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The Effects of Urbanization
on Water Quality

You can understand why the water quality of our urban water supplies is so important. After all, the majority of the United State's population now live in or near cities. Big cities mean big development over large areas, which can certainly have an impact on the local water supply.

It's not that hard to imagine that as cities grow, things happen that can harm the quality of the local water resources. That is why most governments must take measures to protect rivers, streams, lakes, and aquifers when small towns grow into big cities.

Here are some water-quality issues that relate to urban development.

• Population Growth
• Erosion and Sedimentation
• Urban Runoff
• Nitrogen
• Phosphorus
• Sewage Overflows
• Waterborne Pathogens
• Pesticides

How You Can Help

The EPA has some ideas of things you can do to lessen detrimental effects of urban stormwater runoff:

• Keep litter, pet wastes, leaves, and debris out of street gutters and storm drains--these outlets drain directly to lake, streams, rivers, and wetlands.
• Apply lawn and garden chemicals sparingly and according to directions.
• Dispose of used oil, antifreeze, paints, and other household chemicals properly, not in storm sewers or drains. If your community does not already have a program for collecting household hazardous wastes, ask your local government to establish one.
• Clean up spilled brake fluid, oil, grease, and antifreeze. Do not hose them into the street where they can eventually reach local streams and lakes.
• Control soil erosion on your property by planting ground cover and stabilizing erosion-prone areas.
• Encourage local government officials to develop construction erosion/sediment control ordinances in your community.
• Have your septic system inspected and pumped, at a minimum, every 3-5 years so that it operates properly.
• Purchase household detergents and cleaners that are low in phosphorous to reduce the amount of nutrients discharged into our lakes, streams and coastal waters.

Information in this section is from the U.S. Geological Survey Water-Resources Investigations Report 96-4302, 1996, "Everyone Lives Downstream" (poster). Poster is available by calling 770-903-9100.