Abstract: Soda values are recovered from waste water and impurities are rejected to bitterns ponds by a low temperature crystallization process. In the process, waste water, typically containing 7-14% equivalent soda ash, is reacted with lime to neutralize bicarbonate. The liquor is subsequently clarified and fed into a multiple effect evaporator cooling circuit where it, along with the recirculating cooling water, is heated. The heated clarified liquid is then fed to an evaporative cooling system. Water is evaporated in the cooling tower and the liquor is cooled. The effluent liquor from this system now contains 17-24% soda ash. Most of this stream is recycled back to the multiple effect evaporator's cooling circuit for reheating. Approximately 10% of this stream is fed forward to an air cooled cooler-crystallizer where sodium carbonate decahydrate is crystallized. The decahydrate crystallized is relatively pure, while the sulfate is concentrated in the mother liquor.