To Underground or Not To Underground: That Is the Question




Over the past few years, there’s been much talk in regards to undergrounding electrical utilities, especially following massive weather-related outages such as those caused by Superstorm Sandy or the Blizzard of 2015. Since most people these days are practically dependent on electrical devices, even hours without power can seem like a lifetime and usually trigger the age-old question: why can’t we move our electrical power distribution underground?

Downed power lines after Superstorm Sandy in the flooded town of Seaside Heights, NJ (AP Photo by Julio Cortez)
Downed power lines after Superstorm Sandy in the flooded town of Seaside Heights, NJ (AP Photo by Julio Cortez)

It seems like a realistic task that can vastly improve the reliability of system, especially since weather and tree branches contribute to 40 percent of outages in the U.S. People hitting poles with their vehicles cause another 8 percent. Currently, less than 20% of distribution lines are underground, and most are in urban areas with dense populations or newly developed areas in suburban settings.

In some parts of the U.S., the crowded overhead power lines are reminiscent of Europe’s infrastructure in the 1960s!
In some parts of the U.S., the crowded overhead power lines are reminiscent of Europe’s infrastructure in the 1960s!

While the United States has been reluctant to jump on the underground bandwagon, multiple countries in Europe have taken their power grids beneath the surface. In Germany, for instance, almost all of its low-voltage and medium voltage power lines serving individual homes and apartments are buried underground. Annually, the German power grid averages 21 minutes worth of outages. Uwe E. Reinhardt, an economist who contributes to the New York Times, alleges that much of the electric infrastructure in the Northeast resembles that of Europe … in the 1960s. Of course, it was an easier process for much of Western Europe to retrofit for underground lines. Many cities were rebuilt following World War II, which means their infrastructure is younger than it is in the U.S.

 

Out of Sight, Out of Mind, Not Out of Pocket

The entrance to an underground substation located in Anaheim, CA (Photo by OC Register)
The entrance to an underground substation located in Anaheim, CA (Photo by OC Register)

Here in the states, the reasons NOT to take the grid under the surface always outweigh the reasons to go for it, and most of the time, it comes down to just one reason: cost. Industry studies into the matter have estimated it costs approximately 5 to 10 times as much to bury lines as it does to run them overhead. In 2012, the Edison Electric Institute released an updated version of “Out of Sight, Out of Mind,” an in-depth study on the undergrounding of power lines and circuits. It reveals that while most customers want power delivered to them via underground wires for sake of reliability and aesthetics, the majority are unwilling to pay the cost of undergrounding.

Maybe that’s because that price tag can be quite steep, depending on location. The rule of thumb is about $1 million per mile, but based on certain geography or population density, that cost may be halved or tripled. However, there are some cities that have decided to bury their power lines despite the costs. In Anaheim, California, the city commenced a 50 year project that is gradually undergrounding all lines. They’re also billing their customers an extra 4% on all electric bills for the duration of the project.

 

Positives and Negatives of Undergrounding Power Lines

Using Vault and Manhole Dewatering Equipment would be advantageous
Using Vault and Manhole Dewatering Equipment would be advantageous. (Photo Credit: Brent Sleeper, Flickr)

Whether for or against it, camps from both sides agree on the pros and cons of underground electrical lines, such as:

Pros:

  • More protection from the elements of super storms, such as wind, ice, snow, severe rain. And many experts agree that climate change will cause even more frequent and violent storms in the future than we’ve experienced over the last few years.
  • Less exposure to wildlife, trees and lightning
  • Aesthetically pleasing: gets rid of those ugly poles and overhead congestion
  • Safer O&M for network maintenance, at least in regards to linemen putting themselves at risk by climbing poles

Cons:

  • More prone to flooding and chronic water intrusion
  • Reduced accessibility to lines, making issues more difficult to locate, thus taking more time to repair
  • Geographic landscape limitations (severe frost, different types of rock foundation)
  • Safety hazards that require more specialized training than average lineman receives

 

Protection from Flooding, Debris & Oil Using Dewatering Equipment

Flooding and chronic water intrusion remain a hurdle for undergrounding in many areas. As our last blog post revealed (and what should be common sense), water and electricity just don’t mix, and transformers housed in underground utility vaults are at risk to fires, outages and even explosions if they come in contact with water. Other issues plaguing underground networks include debris and sediment, which can cause blockage or stoppage of pumps placed within vaults to keep water from contacting the equipment, and oil leaks, which may cause certain oil-sensing pumps to shut down and require immediate maintenance.

Luckily, our line of C.I.Agent® Vault Sump Filter systems are an inexpensive, low-maintenance solution for protecting and dewatering underground electrical utility equipment from malfunctioning due to flooding, debris and sediment buildup, and/or oil (or a combination of all three problems). All of the Vault Sump Filter components and dewatering equipiment are custom-made for the specific site, and come in round and square (paneled) configurations. Strong and durable, the Vault Sump Filter Housing shell is composed of white perforated Polypropylene, and can be used as a stand-alone for debris filtration. The Vault Sump Debris and Silt Filter is made of white Nylon Monofilament Mesh fabric capable of filtering down to 100 micron (about the size of a human hair) for dewatering sludge and sediment. If oil and sheen is an issue, check out the Agent-Q Oil and Sheen Filter, which is made of four layers of patented C.I.Agent Agent-Q (U.S. Patent No. 8,986,822) fabric embedded with C.I.Agent Polymers for solidification of hydrocarbons. One layer of Agent-Q generally flows 400 gallons/minute/m2, with an average grab strength of a nominal 60 pounds (ASTM D5034 testing) and a burst strength of a nominal 70 psi (ASTM D3786 testing).

