Septic Engineer in Granby, NY

Septic design in Granby: the short answer

Granby lies on the west side of the Oswego River across from Fulton. Outside the city sewer, homes treat their own wastewater, and a new house, added bedrooms or a failed field call for a PE stamped design reviewed by the Oswego County Health Department.

Short answer: Granby shares its name with a soil series first established in Oswego County in 1917, and it is a wet one. Where Granby series sand sits under the field area, the seasonal water table is right at the surface, and the system has to be built up.

Sewer or septic in Granby

We did not find a published sewer service area for the Town of Granby beyond lots served from the City of Fulton, so this page does not claim one.

Practically: if your property is outside the Fulton line, you are on septic.

How a septic design works in Granby

1. Send the address and a few photos. Use the form below. Estimate in 1 hour.
2. Confirm the lot needs septic. Lots outside the City of Fulton sewer service in Granby are on private septic.
3. Deep hole and perc tests. At least one test hole six feet deep at the leaching area and at least two perc tests per system, per Appendix 75-A. Expect sand at the surface, with the depth to water telling you the system type.
4. Design and stamp. Designs are prepared and stamped by a New York licensed Professional Engineer (PE), sized at a minimum of 110 gallons per day per bedroom for a new house.
5. Oswego County plan review. Four sets of plans and the plan review fee go to the Oswego County Health Department, Environmental Health Division, 70 Bunner St., Oswego. The department engineer sends three sets back with a letter of approval or rejection, and a copy of that letter goes to you and to the Town of Granby code enforcement officer.
6. Building permit and install. With the approval letter in hand, the building permit is pulled through the Town of Granby code enforcement office. Backwell coordinates the excavation, tank, distribution box and absorption area and builds them to the approved plan.
7. Final paperwork. For an alternative system such as a raised bed, mound or sand filter, state rule 10 NYCRR 75.5 has a design professional supervise construction and certify to the health department that it matches the approved plans.

Soils and seasonal water around Granby

The Granby soil series was established in Oswego County in 1917. The USDA describes Granby soils as poorly or very poorly drained, on outwash plains, lake plains and glacial drainageways, with an apparent seasonal high water table from about 30 centimeters above the surface to 30 centimeters below it for some time in normal years. That is about a foot either side of grade.

Granby's better drained neighbors are the Colonie and Elnora sands on rises. On a lot with both, the PE puts the field on the rise and the tank on the low side only if the plumbing allows; on a lot that is all Granby soil, a mound is often the only route.

What the health department checks

Oswego County reviews septic plans itself, at its Environmental Health Division in Oswego. The state sets the floor in Appendix 75-A; a local health department may adopt stricter standards, but not looser ones without a state waiver. On a lot in Granby the review comes down to a handful of measured items:

• Mound: high groundwater at least 1 foot down, bedrock at least 2 feet down, native soil faster than 120 minutes per inch, slope no more than 12 percent, pressure distribution, and an absorption area no wider than 20 feet.
• Raised system: 1 to 2 feet of original soil faster than 60 minutes per inch, high groundwater at least 1 foot below the surface, fill that percs between 5 and 30 minutes per inch, and a taper no steeper than 1 on 3 with at least 20 feet of taper.
• Conventional trench field: at least 4 feet of useable soil above rock, tight soil and the high seasonal groundwater, with the highest groundwater at least 2 feet below the trench bottom.
• 100 feet from an absorption field to a well or suction line, 200 feet if the field sits upgrade and in the drainage path to the well, and 50 feet from the septic tank to a well.

Common Granby site problems and the design fix

Water at the surface in April

If the high groundwater is less than a foot below the surface, neither a raised bed nor a mound meets the Appendix 75-A site rules. The PE checks the rest of the lot for a better spot, or for a curtain drain that can lower the water upslope of the system.

Mound on a small lot

Mounds are smaller than raised beds, but the separation distances count from the edge of the fill taper, and the absorption area can be no wider than 20 feet. The layout has to fit the long, narrow shape along the contour.

Fast sand on the rise

Colonie sand on the dry rise can be very fast; the field needs blending if it is faster than 1 minute per inch.

What it costs

Published county fees, effective January 1, 2026: $125 for the Oswego County Health Department to review plans for one home and $250 for a commercial system, a category the county applies to businesses and rentals. Selling a house? The county lists a 4 day septic dye test with written results at $230.

Design and install are priced together in writing for your lot. Most Granby lots on Granby series soil need a mound or raised bed with a pump; dry rises can be simpler.

Grant money: Oswego County runs the state Septic System Replacement Fund. Its application says eligible projects can be reimbursed up to 50 percent with a $10,000 maximum, design costs at 50 percent up to $3,000, and every replacement must be county approved, engineer designed and covered by a local building permit. The state priority waters for Oswego County are the central and eastern Lake Ontario shoreline and the upper Little Sandy Creek and its tributaries.

Timeline

Spring testing, stamped design, county review with the $125 fee, Town of Granby permit, install.

Mound sand can be built without a settling period; raised beds with finer fill wait six months through a freeze and thaw cycle. The schedule comes with the written price.

Sources

• Oswego County Health Department: Septic Plan Review
• Oswego County Health Department: Water Supply Protection and Septic Plan Review
• Oswego County Health Department: Plan Review Fee Schedule, effective 1/1/2026
• Oswego County Health Department: Fee Schedule for Environmental Health Services, 1/1/2026
• Oswego County Community Development, Tourism and Planning: Septic System Replacement Grant Application
• NYS EFC: Septic System Replacement Fund Priority Waterbody List
• 10 NYCRR Appendix 75-A.4: Soil and site appraisal (Table 2 separation distances)
• 10 NYCRR Appendix 75-A.8: Conventional subsurface treatment systems
• 10 NYCRR Appendix 75-A.9: Alternative systems (raised, mound, sand filter)
• 10 NYCRR Appendix 75-A.3: Sewage flows
• 10 NYCRR Section 75.5: Minimum standards, design professional, alternative system approval
• USDA NRCS Official Series Description: Granby
• USDA NRCS Official Series Description: Colonie
• USDA NRCS Official Series Description: Elnora

Rules and fees as published by the agencies above when this page was written; they can change. The approved plan for your lot controls.