Home Buyer's Detailed Guide to Septic Systems - What to Ask When You Are Buying a Home With a Septic Tank
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This document provides detailed step by step inspection and testing advice for home buyers who are buying a property with a private septic system, that is, a septic tank and a leach field or drainfield or similar soil absorption system. We list detailed
questions to ask about the septic system, how to perform the visual septic inspection,
ordering the loading and septic dye test (the too-obvious results of a dye test at a problem site are in the photo at left), pumping the septic tank, and
finding additional information about the septic system. We explain how to be sure your septic inspection and septic test are conducted properly.
We tell you where to get more septic system information about a given property,
and we warn of unsanitary or dangerous site conditions.
Green links show where you are. © Copyright 2013 InspectAPedia.com, All Rights Reserved. Author Daniel Friedman.
5-HOW TO INSPECT & TEST When, Where, Why, and How to Inspect and Test a Septic System - for Home Buyers, Step-by-Step
While no septic inspection and test can guarantee 100% that all septic defects
have been found, properly conducted, septic inspection and testing procedures can reduce the chances
of a dangerous or costly surprise at a property served by an onsite waste disposal system.
When buying a home with a private septic system, septic tank and leachfield, at a minimum you should always should do steps 1-ASK ABOUT THE SYSTEM, followed by 2-VISUAL INSPECTION, and 6-ASK OUTSIDERS yourself.
If you hire an expert to inspect and test the septic
system the inspector will also perform step 2-VISUAL INSPECTION and 3-LOADING & DYE TEST.
Some home inspectors can provide this service as can independent septic engineers and a few
septic contractors. Below we tell you how to get the inspection and testing done properly. Other articles at this website give great detail about how to perform an effective and valid septic system inspection and test.
A septic pumping contractor performs steps 4-PUMP and possibly 5-5. ADDED INVESTIGATIONSL or other measures.
In case you missed it before, steps 1 and 2 are essential. Step 3 is usually a good idea.
Step 4 depends on the results of steps 1,2,3 but is usually a good idea.
Step 5 is not usually done but might be necessary.
Step 6 is what you do if you're being really thorough.
Below we discuss each of these steps in more detail.
5-1. ASK ABOUT THE SYSTEM What to Ask the Property Owners About the Septic System
Basic Questions: (An essential step) Ask the seller the following questions. Don't worry if the seller says they don't know the answers. "Not knowing" is also important information.
These questions are deliberately a bit vague in order to allow people to tell you whatever they know rather than cutting off or suggesting answers.
Convey the answers to these questions to your septic test consultant.>
- How old is the property?
- Is the property occupied or vacant? If occupied, for how long and by how many occupants? If vacant, for how long?
- How long has the seller owned the property?
- Where is the septic system? [Tip: if the owner has been at the property for years and does not know where the septic tank is located, they have never pumped it - which looks bad for the leach field.
On the other hand, if they know exactly where it is and if it has an easily-opened access cover, you might wonder if it's being pumped unusually often - which could also be a telltale.]
- What is installed? [Tip: this means: is it a conventional tank and drain field? Is the tank concrete or steel? How big is the tank? Are there separate drywells or seepage pits? If so the
owner may have had a concern with the capacity of the leach field.]
- What is the service or repair history of the septic system? [Tip: if the system has received regular pumping that's good. If it has
never been pumped, you should be pessimistic about the remaining life of the leach field. If a new tank has been installed but connected to
old fields you should be pessimistic about the leach fields. If everything was installed new last year, you may be a lucky buyer.]
- When was the tank last pumped? [Warning: if the seller offers to "have the tank pumped for you" ask them not to do so
before your inspection. Pumping the tank prevents testing the drain field.]
Other useful but less reliable sources of information about your septic system include:
- Ask for any drawings regarding the actual location (an "as-built drawing) of the existing septic system. However while you should ask for drawings and records, you should never completely trust them.
For example, a septic system may not have all of its components installed just as they were
placed on a drawing. The excavator could have hit bedrock or other obstructions and moved things a bit.
- Ask for the records regarding maintenance of the system; Has the septic tank been pumped at a frequency of at least 3 to 5 years?; What pumping
contractor was used?; If the system contains a pump. how often has it been maintained?; If major repairs have been made, when and to what extent?
