Here’s who is – and isn’t – using micro-trenching for their fiber builds

Fiber rollouts are ramping up across the U.S., but the way companies are planning to get their infrastructure deployed varies. Of course, there are the traditional aerial and boring methods, but some are also opting for a technique called micro-trenching. Proponents of micro-trenching claim it allows them to move faster and cause less disturbance to residents in the communities they’re building to. But others are steering clear of the approach, citing long-term maintenance issues, among other things.

Micro-trenching refers to the practice of cutting thin channels about 1 to 3 inches wide and 6 to 24 inches deep into roadways and other rights-of-way in which to lay fiber. Once the cable is installed, the channels are backfilled with asphalt or another matching filler material. Gary Bolton, CEO of the Fiber Broadband Association (FBA) told Fierce such trenches are able to accommodate up to 2,000 strands of fiber. In a blog from November 2021, Ting Internet noted micro-trenching teams can lay as much as 3,000 feet of conduit per day, compared to around 500 feet using traditional construction methods.

The approach is nothing new. Back in 2016, AT&T touted fiber as a key part of its FTTH installation process, telling Fierce at the time that the approach had been an industry standard for the past decade. Frontier Communications (pre-bankruptcy) and Google Fiber also talked up micro-trenching the same year. And Bolton noted micro-trenching has been used for rollouts in major cities including New York, Chicago, Los Angeles and Nashville.

Daniel Levac is National Sales Manager for fiber optic cable manufacturer Preformed Line Products (PLP) and sits on FBA’s Deployment Specialists Committee. He told Fierce that while micro-trenching has indeed been around for a while, techniques have improved over time to become cleaner and less invasive than in the past. While there are a variety of factors that can contribute to the cost of micro-trenching – including geography and geology – he argued it’s generally a cost-effective deployment method. He added the biggest hurdles to deployments which use micro-trenching are outdated municipal regulations and a lack of knowledge about the approach among local officials.

Asked how widely used micro-trenching is, John George of FBA’s Technology Committee explained “most below grade installations are by directional boring or direct trenching” but micro-trenching is “sometimes used when those methods are cost prohibitive.”

“Where pole attachments are difficult or unavailable, or the subsurface is rocky or rock, micro-trenching can be faster and lower cost than other options,” he stated.

In the trenches

AT&T still uses micro-trenching today, but it no longer appears to be an integral part of its fiber plans. Adam Schieber, AT&T VP of Construction and Engineering, told Fierce that these days micro-trenching “is a niche solution in our toolbox” and not something it uses at scale. He added part of the reason it is relegated to specific local use cases is because AT&T is using custom fiber for most of its large build projects.

“The pre-spliced tethers on our fiber cables are too large for a micro-trench, so along with requiring special equipment and materials, micro-trenching isn’t a solution that fits broadly into our build,” he said.

Google Fiber has also continued using micro-trenching over the years, despite being forced to abandon its network in Louisville, Kentucky in 2019 after a trial of a shallower version of the approach went wrong. Earlier this month, Google Fiber announced plans to use micro-trenching for a network rollout in Mesa, Arizona.

Open access fiber provider SiFi Networks is also planning to use micro-trenching in Mesa as well as for another network rollout in Saratoga Springs, New York. And Ting Internet has also been outspoken about its use of micro-trenching.

“Micro-trenching is not a temporary fix, and, done properly, it doesn’t sacrifice longevity for build speed,” it stated in the aforementioned blog. Ting also said micro-trenching is faster and cheaper than traditional build methods.

Ziply Fiber, which is planning to cover more than 1 million locations across its footprint over the coming years, hasn’t used micro-trenching yet, but CEO Harold Zeitz told Fierce it is planning to. While Zeitz said stringing aerial fiber “continues to be the lowest cost method” of deployment, he noted “micro-trenching can be less expensive than boring” in a number of instances. He also echoed assertions that micro-trenching is faster and less disruptive than other underground deployment alternatives.

Likewise, Shenandoah Telecommunications (Shentel) executives said they're open to using micro-trenching, but to date haven't found an instance where it makes more financial and operational sense than using traditional bore, bury or aerial deployments. That could change if circumstances evolve such that micro-trenching offers some sort of competitive advantage, they added.

Frontier Communications SVP of National Architecture and Engineering Scott Mispagel similarly said micro-trenching is one option in its toolbox but is "not a silver bullet for every deployment."

"In the right situation, it can be faster, but it must be used in those right situations," he said.

Not sold

While it used to employ the technique, a Lumen Technologies representative told Fierce it no longer uses micro-trenching because of long-term maintenance issues related to road deterioration.

“We found the cost of this maintenance can be higher than using other construction methods,” the Lumen representative said, adding those issues can’t be resolved by using deeper trenches. “We’ve also seen other service providers attempting to trench deeper and experiencing similar maintenance issues.”

Meanwhile, a WOW! representative told Fierce it currently “has no plans to use micro-trenching technology for its fiber builds. All placement will be directional bore.”