Locate Marks |
Locate marks, be they paint, stakes or flags, should be in sufficient quantity and close enough together to clearly identify the horizontal alignment of the buried facilities.
While locating equipment is becoming increasingly more sophisticated and accurate, parallel facilities, overhead facilities and nearby reinforced concrete structures all affect their accuracy. Locating is thus part art and part science and locate marks are approximate only.
Locators should identify and mark the locations of abandoned facilities whenever possible. They should also identify the number of facilities the ground disturber can expect to find whenever that information can be determined.
Locators will not give depth but should warn the ground disturber if they suspect a particular facility is deeper or shallower than might normally be expected.
The marking of the locations of buried facilities in Alberta follows the Uniform Color Code introduced by the American Public Works Association and partially recognized in Canadian Standards Association C22.3 No. 7-94, Underground Systems.
WHITE |
Limits of proposed excavation |
PINK |
Temporary survey marks |
RED |
Electric power lines, cables, conduits and ducts or lighting wires and cables |
YELLOW |
Gas, oil, petroleum, steam or gaseous materials |
ORANGE |
Telephone, cable TV, communications, alarm or signal lines, wires, cables, conduits or ducts |
BLUE |
Potable water lines or pipes |
GREEN |
Sanitary sewer, storm sewer, culvert or drain lines |
PURPLE |
Irrigation, reclaimed water or slurry lines or pipes |
Where facilities are marked with a single line of paint, flags or stakes, the marks indicate the approximate centreline of the facility. Where facilities are marked with parallel lines connected with an arrow or chevron, the marks indicate either the approximate trench width of the original installation or the approximate outside limits of the facility.
LOCATE DOCUMENTATION
The documentation of locates performed is proof that the locator understands the scope or extent of the ground disturbance, that the locates have been done and that the ground disturber understands what has been located, and must be kept on site. It should be in the possession of and understood by the person actually disturbing the ground.
Documentation should provide sufficient information to allow the re-establishment of the locate marks should that ever be necessary and should include any special requirements the facility operator might have with respect to that particular ground disturbance.
Locators and ground disturbers may choose to take and retain photographs of locates for their further protection.
LIFESPAN OF LOCATES
Locates are valid for as long as the locate marks are visible but generally for not more than 14 calendar days from the date they were provided. Locates may be valid for 30 calendar days from the date they were provided subject to certain conditions’ being met.
If a ground disturber doe not commence a proposed ground disturbance within 14 calendar days of the date locates were provided, the ground disturber must request new locates.
If a ground disturber has commenced a proposed ground disturbance within 14 calendar days of the date locates were provided but has not completed the ground disturbance, the locates are valid for 30 calendar days from the date they were provided, subject to the following conditions:
a. the locate marks remain visible or the ground disturber has provided more permanent references or the ground disturber has exposed the buried facilities in conflict with the proposed ground disturbance and documented their actual location;
b. the ground disturber’s activity at the site has not been interrupted, except for
i. maximum 4 calendar day periods over weekends, or
ii. any period of time where weather situations dictate longer interruptions or interruptions during the week provided that during such interruptions the site must be monitored by a competent person and such monitoring must be documented; and
c. the ground disturber’s presence at the site remains evident during such interruptions (e.g. fencing, barricades, signage, equipment on site, job shack, evidence of work in progress).
If a ground disturber has not completed a ground disturbance within the extended period of 30 calendar days from the date locates were provided, the ground disturber must request new locates.
On receipt of a request for new locates, individual operators of buried facilities, in consultation with the ground disturber, will determine whether a new locate is required or the lifespan of the existing locate can be extended.
For large or long term projects, it is expected that the ground disturber will break the project into sections when placing locate requests to better coordinate the provision of locates with the progress of the ground disturbance.
If at any time the ground disturber is of the opinion that the locate marks are not adequate for the successful and safe completion of the work, the ground disturber must request new locates.
The following flow chart of work site scenarios explains the
lifespan of locates.
