Learn
How it Works

Leach Field
Typical Layout
What Is A Septic System?
An on-site sewage treatment system commonly comprised of a septic tank and a leach field.
What Is The Tank's Role?
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Receives all wastewater from dwelling including toilet, bath, kitchen, and sometimes laundry, depending on setup
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Separates organic solids (scum), fats, grease, and soaps; and inorganic solids (sludge). Scum floats to the top of the tank while the sludge settles to the bottom
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Creates the most important middle section of clear wastewater (effluent). Only effluent should exit via the outlet baffle to the leach field
What Is The Leach Field's Role?
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Effluent enters the distribution box (D-Box) and then proceeds into the absorption area for further treatment by the soil
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The partially treated effluent is pushed along into the
drain field for further treatment -
Once effluent reaches the soil area, it percolates into the soil which provides final treatment by removing harmful bacteria, viruses, and nutrients. Now the cycle is complete and the water can re-enter the groundwater safely
Maintenance
DOs & DON'TS
DO
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Keep a record of tank location and services
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Keep tank cover(s) accessible
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Pump your tank regularly
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Be proactive with what goes down the drain/toilet
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Repair leaky plumbing fixtures no matter how small
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Divert drains and surface water away from the system
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Minimize water usage after heavy rain
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Space out your laundry washes to different days
DON'T
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Use a garbage disposal (limit use if you already have one)
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Overuse bleach, disinfectants, cleaning products
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Dump chemicals such as solvents, paints, paint thinner, or pesticides down drains
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Flush wipes*, feminine products, cigarettes, plastics, or other inorganic material down a toilet
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Park, drive, build, put plants with deep roots, or place heavy objects over the system
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Use excessive amounts of water
*This includes the so-called "flushable" wipes. Learn more

Tip: If you don't know where you septic tank is, winter could be a good time to mark the spot where the snow melts first
Trouble Symptoms
Your septic system may be failing if one or more of the following conditions exists:
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All of the drains from the house are slow
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There is a persistent wet area over the leach field
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Sewage is surfacing near the septic tank or distribution box
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There is sewage seeping through the foundation
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The liquid level in the leach field is at the top of the crushed rock layer, the chambers, or other underground structures
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The vegetation over the leach field is greener and lusher than over adjacent areas in the yard
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There is a septic odor in the yard at times or constantly
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There is back flow from the leach field when the septic tank is pumped
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The septic tank needs to be pumped very frequently
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The septic tank outlet baffle is damaged or missing
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Rainwater seems to take longer to disappear over the leach field than over adjacent areas in the yard
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Well water is contaminated

Is your toilet paper septic safe?
Learn how to test your toilet paper for break down effectiveness in this video:
See which brands of toilet paper break down the best here:
Additional Resources
Unsure where your tank is located? Request a copy of the septic plans using this form
New Hampshire Department of Environmental Services
https://www.des.nh.gov/land/septic-systems
Wastewater: Where does it go?
