Disposal of trickling filter rocks

[aussiemike]

I am currently managing a project that involves the decommissioning and demolition of an old rock media trickling filter sewage treatment plant. (The flow from the plant is soon to be diverted to a shiny new BNR plant across the river. Ooops, looks like they missed the entire activated sludge era!)

The plant has five "fly magnets", containing a total of about 10,000 cubic metres of rocks. About half the rocks are smooth river rocks, while the other half look a bit like the ballast you see on railway tracks.

I will soon organise a meeting with the EPA to get their thoughts (if any) but I'd like to toss up a question for the forum first...

WHAT THE HELL do we do with all those rocks?

Reuse them somewhere? Sell them as something useful? Crush them up for road base? Cover them up and hope they will disappear?

Fortunately, we will have some nice big holes on site we can bulldoze them into, but how should we clean them? Should we flood the filters and superchlorinate them? Clean them with a water blaster? Not bother cleaning them at all?

Any advice from those who have trodden this (presumably) well worn path would be greatly appreciated.

Cheers,
Aussie Mike

 

[BobPE]

Mike:

You have to treat them as bio hazzards. Putting them on site is not a good idea nor is reuse that will put people in contact with them. I have placed them in sanitary landfills here in the states, landfills that accept sludge will usually use the media as cover.

BobPE