Water damage restoration, Smithtown, NY

Local conditions

What actually goes wrong in Smithtown

Smithtown is a river town on a high water table. The Nissequogue runs north through the middle of it from the springs in Hauppauge to Smithtown Bay, and its Northeast Branch drains a chain of ponds into Stump Pond in Blydenburgh County Park. A third of the Town’s houses went up in the 1960s, many of them while a drought had pulled the groundwater down, and when it came back it came into basements. Most of the Town is still on cesspools and septic, so a saturated leaching field is what a sewage backup usually means here.

• Groundwater seeping into basements when the water table is high
• Cesspool and septic backup once the leaching field saturates
• Pond and river overflow in cloudbursts, as in August 2024
• Oil-burner puff back: about half the hamlet still heats with oil

Built in a dry decade

A third of the houses in the Town of Smithtown were built in the 1960s and two-thirds between 1950 and 1979, according to the Census Bureau’s 2020–24 estimates, and fewer than one in twenty predate 1940. Around the Northeast Branch, much of that building happened while the 1960s drought had the water table at its lowest, which is why basements that were dry when they were poured have taken water in wet years since.

The older houses are a different job. Village of the Branch keeps a historic district of fifteen houses, a church and a library going back to about 1700, and St. James has a run of nineteenth-century buildings along North Country Road. Plaster on lath and old framing take water differently from drywall, and on a clean-water loss they are usually worth drying in place rather than tearing out.

The Nissequogue, and a water table that comes back

The Nissequogue River runs about nine miles from the Hauppauge springs to Smithtown Bay, becoming an estuary at Route 25, and it is the only major Long Island river that drains north into the Sound. Its Northeast Branch is a string of ponds and streams that feeds Stump Pond, New Mill Pond on the maps, in Blydenburgh County Park.

The county’s hazard plan explains what that means for basements. The drought of 1960 to 1966 was the worst on record on Long Island and dropped the water table more than ten feet in places around the Northeast Branch. Houses went up on that dry ground, and as the water table recovered through the 1970s the seepage started. It peaked around 1979, came back in 1989–92 and again in 1995, and the Town eventually abandoned part of Steuben Road because it could not keep up with the flood repairs.

A groundwater leak does not stop when the rain does. The extraction has to outrun the inflow, the drying plan has to allow for water still arriving through the slab, and the fix that stops it next time, whether that is a sump, drainage or regrading, is a separate conversation that we will have honestly rather than sell.

Cesspools, not sewers

Most of the Town of Smithtown has no sanitary sewer. Suffolk County’s own hazard plan puts it plainly: in Suffolk only the Atlantic-coast parts of Babylon, Islip and Brookhaven are sewered. The sewers going into the downtown Smithtown and Kings Park business districts, which carry wastewater to the Kings Park treatment plant, are there because businesses could not expand on the septic systems they had.

That changes what a backup is. When a cesspool’s leaching field saturates, after heavy rain, in a long wet spell or with the water table up, the house’s own wastewater has nowhere to go and comes back through the lowest drain, which is usually in the basement. The county plan lists septic failure as a direct result of groundwater flooding, and it has happened at a Smithtown school: in 2007 groundwater rose into the septic system at Branch Brook Elementary in Hauppauge, and pumping it cost the Smithtown Central School District more than $600,000 that year.

Either way it is category three water. Stop running water in the house, because every flush and every load of laundry goes into the same full system. Pumping the cesspool is a cesspool contractor’s job; drying and decontaminating the basement is ours.

Flood damage on record in Smithtown

1. August 18–19, 2024

   The National Weather Service measured 8.10 inches in Smithtown and 7.95 in St. James. The Town closed Maple Avenue between Wildwood Lane and Darling Avenue, North Country Road north of Mills Pond Road, and West Main Street between Maple and Edgewood Avenues; Town Hall took close to four feet of water in its basement; trains stopped between Port Jefferson and Kings Park; and the Stump Pond dam collapsed, sending the pond into the streets and the Nissequogue. FEMA’s declaration covered public repairs only, with no household assistance in Suffolk.

2. 1975–1985, 1989–92 and 1995

   Groundwater flooding along the Northeast Branch and around Lake Ronkonkoma, peaking around 1979 when hundreds of homes and many roads were affected, according to the county hazard plan.

Mold · by appointment

Mold removal in Smithtown

Mold in Smithtown tends to start with the water table rather than a burst pipe. A basement that seeps every wet season never fully dries between episodes, and the growth turns up low on the walls, behind finished paneling and under carpet along the line where the floor meets the foundation.

The other common source is a cesspool backup that was mopped up rather than cleaned. Category three water leaves organic material in drywall and carpet pad, and mold grows on it long after the floor looks dry. If you are not sure what came up through the drain, assume the worse answer.

Mold remediation is booked, not dispatched

Mold remediation is scheduled work. Nobody needs a crew at two in the morning for mold growth that took weeks to appear, and a contractor who sells it as an emergency is selling the fear rather than the fix. The job starts with a survey: where the hidden moisture is coming from, how far the growth goes behind the finish, and whether the area is large enough to fall under New York’s mold rules. Mold prevention after a water loss is mostly moisture control: dry the structure to its standard, then keep indoor humidity between 40 and 60 percent.

Once a project covers more than about ten square feet, Article 32 of the New York Labor Law separates the person who assesses the mold from the company that removes it, and the same firm may not do both on one job. That is why the clearance test at the end goes to an independent assessor, not to us. How mold inspection works on Long Island sets out the whole rule.