(Source: Water on the Web, http://waterontheweb.org)
Erosion and sediment control is an important part of how we protect the environment. Sedimentation (the settling of material carried by wind and water in to our waterways) can destroy fish habitat and affect our water supply, infrastructure, flood control, navigation and recreational activities.
Most construction activities result in major modifications to the landscape. The removal of soil stabilizing vegetation and the exposure and compaction of fine grained soils can result in stormwater run-off and soil erosion rates that are orders of magnitude greater than natural rates. The International Erosion Control Association (IECA) indicates that, in the absence of practices to manage run-on, runoff, erosion, and sedimentation, the production of eroded sediment is typically 200 to 400 times greater on construction sites versus undisturbed conditions.
Turbidity refers to how clear the water is. High concentrations of particulate matter can modify light penetration, cause shallow lakes and bays to fill in faster, and smother benthic (bottom of a lake) habitats- impacting both organisms and eggs.
The protection of exposed surfaces from the erosive energy of rain splash and surface run off flow should be the primary goal when selecting appropriate control measures. Ensure the sole focus is not on attempting to remove fine sediment from run-off using sediment controls (detention, settling, filtration); these practices are only effective as a secondary line of defence.
Soil cover is the easiest and most cost-effective erosion control factor that can be managed on a construction site. New practices and technologies are constantly being developed. A few standard practices today are:
1. Mulch: hay or straw
2. Grass: Seeding and Sod
3. Erosion Control Blankets
4. Co-Polymer Soil Stabilizers
The purpose of source control is to prevent or minimize the detachment, entrainment and transport of sediment. Good planning and implementation of temporary and permanent erosion control practices reduces the need for expensive, high maintenance sediment control and delivers significant cost savings and better compliance with environmental regulations. (City of Calgary, Guidelines for Erosion & Sediment Control 2011)
With a little planning and education we can greatly improve some of the negative impacts we have on our environment.