Sediment is the natural process of rocks and soil particles breaking down and being transported by wind, water, or ice. While sedimentation is a natural process, human activities such as construction can accelerate it, often leading to increased erosion and runoff that carries sediment into nearby waterways. The presence of excessive sediment is called sediment pollution and it can have devastating effects on aquatic ecosystems, drinking water quality, and wildlife habitats.
Fortunately, there are several ways to prevent sedimentation and prevent it from entering our waterways. Stormwater Best Management Practices (BMPs) and erosion and sediment controls can significantly reduce the amount of stormwater runoff and filter pollutants from entering nearby waterways.
Before delving into how to prevent sedimentation, it’s important to comprehend the severe environmental consequences that sediment pollution can cause.
Why Sediment Pollution is Such a Problem
The Environmental Protection Agency says that sediment pollution is responsible for nearly $16 billion in damage every year. When sediment enters storm drains and receiving waters, it can impair drinking water quality as well as the natural environment, affecting wildlife. Sediment that is carried by runoff and transported into storm drains can cause them to fill up and diminish their ability to convey stormwater, increasing the odds of flooding. The moment that sediment becomes loose, there is an increased potential for sediment pollution and damage.
Sediment in water prevents sunlight from penetrating the water and allowing the growth of natural vegetation. Water clouded by sediment also makes it more difficult for animals to see food and causes disruptions in the food chain resulting in a decline in the fish population and organism life.
Treating drinking water can take longer and be more expensive when sediment is present, and the treatment itself can leave water that smells and tastes bad.
Tiny silt and soil particles make sediment, but they can have an enormous impact ranging from clogging the gills of fish to making it next to impossible to be able to navigate rivers and streams, making it imperative to reduce the effects of sedimentation. But how is it that sediment pollution can be prevented?
How to Prevent Sediment Pollution
Storm Drain Filters
The right tools can prevent sediment pollution. One effective method of sediment pollution control is the use of stormwater management products and stormwater best management practices (BMPs). Storm drain filters such as drain guards, filter socks, gravel bags, and gutter guards serve as filtration devices for storm drains.
A storm drain filter that goes over the inlet can prevent sediment from getting into a storm drain, while a catch basin filter catches debris and sediment upon entry to a storm drain.
Perimeter Control Devices
Using a staked silt fence as well as a sediment barrier for perimeter sediment control will make certain that sediment that is moved either by man-made or natural forces will not leave a construction site and end up polluting waterways.
The staked silt fence and sediment barrier combination works extremely well for construction sites due to the fact that staked perimeter control measures will filter water while retaining silt and sediment. These sediment control devices, which also include the likes of ditch checks, silt dikes, and silt socks, are manufactured out of polypropylene geotextiles.
There are also other biodegradable erosion and sediment control devices used for supporting natural habitats by helping to reduce sediment pollution. Coir logs and straw wattles are two such examples of this, which help with controlling erosion while also offering silt filtration.
River bank erosion can also be effectively controlled by geotextile fabrics.
Infiltration Best Management Practices
Infiltration BMPs like swales, trenches, and infiltration basins are also valuable for preventing sedimentation during land development projects and on construction sites.
These BMPs serve a dual purpose.
First, they help to reduce the amount of sediment in stormwater runoff by slowing down its energy.
Next, they allow the runoff to infiltrate the ground and trap sediment in the basin’s permeable materials.
Together they’re an effective way to reduce sedimentation on construction sites and other areas where land development is taking place, helping to protect nearby waterways from the negative impacts of sediment pollution.
Vegetative Best Management Practices
Like infiltration BMPs, vegetative BMPs are also effective tools for filtering sediment from stormwater runoff before reaching nearby streams, lakes, and other waterways.
Vegetative BMPs like bioretention cells and vegetated swales are typically designed as shallow depressions or trenches filled with soil and vegetation that capture and treat stormwater as it flows through. As water flows through the soil and plants in the cell, sediment and other pollutants are filtered out and absorbed by the vegetation.
Constructed wetlands work similarly but are designed to mimic natural wetland ecosystems. Plants and bacteria native to wetlands work together to treat and filter sediment from the water before entering more extensive waterways.
During construction and land development projects, vegetative BMPs are relied upon as cost-effective and sustainable solutions to stormwater management.
Turbidity curtains are a last resort in the fight against sediment pollution. Sediment runoff should ideally have been stopped before it reaches the waterline with the use of perimeter control as well as other forms of onsite best management practices.
If their use has become unavoidable, turbidity curtains will help with quality and the prevention of sediment spread through waterways.
The disturbance of sediment on a site can result in the creation of thick clouds of dust. That rising dust can then move to other locations and settle there while also causing pollution in the air. Dust control methods are used for the prevention or mitigation of sediment particles in the air.
The area is sprayed with a fine mist by a dust suppression system that helps the dust to settle and prevent any more from rising.
Sediment pollution is a big problem for the health of animals, humans, and the environment, and the right tools and practices are required to stop it.