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You are at the (C)Copyright Protected 2006-1986 Septic System Information Website - Septic Tanks, Septic Fields, Septic System Repairs, Septic System Design - this sketch is a Septic tank
The Septic Systems Information Website - Inspecting, Testing, Designing, & Maintaining Residential Septic Systems SepticAPedia ©

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  • Septic Systems Online: This website answers just about any question you might have about buying, owning, maintaining, repairing, or installing a property with a septic system.
Our site offers impartial, unbiased advice without conflicts of interest. We will block advertisements which we discover or readers inform us are associated with bad business practices, false-advertising, or junk science. Our contact info is at inspect-ny.com/appointment.htm.

We explain how to buy, inspect, install, test, diagnose maintain and repair septic tanks and all other components of septic systems. We discuss how septic systems work, and how to provide septic system care to avoid replacing the septic system unnecessarily. We provide septic cleaning and septic maintenance procedures, septic inspection methods, septic repair guides, and septic system design information.

We give in-depth information about conventional septic tanks, drain fields, septic pipes, and septic waste handling. We describe and explain the need for and how to install alternative septic system designs for problem sites where the need is to save water or where it is difficult to dispose of septic waste. We include tables for septic tanks: pumping frequency, septic tank size, septic tank design, and clearances between septic systems, wells, and other site features and boundaries. This page organizes and links to our detailed septic system inspection, test, repair, and design articles, including our online septic systems book. Septic testing class presentations, septic system photos, septic system design sketches, septic care tables, links to products and consultants are provided. If you do not quickly find here information you need, ask by email. © Copyright 2008 Daniel Friedman, All Rights Reserved. Information Accuracy & Bias Pledge is at below-left. Use links at page left to navigate THIS DOCUMENT or our Website. Green links at left show where you are in our document & website.

SEPTIC INFO ARTICLES - Our Online Articles on Septic Systems

"How-To" Articles at our Septic System Information Website are in four groups: (these links are also at page left)

  1. Septic System Basics, septic maintenance and septic care instructions for home owners and home buyers; steps to take when buying a home with a septic tank and septic fields
  2. Septic System Design & Installation, and alternative septic designs and septic products,
  3. Septic System Inspection and Testing, how to find and diagnose septic system problems
  4. Septic System Maintenance and Repair, septic system care, maintenance, repair or replacement procedures and products

We discuss just about every septic system topic and product at this website: septic tank design, septic tank size, septic tank pumping frequency, septic tank cleaning, and septic tank inspection. If you find that something is missing just contact us and ask for it.

Information for Home Buyers or Owners
Septic System Basics - How Septic Systems Work, Septic Inspection, Septic Maintenance, Septic Repairs

"Septic tanks" are what home owners or home buyers think of when buying or maintaining a home with a private septic system. But we should be thinking about the whole septic system - since the drain field or leach field makes up half of a typical septic system cost. Septic tank care and septic tank cleaning need to be done on a regular frequency (we provide a septic tank pumping schedule table) in order to avoid ruining the drainfield. Septic tank maintenance is not enough. Proper septic system design for the level of usage and soil conditions is critical if the system is going to have a long useful life. We are also quite concerned with septic system health and safety since there are potential collapse hazards which can be fatal, and there are bacterial and pathogen hazards for both site occupants and for the environment if a septic system is not working properly. The articles listed at this website form an extensive guide to septic systems care, inspection, testing, and installation. We welcome questions and suggestions for content.


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Use links at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.


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SEPTIC DESIGN BASICS - Septic System Design: Choosing Septic Tank Size, Absorption System Size, Basic Design Notes

The full Chapter on Design Basics is at SEPTIC DESIGN BASICS.

If you need basic septic system design parameters such as finding the recommended septic tank volume and conventional recommended leach field or drainfield size, along with some notes on how to calculate these from simple water usage and site conditions, here are links to that information. Also take a look at the septic publications, septic design manuals, and onsite waste disposal standards links and articles above and below this section. I am re-writing and reorganizing this design material into a separate guide for laymen (like myself). Septic engineers already know all this stuff. Meanwhile look at the articles listed below as they will allow you to answer basic septic system design questions.

Septic Tank Sizing: to determine the required septic tank size you would need to look at article #1 to see the required tank size based on daily water volume usage and perhaps article #2 to confirm that you're estimating the water volume reasonably.

Tank Retention Time if you just wanted to know our opinion about tank size as a function of effluent retention time, see item #3.

Septic field size planning: see article #4 which sizes the field based on its percolation rate and #9 which describes performing a perc test, with perhaps a look at #10 to understand biomats and why a leach field in a wet area won't treat the effluent.

  1. Capacity: Table of Required Septic Tank Sizes: Septic Tank Capacity vs Usage is a table of required septic tank sizes
  2. Capacity: Home & Outdoor Living Water Requirements is a paper on daily water usage per household or person
  3. Designs for Septic Systems - Master List of Septic System Designs & Types, named and described
  4. Retention Time in Septic Tanks Septic Tank Pumping Guide discusses retention time and "net free area" in a tank (allowing for sludge and scum layers)
  5. Fields: How Big Should the Leach Field Be? - table of soil percolation rate vs. field size
  6. SEPTIC CLEARANCES: from wells, streams, etc.
  7. SEPTIC DESIGN ALTERNATIVES for onsite waste disposal systems - septic systems
  8. Steep Slope Septic Designs - how to install sewer lines from building to septic tank; how to install septic drainfields, leach field systems at steep or sloped sites.
  9. DEFINITIONS of common septic system and onsite waste disposal terms
  10. Drawing Library © drawings of septic system components, fields, layouts. These are educational, not engineering drawings and are © protected. Sample engineering drawings and plans wanted for the website.
  11. Soil Percolation Tests
  12. Biomat Formation in the Septic System Drainfield Absorption System - what leads to drain field clogging and expensive drainfield repairs

Use links at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website. If you just "scroll down" you'll miss some important articles. See links at page left.



INFO-SHARE SUPPORT EXPLANATION - Link Exchange & Book, Consultant, Product Listing Policy

Septic Design Consultants and Septic Service or Repair Contractors: Septic design consultants and alternative septic design engineers, septic pumping and repair contractors, academics, researchers, and other onsite wastewater industry participants can be listed in the appropriate sections of this website.

Books or other publications on septic system inspection, design, repair, maintenance, and alternative onsite waste disposal designs, technical documents, and other online resources can be listed at appropriate web pages at our site. We invite submissions of books and products for technical review. Product and book reviews are published at this website. Recent book or product reviews can be found listed at Book Reviews - Construction Practices, Building Inspection, Aerobiology, Indoor Air Quality.

Product listings: please include product literature including any available technical research. We also publish reviews products within our areas of expertise.

No Listing Fees: There are no listing fees or charges for consultants, products, or services described at our web pages. Our website policies can be read at Accuracy & Bias Pledge.

Contact us. - by email.


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More Information on Septic Systems, Building Inspection or Testing

  • Planning to call us "just to ask a question"? We're sorry but the traffic volume at this website prevents us from providing free telephone consulting. Please use email at the "contact us" link on any of our pages instead of calling. We will however provide pro-bono consulting by telephone or by email for elderly, disabled, and people with limited means. Before paying for consulting services, be sure to read the septic system inspection, care, inspection, and design articles we provide above and at the websites listed below. These will answer most basic questions about septic system maintenance, repair, and basic installation and design, and the articles offer more depth and better organization than an off-the-cuff email. We always invite email about content suggestions or corrections for this website.
  • For general septic repair advice, contact your local health department, or experienced septic engineer or contractor in your area.
  • Besides Septic Tanks, other types of tanks such as buried and aboveground oil storage tanks present similar environmental and hazard issues.

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NOTE: The master copy of the following article is maintained as a separate web document www.inspect-ny.com/septtext.htm

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Inspecting, Testing, & Maintaining Residential Septic Systems - An Online Septic System Textbook

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Septic system inspection procedures, defects in onsite waste disposal systems, septic tank problems, septic drainfield problems, checklists of system components and things to ask. Septic system maintenance and pumping schedules. © 2006-1978 Daniel Friedman, All Rights Reserved. Citation of this article by reference to this website and brief quotation for the sole purpose of review are permitted. No warranties are expressed or implied. Use of this information in books or pamphlets for sale is reserved to the author. Some technical review by industry experts has been completed-reviewers are listed at "References." New York State Home Inspection License # 16000005303

