Mississauga’s Stormwater Charge

& Suspended Pavement Systems

Webinar

Thursday, November 12, 2015

Agenda

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1:00 – 1:05 p.m.

Introduction Alyssa Cerbu Project Coordinator, Partners in Project Green

1:05 – 1:25 p.m.

City of Mississauga’s Stormwater Charge & Credit Program Jeremy Blair, P.Eng. Storm Drainage Programming Engineer, City of Mississauga

1:25 – 1:45 p.m.

Suspended Pavement Systems Overview Mike James General Manager, DeepRoot Canada Corporation

1:45 – 2:00 p.m.

Question and Answer Period

Pearson Eco-Business Zone

Vision:

An internationally recognized community

known for its competitive, high performance

and eco-friendly business climate.

Coverage: Mississauga, Brampton, Toronto

14,000 hectares

12,500 businesses

350,000 employees

Major sectors: manufacturing, food

processing, logistics, hospitality and aviation

Largest Eco-Business Zone in the World

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Achieve more together than apart

Partners in Project Green Members

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Collective

Infrastructure Projects

Implementation of innovative stormwater management technologies & practices

Innovative Water

Technologies

Water Auditing

Connect cutting-edge technology providers with industrial end-users looking for solutions

Partner with existing regional programs and maximize collaborative opportunities

2015 Water Stewardship Programs Collaboration, Innovation, and Development

For more information, please visit: www.partnersinprojectgreen.com/your-needs/water-stewardship

Delivering programming for all areas of water management

Collective Stormwater Infrastructure Project Calstone Inc.

Utilizing Partners in Project Green’s Network from Conception to Implementation

Speed up the implementation and replication of stormwater

management projects across the Greater Toronto Area

Collective Stormwater Infrastructure

Project Vendor Network

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Permeable Pavement Vendors

Rainwater Harvesting Providers

Green Roof Specialists

Cells & Filters

Providers

Consultants & Engineers

Vendor Network Breakdown:

Please type your questions into the chat bar and we will

get our experts over at City of Mississauga and DeepRoot

Canada to answer!

Housekeeping

Stormwater Charge

and Credit Program Partners in Project Green, Webinar

November 12, 2015

Jeremy Blair, P.Eng.

Storm Drainage Programming Engineer

Transportation & Works Department

Stormwater in Mississauga Why is the City introducing a Stormwater Charge?

Mississauga's stormwater infrastructure

has a current replacement value of

$1.8 billion

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200km of waterways

2100km of storm sewers

Photo Credit: Aaron Volkening

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1000 outlets

60 SWM ponds

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250km of ditches and

swales

48,000 catch basins

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Increased investment is needed to

maintain level of service and state of

good repair

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Flood mitigation

Erosion control 16

Replace aging pipes

SWM pond clean-outs 17

Water quality control

By-law enforcement and spill

response

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Changing climate, changing storms

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User fees are a fair and dedicated way

to fund this essential service

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Stormwater Charges

How are charges assessed and applied?

Stormwater Charge Calculation

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Stormwater Charge

Assessment

(billing units)

Stormwater Rate

($/billing unit)

Stormwater Charge

($)

Stormwater Rate

• Stand-alone, dedicated budget for the City’s

stormwater program

• Reviewed and approved by Council annually

• 2016 Rate is $100 per billing unit

23 billing units

$ /

billing unit

$

Assessment: Residential Properties

Tier Billing

Smalles 0.5

Small 0.7

Medium 1.0

Large 1.2

Largest 1.7

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REPLACE

billing

units

$ /

billing

unit

$

Assessment: Multi-Residential and Non-

Residential Properties

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• Impervious (hard)

surface area of property

individually assessed

• 1.0 Billing Unit per 267m2

(2,874 sq. ft.) of hard

surface area

billing units

$ /

billing unit

$

Stormwater Estimator Look up your property at www.stormwatercharge.ca

26 billing units

$ /

billing unit

$

Stormwater Credits

How are on-site stormwater works considered?

