It's not as simple as pot-oblivion fans might think. The university probably has to do drug testing to achieve this below, and lower insurance rates……..
The Drug-Free Workplace Act of 1988:
The Drug-Free Workplace Act of 1988 (41 U.S.C. 81) is an act of the United States which
requires some Federal contractors and all Federal grantees to agree that they will provide drug-free workplaces as a precondition of receiving a contract or grant from a Federal agency.
Although all covered contractors and grantees must maintain a drug-free workplace, the specific components necessary to meet the requirements of the Act vary based on whether the contractor or grantee is an individual or an organization.
The requirements for organizations are more extensive, because organizations have to take comprehensive, programmatic steps to achieve a workplace free of drugs. (wikipedia)
Princeton University Human Resources -
"Use of Illegal Drugs
The University prohibits the unlawful manufacture, dispensation, possession, use, or distribution of a controlled substance of any kind in any amount on University property, or while in the conduct of University business away from the campus. Penalties for these acts will be administered by the appropriate senior officer, and in accordance with rules and procedures administered by them (for the faculty and other academic staffs, the Dean of the Faculty; for administrators and staff, the Vice President for Human Resources). Penalties range from warning to permanent separation from the University depending on the seriousness of the infraction and the degree to which violation of the policy adversely affects the well-being of the community or the fulfillment of the University's educational mission.
Violations of local ordinances or of state or federal laws regarding controlled dangerous substances by members of the University community may entail University disciplinary actions regardless of where such violations occur, if they are of a serious nature. The manufacture, sale or distribution of illegal drugs, any involvement in illegal drug use or traffic with minors and possession or use of the more dangerous or highly addictive drugs are all considered serious offenses and will be handled accordingly. Depending on the particular circumstances, continued association with the University by violators of this policy may be made contingent upon satisfactory participation in a drug abuse assistance or rehabilitation program.
This policy applies to all members of the University community: faculty, staff, and students. More information about the University's drug policy may be obtained at the Office of the Provost, and by consulting Rights, Rules and Responsibilities, or the appropriate staff policy manual.
It is also University policy, in accordance with the Drug Free Workplace Act of 1988, that all employees, as a condition of employment on projects supported out of federal funds, abide by this University policy regarding controlled dangerous substances and notify the University within five (5) days of any criminal drug statute conviction for a violation occurring at the workplace.
All members of the University community should be aware that New Jersey state law prohibits the illegal possession, use, sale, or manufacture of controlled substances and that violators may be subject to mandatory penalties.
Federal law also provides for loss of certain federal benefits (including student loans and research grants) for conviction under any criminal drug statute. More information about New Jersey and federal drug laws may be obtained at the Office of Public Safety, or the Office of General Counsel.
5.1.2 The Drug Free Workplace Act*-*Office of Human Resources - 5.1.2 The Drug Free Workplace Act