Threshold Set Is Built-In

Piper ships with built-in ThresholdSets covering widely-used regulatory standards — such as federal MCLs or EPA regional screening levels. The isBuiltIn flag marks these platform-provided sets so compliance staff can distinguish them from custom sets their organization created. Built-in sets are typically maintained by the platform when standards are updated, whereas tenant-created sets (isBuiltIn false) are the organization's own responsibility to keep current. When assigning a ThresholdSet to a site, choosing an isBuiltIn set gives you confidence that the ThresholdValues reflect an officially published table.