In Pennsylvania, the law is simple: before you put a shovel, auger, or backhoe into the ground, you have to call 811 (PA One Call) at least three business days ahead so buried utilities can be marked. The requirement to call PA 811 before you dig applies to everyone — homeowners planting a tree, contractors trenching for a foundation, utility crews replacing a pole. The service is free, the call takes a few minutes, and skipping it can cost you up to $50,000 in administrative fines on top of the repair bill for whatever line you hit.
Who Has to Call
The Underground Utility Line Protection Act (Act 287 of 1974, most recently amended by Act 127 of 2024) defines an “excavator” as anyone who performs excavation or demolition, whether for themselves or someone else.1Pennsylvania One Call System. Underground Utility Line Protection Law That sweeps in the homeowner setting a fence post, planting a shrub, or installing a mailbox. If powered equipment or explosives move earth, it counts.
Only a couple of narrow activities fall outside the rule. Agricultural tilling less than eighteen inches deep is exempt, and so is minor routine road maintenance under eighteen inches measured from the cartway or improved shoulder.1Pennsylvania One Call System. Underground Utility Line Protection Law Everything else triggers the call.
When to Call
You must notify PA One Call between three and ten business days before you plan to start work. The clock begins the business day after the system receives your request, and you cannot break ground before the third business day.1Pennsylvania One Call System. Underground Utility Line Protection Law Requests that come in on a Saturday, Sunday, or holiday are processed the following business day.
If you file the ticket and then stay off the site for more than two business days, you have to contact PA One Call again before resuming.2Pennsylvania One Call System. Frequently Asked Questions Marks fade, conditions change, and the law treats a cold work site as a new job.
How to Submit the Request
Two ways: dial 811 and talk to a representative, or use the PA One Call web portal and enter the details yourself with a digital map to confirm the location.3Pennsylvania 811. Pennsylvania 811 Excavators Either way, the system issues a serial number for each political subdivision your project touches. Keep that ticket number accessible at the work site.
Before you contact them, pull together the basics: county, municipality, exact street address, the type of work, and how deep you intend to dig. PA One Call wants a clearly bounded area with identifiable reference points, such as nearby landmarks or the specific portion of the property you’ll be disturbing.3Pennsylvania 811. Pennsylvania 811 Excavators When words won’t do the job, Act 287 tells you to pre-mark the dig area with white paint or white flags.1Pennsylvania One Call System. Underground Utility Line Protection Law White-lining tells locators exactly where to focus so they’re not marking the whole yard.
Waiting for Utility Responses
Once your request is in, utilities in the area are notified automatically. They have until the end of the second business day after PA One Call received the request to respond, or until the day before your scheduled start if you set a later date.4Pennsylvania Department of Labor and Industry. Underground Utility Line Protection Law Act 287 of 1974
You can track their replies through KARL (Know All Responses by Logging in), the automated response system on the PA One Call website or by phone. Each utility will either confirm the site has been marked, state there’s no conflict in the area, or ask for more time. Do not dig until every utility on your ticket has responded.
If a utility misses the deadline, you must renotify PA One Call about the unresponsive company. The facility owner then has two hours to communicate line locations directly to you and, if needed, come mark them. If three hours pass with still no sufficient information, you may proceed, but only with due care and inside the tolerance zone rules below.1Pennsylvania One Call System. Underground Utility Line Protection Law Silence is never a signal that nothing is buried.
Reading the Marks
Locators use the American Public Works Association uniform color code:5American Public Works Association. Uniform Color Code
- Red: electric power lines, cables, and lighting conduit
- Yellow: gas, oil, steam, and petroleum lines
- Orange: communication, alarm, and signal lines (phone, cable, fiber)
- Blue: potable water
- Green: sewers and storm drains
- Purple: reclaimed water, irrigation, and slurry lines
- Pink: temporary survey markings
- White: proposed excavation area (your pre-markings)
Knowing the colors matters once you start digging. Yellow paint and sudden resistance mean a gas line, not a water main, and that changes how carefully you proceed and who you call if something goes wrong.
