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The Alaskan Way Viaduct and Seawall Project – Environmental Challenges and Opportunities. Scott Woerman David Hill Mike Flowers. If We Do Nothing…. Overview. Viaduct and Seawall History Design Options Economics and Funding Environmental Streamlining Permits and Environmental Review
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The Alaskan Way Viaduct and Seawall Project – Environmental Challenges and Opportunities Scott Woerman David Hill Mike Flowers
Overview • Viaduct and Seawall History • Design Options • Economics and Funding • Environmental Streamlining • Permits and Environmental Review • Challenges and Opportunities
Viaduct and Seawall History • One of two north-south arterials • Built for 65,000 vehicles per day – today handles 110,000 vehicles daily • WSDOT Identified viaduct as being vulnerable to earthquakes
The Seawall – Early Days • Built in 1934 • Constructed in 3 Phases • Backfilled with undocumented materials
The Viaduct – Early Days • Construction took place between 1949 – 1953 • Too Rigid • Prone to Failure
Viaduct & Seawall - Threats • Gribbles • Earthquakes
Design Plan Options • Two phases of design options • Phase 1 had 3 potential alternatives • Phase 2 has 2 hybrid alternatives
Phase 1 – Tunnel Plan • Two types of tunnel construction: • Cut & Cover • Bored/Mined • Both tunnel methods will encounter dewatering challenges
Cut & Cover • Dig huge open trench • Build tunnel: pre-made or build in place • Back fill tunnel • City construction difficult • buildings • roads • utilities
Bored/Mined • Tunnel Boring Machine (TBM) assembled on-site • Steel cutters chip off pieces of rock/soil • 50 feet per day • No noise heard on surface
Aerial Design Option • Replace existing structure with new viaduct • Larger viaduct with more traffic lanes • Earthquake resistant • Not favorable
Rebuild Design Option • Repair & retrofit existing viaduct • rebuild seawall • Holgate to Battery Street tunnel • Upgrade fire/life safety in Battery Street tunnel • Cheapest Alternative • Lowest life expectancy
Phase 2 Designs • Leadership group preferred Tunnel option but it was too expensive at $10 billion. • Boulevard / Tunnel Combo Options • Combo 1: side by side tunnel with 4 lanes and 6 boulevard lanes • Combo 2: side by side tunnel with 8 lanes and 4 boulevard lanes • Reduces costs by over 50% • Final selection due year-end 2004
Economics & Funding • Who’s paying for it? You are!! • $15 Million for next 2 years • Actual construction: Cost Duration Tunnel Plan $3.9 - $4.7 Billion 7-9 years Aerial Plan $2.7 - $3.3 Billion 6-8 years Rebuild Plan $2.4 - $2.9 Billion 8-9 years
Environmental Streamlining • Generally associated with transportation projects • Goals: - Facilitate timely execution of projects - Continued environmental protection - Utilize efficient agency resources - Develop consistent standards - Avoid redundant efforts
Federal Streamlining • Section 1309 of the Transportation Equity Act for the 21st Century (aka TEA-21) • Mostly applicable in NEPA review process • USDOT signed national Memorandum of Understanding (MOU) with 6 other agencies to implement Section 1309
Streamlining in Washington State • Environmental Streamlining Act (2001) • Created Transportation Permit Efficiency and Accountability Committee (TPEAC) • Oversees “transportation permit reform that expedites the delivery of statewide significant transportation projects through a streamlined approach to environmental permit decision making”
Streamlining in Washington State • TPEAC Products: - Subcommittees - Applied to pilot projects and projects of statewide significance • Joint Aquatic Resources Permit Application (JARPA)
Permits and Environmental Review • Process Flow - Permitting authority receives and reviews permit application - Draft permit or notice of intent to deny is issued - Public comment period provided - Final determination
NEPA/SEPA • NEPA/SEPA Triggers • NEPA and SEPA review will be addressed concurrently • WSDOT, City of Seattle, and FHWA are joint lead agencies for NEPA/SEPA Review • Currently developing draft EIS expected winter 2003
Historic Preservation • National Register of Public Places • Section 106 of the National Historic Preservation Act of 1966 • Section 4(f) of the Department of Transportation Act of 1966 • Requirements will be addressed in the NEPA/SEPA process in the draft EIS
Hydraulic Permit Approvals • Washington State Department of Fish and Wildlife has authority • State law known as the Hydraulic Code (1949) eventually led to the requirement that “that any person, organization, or government agency wishing to conduct any construction activity in or near state waters must do so under the terms of a permit called the Hydraulic Project Approval”
Section 401 Water Quality Certification • Federal Clean Water Act provision • Washington State Department of Ecology has authority • Required before issuing a license or permit that may result in any discharge to waters of the United States • Section 401 certification required before: • 404 permits from the Corps of Engineers • EPA-issued NPDES permits.
Section 404 • Administered by the ACOE and EPA • “…monitors the discharge of dredged or fill materials to the waterways of the United States…” • Two types: - General Permit - Individual Permit
Section 404 cont’d • Highly controversial • Expected to be the most difficult to obtain • Lessons from Port of Seattle’s 3rd Runway
Shoreline Substantial Development • WA Shoreline Management Act - King County - City of Seattle • Project will - Impact marine waters - > 20 acre water body - Within 200 ft. of upland areas
CWA: NPDES • Federal Clean Water Act regulates discharges to water bodies through NPDES Permit system • Includes stormwater runoff • Construction activities regulated separately under general permit • Requires site to develop SWPPP and implement BMPs • When construction is complete, stormwater will be regulated by King County’s Individual NPDES Permit that covers the Cedar/Green Water Quality Management Area (City of Seattle included)
Water Quality Most publicized and debated Elliot Bay is 303(d) listed body of water (CWA) Construction to last 7-9 years and could have significant impacts if left unchecked Noise Excavation Equipment Dump Trucks Mitigation Measures Haul Routes Mufflers Construction scheduling Boring method generates less surface level noise Environmental Challenges
Aesthetics Assimilation of viaduct into surrounding environment Become part of Seattle atmosphere Tunnel option will have minimal impacts to viewsheds Input from community Hazardous Materials Unanticipated and costly impacts Waste generated from construction Contaminated soil and water comprising the seawall Disposal of excavated soil and dewatering waste Environmental Challenges
Energy - Construction No Significant Impacts Equipment to use external power sources Energy – Post Construction Lighting Ventilation System Emergency call boxes DOT Cameras Control Facility Environmental Challenges
Environmental Challenges Air Quality • Fugitive dust emissions - Demolition - Construction • Construction equipment exhaust
Environmental Opportunities Environmental Streamlining • Opportunity to prove that public transportation funding can be used efficiently and effectively • Public expectations and policies often conflict with one another: • Environmental protection • Rapid transportation solutions • Streamlining is the solution
Environmental Opportunities Water Quality • Enhanced stormwater management: • New conveyance utilities • Retention reservoirs / settling ponds • Treatment facilities • Contaminant source control/removal
Aesthetics Connect waterfront with downtown Seattle Construct walkways Develop small parks Utilities Construct utilidor Improve utility infrastructure Reduce costs Environmental Opportunities