Coversheets - Appendices...55 Mary Street West, Suite 112, Lindsay, Ontario K9V 5Z6 Tel: (705)...

SCHEDULE 4.1.1.4

LAKE WILCOX BOARDWALK EROSION AND SEDIMENT CONTROL PLAN BRIEF

RFQ-19-18

55 Mary Street West, Suite 112, Lindsay, Ontario K9V 5Z6 Tel: (705) 878-9399 Fax: (705) 878-9390 Email: [email protected] Website: www.niblett.ca

April 17th, 2018 Project No. 17-036 Paul Marsala Terraplan Landscape Architects 20 Champlain Blvd., Suite 102 Toronto, Ontario, M3H 2Z1 RE: LAKE WILCOX BOARDWALK EROSION AND SEDIMENT CONTROL PLAN BRIEF Dear Mr. Marsala Niblett Environmental Associates (NEA) has been retained by Terraplan Landscape Architects on behalf of the Town of Richmond Hill (Town) to prepare an Erosion and Sediment Control (ESC) Plan brief to support the Lake Wilcox Boardwalk project Ontario Regulation #116/06 Application to the Toronto Region Conservation Authority (TRCA). The ESC Plan was prepared following TRCA’s ESC Design and Submission Requirements (2017), Certified Inspector Sediment and Erosion Control (CISEC) best management practices (BMP), and TRCA project comments, dated October 10th, 2017 and March 19th, 2018. If you have questions or require additional project support, please contact our office. Sincerely,

Amanda Smith, B.Sc.(Hons), CAN-CISEC Fisheries and Aquatic Biologist

Lake Wilcox Boardwalk Erosion and Sediment Control Plan _____________________________________________________________________________________________

Niblett Environmental Associates Inc. 2 PN 17-036

WILCOX LAKE BOARDWALK

EROSION AND SEDIMENT CONTROL PLAN BRIEF

1.0 Project Background

The Lake Wilcox Park project was designed and previously permitted by Toronto Region

Conservation Authority (TRCA) for a period between January 2013 and January 31st, 2015,

Permit No. C-130225. At that time the TRCA also issued a project Letter of Advice on behalf

of the Department of Fisheries and Oceans (DFO). Since the permit has expired, the Town

has reapplied to the TRCA for a permit under Regulation #116/06. Given the dissolution of

the memorandum of understanding between Conservation Ontario and the DFO they have

also submitted a Request for Review to the DFO. To date, the DFO has not completed the

project review.

Terraplan Landscape Architects are the lead project consultant for the TRCA Design and

Approvals application with support from sub-consultants, Niblett Environmental Associates

(NEA) and Shoreplan Engineering Ltd (Shoreplan). NEA and Shoreplan have collaborated on

the Erosion and Sediment Control (ESC) Plan. NEA is the ESC brief lead and Shoreplan is the

ESC engineering drawing lead.

2.0 Project Site and Activity Description

2.1 Project Site Specifications

Permittee: Town of Richmond Hill (Town)

Contact Information: 225 East Beaver Creek Road, Richmond Hill, L4B 3P4, phone: 905-

771-8800, email: [email protected].

Person Responsible for Plan: Amanda Smith, Niblett Environmental Associates (ESC Brief)

and Jane Graham, Shoreplan (ESC Drawing).

Project Name: Lake Wilcox Boardwalk.

Project Location: 55 Olde Bayview Ave, Richmond Hill, ON L4E 3C8. The boardwalk site is

located near the east shoreline of Lake Wilcox (Appendix I).

Receiving Waters: Lake Wilcox.

Project Construction Timeline: July 2018 to December 2018.



2.2 Description of Planned Site

The project is the installation of an elevated boardwalk over Lake Wilcox which is supported

on concrete abutments at the shore ends and vertical steel piles over the lake. The concrete

abutments were constructed under the previous work permits and are utilized in the current

design. A total of 20 piles will be installed to support the boardwalk. Specifically, 18 piles

below the normal water level and two piles above the normal water level within the

established riparian vegetation habitat (Appendix I).

A temporary berm will be installed to facilitate footing and pile installation. To prepare for

the temporary berm installation, two areas will require vegetation cutting. The vegetation

will be cut level to the ground. The soil and all vegetation roots will not be disturbed to retain

the soil cover, stability, and protect against erosion post-construction. Vegetation on either

side of the north and south berm abutments may be disturbed by construction machinery,

however, no tree cutting will occur.

A temporary access berm is required to provide machinery access to the boardwalk location

in Lake Wilcox. Barge access is not feasible due to the shallow water depths of the site. The

average fall water depth was 0.5 m in 2017 within the boardwalk footprint (Niblett

Environmental Associates, 2018).

The temporary access berm will be built by laying down geotextile, geogrid, and 50 mm clear

stone (Appendix I). The berm will be in place for approximately 6 months and removed in

the month of December.

The existing in-water fish habitat structures (boulders and woody debris) will be removed

from the access berm footprint prior to installation, stockpiled, and replaced upon

completion. Site rehabilitation details have been provided in the Rehabilitation Plan,

provided in project Environmental Impact Study (EIS) (Niblett Environmental Associates,

2018). The site will be completely stabilized and restored by the spring 2019.

2.3 Nature of Construction Activity Function of the Project: The project consists of installing an elevated boardwalk for the

waterfront parkland. The construction activities on site will consist of cutting existing

vegetation to ground level, in-water and shoreline pile driving and excavation to install the

boardwalk piers.



Sequence of Major Activities: Construction tasks to be completed will include the following

sequential activities.

o Installation of sediment fence and turbidity curtain.

o Cutting of vegetation to the ground in identified areas.

o Installation of temporary berm.

o Installation of piers.

o Installation of boardwalk.

o Removal of temporary berm.

o Removal of turbidity curtain prior to significant ice formation.

o Second installation of sediment fence

o Vegetation restoration

o Removal of sediment mitigation measures once the site fully stabilized.

2.4 Environmental Conditions of Existing Site

The site is an active waterfront parkland with a restored shoreline and waterfront

promenade. The proposed elevated boardwalk will be located over Lake Wilcox and its

shoreline riparian habitat. The shoreline and littoral habitat of the lake provide permanent

aquatic habitat for fish, aquatic invertebrates and wildlife. The shoreline was restored during

the original project works through upland plantings, in-water structure installation for fish,

and amphibian habitat including; embedded large woody debris and boulder clusters.

The shoreline is comprised of a mosaic of crack willow (Salix fragilis), deciduous swamp

(SWD4-1) and thicket swamp (SWT2) that is characterized by dense patches of sandbar

willow (Salix exigua) and European black alder (Alnus glutinosa). Between the shoreline and

the Lake Wilcox Park trail lies a strip of meadow habitat that was recently disturbed and is

now regenerating predominantly with species that appear to have been planted and/or

seeded following the construction of previous developments. The east side of the trail

includes maintained lawn areas and a system of narrow ditches vegetated with common

wetland species.

2.5 Conditions of Existing Receiving Water

Lake Wilcox is a cool water kettle lake with a surface area of 48.9 km and maximum depth of

4.8 m. Wilcox Lake supports a diverse fish community with species that prefer both

warmwater and coolwater thermal habitats. Desirable recreational fish species include,

Northern Pike, Yellow Perch, Common Carp, Large and Smallmouth Bass. No aquatic species

at risk habitat are documented in Lake Wilcox (OMNR, 2012).



2.6 Adjacent Areas and Features

The adjacent land includes Lake Wilcox, a waterfront recreational park, and the Richmond

Water Park and Canoe Club. The remaining lands surrounding Lake Wilcox are dominated

by shoreline residential housing developments.

3.0 Soils and Erosion Potential

3.1 Soil Description

The project geotechnical study by Sola Engineering Inc. reported that surface soils varied.

Silty sand with a trace of organic matter, clayey silt and sand with a trace of gravel were

encountered at all three borehole locations (Sola Engineering Inc., 2017). The sandy clay to

clay range of soils is less erodible and has a low soil erodibility rating on the Hierarchy of Soil

Erodibility.

3.2 Evaluation for Erosion Potential

An evaluation for erosion potential was completed following the Erosion and Sediment

Control Guideline for Urban Construction, Appendix A (GGHA, et al. , 2006).

The soils erodibility rating for the boardwalk site is low given the soil type ranges from sandy

clay to sand. The site slope is moderate (2-10%) between the walkway and shoreline and

the slope length is < 30m. Therefore, the erosion potential for a graded slope is low. The

potential for slope erosion is further minimized by the absence of grading and site soil

disturbance. Where vegetation removal is required, the roots and stalks will only be cut to

the soil surface avoiding soil disturbance.

3.3 Critical Areas for Erosion

The site does not have potential for serious erosion or sedimentation issues. The shoreline

is vegetated and the soils are stable. Four upland areas have the potential to be temporarily

disturbed during the construction phase. All areas have a low potential for erosion or

sedimentation from the proposed works.

Cutting of the shoreline vegetation to the ground will occur in two locations, the temporary

berm access ramp (~4 m x 9 m) and southern riparian connection (~8 m x 4 m).



Temporary vegetation disturbance by workers and small machinery may occur in two

locations; the north and south boardwalk abutments. The disturbance will include

disturbance of understory vegetation to install shoreline piles, P1 and P20. No tree removal

will be required.

The in-water pile installation (P2-P190) has a low to moderate potential for sedimentation

and settling of suspended sand particles off-site.

4.0 Design Details of Erosion and Sediment Control Measures

Erosion control is the most effective method to protect Lake Wilcox during and after

construction. The erosion potential of the site soils are low and the project has been designed

to minimize the extent of shoreline disturbance, further reducing the potential for erosion.

The following sediment and erosion control measures will be used to minimize erosion and

prevent the movement of sediment into Lake Wilcox and off-site.

Refer to the attached erosion and sediment control drawing by Shoreplan for information

related to the placement of the mitigation measures and Ontario Provincial Standard

Drawings (Appendix I).

4.1 Erosion Control

Vegetation Filter Strip- the existing riparian vegetation will remain undisturbed, with the

exception of the four vegetation disturbance areas, as discussed in Section 2.2. The berm has

been designed to maintain the existing shoreline vegetation and current function as much as

possible. Perimeter snow fencing will be installed between the walkway and riparian

vegetation to prevent construction vehicles from entering the area and protect the

vegetation filter strip.

Mechanical Seeding – All disturbed vegetation areas will be seeded with a native seed mix to

provide long term soil stabilization. The seeds will be broadcasted in the spring (April-May)

and left for 30 days or longer to germinate. Seeded areas will be visually marked to prevent

pedestrians from disturbing the seeded areas. A minimum of 150 mm of topsoil will be

provided if adequate topsoil is not present. No site grading or grubbing is proposed;

therefore, it is expected adequate soils will be present at the time of seeding. The contractor

will be prepared to apply topsoil if needed to ensure the successful established of vegetation.

Mechanical seeding will be completed by a professional landscaping company.



Livestake Plantings- In addition to seeding, live-stakes and plantings will be installed in the

disturbed areas to provide long term soil stabilization. Only native species will be planted.

The EIS provides full restoration details on the plant species, numbers, and locations (Niblett

Environmental Associates, 2018). Livestaking will be completed by a professional landscape

company.

4.2 Sediment Control Practices Turbidity Curtain (OPSD 219.260) - The entire in-water work area will be isolated with a

turbidity curtain. The curtain will create a barrier to contain isolate and contain disturbed

lake bed sediment and prevent aquatic life from entering the construction site. The curtain

will be installed prior to any in-water or shoreline works and remain in place over the entire

construction period. It will be installed by boat and wading.

Minor dewatering will occur for the foundations sheet pile box enclosures. No dewatering is

required for the berm construction. The following measures will be included in the

dewatering plan.

• Discharge of all pumped waters will occur outside of the foundation sheet pile box

enclosures (active work space) and within the turbidity curtain isolated work area.

• No water will be discharged outside the turbidity curtain without the use of a filter

bag. All pumped water discharged outside of the turbidity curtain will be treated to

minimize sediment transportation into Lake Wilcox, the receiving watercourse.

Water treatment methods may include a filter bags located in an undisturbed densely

vegetated area that will not be disturbed by construction. The location should be

naturally vegetated to slow discharge flows and prevent additional erosion and

sedimentation.

• A backup pump and extra hoses will be on-site at all times during de-watering works.

Sediment Fence (ODSP 219.131 min. 270R non-woven geotextile)- Sediment fence will be used

as a perimeter control to prevent sediment from being transported into Lake Wilcox within

disturbed shoreline areas. Sediment fence will be installed along the shoreline to protect

against potential sedimentation from activities associated with the P1 to P20 installation

works. The fence ends will have a “J” hook orientation to capture all potential sediment

moving down the riparian edge toward the shoreline (Appendix II). This additional

protection will also reduce the extent of shoreline restoration post-construction.



Heavy duty sediment fence is recommended and reinforced with wire fencing and adequate

support. Sediment fence will be installed prior to construction.

When the construction is completed, the two areas where the vegetation was cut to the

ground will be stabilized and can overwinter without additional erosion protection provided

the soils were not disturbed and all roots and stumps remained undisturbed. Heavy duty

sediment fence will be installed at the toe of slope to provide sediment control and protect

Lake Wilcox from any potential sedimentation during the winter thaw, precipitation events

or the spring freshet.

Erosion Control Matting- As a contingence measure, erosion control matting will be installed

in any areas where the soil has been disturbed. Erosion control mats are prefabricated

layers of material, generally biodegradable, which are laid on a soil surface to prevent

erosion and promote seed growth. Mats are typically composed of 100% coconut husk fibers

or synthetic polypropylene fibers to provide a stronger/heavier material layer or “mat”.

Erosion control mats should be applied to all exposed slopes that are subject to rainfall and

runoff. A firm, continuous contact between the blanket and soil is critical. Careful rolling after

installation and stapling may be required to obtain firm contact. Care must be taken during

installation to remove all foreign debris (i.e. rocks, branches, plastics) to prevent the mats

from tenting due to lack of firm contact with the soil surface. Tenting creates a drip zone

which causes erosion under the blanket (i.e. distance between blanket and soil surface).

An OPSD sheet is not available, therefore, the manufactures instructions must be followed

for installation, stapling and spacing. The mats should be oriented vertically down the slope,

in the direction of runoff (GGHA, et al. , 2006).

4.3 Permanent Stabilization

The project does not include grubbing, grading or stripping of any land. The vegetation will

be cut to the ground leaving all stumps, roots and the soil undisturbed in two locations to

allow the berm installation. As discussed in Section 4.1, mechanical seeding and plantings

will be completed in the spring to rehabilitate the site and provide permanent stabilization.

The site will be planted in the following spring (April-May).

4.4 ESC Best Management Practices

The following mitigation measures apply to the entire site.

• All ESC measures shall be installed, maintained and removed in accordance with the

attached Best Management Practices (BMP), Ontario Provincial Standard



Specification (OPSS) standards for temporary sediment and erosion control.

Measures and product specifications. A minimum 270R geotextile or equivalent will

be used.

• In the event that ESC measures are not functioning, the construction supervisor shall

immediately remediate by making the necessary adjustments to the construction

methods and/or the ESC plan to address the sediment/erosion problem to the

satisfaction of the site inspector and the environmental consultant.

