Written by: Emma Copenhaver, Project Analyst at the UNC EFC

What Is a Septic System?

When you flush the toilet, take a shower, or do the dishes, water is being used to wash away waste, but where does this water go? Many municipalities offer a sanitary sewer utility that has a centralized wastewater treatment plant, but residents outside of municipal boundaries often do not have access to these services. Because treating wastewater is an important part of maintaining public and environmental health, communities lacking centralized sewer services turn to decentralized wastewater management systems instead.

The most common and the most environmentally friendly decentralized wastewater management systems are septic tanks. Septic tanks are on-site waste management systems designed to treat wastewater from one home or business.  As wastewater enters the tank, greasy waste, or scum, rises to the top, and solid waste, or sludge, sinks to the bottom as the wastewater settles. Healthy bacteria in the tank break down the scum and sludge. New wastewater entering the tank pushes settled wastewater, or effluent, through gravel and pipes into the drainfield. In the drainfield, naturally occurring bacteria in the biomat treats the effluent before it is released into the surrounding landscape.


Figure 1: A schematic of a typical septic system. Effluent is pushed into the second compartment in the tank while sludge and scum stay behind. Effluent is then pushed into pipes and gravel in the drainfield, where it is released into the landscape. Diagram by Eawag: Swiss Federal Institute of Aquatic Science


These systems are largely self-sufficient, but they do need to be maintained by the property owner, who must pay for the associated costs of maintenance. If septic systems are not regularly maintained, larger issues can arise that can cause the system to back up or release untreated wastewater into the environment, potentially causing serious public health issues. The large cost of repairing the systems once they are compromised is usually borne by property owners as well. In the worst cases, failing septic systems can cause a property to become condemned, creating significant housing and financial challenges for property owners. Because septic systems are on-site of individual properties, they are not normally supported by local governments beyond the initial permitting and construction. These authorities only have the power to step in when the system is failing, resulting in a reactive rather than proactive approach.

To avoid these issues, the Environmental Protection Agency recommends that septic tanks be inspected every 1 to 3 years, and pumped every 3 to 5 years to remove excess sludge and scum that is not broken down. Properly maintained septic tanks last 25 to 30 years on average, but newer constructed concrete systems can last 50 years or more.

In addition to regular maintenance, there are state-specific regulations in place to ensure the proper functioning of septic systems when they are constructed. North Carolina’s state septic regulations include specifics on soil type, distance from groundwater and surrounding structures, and depth of the tank, and they require permits to be distributed by local municipalities for septic installation.


Nags Head Septic Program

Nags Head is a coastal community located in Dare County, North Carolina. Nags Head offers municipal water services, but they do not have a centralized sanitary sewer system. Dare County has a sanitary sewer service, but it is not widely available. Because of this, 80% of properties in Nags Head rely on septic systems as safe ways to treat wastewater from homes and businesses.

 Beaches near Nags Head, NC. Many coastal communities in the state rely on septic systems to treat wastewater. Image by Karen Blaha via flickr


Nags Head has a comprehensive septic assistance program to offer education, provide financial resources, and increase community-driven support for septic users, showing their commitment to healthy and sustainable septic practices. While septic systems remain the responsibility of the property owner, Nags Head offers financial assistance for the maintenance and replacement of septic systems to residents of the town, including free septic inspections every year and a $150 credit on water bills for residents that pump their tanks. This credit is renewable every three years and covers almost half the cost of pumping. This level of financial assistance for septic maintenance is rare but serves as an effective incentive for residents to ensure proper septic function.

In addition to maintenance, the Town of Nags Head also offers low-interest loans up to $12,000 to fix major issues with septic tanks or replace failing septic tanks, which can reduce the risk of septic failure and potential property condemnation. Nags Head also offers several free resources on its website to septic owners, ranging from articles about how septic tanks work to information about their financial assistance program.

The Town of Nags Head has supplemented these financial programs with the Septic Health Initiative Program, a volunteer organization that provides support and resources to local septic owners. The organization provides (1) septic tank pumping assistance to incentivize good inspection and pumping practices, (2) water quality monitoring of both ground and surface waters to ensure septic systems are functioning properly, (3) education to increase awareness on how septic systems work and how to properly maintain them, and (4) decentralized wastewater management to monitor on-site wastewater management systems, protect water quality, and promote good septic practices. Additionally, this organization collects data on water quality and septic health from volunteers to create a comprehensive view of septic management in Nags Head, monitor water quality and septic health, and pinpoint areas for improvement.

Septic systems provide an effective way to treat on-site wastewater, but they need to be properly maintained to ensure public health and safety. Offering centralized assistance for the maintenance and replacement of septic systems promotes good practice and keeps major public health issues from occurring due to failing systems. Nags Head’s innovative septic assistance program provides several resources to promote transparency around good septic practices and incentivize healthy septic management. Though these proactive policies and programs take up-front time and investment from local governments, they may provide long-term benefits to septic users and the community.


Need technical assistance? The Environmental Finance Center Network is here to help!

The Environmental Finance Center Network offers free one-on-one technical assistance for small water systems. To read more about technical assistance or to express interest in our support, fill out our interest form here.