Exhibit 4.3


                            SECOND AMENDMENT TO THE
                               RIGHTS AGREEMENT

         THIS SECOND AMENDMENT TO THE RIGHTS AGREEMENT (this "Amendment"),
dated as of September 16, 2001, is made by and between American Water Works
Company, Inc., a Delaware corporation (the "Company"), and Fleet National Bank
(formerly known as BankBoston N.A.), a national banking association, as Rights
Agent (the "Rights Agent"). The Company and the Rights Agent may be
individually referred to herein as a "Party" and, collectively, as the
"Parties".

                                  Background

          A. The Parties entered into a Rights Agreement, dated as of February
18, 1999, as amended by the First Amendment to the Rights Agreement, dated as
of June 1, 2000 (the "Agreement"). Capitalized terms not otherwise defined
herein shall have the meaning ascribed to such terms in the Agreement.

          B. The Company, RWE Aktiengesellschaft, a company organized under
the laws of the Federal Republic of Germany ("Guarantor"), Thames Water Aqua
Holdings GmbH, a company organized under the laws of the Federal Republic of
Germany and a wholly owned subsidiary of Guarantor ("Parent"), and Apollo
Acquisition Company, a Delaware corporation and a wholly owned subsidiary of
Parent ("Sub"), are entering into an Agreement and Plan of Merger, dated as of
the date hereof (as amended or supplemented from time to time, the "Merger
Agreement"), pursuant to which Sub shall be merged with and into the Company
with the Company surviving the merger.

          C. Parent and certain stockholders of the Company, in connection
with the Merger Agreement are entering into that certain Voting Agreement,
dated as of the date hereof (as amended or supplemented from time to time, the
"Voting Agreement").

          D. The Board of Directors of the Company has determined that an
amendment to the Rights Agreement as set forth herein is advisable and in the
best interests of the Company and its stockholders.

          E. Pursuant to Section 27 of the Agreement, the Company has directed
the Rights Agent to join this Amendment.

                                     Terms

         In consideration of the mutual covenants contained herein and in the
Agreement and intending to be legally bound hereby, the Parties agree as
follow:

          1. Amendment of Section 1(a). The definition of "Acquiring Person"
in Section 1(a) of the Agreement is hereby amended by adding the following at
the end thereof:


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               "(D) none of RWE Aktiengesellschaft, a company organized under
          the laws of the Federal Republic of Germany ("Guarantor"), Thames
          Water Aqua Holdings GmbH, a company organized under the laws of the
          Federal Republic of Germany and a wholly owned subsidiary of
          Guarantor and Apollo Acquisition Company, a Delaware corporation,
          and a wholly owned subsidiary of Parent ("Sub" and collectively with
          Guarantor and Parent, "Acquiror") nor any of their respective
          Affiliates or Associates shall be deemed to be an Acquiring Person
          solely by reason of the approval, execution, delivery and
          performance of the Agreement and Plan of Merger, dated as of
          September 16, 2001, by and among the Company, Guarantor, Parent and
          Sub (as amended or supplemented from time to time, the "Merger
          Agreement"), or the Voting Agreement, dated as of September 16, 2001
          by and among Parent and certain stockholders of the Company party
          thereto as of such date and the Willard M. Ware Q-Tip Trust and the
          Willard M. Ware Residual Trust at such time as they may become
          parties thereto (the "Voting Agreement") or the consummation of any
          other transaction to be effected thereby (including any acquisition
          of Company Common Stock contemplated by Section 4.03(b) of the
          Merger Agreement)."

          2. Amendment to Section 1(p). The definition of "Shares Acquisition
Date" in Section 1(p) of the Agreement is amended by inserting the following
sentence at the end thereof:

          "Notwithstanding anything in this Agreement to the contrary, a
          Shares Acquisition Date shall not be deemed to have occurred solely
          as the result of the public announcement, approval, execution,
          delivery and performance of the Merger Agreement or the Voting
          Agreement or the consummation of any other transaction to be
          effected thereby (including any acquisition of Company Common Stock
          contemplated by Section 4.03(b) of the Merger Agreement)."

          3. Amendment to Section 1(r). The definition of "Triggering Event"
in Section 1(r) of the Agreement is hereby deleted in its entirety and
replaced with the following:

               "(r) "Triggering Event" shall mean any Section 11(a)(ii) Event
          or Section 13 Event, provided that none of the approval, execution,
          delivery and performance of the Merger Agreement or the Voting
          Agreement or the consummation of any other transaction to be
          effected thereby (including any acquisition of Company Common Stock
          contemplated by Section 4.03(b) of the Merger Agreement) shall be
          deemed to be a Triggering Event."