- Ask about the past performance of the system. Have any of the symptoms described earlier manifested during the life of the system?
5-2. VISUAL INSPECTION: Make a Visual Site Inspection for Signs of Septic Trouble or Site Limitations
Visual Inspection: (An essential step) Make a visual inspection of the property. Look for wet areas, smelly areas, rocky areas, areas of recent excavation.
Also make note of the location of and distance to nearby streams, private wells, ponds, buildings, property lines, and rocky areas, and areas
of trees and shrubbery.
[Warning: be very alert for evidence of sink holes or subsidence. Do not walk over anything suspicious as you might step into or fall
into a collapsing system.]
Once the locations of the septic tank and leaching fields are known, walk
over the entire area and observe whether there is any evidence of a sewage
overflow condition. Greener grass in the leaching area may not necessarily
indicate a system problem. If, however the area is completely saturated and
odorous you should be very concerned. It most likely indicates an active
failure.
Try to get a sense of how natural conditions are effecting the capacity of
the property to disperse water.
- Is the sewage disposal area located In a
depression which would have a tendency to collect run-off of rain water? Is the
lot flat? Is there a water course of wetland (swamp) near the leaching system?
- Is the system virtually at the same elevation as nearby wetlands?
- Are
there steep slopes and/or ledge outcrops which reduce the available area for
leaching purposes?
All of the above factors could indicate that the existing
system will experience difficulty or, that there may not be much additional
area suitable for sewage disposal on the lot if needed in the future.
More Reading:
Table of Required Septic Clearances:
Distances Between Septic System & Wells, Streams, Trees, etc.
Table of Required Well Clearances: Distances Between Drinking Water Wells and Septic Systems, Treated Soils, Farm buildings, & Other Site Features
5-3. LOADING & DYE TEST How to Perform a Home Buyer's Septic Loading & Dye Test
This document section is maintained in a separate web page
5-3. LOADING & DYE TEST.
Text is repeated below for people who scroll down instead of using the left-side links to navigate the HOME BUYERs GUIDE to Septic Systems.
Most home sales are contingent upon a home Inspection. But home inspections do not
usually include a test of the existing septic system. Septic Tests are beyond the scope of a professional home inspection
but these septic tests are offered as an additional for-fee service by many home inspectors who
serve areas where private systems are common. The photo at above left shows septic dye leaking out of a main house drain just after it was
flushed down a toilet above.
Hire your own septic test consultant who
has experience with and is familiar with septic loading and dye testing standards,
a licensed septic inspector (in states which license this specialty such as MA), or a licensed
septic system installer, who performs a great deal of work in the particular
town. They can give you advise as to the condition of the soils and septic
systems In the area and what might be expected (especially pertaining to costs)
if/when you find problems with the existing system.
This photo shows a small property bordering on a river. We
were told that a "new septic system" was installed but I could not see where a conventional tank and drainfield could
possibly fit except below the driveway. Because of the nearly overwhelming temptation at such sites to pipe septic
effluent directly into the river, we performed a septic loading and dye test to see if the river would turn red.
The river did not quickly turn red but after less than 100 gallons of water had been run into the septic system our
red septic dye appeared at the basement entry platform at the edge of the driveway, as shown in the photo used at the top of this page.
Warning:: Unfortunately many of the
people performing these tests perform only a perfunctory test such as a low-water volume test (50 gallons is meaningless)
or use an insufficient
amount of tracer septic dye. Therefore, the conclusions reached from these tests are often
misleading. Be sure your test is performed by an expert and that an adequate volume of water is used.
We specify no less than 50 gallons per bedroom or 250 gallons, whichever is greater.
Warning: if you hire a separate consultant to just perform the septic inspection and dye test
you're at risk of getting a bad deal. It takes time to get enough water into the system to perform
a reasonably aggressive test. It's economical to do this test if overlapped with other work at the
site (like a home inspection). But someone coming to the site just to do the septic test is not
going to wait around for 2+ hours for water to run into the system - you're likely to get an
inadequate test. If you must use a third party just for this test be sure to review the test parameters
and agree on them ahead of time.
