W. Va. Code § 17E-1-15

(a) A person who drives a commercial motor vehicle within this state is deemed to have given consent, subject to provisions of section four, article five, chapter seventeen-c of this code, to take a test or tests of that person's blood, breath or urine for the purpose of determining that person's alcohol concentration, or the presence of other drugs.

(b) A test or tests may be administered at the direction of a law-enforcement officer, who after lawfully stopping or detaining the commercial motor vehicle driver, has reasonable cause to believe that driver was driving a commercial motor vehicle while having alcohol in his or her system.

(c) A person requested to submit to a test as provided in subsection (a) of this section must be warned by the law-enforcement officer requesting the test that a refusal to submit to the test will result in that person being disqualified from operating a commercial motor vehicle under section thirteen or fifteen of this article.

(d) If the person refuses testing, or submits to a test which discloses an alcohol concentration of four hundredths of one percent or more, by weight, that law-enforcement officer shall submit a sworn report to the Division of Motor Vehicles certifying that the test was requested pursuant to subsection (a) of this section and that the person refused to submit to testing, or submitted to a test which disclosed an alcohol concentration of four hundredths of one percent or more, by weight.

(e) Upon receipt of the sworn report of a law-enforcement officer submitted under subsection (d) of this section, the Commissioner shall enter an order revoking the person's driver's license in accordance with section seven, article five, chapter seventeen-c of this code and disqualifying the person from driving a commercial motor vehicle for the period of time prescribed in section thirteen of this article.