Verified as of September 16, 2026. We re-check these pages quarterly.
The state's Septic System Replacement Program — SSRP — pays up to 75% of eligible costs, not to exceed $25,000 per property, toward replacing a cesspool or septic system with an I/A system. In Suffolk County you do not apply for it separately: the county administers the state money through the same application as its own grant.
Read the shape of it carefully
Two limits apply and the smaller one wins. The 75% is a share of eligible costs. The $25,000 is a ceiling on that share. Which one binds depends entirely on the size of your job:
| Eligible cost | 75% of it | Capped at | State pays |
|---|---|---|---|
| $16,000 | $12,000 | $25,000 | $12,000 |
| $25,000 | $18,750 | $25,000 | $18,750 |
| $32,000 | $24,000 | $25,000 | $24,000 |
| $40,000 | $30,000 | $25,000 | $25,000 |
Below about $33,000 of eligible cost, the percentage is what limits you, not the cap. Homeowners who read "$25,000" and budget for $25,000 on a $20,000 job are going to be short.
Note also eligible costs. That is not the same as everything you spend. Permit application fees are explicitly your responsibility and are not eligible under the grant programs, and so are engineering and design and the landscaping afterward.
How it is paid
This is where the state program differs usefully from the county one. State grant funds can be paid either directly to your approved installer or to you as a reimbursement after the installation is complete. The county grant only ever goes to the installer.
Either way, payment comes after the work is done, inspected and certified — the county issues payment once the inspector certification letter has been issued and the vendor has submitted payment vouchers and invoices.
Worked example
An approved installer quotes $25,000 for an I/A system, which is about the county's own average figure before engineering and design.
- Eligible cost: $25,000
- State SSRP at 75%: $18,750 — the percentage binds here, not the $25,000 cap
- Remaining: $6,250
- County SIP, up to $20,000, reaches that remainder
On that job the state is the larger of the two grants, which surprises people who assume the county program is the main event. On a larger job the balance shifts again. How the two stack works the arithmetic through in full. Your installer confirms the actual split against your approved plans and the county's grant eligibility memo.
Same eligibility, same application
The property conditions are the ones on the county's list — an existing residential home, on a cesspool or septic system being replaced, not connected to sewers and not within a proposed sewer area, valid certificate of occupancy, current town tax bill, taxes current, deed on file. New construction is not eligible for either program.
The full eligibility checklist
Is the money taxable?
No. The IRS ruled in Announcement 2022-26 that grants and rebates of this kind — payments under a state or local program made primarily to protect or restore the environment — are not counted in a homeowner's gross income. Before that ruling Suffolk was issuing 1099 forms and homeowners were being taxed on the grants; some saw tax bills rise by thousands. Homeowners who paid tax on a grant in an earlier year were told they could file an amended return.
That is federal guidance rather than advice about your return. Ask your own accountant how it applies to you.
Verified as of September 16, 2026. We re-check these pages quarterly. The 75% share, the $25,000 cap, the two payment routes and the eligibility conditions were confirmed against Suffolk County's own Septic Improvement Program page on that date; the tax treatment was confirmed against IRS Announcement 2022-26. Confirm current availability before counting on a number.
All work is performed by local licensed, permitted Suffolk County-approved installers.