What's your definition of small service? Urban/suburban/rural coverage areas?
About 15 year ago, my former volunteer EMS agency was dispatched to about 4000 calls per year; during the daytime, we had a commercial service cover our calls. Our primary crew was typically in-house, while our secondary crew could respond from home (should be within 5 minutes from the station).
My mother's volunteer EMS agency handled about 1100 calls per year; they respond from home for all calls, and have assigned duty crews every night.
Another former EMS ageny was 100% volunteer with a call volume of around 3,000, with a commercial service covering from 6am to 8pm with a single ambulance; as time went on, they migrated to a combination agency, with full time staff supplemented by volunteers. Currently, they have two crews 24/7 in house (mix of paid and volunteeer), with 3rd calls and technical rescue assignments being responding from home. Typically, volunteers got first crack at shifts (6 or 12 hour shifts), then part time / POC staff, and FT staff would get the rest.
the big question is how are you being funded... 100% donations? tax base? revenue from billing? I've always been of the believe that emergency responders should be in the station, provided the call volume supported it. Otherwise, it's very tough to justify spending 12 hours away from the family and having 0 calls. As for what that call volume is, it's up to the AHJ; If your agency runs 400 calls a year, averaging 1 call every 24 hours, is it worth it for someone to spend all day at a station? if they are paid, no issues (they are being compensated for their time), but as a volunteer, it's a much harder sell.
