Embed Size (px)
Citation preview
CONTECH Engineered Solutions
Adam Sapp, PE
Why treat stormwater runoff?
• Regulatory Requirement
NJDEP
Post Development Circa 1943
Why treat stormwater runoff?
• Regulatory Requirement
NJDEP
Post Development Circa 1970
Why treat stormwater runoff?
• Regulatory Requirement
NJDEP
Post Development Circa 2007
Why treat stormwater runoff? Pollutants
include:
Excess fertilizers,
herbicides, and
insecticides from
agricultural lands
and residential
areas
Oil, grease, and
toxic chemicals
from urban sprawl
runoff
Sediment from
improperly
managed
construction sites
and eroding
stream banks
When it rains, water flows across the land
and impervious surfaces, carrying with
it pollution
National Trends and Changes
• LID (Low Impact
Development) & Green
Infrastructure (GI)
– Infiltration
– Reuse
– Evapotransportation
– Thermal
considerations
• DC Permit
• EISA, Section 438
(Federal and Military)
– LEED
• Combined Sewer
Overflows
• TMDL (Total Maximum
Daily Loads)
Predevelopment
evapotranspiration: ~40 - 50%
interflow: ~ 20 – 30%
surface runoff: <1%
groundwater: ~10 – 40%
Why LID?
Why LID? – Because Development
has Negative Impacts on the Hydrologic Cycle
Post Development evapotranspiration: ~25%
interflow: 0-30%
surface runoff: ~30%
groundwater: ~15%
Flash flooding
Stream bank erosion
Other problems
What is Low Impact Development?
• Design philosophy for
managing stormwater
• Mimic predevelopment
hydrology and model after
nature
• Reduce, infiltrate, re-use,
evaporate, filter, detain
runoff close to its source
Photo: Seattle SEA Streets Project
5 Principles of LID
1. Conserve natural areas
2. Minimize development impact on hydrology
3. Maintain runoff rate and duration from the site
4. Use integrated stormwater management
practices (IMPs)
5. Implement pollution prevention, proper
maintenance and public education programs
Conventional Low Impact Development
Large Centralized BMP
Xeripave Super Pervious Paver
TM
Stormwater Selection Staircase
• Don’t Disturb
• Don’t use hardscape
• Pervious hardscape
• Bioretention
Pervious Pavement
Benefits: • A cornerstone of LID and Green Infrastructure
• Infiltration reduces runoff and pollutant transport
• Friction courses reduce road spray
• A key element of urban retrofit
Challenges • Installation QA/QC
• Cold climate
• Cost
• Maintenance and Longevity
Pervious Options
Porous Asphalt: 8-10 in/min Permeable Paver Blocks: 1-2 in/min
Pervious Concrete: 8-10 in/min Super Pervious Pavers: 90+ in/min
Super Pervious: An Idea That Doesn’t Hold
Water
•Natural materials
• Size graded aggregates
•High-strength polymer adhesive
• Attractive appearance
•Superior Flow Rates
Super Pervious
Infiltration Rate
• 50 gpm/ft2
• 0.137 cfs/ft2
• 1.65 in/sec
• 5,000 in/hr
Mechanical & Physical Properties
Void Space • 33% to 39%
Size • Nominal Size: 12” x 12” x 2”
• Actual Size: 300mm x 300mm x 50mm
Appearance • Clear finish, decorative value
• No gaps or openings
• Color Options
39% 39%
39% 39%
39%
39%
39% 39% 39%
Hydraulic Properties
So Pervious that…
So Pervious that…
So Pervious That…You Don’t Need That Much!
Designing with Xeripave: Parking Lots
• Use Xeripave for 10% to 20% of parking area
• Expand infiltration zone underneath impervious pavement
• Store the WQV in the sub-grade below larger paved area
• Use traditional pavement in primary travel zones
• Avoid hot spots - dripping oil, grease, or spill zones
• Utilize sheet flow
• Maintain far less surface area
Parking Lot Design
Parking Lot Design
• `
Sizing, Layout and Cross Section
• Start with infiltration rate of
the underlying soils
• Size sub-base depth and
area
– To store the WQv
– Drain down within the time limit
• Grade site for sheet flow
– Minimize slopes
– 10% maximum
• Specify sub-base under
parking area
Pervious Paver
1” Bedding • ASTM No. 8
• ½” to No. 16
4” Base • ASTM No. 57
• 1 ½” to No. 8
Sub-Base • Depth by eng.
• ASTM No. 2
• 3” to ¾”
Sub-grade soil Geosynthetic
Maintenance of Pervious Pavements
• Source control
• Preventive Maintenance – Dry Sweeping
– Entire runoff area
• Remediation – Pressure washing
– Hydro-scrubbing
• Snow – Avoid placing in drive area
– Lifted blade
– Sweeping
• Equipment – Walk behind
– Ride on
– Truck mounted
Many Applications
• Engineers
– Stormwater runoff
reduction tool
• Architects
– New material for
building surrounds
• Landscape
Architects
– Maintain usability and
esthetic value
Wheelchair Accessible
Many Applications: Pedestrian Areas
Many Applications: Tree Surrounds
Many Applications: Driveways
Many Applications: Walkways
Xeripave Super Pervious Paver
TM
Questions?
Benefits of LID
• Habitat protection
• Water quantity benefits
– Reduce imperviousness and runoff volumes
– Groundwater recharge through
• Water quality benefits
– Source control reduces the pollutant amount
– Reduced pollutant loading
• Community value (i.e. increased aesthetics)
LID Challenges
• Conflicts with other municipality codes (i.e. Fire, Public Heath)
• Most Stormwater agencies aren’t set up to maintain IMPs
• Access can be difficult - especially on private sites
• Not effective in controlling peak events. May export landscaping materials in bypass mode.
• Irrigation demand in arid environment poses water conservation challenge
• Vegetation options are limited in arid environments
• Requires precise construction and material sourcing to avoid failure
• Low permeability soils
UrbanGreen Solutions Staircase
Panera Bread - Gaithersburg, MD
Environmental Site Design to the Maximum Extent Practical
- The remaining Stormwater was treated by the StormFilter
Surface Infiltration
• Don’t Disturb
• Don’t use hardscape
• Pervious hardscape
• Bioretention
Eco Roofs
Stadiums and Convention Centers
Philadelphia Water Department: Green Infrastructure to Manage Stormwater
PWD: Philly Water
Department
Surface and Subsurface Infiltration
RWH and LEED
Sustainable Sites • 6.1 Stormwater Quantity
– Pre-development peak and quantity – 1 Point
• 6.2 Stormwater Quality – Reduce annual TSS by 80% – 1 Point
Water Efficiency • 1.0 Water Efficient Landscaping
– Reduce by 50% - 2 Points
– No Potable Use – 4 Points
• 2.0 Innovative Wastewater Technologies – Reduce potable water used for sewage – 2
points
– OR
– 50% onsite treatment – 2 points
• 3.0 Water Use Reduction – 30% reduction from Baseline – 2 points
– 35% reduction from baseline – 3 points
– 40% reduction from baseline – 4 points
LEED 12 • SS 6.1 (Quality) 1
• SS 6.2 (Quantity) 1
• WE 1 (Irrigation) 4
• WE2 (Wastewater) 2
• WE 3 (Indoor water) 4
7
Typical System Components
8
System Components
9
Pre-treatment
Storage
Controls
Pumps
Treatment
Disinfection
Catchment
Makeup H2O
9
System Components: Catchment
Catchment
• Rooftop – cleaner, needs treatment
• Surface – more pollutants
First Flush Management
• Divert first flush
• Wasteful for frequent rainfall
Pretreatment
• Reduce maintenance
• Protect downstream equipment
• Reduce potential for odor
• Screening: 500 um to 2000 um
• Filtration/Separation: 20um to 200um
10
Storage
Controls
Pumps
Treatment
Disinfection
Catchment
Makeup H2O
Code Note: may limit
catchment to rooftop Pretreatment
Code Note: First
flush and
pretreatment may
be required
10
Programmable First Flush and Pretreatment
Passive First Flush Diversion Active First Flush Diversion
• Volume proportional to catchment area
• Bypasses each time it starts to rain
• Can be 5%-40% of annual runoff
• Set rainfall depth and time duration
• Bypasses only when necessary
• <5% of the annual runoff volume
11
To Cistern
Patent pending
CONTECH Products - Pretreatment
• Wall mounted or Underground
• Large treatment capacity
• Full capture
• 100% capture of harvested water
• Non-clogging
• On-line and off-line options
• Economical
• Easy maintenance
12
System Components: Storage
• Above ground, Below ground
• Metal, plastic, concrete, fiberglass
• 1k gal to 1M gal
• Calming inlets, floating outlets
17
Pretreatment
Storage
Controls
Pumps
Treatment
Disinfection
Catchment
Makeup H2O
Code Note:
Calming inlet
and floating
outlet may be
required
UrbanGreen Cistern – Wrapped Cisterns
• Massive Storage – flexible/scalable
• Cost Effective – as low as $0.50/gal
• Combine with Biofiltraiton
• Seal excavation with Pond Liner
• Perforated CMP
• ChamberMaxx
• Life based on liner integrity
18
UrbanGreen Cistern – AGM
Above Ground Metal • Vertical steel tanks
– 72” to 144” diameter
– Heights to 20 ft
• Rated to 8 psi (20ft head)
• Up to 100 Year Life
– Replaceable liner option
• Best Use – Above Ground
– Close to building
– RWH Showcase
– Easy access and maintenance
20
UrbanGreen Cistern – UGM
Underground Ground Metal • Contiguous Tanks
– Up to 48’ Long
– 48” and larger
• Connect Multiple Tanks
• Fully sealed
– Fabrication and seams
– 25-50 year life
– Factory tested upon request
• Rated to 8 psi (tested to 13psi)
• Best Use: General purpose to 100k gal
• 96” x 48’ = 18,000 gallons
H25 Loading, Cover 18” to 20’+
21
Concrete: Terre Box™
UrbanGreen Cistern – SRPE
Steel Reinforced
Polyethylene • Unlimited Length - Long Barrels
– 48” to 120”
• Up to 15 Psi rating
– Bell and Spigot or ElectroFusion
• Longest Life
– Up to 100 yrs for lower pressure ratings
• Best Use – Critical Storage
– Long Life
– Near foundations
– On slopes
– Potable
H25 Loading, Cover 18” to 20’+ 24
UrbanGreen SRPE Cistern – Decatur, GA
UrbanGreen SRPE Cistern – Tucson, AZ
ElectroFusion Coupler
Power Core Heating Coils • Double Seal on each pipe
• Field testable after install
• No water or pressure test needed
Mechanical System Components
Pretreatment
Storage
Controls
Pumps
Treatment
Disinfection
Catchment
Makeup H2O Code Note: disinfection
may be required – even
for irrigation
Typical Components Options • Treatment
– Screens; filters; ultra filtration
– manual or auto back flush
• Make-up Water – Day-tank with air-gap; back-flow preventer
• Disinfection – UV; chlorination
– Instant; recirculation
• Pressurization – Suction pumps; submersible pumps
• Controls – Operation; monitoring ; tie to building mgmt
• Power Supply – 120/240/480v; 1-phase, 3-phase
• Enclosure – Indoor; Outdoor; Underground
Code Note: air gap may
be required, separate
reuse lines required
29
Integrated Mechanical Systems
Building block components
Designed to match project needs
Highly Configurable Pretreatment
Storage
Controls
Pumps
Treatment
Disinfection
Catchment
Makeup H2O
30
Mechanical System – Install Location
