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.

The American National Standards Institute/NSF Standard 61, Section 8, is intended to protect the public from inline brass plumbing products that might leach excessive levels of lead to potable water. Experiments were conducted to examine the practical rigor of this test. Contrary to expectations, the test was not highly protective of public health. In fact, results indicated that small devices made of pure lead—which pose an obvious public hazard—can easily pass the leaching protocol. Reforms are needed to help prevent such unacceptable outcomes in the future. Brass devices passing the test can contribute to lead levels at the tap in residences, schools, and other buildings.