Established

Principles • Credits will reward

stormwater Best

Management Practices

(BMPs) providing direct

City-wide benefits

• Credit amounts will be

proportional to the benefit

received by City’s

stormwater program

Usually on

Private

Property

May occur on

Private Property or

Public System

Usually in

Public System

Original Public

System

Low Impact

Development and

Emerging Practices

Traditional

Infrastructure and

Watercourses

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Program Basics

• Multi-Residential and Non-Residential properties are

eligible

• Maximum credit is 50%

• Credits effective for 5-year, renewable terms

• Applications are accepted for existing or proposed

stormwater BMPs

• Program provides flexibility to property owners in the

BMP types they implement

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30

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Image Credit: Grand Valley State Univresity (www.gvsu.edu/stormwater)

Permeable

Not Permeable

Permeable Pavement

Bioswales

Underground Detention Facility

Green Roofs

Application Package

• All application packages to consist of:

– Completed application form

– Supporting documentation, certified by qualified

P.Eng.

• May submit online, by mail, or in person

• Application form and manual available at

www.stormwatercharge.ca

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Application Types

• New Credit

– First time credit for existing or proposed

works

• Credit Update

– Update credit amount to reflect changes

to stormwater BMPs

• Credit Renewal

– Approved credit about to be or recently

expired

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Focused on how BMPs meet credit criteria

Focused on how BMPs remain in state of good repair

On-Line Information www.stormwatercharge.ca

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Review Process (Existing BMP)

• Step 1: Screen application for completeness

• Step 2: Technical review

– Response to Applicant within 30 days

– Site visit may be required

– Reviewer may have comments for Applicant to address

• Step 3: Decision on credit approval

• Step 4: Credit made effective on account

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Review Process (Proposed BMP)

• Step 1: Screen application for completeness

• Step 2: Technical review

• Step 3: Decision on pre-approval

• Step 4: Applicant submits certification that BMPs are

constructed and operational

• Step 5: Review and decision

• Step 6: Credit made effective on account

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Credit Schedule

Category Evaluation Criteria Weighting

Peak Flow Reduction

Percent reduction of the 100-year post-development flow to pre-development conditions of the site

Up to 40%

Total N

o M

ore th

an 5

0%

Water Quality

Treatment

Consistent with Provincial criteria for enhanced treatment

Up to 10%

Runoff Volume

Reduction

Percent capture of first 15 mm of rainfall during a single rainfall event

Up to 15%

Pollution Prevention

Develop and implement a pollution prevention plan

Up to 5%

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Peak Flow Reduction (up to 40%)

• For full credit: Control 100-year post-

development flow to 100-year pre-

development rate from entire impervious

surface area(s) of site

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Fraction of Target

Met 40%

Credit Amount

Water Quality Treatment (up to 10%)

• For full credit: Direct all impervious areas of

site to an on-site BMP meeting criteria for

water quality

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Fraction of Impervious

Areas Serviced

10% Credit

Amount

Runoff Volume Reduction (up to 15%)

• For full credit: First 15mm of rainfall landing

on all impervious areas of site during a single

rainfall event is captured

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Each mm of rainfall captured

1% Credit

Amount

Pollution Prevention Plan (up to 5%)

• For full credit: Pollution Prevention Plan satisfies

criteria set out in Schedule ‘A’ of the City’s Storm

Sewer By-law 259-05 and is fully implemented

Percent of Pollution Prevention Plan Implemented

Credit Amount

40% 2%

60% 3%

80% 4%

100% 5% 41

Terms and Conditions

• Standard terms and conditions of approval

– May also be site specific

• Expectations for operation, inspection and

maintenance of BMPs

– Logs to be kept by Applicant/Owner for compliance

inspection and/or credit renewal

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Thank You Visit www.stormwatercharge.ca • Charge Estimator

• Reports and Policies

• Request for Review of Stormwater Charge Assessment

• Credit Program

• More Information

Contact us at stormwater@mississauga.ca

Suspended Pavement Systems and

Stormwater Management

Traditional Bio Swale

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• Uses a lot of land

• Collects garbage

• High maintenance cost

Soils: For Stormwater Storage & Tree Growth

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Saturation Point Field Capacity Wilt Point

Macro-pores Micro-pores

• Water movement is highly dependent on soil structure and soil ped retention

• Unscreened top soil/sand mix has a 20% holding capacity for water

(Urban, 2008, Up By Roots)

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So what’s so important about soil?

