TagStormwater(385)

A 1998 internal email exchange between Ken Ludwa and Kerry Ritland discusses edits to Section 4.3 of a stormwater management report related to Sea-Tac Airport. The section covers water quality facilities, explaining that new stormwater detention facilities would follow state Ecology guidelines using biofiltration and permanent water quality storage, while also complying with the Port's NPDES permit and Stormwater Pollution Prevention Plan (SWPPP). Ken Ludwa agreed to edit the section to reference Appendix F – Water Quality BMP Analysis once that appendix was further developed.

A July 1, 1998 internal email from Ken Ludwa to Paul Fendt outlines preliminary cost estimates for a StormFilter stormwater treatment system, based on a discussion with a VP of Stormwater Management. A 100 cfs system handling approximately 4,700 cartridges would cost roughly $2.3 million to design and build, while an 80 cfs system would cost approximately $1.8 million to build with $150,000 annually for cartridge replacement. Cartridge costs vary depending on total suspended solids (TSS) levels and rainfall, as cartridges are replaced on an as-needed basis.

Memorandum from Ken Ludwa (Parametrix, Inc.) to Paul Fendt dated July 1, 1998, project number 55-2912-01, describing results of a Reasonable Potential Analysis (RPA) for the STIA Third Runway area stormwater runoff. Analysis conducted at a working meeting with Lisa Zinner (Ecology), Lori Terry (Preston, Gates, and Ellis), Tom Hubbard (POS), John Rogers (CH2M Hill),

Draft Stormwater Quality Management Plan (Appendix F) prepared by Parametrix, Inc. for Port Of Seattle, July 1998, as part of the Preliminary Comprehensive Stormwater Management Plan for Sea-Tac Airport Master Plan Improvements. Covers existing drainage conditions including Storm Drain System (SDS) and Industrial Waste System (IWS), Miller Creek and Des Moines Creek receiving systems, existing

A July 1, 1998 memorandum from Parametrix, Inc. summarizes the results of a Reasonable Potential Analysis (RPA) conducted for the Seattle-Tacoma International Airport (STIA) Third Runway project, assessing stormwater runoff quality against water quality criteria for Miller Creek and Des Moines Creek. The analysis found that most pollutant concentrations after treatment with best management practices (BMPs) such as bioswales, sand filters, and wet ponds would meet criteria, with the exception of copper, which remained above acceptable levels. The memo also notes that during storms, pollutant concentrations already present in the receiving waters exceeded criteria and were higher than those predicted from Third Runway stormwater runoff.

A 1998 internal memo from Parametrix, Inc. summarizes the results of a Reasonable Potential Analysis (RPA) conducted for the Seattle-Tacoma International Airport (STIA) Third Runway project, assessing whether stormwater runoff from the new runway could exceed water quality criteria in Miller Creek and Des Moines Creek. The analysis found that most pollutant concentrations after treatment with best management practices (BMPs) such as bioswales, sand filters, and wet ponds would meet criteria, with the exception of copper, which remained above acceptable levels. The memo also notes that existing pollutant concentrations in the receiving waterways during storms already exceeded criteria, even before accounting for Third Runway runoff.

A June 30, 1998 email from John Rogers of CH2M to Thomas Hubbard and Ken Ludwa provides a website link (www.stormwatermgt.com) for a compost filter vendor, noting the company had recently changed its name. Rogers mentions that the vendor would be sending additional product information by overnight mail and water quality data by fax the following day. The correspondence relates to stormwater management and water filtration research being conducted in connection with Port of Seattle operations.

A June 1998 internal email from Ken Ludwa to Jim Kelley includes spreadsheet data comparing removal efficiency percentages for various pollutants—including solids, phosphorus, nitrogen, BOD, iron, lead, zinc, copper, bacteria, and total petroleum hydrocarbons—across multiple published studies from the 1980s and 1990s. The tables compile findings from sources such as Marselek et al. (1996), Metro (1992), and the UW Short Course, and conclude with recommended removal efficiency values for each pollutant category. This document appears to relate to Best Management Practices (BMPs) for stormwater treatment, likely in the context of environmental review for airport-related runoff management.

NPDES Waste Discharge Permit No. WA-002465-1 issued by Washington State Department of Ecology (Northwest Regional Office) to Port Of Seattle for Seattle-Tacoma International Airport, King County, WA. Permit covers industrial wastewater discharge to Puget Sound (Outfall 001), stormwater discharges to Des Moines Creek (Outfalls 002-005, 009, 010, 014, 015), Miller Creek (Outfalls 006-008, 011), City

NPDES Waste Discharge Permit No. WA-002465-1 issued by Washington State Department of Ecology (Ecology) to Port Of Seattle for Seattle-Tacoma International Airport, effective March 1, 1998, expiring June 30, 2002. Authorizes discharge of industrial wastewater to Puget Sound (Outfall 001) and stormwater to Des Moines Creek (Outfalls 002-005, 009, 010, 014, 015), Miller Creek (Outfalls