In directional drilling, each bore presents a new and unique challenge. Soil conditions can change from one extreme to the other within the same bore. Often, the bore path is congested with existing underground utilities that must be avoided. Overhead power lines, microwave towers, traffic light loops, and steel reinforcing in concrete are just a few examples of items that can interfere with locating the drill head. With all the potential pitfalls, the ability to successfully complete a bore often hinges on advance planning.

In this chapter, we will discuss planning the bore as it pertains to the drilling contractor. There are special planning considerations for environmental remediation work which would normally be performed by an environmental engineer.

Existing Utilities

One of the first considerations in planning the bore should be the location of underground utilities. In the United States there are a number of companies that provide this service to the contractor. They are generally referred to as "One Call" notification services. One Call notification services vary somewhat from state to state since there is currently no uniform federal law. However, they all require notification, generally 48 -72 hours depending on the state, before any boring, trenching, or excavating can begin. They will locate all known utilities along the proposed bore path. However, they typically do not provide depth information. It is the contractors responsibility to expose (pot hole) every utility that intersects the bore path to determine the exact location. Remember, pot holing is the only reliable method for determining where the existing utility is located.

At the end of this chapter you'll find a directory of One Call services. The caller will be asked to provide the following information:

• Name of county and township or municipality
• Section number
• Street address
• Type of work
• Name of caller
• Title of caller
• Start date and time
• Best time to call back
• Contractor
• Contractor's address and phone number

Once this information is provided, the caller will be given a job number. This number is proof that One Call was notified and it should be retained for future reference in the event that a problem arises.

The uniform color code for marking underground utility lines is as follows:

RED

Electric

YELLOW

Gas -- Oil -- CATV

ORANGE

Communication -- CATV

BLUE

Water

GREEN

Sewer

PINK

Temporary survey markings

WHITE

Proposal excavation

Most of the world does not have the benefit of a One Call service, and the contractor is directly responsible for all locates. Quite often, maps containing information on the location of underground utilities are not available. In these cases, it is even more important that time is spent reading the job site to determine the location of all utilities. Items to look for that might indicate a buried utility could include:

• A ditch line depression in the landscape.
• A building with lights that has no wires coming in overhead.
• A patch in the blacktop or concrete street. Any pole with electric wires extending down into the ground.
• Transformer boxes.
• Manhole covers.
• Water or gas shut-off valves.

While checking the site for utilities, you must ask yourself, "How was this utility installed?" If it was plowed or trenched, there is a good chance that the depth will be fairly consistent. On the other hand, if it was installed with a backhoe, the depth could vary considerably.

Machine Placement

There are several items that need to be considered when determining machine placement. The major factor will be the physical limitations of the site itself. There has to be enough room to set the machine up so that maximum depth can be obtained without exceeding the bend radius of the drill pipe. (See Drill Pipe Specifications chart at end of chapter.) There also has to be enough room to accommodate the product being installed. If there are any variations in the elevation from one end of the bore path to the other, it is better to drill downhill. This will help to keep the drilling fluid in the hole instead of having it run out by the machine.

To determine the minimum set-back distance required to obtain a specter depth, the desired depth and the rack angle of the machine must be known. Dividing the rise (depth) by the rack angle will calculate the minimum set-back distance required to obtain the desired depth. This assumes a straight line with no steering corrections. If the drill head needs to be level at the desired depth, then it will be necessary to add approximately 30 feet to the set-back distance. The footage required to level the drill head will vary depending on the bend radius of the drill pipe that is being used.

Two other formulas that can be useful when determining the proper rack placement are:

RISE / RUN = ANGLE and RUN X ANGLE = RISE

Bore Path Interference

Overhead power lines, traffic light loops, and steel reinforcing in concrete are just a few examples of items that can interfere with locating the drill head. Metal buildings, invisible dog fence, and automobiles with electronic fuel injection can also cause interference. Interference with the locating equipment can cause serious problems and can prevent a bore from being completed. By checking for interference along the bore path before any drilling begins, it might be possible to eliminate the problem. If the problem can not be eliminated, it will be easier to deal with by just knowing that there will be a problem in a certain area.

To check for interference, walk the bore path with the receiver before powering up the sonde. Watch the signal strength on the receiver. Any high signals along the bore path could indicate a problem area. It is advised to mark these areas so the crew member doing the locating will be prepared for the problem.

