Water Quality
Stormwater management is essential for preventing soil erosion and flooding of inhabited areas. It is also vital in ensuring safe drinking water resources. In this section, access information on stormwater management and water quality. Learn all about incorporating and maintaining green infrastructures, investigating stream health, and creating an infiltration surface. Tips on green roofs, rainwater cisterns, and live staking can be found as well.
Stormwater Management, Flood Control, and Water Quality
Stormwater is rainwater that runs off roofs, lawns, and driveways and enters storm drain inlets. Along its way, stormwater can pick up various pollutants, such as fertilizers and pesticides. As it’s usually piped directly into local streams and rivers without any treatment, stormwater can lead to waterway pollution. In turn, polluted runoff can have a direct impact on drinking and residential water quality.
Increased stormwater runoff – along with impermeable surfaces in urban areas – can further lead to significant property damage and floods. This is why, over the past decade, stormwater management efforts have focused on improving the runoff’s quality. One way of accomplishing this is by directing the site runoff to low impact development practices.
Infiltration is among the most effective management practices for improving stormwater quality. It involves infiltrating stormwater into the soil or passing it through a soil/media mix such as compost or mulch. Infiltration allows stormwater to become part of the soil-water matrix, where microbes can break down organic forms of carbon and nitrogen. Also, the soil helps remove sediment, pathogens, and other particulates from the stormwater.
Other ways to control the movement of stormwater runoff and keep waterways clean include growing riparian buffers, implementing green infrastructure practices, and planting vegetated swales.
Stormwater Pollutants
As stormwater does not undergo any treatment, it can easily carry harmful materials into streams, rivers, ponds, wetlands, and other waterways. In general, stormwater pollutants are grouped into five main categories – sediment, solid waste, nutrient-rich materials, pathogens, and toxic materials.
Sediment is the largest volume pollutant. It typically comes from soil erosion and is most prominent in construction site runoff. The source of sediment pollution, however, can be any soil that is not protected from rainfall or runoff. Sediment poses a great water quality risk as it often carries other pollutants, such as bacteria, nutrients, and organic chemicals.
Other major stormwater pollutants include nitrogen and phosphorus. These nutrients can cause plant blooms in streams and rivers, including harmful algae blooms. Nutrient-rich pollutants also lower oxygen levels in state waterways, causing harm to fish and other aquatic life. Common sources include excess fertilizer applications and eroded soil.
Tips and Advice on Stormwater Quality
On this page, discover Penn State Extension resources on improving water quality, protecting water supplies, and keeping contaminants out of waterways. Gain a deeper understanding of common water pollutants through webinars on topics such as nitrates in private water supplies and iron, manganese, and hydrogen sulfide water quality issues.
- News
National Municipal Stormwater Alliance Establishes "National Stormwater Day"
Date Posted 11/17/2023NMSA announces the new holiday this November to celebrate the date the MS4 Phase 1 program began. - Articles
Environmental Hazards of Road Salt
Did you know that runoff containing de-icing chemicals can damage our rivers and streams? - Videos
How Can I Manage My Lawn to Reduce Nutrient Pollution?
Length 4:13To protect water resources, we need to reduce the amount of lawn nutrients we add. Find out what you can do. - Videos
What Are Nutrients and Why Are They Stormwater Pollutants?
Length 4:54Excessive nutrients can harm water quality. What are the common nutrients that cause concern and how do they cause water quality problems? - Articles
Planting Along Streams
If you have a stream on your property, even it's small, you have the opportunity to both enhance your landscape and protect precious water resources. - Articles
What is an MS4?
Municipal Separate Storm Sewer System refers to a collection of structures designed to gather stormwater and discharge it into local streams and rivers. - Articles
Sinkholes and Underground Cavities Due to Human Activity
A sinkhole is one of several things that can lead to land subsidence, where the ground sinks gradually or suddenly. - Videos
Why Use a Rain Barrel?
Length 6:11Homeowners can reduce stormwater runoff on their property by installing rain barrels under downspouts. The captured water can be used various ways around the landscape. - Articles
What is Stormwater?
While you may be familiar with the term, have you ever wondered what stormwater is? - Articles
Why Should I Care About Stormwater?
Does stormwater really affect me? Why should I care? Whether you live in a town, the country, a city, or the suburbs – when it rains, the water that runs off needs somewhere to go. Stormwater affects everyone! - Articles
What are Stormwater Pollutants?
Stormwater can cause water pollution because it often contains harmful materials picked up when it washed across the land. - Articles
What is Sediment and Why is it a Stormwater Pollutant?
Sediment is a stormwater pollutant that is made up of soil particles that have been detached from the land by erosion and is Pennsylvania's largest surface water pollutant by volume. - Articles
What's Allowed to Go in a Storm Drain?
The storm drains along your street most likely lead directly to a nearby stream. Dumping anything in them besides clean water is an illicit discharge. - Articles
Municipal Staff and Elected Official Stormwater Training Needs
In communities with stormwater permits (MS4), there is a need for everyone representing the township, city, or borough to be able to answer basic questions about stormwater management plans. - Articles
What is a Municipal Stormwater Fee?
The stormwater systems most of us take for granted are getting more expensive to design, construct and maintain. - Articles
Using Biochar for Water Quality
Though it has been around since the times of ancient tribes, biochar is only recently becoming a popular topic of discussion among modern home gardeners, commercial farmers, land managers, and wastewater treatment operators. - Articles
Understanding Transparency Tube Measurements
Transparency tubes are popular for use in stream monitoring programs. They are also part of the "First Investigation of Stream Health" activity. - Videos
How Do Trees Reduce Stormwater and Flooding?
Length 6:18Explore how trees help manage stormwater runoff that impacts our communities. - News
Slow the Flow: Reduce Stormwater on Your Property
Date Posted 11/12/2021Intensified rain events and increased development can result in many negative impacts to communities. - Webinars
Backyard Stream Repair Series
Join this virtual series to learn simple and affordable techniques to help repair your stream. - Guides and Publications$60.00
Rain to Drain: Slow the Flow Activity Kit
Save time preparing to teach youth and adults about stormwater with this kit of hands-on materials needed to implement the Rain to Drain: Slow the Flow curriculum from Penn State Extension. - Webinars
Free
Recognizing Efforts to Keep Your Community's Water Clean
When Watch NowRecorded Jun 9, 2020Whether on a farm, in your residential neighborhood, or on public lands, this informative event will cover how to protect one of our most essential resources, water. We will discuss popular best management practices for water quality, how to identify them, and how these practices keep our water clean. - Guides and PublicationsStarting At $16.20
Rain to Drain: Slow the Flow
Rain to Drain: Slow the Flow is a hands-on stormwater education curriculum available from Penn State Extension and Pennsylvania 4-H.