ABC Disposal Systems, Inc. (ABC) owns property in Hiawatha, Iowa, which it used for truck-to-trailer transfers of solid waste. Prior to investing in the equipment to perform truck-to-trailer transfers, ABC relied on advice from the Iowa Department of Natural Resources (DNR) that truck-to-trailer transfers did not require a sanitary disposal project permit. The DNR subsequently reversed its decision and ordered ABC to obtain a permit for its Hiawatha facility. It also levied a civil penalty against ABC in the sum of $5000 for ABC’s failure to obtain a permit. On administrative appeal, the Iowa Environmental Protection Commission (Commission) affirmed the DNR’s order that ABC was required to obtain a permit but reversed the Commission’s order assessing the civil penalty. ABC sought judicial review of the Commission’s decision in district court. The district court agreed with the Commission that ABC was required to obtain a permit for its Hiawatha facility. ABC appealed the district court’s decision. Because we agree that ABC is required to obtain a permit for its Hiawatha facility, we affirm the district court.
I. Background Facts and Proceedings.
ABC operates a solid waste collection business in Hiawatha, Iowa. In 1997, ABC began considering whether transfer trailers, which Brothers Industries (Brothers) manufactured, would be a good investment for ABC. Transfer trailers have expandable' sides on the receiving end and a two-way walking floor. Brothers specially designed the transfer trailer for the direct truck-to-trailer transfer of materials such as solid waste. Using a ramp, the driver of the route-collection truck backs up into the transfer trailer and unloads its contents directly onto the trailer’s floor. ABC’s driver then hauls the transfer trailer to a landfill, where the waste is disposed. The advantage of transfer trailers is that it enables ABC to consolidate waste colleсted by two to three route-collection trucks in a single transfer trailer and transport largé loads of solid waste to less expensive out-of-state disposal sites.
In the process of deciding whether to purchase transfer trailers, Ted Carter, a representative of ABC, met with a Brothers representative. As part of the sales pitch, the Brothers representative showed Carter a copy of a letter Brothers received from the DNR’s solid waste section. The letter, which was dated November 20, 1996, stated, “a transfer station permit is not required in order for rоute-collection trucks to backup and unload into the rear of a transfer trailer with expandable side walls and a two-way walking floor.”
, In order to determine whether the above letter was legitimate and to ensure it was still the DNR’s position that trans *600 fer trailers did not require a permit, Carter contacted the author of the above letter, who 'reaffirmed his earlier position. Additionally, Carter contacted ' another DNR employee who told him the same thing.
Ultimately, Carter purchased four transfer trailers and tractors to pull the trailers. ABC used its property located in Hiawatha to transfer the solid waste from the route-collection trucks to the. transfer trailers. The Hiawatha facility had a concrete ramp, which the drivers of the route-collection trucks used to back their trucks up to the transfer trailers. Once the. route-collection truck and the transfer trailer were in position, the transfer, would take place. After the transfer was completed, ABC would haul most of the solid waste it collected to a private landfill in Milan, Illinois, where ABC received more favorable tipping rates as compared to the tipping rate it received at the local Iowa landfill. On occasion, ABC has also taken solid waste to Iowa landfills. The transfer trailers loaded with solid waste remain on the Hiawatha facility for less than twelve hours, excluding weekends or holidays.
On July 8, 1998, the DNR informed Brothers that it was reversing its prior opinion concerning the need of a permit for truck-to-trailer transfers of solid waste. The letter stated, “A transfer station permit is now required for truck-to-truck transfer of solid waste.” The letter also listed other requirements for applicants to submit in order to оbtain a permit. Over three months later, the DNR sent a similar letter to ABC informing ABC of the change in its requirements. The letter gave ABC until January 8, 1999, to comply with the requirements for obtaining a permit. ABC argued it was not a “facility” under the statute and resisted the DNR’s request to obtain a permit. From July 1999 to January 2001, there was no communication between the DNR and ABC. The DNR explains the, lapse in time was because it was in the process of reviewing 567 other cases.
