How States Protect Pipelines from Excavation Damage

Kristy Hartman and Daniel Shea 9/22/2021

More than 2.6 million miles of pipelines crisscross the United States, with most of them buried underground. Every year, they deliver trillions of cubic feet of natural gas and billions of barrels of crude oil and other petroleum products necessary for electricity generation, transportation, and heating and cooling. 

These arteries of the nation’s energy infrastructure stretch far and wide, and the ubiquitous nature of pipelines means that, without proper planning, any construction project that breaks ground risks damaging existing underground infrastructure. For natural gas and oil pipelines, that can also mean the potential for significant damage to individuals, property and the local economy.

Excavation damage is among the primary causes of pipeline damage. Only corrosion and equipment failure account for more incidents, according to the U.S. Department of Transportation’s Pipeline and Hazardous Materials Safety Administration (PHMSA).

The interactive map below has been designed to allow users to compare various aspects of one-call laws across the country. Select categories using the tabs in the column on the right.

Locators of underground facilities must complete a training program that meets the minimum training guidelines and practices of the Common Ground Alliance current Best Practices. Only a qualified person shall be employed to locate underground facilities.
Certain operators must employ at least two technically qualified individuals whose job is dedicated to locating underground facilities.
New Hampshire
Locators of underground facilities must be trained in accordance with the National Utility Locating Contractors Association standards.
North Carolina
Locators of underground facilities must be trained, with the training documented. All excavators, operators and locators has a duty to provide education and training to employees in order to competently and safely perform their work.
Locators of underground facilities must be trained using industry standards and practices no less stringent than the National Utility Locating Contractors Association’s locator training standards. Each locator’s training must be documented.
Alabama: Attorney general or district attorney Arizona: A building codes official, unless it’s a public utility or municipal corporation Arkansas: Attorney general, county prosecutor or city attorney California: Attorney general, district attorney or local or state agency that issued the excavation permit Colorado: Attorney general or district attorney Connecticut Department of Energy and Environmental Protection or the Connecticut Public Utilities Regulatory Authority Delaware: Attorney general DC: Corporation Counsel of the District of Columbia Florida: Any local or state law enforcement officer, government code inspector or code enforcement officer Georgia Public Service Commission Hawaii Public Utilities Commission Idaho: Prosecuting attorney in the county where damage occurred Illinois Commerce Commission Indiana Utility Regulatory Commission Iowa: Attorney general Kansas State Corporation Commission Louisiana Department of Public Safety and Corrections or any local law enforcement agency Maine Public Utilities Commission Maryland Underground Facilities Damage Prevention Authority Massachusetts Department of Telecommunications and Energy or the Massachusetts Department of Public Utilities Michigan Public Service Commission Minnesota Department of Public Safety’s Office of Pipeline Safety Mississippi Underground Facilities Damage Prevention Board Missouri: Attorney general or prosecuting attorney Nebraska: Attorney general or prosecuting attorney Nevada: Public Utilities Commission of Nevada New Hampshire Public Utilities Commission New Jersey Board of Public Utilities New Mexico Public Regulation Commission New York Public Service Commission or the New York Department of Public Service North Carolina Utilities Commission North Dakota: State attorney Ohio Public Utilities Commission Oklahoma Corporation Commission Oregon Public Utilities Commission Pennsylvania Department of Labor, in consultation with the attorney general or another prosecuting attorney Rhode Island Division of Public Utilities South Carolina: Attorney general, at the request of injured parties South Dakota Statewide One-Call Notification Board Tennessee Underground Utility Damage Prevention Enforcement Board Texas Railroad Commission Utah: Attorney general Vermont Public Service Board Virginia State Corporation Commission Washington Utilities and Transportation Commission and the attorney general Wisconsin: Attorney general, at the request of the Wisconsin Public Service Commission Wyoming: Attorney general, district attorney, county attorney, the one-call notification center, an aggrieved party, an operator or an excavator Montana: Enforcement agency not identified Alaska: Enforcement agency not identified Kentucky: Enforcement agency not identified West Virginia: Enforcement agency not identified

State Excavation Damage Prevention Laws by State

Welcome to NCSL’s Interactive Guide to State One-Call Laws. We have designed this map to serve as a comprehensive and intuitive resource to allow users to compare and contrast various aspects of One-Call Laws across the country. The elements touched on include communication requirements, damage notification requirements, minimum standards and special digging requirements, along with information on state enforcement programs.

