SPWorkItem.SiteId property

A globally unique identifier (GUID) specifying a Web site associated with an SPWorkItem object. This is an optional property, used for working with SPSite objects

Namespace:  Microsoft.SharePoint
Assembly:  Microsoft.SharePoint (in Microsoft.SharePoint.dll)

public Guid SiteId { get; }

Property value

Type: System.Guid
Returns a GUID that specifies a related site.

Use this property for comparing index values when performing clean-up duties that are at the scope of the site.