Woodward-ClydeEngineering & sciences applied to the earth s, its environment

February 28, 1995

Ms. Lisa MarinoU.S. Environmental Protection AgencyRegion III841 Chestnut StreetPhiladelphia, PA 19107

RE: Submission of Supplemental Phase I Cultural Resource Study(Geoarchaeological Evaluation) of the Fomer Koppers Company, Inc.Newport Site, Newport, Delaware

Dear Ms. Marino:

Woodward-Clyde is pleased to submit a copy of the report entitled GeoarchaeologicalEvaluation, Phase I Cultural Resource Survey for the Former Koppers Company, Inc. Site,Ne\vport, Delaware for your review. This report has been prepared by our subcontractor,MAAR Associates, Inc., as an element of the revised RI/FS work plan for the formerKoppers Company, Inc. Newport Site. This study was initiated in response to commentsreceived from the Delaware State Historic Preservation Office during a meeting at the EPARegion III office on November 16, 1994. The report provides refinements to the prehistoricarchaeological sensitivity model developed during the Phase IA archaeological backgroundstudy (Phase IA Cultural Resources Survey for the Former Koppers Company, Inc. Property,New Castle County, Delaware by Douglas C. Kellogg et al., MAAR Associates, Inc., 1995).As an element of the remedial investigation, the document has been prepared to providea basis for evaluating the presence of significant prehistoric resources in areas whereremedial actions may occur at the referenced Superfund Site.

If any additional information is required, or if you have any comments regarding the report,please contact the undersigned.

Sincerely,

Scott Laird Charles H. LeeDeckerProject Manager Cultural Resources Specialist

CHL:chlcc: F. Stocum (DESHPO)

J. Patarcity (Beazer East, Inc.)J. Karmazyn (Du Pont)J. Buczala (WCC-Plymouth Meeting)

Woodward-Clyde Federal Services • A subsidiary of Woodward-Clyde Group, Inc904 Wind River Lane, Suite 100 • Gaithersburg. Maryland 20878 A R 3 0 6 3 I U301-258-9780-Fax 301-869-8728 M V ^ W W W -r

EXECUTIVE SUMMARY

This report has been prepared to provide a basis for evaluating the presence of significantprehistoric resources in areas that may be effected by remedial actions at the former KoppersCompany, Inc. site in Newport, Delaware. It provides refinements to the prehistoricarchaeological sensitivity model developed in the Phase IA archaeological background study(Kellogg et al. 1995). The refinements are based on geological data gathered during the PhaseI Remedial Investigation by Woodward-Clyde Consultants. Interpretations are also based onfield observations of the geomorphology of the study area and aerial photographs. The refinedprehistoric site sensitivity model supersedes the earlier model developed in the Phase IAarchaeological background report (Kellogg et al. 1995).

This report also derived an archaeological site integrity model that addresses landscapedisturbance on the former Koppers Company, Inc. site. The refined site sensitivity model wascombined with the integrity model to derive a site potential model. The site potential modeladdresses the probability for actually finding intact archaeological sites in the study area.

Geoarchaeological consideration of soil boring, aerial photograph, and topographic dataallowed refined mapping of the three factors on which the original prehistoric archaeological sitesensitivity model was based. The "distance to water" factor was modified based on theidentification of former stream positions. Soil drainage characteristics were clarified somewhatfor the areas south of the wood storage area, but were only tentatively refined for the majorityof the former wood storage area. Topographic details were clarified based on fieldreconnaissance after inspection of detailed contour maps.

The soil boring data collected during the Phase I Remedial Investigation allowed anassessment of disturbance in the area of the former Koppers Company, Inc. wood storage area.PAOI 1 (former wood treating area) was almost completely disturbed, with only some smallareas retaining any possible landscape integrity. Soil borings clearly showed that thenortheastern portion of the property was heavily disturbed and that fill was introduced over themajority of the wood storage area. However, areas of remnant plow zones and soil horizonsare present across the eastern and southeastern portions of the wood storage area. The area ofthe former New Castle County Sewage Treatment Facility was also heavily disturbed. Bycombining the revised site sensitivity model with the landscape integrity model, a prehistoricarchaeological site potential model was derived. The potential model takes into account boththe probability of prehistoric landuse and the impacts of subsequent agricultural and industriallanduse on prehistoric site survival. Based on the site potential model, the Phase IB field surveyfor archaeological sites can be efficiently undertaken, avoiding areas of disturbance and lowsensitivity.

A total of 31 acres were evaluated as having high potential for prehistoric archaeologicalresources, and these tended to be located along the marsh and stream edges south and east ofthe former wood treating area. Areas of moderate potential totaled 45 acres in extent, primarilyin upland areas adjacent to the former wood treating area. Finally, areas of minimum andnegligible potential comprise almost all of the former wood treating area as well as open waterand marsh land.

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TABLE OF CONTENTS

EXECUTIVE SUMMARY i

TABLE OF CONTENTS ii

LIST OF ILLUSTRATIONS iii

INTRODUCTION 1

Prehistoric Archaeological Site Sensitivity 1Geological Background 3

METHODS 6

RESULTS AND INTERPRETATIONS 9

Distance to Water 9Soil Drainage 14Topography 18Refined Prehistoric Site Sensitivity Model 20

LANDSCAPE INTEGRITY OF THE FORMER KOPPERS COMPANY, INC. SITE 24

Prehistoric Archaeological Site Potential 27

SUMMARY AND CONCLUSIONS 30

REFERENCES CITED 31

APPENDICES 34

Appendix I: Summary Interpretations of Soil Borings 34Appendix II: A Refined Location for Former Koppers Company, Inc. 40

Office Building

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LIST OF ILLUSTRATIONS

FIGURES PAGE

1 The Former Koppers Company, Inc. Site 2

2 Regional Drainage Patterns of the Study Region 5

3 Geomorphological Interpretations 10

4 Construction Plans for Delaware Power and Light Company 12Transmission Line Across the Former Koppers Company, Inc. Site

5 Aerial Photographic Interpretations of Soil Drainage 16

6 Soil Boring Interpretations of Soil Drainage Characteristics 17

7 Areas of Remnant Upland Topography 19

8 Overlay Map of Prehistoric Site Sensitivity Factors 21

9 Revised Prehistoric Site Sensitivity Model 22

10 Profile and Plan View of the Central Portion of the Former 25Koppers Company, Inc. Site

11 Soil Boring Interpretations of Disturbance 26

12 Prehistoric Archaeological Site Potential Model 28

13 Refined Location for the Former Koppers Company, Inc. Office Building 41

TABLES

1 Soil Borings Reviewed and Monitored 6

2 Aerial Photographs Consulted 7

3 ^ Explanation of Scoring for Former Koppers Company, Inc.Site Sensitivity Map 23

4 Prehistoric Site Potential 27

111

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INTRODUCTION

This document provides refinements to the prehistoric archaeological sensitivity modeldeveloped for the former Koppers Company, Inc., Newport, Delaware site (Figure 1) in a PhaseIA background study (Kellogg et al. 1995). The refinements are based largely on geologicaldata gathered during the Phase I Remedial Investigation by Woodward-Clyde Consultants (WCC)(Woodward-Clyde 1994b). The major source of data is soil borings taken as part of Phase Iof the Remedial Investigation (RI). Interpretations are also based on field observations of thegeomorphology of the study area1 and aerial photographs.

