Approved Facility Types
Stormwater Management Facility Type
| Credit Given with Associated Design Approach
| Pollution Reduction
|| Flow Control
|Eco-roof & roof garden||Simplified||Simplified||NA|
|Pervious pavement||Simplified||Simplified||Simplified/Presumptive (4)|
|Infiltration Stormwater planter||Simplified (1)||Simplified||Presumptive|
|Filtration Stormwater planter||Simplified (1)||Simplified||NA|
|Swales < 15,000 sq-ft impervious area||Simplified (1)||NA||Presumptive|
|Swales > 15,000 sq-ft impervious area||Presumptive||NA||Presumptive|
|Level Spreader||Presumptive (7)||Presumptive (7)||Presumptive (7)|
|Vegetated filter strip||Simplified||NA||Simplified (5)|
|Infiltration Rain Garden||Simplified (1)||Simplified||Presumptive|
|Filtration Rain Garden||Simplified (1)||Simplified||NA|
|Sand filter||Simplified (1)||Simplified||Presumptive|
|Extended wet detention pond||Presumptive||Presumptive||NA|
|Dry detention pond||Presumptive (3)||Presumptive||NA|
|Manufactured treatment technology||Performance||NA||NA|
|Structural detention facility||NA||Presumptive||NA|
|Spill control manhole||Presumptive (2)||NA||NA|
|Soakage trench||NA (6)||Presumptive||Presumptive|
Exhibit 2-1 Notes:
(1) The Presumptive Approach may be used to downsize these Simplified Approach facilities.
(2) Spill control manholes receive credit for oil removal only; additional pollution reduction facilities will be required to meet basic water quality management.
(3) Vegetated or grassy swales must be integrated into the bottom of dry detention ponds to receive pollution reduction credit.
(4) Pervious pavements in NRCS soil types A or B meet destination requirements when designed using the SIM Form.
(5) Vegetated filter strips designed using the SIM Form may be used for destination for some small projects as outlined in Chapter 2 of the Stormwater Management Manual.
(6) Soakage trenches, having a minimum 18-inch layer of sand for filtration installed below the soakage trench and designed per "Soakage Trench" facility design requirements, may meet pollution reduction requirements.
(7) Level spreaders must include dedicated filtration buffer in the design for management credit.