How to care for a septic system

by Karina Coombs

Without the option of town sewage, individual septic systems serve the needs of nearly 5,000 Carlisle residents. As one of the most important and expensive systems in a home, maintaining its health provides significant savings to homeowners in terms of repair or replacement while also ensuring the integrity of the town’s groundwater. 

Did you know that routinely putting coffee grounds down your garbage disposal could destroy your septic system? Or that having a garbage disposal requires your septic tank to be pumped twice as often as those without one? Many of us dread laundry day where we run washes back to back, but did you know that large amounts of wastewater are actually taxing to a system and can flood your leach field? Thankfully, keeping your septic system in good shape is easy and just requires some simple changes around the house.

Maintenance is key

According to the Massachusetts Executive Office of Energy and Environmental Affairs, one third of US households rely on septic systems for waste removal. These systems deposit one trillion gallons of waste underground each year, making safe disposal crucial to preventing disease and groundwater contamination. 

Everything that goes down a home’s drain ends up in the septic tank. Inside the tank, light solids and grease (known as “scum”) float to the top, while solid materials or “sludge” settle to the bottom and are partially broken down by naturally occurring microorganisms. Wastewater that has been partially treated will then leave the tank and move into the leach field where it is broken down again in the soil. Anything that disrupts or overloads this process can cause problems.

The typical reason for a failed septic system is a lack of general maintenance. With replacement costs running between $10,000 and $50,000 or more, pumping and inspecting the system regularly, conserving water, monitoring the leach field and being mindful of what goes down the drain can go a long way to helping homeowners get the most life out of their system, typically 25 to 30 years.

Pumping and inspection

The Massachusetts Department of Environmental Protection suggests a pumping schedule of every three years. Carlisle Board of Health (BOH) Agent Linda Fantasia recommends homeowners have their septic tanks pumped every two, explaining that the cost of pumping is considerably less than repairing or replacing a system. The use of garbage grinders is not advisable because it adds additional material to the tank that is not typically broken down. If one is in use the septic tank should be pumped annually.  

During pumping, a licensed hauler (pumper) will also inspect the overall health of the tank and alert homeowners to potential problems. BOH member Catherine Galligan makes a point of watching the process at her own home, explaining that while it is unpleasant she learns a lot about the integrity of the system. “If they can do it for a living, I can do it for 40 minutes.” 

Both Fantasia and Galligan suggest that homeowners become familiar with their septic system, knowing the location of the tank and the leach field. Fantasia suggested putting a marker above the tank and distribution box (D-box) or having the tank lid raised for easier access. Knowing where the septic tank is located will also save time and money. “If you have no idea where your septic tank is it will cost more to pump if they have to dig to find it,” explained Fantasia. Homeowners should keep all pumping and inspection records in a file as well as a diagram of the system’s layout. 

Conserving water

Conserving water is the next step in maintaining the health of a septic system because systems can only treat so much wastewater at a time. It is estimated that for every gallon of water that goes down into the tank, another gallon is pushed into the leach field. Too much water in the system at once can cause it to back up into the house or flood the leach field. Too much water can also stir up the solid material in the tank without enough time for it to settle, allowing solids to pass into the leach field and clog the system.

To conserve water around the house, leaking faucets or toilets should be fixed, low flow showerheads could be used and homeowners should consider low-water-usage washing machines and dishwashers and then only using these machines when full. Laundry should be spread over several days, hot tubs should not drain into the system, and exterior drains should be directed away from the system. Fantasia also explained that water softeners should not drain into septic systems and instead should have a separate discharge line and drain into a dry well. 

Monitoring the leach field

The leach field is the last opportunity for wastewater to be treated in a septic system and is the costliest component to repair. Fantasia explained that nothing but grass should be planted atop the field, ensuring significant roots do not disturb the system. Vehicles should not drive across the field, nor should heavy structures be placed upon it. Fantasia added that homeowners should also be mindful of placing deep stakes into the soil. Any sign of standing water, odor, discoloration of grass (too green), or soft spots near the field could suggest a problem and warrant a closer inspection. 

What not to put down the drain

One of the biggest things homeowners can control however, is what they choose to put down the drain. Fantasia and Galligan explained that the only paper product that should be flushed is toilet paper, preferably white. Paper towels or napkins, diapers, baby wipes, feminine products, or other such items should be thrown away and not end up in the septic tank as they will not break down. Slow draining of sinks and toilets can be a sign of system failure, as can sewage backup and odor in the home. 

So they do not end up in the leach field, pharmaceuticals should never be flushed down a drain and instead should be dropped off at the pharmaceutical drop box inside the Carlisle police station. For the same reason, the usage of household chemical cleaners should be minimal, with products containing bleach, ammonia, or anti-bacterial additives avoided. Drain cleaner is not advisable at all. Each of the aforementioned products has the ability to destroy the organisms in both the tank and the leach field that break down waste. 

Along with food scraps and coffee grinds, cooking oil and grease should also be kept out of the drain. Strainers are available in different sizes for sink drains to catch this debris. Latex paint should also be kept from drains. Paintbrushes should be first cleaned in a bucket outside before being rinsed off inside. 

What to do for a failing system

If you think you have a problem with your system, contact a licensed vendor for more information. A list of vendors licensed within Carlisle is available at the BOH website:

Should your system need repair or replacement, make sure to get estimates from a number of vendors and contact the BOH for requirements. Massachusetts currently offers a tax credit for up to $6,000 for septic repair and Carlisle participates in the state’s Community Septic Loan Program, which offers up to $40,000 for failed septic systems for qualified homeowners: ∆