Sediment

Sediment pollution in a river

Sediment Pollution Process

Did you know that sediment is the Number 1 National pollutant source? Sediment is commonly picked up in rain and snowmelt runoff as well as during stream erosion when swiftly moving stormwater scours away stream beds and erodes stream banks increasing sediment load within the river. Increased sediment has a devastating effect on our rivers ecosystems. It not only carries harmful pollutants such as phosphorous, it buries aquatic insect life and suffocates fish.

Suspended Solids - Sand

In Aspen, the concentration of suspended solids in stormwater runoff is of special concern. At times the amount of total suspended solids measured in stormwater runoff has been over 55 times the national average.There are three main contributors to the high levels of sediment in Aspen stormwater. The first is due to the steep nature of the area. The slopes that surround Aspen are more likely to erode. Because of the steep terrain, soil is likely to be carried by runoff. Construction that disturbs soil within the city limits is another contributor of sediment in stormwater. Sand that is used to de-ice roads also eventually ends up in the river. In the spring, when roads begin to thaw, all the sand used throughout the winter is collected by stormwater and carried to the river.

Silt fence along a ridge line next to a riverReducing Impact

Certain measures have been taken to reduce the amount of sediment that enters the river system. Aspen's Urban Runoff Management Plan details the measures developers must take to ensure no sediment leaves their site. These actions help prevent sediment from getting to impervious surfaces outside the construction site where they can be easily washed away into storm drains and local water bodies. Installing silt fences, drain covers, hay bales, and covering piles of loose sediment during construction are all techniques used to keep sediment out of stormwater.

Drain cover at curbsideStormwater Vaults

The City of Aspen also has stormwater vaults located above the Jenny Adair Wetlands, and at the Rio Grande Recycle Center. These vaults hold storm water which allows sediment to settle to the bottom. The water is then released to the river with a much lower concentration of sediment.

Sweep Instead of Washing

It takes the effort of everyone within Aspen to clean up after themselves and keep sediment out of stormwater and out of the river system. Instead of washing driveways into the street, take the time to sweep up sediment and dispose of it properly.