By: Russell H. Brooks, P.G. | Senior Engineer
The federally-mandated, national “Call Before You Dig” number, 811, was created to help prevent unintentionally hitting underground utility lines while working on excavation, drilling, or similar subsurface projects. People often make risky assumptions regarding marking utility lines due to concerns about project delays, costs, and experience (or luck) with other projects in which utilities were not marked. These assumptions can be life-threatening.
Every excavation/drilling job requires a call – even small projects like planting trees or shrubs. Hitting an underground utility line while digging can seriously harm you or those around you, disrupt service to an entire neighborhood or industrial park, and potentially result in significant fines and repair costs.
The 811 system will notify member utilities; however, in many cases small local municipalities are not members of the 811 system. Therefore, it is your responsibility to identify and contact non-member utility providers.
Typical environmental jobs often include subsurface activities, such as drilling soil boring and groundwater monitoring wells, and excavating to remove impacted soils, waste materials and underground storage tanks (USTs). The 811 call should be made 48 to 72 hours prior to commencing work on all subsurface operations. Depending on individual state laws, you must account for holidays and weekends, so do not call on Friday and expect the utilities to be located on Monday.
An 811 utility locate request will only mark utilities up to the service meter for the property. It is the responsibility of the contractor to ensure that all utilities beyond the meter are properly located and marked prior to the start of work.
In cases of large coverage areas, the utility clearance company has the right to request work area demarcation prior to marking the utilities. Identifying work areas on large sites helps to minimize the locator’s time on-site, and also confirms that utilities in work areas have been marked.
Site utilities will be marked with paint and flags. The following universal color system indicates what is buried below the surface:
Red – Electric
Orange – Communications, Telephone/CATV
Blue – Potable WaterGreen – Sewer/Drainage
Yellow – Gas/Petroleum Pipe Line
Purple – Reclaimed Water
White – Area of Intended Excavation/Subsurface work (marked by contractor)
Once the utilities are marked it is the excavator’s/driller’s responsibility to avoid damaging the utilities. Although no specific “hand-dig” zone is outlined in the Call Before You Dig law; the American Public Workers Association and several industry-accepted Best Practices recommend hand-digging 18″ on either side of the utility markings to a depth of 24″. It is recommended that shovel excavation or a similarly gentle method of excavation take place in the hand-digging zone to uncover utilities prior to proceeding with more powerful equipment.
For more information about the national 811 system, visit http://www.call811.com