BMP Toolbox - Central Massachusetts Regional Stormwater Coalition

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22 Φεβ 2014 (πριν από 3 χρόνια και 3 μήνες)

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Central Massachusetts Regional Stormwater Coalition

Part 4


Stormwater

BMP Toolbox




Community Innovation Challenge Grant

2013

Central Massachusetts Regional Stormwater Coalition

Objective of the Task


Encourage

small

property

owners

and

developers

to

use

on
-
site

treatment

and

management

of

stormwater
.


Format

existing

materials

to

be

understood

by

the

general

public
.



Create

“Mini
-
Spec”

sheets

for

property

owner

to

hand

to

developer

or

contractor
.



Encourage

good

construction

and

pollution

prevention

practices
.



Not

“reinvent

the

wheel”

Central Massachusetts Regional Stormwater Coalition

Small
-
Site Stormwater Management

Improve Water Quality

a.
Increase groundwater/aquifer
recharge

b.
Improve surface water quality

c.
Reuse stormwater for watering

d.
Protect private property

e.
Reduce adverse impacts to stream
channels

f.
Show the importance of BMP
maintenance

g.
Reduce erosion and sedimentation
during construction

Hiwassee River Watershed Coalition, Inc.

Central Massachusetts Regional Stormwater Coalition

Site Characteristics

1.
Identify

Site

Characteristics

a.
Building

Locations

b.
Impervious

and

Pervious

Areas

c.
Types

of

Impervious

Area

d.
Slopes

and

Contours

e.
Wetlands

or

Drinking

Water

Sources


Central Massachusetts Regional Stormwater Coalition

Pervious and Impervious Area

1.
Determine

Pervious

and

Impervious

A
reas

a.
Design

treatment

and

infiltration

based

on

the

surface

area

of

all

existing

or

proposed

impervious

area
.

2.
Minimize

Impervious

Area


a.
Pervious

areas

are

more

cost

effective

to

maintain

and

construct
.


Central Massachusetts Regional Stormwater Coalition

Soil Permeability

Soil

Permeability
:

ability

of

soil

to

allow

water

to

pass

through

it
.


For

Infiltration

BMP’s

a.
Soils

with

high

permeability

are

desirable
.


b.
Design

requires

calculating

the

correct

area

and

volume

of

water

to

be

stored

and/or

infiltrated

to

prevent

BMP

surcharging
.


c.
Maintenance

is

important

to

maintain

soil

permeability

and

overall

effectiveness
.


Central Massachusetts Regional Stormwater Coalition

Total Suspended Solids (TSS) Removal
Rates

1.
BMPs

minimize

volume

of

TSS

entering

surface

waters

and/or

aquifers

2.
MassDEP

Stormwater

Handbook

is

not

required

for

single

family

homes

or

small

development,

but

guides

effective

BMP

design
.


1.
Requires

80
%

TSS

removal
.

2.
Requires

44
%

TSS

removal




prior

to

infiltration,

if

BMP



is

located

within

a

critical

area
.


Central Massachusetts Regional Stormwater Coalition

Site Limitations and Setbacks

BMP Setback Distances


Setback Item

Setback Distance (Feet)

Septic System

50

Private Drinking Water Wells

100

Public Wells

400

Surface Water Supply (Reservoir)

400

Surface Water Supply Tributary River

200

Any Surface Water

50

Property Line

10

Building Foundation

10
-
100, Depending on BMP


Massachusetts Stormwater Handbook

Natural

site

limitations

include
:

steep

slopes,

wetlands,

surface

waters,

and

seasonal

high

groundwater
.

Central Massachusetts Regional Stormwater Coalition

Minimize BMP Space Requirements

1.
Minimize

stormwater

runoff

by

maximizing

onsite

treatment,

storage,

and

infiltration
.


2.
Retain

stormwater

at

small

sites

with

the

following

design

principles
:

a.
Reduce

building

footprints
;

b.
Cluster

buildings
;

c.
Slope

impervious

surfaces

toward

stormwater

BMP’s
;

d.
Install

vegetated

filter

strips

or

rain

gardens

at

the

end

of

driveways

and

parking

lots
;

e.
Utilize

rain

barrels

or

cisterns
.


