Lead In Drinking Water

Part of the Water Wisdom Series for Home Inspectors by: Scott J. Bradley

Home Inspectors & Lead
Where does it come from and what levels are dangerous?
What does it mean to have lead in our drinking water?
The U.S. Environmental Protection Agency (EPA) sets the Maximum Contaminant Level (MCL) for Lead in Drinking Water at 0.015 mg/L. (zero point zero one five milligrams per liter, or fifteen parts per billion).
Lead can come from the source, distribution to the home, or from within the home or building.
Lead poisoning is more serious for children as it can severely hinder mental development.

Home Inspectors Testing for Lead in Drinking Water
There are two main types of samples taken for lead testing in a home or building: First Draw & Flush Lead .
First Draw samples are one liter samples taken after the water has not been run for at least six, but not more than twelve hours prior to sampling. Home Inspectors should take these type of lead sample to measure the lead contribution, if any, coming from the home.
Flush samples are taken after the cold water has run for at least fifteen minutes, or until the temperature has stabilized. This determines lead from the source.

Home Inspectors and Corrosion Control!
Lead can leach out of the solder in copper pipe fittings if the water is corrosive because of low pH (acidic drinking water) and possibly low alkalinity as well.
Outlawed for a number of years, many buildings including schools and homes still have lead solder in their pipe fittings.
Scaling – the deposition of Calcium Carbonate (CaCO3) on the inside of pipes will protect against lead (if present) from being corroded from the fittings.
If the source water is low in CaCO3, then the pipes can be lined chemically with polyphosphate.
Scaling is the natural formation of CaCO3 on the inside of pipes, and may be induced by changing pH in some cases.

Home Inspectors and Mitigation: Let’s Get the Lead Out!
Lead in drinking water can be filtered out, but it is better to remove the source if possible. Some lead may come through municipal lines and still be under the MCL, so some folks may want to filter that out. Lead can come from lead entry pipes, or some fixtures with alloy fittings as well.
To get unbiased information on
drinking water filters, I go to the
National Sanitation Foundation…

Home Inspectors Shipping Drinking Water Lead Samples to the Lab.
Most labs will supply you with the correct container. Good quality plastic like HDPE (high density polyethylene) is a good choice.
Collect what the labs says for volume, depending on flush or first draw sample. (see slide # 3)
Lead samples are preserved
with nitric acid (HNO3) to
a pH of less than 2.

Home Inspectors Sampling Guide for Drinking Water
If you want a visual guideline and demonstrations of taking a number of different drinking water samples including VOC, and SOC samples, go to the address below, and click on the video sampling button…
http://www.aquacheck-vt.com/
It will open a flash video that will play on high speed or dial up connections just fine. And no, those aren’t my hands in the video! : - )

Analyzing Lead in Drinking Water
There are two main methods for analyzing lead in drinking water. The methods have to be able to accurately detect lead down to less than fifteen parts per billion (ppb), and practically at one to two ppb.
Atomic Absorption Graphite Furnace Platform works very well and is Standard Method SM3113B. (the method I use).
Inductively Coupled Plasma Mass spectrometers
can detect even lower levels in the
parts per trillion range
Be sure the lab you use is
certified to test for lead
in drinking water.
Picture Courtesy HP

Home Inspectors and Lead
Now you know…
Where lead comes from in our drinking water.
Why we want to remove it from our drinking water.
Where to go to find treatment information
How to take a proper sample for lead in drinking water and preserve it if necessary.
Reference to a site with a video demonstrating proper drinking water sampling techniques.
Approved Methods for analyzing Lead.

Home Inspectors Series: Lead
I hope you enjoyed this issue of Water Wisdom for Home Inspectors, brought to you as a courtesy learning tool from Scott J. Bradley at Aquacheck Laboratory, Inc.
http://www.aquacheck-vt.com
1-800-263-9596

Lead In Drinking Water

by Scott Bradley

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Lead In Drinking Water Presentation Transcript