Changes

!<br>'''Follow-up and Corrective Actions'''

!<br>'''Follow-up and Corrective Actions'''

|-

|-

|'''[[Bioretention]] / [[Bioswales]] / [[Stormwater Tree Trenches]] / [[Stormwater planters]] and [[Dry swale|Dry swales]] ([[filter media]] bed surface)'''

|'''[[Bioretention]] / [[Bioswales]] / [[Stormwater Tree Trenches]] / [[Stormwater planters]] and [[Dry swale|Dry swales]]''' ([[filter media]] bed surface)  

|

|

i < 25 mm/h;

i < 25 mm/h;<br>

KS < 1 x 10-5 cm/s<br>

K_S < 1 x 10-5 cm/s<br>

<br>

<br>

i > 203 mm/h;<br>

i > 203 mm/h;<br>

KS > 0.02 cm/s  

K<sub>S</sub > 0.02 cm/s  

|

|

*When part of an Assumption inspection, issue a stop work order and contact the construction site supervisor, design professionals and property owner or project manager to determine follow-up tasks. Follow-up tasks involve scheduling FIT work to do further testing to determine the affected area and depth and decide on corrective actions.

*When part of an Assumption inspection, issue a stop work order and contact the construction site supervisor, design professionals and property owner or project manager to determine follow-up tasks. Follow-up tasks involve scheduling FIT work to do further testing to determine the affected area and depth and decide on corrective actions.

*Corrective actions may involve removal of any accumulated sediment, mulch or stone cover and plantings and tilling of the top 20 to 30 cm of filter media to eliminate surface crusting or macropores and reduce compaction. *Alternatively, removal and replacement of all or the uppermost 15 cm of filter media with material that meets design specifications may be necessary.  

*Corrective actions may involve removal of any accumulated sediment, mulch or stone cover and plantings and tilling of the top 20 to 30 cm of filter media to eliminate surface crusting or macropores and reduce compaction. *Alternatively, removal and replacement of all or the uppermost 15 cm of filter media with material that meets design specifications may be necessary.  

|-

|-

|'''Single Ring Infiltrometer''' (constant or falling head)

|'''[[Permeable pavement|Permeable pavements]]''' (pavement surface)  

|

|

*Similar to the double-ring infiltrometer, except with only one ring (See photo example - Source: Werner, 2010<ref>Werner, A. 2010. File:Single ring.JPG. Original upload December 21, 2005. Author: Soil Physics at English Wikipedia. https://commons.wikimedia.org/wiki/File:Single_ring.JPG.</ref>) Can be used to measure the vertical movement of water through a soil or permeable pavement. The standard design is a ring that is 30 cm in diameter and 20 cm tall, driven 5 cm into the soil or sealed to the surface of a permeable pavement and filled with water (Klute, 1986<ref>Klute, A. 1986. Methods of soil analysis, Part I. Physical and mineralogical methods, 2nd edition. Soil

i < 250 mm/h

 

|

|

*The Modified Philip-Dunne infiltrometer (See photo example - Source: Ahmed et al. 2011<ref>Ahmed, F., Gulliver, J.S. and Nieber, J.L. 2011. Performance of low impact development practices on stormwater pollutant load abatement. https://www.researchgate.net/publication/283326958_Performance_of_Low_Impact_Development_Practices_on_Stormwater_Pollutant_Load_Abatement</ref>) is a falling head test device made of an open ended 50 cm long clear plastic cylinder with 2 mm thick walls, a 10 cm inner diameter and graduations, inserted into a machined metal base. Unlike the Philip-Dunne permeameter, which requires digging a borehole (i.e., not a surface infiltration test method), it is inserted 5 cm into the surface of the soil without the need for removing vegetation cover. Water level measurements in the tube can be obtained using the graduations on the side of the cylinder and a stopwatch, or continuously recorded through use of a data logger and pressure transducer installed in a piezometer tube. <br>

*When part of an Assumption inspection, issue a stop work order and contact the construction site supervisor, design professionals and property owner or project manager to determine follow-up tasks. Follow-up tasks involve scheduling FIT work to do further testing to determine the affected area and decide on corrective actions.  

 

*Corrective action should first involve thoroughly sweeping and vacuuming the affected pavement area when dry in an attempt to remove sediment accumulated in the pavement joints or pore spaces. If vacuuming does not restore surface infiltration rate to an acceptable value (i.e., ≥ 250 mm/h) try manual or pressure washing means to remove surface crust and sediment from paver joints or pore spaces.  

*Measurements of soil moisture (e.g., using a handheld soil moisture probe) are needed before and after each test. Using relationships established by Ahmed and Gulliver (2011)<ref>Ahmed, F. and Gulliver, J.S. 2011. User’s manual for the MPD infiltrometer. St. Anthony Falls Laboratory, University of Minnesota, Minneapolis, MN. https://conservancy.umn.edu/bitstream/handle/11299/122987/Ahmed-Gulliver-Nieber%20%282011%29%20-%20SAFL%20PR560.pdf?sequence=1&isAllowed=y</ref>, the observed infiltration rate and initial and final soil moisture measurements are used to calculate a value for saturated hydraulic conductivity. A quicker test to perform than constant head tests. Superior to the single-ring infiltrometer falling head test as lateral flow is incorporated into the calculations.

