The issue in this case is whether National acted contrary to law in replacing its West Raymond mill with a like-kind mill without obtaining a PTI from the OEPA. Resolution of this issue hinges on an interpretation of certain administrative rules promulgated by the Director of OEPA.
Former R.C. 3704.03(F)1 authorized the Director of OEPA to “[a]dopt, modify, and repeal rules consistent with the purposes of this chapter prohibiting the location, installation, construction, or modification of any air contaminant source * * * unless an installation permit therefor has been obtained from the director or his authorized representative.” (Emphasis added.) Am.Sub.H.B. No. 694,139 Ohio Laws, Part II, 3460, 3740. Pursuant to this statutory authority, the director promulgated Ohio Adm.Code 3745-31-02(A), which provides that:
“[N]o person shall cause, permit, or allow the installation of a new source of air pollutants * * * or cause, permit, or allow the modification of an air contaminant source * * * without first obtaining a permit to install from the director. * * * ” (Emphasis added.)
“Install” and “installation” are defined in Ohio Adm.Code 3745-31-01(1) as “to construct, erect, locate, or affix any air contaminant source or any treatment works.” “Air contaminant source” means “each separate operation or activity that results or may result in the emission of any air contaminant.” Ohio Adm.Code 3745-31-01(D). See, also, R.C. 3704.01(C). Particulate matter, such as dust, is within the definition of “air contaminant.” Ohio Adm.Code 3745-31-01(C). See, also, R.C. 3704.01(B).
Ohio Adm.Code 3745-31-01(K) defines “new source” as “any air contaminant source * * * for which an owner or operator undertakes a continuing program of installation or modification or enters into a binding contractual obligation to undertake and complete, within a reasonable time, a continuing program of installation or modification, after January 1, 197k * * *•” (Emphasis added.)
*381Ohio Adm.Code Chapter 3745-31 sets forth PTI regulations which govern “new sources” of air pollution. In brief, the rules require that a PTI be obtained for any new source of air contaminants. Ohio Adm.Code 3745-31-02(A). The applicant must submit information about the new source to the OEPA, Ohio Adm.Code 3745-31-04, and, based on this information, the OEPA has discretion whether to grant or deny the permit, Ohio Adm.Code 3745-31-05. The process of conducting a new source review by the OEPA involves a potentially complicated, costly, and time-consuming procedure. As part of the review, the OEPA determines whether the proposed new source conforms to applicable state and federal air pollution laws, and whether the new source is the best available technology. Id.
Essentially, the requirement of a PTI, with respect to a new source review, can be triggered by the “installation” or “modification” of an air contaminant source that was installed or modified after January 1, 1974. For the most part, a “modification” does not occur unless there is a physical change or deviation in the method of operation of an air contaminant which increases emissions allowable under applicable law, or results in the release of a contaminant into the air that was not previously emitted. Ohio Adm.Code 3745-31-OKJ). The precise focus in this case is not whether a “modification” has in fact occurred but, rather, whether the replacement of the Raymond mill in 1987 with a virtually identical mill constituted the “installation” of an air contaminant source, as that term is defined and set forth in relevant administrative rules.
Appellee asserts, and the court of appeals concluded, that the replacement Raymond mill was “installed,” as defined in Ohio Adm.Code 3745-31-01(1), and, therefore, the mill constituted a “new source of air pollutants” within the meaning of Ohio Adm.Code 3745-31-02(A). National and amici curiae extensively challenge the appellee’s and the court of appeals’ interpretation of Ohio Adm.Code 3745-31-02(A) and they especially take issue with the contention that the replacement of the like-kind Raymond mill amounted to the “installation” of a “new source” of air contaminants. National asserts that “installation,” as defined and used in the rules, does not include like-kind replacement of a piece of equipment which is a component of a complex manufacturing operation. National suggests that the OEPA should have focused on whether the replacement of the mill resulted in a “modification” of an air contaminant source as opposed to whether the replacement amounted to the “installation” of a new source of air contaminants.
In considering the parties’ contentions, the trial court determined that Ohio Adm.Code 3745-31-02(A) does not govern the replacement of any air contaminant source but, rather, requires a PTI only for the installation of a new source of air contaminants or the modification of an air contaminant source. The trial court *382further concluded that the term “replacement” could easily have been included in the rules but, since it was not, the doctrine of expressio unius est exclusio alterius applies. We agree.
