Before digging, you must call 811 or (800) 922-1987 whether you are doing it yourself or hiring a contractor.

Utility location is the process of identifying and labeling public utility mains which are underground. These mains may include lines for telephones, electricity distribution, natural gas, cable television, fiber optics, traffic lights, street lights, storm drains, water mains, and wastewater pipes. In some locations, major oil and gas pipelines, national defense communication lines, mass transit, rail and road tunnels also compete for space underground. 

ELCO requires two business days notice before you dig. STATE LAWS CRS 1973, 9-1.5-101 (SENATE BILL NO. 172-1981) REQUIRES EVERYONE PLANNING TO DIG IN OR NEAR A PUBLIC ROAD, STREET, ALLEY, RIGHT OF WAY OR UTILITY EASEMENT TO NOTIFY THE UTILITY OWNERS OF YOUR INTENT TWO BUSINESS DAYS BEFORE YOU DIG

ELCO states that 18 inches from locate markings is considered an accurate and correct locate.

No, the District will locate water mains and service lines up to the water meter. The District does not locate customer-owned service lines on private property as a general rule. Some plumbers have equipment that can locate private water service lines.

ELCO does not guarantee depths on any utility lines. At the time of installation all lines are inspected and comply with codes. However, grade may be changed as a result of construction.