Health Department

Fairfax County, Virginia

CONTACT INFORMATION: Our administration office is open during regular business hours 8 a.m. - 4:30 p.m., Monday - Friday

10777 Main Street
Fairfax, VA 22030

Gloria Addo-Ayensu, M.D., M.P.H.,
Director of Health

Onsite Sewage Disposal and Private Well Water Systems

Onsite sewage systems (OSS), commonly referred to as septic systems, are a safe and effective means of wastewater disposal when properly designed, installed and maintained. However, system failures can and do occur. An OSS failure can be caused by bad system design, improper maintenance, or simply because the system has reached the end of its life expectancy. If not functioning properly, a septic system can pose significant health risks to people, pets and the environment by discharging untreated sewage onto neighboring yards or nearby creeks or ditches.

Fairfax County Health Department's Onsite Sewage and Water Program administers state and local regulations for sewage disposal systems and private well water supplies to ensure proper construction, operation and maintenance in Fairfax County. We perform a wide variety of activities to carry out this oversight that include:

  • Reviewing installation drawings and issuing construction permits.
  • Inspecting installed systems for compliance with the regulation.
  • Provide homeowner education as needed.
  • Taking enforcement action when necessary.

Site and Soil Evaluation

The site evaluation process begins when a homeowner hires a local soil scientist to conduct preliminary soil investigations and submits an Onsite Sewage Disposal Application. Soil tests are conducted to determine if the soil conditions can accept and treat waste water. The information is submitted to the Health Department and is reviewed by one of its Environmental Health Specialists. The Environmental Health Specialist travels to the site to review the private sector Soil Scientist’s evaluation in order to determine the feasibility of constructing an onsite sewage disposal system.

Important Notice: In accordance with the Underground Utility Damage Prevention Act, all appointments that require Health Department personnel to probe, auger or otherwise "excavate" on the property will be scheduled no sooner than three working days from the date of request to allow for utility clearance.

Soil Evaluations for Shallow-Placed Systems

Soil evaluations for proposed shallow-type onsite sewage disposal systems can only be conducted during months when the average rainfall meets or exceeds a certain amount. Fairfax County's Individual Sewage Disposal Facilities code sets the amount at "the long-term monthly composite average rainfall from Washington Dulles International Airport and Ronald Reagan Washington National Airport."

More Information

For more information about alternative onsite sewage systems, conventional septic systems and private well water, please call the Onsite Sewage Disposal Systems and Private Well Water Systems Program direct line at 703-246-2201.