Situations where infiltration is prohibited or not recommended Situations where infiltration is prohibited or not recommended

Summary of situations where infiltration of stormwater runoff is prohibited or not recommended.
Link to this table

Condition	Prohibited	Not recommended	Not recommended unless conditions are met1
Local rule or ordinance prohibits infiltration	X
BMP is < 100 feet from drinking well in sensitive aquifer3	X
BMP is < 50 feet from drinking well in a non-sensitive aquifer3	X
BMP receives discharges from vehicle fueling and maintenance areas	X
There is less than 3 of separation to bedrock or saturated soil	if CGP applies2	X
BMP receives discharges from certain industrial facilities4	if CGP applies
BMP is in areas where high levels of contaminants in soil or groundwater will be mobilized by the infiltrating stormwater	if CGP applies		X
BMP is located in D soils	if CGP applies		X
BMP is 1,000 feet up-gradient or 100 feet down-gradient of active karst	if CGP applies	X
BMP is located within an Emergency Response Area in a DWSMA exhibiting high or very high vulnerability	if CGP applies	X
BMP is located within an Emergency Response Area (ERA) in a DWSMA exhibiting moderate vulnerability, or outside an ERA in a DWSMA exhibiting high or very high vulnerability	if CGP applies, unless a higher engineering review indicates infiltration is acceptable	X
BMP is located in soils with infiltration rate > 8.3 in/hr	if CGP applies		X
BMP is located within 1 year travel time of drinking supply well			X
BMP located within 10 feet of building or structure			X
BMP located within 35 feet of a septic system			X
BMP located less than 200 feet from crest of slope that exceeds 20%		X
BMP receives discharges from a confirmed stormwater hotspot			X
A groundwater mound formed beneath the BMP during infiltration extends into the BMP		X

¹see discussion for conditions under which infiltration is acceptable.
²CGP = Construction Stormwater General Permit
³See Minnesota Rules Chapter 4725
⁴To determine if infiltration is allowed for a specific industrial sector or subsector, go to the list of sectors, select the sector of interest, and review section 8 for that sector (Use of Infiltration Devices and/or Industrial Stormwater Ponds for Stormwater Treatment and Disposal)