Introduction to Septic Systems - Inspection, Testing, Maintenance

What is a Septic System

A "septic system," also referred to as a private, on-site waste disposal system, receives waste water and solids from a Building's plumbing facilities (bathrooms, kitchens, shower, laundry), treats, and then disposes of the effluent from this waste, by permitting it to absorb into soils at the property. "Treatment" is accomplished by bacterial action in the "septic" or "treatment" tank and it is mostly accomplished by bacteria in the soil around and below the effluent absorption system, or "drain field." This bacterial action is needed to reduce the level of pathogens in the effluent discharges from the waste system into the soil. The principal components of a private on-site waste disposal system usually include the following:

  • piping connecting the Building to the treatment tank
  • a septic or treatment tank which retains solid waste
  • piping connecting and conducting clarified effluent from the treatment tank to a distribution box
  • a distribution box connecting the effluent line from the tank to the absorption system or "drain field"
  • an absorption system which permits effluent to drain to soils below
  • a bio-mat or bio-mass of pathogen-digesting bacteria which forms in soil below the absorption system.

Many variations on this general scheme are used, depending on local climate, soil conditions, available space, economy, and available materials. Special equipment and systems may be designed for problem or difficult sites such as rocky or wet ground, permafrost, or wet tropical marshlands. Readers who are unfamiliar with what a private septic system is and the types of systems installed should review articles and sketches of septic system components found at The Septic System Information Website

Types of treatment tanks, adsorption systems, pumps, and other special equipment are discussed in some further detail in this text, and are listed in the septic system inspection checklist data. For a more detailed introduction you may want to read our Lockwood article "What is a Septic System" and then return here to continue by using your browser's "BACK" button.

Safety Warnings for Septic System Inspectors

Providing inspection and diagnosis of on-site waste disposal systems is an extremely valuable public service which helps protect people from expensive unanticipated septic system repair costs and helps protect public health by assuring sanitary disposal of sewage and gray water waste from Buildings. More importantly though, such inspections may detect and warn about serious safety hazards at some properties. The strong warnings issued below intend to reduce septic system safety hazards for inspectors and property owners/occupants, but it is not the author's intention to dissuade inspectors from providing this valuable service.

Danger lurks at cesspools, open covers, tanks or tank covers in poor condition, and from high levels of methane gas. These risk collapse, falling, asphyxiation, and other potentially fatal hazards as well as risks of unsanitary conditions.

Septic and Cesspool Inspection Safety:

  • Collapse Hazards: Septic system inspectors face personal risks of health and safety including possible fatal system collapse or asphyxiation. Old steel tanks, thin, rusting steel or rotting home-made wood tank covers, site-built tanks and cesspools, and recently-pumped cesspools are at particular risk of collapse. Falling into a septic tank or cesspool is likely to lead to rapid asphyxiation from methane and in cases of collapse, there is risk of becoming buried. The author has consulted in cases involving such fatalities (homeowner fell into a site-built cesspool), and at one site inspection, walking near an overgrown area the author himself stepped through a rusting steel septic tank top, surviving only by throwing himself into a nearby clump of brambles! Beware of
    • flimsy, rusted, old-steel, home-made, or missing septic tank/drywell/cesspool covers
    • abandoned systems which may not have been filled-in
    • collapsed, or collapsing septic tanks or cesspools
    • possible presence of multiple components at a property, abandoned or in-use
  • Entering or Looking into Tanks: No person, except those licensed, equipped, and trained, should ever enter a septic tank. Special equipment is needed. Tank inspection (or service) should not be performed alone. Even leaning over to look into a (recently pumped) tank has been reported to cause asphyxiation.
  • Unsanitary conditions: Be alert for unsanitary conditions such as surface effluent or sewage backups into Buildings, events which risk serious viral and bacterial hazards and which indoors, may require professional cleaning.
  • Issue appropriate warnings: Septic system inspectors (and service personnel) must recognize and respond properly unsafe conditions at a site, including issuing appropriate warnings and in some cases, marking off unsafe areas where, for example, there is visual evidence of a risk of collapse hazard.
  • Avoid damaging septic system components or the Building: Improper septic testing procedures, such as flooding a dosing-system, can damage the system. Also, remember to check for leaks into or under the Building being tested when running water into the Building fixtures and drains. Don't leave water running unattended - at risk of flooding the Building.
  • Don't do anything dangerous: Inspectors should omit and report the omission of any planned inspection procedure which in the inspector's judgment is unsafe or unsanitary.

