Wastewater basin remediation options.

[jjv2006]

I would like your thoughts on this following scenario.
We have a wastewater basin that has minor contamination of PCBs, metals and the like. The local DEP would like us to remediate and close this basin. Filling in the whole basin with debris is an option but might require a lot earth work based on the size of the basin (12 acres). Stabilization is effective but costly.

Any other applicable methods which might be cost effective and simple to implement. It is not required that this area will be re-used in the future.


Thanks.

 

[greenone]

How far down is the water table? Will they allow the area to be capped with an impervious surface, or is the DEP requiring removal of the PCBs? How deep do you need to go?
Can you provide some more detail?

 

[jjv2006]

The water table is at 15 below ground surface. And the extent of sludge is at almost 10 feet. Capping with impervious surface is not allowed by DEP. DEP is not requiring removal of PCBs but does not want any leaching in adjoining areas and within the area.


Hope this information helps.

 

[bimr]

Have you considered soil remediation. Don't see why you cannot incinerate the soils to remove the PCB and then put the soils back in place. Maybe this would be too expensive.

 

[greenone]

Ok, so DEP is not requiring PCB removal, but won't let you cap, and doesn't want the PCBs to leach. Kinda sounds like a back door way to make you remove the PCBS.
There are onsite thermal units so you can remove it, clean it, and put it back in place. Other wise, you're hauling almost 250,000 cy out.
How about driving sheeting all around the area with a filter fabric so it is contained laterally?

 

[DMcGrath]

You mention that filling in the basin with debris is an option - how about coal ash (CCB)? Depending on your state rules, it may be an affordable source of fill. Here in Virginia, about the only restriction is a separation of 2-3 feet from groundwater. It is pretty structurally stable by itself, or it can be amended with lime to make it more concrete-like.

 

[oxilume]

jjv2006,

Submerged Plasma Oxidation may be a simple and cost effective solution.
see:

http://www.plasmawhirl.com

Todd

http://www.oxilume.com

 

[kenvlach]

The US EPA Technology Innovation Program has a huge amount of info on Remediation:

http://clu-in.org/remed1.cfm

Look under the headings
Remediation (includes Technologies),
Databases &
Publications.