SW5240603_Design Calculations_20240911 (2)

North Section SNAP Tool Project Info
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): 35.814000 N Phosphorus Delivery Zone: Neuse- Upper 03020201 menu
Project Longitude Coordinates(optional): -78.711000 W Nitrogen Delivery Zone: Neuse- Upper 03020201 menu
PROJECT DETAILS
Development Land Use Type: Institutional menu Disturbed Area: 33,976 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 yin Local Gov't nutrient req's same as State? yes yin
Local Gov't cutoff date for Existing BUA: 05/01/2023 date Project Drains to Regional SCM? no yin
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

Land Cover Characteristics
SNAP v4.2.0
Project Area and Offsite Land Cover Characteristics Precipitation Raleigh
Station:
Copy ' Paste VALUES ONLY for Best Results Click here to scroll down to error messages on this sheet.
PROJECT AREA LAND COVERS ITN EMC (mg/L) TP EMC (mg/L) Pre-Project Area (ft2) Post-Project Area (ft2) Change pre-to-post(ft2)
Roof 1.18 0.11 — 4,993 4,993
Roadway 1.64 0.34 0
Parking/Driveway/Sidewalk 1.42 0.18 902 902
Protected Forest 0.97 0.03 0
Managed Pervious/Landscaping 2.48 1.07 18,366,208 18,360,313 -5,895
Offsite or Existing Roof 1.18 0.11 482,172 482,172 0
Offsite or Existing Roadway 1.64 0.34 0
Offsite or Existing Parking/Driveway/Sidevin 1.42 0.18 572,554 572,554 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 19,420,934.00 19,420,934.00
Project (Regulated)Area 18,366,208.00 18,366,208.00

Nutrient Export Summary
Nutrient Export Summary SNAP v4.2.0
Landcover&SCM Data Review
Errors/Advisories Errors/Advisories
Avg Annual precip(in)= 46.22 SCM Area(ft2) = 0
Total(Regulated+
Unregulated)Area(ftZ)= 19,420,934 SCM Treated Area(ft2)= 0
Project(Regulated)
18,366,208 Catchment Routing: No errors
Area(ft2)=
Net BUA(Project Area Treating Runoff from
5,895 Net BUA indicates new development or expansion. no
BUA only ft2)= Existing BUA or Offsite:
Custom Landcovers are
present:
no Disturbed Area(ft2)= 33,976
Total Nitrogen Export Target lst�.s7 Total Phosphorus Export Target 421630.12 I
Scaled to Project Area(Ib/yr): Scaled to Project Area(Ib/yr):
Total Area Total Area Project Area Total Area Project Area Total Area Project Area
Project Area Total Area Project Area
(Onsite+ Post-Project Post-Project Post-Project Post-Project Post-Project Post-Project
Nutrient Export Summary Offsite) (Onsite Only) before before Post-Project Post-Project SCM-Treated SCM-Treated Untreated Untreated
Pre-Project after Treatment after Treatment
Pre-Project Treatment Treatment Area Only Area Only Areas Areas
Area(All Landcover Types)(acres) 445.8433 421.6301 445.8433 421.6301 445.8433 421.6301 0.0000 0.0000 445.8433 421.6301
Percent Built-Upon Area(BUA)(%) 5% 0% 5% 0% 5% I 0% 0% 0% 5% 0%
Built-Upon Area(BUA)(sqft) 1,054,726 I 0 1,060,621 5,575 1,060,621 5,575 0 0 1,060,621 5,895
Annual Runoff Volume(ft3/yr) 6,656,720 3,183,323 6,675,112 3,201,715 6,675,112 3,201,715 0 0 6,675,112 3,201,715
Annual Runoff%Change A 0% 1% 0% 1%
Total Runoff Change(cuft/yr) AR „ 18,392 18,392 18,392 18,392
Total Nitrogen EMC(mg/L) 1.87 1.25 1.87 2.47 1.87 2.47 0.00 0.00 1.87 2.47
Total Nitrogen Load Leaving Site(Ib/yr) 777.15 492.96 778.46 494.28 778.46 494.28 0.00 0.00 778.46 494.28
1
Total Nitrogen Loading Rate(Ib/ac/yr) 1.74 I 1.17 1.75 1.17 1.75 1.17 0.00 0.00 1.75 1.17
Total Nitrogen%Change Pre-to-Post 0% 0% 0% 0%
Total Nitrogen Change(Ib/yr)Pre-to-Post 1.32 1.32 1.32 1.32
Total Phosphorus EMC(mg/L) 0.59 0.54 0.59 1.06 0.59 1.06 0.00 0.00 0.59 1.06
Total Phosphorus Load Leaving Site(Ib/yr) 244.79 212.69 244.87 212.77 244.87 212.77 0.00 0.00 244.87 212.77
Total Phosphorus Loading Rate(Ib/ac/yr) 0.55 0.50 0.55 0.50 0.55 0.50 0.00 0.00 0.55 0.50
Total Phosphorus%Change Pre-to-Post 0% 0% 0% 0%
Total Phosphorus Change(Ib/yr)Pre-to-Post 0.08 0.08 0.08 0.08
SCM/Catchment Summary
SCM ID and Type Volume TN Reduction TP Reduction TN Out TP Out Falls Lake ONLY: Onsite Reduction Compliance Check
Reduction(%) (%) (%) (Ibs/ac/yr) (Ibs/ac/yr)
Catchment 1 0.00% 0.00% 0.00% 0.00 0.00 I) Nitrogen II Phosphorus
101:NA 0.00% 0.00% 0.00% 0.00 0.00 Onsite%Reduction Requirement
102:NA 0.00% 0.00% 0.00% 0.00 0.00 Export Target Scaled to Area(Ib/yr) 1,517.87 421,630.12
103:NA 0.00% 0.00% 0.00% 0.00 0.00 Export Load Post-Project Before Treatment 494.28 212.77
Catchment 2 0.00% 0.00% 0.00% 0.00 0.00 Total Reduction Need(Ib/yr)
201:NA 0.00% 0.00% 0.00% 0.00 0.00 Onsite Reduction Need(Ib/yr)
202:NA 0.00% 0.00% 0.00% 0.00 0.00 Onsite Export Target(Ib/yr)
203:NA 0.00% 0.00% 0.00% 0.00 0.00 Project Area Post-Project After Treatment i 494.28 212.77
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

Nutrient Offset
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:
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): 18,366,208 Project Latitude: 35.814000
Post-Project Built-Upon Area%: 0.03% I Project Longitude: -78.711000
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 Total TN
TN Untreated TN Treated TN 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)
494.3 1517.9 494.3 0.0 1 100.0% 0.0 0.0
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 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)
212.8 421630.1 212.8 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: