CLASS MATERIALS Residential and Commercial OSSF Septic System Installation & Repair Class Materials Class Materials is owned and operated by Jason Class. The company has been in business since 2005. We install Conventional, Low Pressure, and Aerobic septic systems with all forms of distribution. We also repair and upgrade all systems to meet TCEQ specifications. We are licensed by TCEQ as Class II Aerobic installers, maintenance providers and also perform site evaluations. From The tanks to the field line, you can be sure we will install your system with class!