Warning: Do not pump the septic tank before the loading and dye test.
Depending on its size an empty septic tank could require 2-3
days' worth of water to re-fill the tank. An empty tank means that the "loading water" run into the
system during the dye test procedure is simply filling the tank rather than testing the ability of the
drain field to absorb effluent.
5-3a WHAT'S A DYE TEST? What is a Septic Dye Test?
This procedure puts a test volume of water into the
system to look for evidence of a blocked pipe or for breakout of septic effluent at the yard surface - indications of the need for repair.
If you are looking at a completely new home and septic system you might omit this test but don't assume that new systems are immune to
failures. Pipes settle and break or systems can be improperly installed. If the tank was pumped immediately before your inspection
you should be suspicious, and you might defer the loading and dye test as it may be unable to put enough water into the system to
test the drain fields. The dye itself is just a coloring agent to identify water that may appear at the yard surface. It's the test volume
of water that's important.
If the dye appears on the
ground or appears in a brook or catch basin the system is in failure.
We have seen dye breakout in 15-30 minutes in many instances where there
was no pre-existing wet spot but where subsequent excavation confirmed that
the system was either damaged or in failure.
More Reading:
Performing a Septic Loading and Dye Test,
complete details of the septic loading and dye test procedure, test data forms, septic loading
test water volumes, septic tracer dye quantities, critical observations.
5-3b TEST LIMITATIONS Septic Dye Test Limitations
Warning: if dyed effluent or water does not break out on the property
surface, this does not necessarily mean the system
is functioning or will function properly in the future. There
are certainly cases in which effluent does not appear at the surface for some time,
possibly up to five days, and there are other defects which predict upcoming expensive repair
or replacement of the system but which are not detected by loading the drain field.
National data collected among professional home inspectors between
1985 and 1995 indicated that a significant number of inspectors performing dye
tests discovered total failure of the septic system within 20 to 30 minutes of
beginning testing. We agree that a dye test is by no means a complete test of a
system, that the other measures suggested here are extremely valuable, and that
the volume of water used is critical: too little or too much can both be
serious mistakes. If a wet area or soggy area is present, dye has been found to
appear in the short time indicated. However beware: NYS DEC has found dye
appearing in nearby streams as late as five days following a septic dye test in
cases where effluent migrates through considerable ground area before entering
a stream.
5-3c FLOODING TESTS What Are Septic "Flooding Tests"?
Some authors describe an attempt to "flood" the septic system with 1000 gallons of water to attempt to force a
sign of system failure to manifest itself. A typical home with a private well and pressure tank should be able
to deliver 5 gallons per minute. If this test were performed overlapped with a home inspection (a 2 1/2 to 4 hour procedure)
one could obtain this test volume. Warning this test should not normally be attempted. Placing 1000 gallons
of water into a septic system in two hours is likely to exceed its design parameters, and in the case of certain
systems, it could actually damage the system. While all inspections and tests should aggressively seek to protect
the interests of the parties involved by being thorough, a test which exceeds system design parameters would be improper.
5-3d PROBE TESTS of Septic Fields & Locating Septic Components
Probing is a procedure whereby the Inspector attempts to locate
the "key" elements of the system (septic tanks and leach fields) and determine
if they are experiencing hydraulic distress (meaning the septic tank and fields
are flooded). If a probe in a leach field produces a
hole which fills rapidly with water this test indeed indicates a problem with the system.
But if a probe does not produce this condition, the test has been unreliable since
it may be during a time of dry soils or a day when
very little water was used by the homeowner or the home in fact may have been vacant.
This test, if performed, must be done by an expert, with caution, and is inconclusive
if it does not detect a problem.
WARNING: probing can damage buried equipment such as fiberglass
septic tanks or tank covers or plastic septic drain lines. Further, there is little assurance that the probing is
done in the area where a problem is present.
More Reading:
Septic System Inspection Methods and Procedures
Septic Failure Causes: How Does Each Septic System Component Fail? - What to Look For During a Septic Inspection - Step by Step Diagnosis
Inspecting & Testing Septic Systems: Online Book, Inspection, Test, Diagnosis, Repair, & Maintenance: Our Online Septic Book: Septic Testing, Loading & Dye Tests, Septic Tank Pumping, Clearances, details of onsite waste disposal system inspection, testing, repair procedures.
