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February 14, 2001 Washington State Department of Ecology Re: Port of Seattle, Ref. No. 1996-4-02325 Dear Mr. Freedman and Ms. Kenny: This letter comprises my comments regarding water and fisheries resources that could be affected by the proposed Third Runway Project and associated construction. My comments are submitted on behalf of the Airport Communities Coalition. My purpose is to assess if the Port of Seattle (Port) provides valid assurance that nearby streams, water quality and quantity, and fish will be maintained and protected. I base these comments on my 15 years experience as a fisheries biologist (see attached vita) and my familiarity with the subject area (sensu Hillman, T., J. Stevenson, and D. Snyder. 1999. Assessment of spawning and habitat in three Puget Sound streams, Washington. Report to the Airport Communities Coalition, Des Moines, WA). Although I have reviewed numerous reports generated as part of the proposed project, my comments here focus primarily on the following documents:
Below I identify sources of uncertainty associated with maintaining streamflows and water quality, mitigation measures and monitoring, and fish and their habitat. I conclude that the Port: (1) has not demonstrated that base flows and peak flows will be adequately mitigated, (2) provides no clear assurance that water quality will be protected, (3) has not clearly demonstrated that mitigation measures (e.g., BMPs) will protect the streams and their biota from potential impacts, (4) does not provide a valid monitoring program for assessing potential impacts to stream biota, and (5) has not addressed potential impacts to fish if mitigation measures fail. Water Quality and QuantityThe airport expansion project will fill wetlands and a portion of Miller Creek. According to the Supplement Biological Assessment (SBA), adding new impervious surfaces could change the hydrologic flow regime of Miller, Walker, and Des Moines creeks. The SBA states that if not properly mitigated, impacts would include increased peak-flow magnitude, duration, and frequency, and reduced base flows. The effects of high-flows would increase erosion, sedimentation, and habitat degradation in streams and increased sedimentation in the estuaries, while reduced base flows would decrease usable habitat for fish. However, the SBA suggests that mitigation actions will reduce peak flows and maintain base flows in the streams. The Port has not adequately evaluated and mitigated for effects of the proposed project on streamflows. For example, water rights are uncertain with respect to Miller and Des Moines creeks. Therefore, there is no certainty at this time that the Port will be able to maintain suitable base flows in these streams, even though the Low Streamflow Analysis report (LSA) states that the proposed project will reduce base flows. In addition, it appears that the well that the Port proposes to use to mitigate base flows in Des Moines Creek withdrawals some water from the upper unconfined aquifer. Inasmuch as the upper aquifer is connected with surface waters, it is not clear how this withdrawal will affect streamflows. As another point of uncertainty, I did not see evidence that the Port considered the effects of developing borrow sites in the upper Des Moines Creek basin on stream flows in Des Moines Creek. Development of these sites could increase surface runoff and peak flows and may reduce base flows if groundwater recharge is reduced. Finally, I found no information in the LSA describing the accuracy of the HSPF model low-flow simulations. If the models do not accurately simulate “real” stream conditions, we have no assurance that the mitigation actions will work. Importantly, if low-flow simulations are in error, then one can expect reduced usable habitat for fish in “losing stream reaches” (surface water goes subsurface). For example, flow data suggest that lower Des Moines Creek has a losing reach, which could be negatively affected if there are errors in the low-flow simulations. I am concerned that the Port has not adequately evaluated and mitigated for all potential water quality problems. For example, the Final Natural Resource Mitigation Plan (FNRMP) indicates that the Industrial Wastewater System is designed for a 25-year storm. There are unexplained impacts that will occur to the streams and their biota if the 25-year storm is exceeded. Although the concentrations of toxicants may be diluted, the toxicants from the airport would mix with the increased levels of toxicants from other sources (e.g., streets, yards, parking lots, etc.) and possibly overload the stream system. That is, even if the contribution of pollutants from the airport is relatively small, when combined with pollutants from other sources, the cumulative effects may still reduce fish production in the streams and estuaries. The Port has not demonstrated that water released into streams from detention facilities during low streamflow periods will meet water quality standards. There is no detailed discussions of metals, organics, dissolved oxygen, or temperatures of water in the facilities. Although the Port indicates that the water in the facilities will be cool, I found no data to support this assertion. Additionally, decomposition of organics in the facilities could