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                                                                 Exhibit 3(A)



                            CERTIFICATE OF AMENDMENT

                                       OF

                     RESTATED CERTIFICATE OF INCORPORATION

                                       OF

                      ROLLINS ENVIRONMENTAL SERVICES, INC.

                   Adopted in accordance with the provisions           
                 of Section 242 of the General Corporation Law
                            of the State of Delaware

         I, JOHN W. ROLLINS, JR., Senior Vice Chairman of the Board of Rollins
Environmental Services, Inc., a corporation existing under the laws of the
State of Delaware, do hereby certify as follows:

         FIRST: That the Restated Certificate of Incorporation of said
corporation be amended as follows:

               "FIRST: The name of the Corporation is Laidlaw Environmental
Services, Inc.

         SECOND: That such amendment has been duly adopted by the affirmative
vote of the holders of a majority of the stock entitled to vote in accordance
with the provisions of Section 242 of the General Corporation Law of the State
of Delaware.

         THIRD: That the effective time of this Certificate of Amendment of
Restated Certificate of Incorporation shall be upon filing with the Secretary
of State of the State of Delaware.

         IN WITNESS WHEREOF, I have signed this Certificate this 13th day of
May, 1997.

                                              /s/ John W. Rollins, Jr.
                                              --------------------------------- 
                                              Senior Vice Chairman of the Board

ATTEST:



/s/  Klaus M. Belehoubek
------------------------
Assistant Secretary


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                      RESTATED CERTIFICATE OF INCORPORATION

                                       OF

                      ROLLINS ENVIRONMENTAL SERVICES, INC.


      It is hereby certified that:

      1.    (a)     The present name of the corporation (hereinafter called the
"Corporation") is Rollins Environmental Services, Inc.

            (b)     The name under which the Corporation was originally 
incorporated is Rollins Environmental Services, Inc., and the date of filing the
original Certificate of Incorporation of the Corporation with the Secretary of
the State of Delaware is September 29, 1978.

      2.    The Restated Certificate of Incorporation of the Corporation is
hereby amended by striking out Article FOURTH and SEVENTH thereof and by
substituting in lieu thereof new Articles which are set forth in the Restated
Certificate of Incorporation hereinafter provided for.

      3.    The provisions of the Restated Certificate of Incorporation of the
Corporation as heretofore amended and/or supplemented, and as herein amended,
are hereby restated and integrated into the single instrument which is
hereinafter set forth, and which is entitled Restated Certificate of
Incorporation of Rollins Environmental Services, Inc. without any further
amendments other than amendments herein certified and without any discrepancy
between the provisions of the Restated Certificate of Incorporation as
heretofore amended and supplemented and the provisions of the said single
instrument hereinafter set forth.

      4.    The amendments and the restatement of the Restated Certificate of
Incorporation herein certified have been authorized by the Board of Directors of
the Corporation and duly adopted by the stockholders in accordance with the
provisions of Section 242 and Section 245 of the General Corporation Law of the
State of Delaware.

      5.    The effective time of the Restated Certificate of Incorporation and
of the amendments herein certified shall be upon filing with the Secretary of
State of the State of Delaware.

      6.    The Restated Certificate of Incorporation of the Corporation, as
amended and restated herein, shall at the effective time of this Restated
Certificate of Incorporation, read as follows:


RESTATED CERTIFICATE OF INCORPORATION
OF



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ROLLINS ENVIRONMENTAL SERVICES, INC.

      FIRST:   The name of the Corporation is ROLLINS ENVIRONMENTAL SERVICES, 
INC.

      SECOND:  The registered office of the Corporation is to be located at One
Rollins Plaza, 2200 Concord Pike, New Castle County, Wilmington, Delaware 19803.
The name of its registered agent at that address is Rollins Environmental
Services, Inc.

      THIRD:   The purpose of the Corporation is to engage in any lawful act or
activity for which a Corporation may be organized under the General Corporation
Law of Delaware.

      FOURTH:  The total number of shares of stock which the Corporation is
authorized to issue is three hundred fifty-one million (351,000,000) shares,
divided into two classes. The designation of each class, and the par value of
the shares of each class are as follows:

<TABLE>
<CAPTION>
                  CLASS             NO. OF SHARES    PER SHARE PAR VALUE
                  -----             -------------    -------------------
                  <S>               <C>              <C>            
                  Common            350,000,000      $1.00 per share
                  Preferred         1,000,000        $1.00 per share
</TABLE>

                  All preferred stock authorized for issuance by the Corporation
                  may be issued in series or without series from time to time
                  with the designations, preferences, and relative,
                  participating, optional or other special rights of the class
                  or series of the class fixed by resolution or resolutions of
                  the Board of Directors. Such resolutions may also provide for
                  the convertibility of the preferred stock or any series
                  thereof into any other classes of stock of the company,
                  including the common stock, upon such terms and rations as
                  shall be determined by the Board of Directors.

