EXHIBIT 15
October 22, 1996

Public Service Company of Colorado

We are aware  that  Public  Service  Company of  Colorado  has  incorporated  by
reference in this  registration  statement,  pertaining to the  registration  of
$400,000,000 of First  Collateral  Trust Bonds, in one or more series of secured
medium-term  notes,  its Form 10-Q's for the  quarters  ended March 31, 1996 and
June 30, 1996,  which include our reports dated May 10, 1996 and August 6, 1996,
respectively, covering the unaudited consolidated condensed financial statements
contained therein. Pursuant to Regulation C of the Securities Act of 1933, these
reports are not  considered  a part of the  registration  statement  prepared or
certified  by our Firm or a report  prepared or certified by our Firm within the
meaning of Sections 7 and 11 of the Act.


                                ARTHUR ANDERSEN LLP