In a typical year, the department said it normally receives one to three calls of illegal installations. However, in the last six months, the department said it's received at least ten.
Dwayne Rogers, director for Environmental Services and Watershed Protection, said these installations end up costing thousands to repair, and they are harmful to the environment.
"They affect the water quality because that stuff runs off into the drainage ditches, which runs into the channels and into the bays," Rogers said. "Nobody wants waste to be coming into their yard or in their ditches."
Erwin Burden, Harris County chief of Engineering Architecture Services, said there are several different warning signs to look out for.
"You'll have a professional who wants to work for cash," Burden said. "They won't provide you inspections or any other work, or they won't give you a receipt for the work."
These illegal installations have left licensed companies, like A&J Septic, to fix the mistakes.
A&J Septic owner Andrew McCaffey said he's responding to more calls for poorly put together septic systems.
"It just is very unprofessional looking," McCaffey said. "They're not even buying the correct parts."
McCaffey said they're having to go back to people's property and repair the systems.
"We have to pump those tanks out, get rid of any raw sewage on the ground or anything like that, rip the tanks out, and completely start over from scratch," McCaffey said.
The county stressed the importance of looking up an individual or company's information on the Texas Commission on Environmental Quality's website. On the website, someone can see if they are licensed, along with permits, registrations or other authorizations.