This report also addresses the issue of archaeological site integrity (that is, the potentialfor undisturbed archaeological contexts and deposits) on the former Koppers Company, Inc. site.Both the potential impacts of natural geological processes and agricultural and industrial land useon the archaeological record were considered.

The refined site sensitivity model was combined with the integrity model to derive a sitepotential model. The site potential model addresses the probability for actually finding intactarchaeological sites in the study area based on the likelihood of prehistoric occupation and theprobability of site preservation into the present-day. Thus, the Phase IB field survey forarchaeological sites can then be efficiently undertaken, avoiding areas of disturbance and lowsensitivity.

Prehistoric Archaeological Site Sensitivity

In the Phase IA report (Kellogg et al. 1995:3-12 - 3-15), a sensitivity map for prehistoricarchaeological sites was prepared based on three factors:

• Distance to marsh edge• Soil drainage characteristics• Topography

Areas within 100 m (330 ft) of the marsh edge were considered Highly sensitive basedon previously developed predictive models for the Delaware coastal plain (see Custer andBachman 1986a:131-132; Kellogg 1993b:60-71). Areas more than 100 m (330 ft) from themarsh edge were considered Medium sensitivity. Areas greater than 200 m (150 ft) from themarsh edge were considered Low sensitivity. The better-drained Aldino-Keyport-Mattapex-Urban soil complex was considered sensitive, while the poorly-drained Othello-Fallsington-Urbansoils were considered low in sensitivity for prehistoric archaeological sites. Topographic highs,low knolls, or ridges were also considered sensitive areas. A scoring system was developed for

1 The study area is the former Koppers Company, Inc., Newport, Delaware site. The term'site" will be reserved for designating historic and prehistoric occupation localities.

1

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SEE ABOVE

SCALE

MAI PROJECT: D-41

FORMERKOPPERS COMPANY, INC. SITE,

NEWPORT, DELAWARE

FIGURE 1

THE FORMER KOPPERSCOMPANY, INC. SITE

g n * ft

assigning sensitivity values to subareas of the former Koppers Company, Inc. site (Kellogg etal. 1995: Table 2).

Herein, the mapping of the three factors discussed above is refined based on newinformation. In the Phase IA report (Kellogg et al. 1995), the "distance to marsh" factor wasconsidered as a proxy for "distance to water" (e.g., stream). The assumption was that the marshedge represented potential former stream boundaries. Preliminary field reconnaissance suggestedthat closer examination of the landscape and aerial photograph interpretation could be used tobetter establish former stream courses and meanders.

The soil borings conducted during the RI investigation were used as a source of soilsdata, as well as potential landscape (geomorphological data), and also as a means for evaluatinglandscape and soil disturbance. Aerial photograph interpretation, coupled with fieldreconnaissance, was also considered a means for refining soil mapping of the study area, as theSoil Conservation Service maps (Matthews and Lavoie 1970) generalized and grouped the soils.

Finally, closer examination of large-scale topographic maps and field examination oftopographic features was expected to allow refinement of the topographic factor of theprehistoric site sensitivity map.

Geological Background

The general geological context and background of the study area is given in the RevisedPhase I Remedial Investigation Work Plan (Woodward-Clyde 1994a), and in the Phase IAarchaeological report (Kellogg et al. 1995). The project area is situated in one of the mostcomplex geological settings of Delaware. The former Koppers Company, Inc. site is on thefeather edge of the Coastal Plain just south of the Piedmont fall line. The study area is also atthe confluence of two of the largest streams in northern Delaware. Both steams are tidal alongthe southern and western boundaries of the study area, and the head of tide in White Clay Creekis just to the west (unpublished data provided by Steven Abott, USGS, Dover). Thus, the studyarea lies at the boundary between two geologic and geomorphic provinces and in an area ofactive stream and marsh evolution driven by sea-level fluctuations. To further complicate thegeology, sea-level stood above its present level during the last interglacial period circa 120,000years ago (Cronin et al. 1981; Riggs and Belknap 1988:152). The sea level was approximatelysix meters (20 ft) higher, so that the Christina River and White Clay Creek basins would havebeen completely submerged from the Delaware River shore to well beyond the ChurchmansMarsh vicinity. Much of the study area would have been submerged and the surface of the landwas reworked as sea-level rose and fell. During the Late Pleistocene and early Holocene, thesea level stood as much as 30 feet below its present elevation.

Characteristics of the geological context of the former Koppers Company, Inc. site thatare important to archaeological assessment of settlement patterns and site preservation potentialare discussed in more detail herein. The major geological factor determining the present

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geomorphology is the orientation and variability of Pleistocene deposits of the ColumbiaFormation. The Columbia Formation influenced:

1) the courses of subsequent streams; and

2) variability in surface topography and soils.

The Columbia Formation consists of gravel bars and channel fills with intervening areasof finer-grained sediments oriented roughly northeast to southwest. The Columbia Formationwas deposited subaerially as alluvial fans by the ancestral Delaware River probably fromdischarge of glacial meltwater heavily laden with sediments eroded from areas to the north(Jordan 1964; Jordan and Talley 1976; Spoljaric 1967,1972,1982; Scott Andres and KelvinRamsey, Delaware Geological Survey, personal communication). Thus, local drainage iscontrolled by both the contact between the Piedmont and Coastal Plain at the fall line and alsoby the orientation of surficial deposits.

There are only thin, limited sediments of late Pleistocene and Holocene age overlying theColumbia Formation. The surface expression of the Columbia Formation is moderated by a thinmantle of wind-blown silt (loess) deposited over the entire, region (Carey et al. 1976; Foss etal. 1976; Rebertus et al. 1989; Simonson 1982), resulting in a mosaic of topographic and soilcontexts. Some Holocene alluvial fan deposits are known from the fall line zone in Delaware,but these are limited in extent and not mapped in detail (Spoljaric 1972:21-24; Scott Andresand Kelvin Ramsey, Delaware Geological Survey, personal communication). As discussedin the Phase IA report (Kellogg et al. 1995), prehistoric inhabitants of the region used andsettled most frequently on higher and drier landscape elements.

Stream patterns also influenced prehistoric settlement. Larger streams providedtransportation routes and access to riverine resources. During the Holocene, tidal influencesassociated with sea-level rise led to the development of biologically-productive marshes in theChristina River and White Clay Creek (Custer 1982). In addition, the lower reaches of thesetwo streams lie within broad, active meander belts (Figure 2) developed during the latePleistocene. Thus, relationships between any particular locality and the rivers have changedover time. The desirability of a place for occupation would be affected, as well as the potentialfor fluvial deposition that might bury or erode archaeological deposits.

