6.2 Utility Color Codes, the 18-Inch Safety Zone, Excavating Near Facilities & Damage Response

Standard color code

MGL c. 82 § 40 says companies mark facilities by methods that follow the Common Ground Alliance and American Public Works Association (APWA) standards. The statute and 220 CMR 99.02 assign these colors:

How utilities mark (220 CMR 99.06)

• Timing: within 72 hours, excluding Saturdays, Sundays and legal holidays, of the notice reaching the Dig Safe Center (§ 40B allows an agreed time instead). For long excavations, the company marks the first portion within 72 hours and the rest within a reasonable time.
• Method: visible marking material such as paint on the ground above the facility, or color-coded stakes, flags or brush-type markers. Companies use the center-line method on public and private property.
• Where practicable, marks show the facility's width (if over 2 inches), material, changes in direction and terminus points.
• Marks extend at least 15 feet beyond the premarked area (§ 40B: within 15 feet in any direction of the premarking).
• Offset marks may be used where the surface above will be removed, uniformly aligned and showing the distance to the facility.
• Historical paved areas may be marked with chalk, stakes, flags or brush markers instead of paint.
• New facilities are marked as they are backfilled or installed.
• No facilities? The company tells the excavator or otherwise shows that no facilities are present.

The safety zone

The statute defines the safety zone as a zone marked on the surface with the standard colors that contains the width of the facilities plus not more than 18 inches on each side. 220 CMR 99.06(2) adds that the facility must lie completely within the safety zone, no more than the width of the facility plus 18 inches on each side of the designated center line.

Worked example. A 12-inch gas main is marked on its center line. The facility can be anywhere within $12 + 18 + 18 = 48$ inches, so a 4-foot-wide band, centered on the mark. Bucket teeth do not go into that band to "find" the pipe.

Excavating near marked facilities (MGL c. 82 § 40C; 220 CMR 99.07)

1. Wait 72 hours. No excavation within 72 hours of notification (99.07(1)).
2. Non-mechanical means near facilities. When excavating close to underground facilities, use non-mechanical means as necessary to avoid damage while locating them. These are tools powered by people, including air vacuum and air blowing methods designed to minimize contact. Mechanical means may only be used for the initial penetration of pavement, rock or similar material, after which non-mechanical methods take over (99.07(3)).
3. Protect the facility after it is exposed. Further excavation uses reasonable precautions against damage, including weakening of structural or lateral support, penetration or destruction of the pipe, main, wire or conduit or its protective coating.
4. Keep the marks alive. The excavator is responsible for maintaining the marks or placing offset marks in the standard colors, or for asking Dig Safe for re-marking (99.07(4)).
5. Re-marks. The company re-marks within 24 hours of the request, excluding Saturdays, Sundays and legal holidays (99.06(6); § 40C). The excavator suspends excavation in that area for 24 hours after requesting a re-mark (99.07(5)).
6. Unmarked facility found. If there is clear evidence of an unmarked facility, suspend excavating until Dig Safe is notified, and protect the facility (99.07(6)).
7. Abandoned facilities are removed only with the owning company's authorization and direction (99.07(7)).

If a facility is damaged (220 CMR 99.07(8)–(10); § 40C)

Crane setups near marked facilities

A crane outrigger is not an excavation tool, but it puts a heavy, concentrated load on the ground. When marks show a shallow gas service, conduit bank or sewer under the planned outrigger position, treat it as a ground-condition hazard. OSHA 1926.1402(c)(2) requires the controlling entity to tell the operator about utilities, voids and tanks beneath the setup area that are shown in its documents or otherwise known. Move the setup, or have a qualified person design mats or bridging so the load stays off the facility (Section 7.2).

Scenario practice

The "gentle tooth." An operator scrapes inside a yellow safety zone with the corner of a backhoe bucket to locate a 2-inch plastic gas service. The tooth snags the service and gas escapes. This is mechanical excavation inside the zone where non-mechanical means were required (99.07(3)). Required response: 911 immediately, evacuate as needed, notify the gas company, no repairs, and report to the DPU within 30 days. As a 230 CMR 6.08(2)(c)18 issue, the operator's license is also at risk.

Rain washes out the paint. After a heavy storm, the red marks on a trench line are gone. The excavator requests a re-mark and suspends excavation in that area for 24 hours while the company re-marks.