Bottom Ash
Bottom Ash
(OP)
I hope this is in the correct forum.
I am currently serving as the field engineer for a project where we are consolidating the bottom ash in the area onto the existing stockpile of bottom ash. Then we will be capping all of the waste material. Per the contract specifications, there is no density testing requirement, but only verification of compaction with a vibratory roller and lifts no thicker than 12 inches (loose). Then a proof roll inspection every 4 ft of compacted fill placed.
We've been having some problems with moisture levels so I was wondering if anyone has had any previous experience and could give some recommendations.
Our current plan forward is to start placing 6 inch lifts instead of 12 inch lifts. The thought being that this would allow for the material to dry out longer than the time it currently sits out.
Would simply allowing for the material to site & dry out longer be more helpful?
We have currently been placing the material at the top of the existing pile. Then spread out the material down the slope. Then the next day we would push the ash material where it needs to go.
I am currently serving as the field engineer for a project where we are consolidating the bottom ash in the area onto the existing stockpile of bottom ash. Then we will be capping all of the waste material. Per the contract specifications, there is no density testing requirement, but only verification of compaction with a vibratory roller and lifts no thicker than 12 inches (loose). Then a proof roll inspection every 4 ft of compacted fill placed.
We've been having some problems with moisture levels so I was wondering if anyone has had any previous experience and could give some recommendations.
Our current plan forward is to start placing 6 inch lifts instead of 12 inch lifts. The thought being that this would allow for the material to dry out longer than the time it currently sits out.
Would simply allowing for the material to site & dry out longer be more helpful?
We have currently been placing the material at the top of the existing pile. Then spread out the material down the slope. Then the next day we would push the ash material where it needs to go.
--morgwreck243





RE: Bottom Ash
RE: Bottom Ash
I agree about the spec not stating exactly what fails / passes. It just states that it will pass a Proof Roll inspection. The inspection is performed under the observation of the client's Engineer and a soil technician (our subcontractor).
--morgwreck243
RE: Bottom Ash
RE: Bottom Ash
RE: Bottom Ash
After the landfill is completed & the sodding is established the only equipment expected to be used on top of the cap are the lawn mowers and other maintenance trucks for the sod cover.
--morgwreck243
RE: Bottom Ash
RE: Bottom Ash
Warn them about it.
RE: Bottom Ash
www.SlideRuleEra.net
www.VacuumTubeEra.net
RE: Bottom Ash
SlideRuleEra - We have figured that we needed more time to let the ash material dry out; especially since it has been pulled out of the adjacent infiltration basin. Plus, we have been hit with a lot of rain recently.
As for the landfill,to the best of my knowledge the landfill is unlined underneath. Although, during our grading operations along the edge of the existing landfill we have run across a heavy cloth which seems to be put in, like a liner, but I am unsure if that was to just seperate the clean fill berms around the sides or if it extends all the way underneath the existing ash stockpile. So there maybe a liner, but nothing I would consider stopping the transport of heavy metals contaminants.
--morgwreck243
RE: Bottom Ash
Continuing to assume this ash comes from pulverized coal, as long as the bottom of the landfill is above groundwater and the top / sides are capped that would be ok... thought a liner might be required by regulators these days in light of several recent coal ash environmental incidents.
The cloth you encountered is probably a geotextile fabric - not a liner, and was used during the original construction of the "bottom ash pond".
The objective with closing an ash pond to cost effectively relocate the bottom ash to a landfill. If taking more time for draining the ash will solve the problem, that will likely be the way to go - drying time for a waste product is cheap. This is especially true if you are working with volumes of bottom ash measured in hundreds (or even thousands) of acre-feet.
www.SlideRuleEra.net
www.VacuumTubeEra.net
RE: Bottom Ash
I'll have to look into which method the coal ash was produced from, but based on the design it would seem like it is from pulverized coal. And yes the landfill is above the water table.
We are installing a cap (GCL, GDL liner) with a drainage system to prevent any runoff from entering the waste pile.
To everyone else thanks for the information.
--morgwreck243