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MA1 PROJECT: D-41

KOPPERS COMPANY. INC. SITE.

FIGURE 2

FORMER REGIONAL DRAINAGE PATTERNS

NEWPORT. DELAWARE

1 flR"3U6323

OF THE STUDY REGION

METHODS

A network of soil borings (Figure 1) was established across the former KoppersCompany, Inc. site to gather geological and hydrological data on which to base a ConceptualSite Model (CSM) and obtain soil samples for analytical testing (Woodward-Clyde 1994b). Forthe purposes of the archaeological modeling, a number of soil borings were monitored in thefield (Table 1; Figure 1). In addition, the field logs for many of the other soil borings werereviewed (Table 1). Transcripts based on the original field notes were reviewed for theremainder of the soil borings (Table 1). Details of the soil borings that were not observed werediscussed with the Woodward-Clyde field geologists who supervised and logged the borings.Sediment recovered in thirteen soil borings was observed. The direct field observations, alongwith discussions with the field geologists, provided a basis for interpreting the soil borings notobserved by the author.

TABLE 1: Soil Borings Reviewed and Monitored

Field Originals TranscriptsMonitored Reviewed Reviewed

216 104 203 102401 106 204 103402 107 205 112403 108 209 113603 109 210 116609 110 211 120610 111 212 122615 115 213 206616 117 214 207617 118 215 208618 124 303 217619 125 306 605620 126 601 606

127 602128 604201 607'202

Originals = Original field notes recorded in the field by Woodward-Clyde geologists.

Transcripts = Abbreviated summaries of field notes entered onto standardized forms.

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Soil borings (SB) numbered 100 through 200 were taken within the operational areas (i.e.the former wood treating and wood storage areas) of the former Koppers wood treatmentfacility. Soil borings numbered 300 through 600 were taken from surrounding areas. The forty-four soil borings from the operational areas provide a potential glimpse of the pre-industrialsetting of the portion of the former Koppers Company, Inc. site used as a wood treatmentfacility. Geological logs for thirty-eight (Table 1) borings in the operational areas werereviewed, and one soil boring was observed. Examples of interpretations are discussed below,and summary interpretations of the soil borings are included as Appendix I. Completedescriptions of the soil borings will be provided in the RI report (in preparation).

Aerial photographs (Table 2) were examined for evidence of soil moisture contrasts andevidence of abandoned stream channels and other geomorphological features. Maps andhistorical documentation were included when available to clarify and refine interpretations. Soiland geological interpretations were discussed with representatives of the Soil ConservationService and the Delaware Geological Survey, and other information was provided by the NewCastle County Department of Public Works, Delmarva Power and Light Company, and the U.S.Geological Survey (USGS).

TABLE 2: Aerial Photography Examined

Date Scale Comments

1937 1:20,000 Black and White; two exposures

1937/ Oblique Black and White; Four exposures show the1938 wood treatment facility from four angles

1948 1:24,000 Black and White; two exposures

1961 1:20,000 Black and White; two exposures

1962 1:20,000 Black and White; 1 exposure enlarged toapproximately 1:8000

1968* 1:200 Enlarged acetate copy of Blackand White exposure

1973 1:30,000 Black and White; two exposures

1932 1:2000 Color Infrared; one exposure enlarged toapproximately 1:8000

1983 1:32,500 Color Infrared; two exposures

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TABLE 2: Aerial Photography Examined continued

Date Scale Comments

1988 1:40,000 Color Infrared; two exposures

1989 1:660 Black and White; one exposure, enlarged.--———-——,.—.,.*———-——————————————————————————————»—••—••«—————*•—•^——————————————————..».»•.————-——————————••—^—_

A blue print copy of the relevant portion of this photograph was obtained from the New Castle County Planning Department.

Geomorphological interpretations are based on geological principles of sedimentation,erosion, and stream flow (e.g., Bowen 1985; Butzer 1971:157-239; Krumbein and SIoss 1963;Reineck and Singh 1980; Schumm 1972). In general, sediment size and sorting are directlyrelated to water velocity in fluvial systems. Fining upward stratigraphic sequences indicatedecreasing flow velocity, while coarsening upward sequences indicate increasing flow velocity.Steep slopes on the landscape and abrupt changes in sediment stratigraphy indicate erosion orchanges in flow regimes and/or depositional environments.

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RESULTS AND INTERPRETATIONS

Distance to Water

Aerial photographs were analyzed for evidence of abandoned meanders and formerchannels of Hershey Run (Red Clay Creek2), White Clay Creek, and the Christina River. Froma regional perspective, there is clear evidence of active stream channel migration. The base ofChurchmans Marsh was probably established through migration of either White Clay Creek orthe Christina River over the area either sometime in the Holocene, and/or during an earlier highsea-level stand (e.g., the last interglacial 120,000 years B.P.3 when sea level stood circa sixmeters above its present level). There is also an abandoned channel of the Christina River southof its present channel through Hog Swamp on the south side of Interstate 95. Downstream ofthe former Koppers Company, Inc. site, typical meander bends of a sluggish coastal plain streamwere present in the Christina River before Interstate 95 was constructed (Figure 2).

More subtle features are present along the southern and western margins of the formerKoppers Company, Inc. site (Figure 3). Aerial photograph interpretation identified severalpotential abandoned river channels on the former Koppers Company, Inc. site (Figure 3). Onepossible channel was observed in a brief field reconnaissance undertaken for the Phase IA study(Kellogg et al. 1995), as has been verified herein. Additional channels were also observed infield reconnaissance undertaken for this Addendum and later verified through aerial photographinspection. Channels were identified by surface expression and form. Channel margins wereidentified by abrupt changes in slope representing stream-cut banks. Also, possible buriedchannels were identified in some soil borings.

The most significant conclusion drawn from the analysis of former stream channels is thatthe Christina River has migrated south from a position skirting the southern end of "the Boot" -a peninsula of land that separates the West Central and East Central Drainage Areas (Figure1). The former channel edge is marked by small islands in the marsh of the East CentralDrainage Area. The funnel-shaped marsh occupying the north half of the East Central DrainageArea has probably not been occupied by former stream channels; thus, the distance to waterfactor is revised for the southeastern portion of the former Koppers Company, Inc. site. Theremay, however, be a meander scar at the east side of "the Boot" where a steep slope abuts themarsh.

The East Central Drainage Area marsh is fringed along the Christina River and WhiteClay Creek by levees that rise over two meters above the marsh. These may be artificial dikes

2 Hershey Run occupies an abandoned channel of Red Clay Creek. At some time in thepast, Red Clay Creek meandered around the north end of Bread and Cheese Island and downthe channel now occupied by Hershey Run.

3B.P. = before present.

flR306327

MAl PROJECT: D-41

FORMERKOPPERS COMPANY, INC. SITE,

NEWPORT, DELAWARE

FIGURE 3GEOMORPHOLOGICALINTERPRETATIONS

10 AR306328

that allowed the marsh to be exploited for pasture or hay. No direct evidence for this could belocated, although historical documentation may exist. Churchmans Marsh is known to have beendiked from the mid-1800s until the 1930s (Brooks 1957:4-5). It is likely that the levees alongthe East Central Drainage Area of the former Koppers Company, Inc. site are not natural, over-bank flood deposits.

