<PAGE>

                                                                   Exhibit 10.15

                             SEPARATION AGREEMENT

     THIS SEPARATION AGREEMENT ("Separation Agreement"), is made and entered
into as of February 1, 2000, by and between RICHARD S. GRANVILLE, III, an
individual residing in the State of Georgia ("Granville"), and GRACE
DEVELOPMENT, INC., a Colorado corporation (the "Company").

                                  WITNESSETH:

     WHEREAS, Granville has been serving as Chief Executive Officer and a member
of the Board of Directors of the Company;

     WHEREAS, Granville and the Company agree that Granville's service as Chief
Executive Officer and a member of the Board of Directors of the Company should
be ended; and

     WHEREAS, Granville and the Company desire to resolve fully and finally all
issues between them that arise or may arise out of the cessation of Granville's
service with the Company.

     NOW THEREFORE, in consideration of the premises and mutual promises herein
contained and other good and valuable consideration, the receipt and sufficiency
of which are hereby acknowledged, it is agreed as follows:

                                  AGREEMENT:

1.   Resignation. Granville and the Company agree that effective as of 5:00 p.m.
     -----------
Eastern Time on February 1, 2000 (the "Termination Date"), Granville shall, and
hereby does, voluntarily and permanently resign his positions as Chief Executive
Officer and as a member of the Board of Directors and member of any committee
of, or for, the Company and each of its subsidiaries and affiliates.
Concurrently herewith, Granville is executing and delivering to the Company a
letter of resignation in the form attached as Exhibit 1 hereto (the "Resignation
                                              ---------
Letter").  Each of the Company's obligations under this Separation Agreement is
subject to the execution and delivery to the Company by Granville of this
Separation Agreement and the Resignation Letter.  This Separation Agreement
shall be effective upon such execution and delivery by Granville and execution
of this Separation Agreement by the Company.

2.   Payments and Benefits.
     ---------------------

     (a)  Severance Fee.  On March 1, 2000 and June 1, 2000 the Company shall
pay to Granville two cash severance payments in equal installments of $50,000
each for a total of $100,000.00. Granville shall be responsible for the payment
of all federal, state and local payroll or other employment taxes with respect
to such severance payments. In addition there are currently outstanding expenses
and a charge due to both to Granville and the company in which it is agreed that
upon confirmation of these charges both parties will remedy and due balances on
or before Mach 31 2000.
<PAGE>

     (b)  Personal Guarantees; Company Property; Credit Cards. Promptly
following the Termination Date, Granville will (i) return all Company credit
cards previously provided to Granville; (ii) return all personal property owned
by the Company that is in Granville possession and control, and (iii) deliver to
the Company a listing of all obligations of the Company for which Granville has
provided personal guarantees or other financial assurances. The Company will use
its best efforts to effect the release of Granville from any such obligations,
such releases to be effected not later than December 31, 2000. Granville
acknowledges and agrees that any personal charges made on credit cards of the
Company will be reimbursed to the Company by deducting such amounts due and
owing from any severance payments to be made pursuant to Section 2(a).

     (c)  No Other Payments or Benefits. Granville acknowledges and agrees that,
other than the payments described specifically in this Separation Agreement,
Granville shall not be entitled to receive on or after the Termination Date any
other benefits, payments, bonuses, severance, termination benefits or
compensation of any kind or for any reason, specifically including but not
limited to any earned or unearned wages, bonuses, payments, benefits, commission
payments, stock options (whether vested or unvested), stock or any other
benefit, payment or compensation of any kind or from any source; provided,
                                                                 --------
however, that if, as and to the extent that Granville and the Company contract
-------
for the provision of consulting services to the Company by Granville, Granville
and the Company will agree with respect to appropriate compensation therefor
(the "Future Consulting Fees").

3.   No Derogatory Statements.
     ------------------------

     (a)  Granville further agrees that, as part of the consideration for this
Separation Agreement, he will not, directly or indirectly, in any capacity or
manner, take any action or cause any action to be taken which would be
detrimental to the interests of the Company, its subsidiaries or affiliates and
their respective officers, directors, agents and employees, including, without
limitation, making, causing, encouraging or assisting to be made any statements,
comments or remarks, whether oral, verbal, in writing or electronically
transmitted, which might reasonably be considered to be derogatory, defamatory
or critical of, or negative towards, or to malign, harm, defame, disparage or
damage the reputation and good name of, the Company, its subsidiaries or
affiliates, or their respective officers, directors, agents and employees.

