J_2024 05 09_West Orange Stormwater Management Plan

Outlet Description Orifice Orifice Outlet Pipe (Other) Outlet Type Orifice Orifice Outlet Pipe Orifice Size / Weir Length Invert Elevation 2.5” DIA 12” DIA 18” DIA 164.75 167.25 164.75 9. Vegetation o The vegetation type to be used in this bioretention system is site-tolerant grasses. A Landscaping Plan should be included in the Reference Documents section of this field manual. For a bioretention system designed with an underdrain, the following also applies. 10. Underdrain o The perforated laterals are ____6____ inches in diameter, at a slope of 0.50%. o There are 4 lateral pipes in the basin. Each lateral is approximately 25 feet long. o The perforations are 0.25 inches in diameter and designed per ASTM D2729. o The gravel layer surrounding the underdrain consists of 3 inches of gravel above the underdrain and 3 inches of gravel below the underdrain. Critical Maintenance Features 1. No heavy equipment on the basin surface. 2. Remove vegetation strictly in accordance with the landscaping plan. 3. Grass clippings shall be collected from the basin and properly disposed. 4. Keep the appearance of the basin aesthetic. 5. The system of pop-up drainage emitters and perforated dispersion pipes shall be inspected for blockages when the bioretention basins are inspected. April 2015 Bioretention System Page 29/49

Northwestern Bioretention (2B) Hydrology Design Targets 1. The bioretention system is designed as an online system. 2. The design drain time is 27.50 hours. 3. Due to the water-tight, concrete cell the bioretention is located inside, along with underdrains in the gravel layer, the seasonal high-water table does not exceed beyond 1’ in elevation above the inside bottom of the bioretention cell. 4. Due to the water-tight, concrete cell the bioretention is located inside, along with underdrains in the gravel layer, the field soil permeability is not a factor in the design. Hydraulic Design Targets 7. Design parameters Water Quality Design Storm 1.25 inch in 2 hours 0.013 ac-ft 2-year storm 10-year storm 100-year storm 3.4 inches 5.2 inches 8.7 inches Rainfall Depth in 24 hours In 24 hours In 24 hours (inches) 0.055 ac-ft 0.095 ac-ft 0.175 ac-ft Runoff Volume (ac-ft) 0.48 cfs 0.81 cfs 1.36 cfs 2.44 cfs Peak Flow Rate (cfs) 171.42 172.17 172.38 172.66 Water Surface Elevation (feet) Note: The design engineer shall fill out the table in accordance with the design of the stormwater management measure. If the item is not applicable, enter N/A in the table. 8. The emergency spillway is at EL. ______N/A_____ feet (if applicable). Basin Configuration Targets 1. Pretreatment is not provided. A concrete outlet structure is used. 2. Planting Soil Bed o The depth of the soil planting bed is 3.34 feet. o Mixture of the planting soil consists of 85-95% of sand. (with no more than 25% of the sands as fine or very fine sands; no more than 15% silt and clay with 2% to 5% clay content). The organic matter shall be within 3% to 7%. o The pH of the planting soil should be in the range of 5.5 and 6.5. o Filter fabric is not placed along the sides of the soil planting bed. April 2015 Bioretention System Page 30/49

o The system is designed with a planting soil permeability rate of 1 inches/hour (pre-construction) and __________ inches/hour (post-construction – tested on (MM) / (DD) / (YYYY) ). 3. Outlet Information: Outlet Outlet Type Orifice Size / Weir Length Invert Elevation Description Orifice Orifice 2.5” DIA 170.33 Orifice Orifice 12” DIA 171.83 Outlet Pipe Outlet Pipe 12” DIA 170.33 (Other) 4. Vegetation o The vegetation type to be used in this bioretention system is site-tolerant grasses. A Landscaping Plan should be included in the Reference Documents section of this field manual. For a bioretention system designed with an underdrain, the following also applies. 5. Underdrain (Leave Blank) o The perforated laterals are ____4____ inches in diameter, at a slope of 0.50%. o There are 4 lateral pipes in the basin. Each lateral is approximately 6 feet long. o The perforations are 0.25 inches in diameter and designed per ASTM D2729. o The gravel layer surrounding the underdrain consists of 3 inches of gravel above the underdrain and 3 inches of gravel below the underdrain. Critical Maintenance Features 1. No heavy equipment on the basin surface. 2. Remove vegetation strictly in accordance with the landscaping plan. 3. Grass clippings shall be collected from the basin and properly disposed. 4. Keep the appearance of the basin aesthetic. 5. The system of pop-up drainage emitters and perforated dispersion pipes shall be inspected for blockages when the bioretention basins are inspected. April 2015 Bioretention System Page 31/49

