Full opinion text
OPINION ROSEN, District Judge. I. INTRODUCTION This appeal raises challenging and far-reaching constitutional questions concerning drug testing of teachers and other personnel in our nation’s schools. Not only are a number of the issues presented here of first-impression for our Circuit, but these issues call upon us to consider and reconcile important constitutional and societal values concerning the environment in which our children are educated. Because the law in this area is unsettled and the issues of significant import to our schools and communities, the Court examines these important questions in some detail and at some length. II. BACKGROUND & PROCEDURAL HISTORY Plaintiff Knox County Education Association (“KCEA”), which represents professional employees in the Knox County School System, initiated this action to challenge drug and alcohol testing procedures adopted by Defendant Knox County Board of Education (“Board”), which is the body responsible for the administration, management, and control of the Knox County School System. In the District Court, KCEA made a facial attack on the Board’s “Drug-Free Workplace Substance Abuse Policy,” seeking declaratory and injunctive relief. The policy establishes, inter alia, two different levels of testing: (1) suspicionless drug testing for all individuals who apply for, transfer to, or are promoted to, “safety sensitive” positions within the Knox County School system, including teaching positions; and (2) “reasonable suspicion” drug and/or alcohol testing of all school employees. KCEA challenged both testing programs as violative of the Fourth Amendment’s prohibition against unreasonable searches and seizures. In response, the Board twice moved for summary judgment on the basis that certain positions in the Knox County School system had already been ruled to be “safety sensitive” as a matter of law in a previous decision rendered in litigation challenging an earlier version of the Policy. See, Knox County Education Association v. Knox County Board of Education, No. CIV 3-91-72 (E.D.Tenn. April 13, 1994) (“KCEA I”). Defen-' dant argued, as it argues on appeal, that KCEA I was binding in this matter through the application of the doctrines of res judica-ta and collateral estoppel, and that the new Policy, which was carefully drafted to conform with the requirements for constitutional drug testing enunciated in KCEA I, must be found constitutional. United States District Judge James H. Jarvis denied the motions, finding the language in KCEA I regarding safety sensitive positions dictum. The Board moved for summary judgment a third time, and moved that the District Court take judicial notice of the finding in KCEA I. The District Court predictably denied this motion as well. The matter was tried on November 12, 1996. In an Opinion and Order dated March 4, 1997, the District Court found that the Board’s drug testing policy violated the Fourth Amendment to the extent that (1) it permitted any suspicionless drug testing; and (2) in the manner by which it permitted alcohol testing upon reasonable suspicion. The District Court enjoined the Board from further implementation and enforcement of those sections' of the Policy, and found the remainder of the policy facially valid. This matter is now before the Court on the cross-appeals of the parties. Ill FACTS A. Knox County School System The Knox County School system is comprised of eighty-eight schools, fifty-three of which are elementary schools and thirty-five of which are middle or high schools. Fifty-three thousand students attend the Knox County Schools, roughly half of whom are elementary school students and half are middle or high school students. Thirty-two hundred teachers are employed in the Knox County Schools. According to the Director of Personnel Betty Sparks, a typical day’s work for an elementary school teacher revolves around the students in his or her classroom. Elementary school teachers plan for, instruct, and supervise the children in their classroom during the school day. In addition, teachers supervise children coming and going to school, and monitor them in the hallways and cafeteria. Similarly, the duties of a high school teacher revolve around teaching his or her classes. A high school teacher typically spends six hours of each school day either instructing students or preparing to do so. During the remainder of the school day, high school teachers monitor the hallways when students are changing classés,'and may assume other supervisory duties on a volunteer basis. The Knox County Schools are also staffed by a number of non-teaching professionals who are trained to address the physical and psychological health and safety needs of the students, including nurses, social workers, educational diagnosticians, occupational therapists and physical therapists. To respond to violence or other illegal activity that might occur in or around the schools, Knox County has a Department of School Security comprised of a Chief of Security, four law enforcement investigators, and twenty-four armed, uniformed security officers. One security officer is assigned to each high school, and the remainder of the officers respond to reported incidents at any school. According to Chief of Security Stephen Griffin, even in those schools where there is a uniformed officer, the majority of information concerning students’ behavior comes to the attention of security officers through the observations of the principal or teachers. (J.A. 1122). Griffin testified as follows at trial: Q. Mr. Griffin, since you do not have security officers for every school, are teachers and principals at the schools important to school security? And if so, why? A. Most definitely. They are the front-line of security as far as the schools are concerned. Even in schools where there is a uniformed officer, the majority of information generated to our office is initiated through a principal or administrator. (J.A. 937). Furthermore, Director of Personnel Betty Sparks testified that detecting drug use and the possession of a weapon is among teachers’ responsibilities. (J.A. 890). Ms. Sparks testified that as a teacher “it is vitally important for [her] to be on [her] toes every minute with every youngster [she] is working with.” (J.A. 887). The Security Department reports all incidents, whether criminal or not, that implicate the safety and security of students or staff. The incident reports for 1995-96 school year did not report any unlawful or violent conduct in the fifty-three elementary schools. The records reflect thirty-four assaults on students at the thirty-five middle and high schools, and fourteen assaults on teachers or principals (with no incidents occurring at all in twenty schools). There is no evidence that a pronounced drug/alcohol abuse problem exists among the Knox County teachers, nor is there evidence that the inattentiveness or negligence of a teacher has ever contributed to, or was related in any way, to these assaults or to any security incident. With respect to non-violent but unlawful conduct, the Board’s records indicate that during the 1995-96 school year, thirty-five students were charged with the possession of a weapon and seventy-four were charged with the possession or use of alcohol or drugs. Again, there is no record evidence that a teacher has ever failed to report a student for the use or possession of drugs, alcohol, or weapons. B. Prior Litigation