Chapter 5.40 ON-SITE SEWAGE DISPOSAL SYSTEM INSTALLER CERTIFICATION PROGRAM AND INSTALLATION REQUIREMENTS This chapter is included in your selections. Sections: 5.40.010 Purpose. 5.40.020 Definitions. 5.40.030 Procedures. 5.40.040 Certificate required. 5.40.050 Duties and obligations. 5.40.060 Certification.