Septic Plan Rejected? Redesign and Resubmit in Central NY
A rejection letter is a list of what the reviewer needs to see. Most come down to soil data, separation distances or missing design details, and most can be answered.
The short answer
County health departments review septic plans against 10 NYCRR Appendix 75-A and any stricter local or watershed rules. A plan gets sent back when the soil data does not support the design, a separation distance is short, the system type does not fit the site limits, the flow is wrong, or the plan was not prepared by a licensed design professional. A redesign answers each comment with new data, a different system, or a waiver request.
Common reasons septic plans get rejected
Soil data does not match the design
Appendix 75-A.4 says a perc test is only an indicator and must agree with the soil seen in the test holes. If they conflict, more tests are required and the most restrictive result governs. A fast perc in a hole the reviewer logged as silty clay will not stand. Fix: new perc tests and a deep hole, and a design sized on the slower number.
Groundwater not established
Seasonal high groundwater has to be determined, including whether it is perched, apparent or artesian. A hole dug in August with no mottling description is a weak record. In the Skaneateles watershed, soil analyses should be done March 15 to June 30, or mottling used, and a wet season observation can be required.
Separation distances short
100 feet from the field to any well, lake, stream or wetland; 20 feet to the house; 10 feet to the line; 10 feet from any water service line; 200 feet when upgrade in the path of drainage to a well; 50 percent more well distance for wells drawing water less than 50 feet down. Distances run from the toe of fill and the edge of the reserve area. See small lot and setbacks.
Wrong system for the site
Beds proposed in clay or silty loam, mounds on slopes over 12 percent, raised systems over 15 percent, a raised system where groundwater is within 1 foot of the surface, seepage pits where trenches would work, gravity distribution on a raised system without the conditions that allow it.
Flow and tank sizing
New homes are designed at 110 gallons per day per bedroom. An expansion attic counts as a bedroom. A garbage grinder adds 250 gallons and 7 square feet of tank surface area, and requires a gas deflection baffle or similar outlet and a dual compartment tank or two tanks in series.
Fill and mound details missing
Raised system fill must be perc tested at the borrow pit and again after placement and settling. Mound sand has grain size limits and the mound hydraulic design is worked out with the health unit. Onondaga County uses a fill certification form signed with a New York license number.
Not prepared by a design professional
The State Health Department says all new residential systems must be designed by a licensed engineer or architect, and repairs that move, extend or rebuild a field, or use a raised system, mound or sand filter, need one too. Cayuga County requires new system plans from a PE or Registered Architect.
Watershed rules not addressed
Appendix 75-A.2 says stricter local and watershed standards apply. In the Skaneateles watershed, plans also go to the City of Syracuse for review and comment, and soil testing must be witnessed by the City's watershed inspector. See lakefront septic.
The specific waiver route
Appendix 75-A.11 allows deviations from the standards by a specific waiver from the State Health Commissioner or the designated full-time county health official. The state handbook says waivers are granted case by case for a hardship that makes a standard impractical, and are not meant as a routine way to approve systems that miss the standards. In the Skaneateles watershed, a waiver for a repair requires showing the alternatives were investigated and the chosen design minimizes risk to the lake, subject to the City's review. Cayuga County posts a P.E. Application for a Specific Waiver and a variance application. Onondaga County's repair form asks directly whether a waiver from any separation distance or design standard is needed.
How a redesign works with Backwell
- Send the letter and the plan. Estimate in 1 hour.
- Sort the comments. Data problems, design problems and paperwork problems get different fixes.
- Get new data where needed. Retests in the right spot and season.
- Redesign. Prepared and stamped by a New York licensed Professional Engineer (PE), with a response to each comment.
- Resubmit. Backwell files the revised plan and any waiver request.
- Build and certify. After approval, Backwell installs and the PE checks before backfill where required.
What it costs
| Item | Typical published figure | Where the number comes from |
|---|---|---|
| Perc test plus deep hole | $400 to $800 | Backwell perc test page |
| Engineered design, when required | $1,500 to $3,500 | Backwell perc test page |
| Pressure distribution system | $13,000 to $19,000 | Backwell system types page |
| Engineered mound | $22,000 to $28,000 | Backwell system types page |
| Onondaga County sewage plan review, under 1,000 gpd | $310 application; $186 redesigned project; $62 amended project | Onondaga County Local Law 11 of 2025, effective January 1, 2026 |
| Cayuga County plan review | $150 new system; $100 conventional trench repair; $150 other repair types | Cayuga County Health Department forms |
Installed ranges are typical Central New York figures Backwell publishes on its septic system types page. They are ranges, not a quote. Your number comes back in writing after we see the address and the test results.