     (b)  The Company further agrees that, as part of the consideration for this
Separation Agreement, it will not, directly or indirectly, in any capacity or
manner, make, cause, encourage or assist to be made any statements, comments or
remarks, whether oral, verbal, in writing or electronically transmitted, which
might reasonably be considered to be derogatory, defamatory or critical of, or
negative towards, or to malign, harm, defame, disparage or damage the reputation
and good name of, Granville.

4.   Compliance with Securities Laws. Granville covenants and agrees to continue
     -------------------------------
to comply with the provisions of the Securities Act of 1933, as amended, the
Securities Exchange Act of 1934, as amended, applicable state "blue sky" laws
and all rules and regulations promulgated thereunder (collectively, the
"Securities Laws") as such laws, rules and regulations apply to him.

                                                      /s/ R. G.
                                                      --------------------------
                                                      Initials

                                       2
<PAGE>

Granville acknowledges that, as of the date hereof, he is in possession of
material, nonpublic information regarding the Company, and agrees that he will
refrain from the purchase and sale of any of the Company's securities and from
disclosing such information to any other person, unless and until the Company,
or its counsel, shall advise him that such restriction no longer applies.
Granville also acknowledges that he has received copies of the Company's
proposed policy with respect to compliance with the Securities Laws and related
rules and regulations, and agrees to abide by such policy and the rules and
regulations referenced therein.

5.   Nondisclosure.  Granville represents, covenants and agrees that he will
     -------------
keep the terms and facts of this Separation Agreement, and negotiations and
discussions related hereto, completely and strictly confidential, and that he
will not, directly or indirectly, in any capacity or manner, discuss with, or
disclose to, anyone, including, without limitation, reporters and analysts, any
information concerning this Separation Agreement, the matters contemplated
herein or matters related to Granville's service with or departure or
resignation from the Company, or any negotiations and discussions related hereto
or thereto; provided, however, that Granville may disclose information regarding
this Separation Agreement in confidence to his spouse, accountant, tax advisor
and legal counsel, after obtaining the agreement of any such person to also
maintain the confidentiality of such information in accordance herewith, and
provided further that if Granville is compelled as a matter of law to disclose
such information, Granville will promptly notify the Company in order to permit
the Company to seek a protective order or take other appropriate action with
respect to such disclosure, and Granville will cooperate in the Company's
efforts to obtain such protective order or other reasonable assurance that
confidential treatment will be accorded such information, and if such protective
order is not obtained, Granville may disclose to the party or authority
compelling such disclosure such part of such information as is required by law
to be disclosed. Granville will immediately refer to Mr. James Blanchard and/or
the Company's investor relations department (without further comments or
response) all contacts, questions and requests for information, from analysts,
reporters or otherwise, regarding the Company or Granville's resignation,
employment with or departure from the Company. Notwithstanding the foregoing,
Granville and the Company agree that a mutually agreeable press release
announcing Granville's resignation as Chief Executive Officer and a member of
the Board of Directors of the Company shall be issued by the Company as soon as
practicable after the execution and delivery of this Separation Agreement.

6.   Releases.
     --------

     (a)  General Release of Claims.  As a material inducement to the Company to
enter into this Separation Agreement, and in partial exchange for the
consideration recited herein, Granville hereby irrevocably and unconditionally
releases, acquits and forever discharges the Company and each of the Company's
owners, stockholders, predecessors, successors, assigns, agents, directors,
officers, employees, representatives, attorneys, divisions, subsidiaries,
affiliates (and agents, directors, officers, employees, representatives and
attorneys of such divisions, subsidiaries and affiliates), and all persons
acting by, through, under or in concert with any of them (collectively,
"Releasees"), or any of them, from any and all charges, complaints, claims,
liabilities, obligations, promises, agreements, controversies, damages, actions,
causes of action,

