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Septic & graywater filter maintenance: this document discusses when & how to clean or maintain septic filters and graywater filters to protect the septic drainfield, drywell,
or absorption system from clogging. Septic filters are placed either in the septic tank at the outlet tee or in a separate chamber outside of and close to
the septic tank. Graywater filters may be placed at the inlet to a drywell or graywater disposal system to catch solids of various forms and thus to significantly extend the life of a drainfield, drywell, or soakaway bed. But how do we know when to clean the septic or graywater filter & how do we know if it is clogging? We also discuss methods for monitoring the condition of the septic or graywater filter.
machine filters are often installed at the clothes washer outlet hose.
Media filter systems (which unlike filters at the septic tank or drywell, are used to treat septic effluent) are discussed at Using Septic Media Filters as Components of Alternative Septic Systems for Difficult Sites.
Citation of this article by reference to this website and brief quotation for the sole purpose of review are permitted. Use of this information at other websites, in books or pamphlets for sale is reserved
to the author. Reviewers & content suggestions are welcomed and are listed at "References."
Septic filter or gray water filter maintenance is essential to keep the septic system working properly.
Failure to clean the filter can lead to slow drainage in the building, clogged drains, and backups at
the septic tank or drywell. The advice here combines suggestions from septic filter or screening product manufacturers
and the experience and field reports from people whose septic system design includes filters and screens.
Septic or graywater filters need regular cleaning
Installing a septic effluent filter or gray water filter on a wastewater disposal system can be a
comparatively inexpensive, cost-effective
step you can do to extend the life of the drain field or soil absorption system.
However, as the filter clogs it can cause a too-sluggish release of effluent into the drainfield and it can even
result in a septic system backup. For this reason if you install a septic effluent filter or a gray water filter,
regular inspection (monthly) and filter cleaning on schedule are very important.
These steps involving use of effluent filters, pumping the septic tank on schedule,
conserving water use, and watching what you flush down the toilet comprise a list of key steps to get the most life out of
onsite wastewater treatment and disposal systems.
Is a septic filter actually needed at a septic tank?
According to NSF, "Solid accumulation in the filter will cause poor performance of the septic tank,
but creates a problem that is far easier and less expensive to clean and maintain than solids accumulation in the drain field.
like to see a washing machine filter installed at homes using a septic tank since the lint (and sometimes
clots of un-dissolved detergent) can add significantly to septic system clogging.
We often recommend
a septic effluent filter to help protect drainfields which themselves have limited capacity or at sites
with poorly-absorbing soils.
If the septic tank is maintained properly, including frequent inspection for solids accumulation and removal, then a filter may not be necessary"
Does pumping the septic tank mean the septic filter does not need to be cleaned?
Some people argue that if the tank is pumped regularly (SEPTIC TANK PUMPING FREQUENCY), cleaning the septic filter "may not be necessary".
This is a questionable notion at best. Think of it this way: if a septic filter or graywater filter never ever needed to be
cleaned or replaced, it must not be filtering anything out of the effluent stream in the first place! In any case, local building code or health
departments may require an installation permit and/or may require that the septic filter meet NSF/ANSI Standard 46.
You don't have to install a septic filter at the septic tank to protect the drainfield from clogging if the septic
tank is properly maintained - that is, pumped on an appropriate schedule, and provided that you don't do something
foolish such as use septic system additives (such as yeast) which cause agitation or frothing inside the septic tank, interfering with
sludge settlement and formation of the scum layer. Interfering with these processes risks pushing high levels
of suspended solids into (and clogging) the drainfield.
Having a septic filter installed adds extra protection for the drainfield and extends the probable life of the drainfield
If you have a septic filter or graywater filter installed, it is very important to clean the filter regularly
How often to clean the septic or graywater filter
The actual cleaning frequency needed for
sewage filters, filtering basins, infiltrator chambers, wastewater filters, or effluent filters may range from every few
months to every few years, depending on system usage, wastewater flow, septic system design, and the type of filtration used.
After having the septic tank pumped and cleaned (or the drywell opened and inspected) and having cleaned the filter the first time,
follow the septic filter manufacturer's recommendation for cleaning frequency.
If you cannot find the manufacturer's septic or graywater filter cleaning recommendations or if you don't know
your wastewater usage level, try checking the filter again in six months. If there is no significant clogging, check it again in another six months.
Following this procedure you can determine, based on your own building's wastewater usage and flow, just how often
to clean the filter.
We recommend that you establish a regular filter inspection and cleaning schedule. If you've purchased a home
that uses one of these filters and have not already done so, schedule a septic tank pumpout and cleaning
and inspect and clean the filter at the same time.
Septic filter monitors are available from some effluent filter manufacturers to help determine when it's necessary
to clean the filter.
