Long-Term Behavior of Simulated Partial Lead Service Line Replacements

Area of Science:

• Environmental Science
• Public Health
• Materials Science

Background:

• Lead service lines are a source of lead in drinking water.
• Partial replacement with copper can create galvanic corrosion.
• Understanding lead release from different pipe configurations is crucial for public health.

Purpose of the Study:

• To assess long-term impacts of copper-lead galvanic connections on lead release.
• To compare lead release from different lead service line configurations.
• To evaluate the influence of flow rate, connection types, and sampling on lead release.

Main Methods:

• A 48-month pilot study tracked lead release from three configurations: 100% lead, 50% copper/50% lead, and 50% lead/50% copper.
• Varied flow rates (8 LPM, 32 LPM), connection types, and sampling methodologies were used.
• Lead accumulations near junctions were temporarily removed to assess risk reduction.

Main Results:

• Elevated lead release from galvanic corrosion worsened over time, with 140% more lead release in partial replacements at 14 months.
• Partial replacements released ~40% more lead than 100% lead pipes even at moderate flow rates.
• At high flow rates, 100% of samples from partial replacements exceeded health thresholds, versus 0% for 100% lead pipes.
• Brass compression couplings significantly increased lead release (up to 10x).

Conclusions:

• Partial lead service line replacement can exacerbate lead release due to galvanic corrosion.
• Flow rate and sampling methods significantly impact lead detection.
• Mitigation strategies like removing lead deposits can reduce risk.
• Further research should consider whole-house filters for particulate lead release quantification.