One of Seattle’s oldest businesses is also one of its biggest polluters.
For anyone crossing the Duwamish River on the West Seattle bridge, the Ash Grove Cement plant is hard to miss.
Its pair of giant concrete domes and eight-pack of tall silos jut above the low warehouses of Seattle’s industrial Sodo district. Small hills of limestone, gypsum, and other raw materials barged in from Canada line the riverfront. The plant’s 27-story cooling tower, adorned by an illuminated American flag, dwarfs even the silos…