Excavator Notice

Excavators must notify a one-call center at least:

  • five days prior to the start of excavation
  • three days prior to the start of excavation
  • two days prior to the start of excavation

While the timeline for excavator notification is not specified in statute, the law is written in a way that requires excavators to work within the timeline outlined for operators by default.

Operator Response

Operators must mark underground facilities within:

  • five days of receiving notice
  • four days of receiving notice
  • three days of receiving notice
  • two days of receiving notice

While the timeline for operators to mark facilities or respond to excavators is not specified in statute, the law is written in a way that requires operators to work within the timeline outlined for excavator notice by default.

Positive Response

Marking underground facilities constitutes positive response, but operators must also communicate to excavators if no underground facilities exist

Marking underground facilities constitutes positive response

Damage Notification

Excavator must notify:

  • both the operator and One-Call Center
  • the operator
  • a One-Call Center

HAZMAT Release

Excavator must call 911 if hazardous materials are released

Minimum Standards/Training

Minimum standards for locator qualifications established

Mouse over the states in green to view requirements for locators.

Tolerance Zone

  • 48 inches
  • 30 inches
  • 24 inches
  • 18 inches

Special Digging Requirements Within Tolerance Zone

Excavators must resort to hand-digging or employ other special excavation methods when operating wihin the tolerance zone.

Mandatory Reporting

Excavators must report any damage to underground facilities to a state entity or department

Enforcement Authority

Mouse over the map to view more information on each state's enforcement authority.

State agency created specifically to enforce damage prevention laws

State agency, such as public utilities commission

State or local prosecutor


Enforcement agency not specified

Mandatory Reporting

  • Maximum of $100,000
  • Maximums between $25,000 and $50,000
  • Maximums between $10,000 and $24,999
  • Maximums up to $9,999

From 2005 through 2016, there were 875 reported major pipeline incidents caused by excavation damage. These resulted in 40 fatalities, 166 injuries requiring hospitalization, and more than $322 million in property damage. However, the annual number of excavation-related incidents is dropping—from nearly 100 incidents in 2005, to an annual average of just over 60 incidents in more recent years. Despite this downward trend, excavation damage continues to threaten pipeline safety and integrity. According to PHMSA, gas utilities experienced 85,896 leaks caused by excavation damage in 2016.

Every state has its own excavation damage prevention law—often referred to as a “One-Call Law” or “811 Law”—that establishes requirements for both excavators and operators of underground infrastructure, along with structural and procedural requirements on the part of the state. However, the specific requirements and the level of enforcement of those laws can vary considerably from state to state. 

In order to ensure that state excavation damage prevention laws are working effectively to further reduce the number of excavation damage incidents, Congress granted PHMSA limited authority to bring enforcement action against excavators who cause pipeline damage due to violations of the law. The Pipeline Inspection, Protection, Enforcement and Safety (PIPES) Act of 2006 gave PHMSA authority to conduct administrative civil enforcement proceedings against excavators, but only in states deemed to have inadequate excavation damage enforcement programs.

Based on the congressional mandate, PHMSA undertook an effort to conduct reviews of all state programs to determine if states are adequately enforcing their damage prevention laws.

PHMSA issued a final rule (49 CFR Parts 196 and 198) in July 2015 that established the criteria for PHMSA to apply in evaluating the effectiveness of states in enforcing their damage prevention laws.

