What is polluted runoff?

Water from rain and melting snow either seeps into the ground or “runs off” to lower areas, making its way into streams, lakes and other water bodies (rivers). On its way, runoff water can pick up and carry many substances that pollute water. Some - like pesticides, fertilizers, oil and soap – are harmful in any quantity. Others - like sediment from construction, bare soil, or agricultural land, or pet waste, grass clippings and leaves - can harm creeks, rivers and lakes in sufficient quantities.

In addition to rain and snowmelt, various human activities like watering, car washing, and malfunctioning septic tanks can also put water onto the land surface. Here, it can also create runoff that carries pollutants to creeks, rivers and lakes. Polluted runoff generally happens anywhere people use or alter the land. For example, in developed areas, none of the water that falls on hard surfaces like roofs, driveways, parking lots or roads can seep into the ground. These impervious surfaces create large amounts of runoff that pick up pollutants.

The runoff flows from gutters and storm drains to streams. Runoff not only pollutes' but erodes stream banks. The mix of pollution and eroded dirt muddies the water and causes problems downstream.

Show All Answers

1. Why all the fuss about stormwater now?
2. What is stormwater runoff?
3. What is polluted runoff?
4. What is nonpoint source pollution?
5. What causes polluted stormwater runoff?
6. Why do we need to manage stormwater and polluted runoff?
7. How is stormwater and runoff "managed"?
8. If it only affects streams and creeks, why should I care?
9. What is a stormwater fee and why do I have one?
10. How does this benefit the average taxpayer?
11. What can I do to make a difference at home and reduce the amount of stormwater pollution?
12. How else can I help reduce stormwater pollution in my area?
13. What is a catch basin or storm drain?
14. Are sewers and storm drains the same things?
15. Do catch basins and storm drains get cleaned out?
16. Why doesn't the City of Saint Peter clean out all of the storm drains before a storm?
17. Why doesn't the City of Saint Peter install filters or screens in front of the catch basins?
18. Why isn't a net/fence/barrier installed at the end of the storm drain channel to catch all of the trash?
19. What kinds of pollutants are found in the storm drain system?
20. What should I do if I see a neighbor throwing trash, used oil or paint into a storm drain?
21. How can I properly dispose of left-over paints, thinners, chemicals, etc.?
22. Is it okay to wash my car on the driveway if I use a biodegradable soap?
23. Yard clippings and leaves are natural, so they don't cause any problems, right?
24. Is there a fine/penalty for illegal dumping?
25. How does pet waste left on the grass affect stormwater?