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HomeMy WebLinkAboutRenton Commons Archeological Interim Progress Memo 650 South Orcas St., Suite 201 Seattle, Washington 98108 206-397-1487 www.willamettecra.com INTERIM MEMORANDUM Preliminary Archaeological Assessment for the Proposed Renton Commons Project Renton Washington Stephenie Kramer, M.S. May 20, 2016 Introduction The Low Income Housing Institute (LIHI) proposes construction of the Renton Commons, a multi-family housing development at 215 S. Whitworth Avenue in downtown Renton, Washington. LIHI contracted with Willamette Cultural Resources Associates Ltd. (WillametteCRA), to conduct an archaeological assessment of the proposed project area. WillametteCRA has commenced working on the survey project; this brief memorandum summarizes current field information and progress, provides information regarding the results of archaeological background research and field survey and preliminary conclusions based on those findings, and supports the project through the City of Renton’s application intake process. A full report that describes the natural and cultural setting of the project and full discussion of methods, results, conclusions, and recommendations will be forthcoming. The project site is on approximately 1/3 acre currently occupied by a single family dwelling at 215 Whitworth Avenue S., in the City of Renton, King County, Washington (Figure 1). It is a single parcel between 2nd and 3rd Streets in downtown Renton (Figure 2), T23N R05E, Section 18. The eastern half of the project parcel is occupied by a single family home (parcel 7841800090), constructed in 1930 according to the King County Assessor’s Office. The western half is a residential lawn and ornamental shrubs. The project as proposed would consist of demolition of the existing structure and construction of a six-story building that includes multiple residential units, common areas, classrooms, parking, and utility line upgrades. Design specifications may include a foundation that will be a structural slab 2 Figure 1. Project location map. 3 Figure 2. Project map with shovel probe locations. 4 supported by grade beams on pilings. A replacement storm main line (130 lineal feet), a water main line (500 lineal feet) and a sewer main line (150 lineal feet) will be constructed to connect to the new building. Archaeological Field Investigations Pedestrian survey within the project area for the proposed Renton Commons project was conducted on May 17, 2016 by Stephenie Kramer, M.S. and Malika Hays, B.A. Archaeological fieldwork consisted of pedestrian survey and the excavation of shovel probes throughout the parcel. Because the proposed project elements would extend throughout most of the parcel, meandering pedestrian transects were walked throughout the parcel. Shovel probes were excavated at an approximately 15-meter interval, modified somewhat depending upon obstructions by utility lines, vegetation and structures. The seven shovel probes measured 35-40 centimeters (cm) in diameter and varied in depth between 20 and 100 cm (Figure 2). The depth of most of the shovel probes was extended with the use of a 10 cm (4”) bucket auger to depths between 140 and 280 cm below surface. All sediment was screened through ¼-inch hardware cloth and sediment descriptions documented on field forms. All probes were backfilled upon completion, and locations recorded on an aerial photo map. Typical soil profiles in shovel probes 1-4 consisted of an approximately 30 cm thick sod and root mat, followed by approximately 80 cm of a light olive grey brown silty sand with no gravels. A light grey slightly saturated sandy clay, mottled with orange, approximately 100–145 cm below surface (cmbs) overlay a reddish brown coarse sand with some pockets of gray clay to 170 cmbs. A mottled sandy clay with iron oxide staining was noted between 170 cmbs and 190 cmbs. A wet, medium gray clay with some orange mottling was present between 190 cmbs and 210 cmbs. Between 210 cmbs and 240 cmbs a gray brown and orange iron oxide mottled fine clay is present, over a light yellowish brown medium coarse sand present to 275 cmbs. A light and dark brown mix of med coarse sand and dark brown silt was noted deeper, to the terminal depth of the probe at 280 cmbs. These sediments generally reflect a low energy alluvial deposit (Shong and Rinck 2011), which is expected, and reflective of the routine inundation of the area that likely occurred during flood events of the Black and Cedar Rivers before the channeling of the Cedar River in 1912, and the opening of the Lake Washington Ship Canal in 1916. When the elevation of Lake Washington was lowered, the Black River dried up. All of the probes yielded modern debris including occasional brown bottle and green bottle glass fragments and clear flat glass fragments and pieces of plastic in the first 50 cmbs. Shovel 5 probes 1, 2, 3 and 4 contained a fragment of terra cotta, and coal clinker and plaster. Shovel probe 4 also contained two small fragments of porcelain that were not temporally diagnostic. Shovel probes 5-7 exhibited a disturbed stratigraphy, or were impenetrable. Shovel probes 5 and 6 were placed on a flat, lower portion of the parcel. The far northwest corner of the property is noticeably more flat and level than the rest of the parcel and the surrounding parcels, and is two feet lower in elevation. For this reason, shovel probes 5 and 6 were placed there to attempt to determine if the topographic change was natural. The soil profile of shovel probe 5 consisted of a light brownish yellowish gray find sandy silt fill with 5-15% gravels and pebbles from 0-30 cmbs, distinctly more than in probes 1-4. The fill contained burnt waste material, burnt bits of plaster and two window glass fragments. From 30-78 cmbs the fill consisted of a compact yellowish brown fine sandy silt with fragments of burnt waste plaster and a fragment of white earthenware. At 78 cmbs, large fragments of concrete were found, and prevented further excavation. Shovel probe 6 was then excavated in the same area (~3 meters northwest) to corroborate these findings. Shovel probe 6 was disturbed to 100 cmbs. The first 60 cmbs consisted of a brown sandy silt with 5-15% pebbles. Immediately under the sod was a chunk of concrete, and a corroded nail was observed at 40 cmbs. Although the sediments from 60-100 cmbs consisted of an olive brown silty sand with orange mottling (similar to probes 1-4), corroded fragments of flat metal and occasional charcoal bits were present at these depths. This probe was augered from 110 cmbs and found an olive grey sandy silt with increasing moisture content to 160 cmbs. The sediments appear to be redeposited local sediments used as fill, likely reflecting a broader disturbed surface, although it is not yet clear what construction or demolition activity may have created this. Shovel probe 7 was excavated on the north side of the parcel between the house and the depression. This probe contained very compact light grey fill soils with 50% angular pebbles, and contained chunks of asphalt, concrete, a small brick fragment. The shovel probe was terminated at 20 cmbs because the density of the concrete chunks and soil compactness. The northwest corner of the lot featured an unusual depression, measuring 30 feet in diameter, and was approximately 7 feet deep in the center. The depression appeared circular, but was extensively overgrown with blackberry, Scotch broom, and various parts of the perimeter were covered in piles of lawn clippings. In addition to yard debris, the interior contained modern debris, including an upright vacuum, vehicle tires, plastic soda bottles, milled and treated lumber, an electronic Yahtzee game, and large pieces of concrete (~40cm) sat at the bottom. The northeast quadrant of the depression contained a remnant of stacked concrete, which may have been part of a foundation. On the southwest quadrant of the depression, a piece of concrete was located on the surface. This depression was likely created by the removal of a detached garage sometime between 2002-2004. 6 Preliminary Conclusions The Low Income Housing Institute (LIHI) proposes construction of the Renton Commons, a multi-family housing development on the current site of the 215 S. Whitworth Avenue in downtown Renton, Washington. LIHI contracted with Willamette Cultural Resources Associates Ltd. (WillametteCRA), to conduct an archaeological assessment of the proposed project area. No pre- contact archaeological resources were observed. Some fragmentary, non-diagnostic, possibly historic items were scattered on the parcel, including a fragment of stacked concrete in the area of the former garage. In the opinion of WillametteCRA, these items are not significant or represent an intact archaeological feature or deposit. However, based upon the nature of the landforms created by formerly meandering river channels, it may be prudent to have an archaeological monitor on site for deep excavations, including trenching for utilities in the northeast corner of the property, which was not accessible during this assessment. The monitoring would be to observe any pre-contact archaeological deposits which may be present under the current driveway, sidewalks, and Whitworth Avenue. Our recommendations will be finalized based upon further research and the research that BOLA Architecture + Planning will be conducting. The final survey report is in progress, and the historic property will be recorded and reported upon by BOLA Architecture + Planning.