Workshop for Contractors,

Developers & Inspectors

Sponsored by:

Carbon, Lehigh and Northampton

County Conservation Districts

and

PA Department of Environmental Protection

January 23, 2008

Erosion and Sediment Pollution Control

and Best Management Practices

Northampton County Conservation District

What we hope to accomplish today

1) Review the impacts of erosion and sedimentation on the environment

2) Clearly define a Best Management Practice (BMP)

3) Illustrate some of the basic BMPs that are specified on an E&S plan

Natural erosion is quite natural (and can be beautiful)

Note: There were no shopping malls or housing developments

in the Colorado River watershed when the Grand Canyon formed

Natural sedimentation

is quite natural

(and can be beautiful)

Accelerated

Erosion

The removal of the surface

of the land through the

combined action of human

activities and the natural

processes, at a rate greater

than would occur because

of the natural process alone

The Power of a Rain Drop

One of the culprits of erosion

Can you name some other natural culprits?

•A raindrop can fall at 25 ft/sec

•A raindrop can displace soil as high as

2 feet vertically

•Once the soil is displaced it can be easily

transported downstream

Some Types of Soil ErosionRaindrop

Stream

Impacts of Soil Erosion

•• Damage to fish and Damage to fish and their food supplytheir food supply

•• Pollution (nutrients, Pollution (nutrients, pesticides, metals etc) pesticides, metals etc) carried along with soilcarried along with soil

•• Loss of storage behind Loss of storage behind reservoirs and damsreservoirs and dams

•• Fouling of water intake Fouling of water intake structuresstructures

Sed

imen

tati

on

Schematic adapted from "Turbidty: A Water Quality Measure", Water Action Volunteers, Monitoring Fact sheet Series,

UW-Extension, Environmental Resources Center.

Sedimentation within Bushkill Creek,

Forks Twp, Northampton County

MONEY

CONSIDERATIONS

• Assessment of penalties on

responsible parties

• Cost to repair

Preventing erosion at its

source is easier than

chasing sediment

downstream

Follow your E&S plan

A Sea of Regulations

• Restaurants are regulated

• Septic system installers are regulated

• Landfills are regulated

• Cosmetologists are regulated

Earth Disturbance is regulated

Best Management Practices (BMPs)Any activities, facilities, measures or procedures used to minimize

accelerated erosion and sedimentation to protect, maintain,

reclaim and restore the quality of waters within the

Commonwealth of PA

Types of Silt Fence Installations

•• Standard silt fence (18” high)Standard silt fence (18” high)

•• Reinforced silt fence (30” high)Reinforced silt fence (30” high)

•• Silt fence reinforced by staked straw bales Silt fence reinforced by staked straw bales

(30” high)(30” high)

•• Super silt fence (33” high)Super silt fence (33” high)

STANDARD CONSTRUCTION DETAIL #19

Standard Filter Fabric Fence (18” High) *Stakes spaced @ 8’ maximum. Use 2"x 2"

wood or equivalent steel stakes.

Filter Fabric Fence must be placed at level

existing grade. Both ends of the barrier

must be extended at least 8 feet up slope at

45 degrees to the main barrier alignment.

Sediment must be removed when

accumulations reach 1/2 the above ground

height of the fence.

Any section of Filter Fabric Fence which has

been undermined or topped must be

immediately replaced with a Rock Filter

Outlet. See Standard Construction Detail #

18.

Top View

Side ViewWater

����Flow

Trench

����6” deep

FUTURE area to be disturbed

Improper

joining

Proper

joining

“My silt fence comes in 100’ rolls but the

plan calls for a 300’ installation (on

existing level grade of course)

What shall I do?

Use the “JOINING

FENCE SECTIONS”

detail on the plan

The PA DEP E&S Control

Program Manual states

“Do not use filter fence in

areas of concentrated

flows (e.g. channels,

swales … across pipe

outfalls, as inlet protection,

etc.)”

Some no no’s

STANDARD CONSTRUCTION DETAIL # 20

Reinforced Filter Fabric Fence (30" High)

Filter fabric fence must be

installed at existing level grade.

Both ends of each fence section

must be extended at least 8 feet

upslope at 45 degrees to the

main fence alignment.

Sediment must be removed

where accumulations reach 1/ 2

the above ground height of the

fence.