• Construction will be undertaken during normal weather conditions, to the extent

possible, and will avoid large precipitation events to minimize the risk of

sedimentation off-site.

4.5 Non-Storm Water Components of Discharge No water will be discharged outside the turbidity curtain without the use of a filter bag. All

pumped water outside of the turbidity curtain will be treated to minimize sediment

transportation into Lake Wilcox. Turbidity curtains will be removed prior to significant ice

formation conditions.

5.0 Construction and Waste Materials

5.1 Stockpile Details

Stockpile material will consist of material removed from the construction area (boulders and

logs) that will be replaced upon completion. No other materials are expected to be stored on

site due to the lack of staging space.

All materials will be stored and stabilized away from the water above the high-water mark

and as far away from the waterbody as possible. A minimum 30 m distance is typically

recommended but may not be feasible for this project. Stockpiles will be enclosed by

sediment fencing or installed downgradient for the purpose of preventing movement of

sediment away from the stockpile and into a water feature.

5.2 Refueling and Spills

It will be the responsibility of the contractor to take appropriate actions to ensure pollution

of storm water does not occur. Fueling areas will be at least 30 m (100ft) from drainage



channels and/or storm sewer systems. The contractor will be responsible for protecting the

soil from contamination due to hydrocarbon and other hazardous spills associated with his

contractual obligations.

Refueling of machinery should be carried out on hardtop surfaces at a minimum of 30 m

distance from the water at a site designated by the Town representative. Areas where

equipment refueling and maintenance will occur should be equipped with adequate

containers for the disposal of wastes produced from upkeep and repair. Keep an emergency

spill kit on site in case of fluid leeks or spills from machinery.

An emergency spill kit shall be kept on site, and employed immediately should a spill occur.

In the case of a spill, deleterious substances should be immediately contained and cleaned

up in accordance with provincial regulatory requirements. Spills should be reported to

Ontario Spills Action Centre at telephone 1-800-268-6060. Contractor is responsible for any

cleanup or repair resulting from any spills. All provincial and federal regulations shall be

adhered to.

5.3 Machinery The following mitigation measures will be followed to minimize sediment and contaminate transportation.

• Check heavy equipment, machinery and tools prior to entering the work site to ensure they are clean and free of leaks.

• All heavy equipment, machinery, and tools required for the work shall be regularly

inspected and maintained to avoid leakage of fuels and liquids, and shall be stored in

a manner that prevents any deleterious substance from entering the soil, or nearby

watercourses.

• Vehicle and equipment refueling and/or maintenance shall be conducted a minimum

of 30 m from all watercourses. Any part of a vehicle and/or equipment entering the

water will be free of fluid leaks and externally cleaned/degreased to prevent

deleterious substances from entering the water.

• The Project Manager/Contractor shall not allow any deleterious substances as

defined in the Fisheries Act (such as silt), caused by the work, to enter or re-enter the

watercourse.



• Maintain an adequate supply of clean-up materials on-site and keep an extra turbidity

curtain on-site during construction. Construction crews will be fully trained in their

use to ensure timely and effective responses to spill incidents.

6.0 Species At Risk There are no known species at risk for this project (Niblett Environmental Associates, 2018).

7.0 Inspection and Maintenance

7.1 Inspection Timing

Inspection of erosion and sediment control measures will occur after any significant wind or

precipitation event which may cause runoff. As a minimum, inspections of all erosion and

sediment control measures will occur at least every 14 days by the site inspector while

construction activities occur. All protection should be installed and functioning as detailed

in the manufacturer’s instructions.

After construction is completed, inspections will occur once a month until final stabilization

of the site has occurred. Final stabilization is defined as vegetation cover of at least 70% of

the historic conditions and 100% build out of the boardwalk and restoration plan.

7.2 Maintenance of Erosion and Sediment Control Measures

At a minimum, maintenance of the erosion and sediment control measures will include the

following:

• Removal of accumulated sediment collected by the measure once a 50% reduction of

the storage capacity for the structure is evident.

• Repairing damage to sediment control structures.

• Adding or eliminating erosion and/or sediment control measures as deemed

necessary.

• Immediate repair and/or replacement of ESC measures when failure occurs or the

mitigation measures are ineffective.

• All sediment and erosion control products will be selected and installed for the site

based on the manufacturer’s product specifications. Product installation and

maintenance will follow the manufactures guidelines.



7.3 Record Keeping Procedure Records of each inspection will be retained by the contractor or their representative. An

example form has been provided in Appendix III.

8.0 Emergency Contact

1. Town of Richmond Hill (Land Owner)

225 East Beaver Creek Road,

Richmond Hill, L4B 3P4,

Phone: 905-771-8800, Email: [email protected]

2. Site Supervisor (to be updated when construction contract awarded).

9.0 Stamped and Signed

The ESC Plan was developed in consultation with Shoreplan.

10.0 References GGHA, et al. . (2006). Erosion and Sediment Control Guidelines for Urban Construction.

Toronto: Greater Golden Horseshoe Area Conservation Authorities.

Niblett Environmental Associates. (2017). Wilcox Lake Boardwalk Environmental Impact

Assessment . Lindsay: NEA.

OMNR. (2012). Aquatic Resource Area Survey. Peterborough, Ontario: Land Information,

Ontario Ministry of Natural Resources.

Sola Engineering Inc. (2017). Geotechinical Investigation, Proposed Lake Wilcox Elevated

Pedestrian Walkway Assignment; Lake Wilcox Park, Richmond Hill, Ontario. Toronto,

Ontario: Sola Engineering Inc.


Niblett Environmental Associates Inc. PN 17-036

APPENDIX I: WILCOX LAKE EROSION AND SEDIMENT CONTROL PLAN, SHOREPLAN - EV1

294.50

EROSION CONTROLMATTING (TYP.)

EXISTING CONCRETEABUTMENT, SEEGENERAL NOTE 8

TEMPORARY ACCESSBERM (TYP.)


FAST FENCE ORAPPROVED EQUAL


POST CONSTRUCTIONSEDIMENT FENCE (TYP.)

PRE & POST CONSTRUCTIONSEDIMENT FENCE (TYP.)

TURBIDITY CURTAIN 600mm Ø CSP TEMPORARY CULVERTPROVIDE COVER AS PER OSPD 802.010,SEE DETAIL SHEET P3 AND NOTE 7


PRE & POST CONSTRUCTIONSEDIMENT FENCE (TYP.)

Not to Scale LOCATION PLAN

SPECIFICATIONS:

1. Work includes preparation of the access to the site, demolition and/or removal and replacement of itemsindicated on the contract drawing or required to complete the specified work, tree and brush removalrequired to complete the work, removal of existing armour stone and boulder structures and other sitepreparation tasks required to complete the specified works, disposal of the derived or excess material in alegal manner, and the restoration of the site and access routes to existing or better conditions. Erect anysilt curtains or fences as required by conditions of approvals and comply with any and all conditionsoutlined on permits.

2. Site preparation and restoration measures should follow the Restoration Plan Brief,appendix IV of the Enviromental Impact Study (NEA, 2018).

3. Details on EV1 and EV2 prepared as per environmental consultant: Niblett Environmental Associates Inc.55 Mary Street W, Suite #112 Lindsay Ontario K9V 5Z6. Telephone: 705-878-9399.

EROSION AND SEDIMENT CONTROL NOTES

1. Erosion and Sediment Control (ESC) measures will be implemented prior to, and maintained during theconstruction phases, to prevent entry of sediment into the water. All damaged erosion and sediment controlmeasures should be repaired and/or replaced within 48 hours of the inspection.

