Why Do My Aerobic Septic Spray Heads Run Continuously During Heavy Rain?

Aerobic Septic Spray Heads Running in Rain: What Homeowners Should Know.

We often get a call from a homeowner who notices their spray heads running a lot during heavy rain and immediately assumes something must be wrong with the septic system. Your assumption is correct.

Let’s talk about why this happens.

“Yes… it’s supposed to do that.” Sometimes your septic system sprays during the rain. It’s not confused — it’s just doing its job.

Rain and Your Aerobic Septic System

Is you aerobic septic spray heads running in rain?

Aerobic septic systems treat wastewater and then pump the treated water through spray heads across the spray field. When we experience extended rainfall, several things can happen that affect how the system behaves.

For one, rain often means more water entering the system. Laundry, showers, dishwashing, and general indoor activity tend to increase when people are spending more time inside.

That extra water eventually makes its way to the septic system.

The system responds by pumping treated water out to the spray heads more frequently.

Your Spray Timer May Be Cycling On Overide

If your system is on a timer, it may pump at odd hours during heavy rain. The timer controls when the pump runs and distributes treated water through the spray heads, typically between midnight and 5 AM. During periods of heavy water use or increased tank levels, those cycles may occur more frequently.

Seeing the spray heads operate more often during wet weather means there's an issue that needs to be addressed..

Is Your Aerobic Septic Spary Heads Running in Rain?

While rain can cause increased spray activity, there are a few signs that may indicate something else is going on. Heavy rain can allow debris such as grass, leaves, and dirt to enter the system, which can cause solids to move through the system before they are properly treated.

You may want the system inspected if:

• the spray heads run constantly for long periods• the system alarm activates• spray patterns look weak or uneven• water is standing around the spray heads

These could indicate issues with the pump, timer, floats, or filters or the spray head itself.

A System Doing Its Job

Most of the time, when spray heads run during heavy rain, it may indicate that rainwater is entering the tank, which is not ideal. In some cases, risers may need to be installed, sealant may be missing around lids, the yard may need to be graded away from the tanks, or downspouts may need to be redirected away from the system.

Coleman Aerobic Septic Serving homeowners throughout Granbury, Hood County, Somervell County, and Erath County for more than 23 years.

Septic work isn’t glamorous — but keeping your system running properly is what we do best.