      FIFTH:   Special meetings of the stockholders may be called at any time by
the Chairman of the Board of Directors, the President or the Chairman of the
Executive Committee of the Board of Directors and not by any other person. No
action shall be taken by the stockholders except at an annual or special meeting
of stockholders and stockholders may not act by written consent.

      SIXTH:   The following provisions are inserted for the management of the
business and for the conduct of the affairs of the Corporation, and for further
definition, limitation and regulation of the powers of the Corporation and of
its directors and stockholders:

            (1) Election of directors need not be by ballot unless the by-laws
so provide.

            (2) The Board of Directors shall have power without the assent or
vote of the stockholders to make, alter, amend, change, add to or repeal the
by-laws of the 



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Corporation; to fix and vary the amount to be reserved for any proper purpose;
to authorize and cause to be executed mortgages and liens upon all or any part
of the property of the Corporation; to determine the use and disposition of any
surplus or net profits; and to fix the times for the declaration and payment of
dividends. The stockholders may make, alter or repeal any by-law whether or not
adopted by them, provided however, that any such additional by-laws, alterations
or repeal may be adopted only by the affirmative note of the holders of 75% or
more of the outstanding shares of capital stock of the Corporation entitled to
vote generally in the election of directors (considered for this purpose as one
class), unless such additional by-laws, alterations or repeal shall have been
recommended to the stockholders for adoption by a majority of the Board of
Directors, in which event such additional by-laws, alterations or repeal may be
adopted by the affirmative vote of the holders of a majority of the outstanding
shares of capital stock of the Corporation entitled to vote generally in the
election of directors (considered for this purpose as one class).

            (3) The directors in their discretion may submit any contract or act
for approval or ratification at any annual meeting of the stockholders or at any
meeting of the stockholders called for the purpose of considering any such act
or contract, and any contract or act that shall be approved or be ratified by
the vote of the holders of a majority of the stock of the Corporation which is
represented in person or by proxy at such meeting and entitled to vote thereat
(provided that a lawful quorum of stockholders be there represented in person or
be proxy) shall be as valid and as binding upon the Corporation and upon all the
stockholders as though it had been approved or ratified by every stockholder of
the Corporation, whether or not the contract or act would otherwise be open to
legal attack because of directors' interest, or for any other reason.

            (4) In addition to the powers and authorities hereinbefore or by
statute expressly conferred upon them, the directors are hereby empowered to
exercise all such powers and do all such acts and things as may be exercised, or
done by the Corporation; subject, nevertheless, to the provisions of the
statutes of Delaware, of this Certificate, and to any by-laws from time to time
made by the stockholders; provided, however, that no by-laws so made shall
invalidate any prior act of the directors which would have been valid if such
by-laws had not been made.

      SEVENTH: The property and business of this corporation shall be managed by
a Board of up to ten (10) directors. The directors shall be divided into three
classes. The first class (Class I) shall consist of four (4) directors and the
term of office of such class shall expire at the Annual Meeting of Stockholders
in 1998. The second class (Class II) shall consist of three (3) directors and
the term of office of such class shall expire at the Annual Meeting of
Stockholders in 1999. The third class (Class III) shall consist of three (3)
directors and the term of office of such class shall expire at the Annual
Meeting of Stockholders in 2000. At each annual election, commencing at the next
Annual Meeting of Stockholders in 1998, the successors of the class of directors
whose term expires at that time shall be elected to hold office for the term of
three years to succeed those whose term expires, so that the term of office of
one class of directors shall expire in each year. Each director shall be elected
and qualified, or until his death or until he shall resign. Directors need not
be stockholders nor residents of the State of Delaware.


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            Notwithstanding any of the provisions of this Certificate of
Incorporation or the by-laws of the Corporation (and notwithstanding the fact
that some lesser percentage may be specified by law, this Certificate of
Incorporation or the by-laws of the Corporation), any director or the entire
Board of Directors of the Corporation may be removed at any time, but only for
cause, and only at a meeting of the stockholders called for that purpose by the
affirmative vote of the holders of 75% or more of the shares of the Corporation
entitled to vote at an election of directors.

            Nominations for the election of directors may be made by the Board
of Directors or by any stockholder entitled to vote for the election of
directors. Such nominations shall be made by notice in writing, delivered or
mailed by first class United States mail, postage prepaid, to the secretary of
the Corporation not less than 14 days nor more than 50 days prior to any meeting
of the stockholders called for the election of directors; provided, however,
that if less than 21 days' notice of the meeting is given to stockholders, such
written notice shall be delivered or mailed, as prescribed, to the Secretary of
the Corporation not later than the close of business on the seventh day
following the day on which notice of the meeting was mailed to stockholders.
Notice of nominations which are proposed by the Board of Directors shall be
given by the Chairman on behalf of the Board.

            Each such notice shall set forth (i) the name, age, business address
and, if known, residence address of each nominee proposed in such notice, (ii)
the principal occupation or employment of each such nominee and (iii) the number
of shares of stock of the Corporation which are beneficially owned by each such
nominee.

            The Chairman of the meeting may, if the facts warrant, determine and
declare to the meeting that a nomination was not made in accordance with the
foregoing procedure, and, if he should so determine, he shall so declare to the
meeting and the defective nomination shall be disregarded.

      EIGHTH:   (a)1. In addition to any affirmative vote required by law, and
except as otherwise expressly provided in sections (b) and (c) of this Article
EIGHTH:

            (A) any merger or consolidation of the Corporation or any Subsidiary
(as hereinafter defined) with or into (i) any Interested Stockholder (as
hereinafter defined) or (ii) any other corporation (whether or not itself an
Interested Stockholder) which, after such merger or consolidation, would be an
Affiliate (as hereinafter defined) of an Interested Stockholder; or

            (B) any sale, lease, exchange, mortgage, pledge, transfer or other
disposition (in one transaction or a series of related transactions) to or with
an Interested Stockholder, or an Affiliate of any Interested Stockholder, of any
assets of the Corporation or any Subsidiary having an aggregate fair market
value of $5,000,000 or more; or

            (C) the issuance or transfer by the Corporation or any Subsidiary
(in one transaction or a series of related transactions) of any securities of
the Corporation to 


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any Interested Stockholder, or any Affiliate of any Interested Stockholder, in
exchange of cash, securities or other property (or a combination thereof) having
an aggregate fair market value of $5,000,000 or more; or

            (D) the adoption of any plan or proposal for the liquidation or
dissolution of the Corporation; or

            (E) any reclassification of securities (including any reverse stock
split), or recapitalization of the Corporation, or any merger or consolidation
of the Corporation with any of its Subsidiaries or any similar transaction
(whether or not with or into or otherwise involving an Interested Stockholder)
which has the effect, directly or indirectly, of increasing the proportionate
share of the outstanding shares of any class of equity or convertible securities
of the Corporation or any Subsidiary which is directly or indirectly owned by
any Interested Stockholder, or any Affiliate of any Interested Stockholder;
shall require the affirmative vote of the holders of at least 75% of the
outstanding shares of capital stock of the Corporation entitled to vote
generally in the election of directors, considered for the purpose of this
Article EIGHTH as one class ("Voting Shares"). Such affirmative vote shall be
required notwithstanding the fact that no vote may be required, or that some
lesser percentage may be specified, by law or in any agreement with any national
securities exchange or otherwise.

      2.    The term "business combination" as used in this Article EIGHTH shall
mean any transaction which is referred to in any one or more of clauses (A)
through (E) or paragraph 1 of this section (a).

      (b)   The provisions of section (a) of this Article EIGHTH shall not be
applicable to any particular business combination and such business combination
shall require only such affirmative vote as is required by law and any other
provisions of the Certificate of Incorporation or by-laws if such business
combination has been approved by a majority of the whole Board.

      (c)   For the purposes of this Article EIGHTH:

      1.    A "person" shall mean any individual, firm, corporation or other
entity.

      2.    "Interested Stockholder" shall mean, in respect of any business
combination, any person (other than the Corporation or any Subsidiary) who or
which , as of the record date for the determination of stockholders entitled to
notice of and to vote on such business combination, or immediately prior to the
consummation of any such transaction:

      (A)   is the beneficial owner, directly or indirectly, of more that 30% of
the Voting Shares; or

      (B)   is an Affiliate of the Corporation and at any time within two years
prior thereto was the beneficial owner, directly or indirectly, of not less than
20% of the then outstanding Voting Shares; or


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      (C)   is an assignee of or has otherwise succeeded to any shares of
capital stock of the Corporation which were at any time within two years prior
thereto beneficially owned by any Interested Stockholder, and such assignment or
succession shall have occurred in the course of a transaction or series of
transactions not involving a public offering within the meaning of the
Securities Act of 1933.