Indoor
Skid Mounted
Outdoor
Enclosure
Underground
Vault
31
Design
1) Basic site information
2) Feasibility
3) Design Deliverables
32
(1): Basic Design Information
Project Information Worksheet
Info for Feasibility
• Project location
• Site areas (roof, hardscape, landscape)
• Type of development (commercial, institutional, residential…)
Info for final Design
• Application
• Instant demand and pressure
• Cistern Preference
• Mechanical location – inside/outside
• Power/Voltage
Product Design Worksheet is on our website
33
(3) Design Deliverables
Site Specific Drawings
• Pretreatment
• Cistern
• Mechanical System…
Schematic & Sequence
• Mechanical System
• Pump Locations
• Water supply makeup
• Treatment
• Disinfection
• Order of Operation
Final Runoff Reduction Model
• Runoff reduction
• Water savings
• Financial Savings
34
RWH Runoff Reduction Model
35
Runoff Reduction Model
Modeling
•Continuous daily model
•Local rainfall history
• Seasonal and daily demand
•Seasonal and daily supply
•Outputs:
– Runoff reduction
– Water savings
– Financial savings
Daily/Seasonal Demand
AC Condensation
Toilet
Irrigation
36
VA Net Benefits
Stormwater
• 74% runoff reduction
• 360k gallons/yr
• 100% roof, 50% surface
Municipal Water
• 47% reduction
• 2,300,000 gallons/yr
• 40%+ indoor
Wastewater
• 45% reduction
• 900,000 gallons/yr
• Majority is from re-use water
Stormwater Permitting
LEED 12
• SS 6.1 (Quality) 1
• SS 6.2 (Quantity) 1
• WE 1 (Irrigation) 4
• WE2 (Wastewater) 2
• WE 3 (Indoor water) 4
Financial Savings
• $28,000 per year potential
50
QUESTIONS?
51
Treatment and Detention
Detention and Infiltration Solutions
Choosing the Right Retention/Detention Solution
• Ideal for most vertical depths and applications
• Highly customizable, durable, and versatile CMP
• Most suitable for shallow profile projects
• Stackable and easy to handle ChamberMaxx
• > 3’ profile projects with requiring high voids
• Good option if preference for concrete StormTrap
• Ideal for watertight applications
• Lightweight alternative to concrete DuroMaxx
Corrugated Metal Pipe (CMP)
Cost Effective and Highly
Functional Infiltration Systems
CONTECH CMP
Customizable
CMP
• Flexible configurations
and coatings
• Fully perforated pipe
available
• Diameters from 12” to
144”
• High recycled content for
contributions to LEED®
credits
Plastic: ChamberMaxx®
• Exceed HS-20 live loads
• Offers 49 cf of storage
per chamber
• Multiple pretreatment
options available
• LEED® credits available
• Integral end
Plastic: DuroMaxx®
• Strength and durability
• Available up to 120”
diameter
• Joint tightness
available for all
applications
• LEED® credits
Concrete: Terre Box™
• Wide range of span and rise combinations
• Guaranteed Watertight, no liner required.
• HS25 load rated with no cover.
• Service life > 100yrs
• No Special foundation required.
Concrete: Terre Box™
Geisinger Medical Center
50,000 cu ft installed in 4 days
Concrete: Terre Arch™
• Available in two rises:
26” & 48”
• Fiber reinforced design,
lightweight & strong
• HS25 rating without
cover
• Simple and fast to
install.
• Easy to access &
maintain
Distribution Box Layout
“Just in Time” Delivery
Distribution Box with Terre Arch
Quick Easy Installation
Reduced Manpower
HS-25 Allows Direct Equipment Access
Concrete: Terre Arch™
Full Access to Interior of Terre Arch
Interior View from Arch to Distribution Box
Concrete: Terre Arch™
Advantages
• Underground
Systems
– Full use of the land
– Easy to inspect and
maintain
– Eliminate “pond”
safety issues
– Eliminate vector
control problems
Land Value Calculator
• Opportunity Cost
– Building Revenue, Parking,
Green Space, etc.
