Why Add Polymers?

One of the biggest challenges on a dredging project is managing the water that is excavated and transported with the sediment. On hydraulic dredging jobs where sediment and water are pumped through a pipeline as a slurry, water can account for 90+ percent of the volumetric flow. After the slurry reaches the disposal area, the water must be separated from the sediment, collected, and often clarified or treated. This process must happen as fast as the water is being pumped, which for a 12-inch cutterhead dredge could be 5,000 gallons per minute.

Our experience in wetland habitat restoration began decades ago with the Upper Mississippi River Restoration Program (UMRR), the largest restoration program ever undertaken on a major waterway worldwide.  Since then, restoring marshes, wetlands, and highly sensitive ecosystems along inland and coastal waters nationwide has been a main initiative.

Capping is an integral part of the remediation of a water body. As the benthic community generally lives on the bottom of a lake or river, these micro-organisms are a key piece of the ecological food chain. They are also very sensitive to contaminants, and any level of exposure can greatly reduce their population. Putting a cover, or cap, of clean material such as sand, engineered materials, or stone over the bottom of the waterway can provide the clean environment in which the benthic community can flourish while trace amounts of contaminants are left to safely decompose underneath.