Figure 1. Basic layout of a septic systems.
Photo from: https://www.epa.gov/septic/types-septic-systems United State Environmental Protection Agency
Septic systems play a vital role in the protection of South Carolina’s public health. Every home and business without access to public sewers must have a way to dispose of wastewater safely. Septic systems are on-site engineered systems that safely treat wastewater. Without these systems, contaminants can enter South Carolina waterways and be hazardous to humans and other organisms. Septic systems are regulated by the South Carolina Department of Health and Environmental Control (DHEC) and are essential in preventing the spread of disease to the public and protecting our public waters.
Septic systems rely on three main components to treat wastewater (Figure 1): a tank, distribution trenches, and soil. The tank helps to separate solids from the liquid portion of the wastewater. Beneficial microbes that live in the tank break down the solids in the wastewater. After the solids are broken down and or settled, the wastewater flows through pipes and into distribution trenches, where it is evenly distributed into the natural soil. The final barrier between the system and the surrounding environment is the soil, which acts both as a physical filter and as a home for other beneficial microbes. The microbes that live in the soils form a “biomat”, assisting to further breakdown contaminants found in the wastewater.
The typical installation process of a septic system follows a series of steps
Step 1-Application: An application must be completed and submitted to the local DHEC office through the e-permitting website. This includes:
- the entire application filled out and saved as a PDF,
- an official plat or deed of the property that includes dimensions and
- a completed Property Owner Permission Letter, which gives permission for DHEC personnel to access the property.
Once this paperwork is processed, the applicant is contacted through the e-permitting website to pay the $150 application fee. After the application is submitted and the application fee is paid, the application is placed at the end of the queue for site evaluations. Sites are evaluated on a first-come, first-served basis, and the timeline for evaluation is subject to weather conditions. To increase process efficiency, it is possible that the site will be evaluated earlier if it is near another site that is farther up in the queue.
Step 2- Site preparation: Listed in the application packet are specific site preparations that must be completed by the applicant before a site can be evaluated. Completing site preparation is best done before Step 1 and then checked when contacted by DHEC for site evaluation (Step 3). Specific site preparation includes:
- Clear underbrush so that the DHEC evaluator can effectively traverse and assess the site without interference from vegetation.
- The footprint of the intended building must be staked out. In addition to stakes, consider using flags and or flagging tape to help identify the building footprint.
- Place site cards (found in the application packet). A site card must be placed at the front of the property to identify it as the correct property for evaluation, and a second site card must be placed at the preferred location of the septic system. The evaluator will first evaluate the suitability of this area. If the desired area is not suitable for a system, the evaluator may evaluate other potential areas on the property. Ensure that the cards are safe from the outdoor elements; they should be sealed in plastic bags.
Step 3- Site evaluation: The site evaluation consists of an assessment of the property’s landscape, topography (slope of the landscape), and soil. The combination of these factors will determine different factors of the system, most importantly, size and layout. The texture of the soil found at the site will affect how quickly the wastewater from the system will move through the soil and deeper into the ground as well as horizontally within the soil. The topography will also impact wastewater movement, as well as how rainwater will move over the surface of the soil and then into the ground. Once the site is evaluated, a permit will be issued based on the findings. This permit will contain a sketch of the system that must be installed, including the location of where the system should be installed, as well as an area to be preserved in case a future repair is needed.
Step 4- Installation: The permit is given to the applicant’s installer of choice. The installer will then use the permit to dictate how to install the system. The installer needs to inform their local DHEC office of the scheduled installation the day before so that a final inspection can be conducted before the system is covered and connected to the building.
Step 5- Final inspection: The final inspection checks that all permit specifications have been fulfilled to ensure that the system was installed correctly and will function as intended. Some of the aspects of the system that are checked at the final installation include the depth and length of the wastewater trenches, the tank size and orientation, and the overall location of the system. These measurements are very important to make sure that the system is installed correctly and will function properly and safely.
Typical costs associated with this process include the $150 application fee, the cost of clearing the property if needed, and the cost of the installation by a licensed installer.
Options to Expedite the Process
A few options are available for applicants who would like to expedite this process. The first is to hire a Professional Soil Classifier (PSC) licensed in South Carolina to conduct a soil evaluation. This soil evaluation and the rest of the application packet are then submitted. This step follows the same steps as a typical application but allows the DHEC evaluator to conduct a faster assessment of the site. The additional cost associated with this process includes hiring the Professional Soil Classifier.
Figure 2. A Map of the Fall Line in South Carolina.
Adapted from: Snipes, D.S., W.C. Fallaw, Van Price Jr. and R.J. Cumbest, (1993). “The Pen Branch Fault: Documentation of Late Cretaceous-Tertiary Faulting in the Coastal Plain of South Carolina”, Southeastern Geology, 33, No.4, 195-218
A second option is that the applicant can hire a Professional Soil Classifier (PSC) and a Professional Engineer (PE), both licensed in South Carolina. The PSC will conduct a detailed soil evaluation and give the information to the PE, who will design an appropriate wastewater treatment system. Specific paperwork needs to be submitted to DHEC for this process to be approved. This process may also be required on sites where a DHEC evaluator finds the site unsuitable for a septic system. Additional costs associated with this option include the cost of hiring the PSC and the PE.
Another option to speed up the process is to schedule, in conjunction with DHEC, a backhoe pit to be dug at the site when the DHEC evaluator will be conducting the site evaluation. This reduces the time an evaluator needs to spend at a site and may provide more scheduling control to the applicant. Note that backhoe pits are required in areas of the state that are above the fall line that runs diagonally across South Carolina (Figure 2). Backhoe pits decrease the physical and time demands placed on the DHEC evaluators due to the nature of the soils in this area. The additional cost of this process includes the cost of the backhoe rental and operator.
The safe permitting and installation of septic systems in South Carolina is important for protecting our public health and natural resources. These systems serve an estimated 30-40% of homes in South Carolina, and their safe installation and management are important to a healthy state. Diseases spread through improperly treated wastewater (including E. coli, blue baby syndrome, and salmonella) can be easily and properly treated with a correctly installed and maintained septic system. It is the homeowner’s responsibility to install and safely manage their septic system to keep themselves and their community safe and healthy.