The criteria include:

  • Does the state have authority to enforce its law using civil penalties and other sanctions?
  • Has the state designated a state agency or other body as responsible for enforcement of the law?
  • Is the state assessing civil penalties and other sanctions for violations at levels sufficient to deter violation of the law? Does the state make that information public and accessible?
  • Over the past year, has the state assessed civil penalties or other sanctions for violations of the law?
  • Does the enforcement authority have a reliable mechanism to learn about excavation damage?
  • Does the state employ investigation practices adequate to enforce the law?
  • At a minimum, does the state require that excavators not engage in excavation activity without first using a one-call center to establish the location of underground infrastructure, and does it prohibit excavators from excavating in disregard of the markings of underground infrastructure?
  • Does the law require that an excavator who damages underground infrastructure contact the operator at the earliest practical moment?
  • If the law results in the release of natural gas or other hazardous materials, does the law require that excavators call 911 or another emergency number?
  • Does the state limit exemptions from the damage prevention law?

Following its evaluation of state programs, PHMSA began notifying states as to the adequacy of their programs. For states deemed to have inadequate enforcement programs, notification letters outline the specific reasons for PHMSA’s determination and identify PHMSA’s right to enforce federal standards within the state. Federal civil penalties range from $205,000 per day for a violation, up to a maximum of more than $2 million for a series of related violations.

In addition, these states are notified that they may risk losing federal grant funding in support of state pipeline safety initiatives if they fail to establish adequate enforcement programs within five years.

As of February 2017, PHMSA sent notifications to 30 states, of which 10—Alabama, Alaska, California, Colorado, Delaware, Idaho, Mississippi, Montana, West Virginia and Wisconsin—were determined to have inadequate enforcement programs.  

 State One-Call Laws

While state one-call laws vary, they share several common elements. For example, there are basic elements that form the foundation of the damage prevention law:

Excavator Notice

All states require the excavator to give notice of the project to all operators of underground infrastructure prior to excavation. In some cases, that means the excavator must call a one-call center (by dialing “811”), which will then notify all operators of underground infrastructure that are members of the one-call center. In other cases, the excavator must contact operators directly. And, in a few cases, the excavator must do both. 

The excavator must notify the facility operators within a specific timeframe in advance of beginning excavation. In addition, all states have established in statute a notification timeframe that excavators must abide by, with 37 states and the District of Columbia requiring notification at least two working days prior to the planned excavation. Twelve states require notice at least three days in advance, while Hawaii is the only state that requires excavators to give notice five days prior to work commencing.

Operator Response

Operators notified of a planned excavation must locate and mark their underground facilities. Consistent with the minimum time required for excavators to provide notification, most states require that operators mark their facilities within two working days after receiving notice. Eleven states give operators three days to mark facilities, while Hawaii grants operators five days. 

Several states allow the operator to coordinate the time with the excavator, or to respond to an excavation notification prior to the excavation start date if it is later than two days. For example, Minnesota statute technically requires that operators respond within four days of an excavation notice. However, since it also sets the minimum notification time from excavators at two days, this creates a de facto two-day marking timeline for operators under certain circumstances. So, while an operator may be able to wait four days if the excavation notice is given six days in advance of the start of excavation, they could also have to respond within two days if the excavator waits to notify until the last minute.

A number of state statutes work in a similar fashion, where the requirements on one party impose reciprocal requirements on another.

Positive Response

“Positive response” is another significant, though not universal, element in one-call laws. In practice, positive response is a communication made to the excavator prior to excavation, to assure that underground facilities in the planned excavation area have been located and marked, identifying any potential conflicts where damage could occur.

In 33 states, the law allows the markings made by operators to constitute positive response. In some cases, this is the only form of positive response outlined. In others, the statute details specific steps that constitute positive response. For example, in Ohio, the operator must contact the excavator directly to communicate the presence or absence of underground infrastructure on the project site.

