Differences

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--- oil_and_grease_control [2022/05/11 10:31] – admin
+++ oil_and_grease_control [2023/06/15 14:29] (current) – admin
@@ Line 58: / Line 58: @@
   *Replacement of rock may be difficult
-The trench needs to have the volume to treat the first half inch of runoff, either through total void space or through hydrologic modeling. The trench must also have a way to draw down between storms, typically with an underdrain. Because this trench does not have pretreatment, it is assumed to be clogged and may not take credit for infiltration.
+The trench needs to have the volume to treat the first half inch of runoff, either through total void space or through hydrologic modeling. The trench must also have a way to draw down between storms, typically with an underdrain, and be lined with geotextile fabric to prevent soil migration. Because this trench does not have pretreatment, it is assumed to be clogged and may not take credit for infiltration.
-The trench must be inspected regularly to ensure that the device is functioning properly and rock replaced when it becomes ineffective. The rock will become blacker and less effective as it gets coated with oil and grease.
+The trench must be inspected regularly to ensure that it's functioning properly. Replace the rock when it becomes coated with oil or grease (i.e. black-colored) or if it becomes filled with sediment.