• Land Based Costs
– Opportunity Costs, Initial
Costs, Maintenance Costs
• Below-Grade Costs
– Material, Installation and
Maintenance Costs
www.contech-cpi.com/designtoolbox
CONTECH Expertise
1 company + 3 solutions + 7 products = endless configurations
Metal, plastic and concrete detention & infiltration solutions
Detention / Infiltration Design Tools
• DYODS
• HydroCAD Stormwater Modeling Software
• Stage storage curve calculator
www.contech-cpi.com/designtoolbox
Hydrodynamic Separation
VortSentry®
HS
HDS Applications
• Standalone Treatment BMP
– New Development
– Redevelopment
– Retrofit
• LID Pretreatment IMP
– Surface Infiltration
– Subsurface Infiltration
– Rainwater Harvesting
Key Features:
• Adds the only non-blocking screening
technology available to all the benefits of
swirl concentration
• Captures neutrally buoyant debris,
protecting downstream outlet controls
and waterways
• Isolated sump eliminates scour
• Multiple configurations: multiple inlet
pipes; surface inlet; offline; inline
• Internal or external high flow bypass
• Lab and 3rd party field testing, approved
by WADOE, NJDEP and others
Direct Screening CDS Indirect Screening 4700-MICRON
2400-MICRON
Key Features:
• CDS Screen captures neutrally buoyant materials missed by other separator systems
• Screen is hydraulically designed to be self-cleaning and will not become blocked
• Screen pushes debris to center to expedite settling
• Can be designed for various target particle sizes
Installed Internal Components
Diversion
Weir
Separation
Chamber
Oil Baffle (over outlet pipe)
CDS®
N. Hudson Sewerage Authority, Weehawken, NJ
Vortechs®
• Shallow system
• Large swirl chamber
• Proven performance
• Multiple
configurations
Vortechs System
Vortechs®
Vortechs®: Design Flexibility
End Inlet
Side Inlet
Offline
Pretreatment
To Polish
To Outfall
Shallow Horizontal Profile
EXAMPLE: HDS Sizing
Using Equation 405.1, given on page 4-7 of the Philadelphia Stormwater Manual; Section 4.3.1 “Estimate Level of Control Needed” WQv = ( P / 12 ) * ( I ) Where:
WQv = Water Quality Volume (cubic feet) P = 1.0 inch I = directly connected impervious area (square feet)
Example Problem
Given: Total drainage area = 1.38 acres 87% impervious (Impervious drainage = 1.20 acres = 52,298 sq/ft) Calculate the Water Quality Volume
WQv = ( P / 12 ) * ( I ) = (1” / 12) * (52,298 s.f.) = 4,358 cubic feet = 0.100 ac-ft
Step 1 – Calculate the Water Quality Volume
EXAMPLE: HDS Sizing
Step 2 – Determine Peak Flow Rate
• Using HydroCad, model the total drainage area, which consists of 1.20 acres with a curve number of 98, and 0.18 acres with a curve number of 74.
•
EXAMPLE: HDS Sizing
Step 3 – Run HydroCad for Flow Rate Using the SCS TR-20 Runoff Method, with an SCS Type II 24-hour rainfall distribution,
iterate the rainfall depth until the total runoff depth equals the design water quality
volume of 0.100 ac-ft.
rainfall depth of 1.21” results in a runoff volume of 0.101 ac-ft. The resulting design
water quality peak flow rate is 1.68 cfs.
Stormwater Management StormFilter®
• Superior Hydraulics
• Reliable Longevity
• Proven Performance
Stormwater Management StormFilter®
StormFilter Media
PhosphoSorb™ Perlite CSF®
Leaf Media ZPG
Sediments ■ ■ ■ ■
Phosphorous ■ ■
Oil and Grease ■ ■ ■ ■
Soluble Metals ■ ■ ■
Organics ■ ■
Nutrients ■ ■ ■ ■
Use CONTECH as your Environmental Site
Design Resource
• We offer
– In-office support
– Design expertise
– Engineering tools
• In order to:
– Help economize your
solution
– Save you design time
– Add value for your
clients
