A new-construction septic site evaluation determines whether a proposed building lot can support an onsite wastewater system and which system types may fit the site. In Kennesaw, the evaluator may review the planned home, expected wastewater flow, soil profile, seasonal groundwater, slope, drainage, flood conditions, wells, property boundaries, and available space. The local permitting authority uses that information to decide whether a permit can be issued and what design requirements apply.
What is a septic site evaluation?
A septic site evaluation is a field and records review completed before a new onsite wastewater system is designed or installed. The work connects the proposed building to the physical conditions below and around it. A drawing or online soil map can help with planning, but it does not replace the onsite observations and permit process required by the authority that regulates the property.
The U.S. Environmental Protection Agency says system selection depends on lot size, ground slope, soil conditions, home size or occupancy, and state or local rules. Some lots can use a conventional gravity tank and drainfield. Other lots may need a different dispersal method or added treatment. Read the EPA's septic system questions.
Start with the office that issues onsite wastewater permits for the parcel. Depending on the location, that may be a county health department, environmental health office, or another local authority. Ask which application, evaluator credentials, site plan details, fees, and inspections apply before paying for excavation or finalizing the house location.
What information should you gather before the field visit?
The evaluator needs to understand what will be built and where it may sit. Gather the parcel survey, legal description, proposed house plan, bedroom count or expected use, driveway location, water-supply plan, and any known easements. Mark proposed pools, detached buildings, patios, retaining walls, and other features that could compete with the septic area.
Look for earlier soil reports, subdivision approvals, recorded restrictions, environmental studies, and utility plans. If a previous septic permit or site evaluation exists, request the complete file rather than relying on a summary. The EPA notes that local permitting authorities may hold septic permits and record drawings with soil and installation information. Our guide to finding septic permits and records explains what to request and how to organize the results.
- A current boundary survey or reliable scaled site plan
- The proposed building footprint and number of bedrooms
- Existing or planned wells, water lines, and utility routes
- Driveways, parking, pools, decks, additions, and accessory buildings
- Streams, ponds, drainageways, wetlands, flood areas, and steep ground
- Easements, setbacks, and any area reserved for a replacement system
Do not clear, grade, fill, or compact the proposed drainfield area before the evaluator tells you what must remain undisturbed. Heavy equipment can alter the surface, hide drainage clues, and compact soil. Keeping the area intact gives the evaluator a better view of the conditions that the proposed system must use.
How does soil affect the septic system choice?
The soil below a drainfield must accept and treat septic tank effluent. An evaluator examines the soil layers in the proposed dispersal area, often through borings or excavated observation points allowed by local rules. The evaluation may document texture, structure, color, depth, rock, restrictive layers, and signs that soil remains seasonally saturated.
Soil texture affects how water moves. Very coarse material may allow water to move too quickly for adequate treatment under a basic design. Dense clay or another restrictive layer may accept water slowly. A shallow layer of rock can limit the usable depth. The important result is not a simple pass or fail label. The soil findings help determine the permitted loading rate, drainfield area, installation depth, and whether a conventional or alternative design is suitable.
Texas provides a clear example of why field results control system selection. The Texas Commission on Environmental Quality requires a site evaluation before an onsite sewage facility is built, altered, extended, or repaired. Its system-selection table compares soil classes, groundwater separation, restrictive layers, and slope with different treatment and disposal methods. Review the TCEQ system-selection guidance.
Why are groundwater, drainage, and flooding checked?
A drainfield needs usable soil between the dispersal surface and groundwater or another restrictive condition. Seasonal groundwater may sit much higher than the water level seen on a dry day. Evaluators therefore look for soil indicators, site drainage patterns, records, and other evidence required by the local program rather than treating one field observation as the whole answer.
Slope also changes how water moves across and below the ground. Depressions can collect runoff. A steep or complex slope can limit where trenches or another dispersal system will fit. Flood-prone ground may carry extra design restrictions or be unsuitable for a proposed location. Roof drains, foundation drains, driveway runoff, and stormwater channels should be planned away from the septic system so clean water does not load the treatment area.
The evaluation should identify these conditions early enough to adjust the site plan. Moving the house, driveway, or well on paper is usually easier than trying to fit a system after the building layout is fixed.
Which setbacks and site features matter?
Septic components must be separated from features that could be contaminated, damaged, or blocked. Exact distances vary by state and local rule, so do not copy a setback from another county or from a neighboring property. The evaluator and permitting office should confirm the distances that apply to the specific parcel and system type.
Common features reviewed on a site plan include:
- Property lines and recorded easements
- The house, garage, and other structures
- Private wells, public water lines, and water-supply components
- Streams, ponds, wetlands, ditches, and drainage channels
- Driveways, parking areas, retaining walls, and pools
- The septic tank, treatment components, drainfield, and replacement area
Boundary uncertainty can undermine an otherwise workable layout. Have the property corners and easements confirmed when the proposed septic area is close to a line. Our article on septic systems and property lines covers records, surveys, setbacks, and access questions that owners should resolve before construction.
Does a passing evaluation approve the final septic design?
Not necessarily. A site evaluation supplies information for permitting and design. The permitting authority may still need a complete application, scaled plan, design calculations, equipment specifications, and other documents. Some sites or system types require work by a professional with credentials defined by state or local law. Installation normally requires its own inspections before the system is covered or placed into service.
The proposed wastewater flow also matters. Residential sizing is often tied to the permitted bedroom count rather than the number of current occupants. A larger house, accessory dwelling, commercial use, or later addition may change the design flow and space needed. Keep the approved plan and permit with the property records because future changes should be checked against the system that was actually authorized.
Georgia's Department of Public Health, for example, publishes a state onsite sewage manual and lists approved soil classifiers for soil reports. Its program covers the siting, design, permitting, inspection, and troubleshooting of residential septic systems. See Georgia's official onsite sewage resources. The responsible office and required professionals differ by jurisdiction, which is why the local permit path should be confirmed first.
What can make a lot harder to approve?
A small lot is not the only challenge. Approval can become harder when the usable soil area is interrupted by rock, seasonal saturation, steep ground, flood conditions, wells, easements, utility corridors, required setbacks, or a building plan that occupies the best septic area. A lot may have plenty of total acreage but little contiguous space that meets every condition.
Do not assume that an alternative system will make every lot buildable. Different technologies still have siting limits, design rules, power needs, maintenance duties, and permit requirements. The evaluation should establish the site's constraints first. A qualified designer can then compare the systems that the local authority allows for those conditions.
What should the final evaluation package show?
Ask what written record you will receive and whether it is enough for the next permit step. A useful package identifies the parcel, proposed use, observation locations, soil findings, groundwater or restrictive conditions, slope and drainage features, relevant setbacks, available dispersal area, and any limits on system selection. It should also state who performed the work, when it was completed, and which authority will review it.
Keep the approved site plan unchanged during construction unless the permitting office accepts a revision. Builders and equipment operators should know where the primary and replacement areas are located. Keep material storage, vehicle traffic, excavation spoils, and construction staging outside those areas. If the house, driveway, well, grading, or bedroom count changes, send the revised plan for review before work reaches the septic area.
How should you plan the next step?
Contact the local onsite wastewater permitting office, confirm the required evaluator, and submit the requested property and building information. Complete the site work before locking the building footprint and major exterior features. Once the authority accepts the evaluation, move into system design, permitting, installation, inspection, and long-term record keeping in that order.
For septic service planning questions tied to a new Kennesaw property, Call (678) 719-0599. Bring the parcel address, proposed bedroom count, site plan, and any soil or permit records so the discussion starts with the facts already known.