This is viewed as a very important aspect of positive response. While markings clearly indicate that the operator has fulfilled its obligation, the absence of markings doesn’t clearly indicate anything. It could mean that the operator has looked over the site and determined they have no facilities, or it could mean that they forgot or haven’t gotten to it yet.

This potential for miscommunication can be dangerous, which is why 31 states and the District of Columbia require operators to communicate to the excavator, in one form or another, that their work has been completed.

Ohio requires not only that operators contact excavators directly, but also the one-call center, providing each with any additional information or guidance that could help avoid damage. Many states require operators contact either the excavator or the one-call center, and a number of states funnel these communications through one-call centers so that all communications are tracked through a central system.

Additionally, some states require the excavator to contact the one-call center to verify that all operators have marked their facilities—a task sometimes accomplished via automated voice systems. The positive response requirement is a means of closing the communication loop—a way to ensure that both parties are on the same page by requiring that operators get back in touch with excavators to let them know that the request has been closed.

Damage Notification

The only other element that is nearly universal is a “damage notification” requirement. In fact, every state except Montana requires that excavators who damage underground infrastructure notify either operators or the one-call center as soon as possible.

State one-call laws can generally be analyzed based on the following components: communication, standards and enforcement. Most states specify standards within their one-call law. However, in some cases where the law doesn't’t specify standard practice, industry has established its own standards which are widely followed and even considered enforceable.


Effective communication between excavators and operators is of primary importance. While this is the basis of every state law, the specifics of how these two parties should communicate is not always standardized in statute.

PHMSA states that these should be addressed explicitly to avoid crossed signals and to assist in any necessary investigation. PHMSA recommends a ticketed system that is run through a one-call center, where every new excavation project receives a traceable ticket. The one-call center would be responsible for tracking which operators have responded, along with notifying the excavator when all outstanding location requests have been satisfied.

A major element of this is positive response. Without some form of positive response, the communication loop may never be closed and an excavator is left to begin work under the assumption that all underground infrastructure has been marked. In some cases, however, that assumption could be wrong.

To avoid this, PHMSA recommends a system that allows an excavator to know for sure which locate tickets have been closed out, and which remain open.

In addition, the communication component includes whether damage notification is required. It is important for operators to receive prompt notification of damage to facilities for several reasons—the most critical being potential harm to life and property. This is especially true when the damage is to pipelines that carry hazardous materials like natural gas and oil. When this type of damage occurs, federal law requires an excavator to call 911 as soon as possible.

Currently, 15 states do not require excavators to call emergency services upon the release of hazardous materials due to excavation work.


To one degree or another, most state laws create certain standards for excavators and operators. This can be as simple as establishing a tolerance zone, or as complex as outlining under what circumstances an excavator must resort to hand-digging in order to avoid damage. The Common Ground Alliance, a national nonprofit focused on damage prevention, publishes a set of best practices that are widely referenced in the industry.

Every state’s damage prevention law establishes a “tolerance zone” for excavating near pipelines. A tolerance zone is an area in which excavators must exercise heightened caution. It generally consists of the width of an underground facility, as marked by an operator, plus an added buffer of 18 to 24 inches on either side. Two states have implemented larger tolerance zones. Hawaii has established a tolerance zone of 30 inches, while Michigan’s tolerance zone is 48 inches.

The tolerance zone is determined from outside dimensions of the underground facility, which is identified through painted or flagged markers on the surface of the excavation site.

States differ in the way they treat tolerance zones. Inside of these tolerance zones, many states require excavators to adopt excavation practices that are less likely to result in damage. Some require test holes to determine the precise location of underground facilities, prohibit mechanized equipment from being used, or prescribe a specific excavation method that ought to be employed. In all, 39 states have established special digging requirements within the tolerance zone.

All states address marking standards in their statutes or administrative codes. These outline the marking colors to be used, along with additional marking standards for operators. Of those, 34 states have adopted the American Public Works Association Uniform Color Code. The other 16 states specify a color code without reference to any recognized standard, or reference another standard such as the Uniform Color Code adopted by the American National Standards Institute. 