                                                       /s/ R. G.
                                                      -----------------------
                                                      Initials

                                       3
<PAGE>

suits, rights, demands, costs, losses, debts and expenses (including attorney's
fees and costs actually incurred), of any nature whatsoever pertaining to
Granville's service with or resignation or separation from the Company, whether
known or unknown, which Granville now has, owns or holds, or claims to have, own
or hold, or which Granville at any time hereafter may have, own or hold, or
claim to have, own or hold, against each or any of the Releasees (collectively,
"Claims"), except for the duties and obligations expressly assumed by the
Company in this Separation Agreement. Granville acknowledges and agrees that he
is releasing and giving up any right which he may have under any contract
entered with the Company, and under any federal or state law or political
subdivision thereof, including the Age Discrimination in Employment Act, which
prohibits age discrimination in employment; Title VII of the Civil Rights Act of
1964, which prohibits discrimination in employment based on race, color,
national origin, religion or sex; the Equal Pay Act, which prohibits paying men
and women unequal pay for equal work; or any other federal, state or local laws
or regulations prohibiting employment discrimination. Granville also
acknowledges and agrees that he is releasing and giving up any claims he has or
may have had for wrongful discharge. Notwithstanding anything herein to the
contrary, nothing herein shall in any way affect Granville's right to receive
Future Consulting Fees.

     (b)  No Breach. Granville agrees that the Company has not breached any oral
or written employment or other agreement, contract or understanding, including,
without limitation, the Employment Agreement, which exists or may have existed
between Granville and the Company with respect to any aspect of Granville's
service with, or separation or resignation of employment from, the Company or
with respect to any other matter whatsoever as of the time of execution of this
Separation Agreement.  Granville further agrees that the Company has not
violated any law, statute, rule, regulation or ordinance of the United States or
of any state or political subdivision thereof, including, without limitation,
the Age Discrimination in Employment Act, with respect to any aspect of
Granville's service with, or separation or resignation of employment from, the
Company or with respect to any other matter whatsoever as of the time of
execution of this Separation Agreement.

     (c)  No Complaints or Charges Filed. Granville represents that he has not
filed any complaints or charges against the Company or its subsidiaries or
affiliates with any local, state or federal agency or court related to
Granville's service with or separation or resignation from the Company, that
Granville will not do so at any time hereafter, relating to any action or events
that predate the date hereof, and that if any such agency or court assumes
jurisdiction of any such complaint or charge against the Company or its
subsidiaries or affiliates on behalf of Granville, Granville will request such
agency or court to withdraw from the matter.

     (d)  Acknowledgement of Waiver of All Claims. Granville expressly
acknowledges that this Separation Agreement is intended to include in its
effect, without limitation, all Claims which Granville does not know or suspect
to exist in Granville's favor at the time of execution hereof,


                                                       /s/ R. G.
                                                      -----------------------
                                                      Initials

                                       4
<PAGE>

and that this Separation Agreement contemplates the extinguishment of any such
Claim or Claims, as they may pertain to Granville's service with or separation
or resignation from the Company.

          (e)  No Admission.  This Separation Agreement shall not in any way be
construed as an admission by either party of any wrongful conduct whatsoever
against any person or party, and both parties specifically disclaim any
liability to or wrongful conduct against any other person or party.  It is
acknowledged by each party that this Separation Agreement is mutually sought and
for the benefit of each to resolve all disputed claims and controversies.

7.   Confidentiality and Non-solicitation.  In partial exchange for the
     ------------------------------------
consideration recited herein, Granville hereby covenants and agrees as follows:

