The following words and terms, unless the context clearly indicates a different meaning, have the following meanings:

(1) “Affected residence”  refers to a residence which has an ISDS failure or a contaminated domestic water supply;

(2) “Contaminated domestic water supply”  refers to the primary source of drinking and household water for a residence which fails to meet generally accepted drinking water standards, or which the department of health has certified as undrinkable;

(3) “Domestic individual sewage disposal system”  (“ISDS”) refers to an existing disposal system which services an owner occupied, single family residence;

(4) “Failed domestic individual disposal system”  refers to an ISDS system which has been determined to have failed by the land resources section of the department of environmental management, or a system which has required pumping out more than four (4) times in a one-year period;

(5) “Multiple domestic individual sewage disposal system failure”  refers to a number of failed ISDS systems in close proximity to one another.