As set forth above, “install,” as defined in the administrative rules, means to construct, erect, locate, or affix any air contaminant source. Ohio Adm.Code 3745-31-01 does not, however, provide a definition of the terms “construct,” “erect,” “locate” or “affix.” According to Black’s Law Dictionary (6 Ed.1990) 542, “erect” and “construct” are synonymous terms. “Construct” is defined as “[t]o build; put together; make ready for use * * * [and] is distinguishable from ‘maintain,’ which means to keep up, to keep from change, to preserve.” Id., Black’s at 312. Further, “construction” is defined as “ * * * [t]he creation of something new, as distinguished from the repair or improvement of something already existing. * * * ” (Emphasis added.) Id. See, also, United, States v. Narragansett Improvement Co. (D.R.I.1983), 571 F.Supp. 688, 693 (“The uniform conclusion is that ‘construction’ imports the creation of something new and original that did not exist before.”). In addition, the word “locate” means “ * * * [t]o decide upon the place or direction to be occupied by something not yet in being * * *.” (Emphasis added.) Black’s at 939.
Literally construed, the word “installation,” as defined in Ohio Adm.Code 3745-31-01(1) and used in Ohio Adm.Code 3745-3l-02(A), connotes the establishment or formation of something that has yet to be in existence. The term, however, does not explicitly or implicitly refer to the replacement of a virtually identical (like-kind) component of a complicated manufacturing scheme.
In reaching our conclusion, we are conscious of the long-accepted principle that considerable deference should be accorded to an agency’s interpretation of rules the agency is required to administer. See State ex rel. Brown v. Dayton Malleable, Inc. (1982), 1 Ohio St.3d 151, 155, 1 OBR 185, 189, 438 N.E.2d 120, 123. See, also, Jones Metal Products Co. v. Walker (1972), 29 Ohio St.2d 173, 181, 58 C.C.2d 393, 398, 281 N.E.2d 1, 8. Further, this court has stated on previous occasions that an administrative rule that is issued pursuant to statutory authority has the force of law unless it is unreasonable or conflicts with a statute covering the same subject matter. Youngstown Sheet & Tube Co. v. Bindley (1988), 38 Ohio St.3d 232, 234, 527 N.E.2d 828, 830. Here, appellee interprets the word “installation” to embrace the replacement of a like-kind part of a rather complex manufacturing process, thereby requiring National to undergo the rigors of a new-source review. The interpretation of “installation” proposed by appellee is, in our opinion, unreasonable.
It is interesting to note that following the trial court’s ruling the OEPA proposed that Ohio Adm.Code 3745-31-01(D) be amended to negate the interpretation reached by the trial court. Included in the appendix of National’s brief is a *383letter from Donald E. Waltermeyer to Mary Cavin, hearing clerk for OEPA. In that letter, Waltermeyer submitted that the OEPA should, along with the proposed revision to Ohio Adm.Code 3745-31-01(D) incorporating the phrase “piece of equipment” within that rule, consider adding the words “‘new or replacement’ prior to ‘air contaminant source’ in the definition for ‘Install.’ ” Waltermeyer noted that the language “new or replacement” would “eliminate any confusion that might exist,” and that its inclusion would “clarify and solidify Ohio EPA’s longstanding position in these situations.” (Emphasis added.)
Appellee’s interpretation of “installation” here is interesting in light of the requested revisions by the OEPA and Waltermeyer. If the definition of “installation” is as clear as appellee presently urges there would be no need for a clarification to “solidify” the OEPA’s position. Further, to allow appellee to broadly interpret a rule that the OEPA has tacitly admitted is less than all-inclusive would be tantamount to unannounced rulemaking in violation of R.C. Chapter 119. See, generally, Brost v. Ohio State Med. Bd. (1991), 62 Ohio St.3d 218, 581 N.E.2d 515. See, also, R.C. 3704.04.
Appellee further implies that a decision that National was not required to obtain a PTI as a condition to replacing the Raymond mill diminishes the OEPA’s authority to further the purposes of R.C. Chapter 3704. However, this implication lacks merit when one considers the broad discretionary powers conferred upon the OEPA by the General Assembly.
The broad range of powers given to the Director of OEPA by the General Assembly are delineated in R.C. 3704.03. In essence, the OEPA has been given authority to develop programs and implement standards for the prevention, control and abatement of air pollution consistent with the federal Clean Air Act, Section 7401 et seq., Title 42, U.S.Code. R.C. 3704.03(E); see, also, R.C. 3704.02(A)(2). In carrying out its responsibilities, the OEPA acts as a guardian of the law. More specifically, the OEPA can exercise its authority and designate a representative to inspect any facility (public or private), at any reasonable time, to ensure that the facility is in full compliance with applicable law. R.C. 3704.03(L). Along with the discretion to inspect, the authorized representative can take samples, conduct tests and examine records or reports with respect to any emission of air contaminants. Id. Also, prior to the issuance of a PTI or renewal of a PTO, the OEPA can require the applicant “to install such equipment and conduct such tests and analyses as the director finds reasonable and necessary to determine adequately the amount and content of any emissions from such sources, the ambient air quality at the proposed site and in areas that may be affected by emissions from such sources, and any violation or potential violation of Chapter 3704. of the Revised Code or the regulations or orders promulgated thereunder.” R.C. 3704.031. A person who violates any rule *384adopted by the OEPA is subject to prosecution. R.C. 3704.06(A). At the request of the OEPA, the Attorney General is required to file suit for injunctive relief, civil penalties or “any other appropriate proceeding” in a court of competent jurisdiction against any person violating or threatening to violate R.C. 3704.05. R.C. 3704.06(B). As a result, a court with jurisdiction can grant prohibitory or mandatory injunctive relief, and require the payment of a civil penalty up to $25,000 for each day of each violation. R.C. 3704.06(B) and (C).
There is no question that Ohio’s Air Pollution Control Law has some sharp teeth. The OEPA has been provided with the authority and the means to effectuate the goals of Ohio’s Air Pollution Control Law.
We are aware of and in complete agreement with the purposes of R.C. Chapter 3704, and commend the Director of OEPA for his efforts in promulgating rules to further protect and enhance the quality of air in this state. Ohio’s Air Pollution Control Law was enacted to allow the Director of OEPA to adopt rules and maintain standards for the prevention, control and abatement of air pollution consistent with the federal Act. R.C. 3704.02(A)(2). Of equal importance, R.C. Chapter 3704 was also established for the purpose of protecting and enhancing Ohio’s air resources “so as to promote the public health, welfare, and economic vitality of the people of the state.” (Emphasis added.) Former R.C. 3704.-02(A)(1). Am.Sub.S.B. No. 258, 138 Ohio Laws, Part I, 847, 849. (The current version adds “productive capacity” to this list of things to be protected.) To reflect this purpose, the General Assembly has repeatedly stated that actions required by the OEPA must not only be technically feasible but economically reasonable. See, e.g., R.C. 3704.03(1) and (R).
As is evident, the General Assembly intended to strike a balance between the prevention, control and abatement of air pollution and excessive regulation or unwarranted interruption of a business to the point where it can no longer function competitively at a local, national or even worldwide level. Obviously, the balance sought by the General Assembly can be lost if the quest for clean air is accompanied by excessive regulation. Excessive regulation can disrupt vital functions of a business, threatening the company’s very existence. Similarly, exposing a business to regulations not explicitly covered by statute or rule could have an equally detrimental impact. R.C. Chapter 3704 sets forth the role a business, as an employer, plays in society. Indeed, the goal for clean air should not, unless there is no other solution, lead to possible lost jobs or irrecoverable employment opportunities.
We also note that appellee, in concluding that the court of appeals’ decision would not have a detrimental impact on businesses in this state, states that “[b]usinesses are not going to have to cease operations simply because they choose to repair or replace a piece of equipment. Yet, they will have to plan *385ahead and submit an application for a PTI before they decide to replace an air contaminant source.” (Emphasis added.) Appellee’s comment ignores the realities in which some businesses must operate. Granted, it would inure to a company’s benefit if it could plan for all interruptions in the workplace. Realistically, however, such a situation cannot exist under all circumstances. Therefore, a balance between needed business regulation and needed business preservation must be struck.
We believe that absent a precise and reasonable directive from the General Assembly or a reasonable rule properly promulgated by the Director of OEPA on the subject, a business entity should not be forced to encounter the potential costs and delays associated with a PTI.if a component of a manufacturing process becomes inoperable and the component is replaced with a like-kind piece of equipment. Thus, we hold that a like-kind replacement of a piece of equipment that is a component of a complex manufacturing operation involving the emission of an air contaminant does not constitute “the installation of a new source of air pollutants” within the meaning of Ohio Adm.Code 3745-31-02(A).
Keeping in mind the purposes of R.C. Chapter 3704, we must strive to reach a balance between promoting and enhancing clean air and protecting and encouraging economic growth and opportunities for the people of this state. This requires that business entities not be subjected to an interminable task of dealing with excessive regulation or requirements not explicitly covered by statute or rule. Therefore, any uncertainty with regard to the interpretation of R.C. Chapter 3704 and rules promulgated thereunder should be construed in favor of the person or entity (manufacturer or otherwise) affected by the law. Here, the mere replacement of the Raymond mill with a like-kind Raymond mill did not constitute the “installation” of a new source of air pollutants as that term is used in Ohio Adm.Code 3745-31-02(A). If the General Assembly or the Director of OEPA wishes to bring “replacement” within the ambit of “installation,” they must use the proper channels.
Accordingly, the judgment of the court of appeals is reversed. The judgment of the trial court is reinstated.
Judgment reversed.
Moyer, C.J., Wright and Pfeifer, JJ., concur. A.W. Sweeney, Resnick and F.E. Sweeney, JJ., dissent.. R.C. 3704.03(F) was amended, effective December 22, 1992, Sub.H.B. No. 359, and October 29, 1993, Am.Sub.SJB. No. 153.