7-Eleven, Inc. (“7-Eleven”) appeals a decision of the circuit court upholding a determination of the Department of Environmental Quality denying 7-Eleven full reimbursement from the Virginia Petroleum Storage Tank Fund for third-party *380damages. 7-Eleven raises four issues on appeal. For the reasons that follow, we affirm the decision of the trial court.
I. Background
A. Underlying Facts
In 1988, Hechinger, Inc. purchased a parcel of real property located in Henrico County, Virginia. The property was located near a parcel of property leased by 7-Eleven, Inc. (f/k/a) Southland Corporation. On June 11, 1990, 7-Eleven reported to the State Water Control Board (the “Board”) a leaking seal on an unleaded gasoline pump located on the property. Two days later, an environmental consultant hired by 7-Eleven found gasoline in a spring and stream located on the nearby Hechinger property.
7-Eleven subsequently hired a contractor to clean the affected areas, including those areas located on the Hechinger property. During the clean-up process, which was not concluded until September 1998,1 7-Eleven requested reimbursement from the Board for expenditures involved in correcting the petroleum release, pursuant to Code § 62.1-44.34:ll(A)(2)(a) of the statutes governing the Virginia Petroleum Storage Tank Fund (the “Fund”).2 Accordingly, the *381Board, acting through its staff, the Department of Environmental Quality (“DEQ”), reimbursed 7-Eleven for $408,838.74 of its incurred clean-up expenditures.3 The corrective action only partially abated the gasoline plume in the groundwater.
Hechinger filed a motion for judgment against 7-Eleven in the Alexandria Circuit Court on April 19, 1995. On October 15, 1996, Hechinger filed an amended motion for judgment. The amended motion for judgment contained four counts with causes of action including negligence, trespass, nuisance, and statutory liability under Code § 62.1-44.34:18(C)(4), and sought damages of $2,000,000 plus interest, costs, and attorneys’ fees.4 Shortly thereafter, 7-Eleven stipulated to statu*382tory liability under Code § 62.1-44.34:18(0(4). The case subsequently went to trial on the issue of damages. After a day and half of trial proceedings, the parties agreed to a settlement of $575,000.
B. Administrative Hearing
By letter dated May 1, 1996, 7-Eleven notified the Board of its potential claim against the Fund for third-party damages due to Hechinger, pursuant to Code § 62.1-44.34:ll(A)(2)(b). 7-Eleven notified the Board of the settlement on September 23, 1997. The DEQ held an informal fact-finding proceeding on July 12, 2000 to consider 7-Eleven’s claim for reimbursement. The DEQ also allowed both parties to submit additional evidence subsequent to the hearing. '
The evidence presented on the issue of damages included appraisals prepared by each party’s expert witnesses, depositions of each of the experts, and Henrico County tax assessment records. The evidence demonstrated that Hechinger had purchased the property at issue in 1988 for a purchase price of $903,117. However, Hechinger’s expert, Salzman Real Estate Services, Inc. (“Salzman”), opined that the preinjury fair market value of the property was $1,300,000 ($124,-820 per acre). Salzman did not offer an opinion as to the post-injury fair market value of the property. Yet, Salzman opined that Hechinger lost rental income in the amount of $710,000, and investment returns in the amount of $550,000, as a result of the environmental damage. Salzman further opined that Hechinger had to pay $283,000 in taxes, insurance, administration expenses, as well as legal fees and expert fees, that it would not have had to pay but for the contamination.
Jay B. Call, III Associates, Inc. (“Call”), an expert providing evidence on behalf of 7-Eleven, estimated the property’s preinjury fair market value as only $715,000 ($68,651 per acre). Salzberg Appraisals, Inc. (“Salzberg”), another expert for 7-*383Eleven, estimated the post-injury fair market value of the property to be $520,750 ($50,000 per acre). Salzberg based its opinion on an assumption that the contamination was no longer present and that the lower property value was merely a result of topographical problems that Salzberg described as “severe.” Henrico County tax assessment records appraised the property at a pre-injury value of $938,700 ($90,130 per acre), and a post-injury fair market value of $508,700 ($48,843 per acre). However, the County based its reduced assessment amount on the estimated cost to perform remediation on the property, which had already been largely completed, and for which the Board had already reimbursed 7-Eleven.