Over the 1991 Drug Testing Policy In December of 1989, the Board adopted a “Drug-Free Workplace Policy,” which was then revised several times over the course of the next two and a half years. In 1991, KCEA filed suit challenging the policy on Fourth Amendment grounds. In that ease, the district court, Judge Jordan presiding, noted that the policy did not describe the methods or procedures to be followed in obtaining or testing urine samples, nor did it assure the employee applicants that their privacy interests in the results would be protected. This led the court to conclude: “Because the privacy interests of the professional employee applicants in this case are not protected at all by the policy as it is written', the court finds that for this reason alone the policy must fail constitutional examination.” (J.A. 282). The court did not end its inquiry at that point, however. The court addressed the second part of the balancing test to examine whether the governmental interests were strong enough to test all professional employees, irrespective of the nexus their position had to the safety of the children. The court then found that of the professional employee positions subject to pre-employment drug screening, principals (and assistant principals), teachers (and traveling teachers), teacher aids, and school secretaries occupied safety sensitive positions because “[a]ny lapse in attention or judgment on the part of these employees could result in an immediate threat to a child’s safety.” (J.A. 284-85). This led the court to conclude: Thus, even if the policy adequately protected the privacy interests of the professional employees, and the court finds that it does not, the only professional employees which the court considers subject to pre-employment testing are principals, assistant principals, teachers, traveling teachers, teacher aids, and school secretaries. (J.A. 287). In the instant litigation, a crucial issue is whether teachers are “safety sensitive” employees- — a question which the Board claims has already been resolved by KCEAI. C. 1994 Drug Testing Policy On June 1, 1994, in response to Judge Jordan’s decision, the Board of Education met in regular session and voted to adopt the “Drug-Free Workplace Substance Abuse Policy” for implementation in the Knox County School system. As adopted, the Policy establishes a comprehensive drug and alcohol testing program for the Board of Education’s employees. The Policy notes that the Federal Anti-Drug Act, 41 U.S.C. § 702, requires federal grant recipients, such as the Board, to establish a drug-free workplace. The Policy describes its goals and objectives as follows: 1. To establish, promote, and maintain a safe, healthy, working and learning environment for employees and students. 2. To aid the affected employee in locating a rehabilitation program for employees with self-admitted or detected substance abuse problem. 3. To promote the reputation of the Knox County School System and its employees as responsible citizens of public trust and employment. 4. To eliminate substance abuse problems in the workplace. 5. To aid in the reduction of absenteeism, tardiness, and apathetic job performance. 6. To provide a clear standard of job performance for Knox County Schools employees. 7. To provide a consistent model of substance-free behavior for students. (1994 Policy, J.A. 1006-1007). The Policy divides the tested employees into two distinct groups: (1) those who may be the subject of suspicionless testing (those who may be tested pre-employment for “safety sensitive” positions, pre-transfer for “safety sensitive” positions, and upon return to duty after undergoing rehabilitation); and (2) those who may be tested for reasonable suspicion of drug or alcohol impairment while at work (all employees). The substance abuse policy prohibits any Board of Education employee from being under the influence of an illegal drug or alcohol while on duty, on Knox County Board of Education property, or in attendance at a System-approved or school-related function. 1. Suspicionless Testing The Policy allows suspicionless testing for people applying for positions that are “safety sensitive.” The Policy defines “safety sensitive” positions as those positions “where a single mistake by such employee can create an immediate threat of serious harm to students and fellow employees.” (J.A. 1007). According to the Policy, and consistent with the ruling in KCEA I, this category includes principals, assistant principals, teachers, traveling teachers, teacher aides, substitute teachers, school secretaries and school bus drivers. Applicants for these positions are tested after they are offered a job but before their employment has commenced (i.e., post-offer, pre-employment). They are to be given a copy of the Policy in advance of the physical and are to sign an acknowledgment prior to substance screening, permitting the summary result to be transmitted to the Medical Review Officer (“MRO”) and Director of Personnel. An applicant refusing to complete any part of the drug testing procedure will not be considered a valid candidate for employment with the school system, and such refusal will be considered as a withdrawal of the individual’s application for employment. If substance screening shows a confirmed positive result for which there is no current physician’s prescription, a second confirming test may be requested by the MRO. If the first or any requested second confirming test is positive, any job offer will be revoked. Current employees attempting to transfer into safety sensitive positions — including those who already hold such positions — are also tested. Employees who test positive for illegal drugs on a promotion/transfer test will no longer be considered an applicant for that position. Employees seeking a transfer or promotion who refuse any portion of the drug testing procedure forfeit the opportunity to transfer to, or advance into, a safety sensitive position and are subject to discipline for insubordination (including termination). 2. Reasonable Suspicion Testing Section .05 of the Policy provides for drug and/or alcohol screening based upon reasonable suspicion as follows: Whenever the Knox County Board of Education, through its Director of Personnel or the person authorized to act as the Director in the Director’s absence, and/or the Medical Review Officer, reasonably suspects that an employee’s work performance or on-the-job behavior may have been affected in any way by illegal drugs or alcohol, or that an employee has otherwise violated the Knox County Board of Education Drug-Free Workplace Substance Abuse Policy, the employee may be required to submit a breath and/or urine sample for drug and alcohol testing. When a supervisor observes or is notified of behavior or events that lead the supervisor to believe that the employee is in violation of the Drug-Free Workplace Substance Abuse Policy, the Supervisor should notify the Director of Personnel. An employee who is required to submit to drug/alcohol testing based upon such reasonable suspicion and refuses will be charged with insubordination and [subject to the disciplinary sanctions, including possible termination]. (J.A. 1010). Further, an employee testing positive on a reasonable suspicion test will be found to be in violation of the Policy, and such a violation will constitute grounds for termination. The Policy notes that the School System Director of Personnel, or the