Subject : Addendum to Third Set of Comments on "Port of Seattle File Number 96-4-02325", Wetlands Permit, Notice of Application for Water Quality Certification and For Certification of Consistency with the Coastal Zone Management Program

Reports I'd been expecting arrived just when I was about to mail my comments dated 15 April 1998 so I delayed to add this. These comments are also in addition to those supplied at the April 9, 1996 hearing and those mailed in January of 1998.

Based on reviewing the reports sent to me by the U.S. Geological Services (see references (a1) through (a6)) and those mentioned in my prior comments, a DETAILED HYDROLOGY STUDY is needed prior to issuing a Water Quality Certificate or a wetlands permit. No additional stockpiling of Third Runway fill should be allowed on airport property until the environmental risks are assessed. This study should involve oversight by the US Geological Survey hydrology staff due to its developmental nature and far reaching consequences.

Substantive Hydrology Studies Non-Existent
Substantive hydrology studies do not exist that would answer the question as to the risks of dumping over 80 billion pounds of fill on top of the existing aquifers and underground piping. Even the report whose title includes "Southwestern King County" contains very little information on wells in the impacted area. It was not a site specific study, nor was it intended to be. Data in numerous reports needs to be combined into one report that uses the same set of units. Then a test program needs to be developed and executed to fill in the most significant data gaps. The proposed NPDES pollution studies are inadequate.

The EIS focuses on till layers functioning as boundaries rather than conductivities within aquifers. Within aquifers things travel over five times faster than in till (see Table 2 in ref. (a4)). Within the lenses in till, contamination also travels much faster. Even the number of aquifers and drinking water wells impacted is underestimated in the EIS.

Contamination Risks Underestimated
The risks of water contamination are underestimated in the project's Environmental Impact Statement. Data from a variety of reports indicate that the aquifers under Sea-Tac are vital to the health of the Des Moines Drift Plain and the area's drinking water.

Investigations Report 92-4098 indicates there are probably more aquifers under the Sea-Tac Airport than the EIS addresses.

Investigations Report 92-4098 (ref. (a6)) indicates that, in addition to the known aquifers, undifferentiated material above the bedrock exists that could contain one or more aquifers. A different Report, No 28 (ref. (a4)) shows in Plate 2 that some cities such as Federal Way have drilled into that undefined region and established the water level. I believe Federal Way now draws drinking water from that depth but there was insufficient time to confirm a retired Water Commissioner's comments on that subject. This same unconfined area is also shown under Vashon Island.

Federal Way water is at risk too but not mentioned in the EIS

• Aquifer (Vashon Advance Outwash) under Sea-Tac Airport discharges to Federal Way Hylebos Creek (ref. (a4) Luzier, Fig 20, pgs 40-42)
• Federal Way wells tap into an aquifer which extends under the Sea-Tac airport.

Aquifers under the airport discharge to the west directly into Puget Sound and discharge to the east to the Duwamish Valley (alluvial fill) (ref. (a4) Luzier, Fig 20, pgs 40-42)

Angle Lake is connected to the aquifer (ref. (a3), (a4) or (a5)) - sorry can't remember which report, the problem with reading four reports in a weekend when camping without a computer)

These aquifers are too important to limit assessments to 10 years as the EIS did, particularly, when they are based on the assumption that till "restricts the movement of pollutants". Even the EIS Chapter IV Section 10 "low hydraulic conductivities ranging from .3 to 0.00003 feet/day", doesn't seem so small when you convert it to 110 feet per year.

Chemical Reactivity Unknown
The interactions of the high iron content, hydrogen sulfide and natural gas identified in the area during drilling need to be evaluated. See ref. (a4), Table 9 Records of Wells for T22N, R4E in Luzier

The ingredients of deicers is unknown (ref. ) so their pollution risks can not be assessed. If carcinogens really are an ingredient as an official in Maryland suggests (ref. (a11)) , what is the impact on the aquifers?