create oxygen sags. Given that the water is discharged from the bottom of the facilities, entrainment of pollutants is likely. Untreated water discharged from these facilities into streams would degrade habitat conditions and negatively affect stream and possibly estuary biota. As a final note, I noticed that the Port will construct swales next to the new embankments (Sheets 27 and 28 in the Public Notice of Application for Permit, Second Revised Public Notice). These swales will capture runoff, sediments, and pollutants from the new embankments. This anticipates long-term shallow-soil disposal for pollutants. These swales are approximately 60 feet up-gradient from drainage channels. Over a period of time, pollutants will likely find their way to the drainage channels and ultimately to Miller Creek. If this happens, stream habitat and biota would be negatively affected. In summary, the uncertainty associated with water quality and quantity does not provide assurance that stream flows will be adequately maintained and protected. Therefore, as I explain later, there is reason to believe that stream and estuary habitat and their biota could be negatively affected. Mitigation Actions and MonitoringThe documents acknowledge that stream and estuary habitat degradation will occur if impacts from the proposed project are not mitigated. However, there remains uncertainty associated with the proposed mitigation actions. The FNRMP indicates that the Port will establish a 100 ft buffer (average) along about 6,500 linear ft of Miller Creek. I did not see information on the range of buffer widths, which may be more important than the mean. Figure 5.1-6 indicates that the stream is about 75 ft from the road and runway fill. In the Public Notice of Application for Permit, sheet 24 indicates that only a 50-ft riparian zone will buffer portions of Miller Creek. Fish-bearing streams require larger buffer widths. The Washington DNR requires buffers that vary from about 90 ft to 200 ft for fish-bearing streams. A buffer of 170-200 ft is required for Class II or I streams. These buffer widths are based on the best available data. The Port should be held to the same standards. Riparian zones trap pollutants and sediments, moderate stream temperatures, increase stream habitat diversity, and reduce bank erosion. Because the upper portion of Miller Creek will be next to the proposed project, a wider buffer is needed to protect the stream from sediments and pollutants associated with the construction and use of the proposed runway. The report notes that LWD will be selectively placed throughout the stream to improve instream habitat conditions. It is not clear what size of wood will be used and how it will be anchored. Depending on how LWD is placed, wood can end well above the wetted stream margin, useless to fish. High flows often dislodge LWD, carrying them downstream and potentially causing localized flooding. It is not clear how the Port intends to maintain LWD in the stream. The report on Essential Fish Habitat Consultation (EFHC) indicates that negative effects to stream habitat will be minor if the flow and habitat mitigation, and enhancement measures and BMPs, do what they are intended to do. However, the report provides no data or evidence (e.g., examples from other similar projects) that these measures will protect stream and estuary habitat. The authors presented no information where these measures (e.g., BMPs) have adequately protected stream habitat from such a large disturbance. One should seriously question the validity of the proposed BMPs, given that the efficacy of existing BMPs at the airport has not satisfactorily met water quality standards. That is, existing stormwater discharge from the airport has exceeded water quality standards. There is no assurance that the proposed BMPs will perform any better and will protect and maintain suitable stream conditions. With a project of this magnitude, if the measures fail, there will be significant impacts to the streams and their estuaries. The Port has outlined measures that they believe will maintain baseflows and prevent unusually high scouring flows. However, they presented no information on the minimum flow requirements for coho salmon, cutthroat trout, or other resident and anadromous species in the streams. The Port indicates that suitable flows or water depths (i.e., 0.25 ft) will be maintained to prevent stranding, but did not mention minimum flows required for rearing or spawning. If suitable minimum flows are not maintained, fish production in the streams could be reduced. That is, as flows decrease, usable rearing and spawning habitat decrease, resulting in reduced abundance, growth, or survival of fish. As I indicated earlier, this could be most significant in losing stream reaches. A related problem may occur in the relocated channel. As described in Sheet 16 in the Public Notice of Application for Permit, the “new” channel will be constructed over 2 feet of permeable gravels that extend horizontally about 40 feet. It is likely that during low-flow conditions the channel will go dry. Clearly, a dry channel provides no usable habitat for fish. The Port indicates that they will monitor stream conditions only during the first 10 years following construction. To terminate monitoring after 10 years may miss delayed