1. Start with Darien and DuPage County as a deliberate footprint
The Census records Darien as a municipality in DuPage County, Illinois, with a 2020–2024 ACS 5-year population estimate of 21,879 and a margin of error of 50. Bosseo’s public product page says a firm can choose statewide coverage or limit the footprint to selected counties. For a firm evaluating Darien, that creates a concrete scope decision: should Darien be treated as one city within a DuPage County plan, or should the firm consider a broader Illinois footprint?
Recommended approach
Before approving coverage, list the cities and counties where the firm genuinely accepts matters. Confirm that Darien belongs in that service area, then compare a DuPage County scope with a broader option.
