(1) As provided for in RCW 36.70A.638, any city choosing the alternative density requirements in RCW 36.70A.635(4) may apply to the department for an extension of the implementation timelines established under RCW 36.70A.635(11) due to lack of infrastructure capacity.

The requirement to request an extension under RCW 36.70A.638 shall apply if a city proposes to exclude more than 25 percent of lots primarily dedicated to single-family detached units in the city and if any of those lots lack infrastructure capacity to support the middle housing densities identified in RCW 36.70A.635(1). Cities may exclude up to 25 percent of the lots in the city without the department's certification, even if those lots include lots identified as lacking infrastructure capacity. Calculation of the 25 percent must include certain lots identified in RCW 36.70A.635 (4)(b)(i) through (v). An extension certified under this section may be applied only to specific areas where a city demonstrates that water, sewer, stormwater, transportation infrastructure, including facilities and transit services, or fire protection services lack capacity to accommodate the housing density required in RCW 36.70A.635.

(2) Notice of intent to apply for an extension.

(a) The city must notify the department in writing of its intention to apply for certification for a time extension authorized by RCW 36.70A.638 at least 30 calendar days prior to submittal of the request. Prior notification allows the department to be aware in advance of a request, anticipate the need to consult with state and other agencies and, if needed, provide technical assistance to the city on required submittal materials.

(b) The city's notice of intent to apply for a certification request must include:

(i) Notice of intent to apply application form;

(ii) Identification of the ordinance(s), plan(s), documents and other materials the city intends to submit to support its request for timeline extension certification approval, as best known at the time of the submitting the notice of intent;

(iii) The geographic areas to which the time extension request will be made, as best known at the time of the submitting the notice of intent; and

(iv) A summary of the status of the application for approval of alternative approach to density requirement analysis being performed under RCW 36.70A.635(4).

(3) Public notice of intent to apply for certification of an extension.

(a) The department will publish notice in the Washington State Register that a city has notified the department of its intent to request a time extension certification.

(b) The department will post a copy of the notice of intent to apply for a time extension certification on the department website.

(c) The department will notify state agencies with expertise that a city has notified the department of its intent to apply for certification for a time extension authorized by RCW 36.70A.638.

(4) Procedures for certification of an extension. A city's application for certification for a time extension authorized by RCW 36.70A.638 must include the following items:

(a) Formal application form;

(b) A cover letter from the city requesting the time extension certification;

(c) Identification of the specific area(s) proposed for the timeline implementation extension, with clearly defined boundaries identifying which lots are and are not within the area;

(d) Identification of the specific capital facilities that lack capacity to accommodate the middle housing density required by RCW 36.70A.635(1) that serves as the basis for the time extension request to include:

(i) Documentation that the existing infrastructure for water, sewer, stormwater, transportation infrastructure, including facilities and transit services, or fire protection services, lack the capacity to accommodate minimum residential density required by RCW 36.70A.635(1).

(ii) A list of one or more improvements identified in the capital facilities element to adequately address the capacity needs for the area for which the certification of time extension request is being made. The identified improvements must include planning level cost estimates, and a timeline showing that the improvements are planned within the timeline extension period;

(e) In cases where a special district is responsible for providing the necessary infrastructure:

(i) Identification of the special district and a special district contact person.

(ii) The applicable special district provider's plan documenting the lack of capacity.

(iii) A list of projects identified by the special district associated with the timeline extension certification request;

(f) In cases where an area zoned predominantly for residential use is currently served only by on-site sewage systems, documentation that limiting development to two units per lot would still require a time extension based on lack of infrastructure capacity.

(g) If an extension of the implementation timelines is requested due to lack of water supply, the request must be based on the applicable water system plan(s) in effect and approved by the department of health.

(h) Calculations documenting that the percentages in RCW 36.70A.635 (4)(a) and (b) for lots in the city primarily dedicated to single-family detached housing units have been met during the proposed length of time for the extension request.

(i) Documentation that the city's comprehensive plan and development regulations are consistent with RCW 36.70A.635(1) and 36.70A.638 as well as with applicable growth targets, countywide planning policies, and multicounty planning policies.

(j) Any additional information that the city believes supports the request for approval of a time extension based on a lack of infrastructure capacity.

(5) Certification determination procedures.

(a) The department must approve or deny the application within 60 calendar days of receiving a city's complete request for certification of a time extension. An application is complete when the department has received all the required information identified in subsection (4) of this section including all additional information requested by the department.

(b) The department's action may, at the department's sole discretion, be extended beyond 60 calendar days.

(c) The department will issue its certification decision in the form of a written statement, including findings of fact and conclusions, and noting the date of the issuance of its decision.

(d) The department will publish its time extension certification decision on the application for extension for lack of infrastructure capacity as follows:

(i) Notify the city in writing of its determination;

(ii) Publish a notice of action in the Washington State Register;

(iii) Post a notice of its decision on the department website;

(iv) Notify state agencies with expertise with which department consulted and received substantive comments from regarding the request for approval.

(e) A time extension granted under this section remains in effect until the earliest of:

(i) The infrastructure is improved to accommodate the capacity;

(ii) The city's deadline to complete its next periodic comprehensive plan update under RCW 36.70A.130; or

(iii) The city's deadline to complete its implementation progress report to the department as required under RCW 36.70A.130(9).

(6) Subsequent extensions.

(a) A city that has received a time extension under this section may reapply for any needed extension by:

(i) Its next periodic comprehensive plan update under RCW 36.70A.130; or

(ii) If applicable, its next implementation progress report to the department under RCW 36.70A.130(9).

(b) A notice of intent to apply for an additional time extension request must be made at least six months before the expiration date of the original certification.

(c) The application for an additional time extension shall follow the process and application materials for an extension exemption as described in this section except that the city shall also submit:

(i) An updated list of infrastructure improvements and planning level cost estimates necessary to meet the infrastructure capacity required in RCW 36.70A.635(4).

(ii) Narrative on how the extension only addresses infrastructure deficiency that a city is not reasonably able to address within the first extension as required by RCW 36.70A.638(5).

(iii) The proposed length of time for the additional extension request.

(d) The department's decision on the additional certification extension request must only address infrastructure deficiency that the city has shown it was not able to reasonably address with the first extension.

(e) The department may impose the time period for which the additional extension is effective. An additional time extension should, if certified, be considered the only additional time extension that will be given. A subsequent extension of time will not exceed the length (in years) of the original time extension.

(7) In considering or granting extensions under RCW 36.70A.638, nothing affects or modifies the responsibilities of cities to plan for or provide urban governmental services as defined in RCW 36.70A.030 or affordable housing as required by RCW 36.70A.070.

(8) If the department denies the request, a city may seek agency review as a brief adjudicative proceeding under RCW 34.05.482 through 34.05.494.