Determining Grade

When planning the bore, it is a good idea to determine the grade of the topography of the proposed bore path. This can be quite helpful when trying to maintain a constant depth. This is easily accomplished by laying the sonde on the ground, taking a pitch reading with the receiver, and recording the information. Repeat this process any place where the slope of the ground changes. Once the maximum depth is obtained, it can be maintained by keeping the pitch of the drill head consistent with the slope of the surface.

Mud Requirements

A well-planned bore includes knowing how much drilling fluid will be required. This will vary from job to job depending on soil conditions and the size of the back reamer being used. A good rule of thumb for estimating the amount needed is to take the diameter of the back reamer squared and divide that number by 24.5. The answer will be the number of gallons per foot of bore. We will cover this in more detail in Chapter 3, Drilling Fluids and Back Reaming.

Summary

The bore planner on the following page can prove useful not only for planning, but also for recording the bore as built. The most important part of the planning process is to supply a list of emergency phone numbers to the crew. HDD is safe, but just like any other occupation, accidents can occur. Having these phone numbers available could save a life. Some other items that need to be considered in the planning stage are:

• What type of product is to be installed? Is it on hand?
• What size and type of back reamer is needed? Will prereaming be necessary
• Are batteries for the locator fully charged? Are new batteries on hand for the sonde? What about the batteries for the walkie-talkies?
• Is there plenty of thread compound? How about a paintbrush for applying the thread compound?
• Everyone on the crew should have their own tasks that they are responsible for. This will speed up the drilling process considerably.
• Make sure that the proper safety equipment is on hand and ready for use.

By planning the bore and having everything ready, the chance of performing a successful bore increases dramatically. It is also more professional.

Bore Planner

Customer

Date

Address

Job #

City, State, ZIP

Contact Person

Phone

Phone

Location of bore_________________________________________________________________

Type and size of product to be installed_______________________________________________

Estimated Length of bore__________________________________________________________

________Water

_______Paint Brush

________Bentonite

_______Location Flags

________Polymer

_______Duck Bills

________Batteries for Locator

_______Back Reamers

________Thread Compound

__ Gravel

__ Loam

__ Hardpan

__ Sand

                       __ Clay

                   __ Other

Size  ________

Type  ________

Preream        Yes/No

Ambulance

_______________________________________

Electric company

_______________________________________

Gas company

_______________________________________

Phone company

_______________________________________

Water company

_______________________________________

Sanitation Department

_______________________________________

One Call locating service contacted on_____/______/______By________________________