On November 29, 2000, at the request of the DNR, the Attorney General’s office issued an opinion concerning the requirements for operation of solid waste transfer stations in Iowa. The opinion concluded, “solid waste transfer stations are sanitary disposal projects within the meaning of Iowa Code section 455B.301Q.8), for which permits are required pursuant to Iowa Code section 455B.305.”
On January 5, 2001, the DNR once again informed ABC that it must obtain a sanitary disposal permit for its Hiawatha facility. The DNR gave ABC a deadline of February 28, 2001, to obtain the permit. ABC continued to deny it needed a permit. At ABC’s request, on April 4, 2001, an inspector from the DNR observed and videotaped a transfer of solid waste from a route-collection truck to a transfer trailer. The purpose of the DNR inspection was to gather information regarding the process that is involved with the transfer of solid waste from the route-collection trucks to the enclosed trailers. The inspector reported ABC uses two or three transfer trailers each- day to haul approximately forty tons of solid waste to the landfill. Further, the inspector observed a small amount of solid waste that escaped during the transfer, which a worker immediately recovered and placed in the transfer trailer. The inspeсtor also observed a small amount of liquid dripping from the floor of the transfer trailer onto the concrete ramp. The liquid was leachate. Leachate is “fluid that has percolated through solid waste and which contains contaminants consisting of dissolved or suspended materials, chemicals, or microbial waste products from' the solid waste.” Iowa Code § 455B.30R9) (2001). ABC informed the *601 inspector an underground tank collects the leachate through a drain connected to the tank. The underground tank was on the property when ABC purchased the propеrty. ABC had the drain installed by a third party, who is now deceased. No person at ABC knew anything about the size of the tank or the material from which it was constructed. ABC told the inspector it emptied the tank twice á week, depending on rainfall. After emptying the tank, ABC then would spread the leachate on construction debris, which absorbed more liquid than other waste materials. ABC would then put the construction debris in the transfer trailer with the other waste. After this inspection, the DNR maintained its previous position regarding ABC’s need for a permit at the Hiawatha facility.
On July 24, 2001, the DNR issued an administrative order requiring ABC to submit, within fourteen days, all sanitary disposal project permit application documents or cease operation until ABC submits the requested documentation. The order also required ABC to pay a civil penalty of $5000. ABC appealed this order to the Commission pursuant to Iowa Code section 455B.308.
An administrative law judge from the Iowa Department of Inspections and Appeals conducted the hearing. Iowa Admin. Code r. 561-17.12(1). The administrative law judge entered her proposed decision affirming the portion of the order requiring ABC to obtain a рermit for its Hiawatha facility but reversing the portion of the order that assessed the $5000 civil penalty. The Commission upheld the administrative law judge’s proposed decision. The district court, on judicial review, affirmed the decision of the Commission. ABC appeals.
II.Issues.
ABC raises several issues on appeal. They are: (1) whether the DNR . has the statutory authority to require a sanitary disposal project permit for truck-to-trailer transfers; (2) whether ABC operates a transfer station; (3) whether the statutes governing The issuance of permits for sanitary disposal projects are unconstitutionally vague; and (4) whether the DNR is estopped from issuing an administrative order based on its past representations to ABC that no permit was required for its truck-to-trailer transfer operations.
III. Standard of Review.
In reviewing the decision of the district court, we must apply the standards set forth in Iowa Code section 17A.19(10) and determine whether our application of those standards produce the same results as reached by the district court.
Auen v. Alcoholic Beverages Div.,
IV. Did the Commission Have the Statutory Authority to Require a Sanitary Disposal Project Permit for Truck-to-Trailer Transfers?
Standard of Review. The crux of the argument made by ABC on this issue is that the Commission in the agency proceeding erroneously interpreted section 455B.301(18) by finding a “sanitary dispos *602 al project” to include transfer stations using transfer trailers. ABC’s claim is covered by one of two of the enumerated provisions contained in Iowa Code section 17A.19(10). Paragraph c provides:
Based upon an erroneous interpretation of a provision of law whose interpretation has not clearly been vested by a provision of law in the discretion of the agency. - -
Iowa Code § 17A.19(10)(e). Paragraph l provides:
Based upon an irrational, illogical, or wholly unjustifiable interpretation of a provision of law whose interpretation has clearly been vested by a provision of law in the discretion of the agency.
Id. § 17A.19(10)(l). To determine which provision is applicable to this appeal, we must determine whether the legislature clearly vested by a provision of law in the discretion of the Commission the interpretation of the term “sanitary disposal project.” If the legislature vested this matter by a provision of law in the discretion of the Commission, paragraph l apрlies; otherwise, paragraph c supplies the standard of review.
The Iowa Code created the Commission as a part of the DNR. Id. § 455A.6. By statute, the legislature has given the Commission the authority to establish policy for the DNR and adopt rules necessary to provide for the effective administration of Iowa Code chapter 455B. Id. § 455A.6(6)(a). The legislature has also given the Commission the power to establish rules for the proper administration of part I of division IV of Iowa Code chapter 455B
relating to the establishment and location of sanitary disposal projects, sanitary practices, inspection of sanitary disposal projects, collection of solid waste, disposal of solid waste, pollution controls, the issuance of permits, approved methods of private disposition of solid waste, the general operation and maintenance of sanitary disposal projects, and the implementation of this part.
Id. § 455B.304(1). The legislation requiring a permit for the operation of a sanitary disposal project is contained in part I, division IV of chapter 455B. Id. § 455B.305(1). Because the legislature has clearly vested the interpretation of the provisions of the law dealing with the permitting of a sanitary disposal project in the discretion of the Commission, we can disturb the Commission’s interpretation of the law based only upon an irrational, illogical or wholly unjustifiable interpretation of this provision of the law. Id. § 17A.19(10)(l)• Additionally, we are required to give deference to the view of the agency because the legislature vested in the discretion of the agency the permitting of a sanitary disposal project. Id. § 17A.19(ll)(c).
Analysis. Iowa Code section 455B.305 requires the director of the DNR to issue permits for the operation of a sanitary disposal project. Id. § 455B.305(1). The Iowa Code defines a sanitary disposal project as:
[a]ll facilities and appurtenances including all real and personal property connected with such facilities, which are acquired, purchased, constructed, reconstructed, equipped, improved, extended, maintained, or operated to facilitate the final disposition of solid waste without creating a significant hazard to the public health or safety, and which are approved by the executive director.
Id. § 455B.301(18). By rule, the Commission has defined a transfer station as “a fixed or mobile intermediate solid waste disposal facility for transferring loads of solid waste, with or without reduction of *603 volume, to another transportation unit.” Iowa Admin. Code r. 567-100.2.
In interpreting a statute, our goal is to determine the legislature’s intent when it enacted the statute.
State v. Tague,
“All facilities and appurtenances ... connected with such facilities ... to facilitate the final disposition of solid waste” are sanitary disposal projects. Iowa Code § 455B.301(18). “Facilities,” “appurtenances,” or “facilitate” are not defined in part 1 of division IV of chapter 455B. ABC contends the court should use the definitions of “disposal” and “facilities” contained in sections 455B.482(1) and (2) to interрret section 455B.301(18). We disagree. The definitions in sections 455B .482(1) and (2) are to be used in interpreting part 9 of division IV of chapter 455B, not part 1 of division IV where section 455B.301(18) is found. Id. § 455B.482.
The plain meaning of a facility is “something that is built, constructed, installed, or established to perform some particular function.” Webster’s Third New International Dictionary 812-13 (unabr. ed.2002). “Appurtenances” are “accessory objects used in any function.” Id. at 107. “Facilitate” means “to make easier or less difficult.” Id. at 813. A transfer station is “a fixed or mobile, intermediate solid waste disposal facility for transferring loads of solid waste, with or without reduction of volume, to another transportation unit.” Iowa Admin. Code r. 567-100.2. Under the plain language of section 455B.301(18), a transfer station is built, constructed, installed, or established to make it easier to finally dispose of solid waste. The use of transfer trailers are accessory objects used in the function to make the final disposition of solid waste easier. The Commission was correct in interpreting a sanitary disposal project under section 455B.301(18) to include transfer stations that use transfer trailers.
V. Does ABC Operate a Transfer Station?
Standard of Review.
ABC claims the Commission erred in concluding its facility in Hiawatha is a transfer station. The legislature gave the Commission the discretion to conduct the appeal hearing. Iowa Code § 455B.308. We can grant ABC relief only if the determination of fact made by the commission “is not supported by substantial evidence in the record before the court when that record is viewed as a whole.”
Id.
§ 17A.19(10)(f). The agency’s decision does not lack substantial evidence merely because the interpretation of the evidence is open to a fair difference of opinion.
Myers v. F.C.A. Servs., Inc.,
to support a pаrticular finding of fact must be judged in light of all the relevant evidence in the record cited by any party that detracts from that finding as well as all of the relevant evidence in the *604 record cited by any party that supports it....
We can disturb the agency’s application of law to fact only if the agency’s application is irrational, illogical, or wholly unjustifiable because the application of law to fact has been clearly vested by a provision of law in the discretion of the agency. Iowa Code § 17A.19(10)(m).
Analysis. The record indicates that ABC transfers most of the solid waste collected by its route-collection trucks to the transfer trailers at the Hiawatha facility. Approximately forty tons of solid waste are transferred at the ABC Hiawatha facility each day. This amounts to more than ten thousand tons of solid waste in a year. This is more solid waste than is accepted by permit at some landfills located in the State of Iowa. During the transfer process, solid waste does fall to the ground and leachate drips from the route-collection truck and the transfer trailer. Although ABC immediately picks up the solid waste and puts it in the transfer trailer, ABC allows the leachate to accumulate in an underground tank. At the time of the DNR inspection, ABC informed the inspector that it empties the leachate tank twice a week depending on rainfall. At the hearing, ABC testified that it emptied the underground tank only twice last summer. There are no records indicating whether the tank is intact or if any of the leachate is being absorbed into the soil and entering the ground water.
The legislature has declared the goal of solid waste disposal in part 1 of division IV of chapter 455B to be “[t]he protection of the health, safety, and welfare of Iowans and the protection of the environ-ment_” Iowa Code § 455B.301A(1). The statutory charge given to the Commission by the legislature when the Commission adopted the rule defining transfer station was to “reflect and accommodate as far as is reasonably possible the current and generally accepted methods and techniques for treatment, and .disposition of solid waste.Id. § 455B.304(1).
Although the record indicated that persons normally think of transfer stations as sites where route-collection trucks dump their solid waste on the ground to be recollected and transferred into othеr vehicles for shipment to another site, the evidence also indicated that transfer stations do not always dump the solid waste on the ground. One example given at the hearing was where the route-collection trucks transferred the solid waste directly to compactors, rather than on the ground. There is no statutory authority requiring route-collection trucks at a transfer station to off-load their waste onto the ground.
Substantial evidence supports the finding ABC uses the Hiawatha facility to transfer loads of solid waste from one transportation unit to another. The evidence also supports a finding ABC uses fixed and mobile components to hold the solid waste at the Hiawatha facility for a period before ABC transports solid waste to its final destination. Applying these findings of' fact to the rule defining a “transfer station,” we conclude the Commission’s application of law to fact was rationál, logical, and wholly justifiable. ABC is required to obtain a sanitary disposal permit to operate its Hiawatha facility. Iowa Code § 455B.305(1).
VI. Were the Statutes Governing the Issuance of Permits for Sanitary Disposal Projects Unconstitutionally Vague?
Standard of Review.
Iowa Code section 17A.19(10)(a) allows us to grant relief from agency action if the action is “[u]neonstitutional on its face or as applied or is based upon a provision of the law that is unconstitutional on its face or
*605
as applied.” Iowa Code § 17A.19(10)(a). Under the doctrine of separation of powers, the judiciary is required to determine the constitutionality of legislation and rules enacted by the other branches of government. Lu
se v. Wray,
Analysis.
Under the Due Process Clause, a civil statute is unconstitutionally vague “when its language does not convey a sufficiently definite warning of the proscribed conduct.”
Devault v. City of Council Bluffs,
ABC argues section 455B.301(18), which defines a “sanitary disposal project,” does not give sufficient notice to ABC that its Hiawatha facility is a sanitary disposal project subject to permitting; therefore, the statute is unconstitutionally vague. It argues every act of handling, transporting, compacting, sorting, moving, or dumping of solid waste facilitates the final disposition of solid waste. It contends the simple act of transferring solid waste from a wastebasket to a dumpster at an office building or the transfer of the solid waste from the dumpster to the rоute-collection truck facilitates the final disposition of solid waste, making the dumpster a sanitary disposal project under the statute. The' district court upheld the statute as not being unconstitutionally vague by interpreting the statute to mean the facility must substantially facilitate the final disposition of solid waste. ABC contends the district court recognized the vagueness of the statute by implicitly adding the word “substantially” to clarify the definition of a solid waste disposal project and to avoid dumpsters from being solid waste disposal projects under the statute. ABC concludes its argumеnt by contending that the district court impermissibly delegated to the DNR the power to determine when a facility is a sanitary disposal project on an ad hoc and subjective basis. The DNR argues otherwise.
It is not necessary to read the word “substantially” into the statute to cure its alleged vagueness. The statute is not vague as written. The statute defines “[a]ll facilities and appurtenances ... which are acquired, purchased, constructed, reconstructed, equipped, improved, extended, maintained, or operated to facilitate the final disposition оf solid waste ...” as sanitary disposal projects. - The *606 facility must not only “facilitate the final disposition of solid waste,” but must also be “acquired, purchased, constructed, reconstructed, equipped, improved, extended, maintained, or operated” for that purpose. A dumpster located at an office building is not located at a facility “acquired, purchased, constructed, reconstructed, equipped, improved, extended, maintained, or operated to facilitate the final disposition of solid waste.” The legislature has not given the DNR thе authority to define sanitary disposal projects on an ad hoc or subjective basis. If the facility is acquired, purchased, constructed, reconstructed, equipped, improved, extended, maintained, or operated for the purpose to facilitate the final disposition of solid waste, it is a sanitary disposal project. This definition is not so uncertain that it fails to give fair notice to the public as to which facilities are sanitary disposal projects. ABC had fair notice its Hiawatha facility was a sanitary disposal project.
VII. Is the DNR Estopрed from Issuing an Administrative Order Based on its Past Representations to ABC that no Permit was Required for its Truck-To-Trailer Transfer Operations?
Standard of Review. The argument made by ABC on this issue is whether the Commission erroneously interpreted or applied the doctrine of equitable estoppel to the DNR’s enforcement of Iowa Code section 455B.305, requiring ABC to obtain a permit for its Hiawatha facility. The principles governing our review of this issue are the same as those applied in division IV of this opinion.
The doctrine of equitable es-toppel is a common law doctrine preventing one party who has made certain representations from taking unfair advantage of another when the party making the representations changes its position to the prejudice of the party who relied upon the representations.
Ahrendsen v. Iowa Dep’t. of Human Servs.,
Analysis.
The elements of equitable estoppel are “(1) a false representation or concealment of material facts; (2) lack of knowledge of the true facts on thе part of the actor; (3) the intention that it be acted upon; and (4) reliance thereon by the party to whom made, to his prejudice and injury.”
City of Akron v. Akron-Westfield Cmty. Sch. Dist.,
ABC relies on
Nebraska-Iowa Supply Co.
to support the application of equitable estoppel in the present case. In
Nebraska-Iowa Supply Co.,
the Iowa Department of Transportation (DOT) brought an equitable action asking the court to order Nebraska-Iowa Supply Company to remove its billboards located near primary highways beсause it failed to file a timely permit application.
We have consistently held equitable estoppel will not lie against a government agency except in exceptional circumstances.
Bailiff v. Adams County Conference Bd.,
VIII. Disposition.
Having concluded (1) the DNR had the statutory authority to require a sanitary disposal project permit for truck-to-trailer transfers; (2) ABC operates a transfer station; (3) the statutes governing the issuance of sanitary disposal project permits are not unconstitutionally vague; and (4) the DNR was not estopped from issuing its administrative order, we affirm the judgment of the district court.
AFFIRMED.