TagNPDES(130)

This is the Annual Stormwater Monitoring Report for Seattle-Tacoma International Airport, covering the period from July 1, 1998 through June 30, 1999, prepared by the Port of Seattle. The report documents water quality sampling results from airport storm drainage systems, including measurements of petroleum hydrocarbons, metals, fecal coliforms, and the effects of aircraft and ground deicing activities on runoff. It includes data summaries, outfall inspections, and source tracing studies aimed at tracking and managing stormwater pollution from airport operations.

Annual stormwater monitoring report (AR018047) prepared by Port Of Seattle for Seattle-Tacoma International Airport (STIA) covering the period July 1, 1998 through June 30, 1999. Documents NPDES stormwater sampling results across STIA storm drainage subbasins including grab and composite samples for total petroleum hydrocarbons (TPH), fecal coliforms, suspended solids (TSS), turbidity, biochemical oxygen demand (BOD5),

A 1999 internal technical memo from Parametrix, Inc. evaluates three alternative water-quality dilution modeling methods for assessing whether proposed stormwater outfalls at the Port of Seattle could exceed Washington State water quality standards. The methods range from a static single-event approach based on Ecology's Permit Writer's Manual to a dynamic continuous simulation using HSPF hydrologic models and a probabilistic EPA-funded model developed by researcher Dominic Di Toro. The memo recommends continuing with the continuous simulation approach while considering budget, Ecology's involvement, and the nature of ambient and effluent pollutant concentration data.

This document is a section of Washington State's Permit Writer's Manual covering Water Effect Ratio (WER) methodology for water quality permitting. It outlines procedures for determining how receiving water conditions affect the toxicity of discharged effluents, including required toxicity testing species, sampling schedules at critical and non-critical flow conditions, and guidelines for freshwater and saltwater discharge situations. The document is unrelated to Sea-Tac Airport noise policy.

Exhibit 2110, AR 033718. Internal Washington State Department of Ecology email chain dated May 14, 1999, among Kevin Fitzpatrick, Tom Luster, Raymond Hellwig, Paula Ehlers, Erik Stockdale, Wendy Bolender, Lisa Austin, John Glynn, and Bill Moore regarding the 401 Certification and NPDES permit matrix for the Sea-Tac Airport Third Runway project. Key issues include stormwater

This 1999 email chain between Washington State Department of Ecology officials discusses the 401 Water Quality Certification process for a major Port of Seattle project affecting Des Moines and Miller Creek watersheds near Sea-Tac Airport. Key disputes include stormwater discharge compliance with water quality standards, required mitigation measures such as riparian buffers and stream flow augmentation, and the retrofitting of existing stormwater outfalls. Officials warn that the creeks are already hydrologically impaired, with flood and erosion conditions far exceeding pre-development levels, making it difficult to approve the project without a comprehensive and specific mitigation package.

These handwritten meeting notes dated 5/10/99 document a discussion among water quality staff including Kevin Fitzpatrick and Gary Bailey regarding permit standards and guidance. Topics covered include updating water quality standards to 'use-based' classifications, finalizing antidegradation rules, and establishing sampling protocols such as requiring at least 5 days of sampling during critical low-flow conditions. The notes also address mixing zone limits, AKART conditions for permit outfalls, and revisions to the permit writer's manual expected by June or July.

This is a Procedure Manual for stormwater monitoring at Sea-Tac International Airport, developed by Port of Seattle Environmental Services to comply with NPDES Permit WA-002465-1. It outlines sampling locations, monitoring schedules, deicing event protocols, and quality assurance procedures for collecting and reporting stormwater data. The manual covers topics ranging from automatic and manual sampling methods to laboratory accreditation and discharge monitoring report requirements.

This 1999 email chain between Washington State Department of Ecology staff discusses the challenges of applying water quality standards to stormwater discharges related to the proposed Sea-Tac Airport third runway project. Officials from the Water Quality and Shorelines/Environmental Assistance programs agreed that strictly enforcing numeric water quality criteria on stormwater is scientifically and legally difficult, and recommended an 'adaptive management' approach requiring monitoring and ongoing improvements rather than immediate full compliance. The correspondence also highlights resource limitations, the relationship between Section 401 and 402 Clean Water Act permits, and the need for a consistent statewide policy on stormwater review.

In this January 1999 email, Dave McBride of Parametrix, Inc. responds to questions from Brian Pippin about the Manke project, clarifying that the Washington State Department of Ecology had not yet reviewed the draft report and that the client was intentionally delaying the process to gain more time. He also notes that the use of a 6-month, 24-hour storm standard was a requirement of the NPDES permit.