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Our Underground Services

Professional excavation, directional drilling, and utility services for Denver, Colorado. We deliver precision, safety, and excellence on every project.

Advanced Equipment
Licensed & Insured
24/7 Emergency
Expert Team

Directional Drilling

Our directional drilling services provide a non-invasive solution for installing underground utilities without disturbing the surface. Perfect for crossing under roads, buildings, and landscaped areas.

  • Minimal surface disruption
  • Precise underground navigation
  • Cost-effective installation
  • Utility line installation (water, gas, electric, fiber)
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July 1, 2025 - Stralsund-Germany: Small horizontal drilling machine with drill by start pit at roundabout corner, orange and white cables, sand heaps, fences and distant roadworks.
A mini excavator is working on a construction site.

Excavation

Professional excavation services for residential, commercial, and industrial projects. From site preparation to foundation work, we handle projects of all sizes with precision and efficiency.

  • Site preparation and grading
  • Foundation excavation
  • Utility trenching
  • Land clearing and demolition
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Trenching

Expert trenching services for utility installation, drainage systems, and infrastructure projects. We use modern equipment to create precise trenches while maintaining safety standards.

  • Utility line trenching
  • Drainage and irrigation systems
  • Precise depth and width control
  • Safe excavation practices
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Installation of underground electric cable in the city to the restaurant
Sewer repair. Pumping waste from hatch. Open hatch. Worker controls air supply. Sewerage accident.

Utility Potholing

Safe and accurate utility locating through hydro excavation. Our potholing services help identify and expose underground utilities before excavation, preventing costly damages and project delays.

  • Precise utility location verification
  • Non-destructive excavation
  • Damage prevention
  • Safe for all utility types
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Hydrovac Services

State-of-the-art hydro excavation services using high-pressure water and vacuum technology. Perfect for sensitive excavation around existing utilities and in challenging conditions.

  • Non-mechanical excavation
  • Precision digging in tight spaces
  • All-weather capability
  • Minimal environmental impact
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Hydrovac Services excavation equipment

Why Choose Onmark LLC?

Experience the difference of working with Denver's premier underground services contractor

Advanced Equipment

State-of-the-art machinery and technology for efficient, precise underground work.

Expert Team

Highly trained professionals with 25+ years of combined industry experience.

Safety First

Unwavering commitment to safety standards protecting your property and our team.

Licensed & Insured

Fully licensed, bonded, and insured for complete peace of mind on every project.

24/7 Availability

Emergency services available around the clock for your urgent underground needs.

Competitive Pricing

Fair, transparent pricing with detailed quotes and no hidden fees or surprises.

Ready to Get Started?

Contact us today to discuss your underground services project. Our team is ready to bring your vision to life with precision and professionalism.

25+
Years Experience
1000+
Projects Complete
100%
Licensed & Insured
24/7
Emergency Service
Home Services

Our Underground Services

Comprehensive underground construction solutions for Denver and surrounding areas. From directional drilling to hydrovac services, we deliver precision and excellence on every project.

Full Range of Services
5 Core Specialties
July 1, 2025 - Stralsund-Germany: Small horizontal drilling machine with drill by start pit at roundabout corner, orange and white cables, sand heaps, fences and distant roadworks.

Directional Drilling

Our advanced horizontal directional drilling (HDD) technology allows for precise underground installation of utilities without surface disruption. Perfect for crossing under roads, rivers, and existing structures with minimal environmental impact.

  • Minimal surface disruption
  • Precision underground navigation
  • Cost-effective utility installation
A mini excavator is working on a construction site.

Excavation

Professional excavation services for commercial and residential projects. Our experienced team handles everything from site preparation to foundation digging with precision and efficiency using state-of-the-art equipment.

  • Site preparation & grading
  • Foundation excavation
  • Underground utility access
Trencher machine digging a trench in gravel, with rotating blade and moving chain visible.

Trenching

Expert trenching services for utility line installation, drainage systems, and infrastructure projects. We create precise trenches of any depth or length while maintaining safety and efficiency standards throughout the process.

  • Utility line installation
  • Drainage system trenches
  • Custom depth & width options
Sewer repair. Pumping waste from hatch. Open hatch. Worker controls air supply. Sewerage accident.

Utility Potholing

Safe and accurate utility location services using advanced potholing techniques. We expose underground utilities to verify their exact location, depth, and condition before any excavation work begins, preventing costly damages.

  • Precise utility location
  • Prevent utility damage
  • Non-destructive verification
A hydro-vac sewer cleaning truck removes debris from an underground pipeline through an open manhole, with safety cones placed on a quiet forest road

Hydrovac Services

State-of-the-art hydrovac excavation services that use pressurized water and vacuum technology for safe, precise digging. This non-destructive method is perfect for sensitive areas around existing utilities, underground infrastructure, and tight spaces.

  • Non-destructive excavation
  • Safe around existing utilities
  • Precise soil removal
  • Environmentally friendly
Technician performing maintenance on a fiber optic cabinet to ensure network quality for customers

Fiber Optic Pulls

Expert fiber optic cable installation and pulling services for high-speed network infrastructure and telecommunications projects. Professional handling ensures optimal signal quality.

  • High-speed network installation
  • Telecommunications infrastructure
  • Professional cable handling

Why Choose Our Services?

When you partner with Onmark LLC, you get more than just underground services—you get peace of mind.

Licensed & Insured

Fully licensed, bonded, and insured for your complete protection and peace of mind on every project.

Expert Team

25+ years of experience with highly trained professionals who deliver quality results on every job.

Advanced Equipment

State-of-the-art machinery and technology for efficient, precise, and safe project execution.

Safety First

Unwavering commitment to safety standards, protecting your property and our team on every project.

24/7 Emergency Service

Round-the-clock availability for urgent underground service needs. We're here when you need us.

Trusted Partner

Over 1000+ successful projects completed with transparent pricing and reliable service delivery.

Ready to Get Started?

Contact us today for a free consultation. Let's discuss how our underground services can bring your project to life.

25+
Years Experience
1000+
Projects Completed
5
Core Services
24/7
Emergency Support