A great time to clean the septic system filter is immediately after the septic tank has been pumped. The empty
septic tank means that when you remove the septic filter for cleaning, no sewage will bypass it and flow into
and clog the drainfield.
Most septic filters and graywater filters will need to be inspected and cleaned more often than the septic tank
is pumped out. (Most drywells are not pumped or emptied during servicing.) Just above we discussed how to come up
with a schedule for filter cleaning.
The access cover is opened, the septic filter itself is removed and washed, typically by spraying it with a hose.
Avoid getting overspray on anyone as it is not sanitary. Replace the filter and wash your hands.
How to avoid damaging a drainfield when cleaning the septic filter
Temporarily stop running water in the building served by the septic tank during the septic filter inspection
and cleaning process. By avoiding sending wastewater into the tank during this interval, you're avoiding pushing
sewage out into the drainfield during the time that the filter has been removed for cleaning.
Check the sewage level in the septic tank: If the septic tank is opened at the access port to inspect and clean the septic filter,
before removing the filter cartridge or screen check the level of sewage in the septic tank.
If the tank wastewater level (floating scum, effluent, sludge) is abnormally high that indicates a
system blockage (maybe a clogged filter).
Do not remove the filter if the tank level is abnormally high since doing so will flush extra sewage, solids,
floating scum, grease, into the drainfield, potentially clogging it or shortening its life. If the tank level
is abnormally high (flowing over the inlet or outlet baffle or if the tank is filled to the very top) it would be
better to have the tank pumped before removing and cleaning the filter. If even after these steps are taken (septic
tank pumping and septic filter cleaning) the tank level returns to an abnormal level, there is a further blockage
in the septic system, in the distribution piping, distribution box, or drainfield, and further investigation is
How to monitor septic or graywater filters for clogging
Septic Filter Installation: make sure the septic or graywater filter is easily accessible
Septic filters are placed either in the septic tank at the outlet tee or in a separate chamber outside of and close to
the septic tank. Graywater filters may be placed at the inlet to a drywell or graywater disposal system.
If the cover at the septic filter or graywater filter is not easily accessible, excavate to expose it and install
any necessary surrounding riser and ground-level cover. In other words, make the task as easy as possible so that the
septic or gray water filter inspection and cleaning process is painless and will be done on time. These steps
will more than pay for themselves in keeping the septic system working and maximizing the life of the drainfield.
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The New Create an Oasis With Greywater, Art Ludwig; Buy New: $14.25. Ludwig is one of the most thoughtful, prolific, and sometimes controversial writers on gray water systems and alternative designs. We recommend his book as clear, easy-to-understand writing aimed at property owners who want or need to consider a graywater installation to conserve water, recycle water, reduce water use, or to reduce the load on their septic system. This is the latest edition of this Art Ludwig's greywater design book classic.
Builder's Greywater Guide, Art Ludwig; Buy New: $10.17. Installation of Greywater Systems in New Construction & Remodeling; A Supplement to the Book "Create an Oasis With Greywater" (Paperback).
Quoting a review from Amazon: I recommend that you get the 3 companion books on greywater treatment "Create an Oasis", "Branched Drain Greywater Systems" and "Builder's Greywater Guide". The information in these volumes will keep most of us far more informed than most of the regulators, the system builders, and the experts-in-theory. These volumes are real-world gems.
Art Ludwig has cut to the core of wastewater issues. He's obviously done all of his homework, mulled-over the variables, and come up with a common sense, economically reasonable, environmentally responsible approach to wastewater. I expect to save money that I would have spent on a post-septic tank, aerobic unit that would seemingly have been ecologically responsible; but because of the technological overkill, ultimately that system would have defeated my altruistic environmental concerns.
... These books talk the talk and walk the walk better than anything else that I've seen. Buy a set for yourself, a set for your neighbors, and a set for the regulators.
Branched Drain Greywater Systems [superseded by "The New Create an Oasis with Greywater"], Art Ludwig. If you already have this book but are in the process of installing new gray water systems you should take a look at the newer
edition listed first above in this section of our Greywater book recommendations.
You may prefer the newest edition, but there is great information in this older version, perhaps all you need, and these copies are
sold at very low prices - an aid to people of limited means.
Rainwater Catchment Systems for Domestic Supply: Design, Construction and Implementation,
Erik Nissen-Petersen, John Gould. (Mr. Ludwig, while much appreciated, is not the only author providing really useful design guides for graywater systems--DF)
Quoting from an Amazon review: This book reviews the art of roof and ground catchment systems for rainwater. The water collected can be used for household or other purposes. The designs are aimed for individuals with limited access to electricity and/or civic water utilities. The text includes drawings, photographs and step-by-step instructions.
One might say the book is really written for the 'aid worker' since it also considers ethnic and gender issues that would be 'obvious' to the future owners of the the systems.