Name of person contracted:_____________________________________________________

One-Call Directory

ALABAMA Alabama Line Location Center 1-800-292-8525

ALASKA Locate Call Center of Alaska, Inc. 1-907-278-3121

ARIZONA Arizona Blue Stake, Inc. 1-800-782-5348

ARKANSAS Arkansas One Call System, Inc. 1-800-782-5348

CALIFORNIA

Underground Service Alert North 1-800-227-2600

Underground Service Alert South 1-800-227-2600

COLORADO

Utility Notification Center of Colorado 1-800-922-1987

CONNECTICUT

Call Before You Dig 1-800-922-4455

DELAWARE

Miss Utility of Delmarva 1-800-282-8555

FLORIDA

Sunshine State One Call of Florida, Inc. 1-800-432-4770

GEORGIA

Utilities Protection Center, Inc. 1-800-282-7411

IDAHO

Dig Line 1-800-342-1585

Palouse Empire Underground Coordinating Council 1-800-822-1974

Kootenai County Utility Coordinating Council 1-800-428-4950

Utilities Underground Location Center 1-800-424-5555

One Call Concepts -Idaho 1-800-626-4950

Shoshone County One Call 1-800-398-3285

ILLINOIS

Julie, Inc. 1-800-892-0123

Chicago: Digger 1-312-744-7000

INDIANA

IN Underground Plant Protection Services, Inc. 1-800-382-5544

IOWA

Underground Plant Location Service, Inc. 1-800-292-8989

KANSAS

Kansas One Call Center 1-800-DIG-SAFE

KENTUCKY

Kentucky Underground Protection, Inc. 1-800-752-6007

LOUISIANA

Dottie System, Inc. 1-800-272-3020

MAINE

Dig Safe ---- Maine 1-888-344-7233

MARYLAND

Miss Utility of Delmarva 1-800-282-8555

Miss Utility 1-800-257-7777 MASSACHUSETTS

MASSACHESETTS

Dig Safe Massachusetts 1-888-344-7233

MICHIGAN

Miss Dig Utility Communication System 1-800-482-7171

MINNESOTA

Gopher State One Call 1-800-252-1166

MISSISSIPPI

Mississippi One Call System, Inc. 1-800-227-6477

MISSOURI

Missouri One Call System, Inc. 1-800-344-7483

MONTANA

Utilities Underground Location Center 1-800-424-5555

Montana One Call 1-800-551-8344

NEBRASKA

Diggers Hotline of Nebraska 1-800-331-5666

NEVADA

Underground Service Alert of NV 1-800-227-2600

NEW HAMPSHIRE

Dig Safe -- New Hampshire 1-888-344-7233

NEW JERSEY

Garden State Underground Line Locating Service 1-800-272-1000

NEW MEXICO

New Mexico One Call System, Inc. 1-800-321-ALERT

NEW YORK

Underground Facility Protection Organization 1-800-962-7962

New York City Long Island One Call Center 1-800-272-4480

NORTH CAROLINA

North Carolina One Call Center 1-800-632-4949

NORTH DAKOTA

Utilities Underground Location Center 1-800-454-5555

OHIO

Ohio Utilities Protection Service 1-800-362-2764

OKLAHOMA

Call Okie 1-800-522-6543

OREGON

Utility's Underground Location Center 1-800-424-5555

Douglas Utility's Coordinating Council 1-503-673-6676

Josephine Utility's Coordinating Council 1-503-476-6676

Utility's Notification Center 1-800-332-2344

Rogue Basin Utility Coordinating Council 1-503-779-6676

PENNSYLVANIA

Pennsylvania One Call System, Inc. 1-800-242-1776

RHODE ISLAND

Dig Safe -- Rhode Island 1-888-344-7233

SOUTH CAROLINA

Palmetto Utility Protection Service, Inc. 1-800-922-0983

SOUTH DAKOTA

South Dakota One Call 1-800-781-7474

TENNESSEE

Tennessee One Call System 1-800-351-1111

TEXAS

Lone Star Notification Center 1-800-669-8344

Texas Excavation Safety System 1-800-344-8377

Texas One Call System 1-800-245-4545

UTAH

Blue Stakes Location Center 1-800-662-4111

VERMONT

Dig Safe Vermont 1-888-344-7233

VIRGINIA

Miss Utility of Virginia 1-800-522-7001

Miss Utility 1-800-257-7777

Miss Utility of Delmarva 1-800-441-8355

WASHINGTON

Utilities Notification Center 1-800-332-2344

Grays Harbor & Pacific County Utility Coordinating Council 1-206-532-3550

Utilities Underground Location Center 1-800-424-5555

Chelan-Douglas Utility Coord Council 1-509-663-6111

Upper Yakima County Underground Utilities Council 1-800-553-4344

Inland Empire Utility Coordinating Council 1-509-456-8000

Utilities Council of Cowlitz County 1-360-425-2506

Palouse Empire Utility Cord. Council 1-800-822-1974

WASHINGTON, DISTRICT OF COLUMBIA

Miss Utility 1-800-257-7777

WEST VIRGINIA

Miss Utility of West Virginia, Inc. 1-800-245-4848

WISCONSIN

Diggers Hotline, Inc. 1-800-242-8511

WYOMING

Wyoming One Call 1-800-348-1030

West Park Utility Coordinating Council 1-307-587-4800

Converse County Coordinating Council 1-800-562-5561

Fremont County Utility Coord Council 1-800-489-8023

Central Wyoming Utilities Coordinating Council 1-800-759-8035

Albany County Utility Coordinating Council 1-307-742-3615

Southeast WY Utility Coordinating Council 1-307-638-6666

Southwest Wyoming One Call 1-307-362-8888

Utilities Underground Location Center 1-800-454-5555

Carbon County Utility Coordinating Council 1-307-324-6666

Call-In Dig-In Safety Council 1-307-682-9811

CANADA

Alberta: Alberta One Call Location Corp. 1-800-242-3447

British Columbia: BC One Call 1-800-474-6886

Ontario: Ontario One Call Centre Ltd. 1-800-400-2255 or 905-709-1717

Ontario: Waterloo Region Bud System 1800-265-2288