Construction sites can be a big source of environmental problems if there isn't good planning to deal with soil erosion and sediment control. Too often it's an afterthought.

“Oftentimes they (project managers) will make a statement, 'well, I'll clean it up when I need too’ and I answer, how do you know when you need too? It's when you see the mud going down the street or something like that and by then it's too late. Enough of that stuff adds up from all the work sites that by the time it gets to a receiving body of water it does an awful lot to degrade the environment,” said Donald Lake, Watershed Management & Soil Erosion Specialist.

Donald Lake is a watershed management and erosion specialist. His goal is to teach construction engineers how to best build on a given site so that the environmental impact from the construction is minimal.

“Most of the time where construction activities take place, you use the soil that's on the site already. In other words, you've stripped the topsoil because you're going to replace it or you're going to put it back down and seed over it,” said Lake.

To prevent erosion problems, that topsoil needs to be returned as quickly as possible with vegetation. Also, after being packed down by the heavy construction equipment the soil needs to be aerated so water will seep into the ground and not become runoff.

He points out soil particles collect pathogens, nutrients and toxics that can be deposited in our waterways when eroded soil is washed away.

“We look at the aspects of controlling runoff, stabilizing soil, that's what we call erosion control and 85% of all planning should be geared toward erosion control not sediment control,” said Lake.

Sediment control is after the fact and that's more difficult with greater risks to the environment.