How to Spot Unexpected or Odd Septic Drainfield Locations
How to find the septic leachfield or drainfield when it is in an unusual or unexpected location. This article series and our accompanying septic system location videos explains how to find the leach field or drainfield portion of a
septic system. We include sketches and photos that help you learn what to look for, and we
describe several methods useful for finding buried drainfield components. (Septic drain fields are also called soil absorption systems or seepage beds.)
In the page top photo you can see septic effluent running across a rocky surface during our septic loading test. Actually effluent was running across this rock before we began our septic test, but our dye succeed in proving that the wet area was indeed coming from a failed septic system. A conventional tank and drainfield could not work in this location.
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Surprising Septic System Leachfield Locations
Drainfields may be located very distant from the building and or septic tank
Remember that septic system components can be at an "illogical" or "unlikely" location
since people often make expedient or otherwise bad design choices, or may have had no
We've found drainfields that were quite remote from the building and from the
septic tank, more than 200' away (downhill).
The reason this is abnormal is that it is
expensive and trouble to dig great distances and there must either be proper slope
(elevation change) between the tank and drainfield, or a pumping system is needed.
So normally the septic contractor will not put a septic system component farther
away from the building or the tank than is necessary.
But rocky sites, steeps slopes,
ponds, or other site features may mean that the tank or drainfield are located
surprisingly far from the building they serve.
Septic Soakaway beds, Leachfields, or Drainfields may be located off of the property they serve and even across a road or highway
We've found leaching beds that were located
across a public highway from the house and septic tank. We've found leaching beds that
were not on the owner's property at all.
An illegal septic system "drainfield" may turn out to be emptying deliberately into a nearby stream or lake
Especially at older, unsupervised, or remote rural properties, the temptation to
simply route effluent leaving the septic tank to a stream, lake, pond is sometimes
overwhelming (though unsanitary and illegal).
This is particularly true at sites
where the soils into which one would have to put the drainfield are rocky, wet,
or where the drainfield has previously failed.
In the photo at left you can see that this septic tank is less than ten feet from a lake.
For example, at properties
along Wappingers Creek in Dutchess County, NY, many of the homes
located their drainfields downhill from the house and too close to the creek.
In times of spring rains the creek floods and floods the drainfield area. These are not working
drainfields and are unsanitary.
At a home inspection at one of these properties we found
that the previous owner had installed a straight pipe from the end of his failed
drainfield right into the creek. Our septic loading and dye test was turning Wappingers
Creek a reddish pink!
There may be no septic system drainfield at all at some properties. Here is an example:
We've also found that there was in fact no leaching
bed at all - simply a short perforated pipe into the ground next to a septic tank, or worse,
an illegal pipe to a storm drain, creek, or to the surface of a hillside.
This farm property, which we were inspecting outside Frankfort, Germany in 1968, had toilets but no working drainfield at all.
Also see How to Find the Septic Tank. More videos on septic system location & maintenance are at SEPTIC VIDEOS.
Continue reading at UNLIKELY DRAINFIELD LOCATIONS or select a topic from the More Reading links or topic ARTICLE INDEX shown below.
or see SEPTIC COMPONENT LOCATIONS for help finding the septic tank, distribution box, drainfield, soakaway bed
Suggested citation for this web page
SURPRISING DRAINFIELD LOCATIONS at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.
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Technical Reviewers & References
Publisher's Google+ Page by Daniel Friedman
Click to Show or Hide Citations & References
- New York State Department of Health, "Appendix 75-A Wastewater Treatment Standards - Individual Household Systems", [PDF] New York State Department of Health, 3 February 2010, retrieved 3/1/2010, original source: https://www.health.ny.gov/regulations/nycrr/title_10/part_75/appendix_75-a.htm
- Percolation Testing Manual, CNMI Division of Environmental Quality, Gualo Rai, Saipan provides an excellent English Language manual guide for soil percolation testing. Original source: www.deq.gov.mp/artdoc/Sec6art108ID255.pdf
- Soil Test Pit Preparation, fact sheet, Oregon DEQ Department of Environmental Quality, original source www.deq.state.or.us/wq/pubs/factsheets/onsite/testpitprep.pdf The Oregon DEQ onsite water quality program can be contacted at 811 South Ave, Portland OR 97204, 800-452-4011 or see http://www.oregon.gov/DEQ/
- Thanks to reader Michael Roth
for technical link editing 6/29/09.
- 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.
- How Big Should the Leach Field Be? - table of soil percolation rate vs. field size
- Septic System Drainfield Absorption System Biomat Formation - what leads to drain field clogging and expensive drainfield repairs
- Table of Required Septic & Well Clearances: Distances Between Septic System & Wells, Streams, Trees, etc.
- Pennsylvania State Fact Sheets relating to domestic wastewater treatment systems include
- Pennsylvania State Wastewater Treatment Fact Sheet SW-161, Septic System Failure: Diagnosis and Treatment
- Pennsylvania State Wastewater Treatment Fact Sheet SW-162, The Soil Media and the Percolation Test
- Pennsylvania State Wastewater Treatment Fact Sheet SW-l64, Mound Systems for Wastewater Treatment
- Pennsylvania State Wastewater Treatment Fact Sheet SW-165, Septic Tank-Soil Absorption Systems
- Document Sources used for this web page include but are not limited to: Agricultural Fact Sheet #SW-161 "Septic Tank Pumping," by Paul D. Robillard and
Kelli S. Martin. Penn State College of Agriculture - Cooperative Extension, edited and annotated by
Dan Friedman (Thanks: to Bob Mackey for proofreading the original source material.
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
- 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.