Developing Risk Assessment and Writing Performance-Based Specifications Alaska Department of Transportation By Kurt S. Chirbas, PE Profile Products

Items that designers, contractors and inspectors must address Risk Type Soil Stabilization (Passive) Sediment Containment Erosion Control Dust Control Stormwater Compliance Establishing Vegetation New EPA Rules (NTUs - Numerical base numbers)

What is the Risk level of your project? Risk level identification will help you specify the performance requirements of the soil stabilization, erosion control and revegetation technologies.

Critical Areas that Influence Risk Level Wetlands Streams Ponds Rivers Creeks Drainage swales Wildlife habitat

Other Factors that Influence Risk Level Seasonal weather conditions Soil types Amount of earth moving Duration of project Site conditions (slopes, drainage patterns, etc) Many other factors

Risk Level Influence (regulations) can come from: EPA State Agencies County City Special Interest Groups Political Pressure

Risk Level Assessment Should Include Site Evaluations During: Design stage Developing the SWPPP Construction phase Post Construction Risk level is a process that continues throughout the project. It Is Not An Event.

To Determine the Numerical Value of Sediment Loss Risk, use the : Revised Universal Soil Loss Equation (RUSLE) A = R x K x L x S x C x P

RUSLE, continued Items that you cannot control: R = rainfall factor (site or area specific) K = soil erodability factor (based upon soil types) Items that you can control: L = slope length factor S = slope steepness factor P = Practice Factor (surface roughness) C = vegetation or cover factor (performance of soil stabilization product)

Web-Based and Free Design Software for Erosion Control and Soil Stabilization

Profile Soil Solutions Software www.profileps3.com Now that you have seen a couple case studies, how about an understanding of the technical services that went into selecting the right products for the project? “In the Ground, On the Ground and By Your Side”

Project Basics - Slopes Input the necessary information to determine the most appropriate Profile Products for your slope project. Click Save and Calculate As a reminder, click on any of the “?” to get more information.

Stormwater Runoff Quality is Another Risk to be Determined and Governed by: US Army Corp of Engineers State Fish and Game Department of Natural Resources Specification writers should insist that manufacturers provide performance test data including turbidity, pH and eco-toxicity.

Risk Level Identification Summary: Little control over Critical areas (wetlands, creeks, etc) Wildlife habitat (fish, etc) Soil types (erosive or non-erosive) Weather Control over Drainage Patterns Potential soil loss Duration of project Specification and performance requirements Compliance issues Turbidity and pH Ensure products have environmental testing (Ecotoxicity data) Erosion & Soil Stabilization Revegetation

Writing Performance-Based Specifications

What Specifications are used for: Engineer – in conjunction with drawings, used to explain requirements to construct the project, including: environmental, performance and physical requirements Contractor – for bidding and ensuring he meets the intent of the project Inspector – to verify that correct materials were used and installation was correctly done Owner – to ensure they receive what they THINK they will receive Attorney – documents to show that someone was negligent Agencies – ensuring you stay in compliance

Specification Properties: (Use ASTM or industry standards whenever possible) Performance Properties – how does it perform (examples: erosion control, functional longevity, vegetation establishment, wet bond strength, etc.) Environmental Properties– does it impact water quality/wild life, etc Physical Properties – Helps the inspector in the filed for verification for approval (examples: thickness, weight, coverage percent) and also used for quality control for manufacturer

What Should be Expected From Specifications: The maximum level of effort by the contractor (but not a $ more) The minimum that the Resident Engineer and owner’s rep will accept (nothing less)

Functional Requirements for HECPs, ECBs, Soil Builders, etc to be Included in Specifications a. Environmental: must not impact water quality or wildlife habitat b. Erosion Prevention Effectiveness c. Effectiveness of seed germination and vegetation establishment d. Functional Longevity

HECP, ECBs, etc Categories Should be Based on Functionality a. Performance Properties b. Environmental Properties c. Physical Properties d. Installation restrictions e. Field Verification

Factors for Design Engineer to determine what HECP category to use on a Project Slope Angle and Slope Length Soil type Climate conditions Time of year of seeding Time required to establish vegetation Water Quality Parameters Sensitive Surrounding areas of the project Application Restrictions (such as precipitation events, wet soil, temperature) Functional longevity of performance Effectiveness of erosion protection

“The Green Engineering Triangle” Example of Writing a Performance-Based Specification for HECPs Functional Longevity Growth Establishment Erosion Control Effectiveness Establishing vegetation requires balancing NATURAL VARIABLES and PRODUCT BENEFITS to create the best environment for sustainable erosion control Water Vegetation Soil “The Green Engineering Triangle”

