OPINION
€ 1 Thе City of South Jordan (the City or South Jordan) appeals from the trial court's order granting partial summary judgement in favor of Daniel Pearson. The trial court concluded that South Jordan could not terminate Pearson's employment without meeting the procedural requirements afforded to certain public employees under Utah Code see-tions 10-38-1105 and 10-83-1106. See Utah Code Ann. §§ 10-38-1105 to -1106 (2007). 1 We reverse and remand for proceedings consistent with this opinion.
BACKGROUND
12 This dispute arises from the January 30, 2007 termination of Pearson from his position as assistant police chief of South Jordan. Pearson had held the post since July 2002. The City claimed that Pearson was an at-will employee and thus could "be terminated at any time, with or without causе or explanation." Pearson was offered a severance package in exchange for his resignation. When Pearson refused to resign, the City terminated his employment without stating a reason.
3 Because at-will employees are not entitled to administrative review through the City's Employee Appeals procedure, Pearson challenged the City's classification of him as such. After the City's Employee Appeals Board (the Board) upheld his at-will status and termination, Pearson appealed directly to this court. See Pearson v. South Jordan Emp. Appeals Bd.,
T4 Consistent with our decision, Pearson filed a complaint in the third district court in West Jordan on August 17, 2009. The complaint included a request for declaratory judgment regarding his employment status and claims for breach of written and oral contract, promissory estoppel, and unjust enrichment. Subsequently, Pearson filed a motion for partial summary judgment on the issue of whether state law allowed the City to classify an "assistant police chief" as an at-will employee. See Utah Code Ann. § 10-3-1105 (2007). 2 The City opposed Pearson's motion and countered with a cross-motion for partial summary judgment, asking the trial court to conclude that Peаrson could be terminated at-will under section 10-38-1105.
T5 After oral arguments, the trial court issued a memorandum decision, granting partial summary judgment in favor of Pearson. The trial court determined that, according to the dictionary, a "deputy" is a "substitute with power to act" or one who "usu[ally] takes charge when his or her superior is absent." See Merriam-Webster's Collegiate Dictionary 336 (11th ed. 2004). In contrast, "assistant" is defined as merely a helper. See id. at 74. The trial court reasoned that the statute's exemption of both "a deputy or assistant fire chief" but only "a deputy police chief" indicated a legislative intent to use the two terms to identify different positions within a city department. It then concluded that because the City did not assign Pearson the *1039 title "deputy police chief," it could not treat him as an at-will employee. We granted the City's petition for interlocutory appeal of that decisions. 3
ISSUE AND STANDARD OF REVIEW
16 South Jordan challenges the trial court's partial summary judgment in favor of Pearson on the ground that section 10-8-1105 of the Utah Code does not require the City to classify its assistant police chief as a merit employee. " '[SJummary judgment is appropriate only when there are no genuine issues of material fact and the moving party is entitled to judgment as a matter of law.'" Knight v. Salt Lake Cnty.,
ANALYSIS
T7 South Jordan raises two issues before this court in support of its argument that the trial court incorrectly granted partial summary judgment in favor of Pearson. To begin, the City argues that the trial court inappropriately applied the version of section 10-3-1105 in effect when Pearson was fired in 2007, rather than the version in effect when Pearson was hired in 2002. Alternatively, the City argues that the trial court erred in its interpretation of the 2007 version of the code because "deputy" should be read to mean "second-in-command."
18 We first determine that South Jordan did not preserve the issue of whether the trial court should have applied the earlier version of the statute. We then conclude that the trial court did not plainly err in applying the then-current version of the statute. Next, we depart from the trial court's interpretation of the then-current statute, in part. While we agree that the Utah Legislature intended the terms "assistant" and "deputy" to have different meanings, we hold that it is the seope of a municipal employee's responsibilities, rather than the employee's specific job title, that governs whether the City may terminate the employee at-will.
