Concrete Nurse Logs: Spawning Biodiversity from Ballard’s Century-Old Locks

Thesis (Master's)--University of Washington, 2016-08

Vasa Creek Channel Conditions and Slope Stability, Bellevue, Washington

The focus of this report is is the channel conditions at Vasa Creek, Bellevue, Washington, with regard to kokanee habitat and slope stability. This required a geomorphic and geologic assessment of the stream and riparian corridor along Vasa Creek. I focused my efforts in a 720m study-reach just south of I-90 in which City of Bellevue had no information. My assessment is divided into 3 categories: channel morphology, geology, and landslide hazards. I described the channel morphology by determining the gradient of the channel, longitudinal and cross-channel geometries, grain size distribution, embeddedness observations, type of channel reaches present, and the locations of significant in-channel woody-debris, landslides, scarps, landslide debris, and erosional features. This was done by conducting a longitudinal survey, 7 cross-channel surveys, pebble counts, and visual observations with the aid of a GPS device for mapping. I completed my geological assessment using both field observations and borehole data provided by GeoMapNW. Borehole data provided logs of the subsurface material at specific locations. In the field, I interpreted local geology using material in the channel as well as exposures in the adjacent slope. I completed the landslide hazard assessment using GIS methods supplemented by field observations. GIS methods included the use of aerial LiDAR to discern slope values and locations of features. Features of interest include the locations of scarps, landslides, landslide debris, and erosional features which were observed in the field. I classified 4 slope classes using ArcMap10 along with the locations of previously mapped landslides, scarps, and landslide debris. I describe the risk of slope failure according to the Washington Administration Code definition of critical areas (WAC 365-190-120 6a-i). My results are presented in the form of a map suite containing a channel morphology map, geology map, and landslide hazard map. The channel is a free-formed alluvial plane-bed reach with infrequent step-pools with riffles associated with landslide debris that chokes the channel. Overall I found that there is not the potential for kokanee habitat due flashy behavior (sudden high flow events), landslide inundation, and a lack of favorable conditions within the channel. The updated geologic map displays advance outwash deposits and alluvium present within the study-reach, as opposed to exposures of the Blakeley Formation along with other corrections from borehole data interpretations. The landslide hazard map shows that there are areas at high risk for slope failure along the channel that should be looked into further.

I-82 Prosser Landslide Investigation Benton City, WA

The scope of this technical report is to establish the mechanisms by which the eastbound lanes of Interstate 82 at mile post (MP) 91.9 near Benton City continue to deform. Within the Washington State Department of Transportation (WSDOT), the area is known as the Prosser Landslide and has been an ongoing concern since the 1980s. Results from previous technical investigations have been conflicted or inconclusive as to whether landslide movement persists beneath or through the shear key-buttress or that pavement distress is related to swelling of a clay-rich unit that underlies the slope and interstate. For this report, the following steps were taken. First, I conducted a desk review of archived reports, memos, data, and drill logs from the original construction of I-82 and previous geotechnical investigations commissioned by WSDOT. Findings of this desk review are reported in Part III. Second, WSDOT drillers drilled two new boreholes at the Prosser Landslide site above the buttress and instrumentation was installed within the boreholes. Borehole logs produced from the 2013 drilling can be found in Appendix A of this report. Material retrieved from the suspected failure zone during drilling was tested at the WSDOT Materials Lab by WSDOT personnel for its mechanical properties including Atterberg limits, grain-size analysis, and residual shear strength (Appendix B). Samples were also analyzed for mineral content using X -ray powder diffraction (XRD). These data and observations are reported in Part III and Appendix C. Finally, using drill logs produced by WSDOT from the latest drilling and from historic drilling campaigns, I constructed a 2-D geologic model of the landslide site. This model is the basis for slope stability analysis reported in Part IV and Appendix D. This study concludes that the deformation observed in the eastbound lanes of I-82 could be the result of continued landslide movement, despite previous remediation efforts.