Septic Inspector Qualifications/Licensing

If you perform septic inspections you are obligated to do so with proper information, training, procedures, and in some communities a license is required. Some states (e.g. CA, CT, NJ, MA) have specific certification requirements for inspectors of septic systems, as well as specific regulations regarding the performance of the inspection itself. Be sure to obtain information pertinent to your own state, usually from the state health department or state department of environmental protection. For example, Massachusetts septic inspectors will want to look at the links and the Title 5 regulations at our page on the Massachusetts Septic Testing Law. Other links to septic system installation and inspection regulatory agencies are at our Local, State, U.S. Federal Government, & International Agencies & Resources for Septic Systems Wastewater Treatment page.

Septic System Warnings to Home Owners and Home Buyers

Septic system concerns for a Building owner start with safety. Here are some red flags:

  • Signs of collapse-possible fatal hazards: include depressions or "soil subsidence" anywhere on or around the property. Any suspect area should be roped-off and absolutely no one should walk over or even close to such a spot until it has been investigated by a professional.
  • Old or abandoned systems: such as site-built cesspools or drywells were often made with a thin steel or wood cover which with age can collapse. If the history of the site or visual observation suggests that there are or were old systems at the property, professional investigation is warranted. Improper "abandonment" (failing to fill-in a pit) can lead to sudden collapses. Signs that there may be old systems at a property might come from anecdotal evidence (ask a neighbor, ask the local septic installing or service companies), or visual evidence such as seeing abandoned waste pipes at basement or crawl space walls or floors. Don't assume that an old house which is now connected to the public sewer didn't previously have an on-site waste disposal system.
  • Septic service by untrained workers: such as aerating, agitating, or pumping out an old site-built cesspool, can lead to sudden system collapse. Prevent access over or near any such systems.
  • Unsanitary conditions such as discharge of sewage effluent to the yard surface, to a nearby well or stream, or previous septic backups into a Building deserve professional attention. Indoors special cleaning may be needed to remove bacteria or other pathogens.
  • Septic testing by inexpert "inspectors" who may not follow an adequate procedure increases the risk of a costly surprise.
  • Uninformed homeowners may not notice a danger or malfunction. Homeowners should review the safety warnings listed above. The information here is general in nature. Since conditions and requirements vary widely at individual sites, the you should obtain qualified expert advice pertaining to the specific system about which you have questions, and should not rely on this general text for costly diagnostic/repair/replacement decisions. In other words, I'll try to give you some helpful information. In exchange, don't expect me to pay for your new septic system.

The next chapter proceeds with inspection of the septic system components.

How Does Each Septic System Component Fail? - What to Look For During a Septic Inspection

This chapter discusses detailed "how to" steps instructing the investigator in how to inspect specific septic components for signs of failure. The following section will discuss types and causes of septic failure and will provide criteria that define "failure."

Before digging up your septic tank or calling a septic pumper, if you think the septic system is failed because of drain blockage or drains backing up into the Building, you should to see Diagnosing Clogged Drains: Is it a blocked drain or the septic system? - A First Step for Homeowners". If you link to that text, please return here using your browser's "BACK" button.

Inspecting Outside Waste Piping

Outside waste piping conducts sewage (black water and gray water) from the Building to the treatment tank or "septic tank," and from the treatment tank to the distribution box. These lines should be of solid, non-perforated material and need to be protected from mechanical damage (such as by vehicles). Piping extending from the distribution box into drain fields is normally perforated, though solid lines might be used if effluent is being processed by more specialized devices such as seepage pits, galleys, or a sand-bed system.

House to tank

This line may become blocked by waste, damaged by collapse of a section, or invaded by roots. Detection of these conditions is fairly easy by routing a snake or power snake from the Building drain to the septic tank. An experienced power snake operator can often tell by "feel" that a drain line is collapsed, partially collapsed, or invaded by roots. While you may make a temporary "repair" of such a condition by drain-cleaning, if the line is broken or root-invaded, you should expect to have to excavate and replace it soon.

Tank to Distribution Box

The same failures can occur on this line as from house to tank.

Drain field piping

In a conventional "drain field" of perforated pipes buried in gravel-filled trenches, a drain line may be invaded by tree roots. This is why experts advise keeping tree and shrub plantings away from drain fields. Vehicle traffic can also collapse this or any outdoor waste piping, which is why experts advise against ever driving over a drainfield or over any other septic system components.