person authorized to act in that person’s absence, or the MRO are the only individuals in the Knox County School System authorized to make a determination that reasonable suspicion, or cause, exists to order a drug screen, and are the only individuals in the School System who may order an employee to submit to a drug screen. The Policy describes two types of cases for which the reasonable suspicion procedures may be invoked: (1) Chronic ease Deteriorating job performance or changes in personal traits characteristics where the use of alcohol or drugs may be reasonably suspected as the cause. These cases may develop over a fairly long period of time. (2) Acute ease Appearing in a specific incident or observation to then be under the present influence of alcohol and/or drugs is reasonably suspected to be a contributing cause. Regardless of previous history, immediate action is necessary. (J.A. 1011). The Policy further enumerates the circumstances under which substance screening may be considered, which include, but are not limited to, the following: 1. Observed use, possession, or sale of illegal drugs and/or use, possession, sale, or abuse of alcohol and/or the illegal use or sale of prescription drugs. 2. Apparent physical state of impairment of motor functions. 3. Marked changes in personal behavior not attributable to other factors. 4. Employee involvement in or contribution to an accident where the use of alcohol or drugs is reasonably suspected or employee involvement in a pattern of repetitive accidents, whether or not they involve actual or potential injury. 5. Violations of criminal drug law statutes involving the use of illegal drugs, alcohol, or prescription drugs and/or violations of drug statutes. (J.A. 1011). The above circumstances under which substance screening may be considered “are strictly limited in time and place to employee conduct on duty or during work hours, or on or in Knox County Board of Education property, or at school system-approved or school related functions.” (J.A. 1011). 3. Testing Procedures Section.ll of the Policy describes the drug and alcohol abuse testing procedures. The Board has designated a physician as the MRO. The MRO is responsible for reviewing the results of drug tests before they are reported to the Board’s Director of Personnel; reviewing and interpreting each confirmed positive test to determine if there is an alternative medical explanation for the positive result; conducting an interview with the individual testing positive; reviewing the individual’s medical history and medical records to determine if the positive result was caused by legally prescribed medication; requiring re-test of the original specimen if the MRO deems it necessary; and verifying that the laboratory report and the specimen are correct. The MRO is expected to follow the Medical Review Officer’s Manual published by the U.S. Department of Health and Human Services. However, if the MRO determines that there is a legitimate medical explanation for the positive test other than the use of a prohibited drag, the MRO will conclude that the test is negative and take no further action. If the MRO concludes that a particular test is scientifically insufficient, the MRO will conclude that the test is negative for that individual. If the MRO determines that there is no legitimate explanation for the positive test other than the use of a prohibited drug, the MRO will communicate the test results as positive to the Director of Personnel. In the case of drag testing, urine specimens are to be collected in accordance with Department of Transportation Workplace Testing Programs, 49 C.F.R. part 40, with some exceptions. Procedures for collecting urine specimens shall allow privacy unless there is reason to believe that a particular individual may alter or substitute the specimen. The initial test performed on the urine at the laboratory will be an Enzyme-Multiplied Immunoassay Technique (EMIT) screen which will be used to eliminate negative urine specimens from further consideration. All specimens identified as positive on the initial test will then be confirmed using gas chromatography/mass spectrometry (GC/MS) techniques. With respect to the alcohol testing procedures, the Policy provides only that the Knox County Sheriffs Department will be requested to perform, and will be responsible for administering, a breath analysis test. If the breath analysis test is positive, a second breath analysis may be taken. The breath analysis test level to be considered positive will be .02. The alcohol urinalysis will be an EMIT screen followed by confirmatory gas chromatography tests on positive screens. Either test will be considered positive if the results are .04 or more. In contrast to the D.O.T. procedures — which contain detailed regulations concerning training for individuals who administer breathalyzers, standards for breathalyzer machines, and standards for administering the initial test — the Policy provides few guidelines regarding the administration of a breathalyzer test. Procedurally, the Policy describes the reasonable suspicion testing as follows: Once the determination has been made that an employee is to be tested based upon reasonable suspicion, the Director of Personnel should then transport the employee to the collection site, or make other appropriate arrangements for transportation. The collection site personnel should be notified that the reason for testing is reasonable suspicion. Upon arriving at the collection site, the employee will be asked to sign a release for testing and to assist in completing the necessary forms for testing. After the employee has signed the necessary releases for testing, then the standard procedures for drug and alcohol testing should be followed by the collection site personnel. Once the procedure has been completed, the employee should be transported back to the Director of Personnel’s office where the employee will be placed on administrative leave with pay until the results of the tests are available and given instruction to call the Director of Personnel each work day, before the normal reporting time for that employee, for further instructions. If the employee refuses to sign the release or refuses to be tested by NPL, the employee should be advised that refusal under the Board Policy is insubordination. If the employee continues to refuse, the employee should be transported back to the Director of Personnel’s office. The Director of Personnel will place the employee on administrative leave with pay with instructions to call his/her office before the normal reporting time for that employee on the following work day. If Director of Personnel feels that the employee is in no condition to operate a vehicle, then the employee should be transported home. * * * In the event of positive test results, the MRO will contact the Director of Personnel who will then review other records of the employee and contact the Knox County Law Director to work out proper disciplin- ‘ ary procedures, * * '*. (J.A. 46). The Policy recognizes that information regarding an individual’s drug testing results is confidential and “will be released by the MRO and the Director of Personnel only upon the written consent of the individual, except the results may be released and relied upon by the Knox County Board of Education in any administrative or court action by the employee involving the drug test, or any discipline resulting from a violation