The ordinance codified in this chapter, together with any amendments, shall be known as the "Seismic Hazard Area Ordinance."
(Ord. 1545 § 1 (part), 1992)
The purpose of this chapter is to regulate the use of land in seismic hazard areas in order to protect lives, property, and public infrastructure; and to comply with the Washington State Growth Management Act.
(Ord. 1545 § 1 (part), 1992)
Seismic hazard areas are areas subject to severe risk of damage as a result of earthquake-induced ground shaking, slope failure, settlement, fault rupture, or soil liquefaction.
(Ord. 1545 § 1 (part), 1992; Ord. 2071 § 25, 2003)
Seismic hazard areas are areas where the suspected risk of earthquake-induced landsliding, dynamic settlement, fault rupture, or ground deformation caused by soil liquefaction, is sufficient to require a further seismic hazard area review as set forth in SMC § 16.52.090. These potential seismic hazard areas are determined using the following criteria:
A. 
Earthquake-Induced Landslide Hazard Areas. Areas identified as potential landslide hazard areas in SMC § 16.50.050.
B. 
Liquefaction and/or Dynamic Settlement Hazard Areas. Areas identified as high and moderate liquefaction and dynamic settlement hazard areas on the Washington Department of Natural Resources, Division of Geology and Earth Resources liquefaction and dynamic settlement hazard area Geographic Map No. 44.
(Ord. 1545 § 1 (part), 1992; Ord. 2071 § 26, 2003)
All activity in seismic hazard areas shall be accompanied by the recording of a notice with the Pierce County auditor in the form set forth below:
SEISMIC HAZARD AREA NOTICE
Parcel Number:__________________
Address:_______________________
Legal Description:______________________________________________
Notice: This site lies within a Seismic Hazard Area as defined by Chapter 16.52, Sumner Municipal Code. The site was the subject of a development proposal for ___________________, Sumner application number ___ filed on__________________. Restrictions on use or alterations of the site may exist due to natural conditions of the site and resulting regulation. Review of such application has provided information on the location of a Seismic Hazard Area and any restrictions on use.
_______________________
Signature of owner(s)
(NOTARY ACKNOWLEDGEMENT)
(Ord. 1545 § 1 (part), 1992)
For all proposed short subdivisions and subdivision proposals within seismic hazard areas, the applicant shall include a note on the face of the plat as set forth below:
Notice: This site lies within a Seismic Hazard Area as defined by the Sumner Municipal Code. Restrictions on use or alterations of the site may exist due to natural conditions of the site and resulting regulation.
(Ord. 1545 § 1 (part), 1992)
For all nonexempt activities, except the construction of wood frame structures less than 5,000 square feet and all prefabricated structures less than 2,000 square feet, proposed within seismic hazard areas, a geotechnical report prepared by a professional engineer, geologist, or engineering geologist licensed by the state of Washington with expertise in geotechnical engineering shall be submitted.
A. 
The geotechnical report shall address the existing geologic, topographic and hydrologic conditions on a site, including an evaluation of the ability of the soil and structure to withstand the anticipated earthquake ground shaking and subsequent effects.
B. 
The geotechnical report shall include a discussion of the mitigation measures which can be taken to reduce seismic risks associated with the underlying surficial geology.
C. 
The geotechnical report shall include an evaluation of the effectiveness of the proposed mitigation measures.
D. 
The development proposal may be approved, approved with conditions, or denied based on the director's evaluation of the ability of the proposed mitigation measures to reduce seismic risks associated with the underlying surficial geology.
E. 
The development may be approved subject to additional review of the architectural and structural drawings by the building official for conformance with the geotechnical report and recommendations.
F. 
Should an applicant question the presence of seismic hazard areas on-site, the applicant may submit a geotechnical assessment sufficient to demonstrate to the building official's satisfaction, that the site is not located in a seismic hazard area. If the building official determines that the site is not in a seismic hazard area, the provisions of this chapter may be waived except that the requirements of SMC § 16.52.070 and § 16.52.080 may not be modified.
(Ord. 1545 § 1 (part), 1992; Ord. 2071 § 27, 2003)