Complex sentence: FSM has become synonymous with the term "septage management", where septage is the partially digested fecal solids that accumulates in septic tanks, but also may include other storage vessels, such as pits or other onsite sanitation facilities (OSSF).
Split into simpler sentences: FSM has become synonymous with the term "septage management". Septage is the partially digested fecal solids that accumulates in septic tanks, but also may include other storage vessels, such as pits or other onsite sanitation facilities (OSSF).