I have three neighborhood stormwater retention ponds that are about 20 years old. One had accumulated so much sediment in spots that sandbars were developing (in front of culverts), but the pond had accumulated about 5 feet of sludge in general. It was quite expensive to excavate.

The other two ponds do not have sandbars or as many culverts, but they still have an estimated 3-4 feet of muck. They're also larger than the first pond.

Is it possible to actually eat away the muck with a combination of aeration and bacteria? I'd be interested to know anyone's experiences with that. We're investigating less costly solutions to improve water depth and extend the lives of our ponds without excavation.