Provided, however, that no person who on the date of the adoption of this
Article EIGHTH would otherwise by a "Interested Stockholder" as defined in this
subsection 2 shall be deemed to be an "Interested Stockholder".

      3.    A person shall be "beneficial owner" of any Voting Shares:

      (A)   which such person or any of its Affiliates and Associates (as
hereinafter defined) beneficially own, directly or indirectly, or

      (B)   which such person or any of its Affiliates or Associates has (i) the
right to acquire (whether such right is exercisable immediately or only after
the passage of time), pursuant to any agreement, arrangement or understanding or
upon the exercise of conversion rights, exchange rights, warrants or options, or
otherwise, or (ii) the right to vote pursuant to any agreement, arrangement or
understanding, or

      (C)   which are beneficially owned, directly or indirectly, by any other
person with which such first mentioned person or any of its Affiliates of
Associates has any agreement, arrangement or understanding for the purpose of
acquiring, holding, voting or disposing of any shares of capital stock of the
Corporation.

      4.    The outstanding Voting Shares shall include shares deemed owned
through application of paragraph 3 above but shall not include any other Voting
Shares which may be issuable pursuant to any agreement, or upon exercise of
conversion rights, warrants or options or otherwise.

      5.    "Affiliate" and "Associate" shall have the respective meanings given
those terms in Rule 12b-2 of the General Rules and Regulations under the
Securities Exchange Act of 1934 as in effect on the date of the adoption of this
provision.

      6.    "Subsidiary" shall mean any corporation of which a majority of any
class of equity security (as defined in Rule 3all-1 of the General Rules and
Regulations under the Securities Exchange Act of 1934 as in effect on the date
of the adoption of this provision), is owned, directly or indirectly, by the
Corporation; provided, however, that for the purposes of the definition of
Interested Stockholder set forth in paragraph 2 of this section (c), the term
"Subsidiary" shall mean only a corporation of which a majority of each class of
equity security is owned, directly or indirectly, by the Corporation.

      (d)   A majority of the directors shall have the power and duty to
determine for the purposes of this Article EIGHTH on the basis of information
known to them, (1) the number of Voting Shares beneficially owned by any person,
(2) whether a person is an 


<PAGE>   8

Affiliate or Associate of another, (3) whether a person has an agreement,
arrangement or understanding with another as to the matters referred to in
paragraph 3 of section (c), or (4) whether the assets subject to any business
combination or the consideration received for the issuance or transfer of
securities by the Corporation or any Subsidiary has an aggregate fair market
value of $5,000,000 or more.

      (e)   Nothing contained in this Article EIGHTH shall be construed to
relieve any Interested Stockholder from any fiduciary obligation imposed by law.

      NINTH: Notwithstanding anything contained in this Certificate of
Incorporation to the contrary, the affirmative vote of the holders of at least
75% of the shares of the Corporation then entitled to be voted in an election of
directors shall be required to amend or repeal, or to adopt any provision
inconsistent with Articles FIFTH, SIXTH, SEVENTH, EIGHTH or NINTH of this
Certificate of Incorporation, except that only the affirmative vote of the
holders of a simple majority of the shares of the Corporation then entitled to
be voted in an election of directors shall be required to amend or repeal, or to
adopt any provision inconsistent with Articles FIFTH, SIXTH, or SEVENTH of this
Certificate of Incorporation if such amendment, repeal or adoption shall have
been approved by a majority of the members of the Board of Directors.

      TENTH: No director of the Corporation shall be personally liable to the
Corporation or its shareholders for monetary damages for breach of fiduciary
duty as a director; provided, however that the foregoing clause shall not apply
to any liability of a director (i) for any breach of the director's duty of
loyalty to the Corporation or its shareholders, (ii) for acts or omissions not
in good faith or which involve intentional misconduct or a knowing violation of
law, (iii) under Section 174 of the General Corporation Law of the State of
Delaware, or (iv) for any transaction from which the director derived an
improper personal benefit. This Article TENTH shall not eliminate or limit the
liability of a director for any act or omission occurring prior to the time this
Article TENTH became effective."

      IN WITNESS WHEREOF, this Restated Certificate of Incorporation has been
executed on this 13th day of May, 1997.

                                 Rollins Environmental Services, Inc.


                                 BY: /s/  John W.  Rollins, Jr.
                                   --------------------------------------
                                 Senior Vice Chairman of the Board