The nearly decade-long fight over whether to raze or rebuild the Alaskan Way Viaduct on Seattle’s waterfront is nearing a final decision. On Jan. 13, Washington Gov. Chris Gregoire (D) announced that she favors replacing the 55-year-old highway with a $4.25 billion deep-bored tunnel. King County Executive Ron Sims, Seattle Mayor Greg Nickels and Port of Seattle Chief Executive Officer Tay Yoshitani also support the plan. Elected officials have been debating whether to rebuild or replace the viaduct since 2001, when the double-deck freeway was damaged in an earthquake. A month ago, an advisory committee created to study design options

Bechtel Power Corp., Frederick, Md., has received limited notice to proceed and could break ground toward the end of this year on a 1,000-MW coal-fired powerplant in southern Meigs County, Ohio, for American Municipal Power Ohio Inc., Columbus. The AMP Generating Station, to be built under a $3.25-billion engineer-procure-construct contract, will employ ECO-SO2 multipollutant emission control from Powerspan Corp., Portsmouth, N.H., making the plant one of the cleanest coal-fired plants in the country.

Buoyed by the state of Florida’s decision to buy 181,000 acres of land in the Everglades Agricultural Area to reconnect Lake Okeechobee with the lower Everglades, the 300 people attending the Everglades Coalition Conference in Miami on Jan. 8-11 found reasons for optimism in the decades-long battle to protect and revitalize southern Florida’s vast wetland ecosystem despite the gloomy economic climate. Gov. Charlie Crist (R) negotiated to buy the land from United States Sugar Corp., Clewiston, Fla., and announced the deal on June 24. Despite its $1.34-billion cost and the floundering economy, he insisted in a speech to the conference

As the recession grinds on, some consultants are finding an emerging outlet by updating older buildings from power hogs into green stewards. The trend is attracting a fresh round of eco-savvy tenants. Chicago is home to two large projects, examples of advancing efforts to green up existing buildings. In early December, 172 buildings nationwide were certified under the U.S. Green Building Council’s LEED for Existing Buildings Rating System, a program created in 2004. More than 2,000 other buildings are seeking to obtain such certification, according to the Washington, D.C.-based group. Photo: Merchandise Mart Properties Inc. The 79-year-old Mart’s green makeover

The Tennessee Valley Authority has had a second leak at an impoundment at a coal-fired powerplant, this time from a gypsum pond at its Widows Creek Fossil Plant in northeast Alabama. The incident prompted Sen. Barbara Boxer (D-Calif.) to announce on Jan. 13 that she plans to seek federal regulation of coal-ash ponds across the U.S. Shifting gypsum dislodged the cap covering a 30-in. pipe once used to drain water from the gypsum pond into an adjacent settling pond, says John Moulton, a TVA spokesman. Once the cap came off, water in the gypsum pond flowed into the settling pond,

Every fall, during low-water time on the Mississippi River, a crew of about 300 men and women turns out to resume one of the longest-running and most important construction projects of the U.S. Army Corps of Engineers—the placement of articulated concrete mattresses along the levees to prevent scour and protect communities. Slide Show Photo: Angelle Bergeron / ENR The operation requires a river of cable, fed up from below decks. Related Links: Mat Sinking on the Mississippi Photo: Angelle Bergeron / ENR With most new placement done, the casting yards have dwindled from five to three and the specialized units

The normal clutter of braced shoring is absent on a U.K. job to replace viaduct bearings near London because the shoring firm has created a cheaper and simpler megaprop system by bolting together standard stock. “We’ve never made these composite props before,” says Ian Fryer, engineering director for supplier RMD Kwikform Ltd., Walsall. “We hadn’t thought of it.” Photo: RMD Kwikform Ltd. A propping system to support a bridge under reconstruction can handle varying heights and pier configurations. Related Links: Agile Robots Can Climb High Places Replacing the 108 bearings is part of a $9.2-million project to refurbish Country Way

Sustainable features of the Vancouver convention center expansion go beyond daylighting controls, some natural ventilation, the 2.4-hectare green roof with 400,000 plants and grasses and restoration of 200 ft of shoreline and 1,500 ft of marine habitat. There also is a “blackwater” wastewater treatment and reuse system, for plant irrigation and toilets, connected to a roof-top stormwater management and reuse system. Slide Show Photo: LMN Architects Green roof can be irrigated using building’s treated water. Related Links: Stupendous Setting Is Crummy Site Habitat Apron Cooked Up To Mitigate Impact on Marine Life The building, going for a LEED Gold rating,

The foundation engineer calls the $8.2-million artificial reef—the marine habitat apron—the most unusual element of the Vancouver convention center expansion project. “I know of nothing else like it, anywhere,” says Ryan MacPherson, project engineer for WorleyParsons Westmar Consulting Engineers, North Vancouver. “It’s very successful.” Marine life is already growing. Slide Show Photo: LMN Architects Marine habitat apron, an artificial reef, is attached to the marine platform. Precast was placed by barge-mounted cranes. Related Links: Stupendous Setting Is Crummy Site Water Treatment and Reuse Reduces Use of Potable Water The 400-meter-long apron resembles long stadium bleachers, consisting of 86 bays of

Canada’s $730-million Vancouver convention center expansion on the city’s waterfront sits on the best of sites. To the north are breathtaking views of Coal Harbor, Burrard Inlet and the North Shore Mountains. Across the street to the south is the city center. Directly to the west is the landmark Stanley Park. Slide Show Photo: VCCEP Team Related Links: Habitat Apron Cooked Up To Mitigate Impact on Marine Life Water Treatment and Reuse Reduces Use of Potable Water Photo: LMN Architects Building could not block street and park view corridors. But the 106,000-sq-meter project in seismic British Columbia also sits on