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                                EXHIBIT 10.12B

                              FIRST AMENDMENT OF
                   SWWC RIGHT OF FIRST REFUSAL AGREEMENT AND
                         SWWC CALL PURCHASE AGREEMENT
                                        

     This First Amendment of SWWC Right of First Refusal Agreement and SWWC Call
Purchase Agreement is made and entered into by RTNT, Inc., a Texas Corporation
("RTNT') and Southwest Water Company, Inc., a Delaware Corporation ("SWWC") to
be effective the 22nd day of May 1998.

                                    RECITALS
                                        
     WHEREAS, SWWC and RTNT have previously entered into an SWWC Right of
First Refusal Agreement and SWWC Call Purchase Agreement ("SWWC Call Agreement")
which was executed as of May 23, 1996; and

     WHEREAS this SWWC Call Agreement placed certain restrictions on stock in
Windermere Utility Co., Inc. ("WUC") held by RTNT; and

     WHEREAS this SWWC Call Agreement gave SWWC certain rights to the WUC stock
held by RTNT; and

     WHEREAS the SWWC Call Agreement had certain time periods in which the
rights of RTNT were operative; and

     WHEREAS SWWC and RTNT also entered into a "RTNT Right of First Refusal and
RTNT Call Purchase Agreement" ("SWWC Call Agreement"); and

     WHEREAS the parties hereto being the parties to the SWWC Call Agreement and
the RTNT Call Agreement, for various reasons wish to extend all the time periods
for the exercise of the various rights of SWWC under the SWWC Call Agreement;
and

     NOW, THEREFORE, for and in consideration of the premises and the mutual
covenants and ten dollars ($10.00) and other good and valuable consideration
hereinafter set forth and for other good and valuable consideration including
but not limited to the promises of the parties, the parties hereby agree as
follows:

1.   The first sentence of Paragraph 1 of the SWWC RTNT Call Agreement which is
entitled "Restriction on RTNT Stock" shall be amended to read as follows:

     "RTNT shall not sell, transfer, assign, or otherwise dispose of the RTNT
     WUC stock or any portion thereof to any person or entity for period ending
     two hundred ten (210) days after the third anniversary of the date hereof."

2.   The provisions of Paragraph 2 of the SWWC Call Agreement which is entitled
"Call by SWWC," specifically, the first sentence of Paragraph 2 of the SWWC Call
Agreement shall be amended to read as follows:

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     SWWC shall have, for a period beginning on the day after December 31, 1998
     and ending two hundred ten (210) days after the third anniversary date of
     this SWWC Call Agreement, the right to require RTNT to sell all of the RTNT
     WUC stock it owns in WUC at that time."

3.   Paragraph 3 of the SWWC Call Agreement which is entitled "Offer to RTNT"
shall be amended by amending the first sentence to read as follows:

     "RTNT shall, after such two hundred ten (210) days following the third
     anniversary hereof, not sell, transfer, assign, or otherwise dispose of the
     RTNT WUC Stock or any portion thereof to any person and/or entity except as
     provided herein."

4.   The first sentence of Paragraph 4 of the SWWC Call Agreement entitled "RTNT
Call Agreement: shall be amended as follows:

     "The provisions of Paragraphs 1, 2, and 3 above have no further effect if
     prior to December 31, 1998 exercises its right to call upon SWWC to sell
     all of its stock in WUC pursuant to the RTNT Right of First Refusal
     Agreement and RTNT Call Purchase Agreement of even date herewith and closes
     and funds said purchase."

5.   The SWWC Call Agreement, the RTNT Call Agreement, the First Amendment to
SWWC Right of First Refusal Agreement and SWWC Call Purchase Agreement, and the
Equity Agreement and the documents referred to therein, (a) constitute the
entire agreement among the parties and supercede all prior agreements and
understanding, both written and oral, among the parties with respect to the
subject matter hereof, (b) may be executed in several counterparts, each of
which shall constitute one and the same instrument, (c) except as expressly set
forth herein, shall inure to the benefit of, and be binding upon, the
successors, assigns. legal representatives, administrators, and heirs of each
party and are not intended to confer upon any person other than the parties and
their successors assigns, legal representatives, administrators, and heirs any
rights or remedies hereunder, and (d) shall be governed in all respects.
including validity, interpretation, and effect by the laws of the state of
Texas.  The captions in this First Amendment to SWWC Right of First Refusal
Agreement and SWWC Call Purchase Agreement are for convenience of reference only
and shall not affect its interpretation in any respect.

6.   Any notice consent or communication required or permitted to be given under
this First Amendment to SWWC Right of First Refusal Agreement and SWWC Call
Purchase Agreement must be in writing and delivered to a person or by confirmed
facsimile or by registered mail, return receipt requested, postage prepaid
addressee restricted as follows:

          To: RTNT, Inc.,
          P.O. Box 161173
          Austin Texas 78716
          (tel.) 512-327-0869
          (fax) 512-327-0869

          To: Southwest Water Company
          225 North Barranca Avenue Suite 200
          West Covina California 91791-1605
          (tel.) 626-915 1551
          (fax) 626-915-1558

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     ANY SUCH NOTICE CONSENT OR OTHER COMMUNICATION SHALL BE DEEMED GIVEN WHEN
DELIVERED IN PERSON OR SENT BY CONFIRMED FACSIMILE OR IF MAILED, FIVE (5) DAYS
AFTER MAILING.

6.   Any provision of this First Amendment to SWWC Right of First Refusal
Agreement and SWWC Call Purchase Agreement which is prohibited or unenforceable
in any jurisdiction as to such jurisdiction be ineffective to the extent of such
prohibition or unenforceability without invalidating the remaining provisions of
this First Amendment to SWWC Right of First Refusal Agreement and SWWC Call
Purchase Agreement and any such prohibition or unenforceability in any
jurisdiction shall not invalidate or render unenforceable such provision in any
other jurisdiction.

7.   This First Amendment to SWWC Right of First Refusal Agreement and SWWC
Call Purchase Agreement shall be subject to the RTNT and SWWC Arbitration
Agreement dated to be effective the 23rd of May 1996.

8.   This First Amendment to SWWC Right of First Refusal Agreement and SWWC
Call Purchase Agreement shall be binding upon and inure to the benefit of SWWC
and RTNT and their respective successors, representatives and assigns.

9.   For purposes hereof, a facsimile copy of this First Amendment of SWWC
Right of First Refusal and SWWC Call Purchase Agreement including the signature
pages hereto, shall be deemed to be an original. Notwithstanding the forgoing,
the parties shall deliver original execution copies of this First Amendment of
SWWC Right of First Refusal and SWWC Call Purchase Agreement to one another
immediately after execution.

Executed as of the 22nd day of May 1998.


                              RTNT, INC., a Texas Corporation


                              By: /s/ Thom W. Farrell        
                                  -------------------        
                                  THOM W. FARRELL, PRESIDENT 
                                                            
                                                            
                              SOUTHWEST WATER COMPANY       
                                                            
                                                            
                              By: /s/ Anton C. Garnier      
                                  --------------------
                                  ANTON C. GARNIER, PRESIDENT 



ATTEST:

/s/ Peter J. Moerbeek
---------------------
PETER MOERBEEK, VICE PRESIDENT
AND SECRETARY

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