of this policy, including employment and court proceedings.” (J.A. 1016-17). The Policy further provides that the substance screens will be maintained by the MRO in a secure fashion and disclosed to the Director of Personnel only to the extent necessary to address any work-related safety risks occasioned by either the drug or alcohol use. All personnel records and information regarding referral, evaluation, substance screen results, and treatment are to be maintained in a confidential manner and no entries concerning such will be placed in the employee’s personnel file. In effect, two separate files will be maintained: one with the MRO indicating the results of the substance abuse tests and another maintained as part of the employee’s personnel record. Since the Board instituted its initial drug testing in December of 1989, four individuals have tested positive for drug/alcohol use: two teachers, one teacher applicant, and one employee in a non-safety-sensitive position. Three of those individuals were subject to drug testing on the basis of reasonable suspicion, and the other was subject to suspicion-less pre-employment drug testing. IV. DISTRICT COURT OPINION A. Suspicionless Testing The District Court applied the well-established balancing test to determine if the sus-picionless drug testing program was lawful: [Wjhere a Fourth Amendment intrusion serves special governmental needs, beyond the normal need for law enforcement, it is necessary to balance the individual’s privacy expectations against the Government’s interests to determine whether it is impractical to require a warrant or some level of individualized suspicion in the particular context. (J.A. 52) (quoting National Treasury Employees Union v. Von Raab, 489 U.S. 656, 665-66, 109 S.Ct. 1384, 103 L.Ed.2d 685 (1989)). Conducting the balancing test, the District Court found that the state’s asserted interest in insuring student safety was “diminished appreciably” by the lack of “evidence that the problem of drugfeleohol abuse by the persons tested” or any evidence of “a teacher or other employee responsible for children has allowed any harm or even a threat of harm to the children by being on the job in an impaired condition.” (J.A. 57). The District Court also found that even if a teacher was impaired on the job, he or she would not pose the same risk of “disastrous” harm that courts have previously deemed sufficient to justify subjecting individuals to suspicionless drug testing. (J.A. 57) (referring to Skinner v. Railway Labor Executives’Ass’n, 489 U.S. 602, 109 S.Ct. 1402, 103 L.Ed.2d 639 (1989) (railroad engineers) and Rushton v. Nebraska Public Power District, 844 F.2d 562 (8th Cir.1988) (nuclear power plant workers)). Turning to the issue of individual privacy, the District Court found the testing procedures were “fairly intrusive,” and infringed upon the legitimate expectations of privacy held by teachers and other professionals subject to the testing. (J.A. 58-59). The District Court rejected the argument that teachers had a “diminished expectation of privacy” because the provision of public education was heavily regulated by the state, reasoning that public education is not “an industry heavily regulated in terms of safety.” (J.A. 58-59). Balancing the intrusion on privacy that resulted from suspicionless testing against the state’s interest in such testing, the District Court concluded that the balance tilted heavily in favor of individual privacy interests. Thus, the District Court held that the suspicionless testing program violated the Fourth Amendment. B. Reasonable Suspicion Testing The District Court ruled that the reasonable suspicion drug testing program was constitutional but that the reasonable suspicion alcohol testing program was constitutionally flawed. 1. Drug Testing The District Court found that the Policy’s requirements of reasonable cause sufficiently limited the discretion of officials administering the rule and comported with the reasonableness requirement of the Fourth Amendment. This led the District Court to conclude that “the Policy’s reasonable suspicion testing procedures adequately protect the government’s interest in removing drug impaired employees from their jobs without invading their reasonable expectations of privacy.” (J.A. 62). 2. Alcohol Testing The District Court found that the standards in the alcohol testing procedure were inadequate to protect the privacy interests of tested employees. The lack of standards, in combination with the fact that the level for a positive test was extremely low (at just one-fifth of the level required to test positive for drunk driving under Tennessee law), raised the possibility that an individual might test positive simply as a result of legal, off-duty consumption of alcohol. Finally, the District Court was concerned that under the Policy a law enforcement officer administers the test, despite the fact that Defendant now has its own equipment. V. STANDARD OF REVIEW The ultimate question presented in this case is the reasonableness of a Fourth Amendment search, which is a question of law that we review de novo. United States v. Jones, 133 F.3d 358, 360 (5th Cir.1998) (“The ultimate determination whether the search or seizure was reasonable under the Fourth Amendment is reviewed de novo.”); United States v. Cantley, 130 F.3d 1371, 1375 (10th Cir.1997) (“The reasonableness of a search and seizure under the Fourth Amendment is a question of law we review de novo.”). The application of res judicata and collateral es-toppel are also questions of law that we review de novo. United States v. Real Property Known and Numbered as 415 East Mitchell Avenue, 149 F.3d 472, 476 (6th Cir.1998) (“We review de novo the applicability of collateral estoppel.”); Heyliger v. State University and Community College System of Tennessee, 126 F.3d 849, 851 (6th Cir.1997) (Court of Appeals reviews de novo a district court’s decision regarding collateral estoppel or res judicata). VI. ANALYSIS The Fourth Amendment safeguards the privacy of individuals against arbitrary and unwarranted governmental intrusions by providing that “[tjhe right of the people to be secure in their persons, houses, papers, and effects against unreasonable searches and seizures, shall not be violated”. However, “the Fourth Amendment does not proscribe all searches and seizures, but only those that are unreasonable.” Skinner, 489 U.S. at 619, 109 S.Ct. 1402 (cites omitted). The reasonableness of a search “depends upon all of the circumstances surrounding the search or seizure and the nature of the search or seizure itself.” United States v. Montoya de Hernandez, 473 U.S. 531, 537, 105 S.Ct. 3304, 87 L.Ed.2d 381 (1985) (citing New Jersey v. T.L.O., 469 U.S. 325, 337-342, 105 S.Ct. 733, 740-743, 83 L.Ed.2d 720 (1985)). It is now well-settled that drug testing which utilizes urinalysis is a “search” that falls within the ambit of the Fourth Amendment. See, e.g., Skinner, 489 U.S. at 617, 109 S.Ct. 1402 (the collection and testing of urine intrudes upon expectations of privacy in such a way “that these intrusions must be deemed searches under the Fourth Amendment.”). The Supreme Court jurisprudence in the area of drug testing is primarily reflected in four relatively recent decisions. Because an understanding of these cases is necessary to a meaningful analysis of the constitutionality of any drug testing regime, we briefly review those decisions. In Skinner v. Railway Labor