Are Late Summer Algae Blooms a Sign of Septic System Failure?

Local pond with algae bloom in late summer and fall

Have you heard of the phenomenon called an “algae bloom?” It is a yearly event that happens in bodies of water during late summer and fall in Ohio. Algae blooms, specifically harmful algal blooms (HABs), can occur when certain types of algae grow rapidly and create dense populations in water bodies. These blooms can have detrimental effects on water quality, aquatic ecosystems, and even human health.

Believe it or not, septic systems can contribute to nutrient pollution in water bodies, which in turn can contribute to the growth of algae, including harmful algal blooms (HABs). Septic systems are decentralized sewage treatment systems commonly used in areas where centralized wastewater treatment plants are not available. While they can be effective when properly maintained, they can also become a source of nutrient pollution if not managed correctly.

Several Factors Contribute to the Prevalence of Algae Blooms During Late Summer and Fall:

Warmer Temperatures:

As the temperature of water bodies increases during the summer, it provides an ideal environment for algae to grow rapidly. Warmer water temperatures enhance the metabolic activity of algae, promoting their reproduction and growth.

Nutrient Availability:

Algae require nutrients like nitrogen and phosphorus to grow. These nutrients are often introduced into water bodies through agricultural runoff, wastewater discharge, and septic run off. In late summer and fall, there might be an accumulation of these nutrients in the water, providing a conducive environment for algae growth.

Stable Conditions:

Late summer and early fall typically exhibit relatively stable weather conditions, including calm waters and consistent temperatures. These conditions can allow algae to thrive without disturbances that might hinder their growth.


Algae rely on sunlight for photosynthesis, a process through which they produce energy. Longer daylight hours during the summer and early fall provide ample sunlight for algae to carry out photosynthesis efficiently.


In some cases, water bodies might experience a phenomenon called thermal stratification, where warmer, less dense water stays near the surface while cooler, denser water stays at the bottom. This can trap nutrients near the surface, further promoting algae growth.

Are Algae Blooms Harmful?

While not all algae blooms are harmful, certain types of algae can release toxins that are harmful to aquatic life and human health. These toxins can lead to problems such as oxygen depletion in the water, fish kills, and contamination of drinking water sources.

In the state of Ohio, the government still has financial resources dedicated to water pollution control.  The Ohio EPA is offering community help to low to moderate-income homeowners to repair and replace failing home sewage treatment systems including old septic systems. To better manage and prevent algae blooms involves reducing nutrient pollution from sources like agriculture and wastewater treatment plants, as well as improving water quality monitoring and early detection of harmful blooms. You can find information on the state-provided assistance programs HERE

In addition to funding from the state of Ohio, there are also federal funding programs through the EPA. The EPA under the Clean Water State Revolving Fund (CWSRF) will help homeowners upgrade, repair, and replace existing systems.  They will help fund the construction and installation of new systems and the cost associated with the establishment of a responsible management entity (RME) which covers permits, legal fees and more.  Learn more about the program HERE.

How Can Supeck Septic Services Help:

We know that for many, maintaining an old septic system can be a challenge.  The technology for the safety of these septic systems has vastly improved.  If you are a homeowner and you are dealing with a septic tank that is over 30 years old, you may want to plan to replace the unit with a more environmentally friendly system.  Ohioans are not the only state that faces challenges due to improperly maintained or failing septic systems. Many of these failing systems are inherited from previous homeowners.

Contact us today to talk through your options and let us help you find the long-term solution for your septic system.