20250625 16445700 1.0 TRUE MD SAFE PSAP Nov2020 Archive The primary use for the PSAP Boundary is to route call/emergency requests for NG9-1-1. This layer depicts the polygon(s) and related attribute information that defines the geographic area of all PSAP boundaries within a given 9-1-1 Authority’s geographic coverage area. The PSAP Boundary layer may have one or many PSAP Boundaries contained in the layer. Each PSAP Boundary defines the geographic area of a PSAP that has primary responsibilities for an emergency request. This layer is used by the ECRF to perform a geographic query to determine the PSAP to which an emergency request is routed. An emergency request is routed using the NG9-1-1 Core Services based upon the geographic location of the request, provided by either a civic address, geographic coordinate or geodetic shapes as defined in NENA-STA-010 [2][1].