Glomus intraradices

Microorganisms

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Most tree roots cannot support a large

canopy. Most of the oxygen, water, nutrient

absorption that the successful tree

harvests is via other organisms - fungi,

bacteria, etc.

Tree roots have not had to become super

efficient at harvesting water, oxygen, and

nutrients, because the soil organisms have

been doing this so well for so long.

Reach

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Symbiotic relationship

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Transport

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90% of the water that a tree uptakes is used for transport of nutrients

Evapotranspiration Model for City of Toronto

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Grey vs Green

Suspended Pavement Systems

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1. Pre-Treatment (TSS) 2. Storage 3. Quality

2

3

*sump *chambers / stormwater boxes

clear stone *filters (OGS / Stormceptor)

On going maintenance costs to

maintain filters and clean the

cisterns

Grey Infrastructure

1 1

Green Infrastructure: Trenches

Green Infrastructure replicates bioretention technology under a loaded surface

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Bridging Slab (City of Toronto)

Suspended Slabs or Vaults

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Green Infrastructure provides un-compacted living soil to support tree root

growth and manage stormwater as a source control.

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Soil Cells

Rainwater catchment area

for Silva Cells

Parking Bay Silva

Cell trenches

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Silva Cells and Rainwater Management

The Queensway Sustainable Sidewalk Project Toronto, ON (October 2008)

Design Guideline: Manage the 38mm (1.5”) rain event

Intake Catch Basin

To Soil Cells

(1st Flush)

Overflow

Sump (TSS)

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Perforated drain line is installed at the bottom of the

1st layer of Silva Cells and connected to the storm

water catch basin. Soil is placed in the Silva Cells.

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Intake

Catch Basin

Perforated

distribution pipe

Clean out risers

Stormwater

drains to next CB

Tree Pits

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Decks on Tree Pits

CB

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Oct. 09 Trees planted

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Cumulative Percent Removal by Depth Laboratory/Field Summary

Soil

Depth

Cells

Deep

Cu copper

Pb lead

Zn zinc

P phosphorus

TKN Keldahl

nitrogen

12” 1 90 93 87 0 37

24” 2 93 99 98 73 60

36” 3 93 99 99 81 68

Data on bioretention removal rates of pollutants such as ammonium and total nitrogen is variable, so it’s not included here.

Adapted from Prince George’s County Bioretention Manual

Soil Cells and Soil Filtering Capabilities

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July 2013

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Lidl Store (New Milton, UK)

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East Arques Ave, California

Central Plaza and Stormwater Treatment Area (3500ft2)

4 acres catchment area

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• No new maintenance costs

o Green: No Filters to change or

Cisterns to clean

• Efficient use of space Grey & Green

o No loss of parking

• Benefits of large mature trees - Green

o added storage capacity

o reduction of the heat island

effect

o esthetic values

Advantages

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Challenges of Suspended Pavement Systems

• Higher Capital Costs than Day-lighted Rain Gardens and Bioswales

• More detailed design work needed

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Stormwater Credit Categories

Category Suspended Pavement Systems

Peak Flow Reduction • Cistern or Soil Cell

Water Quality Treatment • Pre- Treatment • Filter systems or soil biology (80%+ TSS removal)

Runoff Volume Reduction • Ground recharge/evapotranspiration/re-use (irrigation)

• 20% storage in the soil volume

Pollution Prevention • Integral part of a pollution prevention plan

PRESENTATION

SLIDES

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Please type your questions into the chat bar and we will

get our experts over at City of Mississauga and DeepRoot

Canada to answer!

Questions?

Upcoming Events

www.partnersinprojectgreen.com/events

Introduction to Building Operator Certification Sustainability Skills Lab Tuesday, November 24th, 2015 www.partnersinprojectgreen.com/events/introduction-to-building-operations-certification-sustainability-skills-lab/

Waste Planning Sustainability Skills Lab Tuesday, January 19th, 2015 www.partnersinprojectgreen.com/events/waste-planning-ssl/

Contact Us

Alyssa Cerbu| Project Coordinator, Water Stewardship

( 416.661.6600 x 5943 | * acerbu@trca.on.ca

www.partnersinprojectgreen.com

Eric Meliton| Project Manager, Water Stewardship

( 647.338.5239| * emeliton@trca.on.ca