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Line 22: + + + + + + + + + + + + + + + + + + + + + + + + + + + + + − *Surficial geology and underlying stratigraphy;+ − *Watercourses (perennial and intermittent), water bodies, wetlands and floodplains;+ − *Small headwater drainage features;+ − *Topography, slope, and drainage patterns;+ − *Existing land cover and land use;+ − *Natural heritage conservation areas; and+ − *Other man-made features or conditions that may impact design such as existing nearby structures (buildings, infrastructure, etc.).+ − A sketch plan or preliminary layout plan for the proposed development should be evaluated, including:+ + + + + + + + + + + + + + + + + + + + + + + + + + − *The preliminary grading plan and areas of cut and fill;+ − *The location and water surface elevation of all existing, and location of proposed water supply sources and wells;+ − *The location of all existing and proposed on-site wastewater (septic) systems; − *The location of other features of note such as utility rights-of-way, water and sewer lines, etc.; − *Existing data from borehole, well and geophysical testing; and − *Proposed location of development features (buildings, roads, utilities, etc.).
no edit summary
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*[[Permeameter]]
*[[Permeameter]]
*Double ring infiltrometer
*[[Double ring infiltrometer]]
*Cased borehole ([[percolation test]])
*[[Percolation test]]
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|
*[[Grain size analysis]] (Hazen)
*[[Grain size analysis]] (Hazen)
*Single ring infiltrometer
*Single ring infiltrometer
*Soil textural classification
*Soil textural classification
|}
==Becoming familiar with the different measurement practices==
STEP have produced a free online module to provide some basic information on infiltration test methods. Register [https://sustainabletechnologies.ca/events/design-infiltration-rate-e-learning-course/ '''HERE''']
==Safety correction==
The measured or calculated infiltration rate must be divided by a value between 2 and 3 before use in design<ref>Design criteria for infiltration. (2018, February 14). Minnesota Stormwater Manual, . Retrieved 00:16, March 14, 2018 from https://stormwater.pca.state.mn.us/index.php?title=Design_criteria_for_infiltration&oldid=35583.</ref>
{| class="wikitable"
|+ Selecting a safety factor
|-
! 2
! 3
|-
|Catchment < 100 m²
|Catchment > 100 m²<ref>Ballard, B. W., Wilson, S., Udale-Clarke, H., Illman, S., Scott, T., Ashley, R., & Kellagher, R. (2015). The SuDS Manual. London.</ref>
|-
|Permeameter or percolation test on site
|Double ring infiltrometer test on site, or grain size analysis used <ref>San Francisco Public Utilities Commission. (2017). Determination of Design Infiltration Rates for the Sizing of Infiltration‐based Green Infrastructure Facilities. Retrieved from http://sfwater.org/modules/showdocument.aspx?documentid=9681</ref>
|-
|Loamy or sandy soil
|Clayey soil<ref>CRC for Water Sensitive Cities. (2015). Adoption Guidelines for Stormwater Biofiltration Systems: Appendix C - Guidelines for filter media in stormwater biofiltration systems.</ref>
|}
|}
==Planning for testing==
==Planning for testing==
===Background Evaluation===
===Background Evaluation===
Prior to performing testing and developing a detailed site plan, existing site conditions should be inventoried and mapped including, but not limited to:
Prior to performing testing and developing a detailed site plan, existing site conditions should be inventoried and mapped including, but not limited to:
#Surficial geology and underlying stratigraphy;
#Watercourses (perennial and intermittent), water bodies, wetlands and floodplains;
#Small headwater drainage features;
#Topography, slope, and drainage patterns;
#Existing land cover and land use;
#Natural heritage conservation areas; and
#Other man-made features or conditions that may impact design such as existing nearby structures (buildings, infrastructure, etc.).
A sketch plan or preliminary layout plan for the proposed development should be evaluated, including:
#The preliminary grading plan and areas of cut and fill;
#The location and water surface elevation of all existing, and location of proposed water supply sources and wells;
#The location of all existing and proposed on-site wastewater (septic) systems;
#The location of other features of note such as utility rights-of-way, water and sewer lines, etc.;
#Existing data from borehole, well and geophysical testing; and
#Proposed location of development features (buildings, roads, utilities, etc.).
===Sampling===
[[File:Test_pit.jpg|thumb|Infiltration testing should be carried out at relevant stages down through the profile of a test pit.]]
The number of test pits or soil borings varies depending on site conditions and the proposed development plan. General guidelines are as follows:
{| class="wikitable"
! BMP footprint (m²)
! Test pit
! Bore hole
|-
| < 50 || 1 || 1
|-
|rowspan = 2| 50 – 900 <br> (alternative)|| 1 || 2
|-
| 2 || 0
|-
| rowspan = 2|> 900 <br> (alternative)|| 1 every 450 m² || 2 every 450 m²
|-
| 2 every 450 m² || 0
|-
| Linear || 1 every 450 m² || 1 every 50 m
|}
* Tests must be conducted within 10 m of the infiltration practice footprint area.
* Where multiple test are carried out, they should be planned equidistant and mapped accordingly.
'''The recommendations above are guidelines'''
Additional tests should be conducted if local conditions indicate significant variability in soil types, geology, water table levels, depth and type of bedrock, topography, etc. Similarly, uniform site conditions may indicate that fewer test pits are required. Excessive testing and disturbance of the site prior to construction is not recommended.<ref>Christopher B. Burke Engineering LLC. (2009). Soil Infiltration Testing Protocol SOIL INFILTRATION TESTING PROTOCOL Purpose of this Protocol Who Should Conduct Testing. Retrieved from https://www.in.gov/ocra/files/Appendix%20F%20-%20Soil%20Infiltration%20Testing%20Protocol.pdf</ref>
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[[Category:Infiltration]]