Locating a strand of the Seattle Fault Zone in southeast Seattle, Washington through topographic analysis, borehole analysis and ground penetrating radar

Contributing to the evaluation of seismic hazards, a previously unmapped strand of the Seattle Fault Zone (SFZ), cutting across the southwest side of Lake Washington and southeast Seattle, is located and characterized on the basis of bathymetry, borehole logs, and ground penetrating radar (GPR). Previous geologic mapping and geophysical analysis of the Seattle area have generally mapped the locations of some strands of the SFZ, though a complete and accurate understanding of locations of all individual strands of the fault system is still incomplete. A bathymetric scarp-like feature and co-linear aeromagnetic anomaly lineament defined the extent of the study area. A 2-dimensional lithology cross-section was constructed using six boreholes, chosen from suitable boreholes in the study area. In addition, two GPR transects, oblique to the proposed fault trend, served to identify physical differences in subsurface materials. The proposed fault trace follows the previously mapped contact between the Oligocene Blakeley Formation and Quaternary deposits, and topographic changes in slope. GPR profiles in Seward Park and across the proposed fault location show the contact between the Blakeley Formation and unconsolidated glacial deposits, but it does not constrain an offset. However, north-dipping beds in the Blakely Formation are consistent with previous interpretations of P-wave seismic profiles on Mercer Island and Bellevue, Washington. The profiles show the mapped location of the aeromagnetic lineament in Lake Washington and the inferred location of the steeply-dipping, high-amplitude bedrock reflector, representing a fault strand. This north-dipping reflector is likely the same feature identified in my analysis. I characterize the strand as a splay fault, antithetic to the frontal fault of the SFZ. This new fault may pose a geologic hazard to the region.

Stratigraphic analysis of the southwestern quadrant of the Cedar Hills Regional Landfill: Incorporating recent borehole explorations and radiometric dating with previous investigations.

This report presents the results of stratigraphic analysis of the southwestern quadrant of the Cedar Hills Regional Landfill (CHRLF). My report was intended to incorporate the recent Area 8 borehole data into the pre-existing analyses. This analysis was conducted during the preparation of the Area 8 Hydrogeologic Report, but is my independent investigation and does not represent the opinion of UEC or their associates. The CHRLF, in Maple Valley, WA, south of Squak Mountain, is a municipal solid waste landfill that has been in operation since the 1960s. A network of borings, the product of previous investigations, exists for the study area. I utilized the compiled boring logs, previous investigations, and the recently acquired data to produce a series of interpretative cross-sections for the study area. I recognized 9 distinct stratigraphic units, including fill. My interpreted stratigraphic units are similar to those identified in previous investigations such as the Area 7 Hydrogeologic investigation (HDR Engineering and Associates, 2008). These units include pre-Olympia aged non-glacial alluvium, glacial alluvium, and glacial till. Additionally, younger, Vashon-aged deposits of glacial till, recessional outwash, recessional lacustrine, and ice-contact were observed. An isolated “till-like” deposit was observed below the Vashon till. This could possibly represent an older till as mapped by Sweet Edwards (1985) and Booth (1995). I cite the continuity of the lower contact of the Vashon till (Unit 5, Table 2) and the upper contact pre-Vashon non-glacial fluvial deposits (Unit 9, Table 2) as evidence that faults or other structural features do not offset the deposits in the study area. This conclusion supports the findings of the pre-existing body of work within the landfill property and the nearby Queen City Farms property.

