Sewer Construction in Miami

Horizontal directional drilling (HDD) continues to be the method of choice for renewing existing urban infrastructure or building it from scratch. Although we see smaller-scale equivalents on many projects in our country (~700 metres long, 500 mm diameter, Deltek projects completed in 2016), the new records being set internationally are extremely promising for the future. One of them, the sewer project in Miami, USA, is a highly significant example.

As is well known, Miami is one of the most important tourism centres not only of the USA but of the world; in 2016 alone it received 15.8 million visitors (see https://partners.miamiandbeaches.com/tools-and-resources/research-and-statistics). That being so, the city’s infrastructure — especially its sewer and wastewater pipelines — is a problem in itself.

Because of the disruption caused during construction, the biggest problem of almost every tourist area is not having enough construction time. City administrations tend to postpone demolition, dumping, construction and similar work as long as possible, or solve it by other means, because it would hurt tourism. But when the city’s pressure sewer line, which had been sounding the alarm since 2013, reached disaster level, the administration decided to take up the scalpel. First the damaged sections were identified with PipeDiver™ and, unfortunately, found to be beyond repair. Then horizontal directional drilling (HDD) was chosen as the most efficient construction method.

Besides the extreme sensitivity of surface activity in the area, another problem was that the section to be renewed sat almost entirely on a high-strength limestone formation. In HDD, rock drilling has always been possible but costly — and it must not be forgotten that it demands more attention and a more professional crew and equipment.

Installing 1,000 metres of 54” (1,355.4 mm) SDR17 HDPE pipe underground through rock in a confined area is a hard job anywhere in the world. A 450-tonne Vermeer (D1000x900) rig, an American Augers P-750 (3,000 l/min) and a Tulsa Rig Iron TT-660 (2,700 l/min) mud pump were used, and the hole was reamed to about 72” (1,807.2 mm).

This project brings together two challenges we frequently meet in Türkiye as well: rock and large diameter. Horizontal directional drilling in a limestone formation calls for a mud motor and rock reamers; at a diameter like 54 inches, the reaming stages, fluid flow and pullback force become the decisive calculations of the project. Deltek carries out this planning together with the client on rock-drilling and large-diameter HDD projects with its Istanbul and Izmir crews; for a similar crossing, contact us.