Department of Water Resources Spokeswoman Amanda Winks says during this time of year when it rains more frequently, pollutants can get washed into the storm drains.
The pollutants can then go into the city's river and creeks. She says paint, oil and pet waste are some of the common pollutants they see.
Winks says some of the hazardous materials that go into storm drains are done so intentionally. If you see anyone dumping anything other than water into the storm drain it is important to report it immediately.
If you suspect or see an illicit discharge occurring, please call: