Md. Code, Tax - Property § 8–237

A septic system or a well that functions in a deficient manner shall be assessed to the owner of the real property on which it is located on the basis of the deficiency, if:

(1) the owner of the real property:

(i) notifies the supervisor; and

(ii) states that the condition affects the value of the real property; and

(2) the supervisor considers that the deficiency affects the value of the real property.