     (a)  Granville shall not disclose to any person or entity or use, at any
time, any information not in the public domain or generally known in the
industry, in any form, acquired by Granville while employed by the Company or
any predecessor to the Company's business, and relating to the Company, its
subsidiaries or affiliates, including but not limited to information regarding
customers, vendors, suppliers, trade secrets, training programs, manuals or
materials, technical information, contracts, systems, procedures, mailing lists,
know-how, trade names, improvements, price lists, financial or other data
(including the revenues, costs or profits associated with any of the Company's
services), business plans, code books, invoices and other financial statements,
computer programs, software systems, databases, discs and printouts, plans
(business, technical or otherwise), customer and industry lists, correspondence,
internal reports, personnel files, sales and advertising material, telephone
numbers, names, addresses or any other compilation of information, written or
unwritten, which is or was used in the business of the Company or any
subsidiaries or affiliates thereof. Granville agrees and acknowledges that all
of such information, in any form, and copies and extracts thereof, are and shall
remain the sole and exclusive property of the Company.  On or before the
Termination Date, Granville shall return to the Company the originals and all
copies of any such information provided to or acquired by Granville in
connection with the performance of his duties for the Company, and shall return
to the Company all files, correspondence and/or other communications received,
maintained and/or originated by Granville during the course of his employment.

     (b)  Granville covenants that he will not, directly or indirectly, whether
for his own account or the account of any other person or entity for a period
commencing on the Termination Date and ending on December 31, 2001, solicit,
employ or otherwise engage as an employee, independent contractor or otherwise,
any person who is an employee, or is acting as an employee, independent
contractor or agent of, the Company, its subsidiaries or affiliated companies,
or in any manner induce or attempt to induce any such employee, independent
contractor or agent of the Company, its subsidiaries or affiliated companies, to
terminate his or her employment with the Company, its subsidiaries or affiliated
companies.



                                                       /s/ R. G.
                                                      -----------------------
                                                      Initials

                                       5
<PAGE>

     (c)  The parties have entered into this Separation Agreement in good faith
and for the reasons set forth in the recitals hereto and assume that this
Section is legally binding.  If for any reason, this Section is not binding
because of its term, then the parties agree that this Section shall be deemed
effective for the longest period of time as may be legally enforceable. The
parties hereto agree that: (i) the covenants and agreements of Granville
contained in this Section are reasonably necessary to protect the interests of
the Company, (ii) the period of restriction contained in this Section is fair
and reasonable and is not greater than is necessary for the protection of the
Company in light of the substantial harm that the Company will suffer should
Granville breach any of the provisions of said covenants or agreements; (iii)
the covenants and agreements of Granville contained in this Section are material
inducements for the Company to enter into this Separation Agreement; (iv) the
nature, kind and character of the activities Granville is prohibited to engage
in are reasonable and necessary to protect the Company and (v) the Company's and
its subsidiaries' business is international in scope, and the Company and its
subsidiaries compete with other businesses that are or could be located
throughout North America.  Granville hereby represents and warrants to the
Company that, by reason of the abilities and experience of Granville, the
enforcement of the covenants and agreements set forth in this Section will not
prevent Granville from obtaining other suitable employment or earning a
livelihood in his profession.

     (d)  Granville acknowledges that the rights and privileges granted to the
Company in this Section are of special and unique character, which gives them a
peculiar value, the loss of which may not be reasonably or adequately
compensated for by damages in an action of law, and that a breach thereof by
Granville of this Section will cause the Company great and irreparable injury
and damage. Accordingly, Granville hereby agrees that the Company shall be
entitled to remedies of injunction, specific performance or other equitable
relief to prevent a breach of this Section by Granville, without any requirement
on the part of the Company to prove actual damages or to post or secure any bond
(which requirements are hereby waived). This provision shall not be construed as
a waiver of, and shall be in addition to, any other rights or remedies the
Company may have for damages or otherwise.

8.   Voluntary Agreement. Granville represents and agrees that he has thoroughly
     -------------------
considered all aspects of this Separation Agreement and that he has been advised
by the Company that he should discuss any and all aspects of this matter with an
attorney chosen by Granville, that Granville has carefully read and fully
understands all of the provisions of this Separation Agreement and that
Granville is voluntarily entering into this Separation Agreement of his own free
will, without coercion, and in exchange for the consideration recited herein.
Granville further understands that the Company is relying on this and all other
representations he has made herein.

