Call 811 for Utility Location
Before any digging begins, you must call 811 to have underground utilities marked. This free, federally-mandated service prevents catastrophic accidents and is legally required in all 50 states.
Quick Summary
Time needed
10 min call + 2-3 day wait
Cost
FREE
Valid for
14-28 days (varies by state)
Why This Step Matters
Every year, underground utilities are hit every 6 minutes in the United States. Hitting a gas line can cause explosions. Hitting an electrical line can be fatal. Hitting a fiber optic cable can result in $50,000+ in repair costs. A simple phone call prevents all of this.
Legal Requirement
Digging without calling 811 is illegal. If you hit a utility line and didn't call, you're liable for all repair costs, injuries, and fines. These can easily exceed $100,000.
How to Request Utility Marking
Call 811 or Submit Online
Dial 811 from any phone, or visit call811.com to submit a request online. Most states also have their own one-call center websites with online request forms.
When to call: Most states require 2-3 business days notice before digging. Call at least a week early to avoid project delays.
Provide Project Details
Be prepared to provide:
- Address: Your complete property address
- Dig location: Where on the property you'll be excavating
- Dig date: When excavation will begin
- Type of work: Foundation excavation for home addition
- Contact info: Your phone number for updates
Mark Your Dig Area with White Paint
Before utility locators arrive, outline your proposed excavation area using white paint, flags, or stakes. This shows them exactly where to mark and ensures they don't miss any areas you'll be digging.
Be generous: Mark an area larger than you think you need. Include access paths for equipment and any areas that might be disturbed.
Wait for Utility Locators
Each utility company will send a locator to mark their lines. This typically takes 2-3 business days. You'll receive a ticket number to track the request and verify all utilities have responded.
You don't need to be home: Locators just need access to your property. Make sure gates are unlocked and pets are contained.
Verify All Utilities Responded
Check your ticket status online or by calling 811. Every utility company must respond with either marks on your property or a "clear" (no utilities in area). Do not dig until all utilities have responded.
Utility Color Codes
Locators use a standardized color system. Here's what each color means:
| Color | Utility Type | Danger Level |
|---|---|---|
| Red | Electric power lines, cables | EXTREME |
| Yellow | Gas, oil, petroleum, steam | EXTREME |
| Orange | Communication, cable TV, fiber | HIGH (costly) |
| Blue | Potable water | MODERATE |
| Green | Sewer, storm drain | MODERATE |
| Purple | Reclaimed water, irrigation | LOW |
| Pink | Temporary survey marks | N/A |
| White | Proposed excavation (you mark this) | N/A |
What 811 Doesn't Mark
811 only marks public utility lines. You're responsible for locating:
Private Lines (Your Responsibility)
- • Propane tank lines
- • Septic system pipes
- • Well water lines
- • Private electric (from meter to house)
- • Irrigation/sprinkler systems
- • Invisible pet fences
How to Locate Private Lines
- • Hire a private utility locator ($100-$300)
- • Check records from when systems were installed
- • Use a metal detector for metal pipes
- • Probe carefully with a rod in sensitive areas
- • Ask your septic/propane company for maps
Important
If you have propane, a septic system, or a well, you MUST locate these private lines yourself. Hitting a propane line is just as dangerous as hitting a public gas line.
How Long Are Marks Valid?
Utility marks expire after a certain period. If you don't dig within this window, you must call 811 again.
Typical validity period
14-28 days
Varies by state
Response time
2-3 business days
Some states offer expedited service
Pro tip: If your excavation will take more than 2 weeks, re-mark halfway through. Paint fades and stakes get knocked over. Fresh marks prevent accidents.
Frequently Asked Questions
Is my contractor supposed to call 811, or do I?
Either can call, but verify who is responsible. Most contractors include this in their scope, but don't assume. If your contract says you're responsible for permits and site prep, you may need to call yourself.
What if a utility company doesn't respond in time?
Call 811 back and report the non-response. They'll escalate to the utility company. Do NOT dig until you have confirmation from all utilities, either marks on the ground or a "clear" response.
How accurate are the utility marks?
By law, marks are typically accurate within 18-24 inches of the actual line. Always hand-dig within 2 feet of any marks. Never use mechanical equipment within this "tolerance zone" until you've visually confirmed the line location.
What happens if we accidentally hit a utility?
Immediately evacuate the area and call 911 for gas or electrical hits. Then call the utility company's emergency number (usually on the 811 ticket). If you called 811 and followed proper procedures, you're generally not liable. If you didn't call, you're responsible for all damages.
Ready for the Next Step?
Once all utilities are marked and you've verified responses from every company, it's time to begin excavation for your foundation.