TagThird Runway(1084)

A September 2000 letter from Northwest Hydraulic Consultants raises concerns that the Seattle-Tacoma International Airport's Stormwater Management Plan fails to adequately assess or mitigate the third runway embankment's impact on stream base flows and seepage flows to nearby wetlands. The consultants argue that the Port of Seattle's own data contradicts its claims that the embankment fill would maintain groundwater recharge, and that independent re-analysis suggests summer groundwater reductions to Miller Creek could be roughly twice what the Port reported. The letter calls for more rigorous and consistent hydrologic modeling before construction commitments are made.

A September 2000 letter from Northwest Hydraulic Consultants, written on behalf of the Airport Communities Coalition, raises serious technical concerns about the Stormwater Management Plan for Seattle-Tacoma International Airport's proposed third runway. The letter highlights findings from King County reviewers showing that multiple stormwater facilities in the plan were unverified, potentially infeasible, or unlikely to meet required flow control performance standards. The consultants argue that the review timeline was insufficient and that the Port of Seattle had a history of failing to deliver promised stormwater mitigation measures.

In September 2000, Northwest Hydraulic Consultants submitted preliminary technical comments on behalf of the Airport Communities Coalition, raising serious concerns about the adequacy of the Stormwater Management Plan for Seattle-Tacoma International Airport's proposed third runway expansion. The letter highlights findings from King County's independent review, which identified numerous cases where proposed stormwater control facilities were unverified, infeasible, or unlikely to meet required flow control performance standards. The consultants warned that the compressed public review timeline was insufficient for thorough evaluation of the plan before Ecology's 401 Certification decision.

A September 2000 letter from environmental consulting firm Azous Environmental Sciences alerts Washington State Department of Ecology officials to an unidentified tributary of Miller Creek that was overlooked in the Port of Seattle's environmental planning documents for Sea-Tac Airport's proposed third runway. The tributary, listed in King County Sensitive Areas records and confirmed to have active water flow, feeds into a Class 2 salmon-bearing stream but was never assessed for potential impacts in the Port's Natural Resource Mitigation Plan. The letter argues this omission—despite four years of environmental analysis—leaves the creek unprotected from planned construction and future aviation operations in the area.

Hart Crowser report prepared for Port of Seattle, dated September 12, 2000 (J-4978-13), evaluating perched groundwater zone interception at Borrow Area 3 for the Sea-Tac Third Runway project. Analyzes shallow perched groundwater flow from northwest to southeast beneath Borrow Areas 3 and 4, its role in sustaining Wetland 29, and the impact of borrow area

Email from Peter Kmet to Kevin Fitzpatrick, Washington State Department of Ecology (Ecology), dated September 11, 2000, providing comments on proposed Clean Fill Criteria language for the Section 401 Water Quality Certification for the Sea-Tac Airport Third Runway project. Kmet comments on sections E6, E7, E7a, E7b, E7c regarding Port Of Seattle borrow sites, fill

Email chain dated September 11, 2000 among Kevin Fitzpatrick, Peter Kmet, Chung K. Yee, Joan Marchioro, and Tom Luster of Washington State Department of Ecology (Water Quality Program, NWRO) regarding clean fill criteria language for the 401 Water Quality Certification on the Sea-Tac Third Runway project. Document marked ‘Deliberative Document Currently Exempt From Public Disclosure.’

Email chain dated September 11, 2000 among Chung K. Yee, Kevin Fitzpatrick, Peter Kmet, Joan Marchioro (ATG), and Tom Luster regarding clean fill criteria language for the 401 Water Quality Certification on the Sea-Tac Third Runway. Key issues include arsenic limits (Pete Kmet argues 20 ppm is too high and should be set at Western

Email chain dated September 11, 2000 among Washington State Department of Ecology staff (Chung K. Yee, Kevin Fitzpatrick, Peter Kmet) and ATG’s Joan Marchioro regarding clean fill criteria language for the 401 Water Quality Certification on the Sea-Tac Third Runway. Peter Kmet raises concerns about arsenic limits (proposed 20 vs. background 7-8 in Western Washington),

Internal email exchange between Peter Kmet and Kevin Fitzpatrick (Supervisor, Industrial Permit Unit, Water Quality Program, NWRO) dated September 11, 2000, regarding Clean Fill Criteria language for the 401 Water Quality Certification on the Sea-Tac Third Runway project. Document marked ‘Deliberative Document Currently Exempt From Public Disclosure.’ Kmet comments on draft certification conditions E6 (borrow