When must I comply with the hexavalent chromium limits?
You must stop adding hexavalent chromium-containing compounds to the circulating water in your cooling tower and meet the 0.15 milligrams per liter hexavalent chromium concentration limit no later than 180 days after the effective date of the regulation. This is the compliance date for the regulation. (f) For how long do I have to test the circulating water? If, after the effective date of this regulation, two consecutive required tests showing concentrations of hexavalent chromium less than 0.15 milligrams of hexavalent chromium per liter of circulating water, then the testing requirement is ended. All other requirements remain the same. The district may, however, require you to resume testing the circulating water at any time if the district has information that the circulating water may contain hexavalent chromium. (g) How do I test the circulating water for hexavalent chromium? You must test the circulating water to determine hexavalent chromium concentrations using American Public
