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Alameda County, CA,

Larry Brooks
Healthy Homes Department
Including the Lead Poisoning Prevention Program

Possible Sources of Lead



Picture of person washing their hands.

The EPA estimates that drinking water accounts for about 20% of our lead intake nationally. For some people, it can be the biggest source of lead exposure. But the problem of lead in water varies significantly throughout the United States. While it may pose a great hazard in Boston; Alameda County's water is relatively lead free. Many people have some knowledge of the problem of lead in water, but they might not know what the lead level is in their home, and what factors influence the concentration.

How Lead Gets in Water

Lead is typically not found in the drinking water at the reservoirs. Lead normally enters the drinking water from service lines, solder in copper piping, and brass faucet fixtures. Until a few decades ago, lead pipe was widely used for the service lines and connections that carry water from street mains to houses.  Lead-based solder was used to join standard copper water pipes until 1988, when lead solder was outlawed. Even today, new brass and bronze faucets can legally be as much as 8 percent lead by weight.  These new faucets normally leach lead during the first five years after installation.  The lead is leached out while the water sits in the pipes and fixtures. California Assembly Bill (AB) 1953 signed into law in September 2006 will reduce the allowable amount of lead in pipes from 8% to .25% commencing in 2010. For more information go to the Laws and Regulations page ("New Bill enacted to reduce lead in drinking water").

Risk Factors

The amount of lead dissolved into the water is affected by the water's acidity, hardness, and temperature. Water in the eastern United States is typically more acidic and softer than water on the West Coast. Therefore Alameda County's water is less likely to leach lead from pipes and solder. Water that has a high concentration of minerals is called hard water. The minerals in hard water eventually coat the inside of the pipes and prevent lead from dissolving into the water.  EBMUD's water is considered to be hard water.  More lead is leached out of pipes and solder when the water stays in pipes a long time, and when the water is acidic, soft, and hot.

EBMUD's Service Lines

Lead pipes are generally found only in homes built before 1930. However, EBMUD began a program years ago of replacing lead service lines installed during WWII. As of 1992, roughly 900 of these lines (0.003% of the District's total) remain in service, but all are scheduled to be replaced.

Lead Studies

A new lead and copper regulation was put in effect by the Environmental Protection Agency in June of 1991.  In accordance with the new regulations, EBMUD began conducting two rounds of sampling at 100 customer homes in May of 1992.  Half of the homes tested had plumbing of lead-soldered copper; half had lead service lines. (About 3,400 homes in the District have such services - about 1 percent of the total.)   This sampling was done in the customers' homes, instead of water leaving the water treatment plant.  Half of the homes had plumbing of lead-soldered copper; half had lead service lines.  All results showed lead levels in the water to be substantially below federal limits.


Federal MCL

State MCL

EBMUD average

EBMUD range





ND - 1

MCL = Maximum Contaminant Limit in parts per billion (ppb)
ND = Monitored for but Not Detected

The Environmental Quality Institute conducted a study of drinking water in homes around the country. It was able to get results for the samples collected in Alameda County.  This study found that seven of the 274 (2.5%) first draw samples had lead levels at or above 10 ppb.  This shows that lead levels are quite low in Alameda County.

In comparison, Consumer Reports conducted a nationwide study and reported their results in February 1993. They found Chicago to have 17% of the first draw samples above 15 ppb. Boston (where the water is very acidic) had 41 % of the first draw samples over the federal standard. New York had 15%,Washington 10%, and Seattle 5% over 15 ppb.

In conclusion, it appears that the water in Alameda county generally contains low levels of lead. It would be rare, but possible, that an individual home in our county would have elevated lead levels in the drinking water. This would most likely be found in a home with newer plumbing or faucets where minerals have not yet coated the pipes or fixtures.

Testing Water in Homes

The only way to really know if a home has high lead levels in the drinking water is to test the water.  Testing for lead in drinking water typically consists of collecting two samples. The first is called a first draw sample. It is collected immediately when the water is turned on after having been off for an extended period of time, usually overnight. If the results of this sample is high, it indicates that lead is leaching from lines within the building.

The second sample is a purged line sample which is collected after the tap has run for one minute to clear the water in the lines. This sample normally shows the amount of lead in water from a source outside the house - typically from the service line.  It usually has a low lead level.  If the purged-line samples show a lead count of more than 5 ppb, there may be lead in the service line.

To find out if the service line contains lead, the water utility or a licensed plumber would need to inspect the service line. Homeowners may legally own some or all of the service line and if they choose to have it replaced, they may have to pay at least part of the replacement costs.

What to Do

If the water has not been tested, or has been found to contain lead levels of more than 15 ppb, there are several things that can be done to reduce ingestion of lead from drinking water.

  1. Do not drink, cook, or make baby formula with water from the hot water tap.

  2. If the cold water hasn't been used for more than two hours, run the tap for a few minutes before drinking it or using it for cooking.  (This water can be saved for watering plants).

  3. In order to conserve water, or if you don't want to flush the lines often, you can keep a jug of flushed water in the refrigerator.

  4. Consider buying a filter certified for lead removal (although,this is not usually necessary in Alameda County), or drink bottled water.

  5. When lead levels are high, if possible, you may need to replace the plumbing or service line, or lead containing faucets.

Boiling the water will not reduce the amount of lead.  Also realize that bathing is not a problem because lead does not enter the body through the skin.

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