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As far as I can tell only the last link has any quantitative information about the actual level of contamination: Lead: Of the 66 sampling locations, 35 of the

As far as I can tell only the last link has any quantitative information about the actual level of contamination: Lead: Of the 66 sampling locations, 35 of the first samples exceeded EPA’s 15 ppb Lead Action Level. Results for Lead ranged between 16 ppb and 20,000 ppb. For the second samples, after flushing the water for 3-5 minutes, the levels fell to below the Lead Action level for all but two sample locations. Copper: Of the 66 sampling locations, 15 of the first samples exceeded EPA’s 1300 ppb Copper Action Level. Results for Copper ranged between 1320 and 137,000 ppb. For the second samples, after flushing the water for 3-5 minutes, the levels fell to below the Copper Action level for all locations. Note: 20,000 ppb is 20 mg/L, which is ... yeah that's a pretty high dose of lead.

londons_explore 3y ago
'flushing for 3-5 minutes ' solving the issue shows that it is likely in the pipes of the household that tests are being done in. Aka, someone still has lead pipes in their house. Could maybe be lead pipes leading to the house from the street too. There are two fixes: * add phosphates to the water, which reduce the amount of lead that will dissolve. Done in old cities where a large proportion of people still have lead pipes. * go replace those pipes. Done where only a small chunk of people have lead pipes so it is feasible to replace them all.
guenthert 3y ago
> Note: 20,000 ppb is 20 mg/L, which is ... yeah that's a pretty high dose of lead. It's 20μg/L. It's bad (hence the state of emergency), but not so bad that you would actually see the lead with naked eyes.
- xyzzy123 3y ago
  I did a double take also, the unit conversion is a bit confusing... 1 ppb is 1 nanogram per gram but there are 1000 grams in a litre so 1 ppb is actually 1 microgram per litre. So I still think that approx 20mg/L is the correct figure.
  - guenthert 3y ago
    Ouch, yes and I even had my coffee already.

londons_explore 3y ago

'flushing for 3-5 minutes ' solving the issue shows that it is likely in the pipes of the household that tests are being done in. Aka, someone still has lead pipes in their house. Could maybe be lead pipes leading to the house from the street too. There are two fixes: * add phosphates to the water, which reduce the amount of lead that will dissolve. Done in old cities where a large proportion of people still have lead pipes. * go replace those pipes. Done where only a small chunk of people have lead pipes so it is feasible to replace them all.

guenthert 3y ago

> Note: 20,000 ppb is 20 mg/L, which is ... yeah that's a pretty high dose of lead. It's 20μg/L. It's bad (hence the state of emergency), but not so bad that you would actually see the lead with naked eyes.

xyzzy123 3y ago
I did a double take also, the unit conversion is a bit confusing... 1 ppb is 1 nanogram per gram but there are 1000 grams in a litre so 1 ppb is actually 1 microgram per litre. So I still think that approx 20mg/L is the correct figure.
- guenthert 3y ago
  Ouch, yes and I even had my coffee already.