The evidence further established that Hechinger listed the property for sale in 1990, prior to the discovery of the contamination, asking for a price of $1,550,000. Hechinger was ultimately offered $800,000 for the property in 1996. In determining the amount 7-Eleven was entitled to for reimbursement, the hearing officer, J. Andrew Hagelin, Director of the Office of Spill Response and Remediation, stated the DEQ’s interpretation of the standard to determine “reasonable and necessary” costs for third party claims as follows: 1) the claimant’s legal liability for third party damages must be at least disputable; 2) the amount of damages claimed must be supported by the evidence; and 3) the types of damages must be eligible pursuant to the Fund’s Guidelines.
After concluding 7-Eleven’s liability was at least disputable, the hearing officer evaluated legal precedent concerning the availability of damages. The hearing officer considered “whether (i) the facts justified] permanent, temporary or both types of damages; (ii) whether an adjustment for the partial cure of the Hechinger property should be applied; and (iii) whether an adjustment for multiple causes of damages applied].” He concluded as follows:
Upon site closure, contamination remained on the Hechinger property. The Regional Office’s July 7, 2000 memorandum indicates that it is simply not possible to predict how long it will take for natural attention [sic] to return the site to background levels. [7-Eleven] provided no evidence and *384no evidence exists in the Agency’s records that indicates the remaining contamination will attentuate within a known time frame. Consequently, it is appropriate to treat the injury as permanent. That measure for permanent injury to real property pursuant to Packett v. Herbert [237 Va. 422, 377 S.E.2d 438 (1989),] is the permanent dimunition in the value of property.
To determine the permanent dimunition in the value of the property, the fair market value of the property after the injury is subtracted from the fair market value of the property before the injury.
In making this determination, the hearing officer disregarded the expert opinions of Salzman and Call as not credible, because they valued the property well above the amount Hechinger paid for it, and well above the county assessment amount. Further, they did not offer post-injury fair market valuations and offered damage estimates using formulae other than that prescribed in Packett.5 The hearing officer also disregarded the opinion of Salzberg because the post-injury evaluation offered assumed no contamination was present on the property. In addition, the hearing officer disregarded the county’s assessed post-injury value, because it reflected the estimated clean-up costs that the Board had already paid to 7-Eleven.
Based on the remaining evidence, the hearing officer found a reasonable range for the pre-injury fair market value of the property was $903,177 to $938,700, the pre-injury county assessment amount and the actual purchase price Hechinger paid for the property just two years before the pollution report. He found the 1996 offer of $800,000 to purchase the property a reasonable basis for estimating post-injury fair market value, as most of the clean-up expenses had already been incurred and it was not unreasonable to assume the potential buyer was aware of the condition of the parcel, and that the condition was reflected in the offer price. According*385ly, he awarded 7-Eleven $103,117 ($903,117-$800,000) in reimbursement for third-party claim costs, finding this amount of damages most accurately reflected the actual market value of the property.6
C. Circuit Court Appeal
7-Eleven appealed this finding to the Richmond Circuit Court arguing that the hearing officer 1) failed to consider important factors in analyzing the reasonableness of the settlement; 2) misunderstood and misapplied the law of damages; and 3) arbitrarily and capriciously rejected the opinions of certain experts. 7-Eleven further contended that the Fund’s Guidelines conflicted with Code § 62.1-44.34:ll(A)(2)(b). 7-Eleven asserted that each of these issues constituted matters of law, requiring little deference to be given to the determination of the DEQ.
Following written briefs and oral argument, the trial judge issued a letter opinion finding the decision concerning “reasonable and necessary per occurrence costs” was an area involving the special expertise of the DEQ, entitling its decision to deference and making the appropriate standard of review whether the decision was supported by substantial evidence. Finding that the decision was both supported by the evidence and not arbitrary and capricious, the trial court upheld the DEQ’s decision.