Contamination Rate Calculations Unconservative
The assumptions that some have made in technical discussions, in technical reports related to airport construction and the project's EIS regarding effectiveness of till to protect the aquifers are unconservative. To quote, a recent e-mail from Gary Turney, Hydrology Supervisory of the US Geological Survey, (ref. (a2)):

All of the aquifers and semi-confining units will be connected vertically to some degree. That degree is dependent upon the degree of transmissivity of the semi-confining units. One common misunderstanding is that semi-confining units, such as till or clays, are impermeable. Water can indeed flow through tills and clays, just much more slowly than through sands and gravels.

a) Till layers contain lenses making it more permeable b) Till can be fractured making it more permeable c)There may be very limited till in some areas - see Table 10, Drillers' Logs, in Ref. (a4)
d) Map (a) of Plate 3 in Investigations Report 92-4098 (ref. (a6)) indicates the area is in close proximity to an area where the Qva and Qal aquifers are "in direct hydraulic connection, and function as one aquifer". This was not a Sea-Tac site specific report and it is possible that more direct connections may exist between aquifers under Sea-Tac than assumed.
e) Map (b) of Plate 3 in Investigation Report 92-4098 (ref. (a6)) identifies the area "where aquifers are assumed to have high hydraulic-conductivity values' Looking at the map, it looks like someone said, "Where should we expand to most likely contaminate the future water supply for the area. Several wells were already destroyed due to airport expansion (Luzier pg. 97 ref. (a4)).
f) The AGI report mentions discrepancies between assessments (ref. (a7).
g) EIS does not comment on documented contamination of existing aquifers

As you have probably guessed by now, I really need more public comment time.

A. Brown

Additional References (Jan 8 1998 comments included extensive list) (a1) Electronic mail, A. Brown, Myrtle Jones, Hydrologist, April 16, 1998
(a2) Electronic Mail Gary Turney, Supervisory Hydrologist, April 16, 1998
(a3) Leisch, Brice A. , Price, Charles E. and Walters, Kenneth, L, Geology and Ground-Water Resources of Northwestern King County, Washington, Washington State Division of Water Resources Water Study Bulletin No. 20, 1963
(a4) Luzier J.E., Geology and Ground-Water Resources of Southwestern King County, Washington, State Dept. of Water Resources Water Supply Bulletin No. 28, 1969
(a5) Richardson, Donald, Bingham J.W. and Maddison R. J., Water Resources of King County, Washington, U.S. Geological Survey Water-Supply Paper, 1852
(a6) Woodard, D. G. Packard, F. A., Dion, N.P. and Sumioka, S.S. , Occurance and Quality of Ground Water in Southwestern King County, Washington, U. S. Geological Survey, Water- Resources Investigation Report 92-4098, 1995
(a7) AGI Project 16,116.001, Draft Groundwater Quality Impact Evaluation Proposed North Employee Parking Lot Seattle Tacoma International Airport, SeaTac Washington, AGI Technologies, 11 April 1997
(a8) AGI Project 16,116.001, Groundwater Quality Impact Evaluation Proposed North Employee Parking Lot Seattle Tacoma International Airport, SeaTac Washington, AGI Technologies, 13 June 1997
(a9) Request for Public Hearing and Comments on Port of Seattle File Number 96-4-02325", Notice of Application for Water Quality, From A. Brown, dated 8 January 1998
(a10) Wetlands/Water Hearing Comments submitted by A. Brown, April 9, 1998 (includes Sea-Tac 24 hour maximum rainfall data)
(a11) Wetlands/Water Hearing Cassette Tape, April/May 1997 Weekend Headliner: Safe Skies, Safe Water by Ross Simpson, NBC News Extra. Submitted by Debi Wagner at Hearing April 9, 1998

Handwritten annotation : Also enclosed per Corp of Engineer's request : Cutler & Stanfield comments on Air Conformity Determination. It contains the Univ of Florida fill calculations.

Also attached copy of Table 2 of reference (a6)