(1) Under RCW 18.43.130(6) the provisions of the act shall not be construed to prevent or affect the practice of officers or employees of the government of the United States while engaged within the state in the practice of the profession of engineering or land surveying for the government of the United States; provided:

(a) That all work performed is for the exclusive use of the federal government; and

(b) That all work performed is wholly contained within the confines of lands held by the federal government (federal enclave).

(2) Any engineering work that is performed and/or constructed for the benefit of a private citizen or business entity, even if directly adjoining lands held by the federal government, must be performed by or under the direct supervision of an engineer licensed in accordance with the requirements of chapter 18.43 RCW.

(3) Any surveying work that is performed for boundaries between lands held by the federal government and lands held by a private citizen or business entity, must be performed by or under the direct supervision of a land surveyor licensed in accordance with the requirements of chapter 18.43 RCW or under the authority of the Secretary of the Interior through special instructions approved by the Bureau of Land Management.