The Milwaukee Metro Sewage District (MMSD) collection contains serials, advertisements, monographs, articles, research data, and photographs pertaining to the research and activities of the sewage district.

The 2-folder collection consists of facsimiles of correspondence to, from and about Romulo, news print and online articles and obituaries from various newspapers, advertisements for Munguia's print shop, programs for events honoring Munguia and family members, state proclamations, Texas-Mexico history. A second folder includes documents that highlight the Munguia Cisneros Family history of civic outreach and political activism.