The geological development of the West Central Drainage Area is more complex thanthe East Central Drainage Area, An abandoned channel of White Clay Creek extends southfrom the west end of "the Boot" towards the confluence of White Clay Creek with the ChristinaRiver. A present-day island is a remnant of the channel margin that shows on earlier maps andaerial photographs. The north end of the channel ends rather abruptly at "the Boot." In aneffort to ascertain if the channel turned directly west or was perhaps filled to provide a base fora powerline tower, construction plans were consulted (Frank Sobonya, Delmarva Power andLight Company, personal communication). The plans (excerpt shown in Figure 4) do not callfor fill or pilings as a foundation for the tower; therefore, it is concluded that a channel flowingfrom the west had been deflected to the south by the Pleistocene gravels that compose "theBoot." Soil boring SB609 at the south end of the Boot was placed in an unimproved road andclearing under the powerline. Gravel is exposed in the surface of the road, and the soil boringencountered coarse sand and gravel continuously to a depth of over 60 feet.

There is further evidence of former channels along the southern margin of the WestCentral Drainage Area in the form of a low natural levee parallel to the active natural levee ofthe river. Furthermore, there are a series of deep gullies occupied by either standing water ormarsh cut into the upland edge at the southwest corner of the West Central Drainage Area.Several soil borings were added to the sampling program after Terrain Conductivity surveys(Woodward-Clyde 1994) aimed at locating anomalies were conducted. Soil borings SB615,SB616, SB617, and SB620 were placed in and near linear depressions in the southwest area ofthe study area (Figures 1 and 3). Demolition debris in the form of treated lumber, railroad ties,corrugated metal, and twentieth century glass and other debris had been dumped in thedepressions. The soil borings demonstrated that the linear depressions are segments ofabandoned channels. One large channel can be traced northwest to Hershey Run. Segments ofthe channel have been delineated as wetlands on maps developed during the Phase I RI.

The channel curves to the southeast from the location of Potentially Disturbed Areas(PDA) D, E, G, and F. South of the powerline access road, the channel is filled with water.The powerline access road crosses the channel on gravel fill. An alternate route for thechannel's connection with White Clay Creek may lie to the west where the present natural leveeof White Clay Creek dams a small drainage that leads north into PDA F. The channel crossesPDA D, E, and F and passes to the east of PDA G and C. The northern half of the channel isalmost completely buried, but the mouth of the channel is clear as a gap in gravel depositsexposed in the bank of Hershey Run. The mouth of the channel is also marshy and drainsuplands to the south and east. The area of PDA G is higher ground clearly lying on the westof the channel. Soil borings taken in PDA D, E, F, and G confirm the presence of the channel.For example, SB615 in PDA D was placed in the center of the linear depression and did not

11

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-—- — ' -• '""""•v:•C

EAST CENTRAL 5DRAINAGE AREA <i

»*i

- —— . £4.0'— • ————————————

^<t•^ END OFm•£1.5.3'

, . . • Q.P.f-L.tt

WEST CENTRALDRAINAGE AREA

V - I 3 8 I 3

MAI PROJECT: D-41FORMER KOPPERS COMPANY. INC. SITE.NEWPORT. DELAWARE _______

FIGURE 4CONSTRUCTION PLANS FOR DP&L TRANSMISSIONLINE ACROSS THE FORMER KOPPERS SITE______I

AR306330X £*

encounter any Columbia Formation sediments overlying the Potomac Formation. The channelhad cut completely through the Columbia Formation. The channel is judged to predate humanoccupation of the region (circa 12,000 years B.P.) because the northern half has been deeplyburied. The "distance to water" factor was not modified to reflect the presence of this ancientchannel of Red Clay Creek4.

Another possible channel may be present underlying the west half of the study area,extending from the northern end of the West Central Drainage Area to Hershey Run. Organic-rich sediments were encountered at depth in SB601. This and other more deeply buried channelsto the east would be substantially older than prehistoric human occupation of the region. RedClay Creek (Hershey Run) has apparently migrated west during the late Pleistocene, perhapspushed by sea-level fluctuations that repeatedly brought tidal influence into White Clay Creekand the Christina River. The "Boot" is apparently a Columbia Formation gravel bar that maytrend to the northeast, forming the west margin of the East Central Drainage Area. Soil boringsin PAOI 4 may have penetrated channel fill associated with the gravel bar, and the two centraldrainage areas are probably based on an underlying braided channel system of which the gravelbar that forms the Boot is a component.

The West Central Drainage Area itself was probably shaped by meanders of the ancestralWhite Clay Creek. The margins of the marsh are concave arcs bordered by steep slopes orscarps in several places. Three meander scars may be present as indicated on Figure 3. Theages of these former channel positions cannot be determined without chronological control (e.g.,radiocarbon dating). The channels would have been smaller than the present tidal channel ofWhite Clay Creek, and therefore probably pre-date tidal influence here which reached to theconfluence of White Clay Creek and the Christina River sometime after 3000 years B.P. (basedon Belknap and Kraft 1977). Thus, the channels are judged to be recent enough to haveinfluenced prehistoric use and occupation of the study area. It was not necessary to revise the"distance to water" factor for the West Central Drainage because it was originally based on themarsh edge. The marsh edge was, and is, an adequate approximation of former streampositions.

Soil Boring SB619 was placed near the north end of the worker's housing area (PDA C)on the western edge of the study area adjacent to marsh fringing Hershey Run. The boringencountered a thin, A soil horizon over coarse sand and gravel deposits. A six-inch thick lensof well-sorted, white sand was encountered at 3.5 ft. Coarse sand and gravel continued below,and water was encountered at 4.5 ft. The upper portions of the sequence suggest alluvial over-bank deposition. The lower deposits are probably Pleistocene in age, but the upper sedimentscould be relatively recent. Hershey Run most likely passed directly east of this location at sometime in the Holocene and later meandered to the west. There is a possibility of Holocenealluvial deposition here, and also, to a lesser extent, to the north where Hershey Run is directlyadjacent to the upland end of the former Koppers Company, Inc. site and north past the "Fire

See Footnote Number 2.

13

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Pond," Soil Boring SB303, taken south of the Fire Pond, encountered a thin layer of fill overeight feet of silty sand with some layering. Thus, the only area of potential Holocene alluvialdeposition on the former Koppers Company, Inc. site is a narrow strip along the western edgeadjacent to Hershey Run and its fringing marsh. There is little evidence of recent alluvialdeposition along White Clay Creek itself (except the natural levees discussed previously).

