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Photograph of a dripping water faucet at a sink where we tested the water for lead (C) Daniel Friedman How to Test for Lead Contamination in Water

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Water tests for lead contamination:

What drinking water contamination tests should you order? This article explains the general classes of water contaminants covered in a water test for lead.



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There are several possible sources of lead in drinking water, including lead in ground water, lead contamination from municipal water piping, lead contamination from building water supply piping or fixtures, well contamination by lead from surface contamination due to lead paint chips, and insignificant lead contamination from lead in well pumps or faucet parts.

This website describes the types of water testing available, outlines common water test fees, describes the details of what parameters are included in various water test options, and gives advice to assist you in deciding what tests to order.

Lead Contamination from Water Supply Lines/Entry Mains, Lead Testing & Correcting Contamination from - Lead Pipe Problems/Advice

Depending on the duration and extent of lead-water contact, lead can enter the water supply if lead is present in supply piping or fixtures. Common sources of lead in water supply piping include older lead-bearing solder used on copper pipes, possible lead content in brass piping or fixtures, lead water supply piping (rare), and lead water supply entry main between a building and the public water main in the street (common in some areas).

Health hazards from lead content in water

Recently there was also a flurry of concern about lead contributed by brass in private well pumps. However the testing methods used for this latter topic misrepresented an exaggerated and frankly dubious risk. Finally, it is possible for lead to be found in private well water if lead contaminants have entered the local aquifer.

Action Level for Lead in Water - allowable lead limits

New York State Department of Health has set an action level of 0.015 mg/L of lead in a sample of water drawn from a tap used for drinking water after a 6-hour period of no water use.

Variations in Lead Level vs. Testing Methods

Lead levels will usually be quite high in water which has sat overnight in a lead line from street main to house.

Most lab tests indicate low lead levels in water from such lines after the test fixture has run until all standing water in the piping has been flushed out with fresh from the municipal supply mains in the street.

There are ambiguities in instructions offered by some municipalities about how to obtain a water sample for lead testing. The particulars of how the water sample is taken can make a big difference in the lead level obtained.

Our photo (below) shows how to recognize lead water supply piping between a building water shutoff valve (or water meter) and the water supply mains in the street. The author is pointing to the wide lead wipe joint connecting the lead water pipe to the bronze bottom of the water shutoff valve.

Photograph of a lead water pipe providing water service to a home in New York (C) Daniel Friedman

  1. The very first draw of lead test water from a faucet or plumbing fixture is measuring lead contributed by any lead-containing brass which is present in some faucets.
  2. "First draw" taken after a moment of flushing out the faucet to test for lead is taking water from the pipes near the fixture. Depending on pipe material and length, considerably more water might have to be taken before observing the water sample exposed to most lead uptake.
  3. First cold water after a night of no usage when testing for lead is likely to provide water that was sitting in the entry main from street to house. If this line is lead, the lead content of this sample will be quite high. Alternatively, if all piping were visible between the test fixture and water meter (rarely the case) one could calculate the volume of water necessary to flush to obtain a sample from the line to the street.
  4. A water sample taken after running the water for several minutes when performing a lead in water test  (depending on length of piping in the house from street to fixture) is sampling the quality of water provided by the municipality. Some city plumbing officials have expressed the opinion that lead oxide build-up in pipes insulates against significant lead levels in water actively running through such lines.

Most local building codes do not require removal of lead, for example, the City of Poughkeepsie Building Codes do not require removal of residential lead supply lines (house to street). However eventually (usually after 40-60 years) these lines corrode, leak, and have to be replaced. Replacing the main supply from street to the water meter, when required, could involve significant expense.

People with concerns for the amount of lead in water should consult the local health department and should have their water tested for lead. Typical lab fees are $20. to $25. per sample plus the cost of hiring an independent consultant to collect and handle the water sample if you don't do it yourself.

Even if you are not concerned with testing for lead in water it would be wise to reduce possible lead intake by flushing any lead-containing piping before drinking such water. In addition, lead-in-water removal equipment is available from water treatment companies.

If you need to calculate the amount of water to run out of piping to be sure you are obtaining water from the street, that is, the volume of gallons of water inside of water piping, you need to know simply the length and diameter of water piping between the faucet where the water test is to be taken and the location whose water you want to test.

For example, let's say the water contained overnight in the water main in your street is what we want to test.

1/2" internal diameter water piping contains about 0.01 gallons per linear foot;

3/4" ID piping contains about 0.02 gallons per linear foot, and

1" water piping contains about 0.04 gallons per linear foot.

Just measure or estimate the number of linear feet of water piping of each diameter to perform this calculation.

Alternative worst-case lead in water test procedure 

If we run water at a building tap until the water temperature first feels cold and immediately collect our water sample, we are most likely collecting and testing water that has been sitting in the water service piping between the building and the street water main.

See  WELL FLOW RATE for a detailed explanation of how to calculate the volume of water inside of pipes.

Also see our review of a Home Test Kit for Lead in on building surfaces located at LEAD TEST KIT for HOME USE. The same company offers a lead-in-water test, as do local health departments and private water testing labs in most cities.

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Continue reading at LEAD IN DRINKING WATER, HOW to REDUCE or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.

Or see LEAD CONTAMINATION HAZARDS in the HOME - home

Or see LEAD PIPES in BUILDINGS

Or see LEAD PIPES in BUILDINGS

Or see LEAD in WATER, ACTION LEVELS

Or see WATER TREATMENT EQUIPMENT DISINFECTION

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