(a) An eligible applicant may apply for a grant to build privately owned treatment works serving one or more principal residences or small commercial establishments.
(b) In addition to those applicable limitations set forth in §§ 35.2100 through 35.2127 the grant applicant shall:
(1) Demonstrate that the total cost and environmental impact of building the individual system will be less than the cost of a conventional system;
(2) Certify that the principal residence or small commercial establishment was constructed before December 27, 1977, and inhabited or in use on or before that date;
(3) Apply on behalf of a number of individual units to be served in the facilities planning area;
(4) Certify that public ownership of such works is not feasible and list the reasons; and
(5) Certify that such treatment works will be properly operated and maintained and will comply with all other requirements of section 204 of the Act.