Executives’ Association, 489 U.S. 602, 109 S.Ct. 1402, 103 L.Ed.2d 639 (1989), the Court considered the government’s interest in testing railroad employees for drugs and alcohol after a serious accident without a showing of individualized suspicion that drugs were involved. The Court began its analysis by noting that the “problem of alcohol use on American railroads is as old as the industry itself,” and that alcohol was the probable cause or a contributing factor in at least 21 significant accidents occurring between 1972 and 1983, resulting in 25 fatalities, 61 non-fatal injuries, and property damages estimated at over $19 million. It was against this backdrop that the Court evaluated the Federal Railroad Administration’s regulations which mandated post-accident toxicological testing for all employees involved in the accident, and led the Court to determine that the government’s interest in such testing was compelling because the “[ejmployees subject to the tests discharge duties fraught with risks of injury to others that even a momentary lapse of attention can have disastrous consequences.” Skinner, 489 U.S. at 628, 109 S.Ct. 1402. The Court also noted that: By ensuring that employees in safety-sensitive positions know they will be tested upon the occurrence of a triggering event, the timing of which no employee can predict with certainty, the regulations significantly increase the deterrent effect of the administrative penalties associated with the prohibited conduct, cf. Griffin v. Wisconsin, 483 U.S. at 876, 107 S.Ct. at 3170, concomitantly increasing the likelihood that employees will forgo using drugs or alcohol while subject to being called for duty. Skinner, 489 U.S. at 630, 109 S.Ct. at 1420. The avoidance of such calamities outweighed the employees privacy interests, which were “diminished by reasons of their participation in an industry that is regulated pervasively to ensure safety, a goal dependent, in substantial part, on the health and fitness of covered employees.” Skinner, 489 U.S. at 627, 109 S.Ct. 1402. Testing without a showing of a particularized suspicion was essential to the realization of a deterrent effect — i.e., the employee’s inability to avoid detection simply by staying drug-free at a prescribed test significantly enhanced the deterrent effect. In National Treasury Employees Union v. Von Raab, 489 U.S. 656, 109 S.Ct. 1384, 103 L.Ed.2d 685 (1989), which was decided the same day as Skinner, the Court upheld the United States Customs Service’s drug testing of employees seeking promotion or transfer to positions involved in the interdiction of illegal drugs, which required them to carry firearms. The Service’s drug testing regime was not prompted by a pronounced drug problem, but by its stature as the “Nation’s first line of defense against one of the greatest problems affecting the health and welfare of our population.” Von Raab, 489 U.S. at 668, 109 S.Ct. 1384. The Court stated that it was “readily apparent” that the Government has a compelling interest in ensuring that the Service maintained unimpeachable integrity and judgment, and cautioned against the possibility of grievous consequences associated with having drug-using agents: This national interest in self-protection could be irreparably damaged if those charged with safeguarding it were, because of their own drug use, unsympathetic to their mission of interdicting narcotics. A drug user’s indifference to the Service’s basic mission or, even worse,, his active complicity with the malefactors, can facilitate importation of sizable drug shipments or block apprehension of dangerous criminals. The public interest demands effective measures to bar drug users from positions directly involving the interdiction of illegal drugs. Von Raab, 489 U.S. at 670, 109 S.Ct. 1384. The Court further noted that “the public should not bear the risk that employees who may suffer from impaired perception and judgment will be promoted to positions where they. may need to employ deadly force.” Von Raab, 489 U.S. at 671, 109 S.Ct. 1384. Some six years later, in Vernonia School District 47J v. Acton, 515 U.S. 646, 115 S.Ct. 2386, 132 L.Ed.2d 564 (1995), the Court reaffirmed the basic principals outlined by Skinner and Von Raab. In Vemonia, a school district implemented a random drug testing of students who participated in school athletic programs. The policy was prompted by a rampant increase in drug use, exacerbated by student athletes who were leaders of the drug culture. This caused significant concern because drug use increases the likelihood of sports related injury. The school district responded by offering presentations and classes to prevent drug use, but to no avail. Finally, with disciplinary problems at epidemic proportions and with a large segment of the student body (especially those involved in athletics) in a state of rebellion, the school administration, at its wits end, enacted a drug testing program for student athletes. The Court upheld the drug testing, noting that “students within the school environment have a lesser expectation of privacy than members of the population generally!,]” Vernonia, 515 U.S. at 657, 115 S.Ct. 2386 (citing New Jersey v. TLO, 469 U.S. 325, 348, 105 S.Ct. 733, 83 L.Ed.2d 720 (1985)), and that school locker rooms are “not notable for the privacy they afford.” Vernonia, 515 U.S. at 657, 115 S.Ct. 2386. Additionally, student athletes’ expectation of privacy is reduced by their voluntary decision to “go out for the team,” thus subjecting themselves to a higher degree of regulation and physical scrutiny than other students. The Supreme Court most recently addressed the issue of drug testing in Chandler v. Miller, 520 U.S. 305, 117 S.Ct. 1295, 137 L.Ed.2d 513 (1997). In Chandler, candidates for high office in Georgia brought suit challenging the constitutionality of a statute which required candidates to submit to and pass a drug test within 30 days prior to qualifying for a nomination to qualify for certain state offices. Balancing the candidates’ privacy expectations against the State’s interest in drug testing them, the Court held the statute unconstitutional. Specifically, the Court held that the suspieionless testing did not meet the Fourth Amendment’s “special needs” exception to overcome the need for a individualized suspicion of wrongdoing. The Court’s decision rested in large part upon the lack of a demonstrated drug problem among state officeholders, which, while not necessary in all cases, would have shored up the assertion of a special need for a suspieionless general research program. Chandler, at -, 117 S.Ct. at 1303. Ultimately, this led the Court to conclude that the Fourth Amendment shielded against drug tests such as Georgia’s candidate drug test, which diminished “personal privacy for a symbol’s sake.” Chandler, at -, 117 S.Ct. at 1305. A. Suspieionless Testing As a general rule, in order to be reasonable, a search must be undertaken pursuant to a warrant issued upon a showing of probable cause. Skinner, 489 U.S. at 619, 109 S.Ct. 1402 (“Except in certain well-defined circumstances, a search or seizure in such a case is not reasonable unless it is accomplished pursuant to a judicial warrant issued upon probable cause.”). That is, a valid search must ordinarily be based on an “individualized suspicion of wrongdoing.” Chandler, at-, 117 S.Ct. at 1301. However, in Chandler the Court clarified how suspieionless testing — presumably inherently suspect because by definition it is not accompanied by individualized suspicion — can comport with the Fourth Amendment: But particularized exceptions to the main rule are sometimes warranted based on “special needs, beyond the normal need for law enforcement.” Skinner, 489 U.S. at 619, 109 S.Ct. at 1414 (internal quotation marks omitted). When such “special needs” — concerns other than crime detection — are alleged in justification of a Fourth Amendment intrusion, courts must undertake a context-specific inquiry, examining closely the competing private and public interests advanced by the parties. See Von Raab, 489 U.S. at 665-66, 109 S.Ct. at 1390-91; see also id. at 668, 109 S.Ct. at 1392. As Skinner stated: “In limited circumstances, where the privacy interests implicated by the search are minimal, and where an important governmental interest furthered by the intrusion would be placed in jeopardy by a requirement of individualized suspicion, a search may be reasonable despite the absence of such suspicion.” 