Exhibit 32.1 CERTIFICATION PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002 (SUBSECTIONS (a) AND (b) OF SECTION 1350, CHAPTER 63 OF TITLE 18, UNITED STATES CODE) Pursuant to section 906 of the Sarbanes-Oxley Act of 2002 (subsections (a) and (b) of section 1350, chapter 63 of Title 18, United States Code), the undersigned officers of Alternative Technology Resources, Inc. (the "Company"), does hereby certify with respect to the Annual Report of the Company on Form 10-K for the year ended June 30, 2003 as filed with the Securities and Exchange Commission (the "Form 10-K") that, to the best of their knowledge: (1) the Form 10-K fully complies with the requirements of section 13(a) or 15(d) of the Securities Exchange Act of 1934; and (2) the information contained in the Form 10-K fairly presents, in all material respects, the financial condition and results of operations of the Company. Date: October 2, 2003 /s/ Mark W. Rieger --------------- --------------------------------- Mark W. Rieger Chief Executive Officer and Chief Financial Officer (Principal Executive Officer and Financial Officer)