Sites where dams or ponds have been located present challenges. Normally our task is to return these sites to a non-erosive state with native vegetation that matches the pre-existing drainage patterns.
So the first charge is to deal with the remains of whatever was contained in the reservoir.
A thorough site assessment reveals the history of the site and how it was used.
Any residual water is sampled and analyzed along with sediments found in the bottoms. Earthen walls and – if practical – floors are tested for contaminants too.
Then the surrounding native soils are sampled and tested to get a picture of the natural condition of the site before excavation. The walls of the pond or dam are sampled too. Then a correlation with the native soil material is made to understand the construction and placement of native soil material.
A remediation plan is developed taking into account all of the findings of the site assessment and other regulatory,legal or contractual issues. The technical solution can vary greatly in complexity based upon the combination of these factors. [See case histories]
The first and perhaps most difficult part is deciding what to do with that found inside the reservoir cavity. These are sometimes lined and sometimes not. The residual water is often saline and can harbor other undesirable constituents.
We can sometimes capture a portion the water for beneficial use with our portable treatment systems. We also have the ability concentrate the water down to its constituent salts or haul it to an acceptable repository.
The sediments are often composed of soil that is blown-in or eroded from the walls, decayed pond vegetation and coal fines. These can be saline especially if the bottom has dried out. Otherwise much of the salt is removed with the water.
Often these are benign and can be buried. However if we find certain contaminants the sediments must be treated separately and / or hauled to an appropriate repository.
Plastic liners are best recycled but they must be clean. Often they are disposed of at a landfill.
Once the contents of the reservoir are dealt with, the site reconstruction begins according to the site remediation plan. Our team strives to create a desirable soil profile from the available materials. In-field testing occurs throughout the earthworks phase and topographic surveying ensures that the drainage patterns are according to design.