2. Sediment tracked onto offsite street will be removed weekly or as needed.

3. Stockpile will be located by the Contractor and protected from erosion as directed by the engineer.

4. All catch basins within the work area to be protected with sediment sock.

5. All catch basins, silt barriers and mud mats to be cleared of sediment as required after storm event or asidentified during site visits.

6. Erosion and Sediment Control measures should follow recommendations in Niblett EnvironmentalAssociates Inc. letter dated September 12, 2017. Any deviations from this letter should be approved by theengineer.

7. The erosion and sediment control strategies outlined on the plans are not static and may need to beupgraded/amended as site conditions change to minimize sediment laden runoff from leaving the workareas. If the prescribed measures on the plans are not effective in preventing the release of a deleterioussubstance, including sediment, then alternative measures must be implemented immediately to minimizepotential ecological impacts. TRCA Enforcement Officer should be immediately contacted. Additional ESCmeasures to be kept on site and used as necessary.

8. Any dewatering to be discharged within turbidity curtain containment zone.

9. Any disturbed soil to be enclosed with sediment fence.

SITE

NOTE:CONSTRUCTION ACCESS ALONGSUNSET BEACH ROAD AND PARKWALKWAY

S

U

N

S

E

T

B

E

A

C

H

R

O

A

D

Scale 1:200 EROSION & SEDIMENT CONTROL MEASURES

1. All dimensions in millimeters unless indicatedotherwise.

2. All elevations in meters, GSC.

3. All equipment shall be refueled at least 30meters from the lake.

4. Any operation that creates dust, such as stonecutting, shall be carried out away from thewater to prevent dust entering Lake Wilcox.

5. No in water work shall be carried out betweenMarch 15th and July 15th.

6. Construction access berm to be removed uponcompletion of work and disturbed areas to berestored to existing or better condition.

7. Adjust location of culvert as required to provideadequate cover over culvert for constructionaccess.

8. Confirm location of abutments before locatingbridge pile supports. Report any variances tothe engineer immediately.

9. Bridge bearing piles to support load of 310 KN.Engineer to be present during pile driving toconfirm bearing capacity.

10. Remove all soft material from pile box prior toplacing concrete. Report any variation toengineer prior to exceeding excavated depthshown on details.

11. For site preparation, restoration and erosionsediment control measures see sheet EV1 andEV2 and reference drawings as listed on coverpage.

12. The Contractor shall read detailedspecifications contained in tender documentsand contract. In case of conflict betweenspecifications in tender documents, thedetailed specifications in the tender shallgovern.

plan

GENERAL NOTESKEY MAP - N.T.S.

TENDER No.CHECKED

DRAWN DESIGNED

APPROVED

DRAWING TITLE

PROJECT NAME

DRAWING No.

NORTH STAMP

No. DATE REVISIONS BY

SCALE

PARKS DESIGN & CONSTRUCTION SECTIONENVIRONMENT & INFRASTRUCTURE SERVICES

- - -

EXISTING CONDITIONS

XX XX 1: XXX

XX XX RFQ-XX-XX

EX

01 2017-09-22 ISSUED FOR REVIEW DM

LAKE WILCOX BOARDWALK

FILE NO. 16-2512

- - -

LAKE WILCOX PARK BOARDWALK PIERS

S.M.

J.G. RFQ-XX-XX

EV1

EROSION & SEDIMENT CONTROL MEASURES

0101 2017-08-02 ISSUED FOR APPROVAL ONLY J.G.

02 2017-08-29 ISSUED FOR REVIEW J.G.


04 2017-10-02 ISSUED FOR APPROVAL M.S.

B.L.

M.S.


LEGEND

Turbitity Curtain

Existing LakeBottom Elevation

XXX.XX

PRE-CONSTRUCTION

TREE PROTECTION FENCE

STAKING (WILLOW, DOGWOOD) &SEEDING INTERPLANTED

LIMBING/TRIMMING AND ROOT PROTECTIONTO BE OVERSEEN BY ARBORIST

EROSION CONTROL MATTING

CALIPER TREE PLANTING

CONSTRUCTION FENCING.FAST FENCE OR APPROVED EQUAL

LEGEND

POST-CONSTRUCTION

TURBITITY CURTAIN SEE DETAILS SHEET P3(OPSD 219.261/219.260)

AQUATIC HABITATRESTORATION AREAS

POST-CONSTRUCTION SEDIMENTFENCE (OPSD 219.110)

PRE-CONSTRUCTION SEDIMENTFENCE (OPSD 219.110)

PRE CONSTRUCTIONSEDIMENT FENCE (TYP.)

PRE CONSTRUCTIONSEDIMENT FENCE (TYP.)

06 2018-04-12 ISSUED FOR TENDER M.S.

EXISTING CONCRETE WALKWAY NOTTO BE DISTURBED, CONTRACTORRESPONSIBLE TO REPAIR ANYDAMAGE TO WALKWAY DUE TOCONSTRUCTION



EXISTING ARMOUR STONE ANDBOULDER STRUCTURE. REMOVE ASREQUIRED FOR CONSTRUCTIONACCESS. REPLACE UPONCOMPLETION OF WORK.


294.50

FISH HABITAT FEATURES TO BE REMOVEDAS REQUIRED FOR CONSTRUCTION ACCESS. REPLACE UPON COMPLETION OF WORK.

TEMPORARY ACCESSBERM (TYP.)

TURBIDITY CURTAIN TEMPORARY CULVERT

EXISTING CONCRETE WALKWAY NOTTO BE DISTURBED, CONTRACTORRESPONSIBLE TO REPAIR ANYDAMAGE TO WALKWAY DUE TOCONSTRUCTION



EXISTING ARMOUR STONE ANDBOULDER STRUCTURE. REMOVE ASREQUIRED FOR CONSTRUCTIONACCESS. REPLACE UPONCOMPLETION OF WORK.


294.50













plan

GENERAL NOTESKEY MAP - N.T.S.

TENDER No.CHECKED

DRAWN DESIGNED

APPROVED

DRAWING TITLE

PROJECT NAME

DRAWING No.

NORTH STAMP


SCALE


- - -

EXISTING CONDITIONS

XX XX 1: XXX

XX XX RFQ-XX-XX

EX



FILE NO. 16-2512

- - -


S.M.

J.G. RFQ-XX-XX

EV2

SITE PREPARATION & RESTORATION





B.L.

M.S.

Scale 1:300 PRE-CONSTRUCTION VEGETATION PROTECTION MEASURES


LEGEND

Turbitity Curtain


XXX.XX

Scale 1:300 POST-CONSTRUCTION VEGETATION RESTORATION MEASURES

PRE-CONSTRUCTION

TREE PROTECTION FENCE

STAKING (WILLOW, DOGWOOD) &SEEDING INTERPLANTED

LIMBING/TRIMMING AND ROOT PROTECTIONTO BE OVERSEEN BY ARBORIST

EROSION CONTROL MATTING

CALIPER TREE PLANTING

CONSTRUCTION FENCING.FAST FENCE OR APPROVED EQUAL

LEGEND

POST-CONSTRUCTION

TURBITITY CURTAIN SEE DETAILS SHEET P3(OPSD 219.261/219.260)

AQUATIC HABITATRESTORATION AREAS

POST-CONSTRUCTION SEDIMENTFENCE (OPSD 219.110)

PRE-CONSTRUCTION SEDIMENTFENCE (OPSD 219.110)


NOTE:

1. Site preparation and restoration measures should follow the Restoration Plan Brief, appendix IV ofthe Enviromental Impact Study (NEA, 2018).

CONSTRUCTION ACCESS

0m 5025 25 75

FAST FENCE WITH GATE,OR APPROVED EQUAL

STAGING AREANO CONSTRUCTIONMATERIAL TO BESTORED OUTSIDETHIS AREA.

