Background: Federal Regulation of Lead in Drinking Water
As the crisis in Flint, Michigan has unfolded, there has been a renewed focus on lead and other contaminants in drinking water. For an overview of lead in drinking water, see this page. The Federal Government regulates lead in drinking water, primarily through the Lead and Copper Rule.
Lead and Copper Rule
Adopted as part of the Safe Drinking Water Act (SDWA) in 1991 by the Environmental Protection Agency (EPA) the Lead and Copper Rule (LCR)'s purpose is to protect public health by minimizing lead and copper exposure at the tap.
The LCR requires water systems to monitor the drinking water they provide and control for corrosion. Because lead can get into drinking water at various points throughout the system, as well as in home or building plumbing, the rule requires testing and treatment to minimize lead leaching from pipes, fixtures and solder. The rule also requires public education to help consumers reduce lead exposure at the tap.
The Lead and Copper Rule is different from many other drinking water regulations, which set enforceable maximum contaminant levels (MCL’s) based on health effects and feasible treatment options. The LCR does not mandate drinking water to stay below maximum lead or copper levels because these contaminants enter drinking water after it has left the water treatment plant.
Instead, the LCR uses a “treatment technique” approach which requires water systems understand the potential for lead and/or copper exposure in their system and take various actions, including treatment, to reduce exposure. This involves sampling and testing.
Water systems must collect samples at the tap at homes and businesses they serve and test for lead and copper levels. The number of required samples is determined by the size of the water system.
Lead and Copper Tap Sampling Basics
- “First draw” samples must be collected after water has had time to sit in the pipes for at least 6 hours.
- Samples must be taken every 6 months, unless the system qualifies for reduced monitoring – available to systems that have not exceeded the action levels for multiple 6 month sampling periods
- Samples must be taken at high risk homes, which are likely to have lead service lines.
- Samples are used to determine whether or not lead or copper is present at the tap, and to indicate effectiveness of corrosion control treatment.
- The LCR sets 90th percentile action levels of 0.015 mg/L for lead and 1.3 mg/L for copper.
- Sampling protocols are designed to capture a statistical representation of lead in the system and likeliness of corrosion, not to determine how much lead is in the water that is consumed throughout the system.
- For more, see EPA’s latest tap sampling guidance here.
The results can indicate whether corrosion control treatment (CCT) to prevent lead leaching is effective, and whether or not lead is present at the tap. A statistically significant number of samples exceeding the action level (AL) is an indication that existing corrosion control treatment is not adequate and further action is needed.
Specifically, if lead concentrations exceed the action level of 0.015 mg/L for lead and 1.3 mg/L for copper in more than 10% of taps sampled, then the system must take a number of actions, depending on the frequency and magnitude of exceedances, including: additional monitoring, corrosion control treatment, public education, and lead service line replacement.
Corrosion Control Treatment Basics
- Corrosion control treatment can come in many forms, including the addition of chemicals which create a barrier between pipes and water, or modification of water chemistry, such as changing the ph or hardness to inhibit corrosion.
- The most common chemical additives used for corrosion control treatment are orthophosphates which coat lead pipes to prevent leaching.
- All water systems that serve more than 50,000 people must use corrosion control treatments.
- If a system exceeds the action level, then it is required to optimize its corrosion control treatment.
- See EPA’s optimal corrosion control recommendations here.
Other key elements of the Lead and Copper Rule include public education and lead service line replacement. Public education in the LCR and actions by the consumer are critical to reducing lead exposure at the tap.
If the action level for lead is exceeded, water systems must issue public education materials as soon as possible, and at a minimum within 30 days after the system learns of tap monitoring results. Materials must be distributed to each household served by the system. Posters must be located in public buildings. Public education includes basic information on health impacts of lead and how it gets into drinking water. It also must include steps that individuals can take to reduce lead exposure at the tap. EPA instructs water systems to include the following instructions in their public education materials:
- Run tap water to flush out lead
- Use cold water for drinking, cooking and making baby formula
- Do not boil water to remove lead
- Look for alternative sources or treatment of water.
- Test your water for lead.
- Get your child’s blood level tested
- Identify and replace plumbing fixtures that contain lead.
Lead Service Line Replacement
- Systems that continue to exceed the lead action level after implementing corrosion control treatment must replace lead service lines.
- During periods of action level exceedances, the LCR requires 7% annual replacement rate. States may require an accelerated replacement schedule.
- There are specific monitoring and notification requirements when conducting lead service line replacement.
- A system can stop doing LSL replacement after two consecutive 6-month monitoring periods below the action level.
EPA is considering long term revisions to the Lead and Copper Rule to improve public health protection. Regulatory changes are expected to begin in 2017.
Reduction of Lead in Drinking Water Act
While the LCR applies to water utilities, the Reduction of Lead in Drinking Water Act, prohibits the use of pipes, plumbing fittings, fixtures, solder and flux that contain more than 0.25% lead as a weighted average. The current “lead free” standard of 0.25% was established in 2011, and became effective in 2014. From 1986 until 2014, “lead-free” fixtures could contain up to 8% lead. As a result, older homes are more likely to contain lead plumbing and fixtures.