Guidelines on rainwater catchment systems for Hawaii, (CTAHR resource management publication)
Patricia S. H Macomber. This more technical document may be especially helpful for rainwater collection and recycling systems for climates
where there is heavy rainfall such as demonstrated for Hawaii.
Design for Water: Rainwater Harvesting, Stormwater Catchment, and Alternate Water Reuse, Heather Kinkade-Levario. Quoting from Amazon's review: Design for Water is an accessible and clearly written guide to alternate water collection, with a focus on rainwater harvesting in the urban environment. The book:
Outlines the process of water collection from multiple sources-landscape, residential, commercial, industrial, school, park, and municipal systems
Provides numerous case studies, Details the assembly and actual application of equipment, Includes specific details, schematics, and references.
All aspects of rainwater harvesting are outlined, including passive and active system setup, storage, storm water reuse, distribution, purification, analysis, and filtration. There is even a section on rainwater harvesting for wildlife.
In addition to rainwater, there are several affordable and accessible alternate sources, including cooling tower bleed-off water, air conditioning condensate, gray water, and fog collection. Design for Water is geared to providing those making development decisions and guidelines with the information they need to set up passive harvesting techniques. The book will especially appeal to engineers, landscape architects, municipal decision-makers, developers, and landowners.
Heather Kinkade-Levario is a land-use planner in Arizona and the author of the award-winning Forgotten Rain. She is president of Forgotten Rain L.L.C., a rainwater harvesting and stormwater reuse company.
The Toilet Papers: Designs to Recycle Human Waste and Water : Dry Toilets, Greywater Systems and Urban Sewage (Paperback) Sim Van Der Ryn, Wendell Berry; Quoting from an Amazon review: With a title like "Toilet Papers" and from a distinguished eco-architect like Sim Van der Ryn, I needed no intro or review to buy a copy of this little, but well researched historical over-view of effluent mitigation and current eco-friendly toilet design.
This book is filled with good line drawings and photographs to depict everything from the historical perspective to the current dry toilets and their construction..
Quality issues in harvested rainwater in arid and semi-arid Loess Plateau of northern China,
K. Zhu, L. Zhang, W. Hart, M. Liu, H. Chen (out of print, find by search and deferred order).
Amazon's description may be helpful: Loess soils cover vast areas in the arid and semi-arid regions of northern China. Due to the lack of reliable surface water and ground-water, rainwater harvesting has played a prominent role in farmers' domestic usage and agricultural irrigation. An economical and valid type of water storage cistern with optimum design of components has been introduced to rural areas in the Loess Plateau. Different collection alternatives showed apparent variations in rainwater quality. By using different catchments, such as mortar roofs and cement-paved courtyards, compacted land or road surfaces, rainwater can be effectively collected for storage in cisterns. This study focused mainly on the quality of rainwater harvested from the different catchment systems and stored for different periods of time. By analysis of the water samples stored in these cisterns, it was evident that rainwater quality could be improved significantly by self-purification during the storage. With emphasis on rainwater quality affected by the
different catchment systems, it was found that the measured inorganic compounds in the rainwater harvested from roof-yard catchment systems generally matched the WHO standards for drinking water, while the concentrations of some inorganic compounds in the rainwater collected from land and road surfaces appeared to be higher than the guideline values for drinking water, but generally not beyond the maximum permissible concentrations. However, Fecal Coliform, which is an important bacteriological parameter for the three catchment systems, exceeded the limits of drinking water to a greater extend. Trace amounts of 55 organic pollutants were identified, including aliphatic hydrocarbons, aromatic compounds and phthalate esters, etc. The analytical results indicated that roof-yard catchments that included the ''first flush'' usually provided safe drinking water with low organic contents, even for rainwater collected immediately after rainfall. In contrast, rainwater harvested from road surfaces had poor quality
with respect to the organic constituents, regardless of stored time.
City eying home water-recycling technology; uses bath and washer water for irrigation., (ReWater Systems' equipment for greywater irrigation):
This is an article from: San Diego Business Journal [HTML] (Digital) available online in digital format. I have not (yet) reviewed it -- DF
US EPA Onsite Wastewater Treatment Systems Manual [online copy, free] Top Reference: US EPA's Design Manual for Onsite Wastewater Treatment and Disposal, 1980, available from the US EPA, the US GPO Superintendent of Documents (Pueblo CO), and from the National Small Flows Clearinghouse. Original source http://www.epa.gov/ORD/NRMRL/Pubs/625R00008/625R00008.htm Onsite wastewater treatment and disposal systems,
Richard J Otis, published by the US EPA. Although it's more than 20 years old, this book remains a useful reference for septic system designers.
