Eel Drilling LLC is committed to providing safe and affordable Horizontal Directional Drilling (HDD) and boring for the trenchless installation of underground infrastructure. We take great pride in the service we deliver and dedicate ourselves to the safety of our employees, our clients, the general public and the environment.

We are HDD specialists with proven experience across the United States. Eel Drilling bores anything from 1.25-inch to 30-inch diameter with bore lengths that range from 20 feet to 1,300 feet (a quarter mile).

Originally founded as Elite Drilling in 2012, Eel Drilling is family owned.


Eel Drilling’s crews are efficient with bores from 1.25-inch to 30-inch diameter with bore lengths that range from 20 feet to 1,300 feet (a quarter mile). We can pull in single or multiple products of the same or varying sizes and work with all types of material including steel pipe, plastic HDPE, PVC, direct bury cable and tracer wire.

Eel Drilling emphasizes completing projects safely, within budget and on-time. We work to minimize surface disruptions above the ground, saving costly repairs on asphalt, concrete, and landscaping. Our teams are capable of horizontal directional drilling, hydro-excavation, site restoration and GIS data collection and submittal.

Our HDD underground and trenchless services are provided to many industries, including:

  • Oil and Natural Gas Exploration, Development and Transportation
  • Electric Power and Gas for Transmission, Industrial, Commercial, and Residential Power
  • Frac Water and Carbon Dioxide (CO2) Pipelines
  • Telecommunications, wire and Fiber Optic
  • Potable Water, Sanitary Sewer, Storm Sewer, Irrigation Water, and High-Pressure Sewage Pumping
  • Renewable Energy; Wind, Solar and Geothermal Power
  • Geothermal Heating and Cooling
  • Environmental Remediation
  • De-watering
  • Military, Government and Secure Facilities

We also provide many additional services including:

  • Hydro-vac services to safely expose existing buried utilities (aka Pot Holing and Test Holes)
  • Hydro-trenching where underground utilities are very dense and traditional trenching techniques are not safe
  • Buried utility locating with electronic utility locators
  • Plan and profile bore design and electronic computer aided drafting and design (CADD)
  • Geographic Information System (GIS) mapping using Global Satellite Navigation Systems (GNSS) hardware and software with full RTK (Real-Time Kinematic) rover workflow and the Atlas L-Band correction service for a geospatial solution with survey-grade accuracy.
  • GIS data collection and submission using precision underground utility mobile mapping hardware and software (such as Prostar’s PointMan) for jurisdictions such as the Colorado Department of Transportation (CDOT).
  • Excavation and construction site restoration.

Eel Drilling’s fleet of equipment includes many sizes of machines, including rigs that have thrust and pulling power up to 40,000 pounds. Drilling operation support equipment includes trailer mounted and large semi-truck mounted hydrovacs. Excavation equipment includes rubber tracked equipment for working on soft and hard surfaces as well as over the road hauling equipment. With Eel Drilling’s machines and expertise, we are capable of boring in virtually any ground condition.

What is Horizontal Directional Drilling

Directional boring, also referred to as Horizontal Directional Drilling (HDD), is a minimal impact trenchless method of installing underground utilities such as pipe, conduit, or cables in a relatively shallow arc or radius along a prescribed underground path using a surface-launched drilling rig. Directional Boring/HDD offers significant environmental advantages over traditional cut and cover pipeline/utility installations. The technique is routinely used when conventional trenching or excavating is not practical or when minimal surface disturbance is required.

HDD is often the only practical solution for the installation of utilities and pipelines beneath rivers, highways, railroads, roads and environmentally sensitive areas, or areas where the topography or site conditions along a proposed alignment conflicts with conventional cut and cover installation practices.

HDD is suitable for a variety of soil conditions including clay, silt, sand, and rock. Problematic soil conditions include large grain content in the form of coarse gravel, cobbles, and boulders. Other subsurface conditions which can impact the feasibility of Directional Boring/HDD include excessive rock strength and abrasiveness, poor rock quality, and rock exhibiting karst features. To combat this, we use only the latest environmentally friendly and approved bore additives to ensure we can install customer conduit according to standards.

How Horizontal Directional Drilling Works

It all starts with a need for a connection from one point to another. It could be for a pipe to move fluids like water, sewage, oil, gas; or electricity for power or signal; or light via fiber optics for communications and data. Horizontal Directional Drilling (HDD) is a trenchless operation and is often utilized when minimal surface disturbance is required. It is more cost effective to bore under land scaping, concrete walks, driveways, asphalt roads, and the like then it is to cut a trench through those and then replace the damaged improvements. In some cases, like highways, interstates, railroads, streams, rivers and lakes, there is no other practical solution besides HDD.


