CO811 Educational Resources

Learn more about Colorado 811


Procedure GuideProcedure Guide

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Table of Contents:

  • Hours of Operation Page 2
  • Glossary Page 3
  • Required Information for requesting a Locate Page 6-9
  • Normal Request Page 10-15
  • Non-Compliance Request Page 16-17
  • Cancel Request Page 18
  • County Road Grading Page 19
  • Excavator Re-Notification Page 20-21
  • Relocate/Refresh Request Page 22
  • Emergency Request Page 23-24
  • Damage Request Page 25-26
  • Engineering Request Page 27
  • Subsurface Utility Engineering Page 28-29



Excavator Handbook cover

Excavator handbook

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Table Of Contents

  • Determining Whom And When To Call Prior To Excavation
  • Types Of Locate Requests Processed By Colorado 811
  • Guidelines For Preparing To Call Prior To Excavation
  • What Happens After The Call Is Made
  • Responsibilities Of The Facility Owner(S)/operator(S) (After Receiving The Locate Request)
  • Responsibilities Of The Excavator (After Making The Call For A Locate Request)
  • Reporting Problems
  • One-call Legislation
  • Other Applicable Laws And Regulation
  • Recognizing And Responding To Emergencies InvolvingDamaged Facilities

Color Code Card


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Frequently Asked Questions

Yes, no matter how shallow or how deep you are digging, you must contact 811 first. Colorado State law defines excavation as “any operation in which earth is moved or removed by means of any tools, equipment, or explosives and includes augering, backfilling, boring, ditching, drilling, grading, plowing-in, pulling-in, ripping, scraping, trenching, hydro excavating, postholing, and tunneling”.

You need to contact 811 before you dig, so you can avoid hitting any underground utilities, such as cables, wires or pipes. It’s also the law to contact 811 before you dig.

There is no cost, it’s a free service.

Yes, you can quickly submit a locate request online through Ticket Express. Learn more about Ticket Express here.

The utility companies will mark the lines, some have in-house locators who mark their lines, while other hire a locating firm to mark their lines. Colorado 811 is not a locating company and does not locate utilities.

You can start digging once you have all your markings or positive response from the utilities on your ticket.

Positive Response is mandated under the Colorado State law, to be provided by the underground facility owner to the excavator or homeowner requesting the locate request. The facility owner is required to post Positive Response through the Colorado Positive Response system. Positive Response lets the excavator or homeowner know the status of the ticket.

Utility owners and operators follow the APWA (American Public Works Association) standard color code to mark the locations of their underground facilities. The following colors are used:

RED – Electric Power Lines, Cables, Conduit and Lighting Cables
YELLOW – Gas, Oil, Steam, Petroleum or Gaseous Materials
ORANGE – Communication, Alarm or Signal Lines, Cables or Conduit
BLUE – Potable Water
PURPLE – Reclaimed Water, Irrigation and Slurry Lines
GREEN – Sewers and Drain Lines
WHITE – Proposed Excavation
PINK – Temporary Survey Markings

A facility owner is an organization such as companies, municipalities, etc. who own and/or operate underground utilities. Facility owners that register their underground utilities with Colorado 811 are known as members.

The depth of utilities varies by location and by type. Erosion or leveling may cause the depth of a utility to change over time. For that reason, utility owners/operators only indicate depth if it is known.

Private utilities are owned by the owner of a property and will not be marked with your request. These can include water and sewer laterals, power to a detached garage, sprinkler/irrigation systems, lines connected to a propane tank or septic system, etc. There may be private utilities within your dig area. It is your responsibility to have private facilities marked. For a list of private locating companies, please visit