What Are Contaminated Sediments?
Sediments are soil and other mineral particles that settle to the bottom of a body of water. This might seem fairly innocuous, but scientists are starting to think that they may pose an environmental threat. The reason for this is that other compounds and pollutants could attach to the sediments and sink to the bottom with them, thus polluting the body of water and potentially being hazardous to the life living in it.
How Widespread is the Problem?
According to the EPA, sediments are one of the biggest threats that the US environment faces today. The problem is fairly widespread because before we knew how bad the problem with sediments was, water was freely dumped into bodies of water without being sufficiently treated and removed of pollutants.
Shockingly, one in ten bodies of water in the US contain toxic chemicals, according to the EPA! The impact of this is often death, and it can make humans who consume the contaminated water very ill. Animals are indirectly affected, as they will eat several contaminated fish and will ingest large amounts of the toxic chemicals. If humans were to consume these fish (or eat animals who ate the fish) this could lead to toxic food being ingested by humans, which is a significant health risk.
The economic impact of this can also be felt by fishermen. If they cannot fish in waters that they have fished in for their whole lives, it will mean that they may have to change professions or move. Or, they will simply have to catch fewer fish and look in different areas. Either way, it is clear that this will have an increasingly negative impact on the livelihood of many fisherman in the United States, particularly those dealing with fresh water fish.
How Does Contamination Occur?
Air pollution can be a large factor in leading to pollution, according to the EPA. Mercury is a very common pollutant which is airborne. In addition, they can be contaminated directly by run off waste from farms, cities and factories (among other industrial activity), all of which often contain toxic pollutants which run straight into bodies of water.
Then, these pollutants will stick to sedimentary particles, then the sedimentary particles sink to the bottom of the body of water, meaning that the entire lake, river, etc will begin to be contaminated with the polluting chemical. All fish will then take in the water, and the toxic chemicals will be transferred through the food chain.
How Can the Problem Be Solved?
Sediment removal, despite being expensive, is one of the solutions. It is removed and placed in a special sediment removal part of a landfill by one method. Additionally, microorganisms that can consume the toxic chemicals are used to try to clean up the site and make it more hospitable.
Alternative and less costly measures can be taken, such as site management. This involves managing the flow of water and directing fish away from known contaminated water sources. While this will not solve the problem, it could be an effective short term way to remedy it.