5-4. PUMP THE TANK When and How to Pump the Septic Tank When Buying a Home
After performing the septic loading and dye test and obtaining
whatever historical maintenance and repair information you can obtain from the prior owner,
you may want a septic
contractor to located, open, pump, and inspect the septic tank. The decision to include
this next and more invasive step depends on what you have already learned about the
age, history, and probable condition of the system. The pumping decision should be advised by
the visual inspection, site history, and loading/dye test results.
Warning: [Repeated from the Dye Test discussion]
Do not pump the septic tank before the loading and dye test. Depending on its size an empty septic tank could require 2-3
days' worth of water to re-fill the tank. An empty tank means that the "loading water" run into the
system during the dye test procedure is simply filling the tank rather than testing the ability of the
drain field to absorb effluent.
Pumping a septic tank prior to purchasing a home may or may not be necessary,
depending on the age and service history of the system
and the results of the visual inspection and loading and dye test.
For example, if a tank is less than two years old or was pumped in the last year,
and if there are no other signs of septic problems at the site, we might defer
the pumpout. In this case we would strongly recommend calling the pumper to ask
about the condition of the system at the time they last cleaned it.
But pumping the tank for diagnostic reasons can be helpful in any case.
Important additional information, available when the tank is pumped,
can tell you if it was past-due for pumping (risking damaging the drain fields) and if it is damaged. You'll also know exactly where the tank
is, if it's concrete, steel, fiberglass or home made, if it has been damaged, if the baffles are broken,
if the tank has been flooded (indicating a blocked drainfield), and if the tank has a safe cover.
Even if there are no signs of trouble from the inspection and dye test, if nothing is known about the system history, or if
it is known that the system has not been opened and pumped in 3 years or longer, this step
is strongly advised. If the septic tank has been pumped quite recently, you should call the pumping contractor to ask
if, at the time of pumping, the contractor observed any indications of system problems or upcoming system repairs.
5-5. ADDED INVESTIGATIONS Additional Septic System Physical Investigation Measures
Additional steps which are not normally done but which may be performed if there is evidence of system damage or failure are listed next.
These steps would ordinarily be
performed by a septic contractor who installs or repairs septic systems. Some septic pumping companies also perform septic repairs and field
investigations. A septic engineer may be needed if you are expanding a system or if you require design to repair a system on a difficult site.
- Find and Open the Distribution Box which connects the pipe from the tank to the network of drainfield lines.
- Excavate suspicious areas such as wet areas at in the leach field, subsidence areas.
- Perform soil percolation tests or "Perc tests" to evaluate the ability of the soils to absorb effluent. This involves digging
a hole, pouring in water, and measuring the time for a given volume of water to be absorbed into a given square foot area of soil.
- Soil & Site Research to include determination of the soil quality, the depth of the seasonal high water table in the
ground below the leach area, etc. - this work may be needed if a system is to be replaced or relocated, especially at a difficult site.
5-6. ASK OUTSIDERS Other Information Sources About Septic Systems
- Talk to neighbors about the general performance of septic systems In the
area and specifically the system on the property you're Interested In. However,
this is suggested only for those comfortable approaching this subject with
strangers and with the realization that the information gathered may not be
totally factual for various reasons (devaluation of their own property; not
wanting to spoil the sale of a friendly neighbor, etc.)
- Soil Maps: Use of Soil Conservation Service County Soil Maps (through the town
sanitarian), try to identify the type of soil most likely present on the site
in order to predict the feasibility of future repairs to the existing leaching
system.
- Water Meter Readings: Obtain water meter readings (if the home is serviced by a municipal water
supply) to determine what the present occupants of the home are utilizing. Then
compare those results with what your family is presently using. If your family
Is using significantly more water than the former occupants you may be asking for
trouble if the sewage system is undersized by today's
standards.
