TagThird Runway(1098)

This research study examines how heavy metals in highway stormwater runoff behave as water flows off pavement, finding that most heavy metals remain dissolved rather than attaching to solid particles due to low alkalinity and short travel times on the pavement surface. The study, conducted on Interstate 75 in Cincinnati over two years, explores how best management practices like detention basins or infiltration trenches could be used to capture these metals before they reach receiving waters.

Reference list compiled by Peter Willing, Ph.D., of documents relied upon in testimony regarding the 401 Water Quality Certification for the Third Runway at Sea-Tac Airport. Sources cited include studies on highway runoff chemistry, heavy metals partitioning, urban stormwater BMPs, treatment wetlands, NPDES permits, and Port of Seattle annual stormwater monitoring reports (1998–2001). Key references

This document is a reference bibliography (Exhibit B) listing scientific and regulatory sources related to environmental monitoring at Seattle-Tacoma International Airport. It includes studies on stormwater quality, aircraft de-icing and anti-icing fluid toxicity, aquatic habitat assessment, and sediment guidelines, drawn from sources such as the Port of Seattle, Parametrix Inc., and various environmental agencies. The references support environmental compliance reporting under the airport's NPDES stormwater permit.

This document outlines wetland mitigation calculations for the Vacca Farm site, detailing compensation actions such as wetland restoration and enhancement across various locations including Lora Lake and prior converted croplands. Adjustments were made to credit acreages based on state ecology findings and documentation gaps; for example, the 6.60-acre converted cropland credit was reduced to 3.30 acres because the state identified those areas as existing wetlands requiring enhancement ratios rather than restoration ratios. In total, the site's original 10.48 credit acres were adjusted down to 5.61 acres after accounting for these regulatory and documentation considerations.

This document is a 30% design submittal prepared by HNTB Corporation for the Third Runway Embankment Construction Phase 4 project at Seattle-Tacoma International Airport. It is an oversized engineering exhibit, submitted without a date, representing an early-stage design milestone in the ongoing construction of the airport's third runway. The submittal is part of the administrative record (AR 025787) related to the runway expansion project.

This document outlines the Port of Seattle's step-by-step process for applying water quality standards at a specific site, focusing on copper toxicity testing in local waterways. The flowchart guides researchers through a series of studies — including screening, range-finding, and definitive toxicity tests using waterfleas and fathead minnows — to determine whether copper levels in outfall and receiving waters pose environmental risks. Depending on test results and regulatory approval from the Washington State Department of Ecology, the process may lead to a Water Effect Ratio (WER) study or a Translator Study.

This document presents a Water Resources Analysis Schedule, displayed as a Gantt-style project timeline chart. It outlines the sequencing and duration of various technical tasks related to water resources analysis, including data collection, feasibility studies, treatment evaluations, and report preparation. The schedule appears to track project milestones and dependencies across multiple phases of a water resources planning effort.

This document outlines Washington State Department of Ecology's presumed policy positions on stormwater mixing zones, addressing when stormwater becomes regulated state water and how mixing zones should be calculated. It details recommended design storms for acute and chronic mixing zones, critical receiving water flow conditions, and background concentration requirements. The document also discusses circumstances under which mixing zone size criteria exceedances may be permitted under state regulations.

This document contains hydrological flow data for Miller Creek, including a ranked frequency analysis of the lowest monthly mean streamflows recorded between August and May from 1948 to 1995, alongside modeled daily and hourly stream flow outputs from 2-year/72-hour and 2-year/2-hour storm events simulated in August 1996. The analysis identifies a 5-year mean low flow of approximately 0.60 cubic feet per second for the lowest month in the August–May period. Acute and chronic water quality standards are also evaluated in relation to effluent and receiving water flows during the storm event.

This document presents a statistical analysis of ambient water conditions and effluent discharge at a location designated 3RWN, examining the joint probability of stream flow and discharge occurring simultaneously. It includes a 3D probability surface chart, a data table showing dilution factors ranging from 3.6 to 5,294 at various probability levels, and a distribution curve of ambient stream discharge measured in cubic feet per second. The analysis notes that effluent is present approximately 38% of the time, with the 7Q10 flow of 0.16 cfs corroborating the 1st percentile and the 5Q30 flow of 0.15 cfs corroborating the 0.9th percentile.