| 翻訳と辞書 |
| East Side Big Pipe ： ウィキペディア英語版 |
East Side Big Pipe
The East Side Big Pipe is a large sewer line and tunnel in Portland in the U.S. state of Oregon. It is part of a combined sewer system of pipes, sumps, drains, pumps, and other infrastructure that transports sewage and stormwater run-off to the city's Columbia Boulevard Wastewater Treatment Plant. The East Side Big Pipe project, begun in 2006 and finished in 2011, was the largest of a 20-year series of projects designed to nearly eliminate combined sewer overflows (CSO)s into the Willamette River and the Columbia Slough. The combined projects were completed on time, and they reduced CSOs into the river by 94 percent and into the slough by more than 99 percent.
==History==
From the mid-19th century until the mid-20th century, Portland's combined sewer system poured untreated sewage into the Willamette River and the Columbia Slough. In 1952, the city built its first plant to treat wastewater, which included stormwater run-off as well as raw sewage. However, the existing sewer pipes were often overwhelmed by surges of stormwater from big storms, and the resulting CSOs continued to pollute the river and the slough. In 1991, the city signed an agreement with the Oregon Department of Environmental Quality to nearly eliminate these CSOs.〔"Final Report", pp. 4–5〕
Over the next 20 years, the city took a series of steps to reach its goals: a 99 percent reduction in CSOs into the Columbia Slough by the year 2000 and a 94 percent reduction in CSOs into the river by December 2011. As first steps, the city helped property owners disconnect their roof drains from sewer lines, built separate storm sewers in some locations, diverted surface streams away from the combined sewers, and added sumps and other devices to control surges of stormwater. These relatively low-cost efforts reduced the stormwater entering the system by more than a year.〔"Final Report", p. 6〕
By 2000, the city completed a more complicated project, the Columbia Slough Consolidation Conduit. A separate project completed in 2006 centered on construction of the West Side CSO Tunnel and the Swan Island Pump Station. By late 2011, the city finished the largest of the CSO projects, the East Side Big Pipe. The combined projects were completed on schedule and met the intended goals.〔
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
■ウィキペディアで「East Side Big Pipe」の詳細全文を読む
スポンサード リンク
| 翻訳と辞書 : 翻訳のためのインターネットリソース |
Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.
|
|