FAST FENCE OR APPROVED EQUAL AS REQUIREDTO RESTRICT ACCESS TO WORK AREA

EXISTING LANDSCAPE FEATURES ANDVEGETATION NOT TO BE DISTURBEDEXISTING LANDSCAPE FEATURES AND

VEGETATION NOT TO BE DISTURBED

TEMPORARY ACCESS BERM (TYP.)50 mm Ø CLEAR STONE TO BEREMOVED UPON COMPLETION

APPROXIMATE LOCATIONOF SOLA BOREHOLE BH-3(JAN 2017)



SUBMERGEDSTEEL SHEET PILEENCLOSURE TYPE 1

SUBMERGEDSTEEL SHEET PILEENCLOSURE TYPE 2

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5m

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25m±

3.1m

294.50

REGIONAL FLOOD LEVEL

NORMAL LAKE LEVEL

70 m

19m

02A

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02B 02

A

0m 105 5 15

EXISTING CONCRETE WALKWAY

EXISTING ARMOUR STONEAND BOULDER STRUCTURE.

600 mm Ø CSPTEMPORARY CULVERT

50-150mm Ø COBBLE PLACEDTO BE LEVEL WITH ADJACENTLAKE BOTTOM (TYP.)

TURBIDITY CURTAIN

5.6m

±

BOX LOCATIONS

PILE LOCATIONS

B11 2

34

NO CORNER NORTHING EASTINGB1 1 4867462.42 625996.94

2 4867465.69 625994.953 4867467.32 625997.644 4867464.05 625999.63

B2 1 4867468.99 625993.092 4867472.41 625991.363 4867473.83 625994.164 4867470.41 625995.89

B3 1 4867475.87 625989.752 4867479.43 625988.343 4867480.59 625991.264 4867477.03 625992.67

B4 1 4867482.97 625987.042 4867486.61 625985.863 4867487.59 625988.844 4867483.94 625990.03

B5 1 4867491.04 625983.082 4867503.25 625980.623 4867515.77 625980.484 4867516.20 625984.555 4867503.74 625984.846 4867491.43 625987.15

B6 1 4867520.58 625982.272 4867524.39 625982.683 4867524.06 625985.804 4867520.25 625985.40

B7 1 4867528.11 625983.202 4867531.90 625983.843 4867531.38 625986.934 4867527.60 625986.30

B8 1 4867535.60 625984.702 4867539.32 625985.663 4867538.53 625988.704 4867534.82 625987.74

B9 1 4867542.95 625986.802 4867546.56 625988.083 4867545.51 625991.044 4867541.90 625989.76

P3

NO CUTOFF ELEVATION NORTHING EASTINGP1 4867452.78 626006.15P2 4867458.64 626001.47P3 4867464.87 625997.29P4 4867471.41 625993.63P5 4867478.23 625990.51P6 4867485.28 625987.94P7 4867492.17 625984.40P8 4867492.54 625986.01P9 4867499.59 625982.49P10 4867499.90 625984.63P11 4867507.22 625981.70P12 4867507.35 625983.85P13 4867514.87 625982.06P14 4867514.85 625983.68P15 4867522.32 625984.04P16 4867529.75 625985.07P17 4867537.07 625986.70P18 4867544.23 625988.92P19 4867551.19 625991.71P20 4867557.90 625995.06

295.59295.28295.13295.13295.13295.13295.13295.13295.13295.13295.13295.13295.13295.13295.13295.13295.13295.13295.23295.42

Scale 1:1000 SITE PLAN

SPECIFICATIONS:

1. Filter Fabric Material: 1.1 Geotextile shall be non-woven pervious, inert and durable. The material shall be Terrafix 800R or approved equal. Provide a minimum of 800 mm overlap width in the across direction when placing a new section of filter fabric adjacent to

a previously placed section. Repair any damaged filter fabric by placing second layer, overlaying the damaged area by not less then 1500 mm in all directions beyond the damaged area.

1.2 Geogrid shall be Biaxial Geogrid BX1500 by Tensar, or approved equal. Install per manufacturers instructions.

2. 50mm Clear Stone as per OPSS 1004.

3. Top soil as per OPSS 802. Sod as per OPSS 571.

4. Turbidity curtain as per OPSS-219.260 AND 219.261.

5. All concrete shall be in accordance with CSA CAN3-A23.1-04 and CAN3-A23.2-04 Class C-1 (35MPa concrete @28 days). Allreinforcing bars shall be to CSA G30.18 with 400MPa min. yield strength.

6. All steel bars, plates, and shapes shall be new, free from rust and meet the requirements of CSA G40.20/G40.21 M350 W.unless otherwise specified. All bolts, buts, and washers shall meet the requirements of ASTM A325. All welds, weldingequipment, procedures, etc. shall conform to CSA W59-03. Welding shall only be undertaken by a company approved by theCanadian Welding Bureau to the requirements of CSA W47.1, Division 1 or 2, Certification for companies for Fusion Welding ofSteel Structures. Use electrode W480XX. Welding of steel reinforcement bar shall conform to CSA W186-M1990 (R2002). Steelsheet pile wall sections shall be CMRM Z75 or approved equal. Type of steel shall be CSA G40.21 Gr. 350W. Steel round pilesas per OPSS 903.

7. Engineered fill to be non reinforced concrete or clear stone.

8. Cobble stone shall be hard dense, round, cobble stone, mostly igneous rock, free from seams, cracks or other defects. Relativedensity 2.5 to 2.8. Crushed stone will not be permitted. Size to vary from 50-150 mm. Material shall be well-graded between thespecified size limits and contain no fines. Contractor must provide certification of cobble stone material gradation by approvedtesting laboratory when requested by the Engineer. Sample to be provided to Engineer for review.

Scale 1:250 DETAILED SITE PLAN plan

KEY MAP - N.T.S.

TENDER No.CHECKED

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SITE

NOTE:CONSTRUCTION ACCESS ALONGSUNSET BEACH ROAD AND PARKWALKWAY

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EXISTING WALKWAY4m±


TURBIDITY CURTAIN

TEMPORARY CONSTRUCTIONACCESS BERM 50 mm Ø CLEARSTONE TO BE REMOVED UPONCOMPLETION OF WORK

BOARDWALK,DESIGNED BY OTHERS

EXISTING VEGETATEDBANK TO BE RESTORED IFDISTURBED


EXISTING LAKEBED(VARIES) 294.00m±

295.0m ±5m

GEOTEXTILE

STEELTUBE PILE 323 mm Ø,(323.9X12.7 mm)

STEEL SHEET PILE ENCLOSURECMRM Z75 OR APPROVED EQUALSEE DETAIL TYPE 1

CAST-IN-PLACE CONCRETEBLOCK, SEE DETAIL TYPE 1

PLACE 400mm THICK, 50-150 mm ØCOBBLE OVER CONCRETE BLOCK TOBE LEVEL WITH EXISTING LAKE BOTTOM

294.8m

296.0m

287.0±m

4001000

EXISTING VEGETATEDBANK TO BE RESTOREDIF DISTURBED

EXISTING VEGETATEDBANK TO BE RESTOREDIF DISTURBED

TEMPORARY CONSTRUCTION ACCESSBERM 50 mm Ø CLEAR STONE TO BEREMOVED UPON COMPLETION OF WORK

295.0m ±5m

TURBIDITY CURTAIN

BOARDWALK,DESIGNEDBY OTHERS


294.5m NORMAL LAKE LEVEL

STEEL TUBE PILE 323 mm Ø,(323.9X12.7 mm) WITHDRIVING SHOE AND FILLEDWITH CONCRETEAS NEEDED

296.0m

283.0±m

BOARDWALK,DESIGNED BYOTHERS


STEELTUBE PILE 323 mm Ø, (323.9X12.7 mm)