Inspecting Septic Tank Condition

The purpose of the treatment tank or "septic tank" is to contain solid waste and to permit the beginning of bacterial action to process sewage into a combination of clarified effluent, settled sludge, or floating scum in the tank. An intact, un-damaged septic tank is normally always filled with these materials.

Only by pumping and visual inspection can actual tank capacity and condition be completely determined. Probing in the area of a tank, without excavation, is not recommended as the probe may damage a steel or fiberglass tank.

Steel septic tanks

Steel tanks typically last 20-25 years, then rust, and collapse. Before this time steel baffles may rust off (damaging the drain field with sludge) or the tank top may become rusty and unsafe. Since steel tank tops can be replaced while leaving the old tank in place, the condition of the top itself is not a reliable indicator of tank condition.

Concrete septic tanks

Concrete tanks at an existing septic installation are usually viable, but might have damaged baffles or cracks that permit seepage of groundwater in or septic effluent out around the tank. Occasionally we've seen tanks made of poor-quality concrete (insufficient portland cement) which eroded badly. If the tank outlet or absorption system have been blocked, examination of the tank interior may show that effluent is or has been above the top of the baffles (see baffles below) thus indicating a system failure discussed next.

Other types of tanks and home-made onsite systems are described below at Septic Tank Type, Capacity, Material Details

Inspecting the Condition of Septic Tank Baffles

Baffles in a septic tank are provided to keep solids and floating scum and grease inside the tank. Baffles are provided at both the inlet to the tank (from the Building) and the outlet from the tank (to the absorption system).

Broken baffles or high sludge levels can cause solids to flow out of the tank and into the absorption system. The result is reduced absorption into surrounding soil and eventual failure of the system. Floating scum thickness and settled solids thickness can be measured through access ports into the tank or cesspool. Finding solids at or covering the outlets or damaged baffles should result in report of a very questionable adsorption system and possible major repair cost.

If baffles are lost or damaged (rusted off on a steel tank or broken off on a concrete tank), they can be repaired or replaced. For example at a steel tank the contractor may simply insert a plastic piping "Tee" into the tank inlet or outlet to create a new baffle system.

However, depending on how long the tank was used without good baffles, the volume of solids and grease that moved from the tank to the absorption system will have begun clogging soils there and will have reduced the future life expectancy of the absorption system.

Baffle damage and repair, or even a complete tank replacement when the absorption system has been left alone always lead the author to warn the Building owner that the future life of the absorption system may be in doubt and that additional expense will be involved.

Inspecting the Level of Accumulated Solids, Sludge and Floating Scum in Treatment Tanks

Solids entering a septic tank are intended to remain there until pumped out during tank service. A large portion of solids settle to the bottom of the tank as sludge. Grease and floating scum remain at the top of the sewage in the tank. Baffles (discussed above) help keep solids, scum, and grease in the tank. Bacterial action in the tank make a modest reduction in the solids volume and begin the processing of sewage pathogens, a step later completed by soil bacteria in the absorption fields.

Net free area: If the sludge level becomes too high or the floating scum layer too thick, in addition to risking passage of solids out of the tank (damaging the absorption system), the remaining "net free area" of liquid in the tank is reduced. When the net free area becomes too small, there is insufficient time for waste entering the tank to settle out as bottom sludge or top floating scum. That is, for an in-use septic tank with a small net free area, the frequent entry of solid and liquid waste will keep the tank debris agitated, thus forcing floating debris into the absorption system where the life of that component will be reduced (due to soil clogging).

The importance of keeping an adequate net free area in a septic tank is the reason that tanks need to be pumped at regular intervals. Building owners who never pump a tank until it is clogged have already damaged the absorption system.

See the Massachusetts Title 5 Septic Inspection procedure discussed below for details about determining the level of floating and settled scum and sludge in the tank.

Inspecting the Septic System Distribution Box

The distribution box (more than one may be in use) connects a single effluent line from the septic tank to a network of absorption system components such as drainfield leach lines or to a network of seepage pits or galleys.

In good system design the outlet openings from the distribution box to each drainfield line can be adjusted to regulate the flow among the various absorption lines. If a distribution box becomes tipped (or clogged) effluent may be routed to only a portion of the absorption system, thus overloading it and leading to a "breakout" of effluent at the surface or to clogging and system backup. An examination of the box interior may show flood lines in the box if the drain field has been clogged or saturated in the past even if at the time of inspection the box is not flooded. If the fields have been flooded you should be pessimistic about the remaining life of the absorption system. If the box is tipped and/or effluent has not been uniformly distributed among the drainfield lines (assuming they are of equal length and in equally good soils), only a simple adjustment of the outflow may be needed. Round plugs with eccentric openings may be present or can be inserted in the D-box outlet openings to regulate flow among the individual absorption lines.