Any fence section which has

been undermined or topped

must be immediately replaced

with a rock filter outlet. See

Standard Construction Detail #

18.

Top View

Side View

Water

����Flow

Reinforcing

Stake

10ga

wire

Future earth

disturbance

Future earth

disturbance

30” Reinforced Silt Fence

STANDARD CONSTRUCTION DETAIL #21

Filter Fabric Fence Reinforced by Staked Straw Bales

•Filter fabric fence must be installed at existing level grade. Both ends of each fence section must be extended at least 8 feet upslope at 45 degrees to the main fence alignment.

•Sediment must be removed where accumulations reach 1/ 2 the above ground height of the fence.

•Any fence section which has been undermined or topped must be immediately replaced with a rock filter outlet. See Standard Construction Detail # 18.

Water

����Flow

Existing clean

water detention

basin

STANDARD CONSTRUCTION DETAIL # 22Super Filter Fabric Fence

No. 7 Ga. Tension Wire installed

horizontally at top and bottom of

chain-link fence.

Filter Fabric Fence must be placed at

existing level grade. Both ends of the

barrier must be extended at least 8

feet upslope at 45 degrees to main

barrier alignment.

Sediment must be removed when

accumulations reach 1/ 2 the above

ground height of the fence.

Side View

Water

����Flow

SSF should not be used as

a retaining wall.

Maintenance is just as

important as proper

installation.

Top of super

silt fence

Top of

support posts

Stream

STANDARD CONSTRUCTION DETAIL #18

Rock Filter Outlets

Sediment must be

removed when

accumulations reach 1/3

the height of the outlet.

UP-SLOPE FACE

STANDARD CONSTRUCTION DETAIL #16Rock Construction Entrance

MAINTENANCE: Rock Construction Entrance thickness shall be constantly maintained to the specified dimensions by adding rock. A stockpile shall be maintained on site for this purpose. At the end of each construction day, all sediment deposited on paved roadways shall be removed and returned to the construction site.

Enter and Exit the

site here only

Storm Inlet Protection

• Protect storm sewer inlets when storm sewer does

not discharge to a sediment basin or sediment trap

or when shown on the E&S Plan

• Only use inlet protection devices shown on the

detail sheet of the E&S drawings

• The only types of inlet protection that can be used

are:

• Inlet Filter bags (silt sacks) protection

• Stone & Concrete block protection

• Stone with overflow pipe protection

STANDARD CONSTRUCTION DETAIL #28aFilter Bag Inlet Protection

Channel or Roadside Swale

STANDARD CONSTRUCTION DETAIL #28Filter Bag Inlet Protection

Curbed roadway Maximum Drainage Area = ½ acre.Inlet protection is not required for inlet tributary to sediment basin or trap. Berms required for all installations.

Earthen berm shall be maintained until roadway is stoned. Road

subbase berm shall be maintained until roadway is paved.

Six inch minimum height asphalt berm shall be maintained until roadway surface receives final coat.

DO NOT USE ON MAJOR PAVED ROADWAYS WHERE PONDING MAY CAUSE TRAFFIC

HAZARDS

Water ����

Flow

Side View

Water ����

Flow

Inlet

Inlet

Side View

WATER

����FLOW

DIRECTION

Asphalt berm

Sand bags

Filter bag in inlet

1” Rebar

Removal and disposal of inlet filter bag

STANDARD CONSTRUCTION DETAIL #29Stone & Concrete Block Inlet Protection

Channel or Roadside Swale

Maximum Drainage Area =1 acre.

Inlet protection is not required for inlet tributary to sediment basin or trap. Berms required for all installations.

Earthen berm in roadway shall be maintained until roadway is stoned. Road subbase berm on roadway shall be maintained

until roadway is paved. Earthen berm in channel shall be maintained until permanent stabilization is completed or to remain

permanently.

DO NOT USE ON MAJOR PAVED ROADWAYS WHERE PONDING MAY CAUSE TRAFFIC HAZARDS

STANDARD CONSTRUCTION DETAIL #30Stone & Concrete Block Inlet Protection

Curbed Roadway

or sump condition

curbcurb

STANDARD CONSTRUCTION DETAIL #31Channel or Roadside Swale

Storm Inlet Protection and Berm(s)

STANDARD CONSTRUCTION DETAIL #32Curbed Roadway

Storm Inlet Protection And Berm(s)

* Stone protection is not required for inlet tributary to sediment basin or trap. Berms are required for all installations.