STEEL SHEET PILE ENCLOSURE CMRM Z75 ORAPPROVED EQUAL SEE DETAIL TYPE 2

CAST-IN-PLACE CONCRETE BLOCK,SEE DETAIL TYPE 2

PLACE 400mm THICK, 50-150 mm Ø COBBLE OVER CONCRETEBLOCK TO BE LEVEL WITH EXISTING LAKE BOTTOM

294.8m

296.0m

287.0±m

4001000

SECTION

SECTION

SECTION

CUT STEEL SHEET PILE TO 300 mm BELOW EXISTINGLAKE BOTTOM ELEVATION AFTER CONSTRUCTION

CUT STEEL SHEET PILE TO 300 mmBELOW EXISTING LAKE BOTTOMELEVATION AFTER CONSTRUCTION

294.5m NORMALLAKE LEVEL

SHEAR STUD CONNECTION,SEE DETAIL

TURBITITYCURTAIN

APPROX 2000

ENGINEERED FILL, SEE GENERAL NOTE 10

GEOTEXTILE

SHEAR STUD CONNECTION,SEE DETAIL

PILE CAP, SEE DETAIL



294.5m NORMAL LAKE LEVEL

GEOTEXTILE GEOGRID

GEOGRID

FILL WITHCONCRETEAS NEEDED

FILLED WITH CONCRETEAS NEEDED

DRIVING SHOE AS PEROPSD 3001.1 TYPE II

C02

B02

A02

283.0±m

283.0±m

5647

25290

STEEL SHEET PILE BOX TYPE 2 DETAILScale 1:100

STEEL TUBE PILE 323.9 X 12.7,TO BE LOCATED IN BOX ACCORDING

TO TABLE OF COORDINATES,SEE SHEET 01

20M J BARS WELDEDTO STEEL SHEET PILE,ONE PER SHEET PILE,SEE DETAIL

15M @ 200 TOP ANDBOTTOM BOTH DIRECTIONS

STEEL TUBE PILEHSS 323mm X 12.7mm,TO BE LOCATEDIN BOX ACCORDING TOTABLE OF COORDINATES

STEEL SHEET PILE Z75OR APPROVED EQUAL

SHEAR CONNECTION,L51X51X9.4, 750 mm LONG,SEE DETAIL

3142

3834

STEEL SHEET PILE BOX TYPE 1 DETAILScale 1:50

20M J BARS WELDEDTO STEEL SHEET PILE,ONE PER SHEET PILE,DETAIL

15M @ 200 TOP ANDBOTTOM BOTH DIRECTIONS

STEEL TUBE PILEHSS 323mm X 12.7mm,TO BE LOCATEDIN BOX ACCORDING TOTABLE OF COORDINATES

STEEL SHEET PILE Z75OR APPROVED EQUAL

SHEAR CONNECTION,L51X51X9.4, 750 mm LONG,SEE DETAIL

5FULL LENGTH

SHEAR CONNECTION DETAILN.T.S

50-150 mm Ø COBBLE

15 M @ 200

293.6m±

15 M @ 200

15 M @ 200 (TYP)

15 M @ 200

15 M J BARS WELDED TOSTEEL SHEET PILE

ENGINEERED FILL ORNATIVE SOIL, SEE SECTION,AND NOTE 10

75mm COVER (TYP.)

750

400 MIN

1000

SHEAR CONNECTIONL51 X 51 X 9.4, 750mm LONG

VARIES (SEE BOARDWALK DRAWINGS)

PL 350 mm Ø X 12mmCENTERED ON PILE

DESIGNED BY OTHERS,SEE BLACKWELL DRAWINGS

DESIGNED BY OTHERS,SEE BLACKWELL DRAWING

PILE CAP DETAILN.T.S

BOARDWALK,DESIGNED BY OTHERS

"J" BAR DETAILScale 1:25

300

514

300

300

Z75

5

plan

KEY MAP - N.T.S.

TENDER No.CHECKED

DRAWN DESIGNED

APPROVED

DRAWING TITLE

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plan

KEY MAP - N.T.S.

TENDER No.CHECKED

DRAWN DESIGNED

APPROVED

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PROJECT NAME

DRAWING No.

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APPENDIX II. SEDIMENT FENCE BMP

DesignThe three principal aspects of silt fence design are: proper placement of fencing, adequate amount of fencing, and appropriate materials.

Proper Placement of FencingPlacement is important because where a fence starts, runs, and ends is critical to its effectiveness. Improper placement can make the fence a complete waste of money. Analyze the construction site’s contours to determine the proper placement. Segment the site into manageable sediment storage areas for using multiple silt fence runs. The drainage area above any fence should usually not exceed a quarter of an acre. Water flowing over the top of a fence during a normal rainfall indicates the drainage area is too large. An equation for calculating the maximum drainage area length above a silt fence, measured perpendicular to the fence, is given in Fifield, 2011. Avoid long runs of silt fence because they concentrate the water in a small area where it will easily overflow the fence. The lowest point of the fence in Figure 4 is indicated by a red arrow. Water is directed to this low point by both long runs of fence on either side of the arrow. Most of the water overflows the fence at this low point and little sediment is trapped for such a long fence.

Purpose and DescriptionThe purpose of a silt fence is to retain the soil on disturbed land (Figure 1), such as a construction site, until the activities disturbing the land are sufficiently completed to allow revegetation and permanent soil stabilization to begin. Keeping the soil on a construction site, rather than letting it be washed off into natural water bodies (e.g., streams, rivers, ponds, lakes, estuaries) prevents the degradation of aquatic habitats and siltation of harbor channels. And not letting soil wash off onto roads, which readily transport it to storm sewers, avoids having sewers clogged with sediment. The cost of installing silt fences on a watershed’s construction sites is considerably less than the costs associated with losing aquatic species, dredging navigation channels, and cleaning sediment out of municipal storm sewers.

A silt fence is a temporary sediment barrier made of porous fabric. It’s held up by wooden or metal posts driven into the ground, so it’s inexpensive and relatively easy to remove. The fabric ponds sediment-laden stormwater runoff, causing sediment to be retained by the settling processes. A single 100 foot (ft) run of silt fence may hold 50 tons of sediment in place. Most construction sites today do have silt fences. But many do not work effectively because they are not well designed, installed, or maintained. The focus of this fact sheet is—how to make silt fences work.

Minimum MeasureConstruction Site Stormwater Runoff Control

SubcategorySediment Control

Figure 1. Silt fence retaining sediment

Figure 2. Create manageable sediment storage areas

Figure 3. Water should not flow over the filter fabric during a normal rainfall

Figure 4. Avoid long runs of silt fence

Office of Water, 4203Mwww.epa.gov/npdes/pubs/siltfences.pdf www.epa.gov/npdes/stormwater/menuofbmps

Stormwater Best Management Practice

Silt Fences

EPA 833-F-11-008 April 2012

Stormwater Best Management Practice: Silt Fences

2

Use J-hooks as shown in Figures 5 and 6, which have ends turning up the slope to break up long fence runs and provide multiple storage areas that work like mini-retention areas. If the fence doesn’t create a ponding condition, it will not work well. The silt fence in Figure 7 doesn’t pond water or retain sediment. Stormwater will run around the fence carrying sediment to the street, which will transport the water and its sediment load to the storm sewer inlet.

