Patent ID: 6841781

Claim:
A method comprising the steps of: a) generating with a generator electromagnetic radiation including at least one predetermined exposure wavelength that is both significantly absorbed by water and is not significantly absorbed by material composing a structure, and at least one predetermined reference wavelength that is neither significantly absorbed by water nor the material composing the structure; b) exposing with the generator a predetermined area of the structure with the generated electromagnetic radiation; c) sensing with a sensor unit at least a portion of the generated radiation from the exposed area of the structure to determine a first intensity level of the radiation at the predetermined exposure wavelength, and a second intensity level at the predetermined reference wavelength; d) comparing the first and second intensity levels; and e) determining that the predetermined area includes water if the first and second levels differ by at least a predetermined amount, and a. testing to confirm that the predetermined area includes water, and if water is confirmed, determining the source of the water detected by i. exposing a water-confirmed area to second electromagnetic radiation including at least one exposure wavelength that is significantly absorbed by at least one water-soluble substance and that is not significantly absorbed by material composing the structure, and at least one reference wavelength not significantly absorbed by either the water-soluble substance or the material composing the structure; ii. sensing the second electromagnetic radiation from the water-confirmed area at the exposure wavelength to determine a third intensity level, and at the reference wavelength to determine a fourth intensity level; iii. comparing the third and fourth intensity levels; iv. determining the source of water to be ground water if the third and forth intensity levels differ by at least a second predetermined amount; or f) determining that the predetermined area includes no water if the first and second levels do not differ by at least the undetermined amount or if water is not confirmed by testing.