Skip to main content
U.S. flag

An official website of the United States government

Here’s how you know

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

HTTPS

Secure .gov websites use HTTPS
A lock (LockA locked padlock) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

    • Environmental Topics
    • Air
    • Bed Bugs
    • Chemicals and Toxics
    • Climate Change
    • Emergency Response
    • Environmental Information by Location
    • Environmental Justice
    • Greener Living
    • Health
    • Land, Waste, and Cleanup
    • Lead
    • Mold
    • Pesticides
    • Radon
    • Science Topics
    • Water Topics
    • A-Z Topic Index
    • Laws & Regulations
    • By Business Sector
    • By Topic
    • Compliance
    • Enforcement
    • Guidance
    • Laws and Executive Orders
    • Regulations
    • Report a Violation
    • Environmental Violations
    • Fraud, Waste or Abuse
    • About EPA
    • Our Mission and What We Do
    • EPA Administrator
    • Headquarters Offices
    • Regional Offices
    • Labs and Research Centers
    • Planning, Budget, and Results
    • Organization Chart
    • EPA History
    • Staff Directory
Nutrient Pollution
Contact Us

Sources and Solutions: Stormwater

Rain and snow flow over streets, parking lots, and roofs collecting excess nutrients and pollutants before entering into a storm drain or water body.
Because stormwater flows over hard surfaces directly into storm drain, there is no opportunity for soil and plants or a water treatment facility to filter out pollutants.

In undeveloped areas, precipitation typically soaks into the ground. When buildings, parking lots, roads and other hard surfaces are added to the landscape, the ground cannot absorb the water. Water from rain or snow storms, known as stormwater, instead flows over streets, parking lots and roofs and into a water body or storm drain.

Stormwater runoff is often worsened by human activities, and can contain nitrogen and phosphorus pollutants from fertilizers, pet and yard waste. Because stormwater flows over hard surfaces directly into a water body or storm drain, there is no opportunity for soil and plants or a water treatment facility to filter out pollutants. Urban and suburban areas produce much more stormwater runoff due to the high amount of paved and hard surfaces.

During periods of heavy rainfall or snowmelt, some wastewater systems are designed to occasionally overflow and discharge excess untreated sewage directly to nearby streams, rivers or other water bodies. These discharges are known as combined sewer overflows and are common in many cities nationwide.

Green infrastructure can be used to address stormwater runoff and sewer overflow problems. Green infrastructure works by slowing down the runoff, spreading it out over the land, and slowly soaking it into the ground, or in some cases reusing the water onsite. Green infrastructure is also sometimes referred to as low impact development. These techniques also help to remove pollutants from runoff, buy allowing plants to filter out pollutants as the water slowly infiltrates into the ground. Some examples of green infrastructure techniques include rain gardens, pervious pavement, rain barrels, and green roofs.

Learn more about what you can do to reduce stormwater runoff in your yard.


A Drop's Life

  • Nutrient Pollution
  • The Problem
  • Sources and Solutions
  • The Effects
  • Where This Occurs
  • What You Can Do
  • Policy and Data
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on March 30, 2023
United States Environmental Protection Agency

Discover.

  • Accessibility Statement
  • Budget & Performance
  • Contracting
  • EPA www Web Snapshot
  • Grants
  • No FEAR Act Data
  • Plain Writing
  • Privacy
  • Privacy and Security Notice

Connect.

  • Data.gov
  • Inspector General
  • Jobs
  • Newsroom
  • Open Government
  • Regulations.gov
  • Subscribe
  • USA.gov
  • White House

Ask.

  • Contact EPA
  • EPA Disclaimers
  • Hotlines
  • FOIA Requests
  • Frequent Questions

Follow.