J_2024 05 09_West Orange Stormwater Management Plan

Table of Contents List of Stormwater Management Measures ...................................................................... 2 Location Map ...................................................................................................................... 3 Description of Stormwater Management Measures......................................................... 4 Preventative and Corrective Maintenance Action Plan .................................................... 5 Maintenance Personnel, Equipment, Tools, and Supplies ............................................... 8 Cost Estimate ...................................................................................................................... 9 Training Plan and Records ............................................................................................... 11 Annual Evaluation of the Effectiveness of the Plan ........................................................ 13 Documents ....................................................................................................................... 15 Bioretention System Overview ........................................................................................ 21 Basic Design Information ................................................................................................. 22 Northeast Bioretention (BR-01) ....................................................................................... 22 Western Internal Bioretention (1B) .................................................................................. 24 Central Bioretention (1C) ................................................................................................. 26 Eastern Internal Bioretention (1D) ................................................................................... 28 Northwestern Bioretention (2B) ...................................................................................... 30 Northern Bioretention (2C) .............................................................................................. 32 Visual Aid for Bioretention System Inspection................................................................ 34 Reference Documents...................................................................................................... 35 Inspection Checklist / Maintenance Actions

............................. 34 Reference Documents...................................................................................................... 35 Inspection Checklist / Maintenance Actions ................................................................... 37 Preventative Maintenance Record .................................................................................. 44 Corrective Maintenance Record ...................................................................................... 45 April 2015 Bioretention System Page 20/49

Bioretention System Overview Functionality Bioretention systems are used to remove a wide range of pollutants, such as suspended solids, nutrients, metals, hydrocarbons, and bacteria from stormwater runoff. They can also be used to reduce peak runoff rates and increase stormwater infiltration when designed as a multistage, multi-function facility. A bioretention system can be configured as either a bioretention basin or a longer, narrower bioretention swale. In general, a bioretention basin has a flat bottom while a bioretention swale may have sloping bottom. Runoff storage depths above the soil bed surface are typically shallow. The TSS removal rate for bioretention systems is 80 or 90 percent, depending upon the thickness of the soil planting bed and the type of vegetation grown in the bed. Proper care and attention in the long-term maintenance of the stormwater management measure is critically important to the safety and health of the public. Type of BMP – Dry Basin / Infiltration A bioretention system is a type of dry basin. Dry basins must fully drain within 72 hours of the most recent rainfall. Standing water in excess of 72 hours is a sign of basin failure. It may also contribute to mosquito breeding and other health and safety issues. The design drain time shall be closely monitored to ensure that potential failure is recognized early. A bioretention system with infiltration can also be designed for extended detention, in which case it will attenuate peak flows from storms larger than the Water Quality Design Storm. April 2015 Bioretention System Page 21/49

Basic Design Information Northeast Bioretention (BR-01) Hydrology Design Targets 1. The bioretention system is designed as an online system. 2. The design drain time is 30.00 hours. 3. Due to the water-tight retaining walled and clay lined bottom basin the bioretention is located inside, along with underdrains in the gravel layer, the seasonal high-water is not required to have a foot of separation. 4. Due to the water-tight retaining walled and clay lined bottom basin 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 1. Design parameters Water Quality 2-year 10-year 100-year Design storm storm storm Storm 1.25 inch 3.4 inches 5.2 inches 8.7 inches Rainfall in 2 hours in 24 hours In 24 hours In 24 hours Depth (inches) 0.011 ac-ft 0.043 ac-ft 0.056 ac-ft 0.089 ac-ft Runoff Volume (acft) 0.12 cfs 0.37 cfs 1.52 cfs 2.86 cfs Peak Flow Rate (cfs) 597.68 599.60 600.37 602.39 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. 2. 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 3.0 feet. April 2015 Bioretention System Page 22/49

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%. (775423r0) 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) ). o 3. Outlet Information: Outlet Outlet Type Orifice Size / Weir Length Invert Elevation Description Orifice Orifice 2.5” DIA 162.50 Orifice Orifice 12” DIA 164.50 Outlet Pipe Outlet Pipe 18” DIA 162.50 (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 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 12 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 23/49

Western Internal Bioretention (1B) 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 1. Design parameters Water Quality Design Storm 1.25 inch in 2 hours 0.007 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 0.092 ac-ft Runoff Volume (ac-ft) 0.26 cfs 0.40 cfs 0.67 cfs 1.20 cfs Peak Flow Rate (cfs) 165.20 165.21 166.04 166.76 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. 2. 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 3.13 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. April 2015 Bioretention System Page 24/49

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) ). 3. Outlet Information: Outlet Outlet Type Orifice Size / Weir Length Invert Elevation Description Orifice Orifice 2.5” DIA 164.87 Orifice Orifice 12” DIA 166.40 Outlet Pipe Outlet Pipe 18” DIA 164.87 (Other) (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 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 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 25/49

Central Bioretention (1C) 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 3. Design parameters Water Quality Design Storm 1.25 inch in 2 hours 0.017 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) 0.062 ac-ft 0.102 ac-ft 0.182 ac-ft Runoff Volume (ac-ft) 0.61 cfs 0.88 cfs 1.42 cfs 2.48 cfs Peak Flow Rate (cfs) 165.01 165.71 166.79 167.49 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. 4. 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 4 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 26/49

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 164.00 Orifice Orifice 9” DIA 166.50 Outlet Pipe Outlet Pipe 18” DIA 164.00 (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 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 27/49

Eastern Internal Bioretention (1D) 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 5. Design parameters Water Quality Design Storm 1.25 inch in 2 hours 0.034 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) 0.126 ac-ft 0.209 ac-ft 0.358 ac-ft Runoff Volume (ac-ft) 1.10 cfs 1.53 cfs 2.51 cfs 4.41 cfs Peak Flow Rate (cfs) 166.37 167.54 168.02 168.60 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. 6. 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 28/49