U.S. Environmental Protection Agency, Office of Water Program Operations; Office of Research and Development, Municipal Environmental Research Laboratory; (1980)
"International Private Sewage Disposal Code," 1995, BOCA-708-799-2300, ICBO-310-699-0541, SBCCI 205-591-1853, available from those code associations.
"Manual of Policy, Procedures, and Guidelines for Onsite Sewage Systems," Ontario Reg. 374/81, Part VII of the Environmental
Protection Act (Canada), ISBN 0-7743-7303-2, Ministry of the Environment,135 St. Clair Ave. West, Toronto Ontario M4V 1P5 Canada $24. CDN.
Manual of Septic Tank Practice, US Public Health Service's 1959.
US EPA Onsite Wastewater Treatment Systems Manual Top Reference: US EPA's Design Manual for Onsite Wastewater Treatment and Disposal, 1980, available from the US EPA, the US GPO Superintendent of Documents (Pueblo CO), and from the National Small Flows Clearinghouse. Original source http://www.epa.gov/ORD/NRMRL/Pubs/625R00008/625R00008.htm
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 using this reference on 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.
Carson Dunlop, Associates, Toronto, have provided us with (and we recommend) Carson Dunlop Weldon & Associates' Technical Reference Guide to manufacturer's model and serial number information for heating and cooling equipment
Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on any number of copies of the Technical Reference Guide purchased as a single order. Just enter INSPECTATRG in the order payment page "Promo/Redemption" space.
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.
Onsite Wastewater Disposal, R. J. Perkins;
Quoting from Amazon: This practical book, co-published with the National Environmental Health Association,
describes the step-by-step procedures needed to avoid common pitfalls in septic system technology.
Valuable in matching the septic system to the site-specific conditions, this useful book will help you install a reliable system in
both suitable and difficult environments. Septic tank installers, planners, state and local regulators, civil and sanitary engineers,
consulting engineers, architects, homeowners, academics, and land developers will find this publication valuable.
Onsite Wastewater Treatment Systems, Bennette D. Burks, Mary Margaret Minnis, Hogarth House 1994 - one of the best septic system books around, suffering a bit from small fonts and a weak index. While it contains some material more technical than needed by homeowners, Burks/Minnis book on onsite wastewater treatment systems a very useful reference for both property owners and septic system designers.
Septic Tank/Soil-Absorption Systems: How to Operate & Maintain [ copy on file as /septic/Septic_Operation_USDA.pdf ] - , Equipment Tips, U.S. Department of Agriculture, 8271 1302, 7100 Engineering, 2300 Recreation, September 1982, web search 08/28/2010, original source: http://www.fs.fed.us/t-d/pubs/pdfimage/82711302.pdf
Septic System Owner's Manual, Lloyd Kahn, Blair Allen, Julie Jones, Shelter Publications, 2000 $14.95 U.S. - easy to understand, well illustrated, one of the best practical references around on septic design basics including some advanced systems; a little short on safety and maintenance. Both new and used (low priced copies are available, and we think the authors are working on an updated edition--DF.
Quoting from one of several Amazon reviews: The basics of septic systems, from underground systems and failures to what the owner can do to promote and maintain a healthy system, is revealed in an excellent guide essential for any who reside on a septic system. Rural residents receive a primer on not only the basics; but how to conduct period inspections and what to do when things go wrong. History also figures into the fine coverage.
Water Wells and Septic Systems Handbook, R. Dodge Woodson. This book is in the upper price range, but is worth the cost for serious septic installers and designers.
Quoting Amazon: Each year, thousands upon thousands of Americans install water wells and septic systems on their properties. But with a maze of codes governing their use along with a host of design requirements that ensure their functionality where can someone turn for comprehensive, one-stop guidance? Enter the Water Wells and Septic Systems Handbook from McGraw-Hill.
Written in language any property owner can understand yet detailed enough for professionals and technical students this easy-to-use volume delivers the latest techniques and code requirements for designing, building, rehabilitating, and maintaining private water wells and septic systems. Bolstered by a wealth of informative charts, tables, and illustrations, this book delivers:
* Current construction, maintenance, and repair methods
* New International Private Sewage Disposal Code
* Up-to-date standards from the American Water Works Association
Wells and Septic Systems, Alth, Max and Charlet, Rev. by S. Blackwell Duncan, $ 18.95; Tab Books 1992. We have found this text very useful for conventional well and septic systems design and maintenance --DF.
Quoting an Amazon description:Here's all the information you need to build a well or septic system yourself - and save a lot of time, money, and frustration. S. Blackwell Duncan has thoroughly revised and updated this second edition of Wells and Septic Systems to conform to current codes and requirements. He also has expanded this national bestseller to include new material on well and septic installation, water storage and distribution, water treatment, ecological considerations, and septic systems for problem building sites.