In summary, evidence of former stream channels is present in the study area. Channelsare apparently younger to the east across the study area, and ancient channels are deeply buried.Marsh is slowly encroaching on the north end of the East Central Drainage Area, but thesouthern half of the marsh has accumulated as the Christina River migrated south in geologicallyrecent times. The West Central Drainage Area was probably sculpted by stream meandersbefore tidal influences reached this area in the late Holocene, An abandoned channel that canbe traced northwest across the west end of the study area most likely pre-dates human occupationof the region.

Verification and dating of the abandoned channels and meander scars tentatively identifiedthrough aerial photograph interpretation and field reconnaissance would have to be based ontransects of cores as specified in the RI Work Plan (Appendix to Woodward-Clyde 1994a).The marsh coring proposed as part of the original Phase IB plan was intended to establish thepotential for prehistoric archaeological sites buried below marsh peats. That potential isconsidered low here for two reasons:

1) The low-lying areas that are being drowned by encroaching marsh are based onpoorly-drained soils; and

2) Meander scars and former channels would have destroyed or precludedarchaeological deposits elsewhere in the marshes.

For the purposes of Phase IB archaeological reconnaissance and survey, it is notnecessary to ascertain the age of the former channels and meander scars identified here.However, landscape and environmental reconstructions may be necessary as part of mitigationefforts for archaeological sites considered eligible for nomination to the National Register ofHistoric Places. It is recommended that marsh coring to establish the environmental context ofprehistoric archaeological sites be delayed until Phase II archaeological investigations, if deemednecessary, are carried out.

Soil Drainage

The study area was classified by the U.S. Soil Conservation Service as Othello-Fallsington-Urban, poorly-drained, nearly level soils, contrasting with areas of Aldino-Keyport-Mattapex-Urban, moderately well-drained, level to nearly level soils (Matthews and Lavoie1970). The majority of the study area, including almost all of the operational areas, wasmapped as belonging to the Othello-Fallsington-Urban complex with no attempt to delineate themembers of the complex. Likewise, only one large irregular area surrounding the West Central

14

AR3U6332

Drainage Area was mapped as relatively well-drained. Preliminary inspection of aerialphotographs suggested that finer resolution could be obtained for the study area. The soilborings also provided a basis for soil classification. The goal of the soil mapping undertakenhere was to establish contrasts between areas of well-drained soils and areas of poorly-drainedsoils.

The earliest aerial photography available dates to 1937, when the wood treatment facilitywas already in place. At the time, the two farms present on the southern half of the formerKoppers Company, Inc. site were still in operation and virtually the entire area was cleared.Differences in soil moisture are discernable in the plowed areas south and west of the woodtreatment facility. Wetter soils appear darker, while drier soils appear lighter. This generalinterpretation was confirmed through consultation with the Soil Conservation Service (Mary AnnLevane, personal communication). The same differences are present on photographs taken in1948, 1962, 1968, and subsequent images. Consistent interpretations of the soils are mappedon Figure 5. In general, the original SCS interpretation of a poorly-drained Othello-Fallsington-Urban complex contrasted with an Aldino-Keyport-Mattapex-Urban complex is supported;however, better resolution is possible in distinguishing soil drainage. No attempt was made toassign soils observed to named units or associations. The results allow refining of theprehistoric site sensitivity model in that poorly-drained areas within the moderately-drainedAldino-Keyport-Mattapex-Urban complex can be down-graded in sensitivity. On the other hand,better-drained areas could be distinguished within the poorly-drained Othello-Fallsington-Urbancomplex. These areas are upgraded in terms of prehistoric site sensitivity.

Soil drainage in the area of the wood treatment facility and wood storage area is almostcompletely obscured on aerial photographs. However, consistent features are present on aerialphotographs that were taken after the facility was removed. False color infrared photographsclearly show dark areas (water absorbs infrared wavelengths) that suggest standing water.Standing water was observed in these areas during field reconnaissance, and the Woodward-Clyde preliminary wetlands map corroborates these observations.

The soil borings taken in the operational areas provide an independent means of assessingsoil drainage in the wood storage area. Poorly-drained soils and parent material were identifiedbased on the presence of gleyed horizons and iron-staining and concretions, indicating a highwater table. Clay sediments near the surface also suggested poorly-drained parent material andthe potential for impeded drainage. For example, SB209 and SB210 encountered organic-richsilts, gleyed sediments, and iron-staining characteristic of poor-drainage. Soil borings to thewest did not exhibit these characteristics. As shown on Figure 6, soil borings in the areassurrounding the operational areas encountered well-drained soils or sediments. Within theoperational areas, a large portion of the eastern half could be delineated as poorly-drained basedon the presence of clays near the surface and ground water staining of parent material and B soilhorizons. Two other poorly-drained areas were identified in the western half of the woodstorage area. A linear area in the northwestern quadrant of the wood treating area appears tobe associated with a surface drainage leading to the northeast. The other poorly-drained areaheld standing water when observed during field reconnaissance in early 1995.

15

AR3G6333

a I-U.;T 121111p ^ — _ H ——— B ^li MlilLKS 4Uu

SCALE

MAI PROJECT: D-tlFORMER

KOPPERS COMPANY, INC. SITE.NEWPORT, DELAWARE

I-IGUIIE 5AERIAL PHOTOGRAPHIC ~^"

INTERPRETATIONS OF SOILDRAINAGE CHARACTERISTICS

AR30633U

MM PROJECT: D-41FORMER

KOPPERS COMPANY, INC. SITE,SOIL BORING INTERPRETATIONS

OF SOIL DRAINAGECHARACTERISTICSNEWPORT, DELAWARE

AR306335

PAOI 4 comprises the "South Ponds" and immediately surrounding terrain (Figure 1).Soil borings in this area encountered relatively intact soil profiles. A clear plow zone overclayey subsoil was encountered in SB403. Soil boring SB401 was placed near a stream channeland encountered a silt loam soil sequence that grades into sand and gravel. Soil boring SB402encountered iron-stained and gleyed5 sediments, indicating a high water table. PAOI 4 isgenerally low-lying and poorly-drained. An artificial earthen dam runs east-west across thesouth end of the area. Soil Boring SB608 was placed south of the dam to the west of the naturaldrainage. Soil Boring SB407 was to the west of SB608 on the same ridge. A borrow pit ispresent in the ridge south of SB407, and marsh lies to the south beyond the ridge. The SouthPond Area is not considered a sensitive area for archaeological resources; however, the well-drained ridge to the south (see Figure 5) is sensitive.

The aerial photograph and soil boring interpretations generally concur. In comparisonwith the U.S. Soil Conservation Service mapping (Matthews and Lavoie 1970), the soil mosaicis more complex and a large portion of the area mapped as the poorly-drained Othello-Fallsington-Urban complex may be relatively well-drained. The soil drainage factor as appliedto the prehistoric archaeological sensitivity model was treated conservatively, in that if an areawas not clearly identified as poorly-drained, then it was assumed to be relatively well-drained.

