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Septic Investigations

GEE is certified by the Fairfax County Health Department, Loudoun County Department of Health and other jurisdictions to research, locate, perform field investigations and percolation tests, and design septic drainfield systems in accordance with approved methods and requirements. Our field investigation for new drainfield sites are performed on areas not previously utilized for a septic field construction. Our services include:

A. Phase I Services:

  • Perform a field review to locate a suitable area based on the existing site plan and suitable topography.
  • Core drill up to five (5) investigative holes within the proposed drainfield area. The holes will be advanced to 72 inches below grades (minimum) or encountered refusal.
  • Classify the soils in accordance with the USDA System.
  • Prepare the soil profile log for each auger boring.
  • Prepare a report of our field findings and recommendations.
  • Delineate the area to be used for the new drainfield system.
  • Prepare abbreviated design for the proposed drainfield site.

B. Phase II Services:

If the preliminary field investigations revealed that the investigated site is suitable for a new septic field area, GEE will complete the phase II testings in order to obtain an approved drainfield site. This will be performed in coordination with the County Health Department. Our services for this phase include:

  • Submit request to the Health Department at least one week in advance the scheduled test date.
  • Drill five (5) test holes to a depth approved by the Health Department. The test holes will be completed using a 5-inch auger and will be performed in accordance with the county requirements.
  • Prepare the test holes in accordance with the county requirements.
  • Perform the 4-hour pre-soak test and record the rate.
  • Perform the 4-hr Percolation (Perc) Test on each of the hole, following a 24-hr presoak period
  • Record test data during the Presoak and Perc tests.
  • Coordinate with the County inspector during the performance of the field test.
  • Prepare the test results for County review and approval.

C. Septic Drainfield Design

Upon approval of the drainfield site by the Health Department, GEE will design the new septic drainfield system and prepare the Site Grading Plans for the county approval. These may include either a conventional or a pre-treatment system.