  1. The need for a point-to-point underground connection is identified.
  2. Subsurface Utility Engineering (SUE) begins where alternative paths to route the connection are identified, and a path of least resistance is preliminarily chosen. Factors considered in identifying the path include availability of right-of-way or an easement, avoidance of other buried utilities and obstacles, etc. Sometimes the path of least resistance is not the most direct, or shortest route.
  3. The bore is preliminarily planned, and easements and permits are obtained. The planning includes data collection at a variety of Quality Levels (QL) with D being the lowest and A being the highest QL (as defined by ASCE CI 38-02).
a. Level D (QL-D)

Record Research/Data Collection: This level of data is derived from records research or oral history. It gives an
idea of how congested the area may be but does not provide specific and accurate detail for utility locations.

b. Level C (QL-C)

Visible Surface Feature Utility Survey: Level C data maps out utility surface features by surveying the area and
plotting what’s visible above ground. Using these features along with utility records, you can then map underground utilities.

c. Level B (QL-B)

Utility Designation: This data level is collected using electromagnetic induction utility locators and geophysical
equipment operated from the surface to designate the locations of underground utilities. Utilities are marked out and
recorded on a map with plan documents.

d. Level A (QL-A)

Underground Utility Locating (Test Hole): This is the highest confidence level of utility locating. Each test hole allows for visual confirmation that guarantees the utility’s horizontal and vertical mapping location. To accomplish QL-A, Eel Drilling uses non-destructive vacuum excavation to expose, measure, and map utilities safely.

4. Underground utilities are located using electromagnetic induction and other tools and marked with paint on the ground. On public rights-of-way, 811 is utilized. For private ground, a utility locator is utilized along with owner information.

5. Marked utilities are exposed using non-destructive vacuum excavation and depths are verified. AKA potholing, test holes and daylighting. Hydro excavation equipment needs a vacuum source. A fan system can move air in huge amounts and allows for faster excavations while providing the operators an easier method to control and operate. This system cuts through the soil and breaks it up while the vacuum then lifts the slurry from the excavation area and transfers it to a debris tank. It allows for less congestion and traffic in the excavation area because the equipment can be positioned at a distance.

6. The running line of the bore is field verified taking the limitations on turning (both horizontal and vertical) into consideration. Small adjustments are made so all identified subsurface infrastructure is avoided.

7. The pilot hole is bored. A pilot hole is first drilled along the predetermined path:7a. The electronics are calibrated. The beacon that is located underground in the drill head transmits location, steering and slope information to the electronic locator directly above on the ground surface which in turn transmits the information back to the drill rig.

7b. Drilling mud is mixed for the soil conditions. The drill mud cools the drill head and electronics, carries the cuttings out of the hole, and holds the hole open until the conduit can be pulled into the hole. The drill mud is primarily water with environmentally friendly additives such as bentonite clay and soap used to aide the drilling process.

7c. The cuttings and drill mud are vacuumed up and hauled to a site where the water evaporates away, and the dirt can be used as fill for other projects. The cuttings are the same ground surface material as digging a trench for the utilities or a foundation for a building. HDD cuttings are not like oil and gas cuttings from deep underground that may contain petroleum and other compounds that may be hazardous.

7d. The drill is steered by the drill operator getting direction from the drill locator and the electronics. Steering is achieved by pushing or carving the off-center drill bit up, down, left or right. When the operator wants the drill to go straight, they continuously turn the off-center drill bit as it is pushed forward. Often the drill locator is not within sight of the drill operator and radio communication is used.

8. Reaming. The pilot hole then may be enlarged in single or multiple steps (reaming passes) to accommodate the pullback of the carrier pipe into the enlarged hole. For smaller pipe from 1.25” to 3”, reaming may not be necessary.

9. The conduit(s) are then pulled through the reamed hole.

10. The conduit is terminated, and the site is restored.

Eel Drilling Safety

Health, safety and environment (HSE) are top priorities for Eel Drilling. Our training programs include operator training, mentoring, first aid, industry specific, environmental, weekly safety meetings, and much more. Environmental training includes preparing for and minimizing hydraulic fracture inadvertent returns (HFIR) during construction. We believe that safe, unobtrusive underground construction is essential to the future of our nation’s infrastructure. Eel Drilling’s crews are experts in a wide variety of trenchless methods to construct pipelines and utilities in places where open trench installations are not desirable or are not feasible.

All Eel Drilling personnel receive regular training to obtain and hone their knowledge, skills and equipment to help ensure a safe workplace. Every employee has Stop Work Authority, encouraging all possible eyes to be on the lookout and prevent incidents and accidents. Every employee is trained and is responsible for hazard identification, accident prevention and is empowered to act in the interest of safety and the environment.

Safety is for our team, our clients, the general public and the environment. We want everyone to be able to fully enjoy all the utilities and life’s conveniences that our teams work so hard to install.


Eel Drilling goes to great lengths to hire the best. It takes a team effort to be an industry leader, and we’re serious about hiring the best and the safest that the business has to offer. We are always interested in hearing from potential employees who are looking to advance themselves and join a company to learn the industry from the ground up.

Eel Drilling offers a competitive compensation and benefits package and a positive work environment for employees.

Current openings:

  • CDL Driver
  • Locator
  • Operator
  • Laborer
  • Hydrovac / Potholing
  • Foreman
  • Utility Notification Coordinator

To apply, please complete form:

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Corporate Office:

Phone #: 303.529.2902
Eel Drilling LLC
6537 Bear Ridge Way
Golden, CO 80403

Rick Gillan
[email protected]

Drew Gillan
[email protected]