If you're planning any excavation in Indiana, you've heard the phrase "Call 811 before you dig." It's the law, and it's a critical first step. But 811 and private utility locating services aren't the same thing, and confusing the two is one of the most expensive mistakes a contractor can make. This post breaks down exactly what 811 covers, what it doesn't, and when you need to hire a private locator.
What Is 811 (Call Before You Dig)?
811 is the national "Call Before You Dig" number operated through state notification centers. In Indiana, the program is administered by Indiana 811. When you call or submit a ticket online at least two business days before excavation, member utility companies are legally required to send locators to mark the approximate location of their underground infrastructure in your work area.
The service is free to the caller, and Indiana law (IC 8-1-26) makes it mandatory before any excavation. If you dig and hit an unmarked 811-member utility without having called first, you're liable. If you call and dig where marks say it's clear, the utility owner shares liability.
That's the short version. Here's where it gets complicated.
What 811 Does NOT Mark
811 only marks utilities owned by member companies that are located in the public right-of-way. That leaves out a substantial portion of the underground infrastructure on most developed properties. Specifically, 811 does not mark:
- Private water service laterals: the pipe running from the public main to your building
- Private sewer laterals: the pipe running from the building to the public sewer
- Irrigation systems: any underground sprinkler or drip feed infrastructure
- Site lighting feeds: electrical conduit serving parking lot lights, bollards, signage
- Private fiber and low-voltage conduit: security cameras, data networks, telephone, access control
- Abandoned utilities: decommissioned pipes and conduits that are no longer active but still physically present
- Non-member infrastructure: utilities owned by entities that aren't enrolled in Indiana 811
- Anything on private property beyond the right-of-way: once you cross the property line, 811's coverage becomes unreliable or stops entirely
On a typical commercial or industrial property, these private utilities often outnumber the 811-marked lines. A warehouse complex, a retail strip center, a hospital campus: the infrastructure running under the surface is dense, layered, and largely invisible to 811.
What Private Utility Locating Covers
Private utility locating fills the gap. A professional locator uses two core technologies to find everything 811 misses:
Electromagnetic (EM) Locating
EM locating applies a signal to a metallic utility (a pipe, a conduit, a wire) and then traces that signal with a receiver. It's highly accurate for any conductive infrastructure: copper water mains, steel gas lines, direct-buried electrical conduit, metallic communication cables. Most of the lines 811 marks are also metallic, but private locators can apply EM to private infrastructure that 811 locators never touch.
Ground Penetrating Radar (GPR)
EM locating can't find non-metallic utilities: PVC pipe, HDPE, fiber conduit, concrete structures. That's where Ground Penetrating Radar comes in. GPR transmits energy pulses into the ground and records the reflections from subsurface features. It can detect plastic pipe, concrete manholes, voids, and other non-conductive infrastructure that would be completely invisible to EM locating. Used together, EM and GPR give you a comprehensive picture of what's underground.
Accuracy: 811 Marks vs. Private Locating
Even where 811 and private locating cover the same utility, the accuracy standards are very different.
| Metric | 811 Locating | Professional Private Locating |
|---|---|---|
| Horizontal accuracy | ±18 inches (industry standard) | ±2 inches |
| Depth accuracy | Not provided | ±1 inch |
| Depth information | No | Yes |
The APWA color-coded paint marks 811 leaves on the ground represent an approximate center line. The actual utility could be anywhere within that 18-inch tolerance zone, and that tolerance doesn't account for depth at all. For hand-digging around known utilities, that's manageable. For mechanical excavation, core drilling, or any tight-tolerance work, that uncertainty is a liability.
Professional locators achieve ±2 inches horizontal and ±1 inch depth using calibrated equipment, field verification techniques, and experience. That precision is what allows excavation crews to work confidently with small clearances.
Deliverables: Paint vs. Documentation
Another significant difference is what you receive at the end of the job.
811: Paint marks on the ground. They fade in days to weeks, can be obscured by rain or traffic, and leave no permanent record. If work is delayed, you may need to request re-marks.
Private utility locating: A professional locating firm delivers:
- Digital field maps showing all located utilities with GPS coordinates
- CAD files compatible with your engineering software
- Written reports documenting methodology, findings, and any areas of uncertainty
- Depth readings for each utility
- Permanent record-keeping for project files and future reference
For projects that require permitting, bonding, or owner-furnished documentation, 811 marks simply aren't sufficient. A signed, stamped utility map from a professional locator meets the documentation standard that engineering firms, general contractors, and project owners require.
Do You Need Both?
On almost every commercial project: yes. Here's the practical workflow:
- Call 811 at least two business days before excavation; this is legally required regardless of what else you do.
- Wait for all 811 member utilities to be marked.
- Hire a private locator to locate everything 811 didn't mark and to verify accuracy-critical areas on 811-marked lines.
811 establishes the baseline legal compliance. Private utility locating provides the operational intelligence you actually need to excavate safely. They're complementary, not competing.
On residential projects, the calculus shifts. A simple fence post job on a property with minimal site development might only need 811. But even there, if the yard has an irrigation system, landscape lighting, or a private gas feed to an outbuilding, 811 won't find them.
When Private Locating Is Non-Negotiable
Certain project types always warrant private utility locating regardless of what 811 shows:
- Commercial and industrial demolition: you need to know about everything under the slab and in the yard before swinging any equipment
- Directional boring: boring through an 18-inch uncertainty zone without depth data is an avoidable risk
- Core drilling in existing slabs: GPR to locate rebar, post-tension cables, and embedded conduit before the drill goes in
- Sites with significant prior development history: older properties accumulate decades of utility infrastructure, including abandoned systems that no one has records for
- Any project where a strike has serious consequences: high-voltage lines, gas transmission infrastructure, or utilities adjacent to occupied structures
Frequently Asked Questions
Is 811 locating really free?
Yes. The cost is built into utility rates. There is no charge to submit a ticket or to have a locator come out. The locators who respond are employees or contractors of the member utilities.
How long does 811 take in Indiana?
Indiana law requires member utilities to mark within two full business days of your ticket submission, excluding weekends and holidays. In practice, most marks appear within that window. Emergency tickets can be submitted for same-day response.
Can a private locator replace 811?
No. Indiana law requires you to call 811 regardless of what other locating you arrange. Private locating does not satisfy the legal notification requirement.
What if 811 marks show clear but my private locator finds something?
This happens regularly on developed properties. It means 811 either had nothing to mark (no member utilities in that area) or didn't mark private infrastructure, which is exactly why private locating exists. Document the privately-located utilities, adjust your excavation plan, and proceed.
How much does private utility locating cost compared to hitting a line?
A utility strike can cost anywhere from a few thousand dollars for a minor repair to hundreds of thousands for a major gas or high-voltage incident, not counting delays, liability, and potential injury. Professional locating on a typical commercial site is a fraction of that risk exposure.
The Bottom Line
Call 811 first, every time: it's the law and it protects you. Then call a private locator for everything 811 doesn't cover. On any commercial or industrial site, that's most of what's actually underground.
If you're planning excavation in Indiana and want to know exactly what's under your site before the first bucket goes in, contact Midwest Site Recon to discuss your project. We provide EM locating and Ground Penetrating Radar services with digital deliverables built for project documentation.