Exhibit 3.15

                                STATE OF ARKANSAS

                               SECRETARY OF STATE

                               W. J. "Bill" McCuen
                               Secretary of State

To All to Whom These Presents Shall Come. Greeting:

      I, Bill McCuen, Secretary of State of the State of Arkansas, do hereby
certify that the following and hereto attached instrument of writing is a true
and perfect copy of

                            ARTICLES OF INCORPORATION

                            OF

                            FLY ASH PRODUCTS, INCORPORATED

                            Original Articles filed:
                            June 2, 1987

                                           In Testimony Whereof, I have hereunto
                                           set my hand and affixed my official
                                           seal. Done at office in the City of
                                           Little Rock, this 8th day of June
                                           1987


                                           -------------------------------------
                                                              Secretary of State


                            ARTICLES OF INCORPORATION

                                       OF

                         FLY ASH PRODUCTS, INCORPORATED

                               FILED JUNE 2, 1987

                               W. J. "Bill" McCuen

                               Secretary of State

                               By:________________

      THE UNDERSIGNED, acting as the incorporator, in order to form a business
corporation for the purposes stated, pursuant to all of the provisions of the
Arkansas Business Corporation Act, ARK. ACTS 1965, No. 576 as amended [codified
as Ark. Stat. Ann. ss. 65-101, et seq. (1980 Repl.)], and the Arkansas
Professional Association Statute [codified as Ark. Stat. Ann. ss. 64-2001, et
seq.,] hereby certifies as follows:

                  I. NAME OF THE CORPORATION

      The name of the corporation is FLY ASH PRODUCTS, INCORPORATED (hereinafter
referred to as the "Corporation").

                  II. DURATION OF CORPORATION

      The period of duration of the Corporation shall be perpetual.

                  III. PURPOSES OF THE CORPORATION

      The primary purpose or purposes for which the Corporation is organized,
the nature of the business of the Corporation and the objects or purposes
proposed to be transacted, promoted or carried on by it are:

      To conduct the sale, both retail and wholesale, and disposal of fuel
      consumption by-products.


      To take, lease, purchase or otherwise acquire, and to own, use, hold,
      sell, convey, exchange, lease, mortgage, work, improve, develop, divide
      and otherwise handle, deal in or dispose of real estate, real property,
      and any interest in or right therein through one or more wholly-owned,
      majority-owned or controlled corporations or other entities as may be
      deemed appropriate, and to otherwise directly engage in the real estate
      business as a principal agent, or broker.

      To take, lease, purchase, or otherwise acquire, and to own, use, hold,
      sell convey, exchange, hire, lease, pledge, mortgage, and otherwise deal
      in or dispose of such personal property, chattels, chattels real, rights,
      easements, privileges, choses in action, notes, bonds, mortgages, and
      securities as may be lawfully acquired, held, or disposed of by the
      Corporation under the law.

      To acquire and take over the whole or any part of the business, property,
      assets, contracts, or liabilities or any firm, person, or other
      corporation engaged in the same or any other business within the scope of
      the purposes described herein; to acquire any property, real or personal,
      necessary or reasonably convenient for the carrying on of such business;
      and generally to do and perform all acts proper or necessary for the
      purposes of such business.

      To engage in any lawful business for the purpose of making a profit either
      in this State or any other state or country.

      The foregoing purposes of the Corporation shall be liberally construed
      both as to objects and powers, and it is hereby expressly and specifically
      provided that the foregoing enumeration of specific powers, and purposes
      of the Corporation shall not be held to limit or restrict in any manner
      the powers of the Corporation conferred by law, whether the same be set
      forth herein or not.

                  IV. AUTHORIZED CAPITAL STOCK

      The aggregate number of shares which the Corporation shall have authority
to issue is One Thousand (1,000) shares of common stock which shall have a par
value of Ten Cents ($.10) per share and shall be equal in all respects.

                  V. PAID IN CONSIDERATION

      The Corporation will not commence business until consideration of the
value of at least $300.00 has been received by the Corporation for the issuance
of its shares.

                  VI. ELIMINATION OF PREEMPTIVE RIGHTS


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      No holder of shares of the Corporation shall be entitled as of right to
subscribe for or purchase any of the Corporation's unissued or treasury shares
of the same class or of other classes, whether now or hereafter authorized, or
any bonds, debentures or other evidences of indebtedness, whether or not
convertible into or exchangeable for shares of any class of the Corporation,
except to the extent, if any, that the Bylaws of the Corporation may provide.