Digging in the Tolerance Zone
Pennsylvania law defines the tolerance zone as the horizontal space within eighteen inches of the outside wall or edge of a marked line.1Pennsylvania One Call System. Underground Utility Line Protection Law Picture a thirty-six-inch corridor centered on the paint. The actual pipe or cable can be anywhere inside it.
Within that corridor, you have to use prudent techniques to find the line’s exact position before cutting through: hand-dug test holes, vacuum excavation, or similar careful methods.1Pennsylvania One Call System. Underground Utility Line Protection Law Mechanical equipment isn’t banned outright, but you have to verify the line’s precise location first. This is where most line strikes happen and where most violations get written.
What 811 Won’t Mark
PA One Call locators mark lines owned by utility companies, typically stopping at the meter or where the utility connects to private property. Customer-owned lines past that point are your responsibility: service lines running to the house, outdoor lighting wires, pool electrical connections, barbecue gas lines, invisible pet fences.6Pennsylvania One Call System. Homeowners If your dig site is anywhere near those, hire a private locating service. PA One Call keeps a list of them on its website. Private locators use electromagnetic and ground-penetrating radar equipment to trace what the public system won’t.
Emergency Digging
Act 287 defines an emergency as a sudden or unforeseen occurrence involving a clear and immediate danger to life, property, or the environment, including serious breaks or defects in a facility owner’s lines. In those situations the three-day window doesn’t apply. You can start immediately, but you still have to notify PA One Call as soon as possible, before, during, or after the work depending on the circumstances. Facility owners must respond as soon as practicable given the nature of the emergency.4Pennsylvania Department of Labor and Industry. Underground Utility Line Protection Law Act 287 of 1974 The exemption shortens the timeline; it doesn’t erase the duty to call.
If You Hit a Line
Stop work. Under Act 287 you must report any break, leak, dent, gouge, or damage to a facility owner’s line as soon as you find it, even damage that looks minor.1Pennsylvania One Call System. Underground Utility Line Protection Law A small nick on a gas pipe’s coating can corrode into a leak months later.
If the damage releases any flammable, toxic, or corrosive gas or liquid that endangers life, health, or property, call 911 and the facility owner immediately. The law also requires you to take reasonable measures to protect yourself, your crew, bystanders, and surrounding property until responders arrive and finish their assessment. Stay on site to help them handle the situation safely.1Pennsylvania One Call System. Underground Utility Line Protection Law
Within ten business days of any strike that causes personal injury or property damage to anyone other than the excavator or the affected facility owner, file an incident report with the Pennsylvania Department of Labor and Industry.1Pennsylvania One Call System. Underground Utility Line Protection Law
Who Pays When a Line Gets Hit
An excavator who followed Act 287 and was not otherwise negligent is not liable for damage to a utility’s lines.1Pennsylvania One Call System. Underground Utility Line Protection Law Compliance is your shield. You called 811, waited the required time, checked KARL, used prudent techniques in the tolerance zone, and still hit something: the facility owner carries the cost.
When fault is shared — you were negligent but the utility also mismarked or failed to mark — repair costs get split in proportion to each party’s contribution.1Pennsylvania One Call System. Underground Utility Line Protection Law If the marks were right and you dug through them anyway, you pay the full repair bill. A single gas main repair can run tens of thousands of dollars, before the utility pursues its service-interruption losses.
Fines for Not Calling
The Pennsylvania Public Utility Commission enforces Act 287 and can issue warnings, compliance orders, or administrative fines. The structure has two tiers:1Pennsylvania One Call System. Underground Utility Line Protection Law
- Standard violation: up to $2,500 per violation.
- Violation causing injury, death, or property damage of $25,000 or more: up to $50,000 per violation.
Unpaid fines accrue an extra $100 per day, capped at $5,000. The commission can also require completion of a damage prevention educational program within sixty days; missing that deadline triggers another $100-per-day penalty, again capped at $5,000.1Pennsylvania One Call System. Underground Utility Line Protection Law These administrative penalties sit on top of the civil liability for the physical damage, which is usually the larger number.