*In extreme cases, removal of the affected portion of the surface course and bedding and reinstallation with materials that meet design specifications may be necessary.

|[[File:Modified Philip Dunne.PNG|350px]]

|-

|-

|'''Guelph Permeameter with Tension Disk''' (constant head)  

|'''[[Enhanced Swales]] / [[Vegetated filter strips]] & [[Absorbent landscapes|Soil Amendment Areas]]''' (topsoil surface)  

|

|

*The Guelph permeameter (See photo example - Source: Hoskin Scientific Ltd., 2022<ref>Hoskin Scientific Ltd. 2022. Guelph Permeameter Kit. https://www.hoskin.ca/catalog/index.php?main_page=product_info&cPath=1_59_67_3677&products_id=5082</ref>)is another test device for measuring saturated hydraulic conductivity of a soil surface when used with a tension disc attachment. The method is similar to a Tension infiltrometer, but with water being directed to the tension disc from an inner or outer Mariotte reservoir, giving it the capacity to test low and high permeability soils (Soil Moisture Equipment Corp. 1986<ref>Soil Moisture Equipment Corporation. 1986. Guelph permeameter 2800ki operating instructions. Revision 8/86. Santa Barbara, CA.)</ref>. Infiltration rates are calculated from monitoring the water level drop in the reservoir until a steady state is approached.

*When part of an Assumption inspection, issue a stop work order and contact the construction site supervisor, design professionals and property owner or project manager to determine follow-up tasks. Follow-up tasks involve scheduling FIT work to do further testing to determine the affected area and depth and decide on corrective actions.

 

*Corrective actions may involve removal of any accumulated sediment and plantings and tilling of the topsoil to between 20 and 30 cm depth to eliminate surface crusting, increase porosity and reduce compaction. If testing indicates low organic matter content, topsoil should be amended with compost prior to tilling.

*Like the Tension infiltrometer method below, tests are run with two applied tensions. Steady state infiltration rates from the two applied tensions are used to calculate a value for saturated hydraulic conductivity. Potentially requires large volume of water and significant length of time for each measurement to reach steady state.

|'''Tension Infiltrometer''' (constant or falling head)

*This test involves a porous disc of 10 or 20 cm diameter that is connected to a Marriotte bottle (water reservoir) and a bubbling tower where a negative pressure or tension is set (See photo example - Source: ICT International, n.d.<ref>ICT International. n.d. Determination of Soil Unsaturated Hydraulic Conductivity. https://www.ictinternational.com/casestudies/determination-of-soil-unsaturated-hydraulic-conductivity/</ref>). The porous disc must be placed in contact with the soil surface which usually requires removal of any vegetation and debris. In many cases it is necessary to place a thin layer of fine sand onto the soil surface to provide good contact between the disc and the soil. <br>

 

*Infiltration rates are measured based on the water level drop in the water reservoir. The steady state infiltration rate into the soil is measured for two applied water pressures. To estimate saturated hydraulic conductivity the pressures need to be slightly negative (i.e., tensions) and it is recommended that successive pressures of -5 cm and -1 cm be used (Erickson et al., 2013)<ref>Erickson, A.J., Weiss, P.T., Gulliver, J.S. 2013. Optimizing Stormwater Treatment Practices: A Handbook of Assessment and Maintenance. New York: Springer. https://experts.umn.edu/en/publications/optimizing-stormwater-treatment-practices-a-handbook-of-assessmen</ref>. The measured steady state infiltration rates are used in equations derived by Reynolds and Elrick (1991)<ref name="example2">Reynolds, W.D. and Elrick, D.E. 1991. Determination of hydraulic conductivity using a tension infiltrometer. Soil Science Society of America Journal. 55(3):633-639.  to calculate a value for saturated hydraulic conductivity. https://acsess.onlinelibrary.wiley.com/doi/abs/10.2136/sssaj1991.03615995005500030001x</ref> <br>

 

*For detailed guidance on how to perform the testing, refer to Reynolds and Elrick (1991)<ref name="example2" />. The Mini-disc Tension infiltrometer (4.5 cm porous disc) uses a falling head method developed by Zhang (1997)<ref>Zhang, R. 1997. Determination of soil sorptivity and hydraulic conductivity form the disk infiltrometer. Soil Science Society of America Journal. 61: 1024-1030. https://acsess.onlinelibrary.wiley.com/doi/abs/10.2136/sssaj1997.03615995006100040005x</ref> to estimate saturated hydraulic conductivity. It is a quicker test to perform than the constant head method but potentially more difficult to achieve adequate contact with the soil surface.

|[[File:Tension infilt data log.PNG|350px]]

|}

|}