                  VII. ADDITIONAL POWERS AND LIMITATIONS

      A. POWER OF BOARD OF DIRECTORS TO RESTRICT SHARE TRANSFERS: The Board of
Directors of the Corporation shall from time to time in connection with the sale
or issuance of shares of the Corporation have the authority to limit or restrict
the same from sale, assignment, pledge or hypothecation in such manner and
according to such price or terms as the Board of Directors, in its sole
discretion, shall deem fit, so long as any such limitation or restriction shall
be reasonable and provided that any such limitation or restriction shall be
evidenced by a notation to such effect on any certificate evidencing ownership
of such shares issued upon which such limitation or restriction may exist.

      B. POWER TO ENTER PARTNERSHIP: The Corporation, acting through its Board
of Directors, shall be authorized to enter into any general or limited
partnership with any other person, firm or corporation for the purposes of
carrying out any of the objects or purposes of the Corporation.

      C. QUORUM AT SHAREHOLDER MEETINGS: Unless the Bylaws of the Corporation
otherwise provide for a greater number, a quorum at any meeting of the
shareholders of the Corporation shall consist of a majority of the shares
entitled to vote thereat, represented in person or by duly-authorized proxy at
such meeting.

      D. AUTHORIZATION OF BOARD OF DIRECTORS TO REPURCHASE SHARES OF THE
CORPORATION: The Board of Directors of the Corporation shall be authorized as it
deems fit within its discretion to authorize the Corporation to repurchase or
redeem shares of the Corporation whether the same be done from earned surplus or
capital


                                        3


surplus, other than revaluation surplus, of the Corporation, so long as the same
shall otherwise be authorized by law and in conformity with the provisions of
the Articles of Incorporation of the Corporation or any amendment thereof;
provided, however, such provisions shall not be construed as a right of the
Corporation to repurchase or redeem any share of the Corporation without the
consent of the holder of such share unless such share shall have been issued
with a right of repurchase or redemption reserved to the Corporation or pursuant
to any lawful agreement between the Corporation and such shareholder.

      E. INFORMAL ACTION OF THE BOARD OF DIRECTORS: Action taken by a majority
of the Board of Directors without a meeting shall be valid with respect to any
corporate matter as the action of the Board of Directors if, either before or
after such action is taken, all members of the Board of Directors sign and file
with the Secretary of the Corporation for inclusion in the minute book a
memorandum showing the nature of the action taken and their written consent to
the Board of Directors acting informally with respect to such matters, but such
written memorandum shall show whether or not such director approves of the
action to be taken by the Board of Directors so that the Secretary shall note in
the minutes of the Corporation the names of those directors approving the action
of the Board of Directors and the names of those opposing it:

                  VIII. REGISTERED OFFICE AND AGENT OF THE CORPORATION

      The address of the registered office of the Corporation shall be 511
Commerce Street, P.O. Drawer 8597, Pine Bluff, Arkansas 71611. The registered
agent of the Corporation at such address is Donald A. Thomas.

                  IX. NUMBER OF DIRECTORS OF INITIAL BOARD OF DIRECTORS

      The number of directors constituting the Board of Directors of the
Corporation is three (3), and will serve as directors until the first annual
meeting of shareholders or until their successors are duly elected and
qualified.


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      At any annual meeting or special meeting, called for that purpose, of the
shareholders following the time when the shares of the corporation shall become
owned of record by more than three shareholders, the number of directors may be
increased not to exceed ten members.

                  X. INCORPORATOR

      The name and address of the incorporator of the Corporation is:

            NAME                      ADDRESS
            ----                      -------

            Richard M. Grasby         1819 North Fillmore
                                      Little Rock, Arkansas  72207

      IN WITNESS WHEREOF, the undersigned being the Incorporator of the
Corporation has hereunto set his hand this 2nd day of June, 1987.


                                      ------------------------
                                      RICHARD M. GRASBY


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                                 ACKNOWLEDGMENT

STATE OF ARKANSAS )
                  ) ss.
COUNTY OF PULASKI )

      NOW on this day personally appeared before the undersigned Notary Public
within and for the County and State aforesaid, Richard M. Grasby, known to me
personally as the Incorporator who executed the foregoing Articles of
Incorporation of Fly Ash Products, Incorporated, who affirmed that he was of the
age of twenty-one (21) years or more and acknowledged that he had executed the
same for the purposes therein expressed.

      WITNESS my hand and seal in testimony thereof this 2nd day of May, 1987.