Liquid level in the adsorption system

The absorption system or "drain field" has two jobs. First, it disposes of liquid effluent by permitting it to seep into the soil below. Second, a "bio-mat" of bacteria which forms in the soil below the drainage field processes pathogens in the septic effluent to make the effluent sufficiently sanitary as to avoid contaminating nearby ground water. This distinction between successful "disposal" and successful "treatment" is important to avoid groundwater contamination but has not been addressed by regulation in every municipality. Municipalities which require a minimum distance between the bottom of the drain field trenches (or equivalent component) and the top of the seasonal high ground water table have recognized the importance of a working bio-mat and the need to provide adequate dry soil for it to function.

Even in a well-designed drainage field, eventually the soil surrounding the drainfield device (perforated pipe in gravel trench or other seepage system) becomes clogged with grease and debris. Examining an excavated cross-section of a failed drainfield will often display a black or gray band of sludge and grease of about 1" thickness at the inside perimeter of the gravel trench. When this layer of soil becomes sufficiently clogged the passage of effluent into the soil below is slowed and eventually blocked, leading to the need for replacement. Keeping a tank pumped so as to reduce the passage of debris and grease into a drain field will extend its life.

This is the most expensive problem to correct. Look for septic effluent seepage to ground surface in area of equipment or downhill from such equipment. Look for (illegal) drain field line extensions to nearby streams, storm drains, or adjoining properties where the temptation to "fix" a failing system by sending the effluent to an improper destination overwhelmed a previous owner or repair company. In some areas inspectors use septic loading and dye test. Seepage may be due to overloaded tank, failed absorption system, or blocked/broken piping (may be less costly).

An excavator or septic contractor will often explore one or more drain lines (or similar components) by excavating a portion of it to look for evidence of flooding or soil clogging. We've used a simple probe at the end and along a leach bed to check for flooding of that component. (Be careful not to break or collapse old piping.)

Types, Causes, and Failure Criteria for Septic Systems: Defining "Failed" Onsite Wastewater Treatment or Disposal

This chapter discusses types of septic system failure lists causes of each type of septic component failure, and lists the septic component failure criteria or in other words what conditions are defined as "failure"?. The detailed "how to" steps instructing how to inspect specific septic components for signs of failure are discussed in the text above.

In simplest terms, there are two visible disposal failures:

  • Toilets or other fixtures back up into the house - but first see "Diagnosing Clogged Drains and Septic Backups then return here using your browser's "BACK" button.
  • Effluent or sewage appears at the surface of the yard, or the neighbor's yard!

Septic odors may also indicate a system failure or an imminent failure. But such odors may also be produced by defects in the plumbing vent system or other site conditions. Beware, sewer gas contains methane and is explosive if it reaches a dangerous concentration inside a Building.

Typical causes range from things that are easy and cheap to repair, to a need for complete system replacement:

  • Clogged pipes
  • Broken pipes
  • Damaged tank
  • Tipped distribution box
  • Clogged/broken soil absorption piping
  • Clogged absorption soils (grease & solids)
  • Saturated soil absorption area

However there can also be treatment failures. Effluent may not back up or appear on the surface, but if insufficiently treated effluent reaches a private well or any stream or waterway, the environment is being contaminated -- an unacceptable condition. Historically many people have just worried about disposal. As the quality of drinking water deteriorates in many areas and as population grows in many previously thinly-populated areas, proper treatment has become the real concern for everyone's health.

For example, if there is not sufficient soil between the bottom of the soil absorption system trenches and the local groundwater, the local environment is being contaminated.

Other causes of onsite wastewater disposal system failure:

  • Driving over the absorption system, leach field, drainfield
  • Paving over the absorption system
  • Flooding the absorption system with surface or roof runoff, or rocky, poorly-drained or under-sized sites may simply lack capacity
  • Improper original construction , especially on rocky, poorly-drained sites (pipes settle, for example)
  • Tipped or flooded distribution boxes, resulting in uneven loading of soil absorption system lines
  • Use of septic tank or drain field additives which cl