Updates from October 2021

(Source: E&S Resources Library on PADEP Website)

DEP PCSM Spreadsheet was updated to Version 1.9 as of October 2021:

"1) Modified dropdown list for Infiltration Period (Volume Worksheet, Structural BMP Volume Credits table) to eliminate hours 1-11 (i.e., the minimum Infiltration Period must be 12 hours).  

2) Updated median outflow concentrations (MOCs) for structural BMPs based on the latest analysis of literature data."

As a reminder, the DEP PCSM Spreadsheet Instructions states: "In general, DEP/CCD will accept older versions of the spreadsheet no more than 6 months following the revision date of the spreadsheet. DEP/CCD also reserves the right to request completion of the latest version of the spreadsheet for any project."

Here is an independent analysis of how the MOCs changed. The lower the MOC, the better the water quality treatment. Therefore, if the MOC was reduced, the new value is green, and if the MOC was increased, the new value is red. 

BMP	TSS MOC (mg/L)	TP MOC (mg/L)	TN MOC (mg/L)
Porous Pavement w/Infiltration Bed	26 22	0.11 0.1	1.19 2.38
Infiltration Basin	10	0.24	1.04 0.96
Infiltration Bed	24.3 22	0.19 0.1	1.19 2.38
Infiltration Trench	24.3 22	0.19 0.1	1.19 2.38
Rain Garden / Bioretention	10	0.24	1.04 0.96
Dry Well / Seepage Pit	24.3 22	0.19 0.1	1.19 2.38
Constructed Filter	9	0.09	1.05
Vegetated Swale	24 13.7	0.2 0.18	0.85 0.63
Vegetated Filter Strip	19 23	0.17 0.23	1.13 1.27
Infiltration Berm & Retentive Grading	24 10	0.2 0.24	0.85 0.96
Vegetated Roof	19 23	0.17 0.23	1.13 1.27
Capture and Reuse	N/A	N/A	N/A
Constructed Wetland	12 14	0.1 0.12	1.31 1.37
Wet Pond / Retention Basin	11.7 12	0.09 0.12	1.2
Dry Extended Detention Basin	24.3 22	0.19	1.19 1.22
Water Quality Filters & Hydrodynamic Devices	9 39	0.09 0.18	1.05 2.21
Floodplain Restoration	10 24	0.24 0.18	1.04 1.45
Soil Amendment	19 23	0.17 0.23	1.13 1.27
Riparian Buffer	10 23	0.24 0.23	1.04 1.27

DEP PCSM Spreadsheet Instructions was updated as of October 18, 2021:

"Modified the description for Infiltration Period (Volume Worksheet, Structural BMP Volume Credits table) and NOTE 33 to reflect a change in the PCSM Spreadsheet that a minimum of 12 hours must be selected to represent infiltration that is occurring during a storm event. In addition, the PCSM Spreadsheet has been modified to include updates to Median Outflow Concentrations (MOCs) for structural BMPs based on the latest analysis of literature data."

Alternative E&S and PCSM BMPs was updated to Version 2.1 on October 26, 2021:

"Added Trenchless Curved Silt Fence as an approved alternative E&S BMP"