Exhibit 32


                                  CERTIFICATION
                       PURSUANT TO 18 U.S.C. SECTION 1350,
                       AS ADOPTED PURSUANT TO SECTION 906
                        OF THE SARBANES-OXLEY ACT OF 2002

Pursuant  to  Section  906  of  the  Sarbanes-Oxley  Act of  2002,  each  of the
undersigned  certifies  that this Annual  Report on Form 10-K for the year ended
December 31, 2005,  fully  complies  with the  requirements  of Section 13(a) or
15(d),  as  applicable,  of the  Securities  Exchange  Act of 1934  and that the
information  contained in this Report fairly presents, in all material respects,
the financial  condition  and results of operations of California  Water Service
Group.




   Date: March 9, 2006                        /s/ Peter C. Nelson
                                              ------------------------------
                                              PETER C. NELSON
                                              Chief Executive Officer
                                              California Water Service Group



   Date: March 9, 2006                        /s/ John S. Tootle
                                              ------------------------------
                                              JOHN S. TOOTLE
                                              Acting Chief Financial Officer
                                              California Water Service Group