I. The Trial Court Did Not Plainly Err in Applying the Then-Current Statute
T9 Pearson was hired in July 2002, as the assistant police chief of South Jordan. At that time, section 10-8-1105 allowed municipalities to define аll "members of the police departments" as at-will employees subject to termination without meeting the requirements of section 10-38-1106 (the 1999 Act). See Utah Code Ann. § 10-38-1105 (1999) In 2004, the Utah Legislature amended the statute to provide that all public employees must be afforded the process provided by section 10-83-1106, unless their position is included on the list contained in section 10-3-1105(2) (the 2004 Act). See Utah Code Ann. § 10-3-1105 (2007). Those statutory exceptions include the municipality's "police chief" and "deputy police chief," but do not include an "assistant police chief" See id. § 10-3-1105(2).
T10 Thus, the terms of the 1999 Act, in effect when the City hired Pearson, unambiguously allowed South Jordan to fire him without providing the procedural protections of section 10-38-1106. Sеe Utah Code Ann. § 10-38-1106 (2007). With the 2004 amendments, however, the City's right to terminate Pearson at-will was limited by whether his job fell within one of the positions enumerated in section 10-8-1105(2). See id. § 10-3-1105. According to the City, the 1999 Act should govern this dispute because Pearson's statutory due process rights were fixed at the time of hiring, and because applying the 2004 Act retroactively would negatively af-feet the City's substantive right to fire Pearson at-will.
*1040 A. South Jordan Did Not Preserve Its Argument that the 1999 Act Should Apply
111 South Jordan did not raise in the trial court its argument that determining Pearson's status under the 2004 Act would result in the improper retroactive application of substantive amendments to the statute. To be preserved for appeal, an "issue must be presented to the trial сourt in such a way that the trial court has an opportunity to rule on that issue." Normandeau v. Hanson Equip., Inc.,
T12 In asserting that this issue is preserved, the City points generally to its statements to the trial court that when it hired Pearson in 2002, he was an at-will employee under the 1999 Act. See generally Utah Code Ann. § 10-3-1105 (1999) (providing that "[alll appointive officers and employees of municipalities, other than members of the police departments ... shall ... b[el subject to discharge or dismissal only as hereinafter provided"). However, we could find nothing in the record to indicate that the City argued to the trial court that the statute in effect in 2002 should govern Pearson's termination in 2007. While South Jordan provided factual background that the 1999 Act was in effect when Pearson was hired and would have allowed the City to terminate his employment at-will at that time, it did not ask the trial court to use the 1999 Act to resolve the issues relating to Pearson's termination. Instead, South Jordan focused its arguments to the trial court entirely on the language of the 2004 Act, referring to the 1999 Act only as "the predecessor statute to the one we're looking at." Because the issue was not presented in a way that the trial court had an opportunity to rule on it, the issue is unpre-served. See Normandeauy,
B. Any Assumed Error in Applying the 2004 Act Was Not Plain
113 The City contends that it should have been plain to the trial court that applying the 2004 Act was erroneous due to the general bar on the retroactive application of laws. To establish plain error, the City must establish three elements:
First, [it] must establish that an error did in fact occur. Second, [it] must establish that the error should have been obvious to the trial court. Third, the [City] must establish that the error was harmful, ie., that there is a reasonable likelihood that [it] would have enjoyed a more favorable outcome absent the error.
King,
114 For purposes of our analysis we assume without deciding that the trial court erred. Thus, we must first address the element of obviousness. "To establish that the error should have been obvious to the trial court, [the City] must show that the law governing the error was clear at the time the alleged error was made." State v. Dean,
115 The City first argues that settled law provides that Pearson's statutory rights are limited to those existing when he was hired. However, none of the authority cited by the City supports that assertion. Instead, South Jordan points us to several cases in which an employee was unable to assert a right at termination because the employee enjoyed no contractual or statutory right to continued employment. Seq eg., Board of Regents v. Roth,
116 Nor are we convinced that it should have been obvious to the trial court that Pearson's initial employment is the proper focus in determining which version of the Act governs. While we agree that courts have generally refused to apply substantive changes to the law retroactively, see generalty Kingsford v. Salt Lake City Sch. Dist.,
17 Therefore, we are not convinced that it should have been apparent to the trial court that the application of the 2004 Act was erroneous, or that applying the 2004 Act would retroactively impact South Jordan. Because South Jordan has not established plain error, we do not reach the merits of its assertion that Pearson's rights should be determined under the 1999 Act.
II. The City Was Not Required by Statute to Treat Pearson as a Merit Employee
118 When interpreting a statute we look first to its plain language. "We read the plain language of the statute as a whole[ ] and interpret its provisions in harmony with other statutes in the same chapter and related chapters." LPI Servs. v. McGee,
A. The Trial Court Correctly Distinguished "Deputy" from "Assistant"
119 Section 10-8-1105(1) provides that "[elxeept as provided in [sJubsection (2), each employee of a municipality shall hold *1042 employment without limitation of time, being subject to discharge ... only as provided in [slection 10-38-1106." See Utah Code Ann. § 10-3-1105 (2007). Section 10-38-1106 affords discharged employees the right to appeal the termination of their employment to an appeals board. See id. § 10-3-1106. However, subsection (2) of section 10-38-1105 provides a list of high-level positions, including "a deputy police chief," that are exempt from the requirement that a municipality make the administrative process of section 10-3-1106 available upon dischargе. See id. § 10-3-1105(2)(d). As the trial court correctly noted, the legislature's use of "a deputy or assistant fire chief," but only "a deputy police chief" indicates a legislative intent to distinguish the terms "deputy" and "assistant" as used in section 10-38-1105.
T20 We are also in agreement with the trial court's assessment of the different common meanings of the two terms. A deputy is "[a] person appointed or delegated to act as a substitute for another, esp[ecially] for an official." Black's Law Dictionary 507 (9th ed. 2009). An assistant, on the other hand, is "a person who assists" or a "helper." See Merriam-Webster's Collegiate Dictionary 74 (11th ed. 2004). Other jurisdictions that have defined "deputy" have done so in accordance with this definition. See, eg., Wilbur v. Office of the City Clerk,
$21 Utah courts have not explicitly defined "deputy," but cases that have considered the term have treated it consistently with the definition applied in other jurisdictions. For example, our supreme court held that an employee of the auditor's office had to meet statutory requirements before the employee could act as a deputy auditor with the authority to conduct a tax sale in place of the auditor. See Page v. McAfee,
B. The 2004 Act Is Ambiguous with Respect to the Proper Interpretation of Section 10-3-1105(2)
122 Pearson argues that because the exceptions in subsection (2) include "deputy police chief" but not "assistant police chief," the plain language of section 10-8-1105(2)(d) required the City to treat him as a merit employee entitled to administrative review. See Utah Code Ann. § 10-38-1105. Pointing to the exemption for both "deputy" and "assistant" fire chiefs in section 10-3-1105(2)(f), Pearson argues that the legislature would have incorporated "assistant police chief" into the list if it had intended to exempt that position. See id.
123 In response, South Jordan asserts that the statute does not require a municipality to use the precise title listed so long as the employee it treats as at-will performs the same functions as would a person described by one of the enumerated titles. Where Pearson was performing the functions of the second-in-command of the police department, the City reasons that it could fire him without adhering to the procedure provided by section 10-38-1106.
24 Because each of these interpretations is plausible, we conclude that the statute is ambiguous. See Marion Energy, Inc. v. KFJ Ranch P'ship,
C. Employees Who Perform the Substantive Duties of the Roles Listed in Section 10-38-1105 Are Exempt
125 The trial court held that only employees with the exact job titles enumerated in section 10-83-1105 are excluded from the mandatory process affоrded by section 10-3-1106, regardless of their actual duties. Pearson argues that such an interpretation provides employees with certainty as to their statutory merit status by simply comparing their job title to the statutory list. While recognizing the ease of application provided by the trial court's ruling, we also acknowledge the danger that an employee who does not actually function at the high level expected of those subject to termination at-will could lose merit status simply because the municipality has assigned him a title on the section 10-3-1105(2) list. Furthermore, we are convinced that a review of the employee's actual duties is consistent with our recent decision in Kocherhans v. Orem City,
126 In Kocherhans, Orem's treasury division manager, who had been terminated for cause, brought an action directly in the district court for wrongful termination after the Orem Employee Appeal Board upheld his discharge. See id. 18. Orem then moved to dismiss the complaint based on the failure to exhaust the administrative remedies provided in section 10-3-1106(6)(a), which required him to appeal to the Utah Court of Appeals. In response, Kocherhans argued that he was exempt from that process as an "at-will head of a department or deputy to a head of a department" under section 10-3-1105(2). See id. 1 4. To determine whether the failure to exhaust the section 10-3-1106 remedies divested the district court of subject matter jurisdiction, this court first had to decide whether Kocherhans was a merit or an at-will employee. See id. 1% 6-9.
1 27 In undertaking that analysis, we noted that "[slection 1105 sets up a presumption that most employees of municipalities within the state will be merit employees who can be terminated only for cause and have recourse to an administrative process." Id. 17. However, this court also acknowledged that municipalities are not bound to provide these procedural protections to "the most senior management positions" listed in section 10-3-1105(2). Id. The Kocherhans court observed that this statutory scheme provides most municipal employees stability and thus, "incentive to advance their careers ... without fear of arbitrary termination," thereby preventing a " 'spoils system' of governance that brings with it the variety of ills that accompany the threat of massive turnover of city employment with each change of municipal administration." See id. €10. At the same time, the statute allows a municipality to terminate top-level employees without cause, thus "preserv[ling] the ability of a new administration, once elected, to ensure that a municipality's core leadership positions are staffed with men and women of its own choosing." See id.
1 28 In addition, the Kocherhans court explained that by declining to define "deputy" or the other positions listed in section 10-3-1105(2), "the legislature appears to give each municipality considеrable discretion to organize and structure its workforce as it deems best to implement its governmental functions and serve its citizenry." See id. Indeed, the Utah Municipal Code itself dictates that "[the powers herein delegated to any munic
*1044
ipality shall be liberally construed to permit the municipality to exercise the powers granted by this act except in cases clearly contrary to the intent of the law." Utah Code Ann. § 10-1-103 (2007) (cited in Kocherhans,
T29 Relying on Orem's employee manual, the panel concluded that Orem "uses the term 'Department Director' in a manner that makes it equivalent to section 1105's 'head of a municipal department."" See Kocherhans v. Orem City,
T 30 Thus, to determine Pearson's employment status, we must first consider whether his duties were equivalent to those of a deputy police chief. If so, the City. could treat him as an at-will employee under section 10-3-1105(2). Otherwise it was required under section 10-8-1105(1) to afford him the procedural protections set forth in section 10-3-1106. See id.; see also Utah Code Ann. §§ 10-38-1105 to -1106.
D. Pearson's Duties Fit the Definition of Deputy
131 The City's organizational chart lists the "assistant chief of police" as second-in-command to the "chief of police." 6 According to a job description revised in 2004, the assistant police chiefs duties include "[als-sum[ing] departmental responsibility in the absence of Chief of Police." Among other duties, the assistant chief "[pJrovides general supervision to all department personnel"; assists in budget preparation, personnel matters, implementing quality control guidelines; "[dJevelops in-house training curriculum"; and "represent[s the} Police Department at public meetings as necessary." While not contesting the City's description of his actual duties, Pearson claims that he never received a written job description. According to *1045 Pearson's testimony before the Board, 7 general duties were discussed when he was hired, but South Jordan had not finalized a written job description at that time. In particular, Pearson refers to a letter from the City offering him the position, that states a job description will be provided at orientation, but that "in brief, you will be responsible for Police operations."
