Dredging

One of the two long-term solutions we have recommended to the Waterford Neighborhood is dredging the pond. This solution would return the pond to its original depth which would alleviate much of the algae and aquatic vegetation issues.

To estimate the amount of sediment that would need to be dredged, our site survey data was used alongside ArcMap to get a volumetric estimate. The current average depth of the pond was found to be just over 2 ft. A member of the Homeowner's Association told us the original depth was around 7-10 feet, so we estimated we would want to dredge out a 5ft. depth averaged across the entire surface area of the pond.

Dredged Volume = 5 ft * 1.085 ac = 1.085 ac-ft = 8,753 yd^3

To estimate the costs of dredging we contacted 3 local contractors. H&A Resource Management told us they would go visit and investigate the pond then get back to us with their estimate. They have never gotten back to us.

We called and left voicemails with RESPEC and Heartland Dredging, we never heard back from these companies either.

So, from www.dredgingspecialists.com we obtained very general numbers to calculate a ballpark estimate cost of dredging the pond. Based on the rate per cubic yard of dredged material and price of mobilization and demobilization the price range for dredging would be $55,000 - $120,000.

We were also advised it would be wise to take samples from the bed material of the pond and test them for heavy metals to ensure there would be no special requirements necessary for removing the material during dredging, or issues with keeping the material on-site for a stream restoration project.

We took 2 core samples, one from the inlet side of the pond, and another near the outlet weir, homogenized and dried the sediment, then took the samples to UK's Regulatory Services and had them analyzed for heavy metal concentrations. The results as well as the EPA guidelines for heavy metals in sediment are below.