Frequently Asked Questions (FAQ)

Question:
What is the recommended horizontal and vertical separation for underground utilities?

Answer:
Pipelines and utilities shall not be installed closer than two feet from any other pipeline or utility; three feet from any sewer line. Waterlines shall not be installed closer than ten feet from a sewer line unless evidence of permission from the Division of Drinking Water (DDW) is provided.

The following minimum depths of cover, below gutter flow line grade, shall be required (§16.18.040):

LOCAL STREETS
24" for service pipelines
30" for all pipelines transporting nonhazardous substances
30" for electrical facilities
42" for pipelines transporting hazardous substances

MASTER PLAN HIGHWAYS
24" for service pipelines
36" for pipelines transporting nonhazardous substances
42" for electrical facilities
42" for pipelines transporting hazardous substances

If the lines are stacked on top of one another as part of a joint trench (typical for subdivision/tract developments that functions as one trench to hold all the utility lines), the normal vertical separation is 1 foot.