32 In response, South Jordan relies on the testimony of City Manager Riсk Horst, indicating that Pearson "took charge" and "was responsible for all operations of the City in the absence of the chief" Horst further testified that Pearson handled personnel matters, including hiring and firing recommendations, conducting performance evaluations, and making policy decisions. While Pearson did not dispute most of this testimony, he argued at the summary judgment hearing that there was no evidence that he made any policy decisions. However, this factual dispute is not material to our decision because Pearson was not required to make policy decisions in order to perform the duties of a deputy. See infro 133. Based on the undisputed facts, Pearson did not act as a mere assistant, or helper, to the police chief, Despite his title, Pearson had the power to act in place of the police chief and often did so. Therefore, we conclude that Pearson's duties were equivalent to those of a deputy and that South Jordan was not required to make the procedural requirements of section 10-83-1106 available to him. 8
183 Nonetheless, Pearson argues that he was not a "deputy" because he was not authorized to perform every function of the police chief. Aside from the ability to make policy decisions, Pearson has not identified any specific function that he did not have the authority to perform. Furthermore, there is no requirement that a deрuty be authorized to perform every function of the principal, so long as he can act in most significant respects in the principal's absence. Cf. Meyers v. Second Judicial Dist. Court,
1 34 Pearson further argues that this case is distinguishable from Kocherhans v. Orem City,
III. Several Issues that Must Be Resolved on Remand
1 35 In an attempt to assist the trial court, we briefly address Pearson's claim that he was contractually entitled to merit status. See State v. White,
{36 Nothing in this decision is intended to suggest that a municipality may not prоvide more protection than is required to those employees who are exempted from the mandatory process provided in section 10-3-1105(1). See Utah Code Ann. § 10-38-1105; see also Utah Pub. Emps. Ass'n v. State,
137 Indeed, municipalities are generally free to create rules and regulations "that may potentially create obligations towards employees in addition to those imposed by state law." Canfield v. Layton City,
CONCLUSION
138 Pearson performed duties equivalent to those of a "deputy police chief," and therefore, South Jordan was not required to provide him with the procedural protections set forth in section 10-38-1106. We accordingly reverse the trial court's partial summary judgment in favor of Pearson, and remand to the third district court for entry of partial summary judgment in favor of South Jordan, and for further proceedings to resolve Pear *1047 son's remaining claim that the City contracted to treat him as a merit employee.
T 39 Reversed and remanded.
I 40 WE CONCUR: JAMES Z. DAVIS and WILLIAM A. THORNE, JR., Judges.
Notes
. Because of substantive amendments made during the 2012 legislative session, we cite to the version of the Utah Code Annotated in effect at the time of Pearson's dismissal.
. Utah Code section 10-3-1105 reads in pertinent part:
(1) Except as provided in [sJubsection (2), each employee of a municipality shall hold employment without limitation of time, being subject to discharge ... only as provided in [slection 10-3-1 106.
(2) Subsection (1) does not apply to: ... (d) a deputy police chief of the municipality; ... (f) a deputy or assistant fire chief of the municipality....
Utah Code Ann. § 10-3-1105 (2007). Section 10-3-1106 provides a process under which employees categorized under section 10-3-1105(1) are entitled to appeal. See Utah Code Ann. § 10-3-1106 (2007).
. Pearson also claims that the City agreed by contract to treat him as a merit employee. That issue was not a subject of the summary judgment motions and remains pending in the trial court.
. The exceptions to this rule are when a publiс employee has a "vested contractual interest in retirement benefits," or when an employer agrees by implied or express contract to provide "additional obligations beyond the relevant statutory requirements." See Utah Pub. Emps. Ass'n v. State,
. Our Kocherhans v. Orem City,
. During Pearson's tenure, the City created a "director of public safety" position to which it elevated the police chief. While this structure was in place, Pearson served as "acting chief" under the director of public safety. Eventually, the City decided to revert to the traditionаl model, eliminating the director of public safety and reinstating the police chief. At that time, Pearson again became the "assistant police chief" and held that post until his termination.
. The parties relied on the record from the hearing before the appeals board as support for their cross-motions for partial summary judgment.
. Because we hold that Pearson's position is equivalent to a "deputy police chief," we need not reach the issue of whether Pearson was also "a deputy of a head of a municipal department." See Utah Code Ann. § 10-3-1105(2)(g) (2007).
. Indeed, Pearson asserts that the City impliedly contracted to grant him merit employment status. However, whether South Jordan contrаctually agreed to provide Pearson with more job security than was required by statute is not at issue in this appeal because the trial court did not grant summary judgment to either party on Pearson's contract claim.
. The City began compiling the list in November 2006, but did not finalize and approve it until January 2007.
. As a convenience to the reader, we note that shortly before this opinion was issued, the Utah Legislature amended section 10-3-1105 to specifically exempt "assistant" police chiefs from the merit status afforded by section 10-3-1105(1), and also added language indicating that positions that are "equivalent" to those enumerated in section 10-3-1105(2) are also exempt. See H.B. 449, 59th Leg. (Utah 2012) (enacted March 22; effective May 8, 2012).