Determining Spatial Distribution and Physical Properties of the Vashon Advance Outwash near Mountlake Terrace, Washington

This study is aimed at determining the spatial distribution, physical properties, and groundwater conditions of the Vashon advance outwash (Qva) in the Mountlake Terrace, WA area. The Qva is correlative with the Esperance Sand, as defined at its type section; however, local variations in the Qva are not well-characterized (Mullineaux, 1965). While the Qva is a dense glacial unit with low compressibility and high frictional shear strength (Gurtowski and Boirum, 1989), the strength of this unit can be reduced when it becomes saturated (Tubbs, 1974). This can lead to caving or flowing in excavations, and on a larger scale, can lead to slope failures and mass-wasting when intersected by steep slopes. By studying the Qva, we can better predict how it will behave under certain conditions, which will be beneficial to geologists, hydrogeologists, engineers, and environmental scientists during site assessments and early phases of project planning. In this study, I use data from 27 geotechnical borings from previous field investigations and C-Tech Corporation’s EnterVol software to create three-dimensional models of the subsurface geology in the study area. These models made it possible to visualize the spatial distribution of the Qva in relation to other geologic units. I also conducted a comparative study between data from the borings and generalized published data on the spatial distribution, relative density, soil classification, grain-size distribution, moisture content, groundwater conditions, and aquifer properties of the Qva. I found that the elevation of the top of the Qva ranges from 247 to 477 ft. I found that the Qva is thickest where the modern topography is high, and is thinnest where the topography is low. The thickness of the Qva ranges from absent to 242 ft. Along the northern, east-west trending transect, the Qva thins to the east as it rises above a ridge composed of Pre- Vashon glacial deposits. Along the southern, east-west trending transect, the Qva pinches out against a ridge composed of pre-Vashon interglacial deposits. Two plausible explanations for this ridge are paleotopography and active faulting associated with the Southern Whidbey Fault Zone. Further investigations should be done using geophysical methods and the modeling methods described in this study to determine the nature of this ridge. The relative density of the Qva in the study area ranges from loose to very dense, with the loose end of the spectrum probably relating to heave in saturated sands. I found subtle correlations between density and depth. Volumetric analysis of the soil groups listed in the boring logs indicate that the Qva in the study area is composed of approximately 9.5% gravel, 89.3% sand, and 1.2% silt and clay. The natural moisture content ranges from 3.0 to 35.4% in select samples from the Qva. The moisture content appears to increase with depth and fines content. The water table in the study area ranges in elevation from 231.9 to 458 ft, based on observations and measurements recorded in the boring logs. The results from rising-head and falling-head slug tests done at a single well in the study area indicate that the geometric mean of hydraulic conductivity is 15.93 ft/d (5.62 x 10-03 cm/s), the storativity is 3.28x10-03, and the estimated transmissivity is 738.58 ft2/d in the vicinity of this observation well. At this location, there was 1.73 ft of seasonal variation in groundwater elevation between August 2014 and March 2015.

An investigation of contaminant distribution in subsurface marine wood waste at Mill-A South Terminal, Port of Everett, Washington

This project investigates the correlation between contaminants and the wood waste present in marine sediments off the shore of the Port of Everett in the former Weyerhaeuser Mill-A pulp mill site. The investigation includes the results of two field studies, which tested contaminant levels in 22 boreholes as well as several surface samples. The contaminants include heavy metals and wood waste byproducts. These results, along with 14 other bore logs, provide the framework for a three-dimensional site model, interpolating the full extent of the depositional units and organic and inorganic chemicals found at Mill-A. The sediments of interest are divided into five depositional units defined by the percent wood content and type of wood: native material (<5% wood), intermediate (<30% wood), sawdust (<30% wood), woodchips (<30% wood), and poorly sorted sands with silt (SM-SP) (0% wood). The contaminants include arsenic, 2,4-dimethylphenol, and total organic carbon. Three-dimensional modeling software, RockWorks, interpolated the discrete borehole data of sediment and contaminants assuming horizontal continuity between sampling locations. The sediment distribution was calculated within concentration ranges for each contaminant of concern. The lowest detection limits, the screening levels, and the cleanup levels defined these ranges. Total organic carbon served as a proxy to estimate the quantity of wood waste in the sediment. As a known byproduct of wood decomposition, 2,4-dimethylphenol was expected to be more prevalent in the depositional units with more wood waste. Finally, arsenic was a proxy for other contaminants to determine if contaminants at Mill-A are dominant in sediments with high percentages of wood waste. The volumetric distribution established that high levels of total organic carbon are present in the sediment with higher percentages of wood waste. This correlation was stronger in the decomposing sawdust-rich sediment than the woodchip-rich sediment. The 2,4-dimethylphenol concentrations above cleanup standards were dominant in the sawdust-rich, intermediate and native sediments. Concentrations of 2,4-dimethylphenol below cleanup levels characterized the native sediment. The distribution of arsenic showed no statistically significant correlation to wood content in sediment. These results do not support the hypothesis of contaminant-rich wood waste, as many of the high concentrations of contaminants were not in the wood-rich sediments. This suggests that the contaminants are more distributed among all depositional units at Mill-A rather than focused within sediments with a high percent of wood waste. Understanding the distribution of potentially toxic compounds with wood waste is important for restoring the Puget Sound waterways to a more habitable environment. Future studies should include new data to validate these results and to limit the uncertainty of the extent of contaminants. Future studies may also find motive in looking for a correlation between contaminants and grain size based on previous studies linking these characteristics. These investigations will benefit the current cleanup effort as well as future cleanup efforts at similarly contaminated waterways.

