Waste from chemicals and materials used in construction, and soil that erodes from construction sites can pose a problem.

Here are a few tips for preventing harmful contributors to stormwater pollution from a construction site:

Wash waters from concrete mixers should be disposed of back at the contractor's site or deposited into a large hole dug into the site, which would be big enough to contain all the wash waters. Concrete truck chutes should never be rinsed out with a hose and allowed to run directly into the storm drains.
Waste storage for used oils, solvents and other hazardous fluids must be under cover with secondary containment in case of a spill and to prevent rainfall from contact that would wash hazardous fluids into nearby waterways.
Landscaping and earthmoving can all contribute to soil erosion. Silt fences hold back loose soil and sand when it gets windy, which help keeps sand and soils from being blown into street gutters where rainwater can wash it into storm drains.
Engine repairs or preventive maintenance such as oil changes may take place at the construction site and pose a problem. Maintain a “dry site” by using off site facilities, performing work in designated areas only, providing cover for materials stored outside, containing and cleaning up spills immediately, and training employees and subcontractors.