Onondaga County also lists a $62 revised plan review. Cayuga County charges nothing to resubmit a previously approved plan that expired.
What approval does and does not mean
Cayuga County's application says plainly that acceptance by the health department does not guarantee the system will function. Approval means the plan meets the standards on paper. Building it the way it was drawn, with the right fill, level trenches and no compaction, is what makes it work.
Central New York review offices
- Onondaga County Health Department, Bureau of Public Health Engineering, John H. Mulroy Civic Center, 421 Montgomery Street, Syracuse. Sewage plan review under 1,000 gallons a day: $310.
- Cayuga County Health Department, 8 Dill Street, Auburn. New system review $150; approval can take up to 4 to 6 weeks.
- Oswego County Health Department, which approves replacements designed by a licensed engineer.
Timeline
Paperwork fixes can turn around quickly. Data fixes depend on the season: groundwater calls may need March 15 to June 30. A waiver adds review. Once approved, most installs take days.
Costs. Scope. Questions.
What it costs to answer a rejected septic plan in Central New York.
The most common reasons are perc results that do not match the soil in the deep hole, no clear seasonal high groundwater reading, short separation distances, a system type that does not fit the site limits, wrong design flow, or a plan not prepared by a licensed design professional.
The practical path is to answer the comments with new data or a revised design, or to request a specific waiver under Appendix 75-A.11 where a standard truly cannot be met. Waivers are granted case by case for hardship, not routinely.
Under Onondaga County Local Law 11 of 2025, effective January 1, 2026, a redesigned project is $186, an amended project is $62 and a revised plan review is $62. The original application for a system under 1,000 gallons a day is $310.
If the rejection was about soil data, usually yes. Appendix 75-A requires the perc to agree with the soil classification, and when they conflict the more restrictive result is used.
A written approval from the state or county health official to deviate from an Appendix 75-A standard. The state handbook says it is for hardship cases. In the Skaneateles watershed, a repair waiver also needs a showing that alternatives were investigated.
No. Cayuga County's application states that acceptance does not guarantee the system will function properly. Construction to the approved plan is what makes it work.
Designs are prepared and stamped by a New York licensed Professional Engineer (PE). Backwell coordinates the redesign, the resubmittal and the install.
Sources
- 10 NYCRR Appendix 75-A.2, Regulation by other agencies (NYS DOH)
- 10 NYCRR Appendix 75-A.3, Sewage flows (NYS DOH)
- 10 NYCRR Appendix 75-A.4, Soil and site appraisal, Table 2 separation distances (NYS DOH)
- 10 NYCRR Appendix 75-A.6, Septic tanks and enhanced treatment units (NYS DOH)
- 10 NYCRR Appendix 75-A.8, Conventional subsurface treatment systems (NYS DOH)
- 10 NYCRR Appendix 75-A.9, Alternative systems: raised systems, mounds, sand filters (NYS DOH)
- 10 NYCRR Appendix 75-A.11, Specific waivers (NYS DOH)
- NYS DOH Residential Onsite Wastewater Treatment Systems Design Handbook, 2012 edition (posted by Onondaga County Health Department)
- NYS DOH fact sheet: Need for Licensed Design Professionals, Residential Onsite Wastewater Treatment Systems
- 10 NYCRR Section 131.1, City of Syracuse Skaneateles Lake watershed rules and regulations
- Onondaga County Local Law No. 11 of 2025, Health Department fees (effective January 1, 2026)
- Onondaga County Health Department, Septic Systems and Public Sewers
- Cayuga County Health Department, Application to Install a New Septic System (rev 1/7/2025)
- Cayuga County Health Department, Septic System Installation and Inspection program
- Oswego County septic system replacement grant application
- Backwell, Septic system types and published Central New York price ranges
- Backwell, Perc test and site evaluation price table
Rules and fees change. Everything above was checked against the linked documents in October 2026. Designs are prepared and stamped by a New York licensed Professional Engineer (PE); Backwell coordinates the design, the health department submittal and the install.