Performance Testing of HECPs Cover Factor – Large Scale Testing Wet Bond Strength – ASTM D6818 Functional Longevity – ASTM D5338 Growth Establishment – ASTM D7322 Water Holding Capacity – ASTM D7367

Environmental Testing of HECPs Phytosanitization – USDA Protocol Biodegradability – ASTM D5338 Ecotoxicity – EPA 2021.0 Effluent Turbidity – Large Scale Testing

General Specifications Example – Hydraulically-Applied Erosion Control: 1.01 SUMMARY This section specifies a hydraulically-applied, 100% biodegradable, Bonded Fiber Matrix (BFM) that is manufactured in the United States and is composed of 100% recycled Thermally Refined™ wood fibers and naturally derived crosslinked biopolymers. The BFM may require a 24-48 hour curing period to achieve maximum performance. The BFM is phytosanitized, free from plastic netting, and when cured forms an intimate bond with the soil surface to create a continuous, porous, absorbent and flexible erosion resistant blanket that allows for rapid germination and accelerated plant growth. Use BFM as an allowable mulch for a temporary soil stabilization cover by mulch, temporary cover by seeding or permanent cover by seeding applications. Do not use BFM as a channel liner or for areas receiving concentrated flow. Install BFM in the following situations: Can be used as an equal to a double net straw blanket. When required observed functional longevity of soil protection is a minimum of 210 days. When soil is dry and rain is not expected within a minimum of 24 hours after application. Related Sections: Other Specification Sections, which directly relate to the work of this Section include, but are not limited to the following: Section 01 57 00 – Temporary Erosion and Sediment Control Section 31 00 00 – Earthwork Section 31 91 00 – Planting Preparation In environmentally sensitive wetlands and other wildlife areas not compatible for products containing netting.

Continued … 2.02 MATERIALS   The HECP shall be MBFM and conform to the following property values when uniformly applied at a rate of 3500 pounds per acre (3900 kilograms/hectare) under laboratory conditions. Physical Property (Quality Control for manufacture, physical verification in the field) Performance Values Protection Against Erosion Functional Longevity Environmental Protection Values Water Quality/Environmental .

Continued … 2.05 QUALITY Quality Assurance   Quality Assurance Provide the following information from the manufacturer: Written quality control program conforming to the requirements of subsection 1.2.2 Quality Control…. 3.0 INSTALLATION (Explain how you want it to be applied in addition to manufacture requirements) Use BFM where all components are pre-packaged by the manufacturer to assure material performance. Do not field …. 3.1 Application Rates: These application rates are for standard conditions. Designers may wish to reduce rates to encourage faster vegetation establishment …

Continued … Inspection and Maintenance Prepare a BFM maintenance plan that includes the following: Reapplication of BFM as directed …. Reapplication is not required unless BFM treated soils are disturbed or turbidity or water quality shows the need for an additional application. I   Acceptance Obtain Resident engineer/owner representative acceptance and approval of BFM installations. When requested by the Resident engineer/owner representative that a manufacturer’s representative is on-site to oversee and approve the initial BFM installation. At the request of the resident engineer or owner representative, the contractor will perform a sample field application of the hydraulic mulch at the specified rate within the specifications prior to applying the hydraulic mulch to any

Sample of HECP Performance Base Specification

BFM, Bonded Fiber Matrix FGM Correctly Installed and met project specifications

FGM Incorrectly Installed, but still met project specification

Perform a Sample Field Application At the request of the resident engineer or owner’s representative, the contractor will perform a sample field application of the hydraulic mulch or erosion control product at the specified rate prior to applying the hydraulic mulch to any other part of the project.

Field Mixing vs. Pre-Packaging of Mulch Products Field Mixing: Adding all the ingredients to make the desired mulch product in the field (mulch, tackifier , polymers, etc). This could lead to inconsistent product performance using a variety of different manufacturers’ products. This also usually leads to an absence of actual test data to ensure performance criteria can be achieved in the field. Pre-Packaging: Automated blending of the ingredients at prescribed rates and packaging it for shipment at the manufacturing plant. This method leads to consistent product performance and manufacturer can provide independent performance test data to validate the product’s performance.

Example of a questionable specification

No performance values – Functional Longevity, Cover Factor, Application restrictions, Environmental requirements, etc.

Summary for a successful project (meeting regulations, minimize change orders meeting the overall objectives of the project, minimize construction delays) Know your regulation requirements Determine your Risk Level (sediment, erosion and water quality requirements) Write specification specific for your project (Performance, Environmental, Physical properties) Make sure contractors submittals are accurate with supporting manufacture testing data for the product to be used Ensure material was installed correctly Thank you!