Topography

Analysis of the topography of the study areas was refined through examination of detailedcontour maps (1 foot contours at a scale of 1 inch = 100 feet) and field reconnaissance (Figure7). The area of the former Koppers Company, Inc. wood storage area has definitely beenleveled. Very little topography remains. The original topography was probably a gradual slopefrom north to south, but the office building apparently stood on a slight knoll that was finallyeliminated when the former New Castle County Sewage Treatment Facility building wasconstructed (see discussion in Appendix II). Areas of remnant upland topography (Figure 7)were delineated by tracing the lowest contour that was not observed in the field as a drainageor wetland. Small surface drainages may have extended up into the area of the wood storagearea, but cannot be clearly traced on the topographic maps and were not observed in the field.

In the eastern half of the wood storage area, Soil borings SB209 and SB210 encounteredorganic-rich silts buried below fill. Woodward-Clyde has mapped wetlands in the vicinity ofthese borings. The stratigraphy suggests deposition in small, closed basins similar to the"bay/basin" features more common on the central and southern Delmarva Peninsula (Custer andBachman 1986b; Rasmussen 1958). To the south of SB209 and SB210, Potentially DisturbedArea K appears to be a large circular bay/basin depression. Soil boring SB618 was taken nearthe center of the depression but encountered a disturbed sequence in the upper 2.8 feet. Thesediments became finer with depth before gravel was encountered at 6 ft. Reconnaissance of

5 Gleyed soil horizons are formed under conditions of high water tables or standing waterand are recognized by reduced (grey and greenish gray) colors and clayey texture.

18

AR306336

MAI PROJECT: D-4!

FORMERKOPPERS COMPANY, INC. SITE,

NEWPORT, DELAWARESCAL£

FICUItE 7AREAS OF REMNANT UPLAND

TOPOGRAPHY

19 AR306337

the area found that debris, including a portion of an auto body, had been pushed into the centerof the depression, creating a central mound now covered with dense underbrush and small trees.It is unclear from aerial photographs if this is a natural depression. The closed depressions arenot considered archaeologically-sensitive because of their proximity to major streams. The"bay/basin" features further south on the Delmarva Peninsula are significant because they werepotential drinking water sources for prehistoric peoples in upland settings (Custer and Bachmau1986b).

Soils drainage and topography are related. Areas surrounding the operations areaidentified as poorly-drained are topographically low or follow small drainages in most cases.For example, a small drainage leading northwest from the southeast corner of the study area wasidentified on aerial photographs as poorly-drained. Likewise, the complex soil pattern north ofthe West Central Drainage Area is mirrored in the topography of the area. Many poorly-drainedareas have been delineated as wetlands by Woodward-Clyde. Segments of the abandoned streamchannel identified along the western study area have also been delineated as wetlands.

Refined Prehistoric Site Sensitivity Model

Prehistoric site sensitivity for the study area was determined using the same proceduresas in the Phase IA report (Kellogg et al. 1995), with only minor modifications. First, all threefactors (topography, distance to water and soil drainage) were overlain on a single map (Figure8). As discussed previously, the "distance to water" factor was modified only along the easternhalf of the study area. Topographic features of the wood storage area could not be added basedon the present study, except that the area of the former Koppers Company, Inc. Office Buildingand presently abandoned New Castle County Sewage Treatment Facility stood on somewhathigher ground than surrounding areas (see Appendix II).

Scoring of areas based on the three landscape factors followed the Phase IA report(Kellogg et al. 1995: Table 2). However, because of the conservative nature of the revisedsoils mapping, poorly-drained areas were given a disproportionate weight (Table 3). If an areawas mapped as poorly-drained, then it§ sensitivity for archaeological sites is considered low evenif it is "close to water." The revised map designating areas of High, Medium, and Lowprehistoric site sensitivity is Figure 9. Note that several areas were given equivocal designations(H/M and L/M). Two areas of High-Medium sensitivity were identified along the westernboundary of the study area adjacent to areas of High sensitivity. The equivocal areas score 3(Table 2), but are somewhat lower-lying than the adjacent High sensitivity areas which score4. Similarly, the Low-Medium areas score Medium, but are somewhat poorly-drained.

20

AR306338

ML runs

MAl PROJECT; D-41

FORMERKOPPERS COMPANY, INC. SITE,

.,„. . c . NEWPORT, DELAWARESCALE •

FIGURE 8

OVERLAY MAP OF PREHISTORICSITE SENSITIVITY FACTORS

21 flR3U6339

II MliTliHS 41)11

SCALE

MAI PROJECT; D-41FORMER

KOPPERS COMPANY, INC. SITE,NEWPORT, DELAWARE

FIGURE 9REVISED PREHISTORIC SITE

SENSITIVITY MODEL

22

TABLE 3: Explanation of Scoring for Former Koppers Company, Inc. Site Sensitivity Map

Distance > 200 m (Low) 100 < >200 m (Medium) < 100 m (High)Score 0 1 2

Soils Wet DryScore 0 1

Topography Low-lying Knoll/ridgeScore 0 1

Sensitivity Scoring:

High sensitivity: Score > 3 (3 or 4)Medium sensitivity: Score = 1 or 2Low sensitivity: Score = 0

Explanation:

Scores for any particular place were calculated based on overlay maps of distance zones, soil associations, and topography (Figure 8). The iitesensitivity map (Figure 9) is based on sums of scores for the three factors. Any locality of wet soils was scored 0 and assigned to the lowsensitivity category, however.

Relatively large areas of the operations areas were classified as High or Mediumsensitivity, whereas they scored Medium or Low in the Phase IA mapping (Kellogg et al. 1985:Figure 6). The reason for this is the conservative approach to soils mapping. In the absenceof definitive evidence of poor drainage, better drainage was assumed. Thus, scores wereincreased for many areas especially in the western half of PAOI 1 and 2, but also along theeastern margin of the study area. Areas of High sensitivity were reduced in areas close to theWest and East Central Drainages. On the west, the presence of poorly-drained soils led to thereductions; and along the east, the reductions are related to redefinition of the "distance towater" factor. The revised prehistoric site sensitivity map presented here is as detailed aspossible without additional field work.

23

AR3U63U

LANDSCAPE INTEGRITY OF THE FORMER KOPPERS COMPANY, INC. SITE

Field reconnaissance of the wood storage area showed that the area had been coveredwith limestone gravel as a base for the railroad tracks. There is some slight topography to thearea oriented east-west parallel to the lay of the tracks (Figure 10). Silty sediments are exposedin road cuts across the area. Piles of railroad ties are dispersed across the area, and severalareas are poorly-drained and have been delineated as wetlands by Woodward-Clyde.

Soil borings taken along the northern edge of the former Koppers Company, Inc. siteconfirm the disturbed nature of the access road right-of-way (see Appendix II also). Fill oversand and silt facies of the Columbia Formation were encountered in SB106, SB107, SB108,SB109, and SB128. A plow zone or truncated B soil horizons were not encountered in theseborings. Soil boring SB110, taken to the east of the entrance gate near the original terminus ofthe rail spur leading into the former Koppers Company, Inc. site, exhibited an intact plow zoneover a truncated B soil horizon.

Relatively intact plow zone/soil profiles were encountered in soil borings in the westernhalf of the wood storage area. For example, SB211 revealed 4 inches of black silt with roadgravel over a light brown silt which overlay a mottled orange-brown silt. Columbia Formationalluvial facies underlay the surficial silts. The light brown silt is interpreted as a remnant plowzone with a truncated B soil horizon below. Similarly, SB213 and SB214 also had evidence ofa fill layer over relatively intact silty plow zones over mottled B soil horizons. The remnantplow zones may have been partially truncated but were not totally removed. Plow zones andremnant soil horizons were encountered in almost every soil boring taken in the area surroundingthe operations areas. PAOI 4 was disturbed during construction of the "South Ponds."Likewise, the fire pond area was disturbed in constructing of the "Fire Pond," although theremay be some undisturbed areas directly adjacent to the marsh west of the Fire Pond.

Soil Boring 610 was placed at the base of the slope on the eastern side of the East CentralDrainage Area. The boring revealed a thin plow zone over a yellow brown silt that gave wayto sand at three feet. Sand and gravel continued until the Potomac Formation was encounteredat a depth of 15 feet. Field reconnaissance and inspection of aerial photographs suggest that thearea east of SB610 is relatively undisturbed. However, the NPDES discharge pipe crosses thearea, and a large storm water drain pipe is buried along the eastern boundary of the formerKoppers Company, Inc. site. At the southeast corner of the project area, an artificial causewayextends to the Christina River.

Interpretation of the soil borings were plotted on a map of the study area (Figure 11).In general, the areas southwest and south of the wood storage area are relatively intact.Virtually the entire upland areas of the study area were plowed, probably including areas nowdesignated as wetlands. Plowing likely moderated the original relief of the area so thattopographic highs were truncated somewhat and lower areas filled due to soil erosion. Althoughplowing disturbs the upper soil horizons, plowing seldom completely destroys archaeological

24

«R3063i*2

SCALE

MAI PROJECT: D-41

FORMERKOPPERS COMPANY, INC. SITE,

NEWPORT, DELAWARE

FIGURE 10PROFILE &. PLAN OF CENTRALPORTION OF FORMER KOPPERS

SITE

25 AR3063U3

u H'liT i -1|u

II MLiTLllS 4HU

SCALE

MAI PROJECT: D-41

FORMERKOPPERS COMPANY, INC. SITE,

NEWPORT, DELAWARE

FIGURE USOIL BORING INTER PR ETATIONS~"

OF DISTURBANCE

26 aR3063UU

sites. In Delaware, many sites have yielded significant intact deposits below the plow zone insubsurface features (e.g., the Delaware Park site, the Clyde Farm site).

Industrial landuse, especially construction of the wood storage area, had a much greaterimpact on the original landscape of the study area. The surface of a large portion of the easternportion of the operational areas was removed and probably spread over the remainder of the areato level it for placement of the wood storage area. Fill is ubiquitous in the operational areas,but is especially deep in the southeast area of the wood storage area where small, closed basinswere present. Thin fill covers the western two-thirds of the wood storage area. Thus, a gentlyrolling topography, generally sloping to the south, west, and southwest, was leveled to createthe wood storage area. The area of the former New Castle County Sewage Treatment Facilitywas leveled further. In addition, a discharge pipe was buried across the eastern portion of thestudy area, and the large storm drain is buried under a berm along the eastern property line.The area of the former wood treating area where the wood treatment plant building stood isdisturbed. For example, SB 120 met with refusal and had to be offset 29 feet to the south of itsplanned location. David Friedman, Woodward-Clyde geologist, reported evidence of buildingfoundations in the area. Furthermore, the Terrain Conductivity Survey (Woodward-Clyde1994c:2-5 - 2-6) indicated that underground storage tanks may be present in the vicinity of theformer treatment buildings.

Prehistoric Archaeological Site Potential

Phase IB field survey for archaeological sites entails excavation of shovel test pits intransects or grids across a study area. Typically, areas of the highest sensitivity are tested ata higher rate than areas of lower sensitivity. The same is true in the case of disturbance.Heavily-disturbed areas are tested at a reduced rate or excluded from testing. A prehistoricarchaeological site potential model on which to base Phase IB testing plans is presented inFigure 12. A matrix of Site Sensitivity values and Integrity measures (Table 4) was used toestablish the probability of intact prehistoric archaeological sites. Figure 12 combines thesensitivity map of Figure 9 with the integrity map of Figure 11.

TABLE 4: Prehistoric Site Potential

SiteSensitivity

Low

Medium

High

Known

»

Low

Negligible

Negligible

Moderate

Moderate

Integrity

High

Low

Moderate

High

High

Notes: Site potential is based on the combination of site sensitivity and the degree of landscape disturbance that has occurred.Low disturbance implies high integrity, and vice-versa.

27 AR3063U5

U ____ 1-1- liT ________ '*""

II Ml; TUIU 4Uu

SCALB

MAI PROJECT; D-41

FORMERKOPPERS COMPANY, INC. SITE,

NEWPORT, DELAWARE

riGUKii 12

PREHISTORIC ARCHAEOLOGICALSITE POTENTIAL MODEL

28 AR3063146

Areas of definite poorly-drained soils are considered very low potential, regardless ofdisturbance, and will not require archaeological testing. Likewise, heavily-disturbed areas willnot require testing. Intensive testing is reserved for areas of the Highest archaeologicalsensitivity where prehistoric occupation is a virtual certainty or already known (but not fullydocumented). Little of the area occupied by the former Koppers Company, Inc. processing plantand wood storage area was classified as Highly sensitive for prehistoric archaeology. Only alimited area along the western margin of the study area adjacent to Hershey Run is Highlysensitive. The Fire Pond was excavated in a Highly Sensitive area, but the disturbance reducesthe archaeological potential there. Areas of intermediate potential were minimally disturbed andLow to Medium in sensitivity. These areas will require moderate testing. The magnitude ofthese areas may be reduced after initial archaeological testing if soil drainage is found to bepoor. The Minimal potential of much of the wood storage area may likewise be reduced if itis found that disturbance has been more severe than suggested by the soil borings.

29

AR3063U7

SUMMARY AND CONCLUSIONS

Geoarchaeological consideration of soil boring, aerial photograph, and topographic datahas allowed refined mapping of the three factors on which the prehistoric archaeological sitesensitivity model developed in the Phase IA report (Kellogg et al. 1995) was based. The"distance to water" factor was modified based on the identification of former stream positions.Soil drainage characteristics were clarified somewhat for the areas south of the wood storagearea, but were only tentatively refined for the majority of the former wood storage area.Topographic details were clarified based on field reconnaissance after inspection of detailedcontour maps.