II. Analysis
A. Standard of Review
On appeal, 7-Eleven first contends that the circuit court employed an inappropriate standard of review in considering the DEQ’s determination. Specifically, 7-Eleven contends that the substantial evidence standard is inapplicable to ques*386tions of law and that judicial deference to the DEQ is inappropriate in matters outside the scope of its specialized competence and expertise. We don’t disagree with this basic statement of the law.
Judicial review of agency decisions is authorized by the [Virginia Administrative Process Act]. See Code § 9-6.14:17. Issues of law specified in the statute “fall into two categories: first, whether the agency ... acted within the scope of [its] authority, and second, whether the decision itself was supported by the evidence.” Johnston-Willis Ltd. v. Kenley, 6 Va.App. 231, 242, 369 S.E.2d 1, 7 (1988). Although many circumstances involve “mixed questions” of both “law and fact,” issues are sometimes “oversimplified” as “legal” or “factual,” a distinction that is significant to judicial review of an administrative decision. Id. at 243, 369 S.E.2d at 7. The separate standards of review determine the degree of deference, if any, to be given to an agency’s decision on appeal. See id. at 246, 369 S.E.2d at 9.
Where the issue is whether there is substantial evidence to support findings of fact, great deference is to be accorded the agency decision. Where the issue falls outside the specialized competence of the agency, such as constitutional and statutory interpretation issues, little deference is required to be accorded the agency decision. Where, however, the issue concerns an agency decision based on the proper application of its expert discretion, the reviewing court will not substitute its own independent judgment for that of the agency but rather will reverse the agency decision only if that decision was arbitrary and capricious. Id.
Holtzman Oil Corp. v. Commonwealth, 32 Va.App. 532, 538-39, 529 S.E.2d 333, 337 (2000).
Thus, where ... legal issues require a determination by the reviewing court whether an agency has, for example, accorded constitutional rights, failed to comply with statutory authority, or failed to observe required procedures, less deference is required and the reviewing courts should not *387abdicate their judicial function and merely rubber-stamp an agency determination.
Johnston-Willis, 6 Va.App. at 243, 369 S.E.2d at 7-8. However, where the “issue is a legal issue which falls within the specialized competence of the Commissioner and his [action] involves the proper application of his expert discretion, we will reverse that decision only if it was arbitrary and capricious.” Id. at 253-54, 369 S.E.2d at 13. Indeed, “in reviewing an agency decision, the courts are required to consider the experience and specialized competence of the agency and the purposes of the basic law under which the agency acted.” Id. at 246, 369 S.E.2d at 9.
“The DEQ, acting in conjunction with the Board, is the Virginia agency charged with administering] the Tank Fund.” Holtzman, 32 Va.App. at 539, 529 S.E.2d at 337 (citing Code §§ 62.1-44.34:10 through 62.1-44.34:13; Code §§ 10.1-1182 through 10.1-1187); see also Code § 62.1-44.34:11. The legislature created the Fund directing that “[disbursements from the Fund may be made” for limited purposes, including:
Reasonable and necessary per occurrence costs incurred for releases reported after December 22, 1989, by the owner or operator who is the responsible person, in taking corrective action for any release of petroleum into the environment from an underground storage tank which are in excess of the per occurrence financial responsibility requirement imposed in subsection B of § 62.1-44.34:12, up to one million dollars.
Code § 62.1-44.34:ll(A)(2)(a). After disbursing funds for clean-up costs, the statute further authorizes the Board, through the DEQ, to utilize the Fund to pay for:
Reasonable and necessary per occurrence costs incurred for releases reported after December 22,1989, by the owner or operator who is the responsible person for compensating third parties, including payment of judgments for bodily injury and property damage caused by the release of petroleum into the environment from an underground storage tank, which are in excess of the per occurrence financial *388responsibility requirement imposed by subsection B of § 62.1-44.34:12, up to one million dollars. Disbursements for third party claims shall be subordinate to disbursements for the corrective action costs in subdivision A 2 a of this section.
Code § 62.1-44.34:ll(A)(2)(b). The Board adopted regulations governing these reimbursement decisions. See 9 Va. Admin. Code § 25-590-210.
