Hey! My last week with @SeaGrant is here. #SedimentSam will be sticking around, but we have one last joint message to share w/the #GreatLakes.

Someday modern science may give us a pollution blaster laser gun thingy that makes contaminated #sediment disappear. Until then...

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We have to address the problem: historic pollutants. Sediment acts as a storehouse for this contamination. A variety of wildlife, fishes, and invertebrates cannot thrive, reproduce successfully, or even survive if they interact with contaminated sediment in their habitat.

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Sediment-dwelling organisms bear the brunt of this impact. Some contaminants can move up the food chain and leave fish and wildlife unsafe to eat. They make the water unsuitable for swimming and prevent communities from performing routine dredging.

IMG design @ILINSeaGrant

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Modern science does not give us the ability to make the contamination go away (for now, no laser blaster). We are working in large natural systems with multiple contaminants. Rather than dwell on a problem that modern science will not allow us to fix - that contaminants exist

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- we focus on the problems that we can solve: contaminants are interacting with aquatic life, and contaminants are restricting human activities. Our remedy must cut off the connection between sediment contamination and the ecosystem.

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We want our remedy to work with the natural environment, not against it. Contaminants for the most part are really attracted to sediment. This is a strong bond at the chemical level. We choose a remedy that protects the natural sediment-contaminant bond.

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Whether we remove the sediment and place it in containment, or we leave it in place and cap it, the remedy must isolate the contaminated sediment from the rest of the environment in the long-term.

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In designing effective containment, we protect the sediment-contaminant bond. ​​Containment needs to create a physical barrier between the contaminated sediment and the ecosystem. & it needs to create a 360 surrounding. This may require the addition of a cover/liner/berm.

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There can be space restrictions (like putting a cap under a navigation channel) or very high toxin concentrations, making a physical barrier inadequate. In such cases, a chemical barrier can be added.

Erosive conditions (extreme weather, wave action) may warrant + armoring.

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Some communities have future plans for the site requiring adjustments. E.g., water depth may need to accommodate large boats or a CDF/landfill slope may need to be flat for future recreation.

Local, state, and federal law may create a need for inspections or monitoring.

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There is a lot of stuff to consider! It takes time, but it pays off to make sure the appropriate protective features are included to contain sediment in the long-term.

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Sediment containment is designed in AOCs by sediment scientists, engineers, cost-share partners, communities, and more in #GreatLakesLegacyAct projects (sediment cleanups funded by #GLRI)

Learn more at http://www.greatlakesmud.org !

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You can follow @Gr8LakesLady.
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