489 U.S. at 624, 109 S.Ct. at 1417. Chandler, at-, 117 S.Ct. at 1301. Thus, where a Fourth Amendment intrusion serves special needs, “it is necessary to balance the individual’s privacy expectations against the Government’s interests to determine whether it is impractical to require a warrant or some level of individualized suspicion in the particular context.” Von Raab, 109 S.Ct. at 1390. Quite simply, then, in evaluating the constitutionality of the Board’s drug testing Policy here, we must balance the government’s (or public’s) interest in testing against the individual’s privacy interest. 1. Public Interest in Testing With regard to the government’s interest in testing, the Supreme Court has traditionally focused its analysis on two central factors: (1) whether the group of people targeted for testing exhibits a pronounced drug problem; and, if not, whether the group occupies a unique position such that the existence of a pronounced drug problem is unnecessary to justify suspieionless testing; and (2) the magnitude of the harm that could result from the use of illicit drugs on the job. The existence of a pronounced drug problem within the group of employees targeted for testing typically tips the equities in favor of upholding suspicionless testing. For example, in Skinner the Court traced the history of drug and alcohol abuse among train operators and in Vemonia emphasized the rampant increase in drug use among students participating in school athletic programs — in both cases the existence of a pronounced drug problem contributed to the Court’s upholding of the drug testing regimes. Likewise, in Chandler, the Court stated that the lack of a demonstrated drug problem among state officeholders in Georgia mitigated against allowing an unintrusive drug testing requirement. Thus, as would be expected when using a balancing test, in cases in which a pronounced drug problem exists within the target group, a drug testing regime has a higher likelihood of being deemed constitutional because the more pernicious the drug problem is, the greater the public’s interest is in abridging it. In this case, there is little, if any, evidence of a pronounced drug or alcohol abuse problem among Knox County’s teachers or other professional employees. Specifically, there is no empirical or historical evidence of an ongoing abuse problem (as in Skinner) or evidence of a newly blossoming epidemic of abuse (as in Vemonia). In fact, since the Policy was implemented in 1989, only one prospective hire has failed the sus-picionless drug test. However, the existence of a pronounced drug problem is not a sine qua non for a constitutional suspieionless drag testing program. The Board argues that there is no indication that teachers are unaffected by the drag use affliction that affects our country as a whole, and that proof of a pronounced drag problem is unnecessary. The Board’s argument relies heavily on Von Raab, in which the Court upheld a suspicionless drug testing program in the absence of a drug problem among Customs Service agents. In Chandler, the Court explained that Von Raab was based on a unique set of circumstances: Hardly a decision opening broad vistas for suspicionless searches, Von Raab must be read in its unique context. As the Customs Service reported in announcing the testing program, “[Customs employees], more than any other Federal workers, are routinely exposed to the vast network of organized crime that is inextricably, tied to illegal drag use.” National Treasury Employees Union v. Von Raab, 816 F.2d 170, 173 (C.A.5 1987) (internal quotation marks omitted), aff'd. in part, vacated in part, 489 U.S. 656, 109 S.Ct. 1384, 103 L.Ed.2d 685 (1989). We stressed that “[d]rag interdiction ha[dj become the agency’s primary enforcement mission,” id. at 660, 109 S.Ct. at 1387-88, and that the employees in question would have “access to vast sources of valuable contraband,” id. at 669, 109 S.Ct. at 1392-93. Furthermore, Customs officers “ha[d] been the targets of bribery by drug smugglers on numerous occasions,” and several had succumbed to the temptation. Ibid. Respondents overlook a telling difference between Von Raab and Georgia’s candidate drug-testing program. In Von Raab it was “not feasible to subject employees [required to carry firearms or concerned with interdiction of controlled substances] and their work product to the kind of day-to-day scrutiny that is the norm in more traditional office environments.” Id. at 674, 109 S.Ct. at 1395. Candidates for public office, in contrast, are subject to relentless scrutiny — by then-peers, the public, and the press. Their day-to-day conduct attracts attention notably beyond the norm in ordinary work environments. Chandler, at-, 117 S.Ct. at 1304. Just as the Customs agents in Von Raab must be considered in their own unique context, so too must the nature of the work and positions of school teachers and administrators be viewed as unique. We can imagine few governmental interests more important to a community than that of insuring the safety and security of its children while they are entrusted to the care of teachers and administrators. Concomitant with this governmental interest is the community’s interest in reasonably insuring that those who are entrusted with the care of our children will not be inclined to influence children — either directly or by example — in the direction of illegal and dangerous activities which undermine values which parents attempt to instill in children in the home. Indeed, teachers occupy a singularly critical and unique role in our society in that for a great portion of a child’s life, they occupy a position of immense direct influence on a child, with the potential for both good and bad. Teachers and administrators are not simply role models for children (although we would certainly hope they would be that). Through their own conduct and daily direct interaction with children, they influence and mold the perceptions, and thoughts and values of children. Teachers and administrators are not some distant societal role models, as in the case of the Georgia political candidates in Chandler, rather, on a daily basis, there is a direct nexus between the jobs of teachers , and administrators and the influence they exert upon the children who are in their charge. Indeed, directly influencing children is their job. The State of Tennessee has recognized and-codified this role and obligation in TCA § 