What Is Lead and Where Does It Come From?

Lead is a toxic heavy metal that has no beneficial biological function in the human body. Unlike most water contaminants, lead in drinking water rarely originates from the source water itself. Instead, it enters the water supply through corrosion of lead-containing plumbing materials between the water treatment plant and the consumer's tap.

The primary sources of lead in drinking water include lead service lines connecting water mains to buildings, lead solder used in copper pipe joints (common in construction before 1986), and brass or chrome-plated brass faucets and fixtures. Galvanized steel pipes that were previously connected to lead service lines can also release lead.

The Flint, Michigan water crisis beginning in 2014 brought national attention to lead in drinking water when a change in water source without adequate corrosion control caused lead to leach from aging pipes into the water supply, exposing over 100,000 residents to elevated lead levels. This event underscored the critical importance of corrosion control treatment and infrastructure maintenance.

Water chemistry significantly influences lead leaching rates. Corrosive water characterized by low pH, low alkalinity, and low mineral content dissolves lead more aggressively from plumbing materials. Temperature and stagnation time also affect lead concentrations at the tap.

Health Effects of Lead in Water

Lead is a cumulative toxicant that affects multiple body systems. The U.S. EPA has determined that there is no safe level of lead exposure. Lead is classified as a probable human carcinogen (Group B2) by the EPA.

In children, even low levels of lead exposure can cause irreversible neurological damage, including reduced IQ, learning disabilities, attention deficit disorders, and behavioral problems. The CDC uses a blood lead reference value of 3.5 micrograms per deciliter to identify children requiring intervention.

In adults, chronic lead exposure is associated with hypertension, kidney dysfunction, reproductive effects including reduced fertility in both men and women, and cardiovascular disease. Pregnant women are at particular risk because lead stored in bone can be mobilized during pregnancy and transferred to the developing fetus.

Lead accumulates in the body over time, primarily in bone tissue, where it can have a half-life of 20 to 30 years. This bioaccumulation means that even low-level chronic exposure can result in significant body burden over time.

Regulatory Limits for Lead in Drinking Water

The EPA regulates lead under the Lead and Copper Rule (LCR), which requires action when more than 10% of tap water samples exceed the 0.015 mg/L action level. The EPA Maximum Contaminant Level Goal (MCLG) for lead is zero, reflecting the scientific consensus that no level of lead exposure is without risk.

How to Test for Lead in Water

Lead cannot be detected by taste, color, or odor. Testing requires collection of first-draw samples (water that has been standing in pipes for at least six hours) and analysis by a certified laboratory using EPA Method 200.8 (ICP-MS) or EPA Method 200.9 (GFAAS).

First-draw sampling is critical because lead concentrations are typically highest in water that has been in contact with lead-containing plumbing for extended periods. Sequential sampling protocols that collect multiple samples at different flush times can help identify whether the lead source is the service line, interior plumbing, or fixtures.

Treatment Methods for Lead Removal

Reverse Osmosis

Reverse osmosis systems are among the most effective technologies for lead removal, achieving rejection rates of 95% to 99%. RO is effective for both dissolved lead (Pb2+) and particulate lead, making it suitable as a point-of-use barrier for residential and commercial applications.

Ion Exchange

Cation exchange resins and lead-selective resins can effectively remove dissolved lead from water. This technology is particularly effective in point-of-entry applications where consistent lead removal is required across all water outlets in a building.

Activated Carbon Filtration

Certain specially formulated activated carbon block filtration systems are certified for lead reduction. However, not all carbon filters are effective for lead removal. Only filters specifically certified to NSF/ANSI Standard 53 for lead reduction should be used for this purpose.

Corrosion Control

At the municipal level, corrosion control treatment using orthophosphate or pH/alkalinity adjustment is the primary strategy for reducing lead leaching from distribution system piping. Chemical treatment solutions for corrosion control are essential for any system with lead-containing infrastructure.

Distillation

Distillation effectively removes lead from water by evaporating and recondensing purified water. While effective, it is energy-intensive and typically limited to small-scale applications.

Frequently Asked Questions

What is the safe level of lead in drinking water?

The EPA has established an action level of 0.015 mg/L (15 ppb) for lead in drinking water. However, the EPA states that there is no safe level of lead exposure, particularly for children. The WHO guideline value is 0.010 mg/L (10 ppb).

How does lead get into tap water?

Lead enters tap water primarily through corrosion of lead service lines, lead solder in copper pipe joints, and brass fixtures. This is especially common in homes built before 1986 when lead solder was banned. Corrosive water with low pH or low mineral content accelerates lead leaching from plumbing materials.

Can boiling water remove lead?

No. Boiling water does not remove lead. In fact, boiling concentrates lead by evaporating water volume while the dissolved lead remains. Effective lead removal requires reverse osmosis, distillation, or specialized filtration media designed for lead reduction.

Need to Remove Lead from Your Water?

ForeverPure offers commercial and industrial water treatment systems designed for lead removal, including reverse osmosis units, ion exchange systems, and corrosion control chemical feed equipment. Our engineers can recommend the optimal solution based on your water analysis, flow rate requirements, and application.

Contact ForeverPure for a customized lead removal solution.