                                                  ------------------------------
                                                           Notary Public

[SEAL]

My Commission expires:


- -----------------------


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                                STATE OF ARKANSAS

                               SECRETARY OF STATE

                               W. J. "Bill" McCuen
                               Secretary of State

To All to Whom These Presents Shall Come. Greeting:

      I, Bill McCuen, Secretary of State of the State of Arkansas, do hereby
certify that the following and hereto attached instrument of writing is a true
and perfect copy of

                            CERTIFICATE OF AMENDMENT

                            OF

                            FLY ASH PRODUCTS, INCORPORATED

                            Filed in this office:
                            February 19, 1988

                                           In Testimony Whereof, I have hereunto
                                           set my hand and affixed my official
                                           seal. Done at office in the City of
                                           Little Rock, this 19th day of
                                           February 1988


                                           -------------------------------------
                                                              Secretary of State


                              ARTICLES OF AMENDMENT
                            TO FLY ASH PRODUCTS, INC.
                            ARTICLES OF INCORPORATION

      Fly Ash Products, Inc., does hereby amend its Articles of Incorporation
for the purpose of electing to be governed by the Arkansas Business Corporation
Act of 1987 (Sections 4-27-122 through 4-27-1706 of the Arkansas Code of 1947)
and for the other purposes herein stated:

      FIRST: The name of this corporation shall be Fly Ash Products, Inc.

      SECOND: The following shall be treated as additional amendments to the
Articles of Incorporation:

      (a) The purpose for which the corporation is organized is to conduct the
business of selling and disposing of coal ash.

      (b) The aggregate number of shares which the Corporation shall have
authority to issue is 900 shares of common stock which shall have a par value of
ten cents (.10) per share, each of which shares shall have identical rights and
limitations.

      (c) No holder of shares of the Corporation shall be entitled as of right
to subscribe for or purchase any of the corporation's unauthorized and unissued
shares whether now or hereafter authorized, or any bonds, debentures or other
evidence of indebtedness, whether or not convertible into or exchangeable for
shares of any class of the Corporation.

      (d) The holder of each share of the common stock of the Corporation shall
be entitled to one vote on each matter voted on at a shareholders meeting for
each such share.

      (e) Shares of stock of the Corporation shall be subject to the following
restrictions and limitations on transfer, in addition to any limitations which
may be provided by laws:

            (1) In the event that any shareholder desires to sell, assign,
            transfer, or make any other disposition of any of his shares (the
            "Offering Shareholder") the Offering Shareholder shall give least
            thirty (30) days' notice in writing by registered or certified mail
            to the Corporation and each other registered shareholder setting
            forth the number of shares that the Offering Shareholder desires to
            sell or dispose of together with the specific terms of a bona fide
            offer from a third party which the Offering Shareholder is willing
            to accept. Provided, however, that any transfer by a Shareholder to
            his or her spouse at the time such shares were issued (but not to
            subsequent spouses), to a child, grandchild, father, mother, sister
            or brother or to a trust whose sole beneficiaries are one of this


            designated group, shall not give rise to the option herein provided
            for. Within this thirty (30) day period, the Corporation shall call
            a meeting of the board of directors to which all shareholders shall
            be invited upon not less than five (5) days nor more than ten (10)
            days written notice to all of the directors and such shareholders.
            This meeting shall be held at the Corporation's principal office or
            such other place as may be designated in the notice, during normal
            business hours. At the meeting, the shares of the Offering
            Shareholder shall be offered to the Corporation upon the identical
            terms represented by the bona fide offer of the intended third party
            purchaser. Should the Corporation elect to exercise its option to
            purchase the offered shares, it shall do so not later than ten (10)
            days following the date of such meeting or any adjournment thereof.

            (2) If the Corporation does not elect to purchase all of the shares
            offered for sale by the Offering Shareholder, the nonpurchased
            shares shall be offered for sale and shall be subject to an option
            in favor of the remaining shareholders to purchase all or a
            proportionate share of any such nonpurchased shares. Following the
            thirty (30) day notice period to the Corporation the Offering
            Shareholder shall give at least thirty (30) days additional notice
            in writing by registered or certified mail to the remaining
            shareholders setting forth the identical information contained in
            the original notice to the Corporation of the intended sale or other
            disposition of the offered shares and including a recital of the
            number of such shares, if any, purchased by the Corporation pursuant
            to its option to purchase such offered shares. Each such shareholder
            shall have the right to purchase his proportionate share or up to
            all of the remaining unpurchased shares so offered on like terms as
            the intended sale or disposition by the offering shareholder. A
            remaining shareholder desiring to exercise the option to purchase
            his proportionate share or up to all of the remaining shares shall
            so indicate by a written notice delivered by registered or certified
            mail or delivered in person to the Offering Shareholder and the
            other shareholders of the Corporation which, if mailed, shall be
            postmarked within the thirty (30) day period following the giving of
            such notice by the Offering Shareholder. The term "proportionate
            share" as used in this provision shall mean that portion of the
            shares of the Corporation offered for sale which the shares then
            owned by each of the nonselling shareholders bear to the total of
            the nonoffered shares of the shareholders not proposing to sell any
            part thereof. A stockholder electing to


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            exercise the option may purchase, in addition to his proportionate
            share, any of the offered shares which are not being purchased by
            other offering shareholders by stating in his exercise of the option
            his intention so to do. Should more than one offeree shareholder
            elect to purchase up to all of the unpurchased offered shares and
            one or more other shareholders elect not to so purchase such
            unpurchased offered shares, then the purchasing shareholders shall
            be entitled to purchase the offered and unpurchased shares
            proportionately to their then number of shares of the Corporation
            compared with the number of shares held by the other purchasing
            shareholders.