Central Massachusetts Regional Stormwater Coalition

Mini
-
Specs

Central Massachusetts Regional Stormwater Coalition

For Each BMP


Description


Benefits


Applicability


Limitations


Level

of

Treatment

Provided


Costs


Common

Applications


Maintenance

Schedule


Resources


Central Massachusetts Regional Stormwater Coalition

BMPs Included in the Toolbox

Pretreatment

BMPs

1.
Street

Sweeping

2.
Deep

Sump

Catch

Basins

Treatment

BMPs

1.
Bioretention

Areas

(Rain

gardens)

2.
Subsurface

infiltration

systems

(
Cultech
,

Stormtech
)

3.
Tree

box

filters

Lance Landscape

Central Massachusetts Regional Stormwater Coalition

BMPs Included in the Toolbox (
cont
)

Infiltration

BMPs

1.
Porous

pavement

2.
Dry

wells

3.
Infiltration

Trenches

Conveyance

BMPs

1.
Drainage

Channels

2.
Water

quality

swales/grassed

channels

Central Massachusetts Regional Stormwater Coalition

BMP “Accessories”

1.
Level

Spreaders

2.
Catch

Basin

Inserts

3.
Rip

rap

4.
Rain

barrels

5.
Cisterns

6.
Erosion

control

measures


Mulching


Hay

bales


Silt

fencing


Biodegradable

mesh

Photo
:

University

of

Southern

Alabama

Photo
:

BMP

Supplies

Central Massachusetts Regional Stormwater Coalition

Erosion Prevention BMPs:

Mulching

Increase

stormwater

infiltration,

reduce

runoff

velocity,

and

provide

more

suitable

habitat

for

seedling

germination
.




Material

Approx. Cost

Remarks

Wood
Chips

$22/Cu. Yd.

Resistant to wind blowing. Decomposes slowly. Can
absorb nutrients from soil.

Bark Mulch

$35/Cu. Yd.

Resistant to wind blowing. Decomposes slowly.

Compost

$20/Cu. Yd.

Most prone to erosion out of natural stabilization
materials. Not recommended for steep slopes.
Excellent moisture conserver. Resistant to wind
blowing.

Hay/Straw

$4/bale

Use straw where mulch is maintained for more than
three months. Subject to wind blowing unless
anchored. Best material for germinating seeds.

Peat Moss

$50/Cu. Yd.

Subject to wind blowing unless kept wet.

Central Massachusetts Regional Stormwater Coalition

Construction Management Practices

Construction

activities

can

contribute

sediment

to

surface

water

bodies,

provide

the

opportunity

for

spills

from

equipment

to

occur

and

for

nuisance

dust

to

be

generated
.

Best

management

practices

can

reduce

the

potential

for

these

issues

to

occur
.



NPDES Construction
General
Permit

vs.

Local Construction
Requirements

Central Massachusetts Regional Stormwater Coalition

Construction Management Practices

Small

Site

SWPPP


Preventing

sediment

transport

is

the





primary

goal

of

a

SWPPP
.



Development
:


*

Owner,

Designer

Contractor


Considerations
:


*

Existing

Site

Conditions





*

Limit

and

Stabilize

Site

Disturbances





*

Keep

Runoff

Velocities

Low





*

Protect

Disturbed

Areas





*

Retain

Sediment

Onsite





*

Include

an

Operation,

Inspection

and





Maintenance

Plan
.







Complete a site walk with all parties




prior to construction
.


GatorGuard

Environmental

Products

Central Massachusetts Regional Stormwater Coalition

Site Staging

1.
Minimize

Disturbance


2.
Avoid

Steep

Slopes

and

Excessive

Grading

3.
Stockpile

Stabilization


4.
Using

Vegetation

for

Stabilization


5.
Dust

Prevention


Central Massachusetts Regional Stormwater Coalition

Equipment and Waste Management

1.
Cleaning

Vehicles

Leaving

the

Site

2.
Fueling

Operations

3.
Construction

Waste

Management


Photo
:

Hong

Kong

EPD

Central Massachusetts Regional Stormwater Coalition

Roles of Professionals in a Residential Project

Central Massachusetts Regional Stormwater Coalition

Integrating LID into Site Design