9.   Indemnification.
     ---------------

     (a)  As a further material inducement to the Company to enter into this
Separation Agreement, Granville hereby agrees to indemnify and hold the Company
harmless from and against all loss, cost, damage or expense, including, without
limitation, attorneys' fees, incurred


                                                        /s/ R. G.
                                                      --------------------------
                                                      Initials

                                       6
<PAGE>

by the Company, arising out of (i) any breach or alleged breach of this
Separation Agreement by Granville, or (ii) Granville's service with the Company.

     (b)  As a further material inducement to Granville to enter into this
Separation Agreement, the Company hereby agrees to indemnify and hold Granville
harmless from and against all loss, cost, damage or expense, including, without
limitation, attorneys' fees, incurred by Granville, arising out of (i) any
breach or alleged breach of this Separation Agreement by the Company, or (ii)
Granville's service with the Company.

10.  No Other Representations.  Granville represents and acknowledges that in
     ------------------------
executing this Separation Agreement, Granville does not rely and has not relied
upon any representation or statements made by the Company or the Releasees or by
any of the Company's or Releasees' agents, representatives or attorneys with
regard to the subject matter, basis or effect of this Separation Agreement or
otherwise, except as set out herein.

11.  Successors.  This Separation Agreement shall be binding upon Granville and
     ----------
the Company and upon their respective heirs, administrators, representatives,
executors, successors and assigns, and shall enure to the benefit of Granville,
the Company and the Releasees and Granville Releasees and each of them, and to
their respective heirs, administrators, representatives, executors, successors
and assigns.  This Separation Agreement is personal to Granville, and Granville
may not assign or transfer any interests in, or rights or benefits under, this
Separation Agreement.

12.  Review; Revocation.  Granville may revoke this Separation Agreement within
     ------------------
seven (7) days after Granville's signing it, as evidenced by the date set forth
on the signature page hereof.  Revocation can be made by delivering a written
notice of revocation to Mr. James Blanchard, 1690 Chantilly Drive, Atlanta,
Georgia  30324.  For such revocation to be effective, written notice must be
received by Mr. Blanchard no later than 5:00 p.m. Eastern Time on the seventh
(7th) day after Granville signs this Separation Agreement, as evidenced by the
date set forth on the signature page hereof.  If Granville revokes this
Separation Agreement, it shall not be effective or enforceable and Granville
will not receive the benefits, payment or rights described herein and shall
immediately return or repay to the Company in full any benefits, payments or
property described herein that he may already have received.

13.  Notices.  Any notice required or permitted to be given under this
     -------
Separation Agreement shall be sufficient if in writing and if delivered by hand
or by certified or registered mail or by a nationally recognized overnight
delivery service, postage or other charges pre-paid, and addressed to:  Richard
S. Granville, III, at the address set forth in the Company's records (if such
notice is addressed to Granville), or to Mr. James Blanchard, 1690 Chantilly
Drive, Atlanta, Georgia  30324 (if such notice is addressed to the Company), or
such other address as may be designated by a party hereto in written notice to
the other party hereto.  Such notice shall be deemed to have been given or made
on the date of delivery, if delivered by hand, or on the next following date if
sent by mail or overnight delivery service.


                                                        /s/ R. G.
                                                      --------------------------
                                                      Initials

                                       7
<PAGE>

14.  Default.  In the event of a default or breach by Granville of this
     -------
Separation Agreement, then the payments, conveyances and benefits to or for the
benefit of Granville under Section 2 hereof, shall thereupon cease and be
terminated (and this Separation Agreement shall otherwise remain in full force
and effect).  In addition, the Company shall have the right to pursue (i) such
legal remedies as may be available to it to recover from Granville any damages
suffered by the Company, including attorneys' fees, as a result of such default
or breach, and (ii) any equitable remedy or action, including injunctive relief,
as may be appropriate under the circumstances to protect the Company against or
from such default or breach, or continuation thereof.

15.  Choice of Law; Attorneys' Fees.   This Separation Agreement is made and
     ------------------------------
entered into in the State of Georgia and shall, in all respects, be interpreted,
enforced and governed under the laws of said State, without regard for the
principles of conflicts of laws thereof. Any action or proceedings brought by a
party seeking to enforce any provisions of, or based upon any right arising out
of, this Separation Agreement may be brought against any of the parties hereto
in the courts of the State of Georgia or, if it has or can acquire jurisdiction,
in a United States District Court for the State of Georgia, and each of the
parties consents to the jurisdiction of such courts (and of the appropriate
appellate courts) in any such action or proceeding and waives any objection to
venue laid therein.  If legal action is commenced by either party to enforce or
defend its rights under this Separation Agreement, the prevailing party in such
action shall be entitled to recover its costs and reasonable attorneys' fees in
addition to any other relief granted.

