8,255
edits
Changes
Jump to navigation
Jump to search
no edit summary
Line 9:
Line 9:
#Where the seasonal high groundwater level comes within 1 m below the bottom of the proposed BMP,<br>Or in areas where increased infiltration will result in elevated groundwater levels, which can be demonstrated to damage critical utilities or private property,+#Over swelling clays or unstable sub-soils,+
===Constraints===
===Constraints===
Infiltration practices are not recommended:
Infiltration practices are not recommended:
−#Where the bedrock is within 1 m below the bottom of the proposed BMP,
+#over swelling clays or unstable sub-soils,
−#over contaminated soils or sites with high risk of contamination from onsite activities,
−#in flood prone areas where the wastewater system is sensitive to groundwater conditions causing sewer backups, and where LID BMPs have been found to be ineffective,
−#Over contaminated soils or sites with high risk of contamination from onsite activities,
+#in areas where the ecology and natural hydrology are dependent upon surface water,
−#In flood prone areas where the wastewater system is sensitive to groundwater conditions causing sewer backups, and where LID BMPs have been found to be ineffective,
+#in areas where increased infiltration will result in elevated groundwater levels, which can be demonstrated to damage critical utilities or private property, or
−#In areas where the ecology and natural hydrology are dependent upon surface water,
+#where prohibitions and/or restrictions exist per approved Source Protection Plans (see MOECC guidance).
−#Where prohibitions and/or restrictions exist per approved Source Protection Plans (see MOECC guidance).
+Infiltration facilities should be designed with drainage modifications where:
+#the underlying bedrock is within 1 m below the bottom of the proposed BMP, or
+#the seasonal high groundwater level comes within 1 m below the bottom of the proposed BMP.
===Designing within constraints===
===Designing within constraints===
{{TextBox|1= Infiltration can still be optimized over 'tight' soils with infiltration rates ≤ 15 mm/hr:
{{TextBox|1= Infiltration can still be optimized over 'tight' soils with infiltration rates ≤ 15 mm/hr: