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"Within half a mile" is an inane standard. There's no evidence that a _buried_ cable leaches lead that far, that's simply bonkers. Lead is definitely not someth

"Within half a mile" is an inane standard. There's no evidence that a _buried_ cable leaches lead that far, that's simply bonkers. Lead is definitely not something to chew on, but this is histrionic fearbait reporting.

sclarisse 3y ago
Note that the half-mile statistic is connected to underwater cables, not buried cables. It is certainly an overcount, but it is probably not trivial to assess the local hydrology and the extent to which children’s play areas might be exposed to such water.
- reaperducer 3y ago
  it is probably not trivial to assess the local hydrology and the extent to which children’s play areas might be exposed to such water. Especially since there are thousands and thousands of schools in America that get their water from wells. It doesn't seem overly-cautious to wonder about lead placed under a water course 50 years to a century ago finding its way into the groundwater supply a half-mile away.
  - prewett 3y ago
    Hopefully that wondering would lead to testing the water to see whether there is actually a problem.
  - gruez 3y ago
    >It doesn't seem overly-cautious to wonder about lead placed under a water course 50 years to a century ago finding its way into the groundwater supply a half-mile away. At that point wouldn't it be so diluted that it's basically indistinguishable from background levels?
mschuster91 3y ago
> There's no evidence that a _buried_ cable leaches lead that far Well, the question is how much lead leaches out and gets transported by rainfall down to groundwater tables from which we source our drinking water.
- derefr 3y ago
  I understand how lead-lined Roman aqueducts would put lead into drinking water — there's nowhere for the lead to go but to stay in the water, since the lead lining is below the water. But I'm unclear on how lead that had leached into groundwater would remain in groundwater. Shouldn't the lead, being heavier than water, drop out of the groundwater and get caught up in the soil? Isn't this the primary filtering function we expect of soil — the reason aggregate is used as a filtering medium in wastewater treatment? If not, wouldn't you expect to hear about water tables that have problematically-high natural levels of this or that heavy metal? Wouldn't you expect that it'd be deadly to drink groundwater that had ever flowed through any underground ore deposits?
  - whatshisface 3y ago
    Virtually everything that dissolves in water is heavier than an H2O molecule, and a lot (most?) soluble salts are denser than water. If you want an example, table salt sinks to the bottom before dissolving. Also, yes, some ground waters are naturally high in different metals. Before drinking water from a well you drilled you usually have to get the well's water tested.
    - derefr 3y ago
      My assumption in writing the above was that non-soluble elemental lead metal (the thing the sheathing is made out of, and that Roman aqueducts were made out of, and the thing that soil could easily trap and filter out) is the "problem" with lead poisoning; while the lead ions in lead compounds are mostly safe. Like it is with mercury, where mercury amalgams are perfectly fine to use as dental fillings, but getting even a little metallic mercury past your skin will kill you. Looking into it, though, apparently lead metal and lead ions are both toxic, through independent mechanisms. And that the toxicity of e.g. lead-based paint is due to the toxicity of lead compounds, rather than the toxicity of metallic lead. Still: is there cause to believe that metallic lead from lead sheathing in cables, would react with something in the ground to form soluble lead compounds, rather than remaining particulate metal and therefore coming to rest in the soil? Things don't oxidize underground, right? And groundwater is usually pH-neutral enough to not create an environment amenable for reduction reactions involving e.g. chromium or sulfur, right? I say this because several people above have mentioned that there are other metallic-ion "natural pollutants" in groundwater — but I've still never heard of groundwater with high natural lead levels.

sclarisse 3y ago

Note that the half-mile statistic is connected to underwater cables, not buried cables. It is certainly an overcount, but it is probably not trivial to assess the local hydrology and the extent to which children’s play areas might be exposed to such water.

reaperducer 3y ago
it is probably not trivial to assess the local hydrology and the extent to which children’s play areas might be exposed to such water. Especially since there are thousands and thousands of schools in America that get their water from wells. It doesn't seem overly-cautious to wonder about lead placed under a water course 50 years to a century ago finding its way into the groundwater supply a half-mile away.
- prewett 3y ago
  Hopefully that wondering would lead to testing the water to see whether there is actually a problem.
- gruez 3y ago
  >It doesn't seem overly-cautious to wonder about lead placed under a water course 50 years to a century ago finding its way into the groundwater supply a half-mile away. At that point wouldn't it be so diluted that it's basically indistinguishable from background levels?

mschuster91 3y ago

> There's no evidence that a _buried_ cable leaches lead that far Well, the question is how much lead leaches out and gets transported by rainfall down to groundwater tables from which we source our drinking water.

derefr 3y ago
I understand how lead-lined Roman aqueducts would put lead into drinking water — there's nowhere for the lead to go but to stay in the water, since the lead lining is below the water. But I'm unclear on how lead that had leached into groundwater would remain in groundwater. Shouldn't the lead, being heavier than water, drop out of the groundwater and get caught up in the soil? Isn't this the primary filtering function we expect of soil — the reason aggregate is used as a filtering medium in wastewater treatment? If not, wouldn't you expect to hear about water tables that have problematically-high natural levels of this or that heavy metal? Wouldn't you expect that it'd be deadly to drink groundwater that had ever flowed through any underground ore deposits?
- whatshisface 3y ago
  Virtually everything that dissolves in water is heavier than an H2O molecule, and a lot (most?) soluble salts are denser than water. If you want an example, table salt sinks to the bottom before dissolving. Also, yes, some ground waters are naturally high in different metals. Before drinking water from a well you drilled you usually have to get the well's water tested.
  - derefr 3y ago
    My assumption in writing the above was that non-soluble elemental lead metal (the thing the sheathing is made out of, and that Roman aqueducts were made out of, and the thing that soil could easily trap and filter out) is the "problem" with lead poisoning; while the lead ions in lead compounds are mostly safe. Like it is with mercury, where mercury amalgams are perfectly fine to use as dental fillings, but getting even a little metallic mercury past your skin will kill you. Looking into it, though, apparently lead metal and lead ions are both toxic, through independent mechanisms. And that the toxicity of e.g. lead-based paint is due to the toxicity of lead compounds, rather than the toxicity of metallic lead. Still: is there cause to believe that metallic lead from lead sheathing in cables, would react with something in the ground to form soluble lead compounds, rather than remaining particulate metal and therefore coming to rest in the soil? Things don't oxidize underground, right? And groundwater is usually pH-neutral enough to not create an environment amenable for reduction reactions involving e.g. chromium or sulfur, right? I say this because several people above have mentioned that there are other metallic-ion "natural pollutants" in groundwater — but I've still never heard of groundwater with high natural lead levels.