Drinking Water Quality

    LWSD has a water quality testing program to manage drinking water fixtures district-wide. All drinking water fixtures are sampled on a four-year cycle for lead content, utilizing the standards from the EPA and the district.

    Water Quality Testing Reports (4-year cycle)

    5 Steps of water sampling process infographic

    Frequently Asked Questions

    What is Lake Washington School District doing about lead in drinking water?

    Recent news coverage has raised the issue of lead in drinking water in general and specifically in schools.

    The district has a program to test water quality in schools every four years. The district works with an outside testing company to collect and test drinking water samples. The testing company employs Certified Industrial Hygienists and follows EPA lead testing protocols. In addition, new school buildings are always tested before occupancy.

    What is lead?

    According to the EPA, lead is distributed in the environment through both natural and man-made means. Today, the greatest contributions of lead to the environment stem from past human activities. Sources of lead exposure include:

    • Lead-based paint
    • Lead in the air from industrial emissions
    • Lead in soil from past emissions due to leaded gas as well as lead paint chips and dust
    • Lead in industrial or consumer products or food, which can be found in some imported candies; medicines, dishes, toys, jewery and plastics or byproducts of lead production
    • Lead in water

    How is it determined if levels of lead are too high?

    To protect public health, the U.S. Environmental Protection Agency (EPA) has set standards for drinking water for lead. They recommend schools take action to reduce the level of lead when found above 20 parts per billion (ppb). LWSD has set a lower threshold to take corrective action on fixtures that test over 15 ppb, as an additional precaution. The EPA’s level is not a measure of health effects. It serves as a signal to take steps to reduce lead in the water.

    What has Lake Washington found in its water testing so far?

    The majority of faucets tested have shown little or no lead. Testing has also shown that interior plumbing is not the cause of elevated lead levels in schools tested. In cases where elevated levels of lead have been found, the primary source has been identified as particles that have built up in faucet aerators. As a result, the district is beginning a routine maintenance program to clean aerators three times each year. Some situations have been addressed by repair or replacement of faucets, fixtures or supplies lines.

    How does lead get into drinking water?

    Lead may get into drinking water in two ways: 1) by being present in the source water, such as coming from contaminated runoff or, 2) water pollution or through an interaction between the water and plumbing materials.

    Public water systems that provide water to schools and homes in our area meet strict guidelines for testing their water sources and meet federal and state public health standards for lead. Some lead may get into the water from the distribution system – the network of pipes that carry the water from the public water system source to homes, businesses, and schools in the community. Interior plumbing, soldered joints, leaded brass fittings, and drinking water fixtures that contain lead materials are the primary contributors of lead in drinking water.

    How does water testing for lead work?

    A sample of water is taken and tested by a certified laboratory. Tests are conducted on a prioritized sample basis, which includes collecting samples from drinking fountains (both bubbler and water cooler style), kitchen sinks, classroom combination sinks and drinking fountains, home economics room sinks, teachers’ lounge sinks, nurse’s office sinks, sinks in special education classrooms, and any other sink known to be or visibly used for consumption. Fixtures generally not used for consumption such as bathroom sinks, laboratory sinks, or mop sinks are not tested. Laboratory analysis test results indicate any levels of lead found in the water sample. These levels are stated in parts per billion (ppb).

    How do you determine where elevated levels of lead may be coming from?

    EPA testing protocols are developed to help determine the source of lead. Identifying the source of lead allows appropriate steps to be taken to reduce any elevated lead levels. These tests confirm if lead is coming from:

    • The public water source. This testing is conducted by the public water providers.
    • The public water source distribution system. This requires water sampling at the point of entry from the street to the school or residence. Due to its cost, this testing is generally only conducted if other testing below fails to identify sources of lead.
    • The internal building plumbing piping. Testing for sources of lead in internal building piping is done through what is called a “flush” sample which is collected after water has run for 30 seconds. This sampling approach is designed to analyze the lead content in the water in the plumbing behind the walls.
    • The supply lines, fixtures, faucets and fountains. Testing for lead from these sources is done by a “first draw” sample which pulls a stagnant water sample before any flushing or use occurs and after water has remained stagnant between 8 and 18 hours in an outlet or fixture.

    What can you do to reduce lead levels if it is found to be elevated?

    Depending on the source of lead, different steps are taken to reduce lead levels. The district is working with a certified industrial hygienist who recommends the appropriate remedial actions if elevated levels of lead are found. Generally, lead in plumbing fixtures outside the building walls may be addressed by flushing supply lines, cleaning particles, which can build up in faucet aerators, or replacing fixtures and/or supply lines. Addressing sources of elevated lead coming from internal building piping is more difficult. It may require adding filter systems or replacing or lining interior plumbing. Flushing (running water from the tap for several minutes) is an EPA-recommended short-term control measure so that faucets found to have elevated lead levels can be used after this initial flush each day.

    How do you know if measures taken to reduce lead have been effective?

    After corrective measures are taken to reduce lead, a follow-up water sample is collected and tested. If test results continue to be above the action level, additional corrective measures are taken and retesting is done until the levels are no longer elevated.

    Should I do anything at home to reduce lead exposure?

    School water is not the only potential exposure to lead for staff and students. Lead may also be in drinking water at home. Here’s what the Washington State Department of Health recommends:

    • If you live in older housing built before the mid-1940s, it is recommended that you run your tap at least 2 minutes after water has sat in the pipes for 6 hours or more. This will help flush out any lead that may have accumulated in your pipes.
    • If you live in newer housing and are concerned about lead, you can flush your pipes by running your tap until the water is noticeably cooler.
    • Use only cold water for drinking, cooking, and making baby formula. Hot water may contain higher levels of lead.
    • Clean the screens and aerators in faucets frequently to remove captured lead particles.
    • Use only “lead free” piping and materials for plumbing when building or remodeling.

    Where can I find more information about lead?

    Please visit the Washington State Department of Health web page on lead frequently asked questions and resources and the Environmental Protection Agency's web page on lead in drinking water.