The plumes of white steam that have filled the sky over the city of Georgetown since 1937 will vanish by the end of the year. International Paper Co. announced Thursday that it will close the mill, which has 526 hourly and 148 salaried employees. "This decision is especially difficult because of the impact on hard-working employees, their families and the surrounding communities," the mill manager, Bernie Chascin, said in a statement. The employees will be offered severance benefits, outplacement services and access to mental health resources, the statement said. The closing was announced along with a review of "strategic options" for IP's $2.9 billion global cellulose fibers business, which has eight mills in three countries. It produces absorbent pulp for personal care products and as a raw material for textiles, construction materials and other items. The Georgetown mill produces 300,000 tons of the material, also known as fluff pulp. Production will be transferred to other mills. The mill also produces "uncoated freesheet papers" for Sylvamo, a company that was spun off from IP in 2021. Sylvamo, which is based in Memphis, Tenn., along with IP, said on Thursday that it was terminating its contract for the Georgetown mill's product, which was about 250