Publication Title: 
Water Research
Publication Date: 
Saturday, September 1, 2012

This study considers mandates requiring the partial replacement of lead pipes and the potential impact on rates of lead in the water.

The cumulative mass of lead release indicated that a typical partial replacement configuration did not provide a net reduction in lead when compared to 100 percent lead pipe. The partially replaced service line configuration also had a much greater likelihood of producing water with "spikes" of lead particulates at higher flow rates, while tending to produce lower levels of lead at very low flow rates.

After the first 214 days the galvanic current between copper and lead was only reduced by 34%, proving that galvanic impacts can be highly persistent even in water with optimized corrosion control by dosing of zinc orthophosphate. This experiment raises concern about the low flow rates used during some prior home sampling events, which may underestimate exposure to lead during normal water use, especially when galvanic lead/copper connections are present.

Cartier, C; R.B. Arnold, S. Triantafyllidou, M. Prévost and M. Edwards. Effect of Flow Rate and Lead/Copper Pipe Sequence on Lead Release from Service Lines. Water Research, 46(13) 4142-4152 (2012).