Borehole Clearing: Utility Locating for Environmental Drilling in Colorado

The Risks of Environmental and Geotechnical Drilling

In Colorado’s booming commercial real estate and infrastructure sectors, environmental assessments and geotechnical engineering are mandatory first steps for new development. Engineers must drill deep into the earth to extract soil samples, test groundwater, or install environmental monitoring wells.

However, plunging a heavy-duty auger or direct-push drill rig (like a Geoprobe) 20 to 50 feet into the ground comes with an immense risk. If the drill rig strikes a high-voltage electrical duct bank, a pressurized gas main, or a fiber optic bundle, it can cause lethal injuries to the drill crew, massive environmental contamination, and hundreds of thousands of dollars in damages.

To mitigate this risk, environmental and geotechnical firms require a specialized service before they ever fire up a drill rig: Borehole Clearing.

What is Borehole Clearing?

Borehole clearing (sometimes called drill site clearance) is the precise process of utilizing Ground Penetrating Radar (GPR) and Electromagnetic (EM) locating equipment to scan a specific, localized area before drilling begins.

Instead of just mapping out the general trajectory of utilities across an entire property, a utility locator will hyper-focus on the exact proposed drill locations.

Typically, the engineer will mark their desired drilling spot with a stake or a painted dot. The locator will then scan a predetermined radius around that point (usually a 10x10 foot or 20x20 foot square). If a utility is detected crossing through that safety square, the locator will map it out, and the engineer can safely relocate their borehole a few feet away.

Why 811 is Insufficient for Drillers

While geotechnical firms must call 811 to notify public utilities of their intent to drill, 811 is simply not enough to ensure a safe borehole for several reasons:

1. The Private Property Blind Spot: Environmental drilling often occurs on commercial properties, gas stations, or old industrial sites filled with private, undocumented utilities (like underground storage tanks and private product lines). 811 will not mark these.
2. Tolerance Zones: 811 marks provide a “tolerance zone” (usually 18 to 24 inches on either side of the paint mark). This is a general guideline, not a pinpoint location. Drillers need exact, highly accurate depth and location data that public locators are not designed to provide.
3. Non-Metallic Targets: 811 relies heavily on electromagnetic locators, which cannot find PVC pipes, fiberglass tanks, or concrete vaults.

The JLP Tech Approach to Borehole Clearance

At JLP Tech, we partner with environmental consultants, geotechnical engineers, and drilling contractors across the Denver metro area and throughout Colorado to provide comprehensive drill site clearance.

We utilize a multi-technology approach:

• EM Locators: To trace known conductive utilities, lighting wires, and private power feeds.
• Ground Penetrating Radar (GPR): To sweep the boring location for unknown anomalies, non-metallic pipes, and underground storage tanks (USTs).

By thoroughly clearing every single borehole location, we ensure your field crews can drill with absolute confidence, keeping your environmental assessments on schedule and your personnel perfectly safe.