SW5240603_Design Calculations_20240911 (3)

Project Information Complete this sheet if required by your reviewing authority.
Contact them for any questions. Grey boxes/text are optional.
SNAPv4.2.0 LOCATION
Project Name(optional): Eaddy Building Addition Parcel ID(optional):
Submission Date(optional): date Nutrient Management Watershed: menu
Local Jurisdiction/Reviewing Agency: State/Federal menu Subwatershed: Neuse-Upper menu
Project Latitude Coordinates(optional): N Phosphorus Delivery Zone: Neuse- Upper 03020201 menu
Project Longitude Coordinates(optional): W Nitrogen Delivery Zone: Neuse- Upper 03020201 menu
-
PROJECT DETAILS
Development Land Use Type: Institutional menu Disturbed Area: 0 ft2
Part of Common Development Plan? .no yin Project Activity: New Development menu
Designated Downtown Area? no yin Project Drains to SA Waters? no yin
Public Linear Road/Sidewalk Project? .no yin Pre-Project Land Use: developed menu
Project Owner Type: State non-NCDOT menu Project Description(optional):
STORMWATER DETAILS
(Falls ONLY)Onsite Reduction%Req. % Project Uses LID/Runoff Volume Match? no yin
Existing BUA/Development Onsite? yes y/n Local Gov't nutrient req's same as State? yes y/n
Local Gov't cutoff date for Existing BUA: 05/01/2023 date Project Drains to Regional SCM? no y/n
Nitrogen Export Rate Target: 3.60 lb/ac/yr Total Nitrogen Offset Credits Needed: lb/yr
Phosphorus Export Rate Target: 1000.00 lb/ac/yr Total Phosphorus Offset Credits Needed: lb/yr

SNAP v4.2.0
Project Area and Offsite Land Cover Characteristics Precipitation Neuse
Station:
Copy ' Paste VALUES ONLY for Best Results Click here to scroll down to error messages on this sheet.
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PROJECT AREA LAND COVERS TN EMC (mg/L) TP EMC (mg/L) Pre-Project Area (ft2) Post-Project Area (ft2) Change pre-to-post(ft2)
1
Roof 1.18 0.11 0
Roadway 1.64 0.34 0
Parking/Driveway/Sidewalk 1.42 0.18 0
Protected Forest 0.97 0.03 0
Managed Pervious/Landscaping 2.48 1.07 21,990,479 21,990,479 0
Offsite or Existing Roof 1.18 0.11 568,337 568,337 0
Offsite or Existing Roadway 1.64 0.34 0
Offsite or Existing Parking/Driveway/Sidevin 1.42 0.18 1,575,195 1,575,195 0
Offsite Protected Forest 0.97 0.03 0
Offsite Managed Pervious 2.48 1.07 0
CUSTOM LAND COVER 1 0
CUSTOM LAND COVER 2 0
CUSTOM LAND COVER 3 0
LAND TAKEN UP BY SCM 1.18 0.11 0
Total (Regulated & UnReg)Area 24,134,011.00 24,134,011.00
Project (Regulated)Area 21,990,479.00 21,990,479.00

