Generation, use, and treatment of new and unique process waters in or for wet-process phosphoric acid manufacturing to substantially eliminate discharge of contaminants to the environment. Acid pond water from conventional wet-process phosphoric acid manufacturing, contaminated with compositions containing fluorine, heavy metals, and radioactive elements such as radium-226, plus residual P.sub.2 O.sub.5, is superseded. Substantially all contaminants from the wet-process are insolubilized and removed, whereas P.sub.2 O.sub.5 normally lost is recovered. Decontaminated gypsum stack water with a mildly acidic pH results from stepwise raising of wastewater pH, with clarification, and subsequent re-acidification, to provide a decontaminated process water with slightly acidic pH adapted to match the pH of environmental ground water. The process is made more economical, while enhancing protection of surrounding air, soil, and water from contaminants.