Experiments were conducted to study the effect of a pH ≥ 9.0 and a low total inorganic carbonate (TIC) concentration of 10‐80 mg as CaCO3/L on lead solubility. The results were compared with those of earlier experiments in which the pH was 8.0–8.5. In the experiments that had pHs ≥ 9.0, lead leaching was reduced, as was consumption of both residual free chlorine and dissolved oxygen. The results closely followed the predictions of a solubility model that allowed for aqueous lead complexation and control by the solid basic lead carbonate under the experimental pH and TIC conditions.

Twelve faucets, representing various designs, materials of construction, and manufacturers, were studied in the laboratory to develop additional information about the leaching of lead and other metals from common kitchen faucets. It was found that new cast‐brass faucets could contribute lead to drinking water in excess of the proposed no action level of 10 μg/L. Also, 60–75 percent of the lead leached from a faucet appeared in the first 125 mL of water collected from the faucet. After 200–250 mL of water had flowed, 95 percent or more of the lead had normally been flushed from the faucet. Determining the maximum lead concentration from a faucet requires that both cold and hot water sides of the faucet be sampled and that the samples be no larger than 100–125 mL.