TagStormwater(385)

Letter dated February 22, 2001 from Pam Bissonnette, Director, King County Department of Natural Resources, to Ann Kenny, Senior Permit Specialist, Washington State Department of Ecology Northwest Regional Office, regarding King County’s technical review of the Port Of Seattle’s Comprehensive Stormwater Management Plan (SMP) for Master Plan Improvements at SeaTac International Airport. The letter references

Letter dated February 22, 2001 from Pam Bissonnette, Director of King County Department of Natural Resources, to Ann Kenny, Senior Permit Specialist at Washington State Department of Ecology (DOE) Northwest Regional Office, regarding King County’s technical review of the Port Of Seattle’s Comprehensive Stormwater Management Plan (SMP) for Master Plan Improvements at SeaTac International Airport.

In February 2001, Northwest Hydraulic Consultants submitted technical review comments to the U.S. Army Corps of Engineers and Washington State Department of Ecology on behalf of the Airport Communities Coalition, raising concerns about the stormwater management plan for the proposed third runway at Seattle-Tacoma International Airport. The letter identified multiple deficiencies, including dam safety issues, vault structures that violated King County depth requirements, inadequate methods for assessing standing open water durations, and insufficient erosion and sediment control planning. These issues, the consultants warned, could pose risks to both structural safety and safe airport operations if not addressed prior to project approval.

A February 2001 technical review letter from Northwest Hydraulic Consultants, submitted on behalf of the Airport Communities Coalition, raises concerns about the stormwater management plan for Seattle-Tacoma International Airport's proposed third runway expansion. The letter identifies deficiencies in hydrology and hydraulics analyses, inconsistencies in stormwater detention standards, and the lack of a clear independent review process for the complex project. Reviewers warn that without stricter oversight and well-defined engineering requirements, the development risks significant adverse impacts to local streams and wetlands, particularly Miller Creek and Des Moines Creek.

A February 2001 technical review letter from Northwest Hydraulic Consultants, submitted on behalf of the Airport Communities Coalition, raises serious concerns about the stormwater management plans for Seattle-Tacoma International Airport's proposed third runway expansion. The review identifies multiple technical deficiencies in the project's hydrology and drainage designs, warning that they could cause significant adverse impacts to local streams and wetlands, particularly Miller Creek and Des Moines Creek. The letter also criticizes the lack of clearly defined stormwater control standards, absence of independent design review processes, and failure to provide financial guarantees for implementing the stormwater management plan.

Handwritten notes from an Ecology informational meeting with Erik and Ann dated February 14, 2001 (AR 018355-018357). Topics include stormwater plan analysis from Kelly Whiting and John Drybeck (water quality staff), Vasen Farm farmed wetland ratios (1:1 in-basin acreage, 2:1 out-of-basin replacement), enforcement vs. restoration, prior converted designation, Corps of Engineers wetland determinations, 509 overpass,

Email dated February 8, 2001 from Ann Kenny (Ecology Senior Environmental Specialist) to Andrea Grad, Peter Eglick, and Kevin Stock responding to PDA requests regarding Chapter 173-175 WAC Dam Safety review of Port Of Seattle Third Runway stormwater facilities. Covers ISW Lagoon #3, 25.5 acre-foot pond (SDW1A), 37.91 acre-foot pond (SDW1B), MSE wall Dam Safety

Handwritten field notebook entries dated 1/28/01 documenting a site visit to Ace Airport View (DM1 – Monitoring Station) near Des Moines, referencing Des Moines Creek, SDS 1 outfall into SW associated wetlands, steep side terrain, oil boom present in unit 2, turbid water, black stones, water from outfall significantly turbid, Dr. Strand took samples at

Port of Seattle technical appendices (Volume 2) to the study examining effects of runway deicing on dissolved oxygen (DO) in receiving waters at Seattle-Tacoma International Airport, covering the 1999-2000 winter season. Includes QA/QC and field methods for Hydrolab instruments, Northwest Ponds DO profile data collection, continuous monitoring data assessment, tracer plots for each monitoring location,

This December 2000 email from Northwest Hydraulic Consultants summarizes technical concerns about Seattle-Tacoma International Airport's Industrial Wastewater System (IWS) and its effects on local waterways. The consultants warn that diverting large areas of stormwater runoff to the IWS is reducing natural water flows to Walker Creek and Des Moines Creek, and that lining the IWS storage lagoons may further diminish groundwater base flows to those streams. Additional concerns include undersized detention facilities, lack of continuous simulation modeling, and unresolved conflicts with FAA wildlife guidelines related to the proposed Third Lagoon expansion.