What easily could have been a run-of-the-mill sewer pipeline replacement project in Oregon went from underground to underwater—creating what participants say will be the world’s first buoyant gravity line. Photo: Brown And Caldwell Pipeline under construction in Lake Oswego, Ore., will be the world’s first buoyant-gravity line when completed next April. Now under construction, the Lake Oswego interceptor sewer boasts 17,000 ft of wastewater-carrying pipe and another 12,000 ft of attached air-filled buoyant pipe. Replacing an existing submerged concrete pile-supported pipeline built in 1963, the new system will hook to the city’s current system on both sides of the lake.
On Dec. 15, the California Natural Resources Agency, U.S. Dept. of the Interior and four other agencies released the Bay Delta Conservation Plan, calling for construction of a $13-billion tunnel to bring water from northern California to the Central Valley. Large Image The multi-agency study looked at alternatives to the 100-year-old delta levee system that would preserve water shipments to the southern part of the state without damaging the delta ecosystem and killing fish. Studies point to the intake pumps in the San Francisco Bay Area as a primary source of large-scale fish mortality in the region. “The current infrastructure
Within a few seconds in mid-December, engineers at a new research facility in Vicksburg, Miss., sealed a 2,000-cu-ft-per-second torrent of water pouring through a 40-ft-wide, eight-ft-deep levee breach using a 100-ft-long, 15-ft-dia., air- and water-filled fabric tube rolling in the stream. Photo: Angelle Bergeron For ENR Full-scale trials of a 100-ft-long levee plug at a new test facility in Vicksburg show technology and techniques for rapidly sealing levee breaches are ready for business, but funds are lacking. Graphic: Courtesy ERDC A 2.2-million-gal source pool and collapsible weir on the test basin simulate a breach. Related Links: Ready To Roll: Levee
The Sacramento Regional County Sanitation District may have to spend more than $2 billion over the next 10 years to improve water quality. The Central Valley Regional Water Quality Control Board on Dec. 9 directed California’s capital city to remove ammonia and other residual materials from treated water before discharging it into the Sacramento River. The city’s 28-year-old plant releases as much as 180 million gallons of water per day into the delta-feeding waterway. The controversial decision came after a contentious permit renewal process in which SRCSD estimated that, between the capital improvements, pilot studies and reports, rates for its
Three Indian firms and an Indian/Spanish joint venture are competing with three Chinese firms for a portion of a hydropower project in Nepal. Larsen & Toubro Ltd., Jyoti Structures Ltd. and KEC International Ltd. are the Indian firms. The joint venture is composed of Spain’s Cobras Instalaciones Y Servicios and India’s Aravali Infrapower Ltd. The short-listed Chinese firms are Sinohydro Corp., Central China Power Grid International Economic and Trade Co., and Shanghai Electric Power Transmission and Distribution Engineering. The Upper Tamakoshi Hydroelectric Project is located on the Tamakoshi River in the Dolakha district, about 50 miles northeast of Katmandu. The
Seeking to meet mandated cuts for the discharge of nutrients into the nation’s largest estuary, the Chesapeake Bay, a Maryland wastewater treatment plant and its design, construction and technology team are using what they say is the world’s largest application of a pollutant-reduction technology as part of a $138.7-million facility upgrade. Team officials at the Patapsco wastewater treatment plant in Baltimore say use of the “fixed-film denitrification system” for tertiary treatment at the facility will reduce nitrogen and phosphorous discharges into the Patapsco River by 83% and 85%, respectively. The waterway is a key tributary of the bay, now on
The Hong Kong Water Supplies Dept. has awarded AECOM a $55-million design and construction services contract to reconstruct and upgrade the Sha Tin Water Treatment Works, one of Asia’s largest water treatment plants. Sha Tin consists of two treatment trains. AECOM will oversee the expansion of the South Works to 145 million gallons per day from 95 mgd. The North Works has a capacity of 232 mgd but is not being upgraded. The overall capacity of the two plants will increase to 377 mgd from 327 mgd. Sha Tin provides water to two million people. AECOM will provide detailed design
For the second time in six months, an unexpected intrusion of water and mud has stalled the $447-million construction of a third water intake at Lake Mead near Hoover Dam in southern Nevada. The problem could delay project completion at the drought-ravaged lake by a year and increase costs by “tens of millions,” says a project official. Photo: Courtesy of SNWA Water intake construction project at Lake Mead could face delays and higher costs because of unexpected water and mud 600 ft below ground. + Image The new intake is intended to draw water deeper from the dwindling lake that
By starting work in late November on a $200-million upgrade of its central transmission system, Vancouver is making its first significant investment in the city’s power grid in 30 years. The project includes construction of an oversized three-story substation to meet future capacity needs and a tunnel beneath one of the city’s major waterways. Photo: Courtesy of BC Hydro Upgraded distribution center will take some capacity from three older stations. Marcel Reghelini, BC Hydro senior project manager, says the work is happening in Mount Pleasant, a fast-growing neighborhood no longer adequately served by three aging substations. “We’re putting in a
The lead engineer examining the feasibility of a 900-MW dam in northeastern British Columbia says the proposal holds enormous promise for additional power generation for the province. The Site C Dam would be the third dam along the Peace River. + Image Source: BC Hydro The third impoundment on northeastern British Columbia’s Peace River would provide 900 MW of electricity, but cause a significant loss of habitat, opponents claim. According to John Nunn, technical project director of Vancouver-based engineering consultant Klohn Crippen Berger Ltd., the provincial government is not putting pressure on his company to validate the government’s decision to