Overview

• Experts using January–March 2025 Sydney Water quality data confirmed all monitored parameters in Illawarra region tap water met national safety thresholds.
• Boiling and re-boiling tap water does not change the amounts of inorganic compounds such as metals and salts while allowing only trace volatile organic compounds to escape.
• Modeling indicates that achieving an unsafe lead concentration would require evaporating roughly 20 litres of tap water down to a single 200 ml cup.
• Calculations show fluoride levels in a second cup of re-boiled water rise marginally from about 0.20 mg to 0.23 mg and remain well below health guidelines.
• Automatic shutoff features in household kettles prevent significant evaporation and over-concentration, though some users may notice slight taste changes from mineral shifts or oxygen loss.