Please see the links below for helpful information.
The Brazoria County Environmental Health Department is the governing department over On-site sewage Facilities for most of Brazoria County.
"The Environmental Health Department is dedicated to the protection of the citizens of Brazoria County through the impartial enforcement of applicable State and County Regulations. The department focuses on the permitting and regulation of food service establishments and on-site sewage facilities as well as enforcement of public nuisance regulations"
There are a few places in Brazoria County that are actually governed by the state (TCEQ), like Jones Creek, Liverpool, and Holiday Lakes.
Please visit their website for more information about
"Permitting, maintenance, and construction requirements for on-site sewage facilities (septic systems). Information for local governments wanting to become authorized agents of the TCEQ and run the program. Information about how to make a complaint related to these facilities"