Septic System Inspections

Septic systems, also known as onsite wastewater systems, vary in complexity and maintenance requirements. Proper Operation and Maintenance (O&M) of these systems can lead to a longer life span of the wastewater system and avoid polluting drinking waters and our environment.

In a septic system, wastewater from sinks, toilets, showers and washing machines flows to an underground septic tank. The tank holds the solids and allows liquid to be distributed through the drainage lines into the soil, where microbes and other biological processes remove harmful bacteria. When this process isn't working, bacteria and viruses from human waste can contaminate drinking water supplies and nearby recreational water, creating a public health problem.

Most septic systems work by gravity flow (without a pump). However, septic systems that include a pump or pretreatment component must be inspected periodically by Wake County Onsite Water Protection staff. If you own one of these pump systems, you will receive a notification letter when your inspection is upcoming. Please take note of it and don’t throw away.  The property owner does not have to be home for the inspection, and the inspection will take place entirely outdoors.  Homeowners are also able to make special scheduling arrangements; for example, if they need to unlock a fence or remove pets from a yard near the septic system.  A report will be sent to the owner following the inspection.

Wake County Operation and Maintenance inspections are identified by Wake County Onsite Water Protection and are not scheduled by resident requests. If you are currently experiencing a malfunction or issue with your septic system, please check out Septic System Complaint/Report Form for additional information and to report. For more information regarding licensed septic contractors, please visit North Carolina Onsite Wastewater Contractor Inspector Certification Board website.

There are variable State-mandated inspection frequencies based on septic system type:

  • Type IIIB – This system type involves a single effluent pump and is commonly found at residential properties served by onsite septic. A Type IIIB septic system requires inspection by Wake County staff once every five years.
  • Type IV – This system type involves more than one effluent pump or systems using low-pressure pipe distribution for the drainage field. A Type IV system requires inspection by Wake County staff once every three years.
  • Type V – This system type involves advanced pretreatment components or other more complex wastewater treatment and dispersal technologies. A Type V system requires inspection by Wake County staff each year.
  • Type VI – This system type involves wastewater daily design flows greater than 3,000 gallons or systems with wastewater reuse or recycle technologies. A Type VI system requires inspection by Wake County staff twice per year.

    *Per State mandate, Types IV, V and VI require the system owner to maintain a contract with a certified operator or appropriately licensed management entity to perform maintenance items specific to the system type. This is a separate requirement from the above-detailed Wake County inspection frequencies.

To help fix any issues identified during an inspection, Wake County offers numerous programs to support to lower-income, elderly and disabled residents who might not be able to afford the repairs, offering up to $20,000 in grants, which do not have to be repaid. 

For more information please call 919-856-7400 or contact us at