The present matter, involving the third-party reimbursement provision of Code § 62.1-44.34:11, is one of first impression in Virginia. However, as we held in Holtzman Oil Corp., “[t]he DEQ possesses the requisite experience and competence necessary to determine levels of contamination and the reimbursement due ‘owners and operators’ for the reasonable costs incurred for their environmental clean-up efforts,” pursuant to Code § 62.1-44.34:ll(A)(2)(a). Holtzman 32 Va.App. at 539, 529 S.E.2d at 337.
Although Code § 62.1-44.34:ll(A)(2)(b) involves a consideration not of the clean-up costs, but of the “reasonable and necessary per occurrence costs incurred ... by the owner ... who is the responsible person for compensating third parties, including judgments for bodily injury and property damage caused by the release of petroleum,” we find that the DEQ likewise possesses the requisite experience and competence necessary to determine appropriate reimbursement under this section.
Indeed, when the legislature amended the third-party reimbursement language in 1996, it inserted the phrase “reasonable and necessary” before each of the statute’s relevant references to “per occurrence costs.” See 1996 Va. Acts, ch. 737. In so doing, the General Assembly transferred the decision-making power in this regard to the Board and its authorized agent, the DEQ. No evidence before us discloses that it did so without first determining that the Board and its agents were fully competent to render such judgments. See Groome Transportation, Inc. v. Virginia Department of Motor Vehicles, 27 Va.App. 682, 696, 500 S.E.2d 852, 859 (1998).
*389In fact, the entire statute, by its very language, clearly addresses corrective measures, and the costs associated therewith, for remedying releases of petroleum into the environment from underground storage tanks. Thus, although the consideration here involves a determination of reasonable and necessary costs incurred by the responsible party, in compensating a third party, as opposed to clean-up costs, the costs to be considered are clearly set forth by the language of the statute, imposing no need to resort to statutory construction. They are those incurred as a result of compensating a third party for the damage caused by the environmental contamination at issue, an area which we have found falls within the specialized expertise and competence of the DEQ. See Holtzman, 32 Va.App. at 539, 529 S.E.2d at 337. As such, its enforcement and implementation of the statutes and regulations governing the Tank Fund’s reimbursement policies in this regard, are entitled to deference by a reviewing court and should only be overturned when found to be arbitrary and capricious. Holtzman, 32 Va.App. at 538-39, 529 S.E.2d at 337.
Based upon the above, we hold that the trial court properly applied the substantial evidence standard and the arbitrary and capricious standard in reviewing the hearing officer’s decision.
B. Determination of Reasonable and Necessary Costs
7-Eleven next argues that the circuit court failed to properly analyze whether the third-party settlement was reasonable and necessary pursuant to Code § 62.1-44.34:11(A)(2). 7-Eleven contends that the trial court should have considered the settlement amount in light of the pending litigation and the potential judgment and/or jury verdict range to which 7-Eleven was exposed. 7-Eleven further contends that the trial court failed to give proper consideration to the expert opinions offered as they were based upon credible valuation methodologies and would have been admissible in court. We disagree.
As stated above, and in respectful disagreement with the finding in the concurring opinion, the phrase “reasonable and *390necessary costs,” as it is utilized in Code § 62.1-44.34:11(A)(2), is clear. It provides the DEQ with the discretion to reimburse an owner for all “reasonable and necessary” costs incurred as a result of compensating a third party for environmental contamination, except those otherwise excluded by the statute.7
The phrase does not confine the DEQ’s determination to whether the costs are reasonable in the context of litigation. Thus, .because the statute provides the DEQ with the discretion to determine the reasonableness and necessity of all recoverable costs, and does not mandate any specific considerations beyond those parameters, 7-Eleven’s argument that the DEQ should have considered factors concerning the reasonableness of the settlement is without merit. Moreover, the dissent’s contention that the DEQ was required to consider the reasonableness of the settlement disregards the plain language of the statute.