- Septic Tank Pumper Records: Additional useful information which may be available from the service
company who has pumped the tank recently includes the following:
- Type of tank material - old steel tank may be at or end useful life
- Tank size - along with usage determines appropriate pumping frequency and system capacity
- Evidence of damage to tank components - broken baffles mean the leach fields are probably ruined
- Evidence of backflow into the tank during start of pumping - indicates flooded leach field, probably failed
- High sludge level and/or excessive floating scum level - indicate high risk of having pushed solids out into the leach field, destroying it
If the system has not been cleaned in several years and if the seller will
permit, have the tank pumped to obtain this additional information. Typical
pumpout fees are around $100. if excavation is not necessary. If the tank
location is unknown extra costs will be involved to locate and excavate it -
steps to which a seller is likely to object.
Health Department: Go to Town Health Department to Review the Property's Septic System Information File.
- Ask the town sanitarian to review the file with you. Is there enough
information in it for him/her to give you an opinion on how the existing system
and/or lot meets present health code requirements?
- Ask for the records regarding maintenance of the system; Has the septic
tank been pumped at a frequency of at least 3 to 5 years? What pumping
contractor was used? If the system contains a pump, how often has it been
maintained?; If major repairs have been made, when and to what extent?
- Your goal is to, confirm and supplement information received from the
property owner.
- Obtain guidelines concerning the proper maintenance of a subsurface sewage
disposal system.
- If you are contemplating an addition to the home or plan on renovating an
unfinished basement discuss the possibilities with the sanitarian and determine
the procedures you would have to follow to accomplish your plans. In wm cases
it will not be possible to "enlarge" an existing home.
- Ask about the general neighborhood, the frequency of repairs, ability to
install proper size repair systems, average life of systems in the area,
etc.
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Technical Reviewers & References
Related Topics, found near the top of this page suggest articles closely related to this one.
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
 The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 25th Ed., 2012, is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. Field inspection worksheets are included at the back of the volume. Special Offer: For a 10% discount on any number of copies of the Home Reference Book purchased as a single order. Enter INSPECTAHRB in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
Or choose the The Home Reference eBook for PCs, Macs, Kindle, iPad, iPhone, or Android Smart Phones. Special Offer: For a 5% discount on any number of copies of the Home Reference eBook purchased as a single order. Enter INSPECTAEHRB in the order payment page "Promo/Redemption" space.
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- Inspecting Septic Systems: Online Book, Inspection, Test, Diagnosis, Repair, & Maintenance: our Online Septic Book: Septic Testing, Loading & Dye Tests, Septic Tank Pumping, Clearances, details of onsite waste disposal system inspection, testing, repair procedures.
- Advanced Onsite Wastewater Systems Technologies, Anish R. Jantrania, Mark A. Gross. Anish Jantrania, Ph.D., P.E., M.B.A., is a Consulting Engineer, in Mechanicsville VA, 804-550-0389 (2006). Outstanding technical reference especially on alternative septic system design alternatives. Written for designers and engineers, this book is not at all easy going for homeowners but is a text I recommend for professionals--DF.
- Builder's Guide to Wells and Septic Systems, Woodson, R. Dodge: $ 24.95; MCGRAW HILL B; TP;
Quoting from Amazon's description: For the homebuilder, one mistake in estimating or installing wells and septic systems can cost thousands of dollars. This comprehensive guide filled with case studies can prevent that. Master plumber R. Dodge Woodson packs this reader-friendly guide with guidance and information, including details on new techniques and materials that can economize and expedite jobs and advice on how to avoid mistakes in both estimating and construction. Chapters cover virtually every aspect of wells and septic systems, including on-site evaluations; site limitations; bidding; soil studies, septic designs, and code-related issues; drilled and dug wells, gravel and pipe, chamber-type, and gravity septic systems; pump stations; common problems with well installation; and remedies for poor septic situations. Woodson also discusses ways to increase profits by avoiding cost overruns.
- Country Plumbing: Living with a Septic System, Hartigan, Gerry: $ 9.95; ALAN C HOOD & TP;
Quoting an Amazon reviewer's comment, with which we agree--DF:This book is informative as far as it goes and might be most useful for someone with an older system. But it was written in the early 1980s. A lot has changed since then. In particular, the book doesn't cover any of the newer systems that are used more and more nowadays in some parts of the country -- sand mounds, aeration systems, lagoons, etc.
