Help María with a gas fitter's skills: a septic backup

In July an inspector told me that my home has a septic backup. It's a safety risk for me and my elderly mother. The landlord has refused to act, and quotes of $430 are beyond us. I'm looking for a licensed gas fitter who may be able to donate a few hours or do the repair at cost. I can cover the parts, which I estimate at $35. The job should take about three hours. I'll make sure someone is home and will provide refreshments. I can share the inspector's written report on request. If you're a gas fitter and can help, or know a program that assists with this sort of repair, I'd really appreciate it. I'll keep this page updated with receipts as things happen.