Yes. Under Ohio law, county commissioners can order connection when a sewer project addresses a health problem and a home's foundation sits within 200 feet of the sewer right-of-way; owners then have 90 days. Sewer districts can carry their own connection rules.
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Two layers decide it. The state layer is Ohio Revised Code 6117.51: when the board of health determines that a sewer project exists to cure an existing health problem, the county commissioners may direct nearby structures to tie in, with an exemption for foundations farther than 200 feet from the right-of-way and some carve-outs for agriculture. Owners get 90 days, and continued refusal is treated as a fresh violation every day. Ohio EPA also advises that a health district may require a connection even from a septic system that is functioning. The local layer is the sewer utility. In Delaware County, the Regional Sewer District's own rules forbid keeping a household system in service where its sewer is accessible, again with a 90-day window inside 200 feet, while its fee schedule offers existing septic homes a lower capacity fee that can be certified to the tax bill. Franklin County's recent township sewer projects have set hard connection deadlines. The best time to ask questions is at a project's public meetings, before assessments and dates are final.