As Riverton City looks to take the next step toward creating its own service district area for police protection, it may trigger a bigger exodus from the taxing district set up to fund the Unified Police Department as a regional law-enforcement agency. The Salt Lake Valley Law Enforcement Service Area (SLVLESA) was formed a decade ago and includes unincorporated Salt Lake County and its various townships, along with the cities of Riverton, Herriman and Millcreek.