Onsite Sewage Professionals ← Knowledge Base How do I become a state registered installer? Is there more than one type of state installer registration? Are there requirements for maintaining my state registration? What will be needed at renewal time? How do CEU's benefit onsite professionals? When will changes in the onsite professional rules be effective? What are the changes in CEU requirements for renewal? Have there been any registration/renewal processing fee changes? How do I become licensed to inspect onsite sewage systems for real estate sales? What information is available about the number and types of onsite wastewater treatment systems (OWTS) permitted in Missouri?