interpreting a soil report for onsite sewage treatment
DESCRIPTION
This presentation covers things a designer or regulator should know when interpreting a site and soil evaluation for onsite sewage treatment. I gave this presentation at the Northwest Ohio Environmental Health Association Fall Conference on October 21, 2011. I hope to add audio in the near future.TRANSCRIPT
WHAT DOES THIS MEAN??
WHAT DOES THIS MEAN??
http://www.mlmrecruitingonline.com/wp-content/uploads/2009/04/confused-man.jpg
http://www.flickr.com/photos/sterlic/2835194472/sizes/l/in/photostream/
LET’S BOIL IT DOWN TO WHAT WE REALLY
NEED TO KNOW
Will water move through the soil??
Will the soil remove contaminants from the water??
Basic Types of Soil Structure
• Courtesy of NASA (www.nasa.gov) and the Soil Science Education Home Page (soil.gsfc.nasa.gov)
Granular Blocky Prismatic
Platy Massive
C
B
E
AGranular
Platy
Blocky
Massive
Grade (Structure Development)
Strong- Units are distinct in place (undisturbed) and separate cleanly when disturbed.
Moderate- Units are well-formed and evident in place or in a hand sample
Weak- Units are barely observable in place or in a hand sample
Structureless- No discrete units observable in place or in a hand sample
Clay
Silty Clay
Silty Clay Loam
Clay Loam
Sandy Clay
Sandy Clay Loam
LoamSilt Loam
SiltSandy Loam
Sand
Percent Clay
Percent Silt
Percent Sand
FineMediumCoarse
Loamy Sand
Soil TextureTexture Triangle
Comparison of Coarse Textured and Fine Textured Soils
Coarse Textured Soil
Less porespace but more macropores
Fine Textured Soil
More total porespace
Texture and Pore Space
Describing the Soil
Understanding the Description
Observe Details, Avoid Surprises
http://www.flickr.com/photos/33778545@N07/4053418477/sizes/m/in/photostream/
Lack of Sufficient Soil Structure
Lack of Sufficient Soil Structure
Lack of Sufficient Soil Structure
Evidence of Compaction
Evidence of Compaction
http://www.omafra.gov.on.ca/english/crops/pub811/8soilresource.htm
Slickensides (Pressure Faces)
Slickensides (Pressure Faces)
Highly Permeable Material
Highly Permeable Material
Disturbed Site
Disturbed Site
http://www.flickr.com/photos/fortgirl/3513360141/in/pool-17765913@N00/
Redoxymorphic Features
redox concentrations Zones of apparent accumulation of Fe-Mn oxides in soils.
redox depletions Zones of low chroma (2 or less) where Fe-Mn oxides alone or both Fe-Mn oxides and clay have been stripped out of the soil. (used to define aquic conditions)
aquic A mostly reducing soil moisture regime nearly free of dissolved oxygen due to saturation by groundwater or its capillary fringe and occurring at periods when the soil temperature at 50 cm below the surface is >5°C.
Redoxymorphic Features
http://www.flickr.com/photos/soilrocks/317241887/in/set-72157594384192229/
Redoxymorphic Features
Putting it all together…
Here…
To here!
Can take us from……
Soil Structure
Soil Texture
Will water move through the soil?
Will it move through the soil quickly enough to disperse?
Will water move through the soil too quickly to receive adequate treatment?
Tyler Loading Rate Table
Redoxymorphic Features
Additional Observations
Is the soil periodically saturated?
Is there evidence of site disturbance that would affect water movement?
Is there evidence of a condition that would present a health hazard?
ResourcesGlossary of Soil Science Terms
https://www.soils.org/publications/soils-glossary
ResourcesSoil and Site Evaluation for Onsite Wastewater Treatment
OSU Extension Bulletin 905 http://ohioline.osu.edu/b905/index.html
ResourcesUSDA/NRCS Field Book for Describing and Sampling Soils, Version 2.0
ftp://ftp-fc.sc.egov.usda.gov/NSSC/Field_Book/FieldBookVer2.pdf
ResourcesWeb Soil Survey
http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx
Resources
Ohio Department of Health Sewage Treatment System Program
Site and Soil Evaluation for Sewage Treatment and Dispersal INSTRUCTIONS
http://www.odh.ohio.gov/odhPrograms/eh/sewage/sewrules.aspx
Jason Menchhofer, R.S.Van Wert County Health Department
419-238-0808, ext. [email protected]
Find this presentation online at:http://www.slideshare.net/jmenchhofer
THANK YOU