In addition, contrary to 7-Eleven’s argument, neither the circuit court, nor the hearing officer, was required to give weight to the opinions offered by the various experts in this matter. Here, the issue was presented to the hearing officer as a “battle of experts.” See Tidewater Psychiatric Inst. v. City of Virginia Beach, 256 Va. 136, 141, 501 S.E.2d 761, 764 (1998). As it is the fact finder who “ ‘weighs the contradictory evidence and inferences, judges the credibility of witnesses, receives expert instructions, and draws the ultimate conclusion as to the facts,’ ” appellate courts are not free to reweigh the evidence and set aside a judgment merely because the fact finder could have drawn different inferences or conclusions or *391because parties feel that other results are more reasonable. Va. and Md. R.R. Co. v. White, 228 Va. 140, 145, 319 S.E.2d 755, 758 (1984) (quoting Bly v. Southern Ry. Co., 183 Va. 162, 175, 31 S.E.2d 564, 570 (1944)). Indeed, “the very essence of [the fact finder’s] function is to select from among conflicting inferences and conclusions that which it considers most reasonable.” Id.
■ Lastly, we find no merit in 7-Eleven’s contention that the hearing officer and the circuit court disregarded the temporary damage issue. The hearing officer specifically considered whether 7-Eleven was entitled to temporary damages in this case, and determined that the injuries suffered were permanent in nature as there was no evidence suggesting that the contamination would ever be completely abated, or at least within what time frame complete abatement was likely to occur.
Accordingly, because there is substantial credible evidence supporting the hearing officer’s determinations, and because there is no indication in the record that the hearing officer’s determinations on these issues were arbitrary and capricious, we find no error in the trial court’s decision to uphold the hearing officer’s judgment.
C. Application of Guidelines
Finally, 7-Eleven maintains that the Fund’s Guidelines, which were promulgated by the DEQ and became effective on February 12, 1998, conflict with Code § 62.1-44.34:ll(A)(2)(b) by unlawfully restricting the damages subject to reimbursement. Specifically, 7-Eleven contends that the Guidelines fail “to recognize that under Virginia’s law on tort damages” a responsible party should be “entitled to recover, if proven, all of the proximately caused damages specified in [the third-party plaintiffs] motion for judgment,” as reasonable and necessary costs. 7-Eleven argues the Guidelines produce “artificial limits,” inconsistent with a claimant’s “real exposure to liability, which is what this court should presume the legislature intended.” Once again, we disagree.
*392The plain language of Code § 62.1-44.34:ll(A)(2)(b) clearly states that the Board is to reimburse for costs determined to be “reasonable and necessary” and that such costs include judgments for bodily injury and property damage. The Guidelines designate as eligible for reimbursement valid costs incurred by the responsible party in compensating the third party for bodily injury, damage to real property, including temporary damages and permanent damages, as well as personal property damage and lost net profits. Further, § VIII of the Fund Guidelines states:
The Agency’s acquiescence to a settlement between owner and third party does not mean that the Agency will pay the full settlement amount. Settlements and final court orders will be used as baselines from which the Agency will conduct eligibility, reasonableness, and necessity reviews.
Virginia Petroleum Storage Tank Fund Third Party Disbursements Guidelines, § VIII.
The fact that the Guidelines do not designate as eligible any and all costs incurred does not conflict with the charge given to the Board and its agents by the legislature. In fact, as stated above, the statute does not entitle a claimant to a recovery for any and all costs incurred in the form of damages. Instead, the legislature limited reimbursable costs to those that the Board, in its discretion, finds reasonable and necessary, “including payments of judgments for bodily injury and property damage.” Code § 62.1-44.34:ll(A)(2)(b). The legislature did not provide for reimbursement of litigation costs and/or the various damages that might be reflected in the form of a settlement. We reiterate that litigation and related settlements can often reflect inflated and/or unnecessary costs, and even speculative damages based on the parties’ theories of what a judge or jury might award.
