Current standard for lead in private home drinking water
My understanding is that the LCR from the EPA establishes 15 ppb as the actionable level for public drinking water. I cannot find any similar standard for drinking water in the home from a private well. I know that the best lead is no lead. Is there an "actionable level" for a private residence? Thanks. Chris
Carroll County Maryland
Thanks for these great and important questions. First, I wanted to point out that, since well water is not regulated, there are no specific drinking water standards for private drinking water. So you should use the EPA drinking water standards as a guideline.
In the case of lead, however, the standards get a little confusing. As you said, you want no lead in your water, and the EPA agrees. They set the Maximum Contaminant Level (MCL) for lead as zero. Lead is extremely detrimental to child development, so you do not want to expose children to lead at all.
However, because lead is not in the water, but enters the water through corroding pipes, the EPA also set an Action Level for PUBLIC utilities. They obviously can't monitor the water coming out of everyone's tap, so based on the Lead and Copper Rule, public utilities must test lead (and copper) in drinking water that is taken from their customers' taps. If 10% or more of those customers' samples have lead exceeding 15ppb, then the utility must "undertake actions to control corrosion".
This action level does not apply to a private well owner because the only system you have to manage is your own. So you want to focus on the MCL, which is zero - and not the Action Level. If you have any amount of lead in your drinking water, then its critical that you do something immediately to protect your and your family's health.
I suggest checking out Virginia Tech's factsheet about heavy metals in drinking water: https://www.wellwater.bse.vt.edu/files/HeavyMetals442-657_pdf.PDF. And if you have any other questions, please feel free to email me directly, email@example.com.