49-6-4203(b), which states that teachers shall serve in an in loco parentis capacity and are charged with the responsibility “to secure order and to protect students from harm while in their custody.” Thus, by operation of law, during school hours and at school related events, teachers stand in the place of students’ natural parents and are responsible for their safekeeping. The existence of this duty is itself “unique” to school teachers and administrators, and, we believe, is, by itself, great enough to overcome the presumption against suspieionless testing. While serving in their in loco parentis capacity, teachers are on the “frontline” of school security, including drug interdiction. (J.A. 937; Griffin Dep., 162). While teachers may not be exposed to a vast network of organized crime in this capacity, they are faced with pervasive drug use in our schools, and are perhaps in the best position to determine if a child is either in danger or involved with drugs. Indeed, a compilation of incidents in the Knox County school system reveals that there were 77 documented occurrences of substance abuse in 1996. That figure does not include, of course, all of the incidents that went undetected. In most cases, teachers and other school officials are responsible for reporting the prohibited activity. (J.A. 943; Griffin Dep., 168) (“If it weren’t for the teachers we wouldn’t have these .reports in front of us.”). Thus, unlike candidates for public office who may indirectly affect the lives of children as role models and policymakers, teachers directly influence and supervise children daily. In further distinguishing Chandler, we also observe that teachers are not subject to the same day-to-day scrutiny as are candidates for public office, which would,, at least to some extent, mitigate the need for suspicion-less testing. Like Custom’s agents, teachers do not work in an ordinary work environment in which they are constantly scrutinized by their peers and others; rather, they spend most of their days (about 6 hours) in the solitude of their classrooms surrounded only by students, some of whom are very young, who may or may not be able to detect drug use among teachers. Even if a student did detect drug use by a teacher, that student would likely be wary of reporting such conduct for fear of being disbelieved, ridiculed, or retaliated against. In short, although the record evidence does not reflect that the Knox County District school teachers and other such officials have a track record of a pronounced drug problem, the suspicionless testing regime is justified by the unique role they play in the fives of school children and the in loco paren-tis obligations imposed upon them. The second factor we must consider in the balancing test analysis focuses on the magnitude of harm that could result from the use of illicit drugs in any given set of circumstances. In this case, the public interest proffered by the Board is that teachers, principals, and other such school personnel hold safety-sensitive positions and that the school district has a legitimate and strong interest in safeguarding the health and welfare of its students by ensuring that people in safety-sensitive positions are not under the influence of drugs or alcohol at school.' The validity of this argument hinges in large part upon whether or not teachers, principals, and the other school officials covered by the testing actually occupy “safety-sensitive” positions. As a threshold matter, the Court rejects the Board’s assertion that the issue of whether teachers are safety-sensitive employees has already been decided in its favor in prior litigation between the parties, and that res judicata and collateral estoppel bar the re-litigation of that issue. The doctrine of res judicata or claim preclusion states that a final and valid judgment on the merits of a claim precludes subsequent action on that claim. The doctrine precludes re-litigation on claims actually litigated as well as claims that could have been litigated. Richards v. Jefferson County, Ala., 517 U.S. 793, 797 n. 4, 116 S.Ct. 1761, 1765 n. 4, 135 L.Ed.2d 76 (1996)( “The doctrine of res judicata rests at bottom upon the ground that the party to be affected, or some other with whom he is in privity, has litigated or had an opportunity to litigate the same matter in a former action in a court of competent jurisdiction.”); Heyliger v. State University and Community College System of Tennessee, 126 F.3d 849, 852 (6th Cir.1997). Under the doctrine of collateral estoppel, once an issue is actually and necessarily determined by a court of competent jurisdiction, that determination is conclusive in subsequent suits based on a different cause of action involving a party to the prior litigation. Montana v. United States, 440 U.S. 147, 153, 99 S.Ct. 970, 59 L.Ed.2d 210 (1979). In December of 1989, the Defendant Board of Education adopted a “Drug-Free Workplace Policy,” which was revised several times over the course of the next two and a half years. In 1991, Plaintiff in the instant case, KCEA, filed suit challenging the policy on Fourth Amendment grounds (“KCEA I”). In that case, the district court noted that the policy did not describe the methods or procedures to be followed in obtaining or testing urine samples, nor did it assure the employee applicants that their privacy interests in the results would be protected. This led the court to conclude: “Because the privacy interests of the professional employee applicants in this case are not protected at all by the policy as it is written, the court finds that for this reason alone the policy must fail constitutional examination.” (J.A. 282) (emphasis added). However, the court did not end its inquiry at that point. The court addressed the second part of the balancing test to examine whether the governmental interests were strong enough to test all professional employees, irrespective of the nexus their position had to the safety of the children. The court then found that of the professional employee positions subject to pre-employment drug screening, principals (and assistant principals), teachers (and traveling teachers), teacher aids, and school secretaries occupied safety sensitive positions because “[a]ny lapse in attention or judgment on the part of these employees could result in an immediate threat to a child’s safety.” (J.A. 284-85). This led the court to conclude: Thus, even if the policy adequately protected the privacy interests of the professional employees, and the court finds that it does not, the only professional employees which the court considers subject to pre-employment testing are principals, assistant principals, teachers, traveling teachers, teacher aids, and school secretaries. (J.A. 287) (emphasis added). Despite the fact that the district court continued its inquiry to include an analysis of which employees qualified as safety sensitive, it is obvious that this determination was not necessary to the ruling finding the drug testing scheme unconstitutional. In order to find that either doctrine bars the re-litigation of an issue, the issue must have been “necessary to support the judgment entered in the prior proceeding.” NLRB v. Master Slack, 773 F.2d 77, 81 (6th Cir.1985). See also, Marlene Industries Corp. v. NLRB, 712 F.2d 1011, 1015-16 (6th Cir.1983) (“The determination of an issue in an earlier proceeding must be essential to the judgment; it cannot be dicta.”) (citing Anthan v. Professional