Modifies provisions governing city-county library boards of trustees in St. Charles County

HB 1830 modifies Missouri law to establish a new process for merging city and county library services in specific circumstances. It allows cities and counties with equal library tax levies and a county population under 250,000 to petition for a "city-county library" board, subject to approval by both governing bodies within 30 days. The new nine-member board is appointed based on population comparisons: if the county is larger, five members are appointed by the county; if the city is larger, five members are appointed by the city mayor (or by mayors of top four cities in larger counties). The bill requires merging unspent funds from both libraries and dissolving the separate city board upon approval. This affects St. Charles County (as the example) and any other qualifying Missouri county.