RALEIGH — Some of North Carolina's waterways are littered with pollution from construction sites, or agricultural runoff, or people's disregard for our natural resources. Now, the state is trying to do something about the problem by visiting every construction site in the Crabtree Creek watershed.

The site of a new Cardinal Gibbons school is an example of how a construction site can prevent polluting a nearby waterway. The site includes a silt fence to hold dirt back, newly planted grass to prevent erosion, and a rip-rap consisting of rows of rocks laid out in such a way as to slow the flow of rain water.

There are many construction sites, however, that don't comply with environmental guidelines such as these. Construction at the Centennial Arena site, for instance, has already impacted a nearby creek. Much of the vegetation that was growing on its banks has disappeared. At one point, the project did not have the proper sediment controls in place, which allowed soil to wash into the creek.

The state served the construction company with a violation notice, and the site is now in compliance, but officials say oversight on this and other projects needs to be improved.

Tuesday's sweep of the Crabtree Creek area also serves to bring attention to the fact that more people are needed to enforce the rules as the region continues to experience explosive growth.

Mell Nevils, chief of Land Quality, says the state has a proposed plan of action that would provide that extra help.

The reason there is so much concern about sediment control is that many things can be affected by runoff, including drinking water, real estate values, fish and shellfish, and boating.