Abstract: A method for removing contaminants from an aqueous process stream containing ammonium ions and phenol-formaldehyde resin, such as the process stream of a fiberglass insulation manufacturer. One aspect of the method includes mixing sodium hydroxide with the aqueous stream so that the sodium hydroxide combines with the ammonium ions and liberates free ammonia. Another aspect of the method includes mixing calcium hydroxide with the aqueous stream so that the calcium hydroxide combines with the phenol-formaldehyde resin to form calcium phenate. The liberated free ammonia is captured and scrubbed, while the solid calcium phenate is easily removed by filters. The aqueous process stream is then clean enough to be reused.