There is an Indoor Plumbing Program. The Department shall: operate the Indoor Plumbing Program; and make loans for rehabilitation projects that provide for adequate indoor plumbing from the Special Loan Programs Fund under this subtitle. The terms for indoor plumbing loans shall meet the requirements of §§ 4-917 through 4-919 of this subtitle. The Department may forgive all or part of a deferred payment loan, if: the loan is made to a family of limited income that owns and occupies the dwelling and whose income is within a lower income range established under § 4-916(b) of this subtitle; and the Secretary determines that the family of limited income does not have enough income to repay the principal amount of the loan. To qualify for an indoor plumbing loan, an applicant shall: own a building that is otherwise structurally sound, or for which the applicant provides a commitment from a lender to finance improvements needed to make the building structurally sound, and that: has no or incomplete indoor plumbing or a failing septic system; and needs indoor plumbing pipes, equipment, wells, septic tanks or other on-site sewer system, or a connection to a community water or sewer system; live in the building and be a family of limited income, or rent at least two-thirds of the dwellings in the building to families of limited income; and submit to the Department a proposal for installing an adequate indoor plumbing system for water supply and sewage disposal, including any needed septic system, well, or connection to a community sewer or water system that meets the requirements of the Department of the Environment and every other governmental unit that has jurisdiction over the system.