Analysis of the Hydrogeological Conditions and the Effects of Development on the Hydraulic Head at Redmond Ridge East

Redmond Ridge East (RRE) is a large-scale master plan community in East King County, WA. In this report, I evaluate the spatial variability of the Quaternary Advance Outwash (Qva) at RRE and the time-series data for 16 water wells with the intent to better understand groundwater below the RRE area. I investigate changes between pre- and post-development conditions through the determination of temporal changes in annual water level, annual water level fluctuations, hydraulic head response to precipitation, and ambient drainage of the aquifer. I also perform a basic analysis of the annual aquifer recharge and a determination for the storage through the implementation of the water table fluctuation (WTF) method. Associated Earth Sciences (AESI) was tasked with monitoring the geological and environmental impacts during the development of RRE and collected the data I use in this report. AESI involvement in monitoring began in 1998 and extends to the present. Sixteen wells were identified in the RRE area with adequate temporal data to conduct the analysis. A comparison of the well logs and aquifer testing data allowed local variations in the Qva to be mapped. The WTF was used to determine a range of reasonable specific yield values for locations where the Qva was unconfined. Yearly average of the seasonal water level high and lows, and the fluctuations were quantified. Temporal relationships were established through linear regression. The average water level was found to be increasing in some locations, and the corresponding fluctuations were found to decrease. However, no clear change between pre- and post-development was observed. The response of hydraulic head to precipitation was investigated through an analysis of hydrographs for ten wells. Periods of consistent response and the corresponding precipitation during each period were delineated. A linear relationship between precipitation and water level change was determined. The threshold precipitation under which there is a positive response in the hydraulic head was established. No observable changes were apparent between pre- and post-development conditions. The ambient drainage for the Qva was calculated using recessional periods on the hydrograph. The transmissivity of Qva varies with thickness of the overlying lodgment till and thickness of the Qva, itself. Water level fluctuations observed in the Qva are consistent with regional observations. Localized areas in the Qva display the large 10 foot fluctuations and these anomalies are likely due to a combination of the local variability in the storativity as well as the concentration and channeling of water due to geographical variations in the Qva and the overlying topography. All trends seen in the RRE area remained relatively constant through time. There was no evidence showing an effect of development on the hydraulic head at RRE. This implies that the style and distribution of infiltration has not changed as a result of development, and that any measures in place are properly mitigating the effects of development on the RRE region.

Stem and Branch Diameter Response in Pruned Douglas-fir Plantations (Pseudotsuga menziesii var. menziesii): Implications for Volume and Clear Wood Production in the U.S. Pacific Northwest

Thesis (Master's)--University of Washington, 2016-06