In determining standard practice, the commission will be guided by the provisions of the American Water Works Association, and such other codes and standards that are generally accepted by the industry, except as modified by this commission, or municipal regulations within their jurisdiction. Each system shall construct, install, operate, and maintain its plant, structures, equipment, and lines in accordance with these standards, and in such manner to best accommodate the public, and to prevent interference with service furnished by other retail public utilities insofar as practical.
30 Tex. Admin. Code § 291.95