16.  Miscellaneous.  The language of all parts of this Separation Agreement
     -------------
shall, in all cases, be construed as a whole, according to its plain meaning,
and not strictly for or against any of the parties, and rules of interpretation
or construction of contracts that would construe any ambiguity against the
draftsman shall not apply.  Should any provision of this Separation Agreement be
declared or be determined by any court to be illegal or invalid, the validity of
the remaining parts, terms or provisions shall not be affected thereby and said
illegal or invalid part, term or provision shall be deemed not to be part of
this Separation Agreement. As used in this Separation Agreement, the singular or
plural number shall be deemed to include the other whenever the context so
indicates or requires.  This Separation Agreement may be executed in two or more
counterparts, each of which shall for all purposes be deemed to be an original
but each of which, when so executed, shall constitute but one and the same
instrument.  This Separation Agreement sets forth the entire agreement between
the parties hereto and fully supersedes any and all prior agreements or
understandings between the parties hereto pertaining to the subject matter
hereof. This Separation Agreement may not be changed orally, but only by an
instrument in writing signed by the party against whom enforcement of any
waiver, change, modification, extension or discharge is sought.  The section and
paragraph headings contained in this Separation Agreement are for convenience of
reference, and shall not limit or control, or be used to construe, the meaning
of any provision herein.  Any delay or omission by any party hereto in
exercising any right hereunder shall not operate as a waiver of such right.

PLEASE READ CAREFULLY.  THIS SEPARATION AGREEMENT INCLUDES A RELEASE OF ALL
KNOWN AND UNKNOWN CLAIMS.


                                                        /s/ R. G.
                                                      --------------------------
                                                      Initials

                                       8
<PAGE>

     WHEREFORE, to signify their agreement to the terms of this Separation
Agreement, which consists of 11 typewritten pages, not including exhibits
hereto, each of the parties hereto have executed this Separation Agreement on
the date set forth immediately above such party's signature which appears below.


     EXECUTED this 1st day of March 2000.

                                            /s/ Richard S. Granville, III
                                            -----------------------------------
                                            Richard S. Granville, III

Notary:______________________________
My Commission Expires:_______________

     EXECUTED this 1st day of March 1999.


                                        GRACE DEVELOPMENT, INC.
                                        By: /s/ James M. Blanchard
                                           ------------------------------------
                                        Name:  James M. Blanchard
                                        Title: President

Notary: /s/ Glenda Abbott
       -------------------------------
My Commission Expires: 09-03-2001
                      ----------------


           GLENDA ABBOTT
NOTARY PUBLIC GWINNETT COUNTY GEORGIA
MY COMMISSION EXPIRES AUGUST 03 2001


                                                      __________________________
                                                      Initials

                                       9
<PAGE>

                                   EXHIBIT 1

                                  Resignation
                                  -----------



                                                        /s/ R. G.
                                                      --------------------------
                                                      Initials

                                       10
<PAGE>

                                  Resignation
                                  -----------


The Board of Directors
Grace Development, Inc.
1690 Chantilly Drive
Atlanta, Georgia 30324

Gentlemen:

     The undersigned, Richard S. Granville III, hereby resigns from any and all
positions held by the undersigned as a director, Chairman of the Board of
Directors and member of any committee of Grace Development, Inc., a Colorado
corporation (the "Company"), and each of the subsidiaries and affiliates of the
Company, such resignation to be effective as of 5:00 p.m. Eastern Time on
February 1, 2000.

     EXECUTED and dated as of this 1st day of February 2000.


                                    /s/ Richard S. Granville, III
                                    ----------------------------------
                                    Richard S. Granville, III



                                                        /s/ R. G.
                                                      --------------------------
                                                      Initials

                                       11