          4. Amendment to Section 3(a). Section 3(a) of the Agreement is
hereby amended by inserting the following sentence immediately after the last
sentence thereof:

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<PAGE>

          "Notwithstanding anything in this Agreement to the contrary, a
          Distribution Date shall not be deemed to have occurred solely by
          reason of the approval, execution, delivery and performance of the
          Merger Agreement or the Voting Agreement or the consummation of any
          other transaction to be effected thereby (including any acquisition
          of Company Common Stock contemplated by Section 4.03(b) of the
          Merger Agreement)."

          5. Amendment to Section 11(a)(ii). Section 11(a)(ii) of the
Agreement is hereby amended by adding the following sentence at the end
thereof:

          "Notwithstanding anything in this Agreement to the contrary, none of
          the approval, execution, delivery and performance of the Merger
          Agreement or the Voting Agreement or the consummation of any other
          transaction to be effected thereby (including any acquisition of
          Company Common Stock contemplated by Section 4.03(b) of the Merger
          Agreement) shall cause the Rights to be adjusted or become
          exercisable in accordance with this Section 11(a)(ii)."

          6. Amendment to Section 13. The following Section 13(d) is hereby
added after Section (c):

               "(d) Notwithstanding anything contained in this Agreement to
               the contrary, in no event shall the provisions of this Section
               13 apply to the approval, execution, delivery and performance
               of the Merger Agreement or the Voting Agreement or the
               consummation of any other transaction to be effected thereby
               (including any acquisition of Company Common Stock contemplated
               by Section 4.03(b) of the Merger Agreement)."

          7. Additional Amendment. The following Section 35 is hereby added
after Section 34:

               "Section 35. Notwithstanding anything contained in this
               Agreement to the contrary, this Agreement and the Rights shall
               terminate and be of no further force and effect immediately
               prior to the Effective Time (as defined in the Merger
               Agreement)."

          8. Other Provisions Unaffected. This Amendment shall be deemed to be
in full force and effect immediately prior to the execution and delivery
of the Merger Agreement and the Voting Agreement. Except as expressly
modified herein, all arrangements, agreements, terms, conditions and
provisions of the Agreement remain in full force and effect, and this
Amendment and the Agreement, as hereby modified, shall constitute one and
the same instrument.

          9. Miscellaneous.
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<PAGE>

          a. Counterparts. This Amendment may be executed in any number of
counterparts and each of such counterparts shall for all purposes be deemed to
be an original, and all such counterparts shall together constitute but one
and the same instrument.

          b. Governing Law. This Amendment, the Agreement, each Right and each
Right Certificate issued hereunder or thereunder shall be deemed to be a
contract made under the laws of the State of Delaware and for all purposes
shall be governed by and construed and in accordance with the laws of such
State applicable to contracts to be made and performed entirely within such
State.

          c. Further Assurances. Each Party shall cooperate and take such
action as may be reasonably requested by another Party in order to carry out
the provisions and purposes of this Amendment, the Agreement, generally, and
the transactions contemplated hereunder and/or thereunder.

          d. Descriptive Headings. Descriptive headings of the several
Sections of this Amendment and the Agreement are inserted for convenience only
and shall not control or affect the meaning or construction of any of the
provisions hereof or thereof.

          e. Entire Agreement. This Amendment and the Agreement, and all of
the provisions hereof and /or thereof, shall be binding upon and inure to the
benefit of the Parties and their respective successors and permitted assigns
and executors, administrators and heirs. This Amendment, together with the
Agreement, sets forth the entire agreement and understanding among the Parties
as to the subject matter hereof and merges with and supercedes all prior
discussions and understandings of any and every nature among them.


          IN WITNESS WHEREOF, the Parties have executed this Second Amendment
to the Rights Agreement as the date first set forth above.



Attest:                                   AMERICAN WATER WORKS COMPANY, INC.

By:    /s/ W. Timothy Pohl                By:   /s/ J. James Barr
       ------------------------------        --------------------------------
       Name:  W. Timothy Pohl                Name:  J. James Barr
       Title:  General Counsel               Title:  President and Chief
                and Secretary                            Executive Officer

Attest:                                   FLEET NATIONAL BANK

By:    /s/ Erika Illingworth              By:   /s/ Joshua P. McGinn
       -------------------------------       --------------------------------
       Name:  Erika Illingworth              Name:  Joshua P. McGinn
       Title:  Account Manager               Title:  Senior Account Manager


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