effects. For example, toxicants or pollutants that percolate through the fill may enter the stream after the 10-year monitoring period. Groundwater quantity and quality should be monitored for more than 10 years. I found no information on how the Port intends to monitor quality of the groundwater within the embankment. It appears that pollutants or toxicants could find their way to the streams undetected. Finally, the Port provided no information that suggests they will monitor the quality of water released from the detention facilities. Fish PopulationsAn important omission in the documents is a detailed description of the status of fish populations in the streams and an adequate quantification of existing stream conditions. This information is basic to describing potential impacts to the streams and their biota. Presently there is no estimate of variability associated with baseline condition. The Port intends to describe baseline during one year only (i.e., year 0). This will not provide enough information to adequately assess potential impacts. In addition, invertebrates (BIBI) will be the only stream biota monitored during the proposed 10-year period. The Port acknowledges that the BIBI cannot be used unequivocally to assess the effects of mitigation actions and will not be linked to performance standards. Given that the BIBI is apparently the only biological parameter monitored, the Port cannot assess effects of the expansion and mitigation on biological components of the stream ecosystem. According to the EFHC, the project will have short-term effects on the habitat of coho salmon. It is not clear what is meant by “short-term.” Importantly, if the project affects the habitat of coho salmon, then it will certainly affect the habitat of cutthroat trout, pumpkinseed, and other species. In addition, the report does not attempt to translate the short-term impacts into lost production of coho salmon or other fishes in the streams. Currently, large numbers of female coho die before voiding most of their eggs. This condition suggests a potentially serious ecosystem health problem within the watersheds. It is possible that negative impacts from the proposed project could significantly affect the production of coho and other species within the streams. The EFHC indicates that the proposed project will not affect the EFH of chinook or pink salmon in the Sound. Although it may be true that the two species will not rear near the effluent, it does not demonstrate that possible prey items will not migrate from the effluent area to salmon rearing areas. That is, pollutants from the effluent could find their way to salmon through the food chain. The Port needs to provide information on the biology of salmon prey items in the Sound. Because there remains uncertainty associated with water quantity and quality and with the efficacy of mitigation actions and BMPs, there is reason to believe that the proposed project will affect the habitat and biota in the streams and perhaps estuary. As noted in the SBA, impacts would be in the form of stream erosion, sedimentation, and habitat degradation. This means that habitat diversity, spawning and rearing habitat, and food production could be reduced. Aquatic habitat is currently degraded within the streams. Additional insults to the streams will further reduce the already degraded habitat available to fish. A likely problem will be an increase in sediments to the streams. If BMPs work correctly, they should reduce sediment inputs, but will not likely prevent all inputs of sediments. Therefore, some input of sediments during construction and storm events is expected even if mitigation actions work properly. Increasing sedimentation can fill rearing pools and embed spawning habitat. Deposition of fine sediments on redds (nests) can kill incubating embryos and alevins. High flows can scour spawning habitat, transport wood and spawning gravels to the estuaries, and flush fish from the streams. These factors all lead to reduced survival, growth, and abundance. Poor water quality can also affect the survival, abundance, and growth of fish in the streams and estuaries. Pollutants from the airport can mix with urban pollution to reduce water quality conditions in the streams and estuaries. If toxics exceed threshold levels, fish will die. At lower concentrations, fish growth and behavior may be affected. Currently, female coho salmon die before voiding most of their eggs. If water quality is further degraded, one may see larger reductions in fish production. During storm events, plumes of polluted water could pass through the estuary, affecting the survival of organisms there. The NMFS has identified estuaries of Miller and Des Moines creeks as critical habitat for ESA-listed chinook salmon. The presence of polluted water near the mouths of the streams could reduce the available habitat of young chinook salmon that rear near the stream mouths. At this time the Port has not demonstrated that the proposed project will have no negative effect on the streams, aquatic habitat, and biota. With the lack of certainty associated with water quality and quantity, and mitigation measures and BMPs, I do not believe the Port has offered reasonable assurance necessary for certification or approval. Yours very truly, Tracy W. Hillman, Ph.D. Attachment: Vita |