Water flowing around the ends of a silt fence will cause additional erosion and defeat its purpose. The bottom of each end of the fence should be higher than the top of the middle of the fence (Figure 8). This insures that during an unusually heavy rain, water will flow over the top rather than around either end of the fence. Only fine suspended material will spill over the top, which is not as harmful as having erosion at the ends. When there is a long steep slope, install one fence near the head of the slope to reduce the volume and velocity of water flowing down the slope, and another fence 6–10 ft from the toe of the slope to create a sediment storage area near the bottom. A common misconception is that you only have to worry about water running off steep slopes. However, steep slopes may have a relatively small water collection area. The total drainage area

of a gentle slope, if large (Figure 10), can be more important than its slope in determining sediment loss. A silt fence should not be placed in a channel with continuous flow (channels in Figures 8 and 9 don’t have a continuous flow), nor across a narrow or steep-sided channel. But when necessary a silt fence can be placed parallel to the channel to retain sediment before it enters the watercourse.

Paved streets are major conduits of stormwater and silt, and they drain to storm sewer inlets. The best solution is to retain as much sediment as possible before it reaches paved surfaces. Install a silt fence at the inlet side of a storm sewer or culvert, rather than at the discharge where there is greater velocity and less storage area. Streets cut in the grade, but not yet paved, are also prime erosion conduits. If the streets are not going to be paved right away, they need a containment barrier such as a silt fence. Finally as a construction site’s dynamics change, the silt fence layout should be adjusted when necessary to maintain its effectiveness.

Designers and contractors should also consider diverting sediment-laden runoff water to a sediment detention pond. If the site can provide a large enough area, this is usually the most effective and economical best management practice for retaining sediments. Silt fences are needed when there is insufficient space for a detention pond or when roads and other structures are in the way.

Adequate Amount of FencingThe amount of fencing means the total linear length of the silt fencing runs on the construction site. A reasonable rule-of -thumb for the proper amount of silt fence is—100 ft of silt fence per 10,000 square foot (sq ft) of disturbed area. Soil type, slope, slope length, rainfall, and site configuration are all important elements in determining the adequate silt fence protection for a site, and to what extent it fits the 100 ft per 10,000 sq ft rule-of-thumb. If the amount of fencing provides the volume of runoff storage needed, then over-flowing the silt fence runs will be minimized. This is the basic test; if fences are over-flowing after a moderate rainfall event, the amount of fencing probably needs to be increased to avoid undercutting, washouts, and fence failures.

Figure 5. Use J-hook fences to break up long fence runs

Figure 6. J-hook silt fences provide multiple storage areas

Figure 7. This silt fence doesn’t work

Figure 8. Proper installation, bottom of both ends are above the top of the middle

Figure 9. Poor installation, water can flow around the ends causing additional erosion

Figure 10. Gentle slopes may require a silt fence


3

Appropriate MaterialsThere are different types of porous fabrics available, e.g., woven, non-woven, mono-filament, but all types tend to clog rapidly and don’t provide lasting filtration. The support posts and installation method are more important than the fabric type for overall sediment retention. However, a lightweight fabric tends to tear where it is attached to the posts. Posts must hold the fabric up and support the horizontal load of retained water and sediment. Hardwood posts (2” x 2”) are potentially strong enough to support the loads, but are difficult to drive into the ground more than 6–8”. To hold 2 ft of sediment and water, the posts should be driven 2 ft into the ground. Steel posts are best because they can be driven into compacted soil to a depth of 2 ft. The support posts should be spaced 3–4 ft apart where water may run over the top of the fence, 5 ft in most other areas, and 6–7 ft where there isn’t a considerable horizontal load. Improper post depth and spacing is often the cause of sagging fabric and falling posts. Some authorities believe a more robust wire or chain link supported silt fence is needed to withstand heavy rain events. However, this may double the cost of a silt fence installation and entails disposing of more material in a landfill when the fence is removed. Installing silt fencing having five interacting features: (1) proper placement based on the site’s contours, (2) adequate amount of fencing without long runs, (3) heavy porous filter fabric, (4) metal posts with proper depth and spacing, and (5) tight soil compaction on both sides of the silt fence will usually obviate the need for wire or chain link reinforced fencing. Prefabricated silt fences, e.g., fabric attached to wooden posts in a 100 ft package, doesn’t provide for posting after the ground is compacted or allow variable post spacing.

Silt Fence Installation Two commonly used approaches for installing silt fences are the static slicing method and the trenching method.

Static Slicing MethodThe static slicing machine pulls a narrow blade through the ground to create a slit 12” deep, and simultaneously inserts the silt fence fabric into this slit behind the blade. The blade is

designed to slightly disrupt soil upward next to the slit and to minimize horizontal compaction, thereby creating an optimum condition for compacting the soil vertically on both sides of the fabric. Compaction is achieved by rolling a tractor wheel along both sides of the slit in the ground 2 to 4 times to achieve nearly the same or greater compaction as the original undisturbed soil. This vertical compaction reduces the air spaces between soil particles, which minimizes infiltration. Without this compaction infiltration can saturate the soil, and water may find a pathway under the fence. When a silt fence is holding back several tons of accumulated water and sediment, it needs to be supported by posts that are driven 2 ft into well-compacted soil. Driving in the posts and attaching the fabric to them completes the installation.

Trenching MethodTrenching machines have been used for over twenty-five years to dig a trench for burying part of the filter fabric underground. Usually the trench is about 6” wide with a 6” excavation. Its walls are often more curved than vertical, so they don’t provide as much support for the posts and fabric. Turning the trencher is necessary to maneuver around obstacles, follow terrain contours or property lines, and install upturns or J-hooks. But trenchers

Figure 11. Chain link supported silt fence

Figure 12. Static slicing machine

Figure 13. Tractor wheel compacting the soil

Figure 14. Silt fence installation using the static slicing method

Figure 15. Trenchers make a wider excavation at turns


4

can’t turn without making a wider excavation, and this results in poorer soil compaction, which allows infiltration along the underground portion of the fence. This infiltration leads to water seeking pathways under the fence, which causes subsequent soil

erosion and retained sediment washout under the fence. The white line on the fence in Figure 16 and red arrow both mark the previous sediment level before the washout. Post setting and fabric installation often precede compaction, which make effective compaction more difficult to achieve. EPA supported an independent technology evaluation (ASCE 2001), which compared three progressively better variations of the trenching method with the static slicing method. The static slicing method performed better than the two lower performance levels of the trenching method, and was as good or better than the trenching method’s highest performance level. The best trenching method typically required nearly triple the time and effort to achieve results comparable to the static slicing method.

Proper AttachmentRegardless of the installation method, proper attachment of the fabric to the posts is critical to combining the strength of the fabric and support posts into a unified structure. It must be able to support 24” of sediment and water. For steel posts use three plastic ties per post (50 lb test strength), located in the top 8” of the fabric, with each tie hung on a post nipple, placed diagonally to attach as many vertical and horizontal threads as possible. For wooden posts use several staples per post, with a wood lath to overlay the fabric.

Perimeter Silt FencesWhen silt fences are placed around the perimeter of a stock pile or a construction site, the conventional silt fence design and materials discussed previously may not be sufficient.

Stock pile example. A stock pile of dirt and large rocks is shown in Figures 17 and 18 with a silt fence protecting a portion of its perimeter. Rocks that roll down the pile would likely

damage a conventional silt fence. The bottom of the porous fabric is held firmly against both the ground and base of precast concrete, highway, barriers by light-colored stones. An alternative installation would be having the concrete barriers rest directly on the bottom edge of the filter fabric, which would extend under the barriers about 10”, so the barriers’ weight will press the fabric against the ground to prevent washout. Water passing through the silt fence (red arrow in Figure 18) flows to a storm sewer culvert inlet, which is surrounded by a fabric silt fence (yellow arrows in Figures 17 and 18) that reduces the runoff’s velocity and allows settling before the water is discharged to a creek.