‘Where a statute is unambiguous, the plain meaning is to be accepted without resort to the rules of statutory interpretation.” Last v. Virginia State Bd. of Med., 14 Va.App. 906, 910, 421 S.E.2d 201, 205 (1992). “‘Courts are not permitted to rewrite statutes. This is a legislative function. The manifest *393intention of the legislature, clearly disclosed by its language, must be applied.’ ” Barr v. Town & Country Properties, Inc., 240 Va. 292, 295, 396 S.E.2d 672, 674 (1990) (quoting Anderson v. Commonwealth, 182 Va. 560, 566, 29 S.E.2d 838, 841 (1944)). Therefore, we cannot broaden the parameters of the statute at issue as 7-Eleven suggests. To do so would conflict -with the legislature’s clear intention to limit the reimbursement available and to provide the Board with discretion in determining reasonable and necessary costs.
For the foregoing reasons, we affirm the decision of the trial court, upholding the award of the Department of Environmental Quality.
Affirmed.
. Although the clean-up efforts were concluded in September of 1998, it is undisputed that evidence before the Board indicated that the property would not return to its pre-injury state for some years later, the time necessary for natural attrition to take place.
. The relevant provisions of Code § 62.1-44.34:11, governing the Virginia Petroleum Storage Tank Fund, as they read at the time of the incident, stated the following:
The Fund shall be administered by the Board consistent with the provisions of Subtitle I of the federal Solid Waste Disposal Act (P.L. 98-616, § 9001 et seq.) and any approved state underground storage tank program and in accordance with the following provisions:
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2. Disbursements from the Fund may be made only for the following purposes:
a. Reasonable and necessary per occurrence costs incurred for releases reported after December 22, 1989, by the owner or operator who is the responsible person, in taking corrective action for any release of petroleum into the environment from an underground *381storage tank which are in excess of the per occurrence financial responsibility requirement imposed in § 62.1-44.34:12, up to one million dollars.
b. Reasonable and necessary per occurrence costs incurred for releases reported after December 22, 1989, by the owner or operator who is the responsible person for compensating third parties, including payment of judgments for bodily injury and property damage caused by the release of petroleum into the environment from an underground storage tank, which are in excess of the per occurrence financial responsibility requirement imposed by § 62.1-44.34:12, up to one million dollars. Disbursements for third party claims shall be subordinate to disbursements for the corrective action costs in subdivision A 2 a of this section.
. This amount was beyond the $50,000 7-Eleven was required to maintain as evidence of financial responsibility, pursuant to Code § 62.1 — 44.34:12(B).
. Code § 62.1-44.34:18 provides as follows, in relevant part:
C. Any person discharging or causing or permitting a discharge of oil into or upon state waters, lands, or storm drain systems within the Commonwealth, discharging or causing or permitting a discharge of oil which may reasonably be expected to enter state waters, lands, or storm drain systems, or causing or permitting a substantial threat of such discharge and any operator of any facility, vehicle or vessel from which there is a discharge of oil into or upon state waters, lands, or storm drain systems within the Commonwealth, or from which there is a discharge of oil which may reasonably be expected to enter state waters, lands, or storm drain systems, or from which there is a substantial threat of such discharge, shall be liable to:
4. Any person for injury or damage to person or property, real or personal, loss of income, loss of the means of producing income, or *382loss of the use of the damaged property for recreational, commercial, industrial, agricultural or other reasonable uses, caused by such discharge.
. See Packett, 237 Va. at 426-27, 377 S.E.2d at 442-43.
. The hearing officer found that no adjustment was necessary for partial cure costs and/or the potential reduction in value of property due to the topographical problems, as he found the $800,000 offer reflected an arms-length offer made at a time when the cure of the property was nearly complete.
. For example, Code § 62.1-44.34:ll(A)(2)(b) limits reimbursement of costs in the form of judgments to those related to "bodily injury and property damage caused by the release.” Code § 62.1-44.34:11(A)(5) precludes reimbursement for costs expended for payment of interest or other finance charges on loans used for corrective action or containment, under certain circumstances. Code § 62.1-44.34:11(A)(6) and (7) preclude reimbursement for costs incurred in the form of penalties, charges or fines imposed pursuant to applicable laws, as well as costs that are reimbursed or reimbursable from other applicable state or federal programs.