Lake Youngs Copper sulfate spraying and spreading equipment designed and built by Water Department employees - 3-16-1954 - Water Department brochure - Waterworks Engineering May 1954 - prints and negatives, 1954 - 1954, Box: 1, Folder: 03631-03639. Water Department Photographic Negatives, 8200-13. Seattle Municipal Archives. https://leglas100/finding-aids/repositories/2/archival_objects/194013 Accessed June 02, 2026.