DTE ENERGY’s BEST PRACTICES FOR

GEOSPATIAL DATA COLLECTIONAdolfo Castillo, P.S.

Professional Surveyor

January 12, 2015

A look at DTE Energy’s Geospatial Data

Collection safety practices on new

underground utility installations within

MDOT’s R.O.W.s’

3

4.1

Ft

> 2 Ft

Open cut excavation – Anatomy of a Gas explosion

Existing Gas Main

New Gas Main

Gas mainSlow leak

?

?

Commercial

Buildings

MDOT’s R.O.W.

MD

OT

’s R

.O.W

.

Shopping PlazaShopping Plaza

A

A

LEGENDNew Utility Installation

Exposed steel gas main

Buried steel gas main

Open Cut Excavation

Strong GPS Reception/Signal

Unconfined gas following the path of least resistance

Open cut excavation – Gas explosion

Deflection Points

Deflection Points

100 Ft. interval Typ.

Terminus Point

Cross Section View

4

Leaking gas main

GPS Rover

5

Temperature within a single spark equals 5,000 ° F to 8,000 ° F common voltage,

amperage and medium (gas/air) vary to 1,000,000 ° F

Facts

The actual temperature of a lit cigarette = 752° F or 400z

Highest temperature of a lit cigarette (At draw) = 1292 ° F or 700 ° C.

The Auto ignition Temperature of a standard unleaded gasoline varies from 475 ° F to 536 ° F or 246 ° C to 480 ° C

The Auto ignition Temperature of Methane (Natural Gas) = 1076 ° F or 580 ° C

Source of information: The Engineering Tool Box, and Physics and Astronomy Online.

6

9 F

t

Existing installation

New installation

Open cut excavation – Anatomy of a trench cave-in

1’

?

?

Commercial

Buildings

MDOT’s R.O.W.

MD

OT

’s R

.O.W

.

Shopping PlazaShopping Plaza

B

Open cut excavation – Earth wall collapse

Deflection Points

Deflection Points

Terminus Point

Cross Section View

7

B

< 1

’

> 2

’ > 2

’

Utility Installation

Open Cut Excavation

Strong GPS

Reception/Signal

Excavation Spoil

GPS Rover

LEGEND

8

MORE FACTS

From 2004 through 2013, the U.S. had:

• 286 trench cave-in incidents. 163 fatalities. 10 of the 286 cave-in incidents occurred in Michigan, 9 of them fatal.

• 745 serious incidents with gas distribution, causing 278 fatalities and 1059 injuries, with $110,658,083 in property damage.

• 110 serious incidents with gas transmission, resulting in 41 fatalities, 195 injuries, and $448,900,333 in property damage.

Data source: United States Department of Labor. OSHA Fatality and Catastrophe Investigation Summaries

Open cut excavation with Trench Box

6 Ft

9F

t

Existing installation

New installation

Trench Box

Open cut excavation with Hydraulic Bracing

6 Ft

9F

t

Existing installation

New installation

Hydraulic Braces

Steel Sheeting

Steel Sheeting

11

13.5’

9 F

t

Existing installation

New installation

4Ft

1’

1.5’

Open cut excavation with Sloped Side-Walls

• Trenches 20 feet (6.1 meters) deep or greater require that the protective system be designed by

a registered professional engineer or be based on tabulated data prepared and/or approved by a

registered professional engineer in accordance with 1926.652(b) and (c).

• OSHA standards require safe access and egress to all excavations, including ladders, steps,

ramps, or other safe means of exit for employees working in trench excavations 4 feet (1.22

meters) or deeper. These devices must be located within 25 feet (7.6 meters) of all workers.

.

.

.

• Keep heavy equipment away from trench edges.

• Trenches 5 feet (1.5 meters) deep or greater require a protective system unless the excavation is

made entirely in stable rock. If less than 5 feet deep, a competent person may determine that a

protective system is not required.

Rules for working in and near excavations

Data source: United States Department of Labor. OSHA Trenching and Excavation Safety

.

.

.

• Identify other sources that might affect trench stability.

• Keep excavated soil (spoils) and other materials at least 2 feet (0.6 meters) from trench edges.

• Know where underground utilities are located before digging.

• Test for atmospheric hazards such as low oxygen, hazardous fumes and toxic gases when > 4 feet

deep.

• Inspect trenches at the start of each shift

Rules for working in and near excavations

Data source: United States Department of Labor. OSHA Trenching and Excavation Safety

.

.

.

• Inspect trenches following a rainstorm or other water intrusion

• Do not work under suspended or raised loads and materials.

• Inspect trenches after any occurrence that could have changed conditions in the trench.

• Ensure that personnel wear high visibility or other suitable clothing when exposed to

vehicular traffic.

Rules for working in and near excavations

Data source: United States Department of Labor. OSHA Trenching and Excavation Safety

Questions ?

Comments?

Gracias

Thank you for your attention to this presentation, and for your participation.