COVID-19 Update: Pro-Pipe is ready and on alert to provide supplemental pipeline cleaning services to understaffed cities and sanitary districts affected by increased SSOs caused by improper flushing.
Read More

What Is Horizontal Directional Drilling?

  January 14, 2021

The earliest forms of underground utility lines required trenches to be dug before pipes, lines and cables could be laid. Not only was this a laborious and time-consuming process, but it also became exponentially more difficult in areas where lines already existed.

The practice of horizontal directional drilling began in the 1970s as a means to reduce the cost of installing utilities by digging the entire line’s path. Today, however, the use of horizontal directional drilling (HDD) has enabled municipalities, pipe contractors, utility companies and telecommunications providers to install critical infrastructure under the earth without digging a trench for the full length.

As time went on, there was no real methodology for mitigating cross bores pre and post HDD. Recently sewer pipe condition assessment companies such as Pro-Pipe developed techniques with existing technologies to mitigate cross bores. This gap in time between when HDD first commenced and when mitigation efforts were developed resulted in a large gap of utilities that may have resulted in cross bores.

How Does HDD Drilling Work?

The drilling process consists of three stages:

  1. In the pilot bore phase, a drill bit is pushed into the ground and guided until it reaches a predetermined end point. While this is happening, drilling fluids are pumped into the hole to carry away the soil as well as cool the bit.
  2. As the drill pipe is pulled out, a reaming tool clears dirt and mud until the size of the hole is slightly larger than the pipe to be installed.
  3. Finally, the pipe or utility line is pulled through the hole and put in its intended position. Once it is secured, it is inspected to ensure there are no flaws and the site is restored to its original condition.

Ensuring a Successful Project

Although HDD drilling makes installing pipes and utilities much easier in many ways, it still requires a great deal of care to prevent problems. One of the most significant of these potential issues is cross boring. Cross boring happens when a new HDD project runs through an existing line, such as a sewage pipe or natural gas line.

If the local community has spotty record-keeping and one elects not to dig a trench to uncover existing infrastructure, there is substantial risk of boring through a structure that is already in the ground. This could lead to outages of service and even a dangerous explosion in the case of natural gas lines.

How Pro-Pipe Can Prevent Cross Boring Conflicts

Given how risky it can be to perform horizontal directional drilling without knowing what lies beneath the surface, it is crucial for operators to approach such projects with caution. One of the most important steps that professionals can take for safety is to conduct a full risk assessment. As a leader in sewer pipe inspections, assessments and cross-bore prevention, Pro-Pipe has the expertise to examine an area closely and identify any possible hazards.

Our team can take a close look at your site and point out any spots where a cross-bore inspection would be needed. We can provide solutions before and after any boring takes place. Through our lateral launch sewer lateral locating and mapping, we can ensure the customer knows which areas to avoid when drilling. Plus, we maintain a library of records so the national grid inspection data can be accessed in the future. If you want to learn more about how our services and experience can assist with your HDD needs, get in touch with us today.