Onsite septic systems meet the needs of homes that lack access to municipal services. Although they present an important source of contamination to receiving waters, they are given relatively little regulatory attention. Proper maintenance and use of onsite systems is simple and inexpensive, and can substantially decrease risk of system failure. In this study, information about onsite-system management was provided on a door-to-door basis at homes throughout northwest Ohio. Residents who received the educational program learned more about onsite-septic-system management, but the educational program did not significantly change their personal management practices. More intrusive management practices appear necessary to control pollution from this source.