Hi can anyone explain to me what is the 'special type of sand and gravel' they would be using in this project?
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'Submarine tomb'
- Thread starter pauljohn
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MikeHalloran
Mechanical
Beats the 'used food' outta me.
Mike Halloran
Pembroke Pines, FL, USA
Mike Halloran
Pembroke Pines, FL, USA
That's not Paul John as in "Jones" is it?
I don't know either, but perhaps it might only be more dense than typical sand.
BigInch![[worm]](/data/assets/smilies/worm.gif "[worm] [worm]")
-born in the trenches.
I don't know either, but perhaps it might only be more dense than typical sand.
BigInch
-born in the trenches.
GeoPaveTraffic
Geotechnical
I also don't have a clue what type of material they are talking about. But, it doesn't seam like any type of sand and gravel would prevent the mercury from leaching out into the sea. Looks to me like you would need a concrete or some type of waterproof layer in there.
Mercury is dense. Would it not tend to stay on the seabed and the sand and gravel cover is to stop fish getting at it and to prevent moving seawater from carrying it away?
Stephen Argles
Land & Marine
Stephen Argles
Land & Marine
I think if you can keep the currents away from the mercury, if any escapes it will pretty much tend to go down, rather than left, right, forward, back or up, so that's probably all they really want to make sure happens.
BigInch-born in the trenches.
BigInch
-born in the trenches.Placing of the sand will be the interesting bit as the mercury may get stirred up by the placing operation.
Stephen Argles
Land & Marine
Stephen Argles
Land & Marine
Makes sense if the 'special sand' includes some clay.
The gravel probably holds the cap in place.
The threat is mercury solubilizing into the seawater; believe it solubilizes as chloride. Wikipedia article says the oceans already contain an average 3×10-5 mg/L of mercury. Enough to make predator fish such as swordfish & tuna a bit toxic.
Re placing of the cap: Off the Palos Verdes peninsula (SW corner of Los Angeles County), the seabottom is contaminated with DDT. Several 3-acre test plots were capped in 2002 by dumping silt dredged from harbors. It gave a uniform 1.5 foot coverage at the 140-200 foot depths. The stuff fell relatively straight (little drift), with dispersion probably helping even it out. So, capping is possible.
The gravel probably holds the cap in place.
The threat is mercury solubilizing into the seawater; believe it solubilizes as chloride. Wikipedia article says the oceans already contain an average 3×10-5 mg/L of mercury. Enough to make predator fish such as swordfish & tuna a bit toxic.
Re placing of the cap: Off the Palos Verdes peninsula (SW corner of Los Angeles County), the seabottom is contaminated with DDT. Several 3-acre test plots were capped in 2002 by dumping silt dredged from harbors. It gave a uniform 1.5 foot coverage at the 140-200 foot depths. The stuff fell relatively straight (little drift), with dispersion probably helping even it out. So, capping is possible.
Probably the mercury is still contained within the original, but maybe deteriorating flasks, if not hopefully still within closed sub bulkheads.
BigInch-born in the trenches.
BigInch
-born in the trenches.- Thread starter
- #10
I don't mind. When they try to report the technical details, they still get it basackwards.
BigInch-born in the trenches.
BigInch
-born in the trenches.- Status