When Long Island’s Skies Open Up: How Heavy Rainfall Threatens Your Septic System’s Performance

Long Island homeowners know all too well the challenges that come with the region’s increasingly wet weather patterns. A total of 22 inches fell around the region in 2024, the second-highest since tracking began in 2009, with an average of 18.3 inches over the last three years matching the highest three-year total since 2011–2013. This trend of heavier rainfall creates significant challenges for septic systems across the island, potentially leading to costly failures and health hazards if not properly managed.

Understanding the Rainfall-Septic System Connection

Your septic system relies on the soil around your drainfield to filter and treat wastewater. When a storm brings heavy rain, the soil can become saturated, making it difficult for the system to function properly. The problem is particularly acute on Long Island, where in low-lying coastal areas septic systems are commonly considered “failing” when the ground water comes close to the leaching pit. Many septic systems can fail at once when rain or storm surges submerge septic systems and/or elevate the water table.

If you have a conventional septic system, heavy rainfall that comes with floods can make the system to stop working. As rainwater floods over your drain field, the effluent from the septic tank will have no place to drain because the ground under the drain field is already saturated with water. This creates a domino effect that can quickly escalate into a serious problem for homeowners.

The Cascade of Problems Heavy Rain Creates

When Long Island experiences significant rainfall, several interconnected problems can emerge with your septic system:

• Drainfield Saturation: The soil in your drainfield needs to absorb and filter wastewater. When the soil is already full of rainwater, it cannot absorb the effluent, causing it to pool on the surface or back up into your plumbing.
• System Backups: Heavy rain can cause sewage backups, which are both hazardous and messy. When the drain field gets flooded, the excess water has nowhere else to flow but back into the septic system. This results in sewage backing up into your sinks, toilets, and other drains on your property.
• Environmental Contamination: A flooded septic system can leak untreated wastewater into nearby water bodies, wells, or your yard, posing health risks to your family and neighbors.
• Tank Damage: The septic tank itself also risks damage when there’s too much rain. When too much water gets into the tank, it causes intense pressure on the walls. This pressure may lead to cracks, leaks, or even structural failure.

Warning Signs Your System Is Struggling

Long Island homeowners should watch for these telltale signs that heavy rainfall is affecting their septic system:

• Slow drains, gurgling noises, or sewage smells
• Heavy downpours can cause your septic tank to overflow. When this happens, it releases foul-smelling gases into the air. These gases permeate your property, leading to discomfort.
• Heavy rain can also lead to gurgling sounds within your drainage systems. For instance, when you flush the toilet, you may hear sounds like an upset stomach.
• Water pooling around your drainfield area

Protecting Your System During Wet Weather

Fortunately, there are proactive steps Long Island homeowners can take to minimize the impact of heavy rainfall on their septic systems:

Reduce Water Usage: During and after heavy rainfall, limit the amount of water entering your system. Avoid running dishwashers, washing machines, or taking long showers. This will reduce the strain on your system while the drain field is saturated.

Prepare Before the Storm: Seal any possible points of entry into the septic system. Seal of all inspection points to ensure the excess rainwater will not find its way into the tank. Additionally, if your system is due for pumping, do it several weeks or several months before the rainy season – DO NOT have your system pumped right after heavy rains when the drain field is saturated, or the tank can pop up out of the ground!

Maintain Your System: It is possible for your septic system to withstand heavy rainfall but it needs to be well maintained. For this reason, you should always pump your septic tank on schedule and you should ensure it is working efficiently throughout the year.

Long Island’s Unique Challenges

Long Island’s geography and climate create specific challenges for septic systems. An increase in the elevation of the water table may result in basement flooding and compromise septic systems. The impacts of a rising water table may include an increase in the potential for subsurface structure flooding or on-site septic system failure. This is compounded by the fact that conventional septic systems and cesspools on Long Island are considered failing since they are neither designed, nor capable of removing significant amounts of nitrogen. Conventional septic systems and cesspools are not designed to remove nitrogen.

Professional Help When You Need It

When heavy rainfall overwhelms your septic system, professional intervention becomes crucial. If you experience backups or suspect your system is malfunctioning after heavy rainfall, don’t hesitate to call a licensed septic professional. They can evaluate the condition of your system and recommend repairs if necessary. It is especially important to call a professional if your system has been flooded or if you notice water pooling around your drainfield.

For Long Island residents dealing with septic system challenges, companies like Antorino & Sons understand the unique conditions of the region. They are a family-owned and operated cesspool company serving Long Island, focused on building relationships with customers and providing solutions that last, with local knowledge of Long Island’s unique soil and water table challenges. Whether you need emergency septic tank services islip terrace or routine maintenance, professional expertise can make the difference between a minor inconvenience and a major disaster.

The Bottom Line

As Long Island continues to experience increasingly wet weather patterns, protecting your septic system becomes more critical than ever. Efficient use of water should be an everyday thing, but make sure that during heavy rain you’re particularly cognizant of how you use your water to help keep your system running properly and give the rainwater time to absorb and replenish the natural water table. By understanding how rainfall affects your system, recognizing warning signs, and taking proactive measures, you can help ensure your septic system continues to function effectively even when Long Island’s skies open up.

Remember, prevention is always more cost-effective than emergency repairs. Regular maintenance, proper usage habits, and professional inspections can help your septic system weather even the heaviest storms that Long Island’s changing climate brings your way.