WWPI / WPC/ SPTA / TWC

Impact Assessment Model

Western Wood Preservers Institute Dallin Brooks

NOAA ESA and EFH guidance difficult to interpret and apply to specific projects.

Parks Canada?

Smaller projects need a tool to demonstrate that the use of treated wood in aquatic environments, in many situations, has no significant or measurable impact.

Provides basis for sound environmental review of specific projects by regulatory agency staff.

Why Develop An Environmental Impact Assessment Model?

Preserved Wood in Aquatic Environments

Three Levels Of Assessment

- Level One Screening Assessment - Level Two Intermediate Risk Assessment - Level Three Full Risk Assessment

Foot, Road and Railroad Bridges Boat Docks Marinas and Wharfs Piling Dikes

Examples of Projects Suitable for Level One Screening Assessment

Retaining Walls, Sea Walls, Dolphins Foot, Rail and Road

Bridges w/Abutments

Examples of Projects for Level Two and Three Risk Assessment Model

Purpose Tool to support consistent, objective decisions in

evaluating effects of use of treated wood in aquatic environments

Users Project proponents, action agencies, and reviewing

agencies

Method Utilizes peer-reviewed water quality model output

that has been tabulated and presented in a worksheet for screening simple project

Screening Level Assessment Process & Worksheets

Water-borne preservavtives Ammoniacal Copper Zinc Arsenate

(ACZA) Chromated Copper Arsenate (CCA) Copper Azole (CA- B & C) Alkaline Copper Quat (ACQ) Micronized Copper Quat (MCQ)

Preservatives that can be Assessed

Oil-type preservatives

Pentachlorophenol Creosote Copper Naphthenate

Preservatives that can be Assessed

The Box Model

Immersed treated piling

Water depth (cm)

Box length = length of the structure (cm)

Current Vector Vss or Vmodel

Contaminant concentrations are determined by background concentrations and inputs from the pressure treated wood that are diluted by the water flowing through the box

Contaminant inputs include rainwater runoff from overhead treated wood and direct inputs from immersed treated wood

Contaminant Trajectories

h

Distance from pile = D

Piling

Piling

Contaminant trajectories

Waterline

= 0.5 *Vmodel

Current

Current Vector Settling Velocity

(Vv)

Distribution of Preservative Lost from an Overhead Structure in Rainwater Runoff

Dripline of bridge

20 cm deep initial dilution zone

Sediment dilution zones in cm equals 400*current speed (cm/sec)

Depth (d) -20 cm

Depth (d)

1. “no effect” determination

2. “no effect” determination with specific special conditions

3. “may affect, not likely to adversely affect” determination which may allow informal consultation;

4. “may affect, not likely to adversely affect” with specific special conditions determination can be made which may allow informal consultation;

5. “likely to adversely affect” determination which will require formal consultation.

Model Leads to One of Five Determinations Regarding Consultation

Figure 2: Assessment Framework

Review Categorical Approvals

Level One Screening Assessment

No Effect Determination

Level Two Intermediate Risk Assessment

Level Three Full Risk Assessment

No Effect Determination

Meets Criteria

Meets Criteria

Not Likely to Adversely Affect

Determination

Meets Criteria

No

No

No

Not Likely to Adversely Affect

Determination

Meets Criteria

No Modify Project or

Likely to Adversely Affect Determination

LEVEL 1 ASSESSMENT

ASSUMPTIONS

Level 1 Screening Assessment

Project Information - Design

- Preservative

Site Information - Physical - Chemical - Biological

Lookup Tables Generated by

Leaching Models Next Level of

Assessment Needed

No Effect Determination

Level 2 Intermediate Risk Assessment

Level 3 Full Risk Assessment

OR AND

Figure 3 Level One Screening Assessment

Copper Based Preservatives

Creosote Based Preservatives

Penta Treated Preservatives

Copper Screening

Assessment

Creosote Screening

Assessment

Penta Screening Assessment

Mixed Preservatives

Separate Project

by Preservatives

(See Figure 3-A and

Worksheets 1 or 2)

(See Figure 3-B

and

Worksheet 3)

(See Figure 3-C and

Worksheet 4) (For Copper Overhead Decking and Piling

Treated with Creosote or Penta, see

Worksheet 5)

Level 1 Screening Assessment

Exposure Can Be Assessed for: Submerged piling and overhead decking Overhead Wood Structures (Bridge deck) In Both Marine and Fresh Water

Key Factors For Performing Assessment # of Piling in Row Parallel to Current Square Footage of Project Area Current Speed Redox and pH

Products Treated to Industry BMPs

Project Assessment

PROJECT SCREENING LEVEL ASSESSMENT AND WORKSHEET EXAMPLES

Step 1: Complete Project Information Form Step 2: Preliminary Assessment of Risk (Figure

2, page 15 in Workbook)

Step 3: Complete Assessment Worksheet

SECTION 4: LEVEL ONE PROCEDURES

PROJECT APPLICATION FORM

300’ long x 6’ wide (1,800 sf.) wood deck float 10 piling in row (example dock on right)

SCREENING ASSESSMENT FLOATING PIER EXAMPLE

Marine Application

CCA Piling ACQ Treated Overhead Decking

SCREENING ASSESSMENT FLOATING PIER EXAMPLE

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SITE SPECIFIC DATA

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LEVEL 2 INTERMEDIATE RISK ASSESSMENT

Project Information - Design

- Preservative

Site Information - Physical - Chemical - Biological

Apply Peer-Reviewed Risk

Assessment Models Next Level of

Assessment Needed

No Effect Determination

Level 3 Full Risk Assessment

OR AND

Poston Box model

WWPI Brooks model

LEVEL 2 CONSIDERATIONS

LEVEL 2 CONSIDERATIONS

LEVEL 3 CONSIDERATIONS

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Splash Screen

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Modelling Tool Page – upon first loading

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Modelling Tool Page – inputs entered, water impact results visible

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Modelling Tool Page – inputs entered, preservative drop-down list

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Modelling Tool Page – other inputs, sediment impact results visible

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PDF report export (opens in new tab)

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Log-in Page

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My Accounts Page – access saved sessions

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Modelling Tool Page – saved session loaded (Dallin’s Demo for WPC)

Western Wood Preservers Institute www.preservedwood.org 360-693-9958 39

(Help Content) Input Definitions Page

QUESTIONS AND DISCUSSION

Model To Be Hosted By: Oregon State University Environmental Performance of Treated Wood Co-op Currently at http://wwpi-cms.upshift.co.nz/

CONTACT INFORMATION: Dallin Brooks Western Wood Preservers Institute dallin@wwpinstitute.org 360.823.3898