            (3) If the Corporation or any of the nonoffering shareholders elect
            to purchase any or all of the offered shares, the Offering
            Shareholder shall deliver to the indicated purchaser share
            certificates duly endorsed evidencing such shares accompanied by any
            documents necessary to effect a transfer. Simultaneously with such
            transfer, the Corporation or the purchasing shareholder or
            shareholders shall pay to the Offering Shareholder the entire
            purchase price and/or such evidence of debt and cash as may have
            been the basis of the proposed sale terms accepted by the
            Corporation and/or the purchasing shareholders.

            (4) If after having first offered the shares intended for sale by
            the Offering Shareholder to the Corporation and to the remaining
            shareholders in the manner herein specified there remain any of the
            offered shares which have not been purchased by the Corporation or
            the remaining shareholders, then within thirty (30) days following
            expiration of the time for exercise of the option in favor of the
            remaining shareholders, the Offering Shareholder may sell such
            shares to the intended purchaser for the price and on the terms
            originally proposed to the Corporation and the remaining
            shareholders, but such shares in the hands of the purchaser shall
            continue to be subject to the options retained herein with respect
            to such shares in connection with any subsequent transfer.

            (5) All certificates evidencing shares shall bear on the face, in
            the margin or as a legend the following language:

                  "The shares evidenced by this certificate are subject to the
                  restrictions and limitations on the transfer thereof set forth
                  in the Articles of Incorporation of the issuing Corporation."

            (6) No restriction contained herein shall be binding or effective
            against any pledgee of the outstanding shares of the Corporation at


                                        3


            the time of this amendment, but shall become effective with respect
            to such shares when they have been acquired by the pledgee or any
            purchaser thereof in the exercise of any power of sale or
            foreclosure with respect to such pledge.

      THIRD: The amendments herein contained shall constitute an entire
restatement of the Articles of Incorporation of this Corporation and no
provision of the original Articles of Incorporation which in any manner alter,
conflict with, derogate from or limit any of the provisions hereof or any right
granted to corporations, generally, under the provisions of the Arkansas
Business Corporation Act of 1987, shall be deemed applicable to this
Corporation.

      FOURTH: This amendment was adopted at meeting of the shareholders of the
Corporation duly called and held at which a proper quorum of the shareholders
was present. At the time of the meeting of the shareholders there were nine
hundred (900) shares of the corporation's common stock outstanding of which 900
shares were cast for this amendment. The number of votes cast for this amendment
by the only class of stock of the Corporation authorized to vote thereon was
sufficient for approval.

      FIFTH: The Board of Directors of the Corporation shall have authority to
adopt any Bylaws, not in contravention of the law, which they may deem
appropriate for the governance of the affairs of the Corporation.

      SIXTH: The address of the registered office of the Corporation shall be
511 Commerce Street, P.O. Drawer 8597, Pine Bluff, Arkansas 71611.

      SEVENTH: The registered agent of the Corporation shall be Donald A.
Thomas, 511 Commerce Street, Pine Bluff, Arkansas 71601.

      EIGHTH: No officer or director of the Corporation shall be liable to the
shareholders of the Corporation for breach of his or her fiduciary duty as such
director or officer except:

      (a) For any breach of the directors or officers duty of loyalty to the
Corporation or its stockholders;


                                        4


      (b) For acts or omissions not in good faith or which involve intentional
misconduct or a knowing violation of law;

      (c) Under Section 4-27-833 of the Arkansas Business Corporation Act of
1987;

      (d) For any transaction from which the director derived an improper
personal benefit; or

      (e) For any action, omission, transaction or breach of a director's or
officer's duty creating any third party liability to any person or entity other
than the Corporation or its shareholders.

      IN WITNESS WHEREOF, the undersigned officers of the Corporation have
hereunto placed the name of the Corporation as they are thereunto duly
authorized this 15th day of February, 1988.

                                          FLY ASH PRODUCTS, INC.

                                          By:
                                             -------------------------------
                                                  President

ATTEST:

- ----------------------
     Secretary


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