SITUATION: An overall expansion program of municipal utilities, covering nine phases of construction over a ten-year period, is in part responsible for the unprecedented growth experienced by municipalities throughout Martin County, Florida. The complete project involved providing both potable water and central sewer availability to more than 60,000 single-family equivalent lots; 820 miles of potable water and low-pressure sewer main installation, and over 75 residential sanitary sewer lift stations within existing residential neighborhoods. The project is valued at over $81 million.

 

METRICS: At issue is one phase of the project tying Martin County’s water pumping and distribution system together in a drilling bore under the St. Lucie River. The 4,400 foot pipeline is one of the longest and most challenging of its kind ever attempted.

 

ENGINEER: Culpepper and Terpening, Inc.

 

OWNER: Martin County, Florida

 

CHALLENGE: The directional drilling project is not only one of the most complex Environmental Crossings, Inc. (ECI) has faced in its worldwide work, but it’s also the longest. The goal is to join two drill bores over a 4,400 foot span from opposite sides of the river and 80 ft. beneath it.

 

 

 

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Following days of preparation in the form of research, computer calculations, 3- dimensional visioning technology and complex mathematical algorithms, ECI’s drill team purposefully dug into a riverbank in North River Shores and started heading for a point in Seagate Harbor, some 4,400 feet to the south. Similar to other challenging directional drill projects of this kind, the drilling head was guided by an engineer using electronic data relayed from the bit and part of a sophisticated computer program.

 

Some 3,600 feet into the drill, pressure needed to steer the bit began to ebb, the result of two 50-degree turns the drill had to make underneath the river bed.

 

At that point, the ECI drill superintendent and his crew made the decision to drill from the opposing south side of the river in an attempt to link with the bore hole they had already made. The super admitted that it might be a long shot. “I was nervous,” he recalls. We’ve done an intersect like this before, but never one that far out or in a curve.”

 

The gamble paid off. Following over two days of intense mathematical calculation and nimble drilling, the two drill bits met through bore holes----80 ft. underneath and halfway across the St. Lucie River.

 

“It’s like two shooters simultaneously firing rounds skyward,” explains Bruce Basher, ECI’s VP of Operations, “and having the bullets collide with one another in the arc. Bumping the bits together like we did was an extraordinary engineering feat, one that stands to this day.”