Cesspool Replacement Cost in Suffolk County, and How the Grants Stack

Replacing a cesspool with a nitrogen-reducing I/A system is a big job, but in Suffolk County most of the bill can be covered by grants. Here is what drives the price, what each grant pays, what stays on you, and what the system costs to run once it's in.

Quick facts. County SIP grant: up to $20,000, paid to the installer. State SSRP grant: up to 75% of eligible costs, capped at $25,000. Maintenance: county grant funds the first 3 years, then about $300 to $600 a year. Electricity: about $75 to $250 a year. You pay: permit fees, design, landscaping, and anything over the grants.

What an I/A system costs to install

No public agency publishes a fixed price, because every lot is different. The best published guide comes from the Peconic Estuary Partnership, which works with Suffolk County on the grant program. It puts the average total cost of a nitrogen-removing I/A system at about $20,000 to $30,000, plus the cost of engineering and design. When the county first ended in-kind cesspool replacement, its overview gave an average I/A design and installation cost of $19,500. Prices have gone up since then, so treat that as a floor, not a quote.

The county's homeowner fact sheet lists what moves the price on your property:

• Soil type on the lot
• Depth to groundwater
• Site constraints, such as equipment access and where the house and other structures sit
• Site restoration. The county warns there will be extensive disruption during installation.
• Tank size, which depends on the number of bedrooms
• The I/A technology you choose

The only real number for your house is a written quote from an installer who has looked at the site and the design. That is why it pays to compare a few.

Grant 1: Suffolk County Septic Improvement Program

• Up to $20,000 per property, depending on whether your project qualifies.
• It is not a reimbursement. The county pays the grant directly to your installer after the installation is complete and inspected.
• You must pick an installer from the county's SIP Approved Installer List.
• You must apply for and be issued the grant before the I/A system is installed.
• It funds the system's maintenance for the first 3 years after installation.

Grant 2: NYS Septic System Replacement Program

• For an enhanced system, the state pays up to 75% of eligible costs, capped at $25,000 per property.
• Only systems listed as Residential General Use or Provisional Use approvals on Suffolk County's I/A list qualify for the 75% level, because they have been tested to meet 19 mg/L of total nitrogen.
• It can be paid to the installer or reimbursed to you, after installation.
• You don't file a separate state application. The county runs both programs, and one application on its site applies to both.

The state lists these as eligible costs: design and installation, the system and its components, enhanced treatment technology, and design work needed to complete the approved design. It lists these as ineligible:

• Routine pump-outs, unless needed to replace a tank
• Government permit fees
• Sales tax
• Interest, late fees, fines and penalties
• Non-essential site beautification and interior plumbing changes
• Administrative work by the engineer, and expenses that aren't documented
• Connecting to a public or community sewer

Grant 3: town rebates on the East End

Suffolk County points homeowners in three towns to extra money:

Southampton and Shelter Island only rebate costs that the county and state grants did not already pay, so the town money fills the gap rather than adding on top. In other towns, including Brookhaven, Riverhead and Southold, the county does not list a town rebate.

What you still pay

Suffolk County lists these as the property owner's responsibility:

• Permit application fees
• Permitting, engineering and design
• Landscaping after installation
• Maintenance after the grant-funded period
• Anything above the grant amounts

In Southampton and Shelter Island, the town rebate can pick up some of these, such as design and basic restoration. Check the town page for the exact list.

What it costs to own an I/A system

These are the county's estimates, which it says are based on information from vendors:

Annual professional maintenance is required, and a grant-funded system can't be removed or switched off without the county's written approval. The county grant pays for the first 3 years. If you are in the Peconic Estuary groundwater contributing area, a separate county program funded by the Peconic Estuary Partnership reimburses up to $500 a year when you renew a maintenance contract, while funds last.

If the power goes out, the county says the system keeps working like a conventional septic system unless you have a backup generator.

Help with the gap

Shelter Island's town page describes low-interest gap loans of up to $10,000 from the Community Development Corporation of Long Island (CDCLI), a nonprofit lender, to cover the difference between the grants and the contract price. These loans are not from Suffolk County. Ask CDCLI for current terms. In Brookhaven, income-eligible owners can also ask about the Town's 0% deferred loan for home repairs, which can include the sanitary system.

Next: how to apply for the grants, step by step.