Bridge abutment example. During the construction of a bridge over a river between two lakes, an excavation on the river bank was needed to pour footings for the bridge abutment. The silt fence along the excavation’s perimeter, composed of concrete highway barriers with orange filter fabric, was designed to prevent stormwater from washing excavated spoil into the river and to fend off the river during high flows. A portion of the orange filter fabric that has blown away from the concrete barriers shows the need to overlap and reinforce the joints where two sections of filter fabric are attached.

Highway example. Because of the proximity of a construction site to a highway, a concrete barrier was required by Minnesota’s DOT to protect the highway and an underground fiber optic cable next to the highway from construction activities. The concrete barrier was used to support a silt fence along the perimeter of a large amount of dirt that was stock piled before being used for fill at a different location.

Figure 16. Poor compaction has resulted in infiltration and water flowing under this silt fence causing retained sediment washout

Figure 17. Back of silt fence on part of the stock pile’s perimeter

Figure 19. Silt fence for bridge abutment excavation

Figure 20. Silt fence protecting a highway and underground fiber optics cable

Figure 18. Front of silt fence on part of stock pile’s perimeter


5

Lake shore example. The lake’s shoreline is being restored with plant plugs and seeded with native plant species. A plywood, perimeter, silt fence is used to trap sediment from a construction site on the right-side of the picture, protect the lake shore from

boat-wake erosion, and to prevent geese from eating the seeds and young plants. This fencing will be removed when 70% vegetative cover is achieved.

Inspection and MaintenanceSilt fences should be inspected routinely and after runoff events to determine whether they need maintenance because they are full (Figure 22) or damaged by construction equipment. The ASTM silt fence specification

(ASTM 2003) recommends removing sediment deposits from behind the fence when they reach half the height of the fence or installing a second fence. However, there are several problems associated with cleaning out silt fences. Once the fabric is clogged with sediment, it can no longer drain slowly and function as originally designed. The result is normally a low volume sediment basin because the cleaning process doesn’t unclog the fabric. The soil is normally very wet behind a silt fence, inhibiting the use of equipment needed to move it. A back hoe is commonly used, but, if the sediment is removed, what is to be done with it during construction? Another solution is to leave the sediment in place where it is stable and build a new silt fence above or below it to collect additional sediment as shown in Figure 23. The proper maintenance may be site specific, e.g. small construction sites might not have sufficient space for another silt fence. Adequate access to the sediment control devices should be provided so inspections and maintenance can be performed.

Permanent Soil StabilizationWhen the land disturbing activities are sufficiently completed to allow permanent soil stabilization on the site, the silt fences and sediment basins are removed. The fabric and damaged posts go to the landfill. Steel posts and some of the wooden posts can be reused. Then the sediment is spread over the site to provide fertile soil, and the area can be seeded and mulched to support revegetation.

References ASCE 2001. Environmental Technology Verification Report for Installation of Silt Fence Using the Tommy Static Slicing Method, CERF Report #40565. Washington, DC: American Society of Civil Engineers. www.epa.gov/etv/pubs/08_vs_tommy.pdf

ASTM 2003. Standard Practice for Silt Fence Installation, D 6462-03(2008). West Conshohocken, PA: American Society of Testing Materials International. www.astm.org/SEARCH/search-reskin.html?query=D6462-03&siteType=store-standards&searchType=standards-full

Carpenter, Thomas 2000. Silt Fence That Works. Ankey, Iowa: Thomas Carpenter. www.tommy-sfm.com/pages/resources/Silt%20Fence%20That%20Works%20Manual.pdf

Fifield, Jerald S. 2011. Designing and Reviewing Effective Sediment and Erosion Control Plans, 3rd Edition. Santa Barbara, CA: Forester Press.

U.S. Environmental Protection Agency 2007. Developing Your Stormwater Pollution Prevention Plan, EPA 833-R-06-004. Washington: EPA. Available from EPA hardcopy 800-490-9198 or www.epa.gov/npdes/pubs/sw_swppp_guide.pdf

Photograph CreditsFigures 1–10, 12-16, 22, 23. Thomas Carpenter, CPESC, Carpenter Erosion Control

Figure 11. Pete Schumann, Fairfax County, Virginia, Department of Public Works and Environmental Services

Figure 17–21. Dwayne Stenlund, CPESC, Minnesota Department of Transportation

Figure 21. Silt fence protecting a lake shore

Figure 22. A silt fence full of sediment that needs maintenance

Figure 23. New silt fence below the old fence

DisclaimerPlease note that EPA has provided external links because they provide additional information that may be useful or interesting. EPA cannot attest to the accuracy of non-EPA information provided by these third-party websites and does not endorse any non-government organizations or their products or services.

http://www.epa.gov/etv/pubs/08_vs_tommy.pdf

http://www.epa.gov/etv/fp-evtec.html

http://www.astm.org/SEARCH/search-reskin.html?query=D6462-03&siteType=store-standards&searchType=standards-full

http://www.astm.org/SEARCH/search-reskin.html?query=D6462-03&siteType=store-standards&searchType=standards-full

http://www.tommy-sfm.com/pages/resources/Silt%20Fence%20That%20Works%20Manual.pdf

http://www.tommy-sfm.com/pages/resources/Silt%20Fence%20That%20Works%20Manual.pdf

http://www.fairfaxcounty.gov/dpwes/publications/pfm/ch11_plates.pdf

http://www.epa.gov/npdes/pubs/sw_swppp_guide.pdf



APPENDIX III. EROSION AND SEDIMENT INSPECTION FORM

EROSION AND SEDIMENT CONTROL INSPECTION REPORT

Niblett Environmental Associates 1

SITE INFORMATION

Project Name: Wilcox Lake Boardwalk Inspections Date:

Permit No.: Time:

Contractor: Inspector Qualifications:

Notice Given to: Duration on Site:

Stage of Construction: Date of Last Inspection:

Site Area: Reason for Inspection*:

Receiving Water: Wilcox Lake Current Weather Conditions:

*example of inspection reasons: rainfall event, snowmelt event bi-weekly monitoring etc.

SEDIMENT AND EROSION CONTROL

INFORMATION Yes No N/A ADDITIONAL COMMENTS/ACTION(S)

Do (or can) offsite flows enter the site?

Is there evidence of, or the potential for, increased pollutant (e.g., sediment, fuel, concrete waste, portable

toilet waste, etc.) discharging from the site?

Do installation, repair and/or maintenance of sediment control BMPs need to occur?

Do installation, repair and/or maintenance of erosion control BMPs need to occur?

Do installation, repair and/or maintenance of in-stream BMPs need to occur?

Is there evidence of sediment discharging off the construction site and onto downstream location?

Are vehicles tracking sediment off the construction site?

If applicable, is soil, construction material, landscaping items, or other debris evident on the streets?

Do location exist where consideration of installing additional BMPs identified and shown in the ESC plan

can occur?

Is a photo inventory provided?

Does the site evaluation indicate a need to possibly update and document the ESC plan within the next

seven (7) calender days?

Have all previous inspection items been addressed and documents by the next full work day or within seven (7)

calendar days after an inspection?

EROSION AND SEDIMENT CONTROL INSPECTION REPORT

Niblett Environmental Associates 2

DETAILED REPORT

Identify the problem and its location. If appropriate, describe (in general terms) what need to be completed. However, only if qualified (e.g., you are a designer) should you be

mandating specific BMPs to install

Date Completed (with initials)

Inspectors Name: Signature: Date:

Title/Qualifications of Inspector:

ADDITIONAL COMMENTS

Coversheets - Appendices...55 Mary Street West, Suite 112, Lindsay, Ontario K9V 5Z6 Tel: (705)...

Documents

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