Northern Bioretention (2C) Hydrology Design Targets 1. The bioretention system is designed as an online system. 2. The design drain time is 27.50 hours. 3. Due to the water-tight, concrete cell the bioretention is located inside, along with underdrains in the gravel layer, the seasonal high-water table does not exceed beyond 1’ in elevation above the inside bottom of the bioretention cell. 4. Due to the water-tight, concrete cell the bioretention is located inside, along with underdrains in the gravel layer, the field soil permeability is not a factor in the design. Hydraulic Design Targets 9. Design parameters Water Quality Design Storm 1.25 inch in 2 hours 0.006 ac-ft 2-year storm 10-year storm 100-year storm 3.4 inches 5.2 inches 8.7 inches Rainfall Depth in 24 hours In 24 hours In 24 hours (inches) 0.029 ac-ft 0.050 ac-ft 0.093 ac-ft Runoff Volume (ac-ft) 0.22 cfs 0.37 cfs 0.64 cfs 1.16 cfs Peak Flow Rate (cfs) 171.73 172.26 173.23 173.83 Water Surface Elevation (feet) Note: The design engineer shall fill out the table in accordance with the design of the stormwater management measure. If the item is not applicable, enter N/A in the table. 10. The emergency spillway is at EL. ______N/A_____ feet (if applicable). Basin Configuration Targets 6. Pretreatment is not provided. A concrete outlet structure is used. 7. Planting Soil Bed o The depth of the soil planting bed is 4.5 feet. o Mixture of the planting soil consists of 85-95% of sand. (with no more than 25% of the sands as fine or very fine sands; no more than 15% silt and clay with 2% to 5% clay content). The organic matter shall be within 3% to 7%. o The pH of the planting soil should be in the range of 5.5 and 6.5. o Filter fabric is not placed along the sides of the soil planting bed. o The system is designed with a planting soil permeability rate of 1 inches/hour (pre-construction) and __________ inches/hour (post-construction – tested on (MM) / (DD) / (YYYY) ). 8. Outlet Information: April 2015 Bioretention System Page 32/49

Outlet Description Orifice Orifice Outlet Pipe (Other) Outlet Type Orifice Orifice Outlet Pipe Orifice Size / Weir Length Invert Elevation 2.5” DIA 9” DIA 12” DIA 171.25 173.25 171.25 9. Vegetation o The vegetation type to be used in this bioretention system is site-tolerant grasses. A Landscaping Plan should be included in the Reference Documents section of this field manual. For a bioretention system designed with an underdrain, the following also applies. 10. Underdrain (Leave Blank) o The perforated laterals are ____6____ inches in diameter, at a slope of 0.50%. o There are 4 lateral pipes in the basin. Each lateral is approximately 6 feet long. o The perforations are 0.25 inches in diameter and designed per ASTM D2729. o The gravel layer surrounding the underdrain consists of 3 inches of gravel above the underdrain and 3 inches of gravel below the underdrain. Critical Maintenance Features 1. No heavy equipment on the basin surface. 2. Remove vegetation strictly in accordance with the landscaping plan. 3. Grass clippings shall be collected from the basin and properly disposed. 4. Keep the appearance of the basin aesthetic. 5. The system of pop-up drainage emitters and perforated dispersion pipes shall be inspected for blockages when the bioretention basins are inspected. April 2015 Bioretention System Page 33/49

Visual Aid for Bioretention System Inspection April 2015 Bioretention System Page 34/49

Reference Documents Documents to be placed in this field manual should include the following: - As-built Drawings with Drainage Plans Soil Boring Logs Permeability Test (Pre-construction) Permeability Test (Post-construction) April 2015 Bioretention System Page 35/49

Attach Reference Documents Here April 2015 Bioretention System Page 36/49

Inspection Checklist / Maintenance Actions Bioretention System Checklist (circle one): Quarterly / Annual / Monthly / Special Event Inspection Checklist No. ______________ Inspection Date: _______________ Date of most recent rain event: __________ Rain Condition (circle one): Drizzle / Shower / Downpour / Other _____________ Ground Condition (circle one): Dry / Moist / Ponding / Submerged / Snow accumulation The inspection items and preventative/corrective maintenance actions listed below represent general requirements. The design engineer and/or responsible party shall adjust the items and actions to better meet the conditions of the site, the specific design targets, and the requirements of regulatory authorities. April 2015 Bioretention System Page 37/49

For Inspector Component No. Component Name Inspection Item and Inspection Item No. 1 Scouring or erosion is present at inlet structure and/or riprap apron For Maintenance Crew Result Y__ Preventative / Corrective Maintenance Actions Check the flow diversion device before the inlet pipe and whether the bypass flow channel is clogged N__ Work Order # __________ A1 Pretreatment (Forebay) 2 3 A2 Pretreatment (MTD) A3 Pretreatment (Structural BMP) 1 Clogged pipes or excessive sediment in the forebay Damaged outlet structure (e.g., cracking, subsidence, spalling, erosion, or deterioration) Y__ Remove sediment or debris N__ Y__ Repair or replace the outlet structure N__ Work Order # __________ Y__ (If a MTD is used for pretreatment, see Maintenance Manual Provided by the manufacturer) MTD inspection (if installed) N__ Y__ 1 BMP inspection (See BMP No. ________ Field Manual) N__ Note: April 2015 Bioretention System Page 38/49