These consolidated cases arise out of King County’s (County’s) designation of the Bear Creek area as an urban growth area (UGA) in the County’s growth management plan. The County also enacted an ordinance designating the property as a fully contained community (FCC). Friends of the Law (Friends) appealed both designations to the Central Puget Sound Growth Management Hearings Board (Board), which overturned the UGA, but upheld the FCC. The parties appealed to superior court, which reversed the Board on both holdings. The parties again appealed to this court. We review the Board’s decisions, without regard to the superior court rulings. Because the Board’s interpretations of the Growth Management Act (GMA)1 were reasonable and were supported by substantial evidence, we vacate the superior court’s judgment and affirm the Board’s decision.
I
This case concerns the future development of 2,500 acres of land (the Bear Creek island) situated between Redmond and Duvall in east King County. Much of the land surrounding this proposed development is rural, with the Redmond watershed abutting the proposed development to the west. Before the challenged county decisions, the property was designated as rural development. Quadrant, the owner of the property, wishes to develop the land in a comprehensive *566manner by incorporating commercial, multifamily, and single family units on the site. This cannot be done with a “rural development” designation.2
In 1994, King County designated the Bear Creek island as a UGA. Friends appealed this decision to the Central Puget Sound Growth Management Hearings Board. The Board first affirmed the County’s designation, but on reconsideration reversed King County. The Board ruled that for the development to continue, the County either needed to provide proper justification for its UGA designation or redesignate the development as a fully contained community under RCW 36.70A.350.
Eventually, the parties appealed this decision to the Washington Supreme Court. The Supreme Court remanded “for a determination of whether the County has adequately complied with the terms of the Board’s Order on Reconsideration by justifying the Bear Creek urban designation under the terms of the GMA or by redesignating the area as an FCC.”3
On remand, the Board again determined that the Bear Creek island did not meet the statutory requirements for UGA designation because the property was not “already characterized by urban growth,” and not “adjacent to lands characterized by urban growth.” But the Board also concluded that the Bear Creek island satisfied the fully contained community designation enacted by the County following the Board’s earlier remand. All three parties have challenged portions of the Board’s order.
II
When reviewing an administrative decision, this court sits in the same position as the superior court, applying the standards found in the Administrative Proce*567dure Act4 directly to the record before the agency.5 The standard of review for administrative orders is set forth in RCW 34.05.570(3). With respect to issues of law under RCW 34.05.570(3)(d), we apply a de novo standard, giving substantial weight to the Board’s interpretation of the statute it administers.6
While a reviewing court owes “deference to an agency interpretation of the law where the agency has specialized expertise in dealing with such issues,” the court is not bound by the agency’s conclusions of law.7 The burden of demonstrating that the Board erroneously interpreted or applied the law, or that the Board’s order is not supported by substantial evidence lies on the party asserting the error.8
The Growth Management Act
The legislature created the Growth Management Act to control urban sprawl and ensure that “ ‘citizens, communities, local governments, and the private sector cooperate and coordinate with one another in comprehensive land use planning.’ ”9 The GMA requires that counties adopt a comprehensive growth management plan which, among other things, designates UGAs. UGAs are regions within which urban growth is encouraged and outside of which growth can occur only if it is not urban in nature.10 The GMA’s goals include reducing sprawl, encouraging develop*568ment in areas already characterized by urban development, preserving open spaces and the environment, and encouraging availability of affordable housing.11
The GMA forbids growth that is “urban in nature” outside of the areas designated as UGAs.12 “[G]rowth that makes intensive use of land for the location of buildings, structures, and impermeable surfaces to such a degree as to be incompatible with the primary use of land for the production of food, other agricultural products, or fiber, or the extraction of mineral resources, rural uses, rural development, and natural resource lands” is not allowed in areas designated as rural.13
The GMA requires counties and cities to allocate land for urban growth based on population projections made by the Office of Financial Management.14 In addition, the GMA provides that UGAs may be located “outside of a city only if such territory already is characterized by urban growth whether or not the urban growth area includes a city, or is adjacent to territory already characterized by urban growth, or is a designated new fully contained community.”15
The Friends’ Appeal
Friends appeals the superior court’s conclusion that the Board must consider probable future development when determining the meaning of “already [is] characterized by urban growth.” Friends argues that this statutory language refers to growth already present, whereas King County and Quadrant argue that the phrase contemplates evolving development. They argue that permits already issued for future development must be considered when *569determining if an area is “already characterized by urban growth.”
