, water-based cleaners only. Use a spray nozzle to save water.
  • Properly dispose of trash and yard waste. Contact your city hall for your community's instructions for proper trash and yard waste disposal.
  • Use household products as directed. Properly store and dispose of all hazardous household products at a hazardous waste facility permitted facility.
  • Shop smart. Purchase and use nontoxic, biodegradable, recycled and recyclable products whenever possible.


Yard Waste Management

Yard Waste Management Frequently Asked Questions

Is it OK to dispose of leaves on stream banks? There are leaves there already and I've heard it helps to stablize the stream bank. No-- It is true that there are trees and other vegetation next to streams and leaves from those trees fall into and around the stream, but as with many things in life, too much can be a bad thing. The natural system is equipped to break down and process the leaf litter that is there naturally, but dumping leaves in or near a stream overwhelms the system. Too much decomposing organic waste adds excess nutrients into our streams and lakes that can lead to unsightly algae blooms which also can be harmful to pets and humans. As algae dies, it uses oxygen in the water, which causes depletion in oxygen in the water for aquatic life and can cause fish kills. 

Is it OK to put leaves in the storm drain? No-- it is illegal to dump anything, other than clean water, into the storm drain. Not only is it bad for water quality because stormwater is not treated, it can cause clogs in storm water catch basins which could result in localized street floodiing. And this causes increased maintenance costs for your city, which could result in higher taxes for you. 

Will mulch mowing leaves cause thatch in my lawn? I'm worried because have several mature trees in my yard. No-- research from Michigan State University Hancock Turfgrass Research Center has shown that you can mulch up to 6 inches of leaves into your lawn. To do this effectively, it is best to stay ahead of the leaves and not try to mulch 6 inches at once, but mulch frequently throughout the fall season. Also, make sure and have your mower blade sharpened before the fall season to ensure effective mulching. Research has shown that core aeration and fertilizing your lawn with a fertilizer that has a high nitrogen (N) and low phosphorus (P) content will help break down the leaves into a useable resource for your healthy lawn. (When purchasing fertilizer, check the Nitrogen (N), Phosphorus (P), and Potassium (K) contents. Lawns in Johnson County generally do not need additional phosphorus.) 

Additionally, thatch is not caused by mulching leaves or grass clippings into your lawn. Thatch is caused by many factors which include, frequent and shallow watering, excessive use of nitrogen fertilizer and pesticides, compacted and poorly aerated soils, and infrequent, high mowing. 

Is it OK to blow or rake my leaves into the street-- doesn't the city pick them up? Most cities in Johnson County do not offer a leaf removal service. The street sweepers you may see on your street are there to pick up the leaves that fall on the street and ONLY those leaves that fall on the street. They are not equipped to remove a large amount of leaves, such as those raked intentionally from a yard, The cities of Westwood, Westwood Hills, and Roeland Park do offer a city-wide leaf pick up service, but only on specific days. Contact your city for details. The cities of Fairway and Mission Hills have negotiated on behalf of their residents with a third-party contractor to provide a fee-based leaf-collection service. Most other cities in Johnson County have weekly curbside yard waste collection, but require leaves to be in paper bags or in a container clearly marked as yard waste. 

Visit http://bit.ly/loveryourlawn to learn more.