Contractors on the centerpiece of San Francisco’s $4.6-billion improvement to the Hetch Hetchy Water System were given notice to proceed on April 1. The five-mile subterranean Bay Division Water Delivery Tunnel planned for under the San Francisco Bay will replace two 1920s and 1930s era pipelines with one 9-ft-dia welded steel pipeline bored as deep as 100 ft under the bay’s floor. The new tunnel will be more secure in an earthquake and a tunnel-boring machine will minimize environmental damage. A joint venture of Michels Corp., Brownsville, Wis., Jay Dee Contractors, Inc., Livonia, Mich., and Frank Coluccio Construction Co., Seattle,
The 2016 Summer Olympics boating and swimming events have put an international spotlight on what has been a long-running problem in Rio de Janeiro—untreated sewage and trash are clogging up major bays and waterways.