To see our Dewatering Vault Sump Filter systems in action, watch this short animated video. For more information about all of our underground vault and manhole protection and dewatering equipment / solutions, contact us.

 

History 101: Why NYC Switched To an Underground Electrical Infrastructure

NYC-Before-After-Undergrounding

Think Sandy or Irene were the first major storm systems to wreak havoc on the Big Apple? Think again. The legendary Great Blizzard of 1888 pounded across the Northeastern states, delivering 20 to 60 inches of snow from early morning on March 12 until finally dissipating on March 14. Blistering winds of up to 60 mph and temperatures in the single digits combined to create the perfect storm, paralyzing the city’s transportation and electric lines for days and contributing to 400 deaths and millions in property damage.

But in the cold light of day following this Nor’Easter’s unwelcome visit, the parting clouds offered a silver lining. Most of the power outages could have been avoided, as they were caused by damage to overhead telegraph, electric and telephone wires. Within a year, NYC Mayor Hugh Grant ordered most of the city’s wires buried. And the inability to travel by rail or streetcar for days was a key factor in the creation of the country’s first underground subway system, which debuted in Boston in 1897.

 

Underground Cities, Real and Legendary

Undergrounding electricity may seem like a new and novel idea, but the concept of “going underground” has been around throughout history … thousands of years, in some cases. Here are a few subterranean networks of note, both real and legendary.

 

The Underground Cities of Turkey

derinkuyu_map

The Cappadocia Region, in the Middle Eastern country of Turkey, is home to a number of underground cities carved from the sedimentary rock and volcanic ash deposits common to the area. Historians disagree on both who built them, and when they were built. Some believe the networks were constructed by the Phrygians in the between the 8th and 7th centuries BC, but others think the tunnels may be much older, made at the hands of the Hittites between the 15th and 12th centuries BC. The purposes of these cities are also unknown, though most experts believe they were built to provide protection from enemies as well as the harsh climate of the region.

First unearthed in the 1960s, Derinkuyu, one of the largest underground cities ever discovered, could have potentially housed up to 20,000 people along with their livestock. It spanned 18 stories beneath the surface, and offered its residents fresh flowing water, ventilation shafts, individual living quarters (apartments), shops, community rooms, a chapel, wells, tombs, arsenals and escape routes.

 
 

In late 2013, a housing construction project dug up another large underground city which may possibly rival Derinkuyu in size and features. Kitchens, wineries, chapels, oil presses, air shafts and water channels were all present in the multilevel complex, which is still being excavated and is yet unnamed. The exact size of the city is also unknown at this time.

The “City of the Gods” Metropolis

Giza

Could Egypt’s Giza Desert, home to a number of archeological wonders that have literally withstood the sands of time, be hiding a “buried treasure” of sorts beneath its ancient landscape? According to lore based on ancient writings, a massive underground complex that could have accommodated hundreds of thousands of people hides beneath the sands of the Giza Plateau. Though researchers began mapping the enigmatic “City of the Gods” back in 1978, it has yet to appear in any form other than speculation.

Ancient Burial Ground with Killer Acoustics

hal-saflieni-hypogeum-in-malta

The subterranean structure Hypogeum of Hal-Saflieni, located in Paola, Malta, and dating back to around 3,000 BC, likely served as a burial site. When construction workers accidentally unearthed the prehistoric underground temple in 1903, they discovered 7,000 skeletons with elongated skulls piled within the chambers. While the temple offers a number of underground rooms and chambers, it is the unique acoustic properties found within the ‘Oracle Chamber’ that astound experts around the world. When standing in a certain spot, male voices (in the 95 to 120 Hz range) can reverberate throughout the entire three-story complex. Even more bizarre, chanting at about 110 Hz frequency can transform the entire complex into a weird trance-inducing room that some studies suggest may stimulate creativity in the human brain.

How to Survive a Nuclear Bomb

Cheyenne-North-Portal_large

Located in the scenic city of Colorado Springs, CO, Cheyenne Mountain Complex is a nuclear bunker complex built during the height of Cold War paranoia and home to the military institution of NORAD. Construction on the complex, which spans five acres, took place from 1961 to 1965. It was designed to sustain an EMP as well as deflect a 30 megaton nuclear explosion. A 25-ton blast door guards the main entrance. A self-sustaining facility with its own power plant, heating and cooling system, and water supply, it also boasts a number of amenities such as a medical facility, store, cafeteria and fitness centers. (Ironically, it’s located fairly close to the Denver International Airport, which some conspiracy theorists suggest secretly hides a massive underground military facility).

Left: Burlington - Right: Dixia Cheng
Left: Burlington – Right: Dixia Cheng

Other “infamous” nuclear bunkers include Dixia Cheng, an expansive network dubbed the “Underground Great Wall” that runs beneath the city of Beijing, China, built to protect the city from a Soviet invasion, and the Central Government War Headquarters, a.k.a. Burlington, in Wiltshire, Britain, a massive underground complex built during the Cold War to shelter up to 4,000 people in complete isolation from the outside world for up to three months.

 

Share This:

Subscribe to Receive New Blog Post Notifications

Leave a Reply

Your email address will not be published. Required fields are marked *