Nutrient Export Summary
Landcover Et SCM Data Review
Errors/Advisories
Avg Annual precip(in) = 45.76
Total (Regulated+
24,134,011
Unregulated)Area (ft2)=
Project(Regulated)
21,990,479
Area (ft2) =
Net BUA(Project Area 0 Net BUA indicates redevelopment or a non-
BUA only ft2)= development activity.
Custom Landcovers are
present:
no
Total Nitrogen Export Target
Scaled to Project Area (Ib/yr): 1817.39
Total Area Total Area Project Area
Project Area
(Onsite+ Post-Project Post-Project
Nutrient Export Summary (Onsite Only)
Offsite) before before
Pre-Project
Pre-Project Treatment Treatment
Area (All Landcover Types) (acres) 554.0407 504.8319 554.0407 _ 504.8319
Percent Built-Upon Area (BUA)(%) 9% 0% 9% 0%
Built-Upon Area(BUA) (sqft) 2,143,532 0 2,143,532 I 0
Annual Runoff Volume(ft3/yr) 10,762,338 3,773,566 10,762,338 3,773,566
Annual Runoff%Change 0% 0%
Total Runoff Change(cuft/yr) 0 0
Total Nitrogen EMC(mg/L) 1.75 0.95 1.75 2.48
Total Nitrogen Load Leaving Site(Ib/yr) 1,176.28 584.37 1,176.28 584.37
Total Nitrogen Loading Rate(Ib/ac/yr) 2.12 1.16 I 2.12 1.16
Total Nitrogen%Change Pre-to-Post 0% 0%
Total Nitrogen Change(Ib/yr) Pre-to-Post 0.00 0.00
Total Phosphorus EMC(mg/L) 0.48 0.41 0.48 7- 1.07
Total Phosphorus Load Leaving Site(Ib/yr) 322.58 252.13 322.58 252.13
Total Phosphorus Loading Rate(Ib/ac/yr) 0.58 0.50 0.58 0.50
Total Phosphorus%Change Pre-to-Post 0% _+ 0%
Total Phosphorus Change (Ib/yr)Pre-to-Post 0.00 0.00
SCM/Catchment Summary
1

SCM ID and Type Volume TN Reduction TP Reduction TN Out I TP Out
Reduction(%) (%) (%) (Ibs/ac/yr) (Ibs/ac/yr)
i
Catchment 1 0.00% 0.00% g 0.00% 0.00 0.00
101:NA 0.00% 0.00% 0.00% 0.00 0.00
102:NA 0.00% 0.00% 0.00% 0.00 0.00
103:NA 0.00% 0.00% 0.00% 0.00 0.00
Catchment 2 0.00% 0.00% _ 0.00% 0.00 0.00
201:NA 0.00% 0.00% 0.00% 0.00 0.00
202:NA 0.00% 0.00% _ 0.00% 0.00 0.00
203:NA 0.00% 0.00% 0.00% 0.00 0.00
Catchment 3 0.00% 0.00% 0.00% 0.00 0.00
301:NA 0.00% 0.00% 0.00% 0.00 0.00
302:NA 0.00% 0.00% 0.00% 0.00 0.00
303:NA 0.00% 0.00% 0.00% 0.00 0.00
Catchment 4 0.00% 0.00% _ 0.00% 0.00 0.00
401:NA 0.00% 0.00% 0.00% 0.00 0.00
402:NA 0.00% 0.00% _ 0.00% 0.00 0.00
403:NA 0.00% 0.00% 0.00% 0.00 0.00
Catchment 5 0.00% 0.00% 0.00% 0.00 0.00
501:NA 0.00% 0.00% 0.00% 0.00 0.00
502:NA 0.00% 0.00% 0.00% 0.00 0.00
503:NA 0.00% 0.00% 0.00% 0.00 0.00
Catchment 6 0.00% 0.00% _ 0.00% 0.00 0.00
601:NA 0.00% 0.00% 0.00% 0.00 0.00
602:NA 0.00% 0.00% _ 0.00% 0.00 0.00
603:NA 0.00% 0.00% 0.00% 0.00 0.00
1