King County and Quadrant argue that because there will be development on the site, either as a traditional single family subdivision or as a planned unit development, the land is characterized by urban development. They point to the fact that the 1995 Urban Planned Development permit issued for this site authorized development of the entire site with 3,500 single family homes. But this permit was issued after the County’s 1994 urban growth area designation, so it cannot retroactively justify that UGA designation.
King County and Quadrant also argue that permits issued in 1988 allow development of 2,000 single family units on the property, and that these vested permits should allow the land to be considered “characterized by urban growth.” But the legal concept of vesting in the land use context means that a land use application, under the proper conditions, “will be considered only under the land use statutes and ordinances in effect at the time of the application’s submission.”16 The concept is not readily transportable to the GMA concept of “already characterized by urban growth,” and we are not persuaded that it should be.
Finally, the County and Quadrant argue that their interpretation is “strongly supported by the state’s own directives to local government.” As support, the County cites to two guidebooks prepared by the Department of Community, Trade and Economic Development (CTED) which suggest that local governments treat vested developments as already constructed when establishing urban growth area boundaries.
When the legislature enacted the GMA, it directed the CTED to provide technical assistance to local governments regarding the act’s mandates.17 WAC 365-195-030, *570promulgated by CTED, outlines the degree of deference owed by the growth management hearings boards to these recommendations. The code states that the boards must consider planning recommendations set forth in the WAC, but that the boards are not bound by them:
(1) This chapter makes recommendations for meeting the requirements of the act. The recommendations set forth are intended as a listing of possible choices, but compliance with the requirements of the act can be achieved without using all of the suggestions made here or by adopting other approaches.
(3) The growth planning hearings boards are authorized to determine, in cases brought before them, whether comprehensive plans or development regulations are in compliance with the goals and requirements of the act. In making such determinations, the boards are required to consider the procedural criteria contained in this chapter. However, compliance with these criteria is not a prerequisite to a finding of compliance with the act.[18]
The WAC goes on to set forth criteria for locating a UGA, but does not interpret the meaning of “already character*571ized by urban growth” or “is adjacent to territory already characterized by urban growth.”19
In addition to the promulgated regulations, the CTED has also issued a series of guidebooks intended to assist cities and counties with land-use issues. These publications provide easy to understand explanations for various GMA issues.
The first such CTED publication cited by King County suggests that local governments “will probably want to treat land which is committed to a future use similarly to land already developed.”20 The second publication suggests, in a section discussing what other communities have done, that local governments should take into consideration whether
[t]he area is either already developed, firm commitments have been made to development, or the area is located adjacent to existing cities or high-intensity population and employment centers. In addition to actual urban development on the ground, extensive subdivision platting at urban densities may have already occurred.[21]
But these guidebooks do not purport to interpret the relevant statute or WAC. They are not legal authority entitled to deference by the Board or this court. Adopting the position advanced by Quadrant and King County could result in different interpretations of the phrase “characterized by urban growth” by different counties. The goals of the GMA are better served by a consistent interpretation of that act, and the expertise of the GMA hearings board for interpretation of the GMA is a far more reliable basis for achieving such consistency than are the various counties.
The Board concluded that there was no urban growth adjacent to the proposed development, nor was the Bear *572Creek area already characterized by urban growth. In so concluding, the Board decided that the term “characterized by urban growth” speaks to the built environment, and is used in the present tense. The Board thus rejected an interpretation that speaks to future land uses, even if such uses are probable. The Board also rejected the County’s interpretation of “adjacent,” explaining that although there was currently some development adjacent to the Bear Creek island, that development was not there when the County approved the UGA designation, and therefore could not be considered.
The Board’s interpretations of the GMA lie within its expertise, and we conclude that they are reasonable. We therefore adopt the Board’s interpretations as our own.
Alleged Procedural Defects by King County and Quadrant
The Administrative Procedure Act provides the exclusive means for seeking judicial review of agency action.22 A party seeking judicial review of an agency order must file and serve a petition for review within 30 days of the agency decision.23 The GMA contains a complementary provision, RCW 36.70A.300, that requires any appeal of a Board decision to be filed in superior court within 30 days.24
RCW 36.70A.300 states that a party may appeal a decision by the growth management hearings board within 30 days.25 It also explains that a party may appeal “as provided in RCW 34.05.514 or [RCW] 36.01.050.” But the statute does not explain whether failing to pay the filing fee within the 30-day limit is fatal.
Friends argues that because the County did not pay its filing fee within 30 days, the court did not have jurisdiction. *573As support, Friends cites to Lewis County v. Western Washington Growth Management Hearings Board.26 In that case, Division Two of this court interpreted the 30 day limit rigidly, and held that failing either to file or to pay the filing fee within that period results in a jurisdictional defect, and mandates dismissal.27
There is no dispute that Quadrant both filed and paid the filing fee within 30 days. Because Quadrant appealed precisely the same issue appealed by King County, we do not need to decide whether to follow Lewis County. There is no prejudice to Friends, because we must consider and decide the same issues in Quadrant’s appeal.
Friends next argues that Quadrant failed to serve the Coalition for Public Trust (CPT), and that Quadrant’s petition should be dismissed.
We first note that in early proceedings before the Board on the Supreme Court remand, Friends’ attorney David Bricklin signed all briefs as “Attorney for Friends of the Law and Coalition for Public Trust.” But beginning with Friends’ response to Quadrant’s motion to dismiss, Friends’ attorney began omitting any reference to CPT. In his declaration accompanying his response to Quadrant’s motion to dismiss, he stated that he was “attorney for Friends of the Law,” and did not mention CPT.
Although Bricklin served as both Friends’ and CPT’s attorney, he did not notify the other parties or the Board that he had withdrawn as CPT’s counsel. When Quadrant filed and served its appeal on Friends’ attorney, CPT received that notice.28
*574Quadrant/King County Appeal
The legislature has established a procedure allowing urban development on lands otherwise failing to satisfy the UGA locational requirements, provided that the requirements in RCW 36.70A.350 are satisfied. These developments, known as fully contained communities, can have urban densities and services even though the land is not already characterized by urban growth, and is not adjacent to lands characterized by urban growth. The statute sets forth specific requirements that the development must meet, including that the development must be fully contained, and not overflow into surrounding rural areas.29
Quadrant and King County appeal the superior court’s ruling that the County failed to consider “whether the proposed FCC could be fully contained in fact.” The court remanded the issue to the Board to determine whether the FCC designation complies with the general GMA goal of protecting surrounding rural land from urban development.
This issue hinges on what weight the planning goals section of the GMA, found in RCW 36.70A.020, should be given in relation to other, more specific provisions. RCW 36.70A.020 provides general guidelines and goals to “guide the development and adoption of comprehensive plans and development regulations.” Among the general goals listed by the statute are reducing sprawl and encouraging urban growth where services are easy to provide or already *575exist.30 But there is nothing in the general goals section requiring that an FCC be “fully-contained in fact.” The specific requirements governing the designation of a fully contained community are found in RCW 36.70A.350. When there is a conflict between the general goals found in RCW 36.70A.020 and the specific requirements for FCCs found in RCW 36.70A.350, the specific requirements control. Because the County clearly satisfied the specific requirements set forth in RCW 36.70A.350, we vacate the superior court’s order of remand and reinstate the Board’s decision.
To designate a new FCC, the County must meet specific criteria found in RCW 36.70A.350.31 Nine specific criteria *576must be satisfied, including the requirement that the development must be “contained”:
(g) Development regulations are established to ensure urban growth will not occur in adjacent nonurban areas.[32]
To ensure that a prospective FCC is contained, the County has enacted several ordinances.33 For example, properties adjacent to the FCC cannot tie into the sewer service from the FCC.34
King County defines an FCC as “a site specific development project consisting of conceptual site plan(s), development standards, processing and other elements, and which is consistent with the criteria provided in RCW 36.70A.350.”35 The King County Code (KCC) states that the purpose of FCCs “is to provide a means to designate a limited number of areas which are uniquely appropriate for conversion to urban development on a large scale basis.”36
To protect the character of the surrounding rural land, the County’s FCC code provision requires that “surrounding properties are classified with rural residential zoning consistent with community plan and comprehensive plan policies in order to restrict future urban development in the area solely to the FCC site.”37 Chapter 21A.39 KCC also requires that in addition to satisfying the FCC permit *577requirements found in KCC 21A.39.200,38 the FCC must also satisfy the permit requirements for Urban Planned Developments.
The KCC includes and expands upon the requirements found in RCW 36.70A.350. First, the KCC requires buffers to reduce impact on adjacent lands:
Buffers are provided between the FCC and adjacent urban and low-density residential development. Buffers located on the perimeter boundaries of the FCC delineated boundaries, consisting of either landscaped areas with native vegetation or natural areas, shall be provided and maintained to reduce impacts on adjacent lands.[39]
Second, the KCC explains with specificity what regulations the County must establish to ensure that urban growth will not spill over into adjacent lands:
Development regulations are established to ensure urban growth will not occur in adjacent nonurban areas. Such regulations shall include but are not limited to rural zoning of adjacent rural areas, urban planned development permit conditions requiring sizing of FCC water and sewer systems so as to ensure urban growth will not occur in adjacent nonurban areas; and/or urban planned development permit conditions prohibiting connection by property owners in the adjacent rural area (excepting public school sites) to new FCC sewer and water mains or lines.[40]
This nonexhaustive list sets forth the minimum standards that must be met in order to gain approval of an FCC.
In contrast, the superior court’s conclusion that the general goals of the GMA found in RCW 36.70A.020 must *578specifically be satisfied, and that these generalized goals create a requirement that the FCC be contained in fact, is not supported by the language of the RCW. The RCW explains that the goals “guide the development and adoption of comprehensive plans and development regulations [and] .... are not listed in order of priority and shall be used exclusively for the purpose of guiding the development of comprehensive plans and development regulations.”41
The Board concluded that “[t]he [B]ear [C]reek FCCs provide substantial benefits and achieve Growth Management Act goals which cannot be duplicated through the UGAs associated with cities in this part of the County.” Friends has failed to establish that the Board’s decision was erroneous.
We conclude that the. first two goals listed in RCW 36.70A.020 are general requirements which do not supersede the more stringent, specific requirements found in RCW 36.70A.350. Because King County satisfied the stringent requirements in RCW 36.70A.350, we affirm the Board’s decision.
We reverse the superior court and affirm the Board’s conclusion that Bear Creek does not meet the requirements for inclusion in King County’s UGA, and the Board’s affirmance of the County’s designation of Bear Creek as an FCC.
Becker, C.J., concurs.
Ch. 36.70A RCW.
See RCW 36.70A.030(15) (defining “rural development” as development outside the UGA).
King County v. Cent. Puget Sound Growth Mgmt. Hearings Bd., 138 Wn.2d 161, 186, 979 P.2d 374 (1999).
Ch. 34.05 RCW.
Montlake Cmty. Club v. Cent. Puget Sound Growth Mgmt. Hearings Bd., 110 Wn. App. 731, 734, 43 P.3d 57 (2002).
King County v. Cent. Puget Sound Growth Mgmt. Hearings Bd., 142 Wn.2d 543, 553, 14 P.3d 133 (2000).
City of Redmond v. Cent. Puget Sound Growth Mgmt. Hearings Bd., 136 Wn.2d 38, 46, 959 P.2d 1091 (1998).
RCW 34.05.570(1)(a); Thurston County v. Cooper Point Ass’n, 108 Wn. App. 429, 436, 31 P.3d 28 (2001), aff’d, 148 Wn.2d 1, 57 P.3d 1156 (2002).
King County, 138 Wn.2d at 166-67 (quoting RCW 36.70A.010).
RCW 36.70A.11(1).
See RCW 36.70A.020.
RCW 36.70A.110(1).
RCW 36.70A.030(17).
RCW 36.70A.110(2).
RCW 36.70A.110(1).
Noble Manor Co. v. Pierce County, 133 Wn.2d 269, 275, 943 P.2d 1378 (1997).
The relevant portion of the GMA provides that:
(1) The department shall establish a program of technical and financial assistance and incentives to counties and cities to encourage and facilitate the *570adoption and implementation of comprehensive plans and development regulations throughout the state.
(4) The department shall establish a program of technical assistance:
(a) Utilizing department staff, the staff of other state agencies, and the technical resources of counties and cities to help in the development of comprehensive plans required under this chapter. The technical assistance may include, but not be limited to, model land use ordinances, regional education and training programs, and information for local and regional inventories; and
(b) Adopting by rule procedural criteria to assist counties and cities in adopting comprehensive plans and development regulations that meet the goals and requirements of this chapter. These criteria shall reflect regional and local variations and the diversity that exists among different counties and cities that plan under this chapter.
