I was working from home today and had a knock on the door. I'm thinking, oh great, another walking salesperson trying to sell me a cleaning product... a few weeks ago one of those knocked on the door while I was showing a house. Anyway, the woman introduced herself and said she was from the EPA and that they were inspecting septic systems in our area.
They are checking to make sure there is no sewage leaking into the yard and ditch. If you have an aeration system they are checking to make sure that the motor is running.
She gave me a copy of our current septic record that shows a map of how it's laid out on the property and the date it was installed. She also gave me a nice brochure about how to maintain the system and why it's important to do so.
If you hear a knock on your door in the near future it may be her!