SNAP v4.2.0
Errors/Advisories
SCM Area (ft2) = 0
SCM Treated Area (ft2) = 0
Catchment Routing: No errors
Treating Runoff from
Existing BUA or Offsite:
no
Disturbed Area (ft2) = 0
Total Phosphorus Export Target
504831.93
Scaled to Project Area (Ib/yr):
Total Area Project Area Total Area Project Area
Total Area Project Area
Post-Project Post-Project Post-Project Post-Project
Post-Project Post-Project
SCM-Treated SCM-Treated Untreated Untreated
after Treatment after Treatment
Area Only Area Only Areas Areas
554.0407 504.8319 0.0000 0.0000 554.0407 504.8319
9% I 0% 0% 0% 9% I 0%
2,143,532 0 0 0 2,143,532 _ 0
10,762,338 3,773,566 0 0 10,762,338 3,773,566
0% 0%
0 0
1.75 2.48 0.00 0.00 1.75 2.48
1,176.28 I 584.37 0.00 0.00 1,176.28 _ 584.37
2.12 I 1.16 0.00 0.00 2.12 1.16
0% 0%
0.00 I 0.00
0.48 1.07 0.00 0.00 0.48 1.07
322.58 I 252.13 0.00 0.00 322.58 252.13
0.58 0.50 0.00 0.00 0.58 0.50
0% 0%
0.00 1 0.00
1

Falls Lake ONLY: Onsite Reduction Compliance Check
Nitrogen Phosphorus
Onsite%Reduction Requirement
Export Target Scaled to Area (Ib/yr) 1,817.39 504,831.93
Export Load Post-Project Before Treatment 584.37 252.13
Total Reduction Need (Ib/yr)
Onsite Reduction Need (Ib/yr) _
Onsite Export Target(Ib/yr)
Project Area Post-Project After Treatment 584.37 252.13
1

Nutrient Management Strategy Watershed - Nutrient Offset Credit Reporting Form
SNAP v4.2.0
Please complete and submit the following information to the local government permitting your development project
to characterize it and assess the need to purchase nutrient offset credits. Contact and rule implementation
information can be found online at:
http://deq.nc.gov/about/divisions/water-resources/planning/nonpoint-source-management/nutrient-offset-information
PROJECT INFORMATION
Applicant Name:1
Project Name: Eaddy Building Addition
Project Address:
Date: (mm/dd/yyyy) Development Land Use Type: Institutional
County: Project Activity Type: New Development
Project Area(sqft): 21,990,479 Project Latitude: 0.000000
Post-Project Built-Upon Area%: 0.00% I Project Longitude: 0.000000
WATERSHED INFORMATION
Nutrient Management Watershed: 0 N Target Export Rate(Ib/ac/yr): 3.60
Subwatershed: Neuse-Upper P Target Export Rate(Ib/ac/yr): 1000.00
Nitrogen Delivery Zone: Neuse-Upper 03020201 Nitrogen Delivery Factor: 100%
Phosphorus Delivery Zone: Neuse-Upper 03020201 Phosphorus Delivery Factor: 100%
PERMANENT NUTRIENT OFFSET REQUEST
Post-Project Nitrogen Calculations -Projects with No Offsite or Built-Upon Area
(A) (B) (C) (D) (F) (G) (Where
Applicable)
TN Export TN Remaining TN Permanent Additional I Total TN
TN Untreated TN Treated TN Delivery Offsets Permanent
Load(Ib/yr) Target Load Load(lb/yr) Reduction Factor(%) Required Local Gov't Offsets to
(Ib/yr) Need(Ib/yr) (Ib/yr) Offsets(Ib/yr) Buy(Ib/yr)
584.4 1817.4 584.4 0.0 1 100.0% 0.0 0.0 I
Post-Project Phosphorus Calculations -Projects with No Offsite or Built-Upon Area
(A) (B) (C) (D) (F) (G) (Where
Applicable)
TP Export TP Remaining TP Permanent Additional I Total TP
TP Untreated TP Treated TP Delivery Offsets Permanent
Load(Ib/yr) Target Load Load(Ib/yr) Reduction Factor(%) Required Local Gov't Offsets to
(Ib/yr) Need(Ib/yr) (Ib/yr) Offsets(Ib/yr) Buy(Ib/yr)
252.1 504831.9 r 252.1 0.0 100.0% 0.0 0.0
LOCAL GOVERNMENT AUTHORIZATION
Local Government Name:I
Staff Name: Phone:
Staff Email: Date:
Local Government Authorizing Signature: