A city has clear statutory authority to extend its utility services (water and sewer) outside its boundaries, but its authority to do so is limited outside its urban growth area (UGA). With respect to a city's authority to extend water service outside its city boundaries, see RCW 35.92.17 (titled "City may extend water system outside limits"), which states:
When a city or town owns or operates a municipal waterworks system and desires to extend such utility beyond its corporate limits it may acquire, construct and maintain any addition to or extension of the system, and dispose of and distribute water to any other municipality, water-sewer district, community, or person desiring to purchase it.
See also RCW 35.92.180.
With respect to a city's authority to extend sewer service outside its city boundaries, see RCW 35.67.310, which states, in part:
Every city or town may permit connections with any of its sewers, either directly or indirectly, from property beyond its limits, upon such terms, conditions and payments as may be prescribed by ordinance, which may be required by the city or town to be evidenced by a written agreement between the city or town and the owner of the property to be served by the connecting sewer.
As noted above, that authority is, however, limited outside a city's UGA, particularly with regard to sewer service. That is because of the Growth Management Act's general prohibition in RCW 36.70A.110(4) on extending urban-type services outside UGAs:
In general, cities are the units of local government most appropriate to provide urban governmental services. In general, it is not appropriate that urban governmental services be extended to or expanded in rural areas except in those limited circumstances shown to be necessary to protect basic public health and safety and the environment and when such services are financially supportable at rural densities and do not permit urban development.
See definitions of "rural governmental services" and "urban governmental services" in a href="http://app.leg.wa.gov/RCW/default.aspx?cite=36.70A.030">RCW 36.70A.030(17) and (18); sewer service is an urban governmental service, while water service can either be rural or urban. In 1000 Friends of Washington v. Thurston County, WWGMHB No. 05-2-0002, Compliance Order, at 14, (2007), the Growth Management Hearings Board noted that "Under the GMA definitions of types of services, water service can be either an urban service or a rural service," and emphasized that "From these definitions, it is apparent that the critical factor in determining whether the water system is a rural or urban system is the intensity at which water service is provided." (Emphasis added.)
This limitation on extending sewer services outside a UGA applies even if the extension is for a school. So, for example, in this Growth Management Hearings Board decision, The Director of the State Department of Community, Trade and Economic Development v. Snohomish County, CPSGMHB Case No. 03-3-0020, Final Decision and Order (2004), the board concluded that an ordinance that permitted the expansion of urban governmental services (sewers) to schools and churches located in a rural area (outside a UGA) was in violation of RCW 36.70A.110(4).
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