** Earthen berm shall be maintained until roadway is stoned. Road subbase berm shall be maintained until roadway

is paved. Earthen berm in channel shall be maintained until permanent stabilization is completed or to remain

permanently (Detail #31 only).

*** Six inch minimum height asphalt berm shall be maintained until roadway surface receives final coat.

curb curb

One acre maximum drainage area with 15” overflow pipe and 4” head

No

NoNo

No

Inspections of BMPs

are required weekly and

after any runoff event

(rain, snowmelt etc)

We saw a pedestrian slip HERE

STANDARD CONSTRUCTION DETAIL #33Riprap Aprons At Pipe Outlets With Flared End Sections

PLAN VIEW

SECTION Y-Y

SECTION Z-Z

Please note the

table below the

detail on the E&S

plan

TERMINAL WIDTH

Atw

(FT)

INITIAL

WIDTH

Aiw

(FT)

LENGTH

Al

(FT)

THICK

Rt

(IN)

SIZE

(R-__)

APRONRIPRAP

PIPE

DIA

Pd

(IN)OUTLET NO.

This rip rap apron was installed

level (0% slope) per the DEP

Manual

���� Stream flow

Where is the rip rap apron?

Where is the rip rap apron?

STANDARD CONSTRUCTION DETAIL #26Pumped Water Filter Bag

Filter bags shall be made from non-woven geotextile material sewn with high strength, double stitched “J” type seams. They shall be capable of trapping particles larger than 150 microns.

A suitable means of accessing the bag with machinery required for disposal purposes must be provided. Filter bags shall be replaced when they become ½ full. Spare bags shall be kept available for replacement of those that have failed or are filled.

Bags shall be located in well-vegetated (grassy) area, and discharge onto stable, erosion resistant areas. Where this is not possible, ageotextile flow path shall be provided. Bags shall not be placed on slopes greater than 5%.

The pump discharge hose shall be inserted into the bags in the manner specified by the manufacturer and securely clamped.

The pumping rate shall be no greater than 750 gpm or ½ the maximum specified by the manufacturer, whichever is less. Pump intakes

should be floating and screened.

Filter bags shall be inspected daily. If any problem is detected, pumping shall cease immediately and not resume until the problem is

corrected.

Stabilization

• Temporary

– Growing Season

• Seed, mulch, fertilizer, lime

• Matting, stone, etc.

– Non-germinating Season

• Mulch, temporary matting, stone, etc.

• Permanent• Seed, mulch, fertilizer, lime

• Matting, stone, etc.

The PA DEP E&S Control Program Manual states “Upon

completion or temporary cessation of earth disturbance

activity…the project site shall be immediately stabilized”

Straw mulch on a gentle slope

Erosion control

matting in a channel

Asphalt

Some Common Types of StabilizationSome Common Types of Stabilization

Benefits of Mulching

•• Absorbs rainfall impactAbsorbs rainfall impact

•• Increases rate of infiltrationIncreases rate of infiltration

•• Reduces soil moisture lossReduces soil moisture loss

•• Moderates soil temperaturesModerates soil temperatures

•• Provides a suitable germination Provides a suitable germination environmentenvironment

•• Protects seedling from intense sunlightProtects seedling from intense sunlight

•• Used as a temporary stabilization Used as a temporary stabilization during the nonduring the non--growing seasongrowing season

Courtesy www.strawblowers.com

FIGURE 19

Straw Mulch At Various Rates Of Application

Temporary erosion control matting on a steep slope

Staple

Staple

Staple

Staple

Staple

Staple

Staple

Permanent StabilizationPermanent Stabilization

•• Uniform 70% perennial vegetative cover Uniform 70% perennial vegetative cover

of erosion resistant perennial speciesof erosion resistant perennial species

•• Disturbed area covered with other Disturbed area covered with other

acceptable BMP that minimizes acceptable BMP that minimizes

accelerated erosionaccelerated erosion

The staffs of the Carbon, Lehigh, and

Northampton County Conservation

Districts are happy to answer any

questions you may have.