The Rondout West Branch tunnel of the Delaware Aqueduct provides up to 900 million gallons per day of drinking water to New York City. Various studies have confirmed that the 60 year old structure has developed leaks in the vicinity of Roseton in the mid-Hudson Valley, approximately 60 miles north of New York City. An investigative program was developed which included a long directionally drilled borehole to gather hydrological and geotechnical information on areas of suspected leakage. This paper highlights some of the technical and contractual challenges faced in drilling a borehole in close proximity to a deep pressurized structure. As well as discussion on the drilling and investigative methods, this paper outlines the success at maintaining good directional control on the hole while at the same time recovering valuable data on ground conditions.
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机译：Delaware Aqueduct的Rondout West Branch隧道为纽约市每天提供高达900万加仑的饮用水。各种研究证实，60岁的结构在哈德森谷中半年罗斯顿附近发达了泄漏，大约在纽约市北部约60英里。制定了一个调查计划，其中包括长向钻孔的钻孔，以收集有关涉嫌泄漏区域的水文和岩土信息。本文突出了钻孔钻孔靠近深加压结构钻孔的一些技术和合同挑战。除了钻探和调查方法的讨论中，本文概述了在孔上保持良好定向控制的成功，同时在地面条件下恢复有价值的数据。
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