Getting the lead out — at the faucet

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Courtesy of Industrial Test Systems, Inc.

You might be surprised at where you’ll find a customer’s lead.

Lead is making headlines.

First, we should note that the current attention is not due to water, air or soil contamination, but from lead contamination recently found in toys and children’s jewelry made in China. This is very frightening for any parent because of the harm lead can to cause in children. How could this happen? How concerned should you and your customers be about lead?

In view of this heightened awareness, I recently tested the lead levels in water coming out of faucets. In addition, I tested for the presence of lead in the solid particulate material (particles) that may be trapped in the faucet aerator filter and the lead level contained in the metal filter holder or nozzle. The interesting results are shown on the accompanying table (sidebar).

The testing was done using Industrial Test Systems, Inc. LEADQuick™ (part no. 488375) test kit and Hach’s LeadTrak™ Pocket Colorimeter II™ (part no. 5953021).

How it was done
The “Lead found in water” data (first results column in table) was collected using the water testing procedure as outlined in the LEADQuick™ instruction manual. The test procedures used to collect the “Lead particles in aerator filter” and the “Lead found in nozzle” data (second and third results columns in table) are described below.

To test for lead in particles in the aerator filter, I followed these steps:

The threaded aerator nozzle was carefully removed from the faucet, and the solid material collected from the filter screen was transferred into a 50-milliliter (ml) beaker. (To avoid lead contamination during the transfer, only plastic utensils were used).

Three drops of LEADQuick™ Pb-1 acid solution were added to the particles. The particles were then allowed to sit for five minutes.

10 ml of deionized water was then added to the beaker and the liquid was decanted to a sample cell for testing. To test for lead particles in the nozzle:

The nozzle was placed into a clean 50-ml beaker. Three drops of LEADQuick™ Pb-1 acid solution were added directly to the nozzle and then the nozzle was allowed to sit for five minutes.

10 ml of lead-free water was then added to the beaker and the liquid was decanted to a sample cell for testing. Once the particles and nozzle were prepared for analysis the testing was continued as described below.

The analysis
The first step in the analyses of the water, the collected particles, and the nozzle was to acidify the sample by the addition of the three drops of the Pb-1 acid reagent (as described above). A waiting period allows the acid to solubilize the lead.

Pb-2 buffer (10 drops) is then added to make the solution alkali.

Next, eXact™ strip Pb-3 is dipped for 20 seconds with gentle motion, this adds the porphyrin indicator and mixes the solution. After a one-minute wait, which allows the porphyrin and the solubilized lead to form a colorimetric complex, the LeadTrak™ meter is turned on in the absorbance mode (“abs”) and is zeroed with the sample cell in the meter.

Without disturbing or moving the sample cell from the meter measuring window, the eXact™ Strip Pb-4 is dipped into the sample for 20 seconds with gentle motion. This motion mixes and releases EDTA into the sample, and allows the EDTA to break up the colorimetric prophyrin-Pb+2 complex. After a one-minute wait, you read the “abs.”

The “abs” reading is compared to the conversion chart to determine the lead concentration as micrograms per liter (µg/L, or parts per billion [ppb]). The more negative the “abs” reading the higher the lead concentration in the sample.

Lead in only one water sample, but …
So what do the test data show?

From the table it can be readily seen that only one water sample from the nine tested was found to have lead (59 ppb). After a one-minute flush of this positive faucet, the faucet had a lead level of less than 3 ppb (< 3 ppb). Note that lead levels above 15 ppb exceed the allowed US Environmental Protection Agency (EPA) maximum.

Flushing works to get the lead out. Another alternative is to do as the owner of the faucet (my associate) does: He uses a pitcher carbon filter after the water is drawn from the tap.

Of the nine particle or sediment samples that were tested in the aerator filters, only two were found to be lead-free.

The significant source of Pb
This finding correlates with what other research studies* have found: Solid sediment particles that are either trapped on the water aerator screen or are in the potable water may be contributing sources of the lead found in tap water. This drives home the importance of point-of-use (POU) filtering devices on our faucets.

All nozzles tested positive for lead. Only the control faucet was free of any lead — and this nozzle was clearly labeled “Meets California Prop 65 and NSF/ANSI 61 lead-free standards.” Note that the US-allowed level for lead content in pipes in fixtures is up to 8 percent (or 80,000 ppm) lead.

If you are looking for lead around you, think about faucets first. Finding lead there might be very easy.

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