RCW 36.70A.190.
WAC 365-195-030.
WAC 365-195-340.
Susan C. Enger, Department of Community Development Growth Management Division, Issues in Designating Urban Growth Areas, Part I, at 5 (1992).
Susan C. Enger, Department of Community Development Growth Management Division, The Art and Science of Designating Urban Growth Areas, Some Suggestions for Criteria and Densities, Part II, at 4 (1992).
RCW 34.05.510.
RCW 34.05.542(3).
RCW 36.70A.300(5).
“Any party aggrieved by a final decision of the hearings board may appeal the decision to superior court as provided in RCW 34.05.514 or 36.01.050 within thirty days of the final order of the board.” RCW 36.70A.300(5).
113 Wn. App. 142, 53 P.3d 44 (2002).
Lewis County, 113 Wn. App. at 154.
We also note that there is no evidence that CPT was a party to the proceedings. The Board order on Supreme Court remand does not list it on the service list. None of Friends’ briefs or motions were sent to CPT after its prehearing brief. There is no indication that CPT was a party, and therefore needed to be served.
RCW 36.70A.350. The relevant portion provides:
(1) A new fully contained community may be approved in a county planning under this chapter if criteria including but not limited to the following are met:
(g) Development regulations are established to ensure urban growth will not occur in adjacent nonurban areas;
(h) Provision is made to mitigate impacts on designated agricultural lands, forest lands, and mineral resource lands.
RCW 36.70A.350(l)(g)-(h).
The relevant portion of the statute provides:
The following goals are adopted to guide the development and adoption of comprehensive plans and development regulations of those counties and cities that are required or choose to plan under RCW 36.70A.040. The following goals are not listed in order of priority and shall be used exclusively for the purpose of guiding the development of comprehensive plans and development regulations:
(1) Urban growth. Encourage development in urban areas where adequate public facilities and services exist or can be provided in an efficient manner.
(2) Reduce sprawl. Reduce the inappropriate conversion of undeveloped land into sprawling, low-density development.
RCW 36.70A.020(l)-(2).
RCW 36.70A.350 provides:
A county .. . may establish a process as part of its urban growth areas . . . for reviewing proposals to authorize new fully contained communities located outside of the initially designated urban growth areas.
(1) A new fully contained community may be approved ... if criteria including but not limited to the following are met:
(a) New infrastructure is provided for and impact fees are established consistent with the requirements of RCW 82.02.050;
(b) Transit-oriented site planning and traffic demand management programs are implemented;
(c) Buffers are provided between the new fully contained communities and adjacent urban development;
(d) A mix of uses is provided to offer jobs, housing, and services to the residents of the new community;
(e) Affordable housing is provided within the new community for a broad range of income levels;
(f) Environmental protection has been addressed and provided for;
(g) Development regulations are established to ensure urban growth will not occur in adjacent nonurban areas;
*576(h) Provision is made to mitigate impacts on designated agricultural lands, forest lands, and mineral resource lands;
(i) The plan for the new fully contained community is consistent with the development regulations established for the protection of critical areas by the county pursuant to RCW 36.70A.170.
RCW 36.70A.350(l)(g).
See King County Code (KCC) 21A.08.030-.100, KCC 13.24.132, KCC 13.24.134 (requiring sewer lines crossing rural lands to be tightlined to prevent rural properties from hooking up to the lines); KCC 21A.39.200(B)(7) (requiring appropriate containment conditions to be established for FCCs, including utility sizing and connection restrictions).
KCC 13.24.132.
KCC 21A.06.533.
KCC 21A.38.110(A).
KCC 21A.38.110(B)(2).
KCC 21A.39.200(B) explains:
In order to be approved, a proposed FCC permit shall comply with the provisions relating to urban planned development permits in King County Code 21A.39.020B and C and 21A.39.030 through 21A.39.130, except that a proposed FCC shall comply with the following additional standards ....
KCC 21A.39.200(B)(3) (emphasis added) (emphasized portion not found in RCW, added by King County).
KCC 21A.39.200(B)(7) (emphasis added) (emphasized portion not found in RCW, added by King County).
RCW 36.70A.020 (emphasis added).