While the PIPES Act identified the use of performance measures for locators of underground facilities as a key consideration for damage prevention programs, only five states—California, Kansas, New Hampshire, North Carolina and Virginia—address training standards for locators in statute.


PHMSA's evaluation of state enforcement has centered around whether state laws are sufficient and whether states are enforcing the laws. One area of interest has been the fines states can levy against violators. The evaluation criteria requires that states have the ability to issue fines against excavators and operators who fail to comply with the law.

Photo of gold justice scale photo.PHMSA is also interested in the level at which the fines are set for excavators and whether they are sufficient to discourage violation of the law. Many states assess fines on an escalating scale for successive violations. Some states assess higher civil penalties if personal injury, death, or property damage occurs because of a violation. Kentucky and Louisiana have established fines of $250 for the first offense, while additional offenses can cause fines to increase. Alternatively, Alaska has set maximum fines of $1,000 for each violation. Several states have established maximum fines that are not to exceed $10,000, while others have set maximums between $10,000 and $25,000.

Another critical area is whether the state has designated an enforcement authority to administer the law. Without clear designation in statute, state agencies may not view enforcement as part of their mandate. Only four states—Alaska, Kentucky, Montana and West Virginia—do not address who is to enforce the state damage prevention law. The majority of state laws designate one or more agencies responsible for enforcement. Twenty-three states grant enforcement powers to state public utilities commissions—or state departments that oversee utilities in some way. Seventeen states designate the attorney general, a district attorney, other prosecuting attorneys, facility operators, or other aggrieved parties, while three states assign enforcement to codes inspectors and local law enforcement.

Four states have established bodies specifically to be responsible for enforcement of one-call laws: the Maryland Underground Facilities Damage Prevention Authority; the Mississippi Underground Facilities Damage Prevention Board; the South Dakota Statewide One-Call Notification Board; and the Tennessee Underground Utility Damage Prevention Enforcement Board, which is under the Tennessee Regulatory Authority. Other states, such as Georgia, Indiana and Virginia, have established similar boards that serve in an advisory capacity to a state authority with the power to issue fines. One argument in favor of this type of enforcement authority is that they have a limited scope of responsibilities, which means that their sole focus is on enforcing a law which other agencies may not consider a top enforcement priority.

Nine Elements of Damage Prevention

Every state has unique qualities that inform excavation damage prevention laws. More rural states with less underground infrastructure may not feel the need to employ stringent parameters on excavators, while densely populated states may decide that safeguards need to be clearly outlined in statute.

While these regional and local differences are understandable, Congress established nine elements in the PIPES Act that outline the processes and characteristics that should be reflected in comprehensive and effective damage prevention programs. In many cases, these are not prescriptive and can be interpreted to reflect the realities within each state.

The nine elements for comprehensive and effective damage prevention programs:

  1. Enhanced communication between operators and excavators.
  2. Fostering support and partnership of all stakeholders.
  3. Operator’s use of performance measures for locators.
  4. Partnership in employee training.
  5. Partnership in public education.
  6. Enforcement agencies’ role to help resolve issues.
  7. Fair and consistent enforcement of the law.
  8. Use of technology to improve the locating process.
  9. Data analysis to continually improve program effectiveness.


The nine elements call for increased communication and participation from all stakeholders, including the public. There are specific areas of focus, such as training and measuring the performance of employees who mark underground facilities and clear channels of communication between operators and excavators to avoid mixed-signals. However, there are also other areas that may not be addressed in state law, including support and participation from all stakeholders, fairly and consistently enforcing the law and incorporating data to improve a program’s effectiveness.

The goal is to create a program structure that is consistent, clear and effective—a program that offers clear expectations to industry and protects the integrity of underground infrastructure and the safety of people and property.