Air Traffic Controllers Org., 672 F.2d 706, 710 (8th Cir.1982)). The district court clearly ruled that because the privacy interests of the employee were not protected at all by the drug testing scheme as it existed at that time that the testing was unconstitutional. By the court’s own statement, that reason alone was sufficient to render the scheme unconstitutional, and any further explanation of its unconstitutionality was gratuitous and constitutes dicta. The court reiterated the alternative nature of the ruling when it stated that “even if the policy adequately protected the privacy interests of professional employees, and the court finds that it does not, the only professional employees which the court considers subject to pre-employment testing are principals, assistant principals, teachers, traveling teachers, teacher aids, and school secretaries.” (J.A. 287). Clearly, then, the court’s ruling on which employees occupied safety-sensitive positions was not essential to the disposition of the case, and, therefore, cannot preclude Plaintiff from. litigating that issue in this case. Thus, the Court must proceed in making its own determination of whether teachers and other school administrators occupy safety-sensitive positions, Under Skinner, the test for whether employees hold safety sensitive positions is whether the employees “discharge duties fraught with risks of injury to others that even a momentary lapse of attention can have disastrous consequences.” Skinner, 489 U.S. at 628, 109 S.Ct. 1402. In Skinner, which involved drug testing for railroad engineers, the Court stated that a locomotive “becomes lethal when operated negligently by persons who are under the influence of alcohol or drugs,” and that drug use among these employees “can cause great human loss before any signs of impairment become noticeable to supervisors or others.” Skinner, 489 U.S. at 628, 109 S.Ct. 1402. Courts have found similar risks inherent in several other positions, including: nuclear power plant workers, seamen operating oil tankers, a meter repairman for a gas company, a firefighter and emergency medical technician , a process technician at a petro-refin-ing facility, police officers, a bus driver, and pipeline operators. Thus, in order to show that school teachers and administrators also occupy safety-sensitive positions, the Board must demonstrate a “clear, direct nexus ... between the nature of the employee’s duty and the nature of the feared violation.” Georgia Association of Educators v. Harris, 749 F.Supp. 1110, 1115 (N.D.Ga.1990) (quoting Hannon v. Thornburgh, 878 F.2d 484, 490 (D.C.Cir.1989), cert. den. sub. nom., Bell v. Thornburgh, 493 U.S. 1056, 110 S.Ct. 865, 107 L.Ed.2d 949 (1990)). Although the position of school teacher may not fit neatly into the prototypical “safety-sensitive” position, we do not read the definition of “safety-sensitive” so narrowly as to preclude application to a group of professionals to whom we entrust young children for a prolonged period of time on a daily basis. Simple common sense and experience with life tells us “that even a momentary lapse of attention can have disastrous consequences,” Skinner, 489 U.S. at 628, 109 S.Ct. 1402, particularly if that inattention or lapse were to come at an inopportune moment. (See testimony of Grant at J.A. 958-59; Sta-ley at J.A. 996-98). For example, young children could cause harm to themselves or others while playing at recess, eating lunch in the cafeteria (if for example, they began choking), or simply while horsing around with each other. Children, especially younger children, are active, unpredictable, and in need of constant 'attention and supervision. Even momentary inattention or delay in dealing with a potentially dangerous or emergency situation could have grievous consequences. This is equally true of teaching at the high school level. Not only must teachers observe and report drug use, but they are also charged, by law, with reporting assaults as well. TCA § 49-6-4301(a) provides that “[e]very teacher observing or otherwise having knowledge of an assault and battery ór vandalism endangering life, health or safety committed by a student on school property shall report such action immediately to the principal of the school.” Fifty such incidents occurred in Knox County schools in the 1995-96 school year, and 77 in the 1994-95 school year. The Court believes that a local school district has a strong and abiding interest in requiring that teachers and other school officials be drug-free so that they can satisfy their statutory obligation to insure the safety and welfare of the children. The fact that the Board has not been able to cite any one specific example in which a teacher or other employee responsible for children has allowed any harm to the children by being in an impaired condition while on the job is certainly not dispositive of the question of whether teachers and administrators hold “safety-sensitive” positions. We do not believe that the Board must wait passively for a disaster to occur before taking preemptive action to minimize the risks of such an occurrence. Indeed, we have no doubt that if a tragedy were to befall one or more of the school children of Knox County that in some manner implicated a teacher or administrator being under the influence of an illegal substance, the members of that community would rightly question why the Board had not taken all efforts possible in advance to prevent such an occurrence. Finally, we would be remiss if we did not point out that the safety sensitive nature of a teacher’s or administrator’s job is not limited to the necessity to act at the immediate time of a dangerous event. Rather, school personnel perform an essential monitoring role in preventing incidents from occurring in the first place. Teachers and administrators are in a unique position to observe children and learn if they are involved in activities which can lead to harm or injury to themselves or others. Clearly, if school personnel are themselves under the influence of, or involved in, drugs, their ability to perform this critical function is not only reduced, but they themselves are open to being compromised and undermined. Clearly, a school board has a very strong interest in preventing this as part of its responsibility to insure the safety and security of school children. 2. Privacy Interest of Employees Having ruled that the public interest in suspicionless testing is very strong, an analysis of the employee’s privacy rights is necessary to determine which of the competing values should prevail in this case. As will become evident in the course of this analysis, because teachers’ legitimate expectation of privacy is diminished by their participation in a heavily regulated industry and by the nature of their job, the public interest in suspicionless testing outweighs that private interest. Again, we read the Supreme Court precedents assessing the privacy interests of employees as focusing on two central factors: (1) the intrusiveness of the drug testing scheme; and (2) the degree to which the industry in question is regulated. We begin by noting that drug testing does implicate the privacy interests of employees on several levels. As the Supreme Court noted in Skinner, urination is an intensely private and personal act. Skinner, 489 U.S. at 617, 109 S.Ct. 1402 (“There are few activities in our society more personal or private than the passing of urine.”). Th