The soil boring data allowed an assessment of disturbance in the area of the formerKoppers Company, Inc. wood treating areas. The former wood treating area was almostcompletely disturbed, with only some small areas retaining any possible integrity. Soil boringsclearly showed that the northeastern portion of the property was heavily disturbed and that fillwas introduced over the majority of the wood storage area. However, areas of remnant plowzones and soil horizons are present across the eastern and southeastern portions of the woodstorage area. The area of the former New Castle County Sewage Treatment Facility was alsoheavily disturbed. By combining the revised site sensitivity model with the integrity model, aprehistoric archaeological site potential model was derived. The potential model takes intoaccount both the probability of prehistoric landuse and the impacts of subsequent agricultural andindustrial landuse on prehistoric site survival. Phase IB archaeological testing can be guided bythis refined model that supersedes the prehistoric site sensitivity model developed in the PhaseIA report (Kellogg et al. 1995).

30

AR3063U8

REFERENCES CITED

Belknap, D. F., and J. C. Kraft1977 Holocene relative sea-level changes and coastal stratigraphic units on the northwest flank

of the Baltimore Canyon trough geosyncline. Journal of Sedimentary Petrology47:610-629.

Bowen, D. O.1985 Quaternary Geology: A Stratigraphic Framework for Multidisciplinary Work.

(Revised edition). Pergamon Press, Oxford, U.K.

Brooks, S. T.1957 Churchman's Marsh Wildlife Refuge. Society of Natural History of Delaware,

Wilmington, DE.

Carey, J. B., R. L. Cunningham, and E. G. Williams1976 Loess identification in soils of southeastern Pennsylvania. Soil Science Society of

America Journal 40:745-750.

Cronin, T. M., B. J. Szabo, T. A. Ager, J. E. Hazel, and J. P. Owens1981 Quaternary climates and sea-levels of the U.S. Atlantic coastal plain. Science 211:233-

240.

Custer, J. F.1982 The prehistoric archaeology of the Churchman's Marsh Vicinity: An introductory

analysis. Bulletin of the Archaeological Society of Delaware 13:1-41.

Custer, J. F., and D. C. Bachman1986a An Archaeological Planning Survey of Selected Portions of the Proposed Route 13

Corridor, New Castle County, Delaware. Delaware Department of TransportationArchaeology Series No. 44, Dover.

1986b Prehistoric use of Bay/Basin features of the Delmarva Peninsula. SoutheasternArchaeology 5(1): 1-10.

Fletcher, C. H., Ill1988 Holocene sea level history and neotectonics of the United States mid-Atlantic region:

Applications and corrections. Journal of Geology 96:323-337.

Fletcher, C. H., Ill, and J. F. Wehmiller1992 Quaternary Coasts of the United States: Marine and Lacustrine Systems. Society

for Sedimentary Geology Special Publication No. 48, Tulsa, OK.

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Foss, J. E., D. S. Fanning, F. P. Miller, and D. P. Wagner1978 Loess deposits of the eastern shore of Maryland. Soil Science Society of America

Journal 42:329-334.

Jordan, R. R.1964 Columbia (Pleistocene) Sediments of Delaware. Delaware Geological Survey Bulletin

No. 12, Newark, Delaware.

Jordan, R. R. and J. H. Talley1976 Guidebook: Columbia Deposits of Delaware. Open File Report No. 8, Delaware

Geological Survey, Newark.

Kellogg, D. C., B. C. Zebooker, D. Theime, and J. Schuldenrein1995 Phase IA Cultural Resources Survey for the Former Koppers Company, Inc. Property,

New Castle County, Delaware. Unpublished report submitted to Woodward-ClydeConsultants, Plymouth Meeting, PA, by MAAR Assoc., Inc., Newark, Delaware.

Krumbein, W. C., and L. L. Sloss1963 Stratigraphy and Sedimentation. (Second edition). W. H. Freeman, San Francisco.

Matthews, E. D., and O. L. Lavoie1970 Soil Survey of New Castle County, Delaware. United States Department of

Agriculture, Soil Conservation Service, Washington, D.C.

Rasmussen, W. C.1958 Geology and hydrology of the "bays" and basins of Delaware. Unpublished Ph.D

dissertation, Bryn Mawr College, Bryn Mawr, PA.

Rebertus, R. A., J. A. Doolittle, and R. L. Hall1989 Landform and stratigraphic influences on variability of loess thickness in northern

Delaware. Soil Science Society of America Journal 53:843-847.

Reineck, H. E., I. B. Singh1980 Depositional Sedimentary Environments. (Second edition). Springer-Verlag, New

York.

Riggs, S. R., and D. F. Belknap1988 Upper Cenozoic processes and environments of continental margin sedimentation: eastern

United States. In The Atlantic Continental Margin: U.S., edited by R. E. Sheridan,and J. A. Grow, pp. 131-1,76. DNAG Volume 1-2, Geological Society of America,Boulder.

32

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Schumm, S. A. (Editor)1972 River Morphology. Benchmark Papers in Geology Series. Dowden, Hutchinson and

Ross, Stroudsburg, PA.

Simonson, R. W.1982 Loess in soils of Delaware, Maryland, and northeastern Virginia. Soil Science

133(3): 167-178.

Spoljaric, N.1967 Pleistocene Channels of New Castle County, Delaware. Report of Investigations No.

10, Delaware Geological Survey, Newark.

1972 Geology of the Fall Zone in Delaware. Report Investigations No. 19, DelawareGeological Survey, Newark.

1982 Unconformities in the Fluvial Columbia Sediments Revealed by Thin Pebble Beds.Report of Investigations No. 35, Delaware Geological Survey, Newark.

Woodward-Clyde1994a Revised Work Plan: Remedial Investigation/Feasibility Study Former Koppers Company,

Inc. Newport Site. Unpublished report submitted to the U.S. Environmental ProtectionAgency, Beazer East, Inc., and Du Pont Chemicals.

19945 Field Sampling Plan Remedial Investigation/Feasibility Study Former Koppers Company,Inc. Newport Site. Unpublished report submitted to the U.S. Environmental ProtectionAgency, Beazer East, Inc., and Du Pont Chemicals.

1994c Terrain Conductivity Survey: Former Koppers Company, Inc. Newport Site, Newport,Delaware. Unpublished report submitted to the U.S. Environmental Protection Agency,Beazer East, Inc., and Du Pont Chemicals.

33

AR30635

APPENDIX I

SUMMARY INTERPRETATIONS OF SOIL BORINGS

SB1022' of fill over organic rich dark sand over buried plowzone and truncated B at 4 ft depth;

poorly drained subsoil.

SB103Intact plowzone; poorly drained subsoil.

SB 1042': silty fine sand; sandy gravel.2-4': refusal or brick with concrete.Attempted five offsets with refusal or brick/concrete/or metal in each one between 3.2

and 4 ft.

SB1060 - 2': B horizon with some gleying; silty clay.3.8': rootlets dark brown/gray silt.4 - 6': orange/brown with orange and olive mottling.

SB107Disturbed; 3.5 ft fill over truncated plowzone.

SB108Disturbed; no preserved soils.

SB1090 - 2.4': fill over plowzone.,2.4': B horizon.

SB110Intact soil 0-9" (plowzone).9" -2': B horizon.

SB111Fill; disturbed; brick fragments - probably in plowzone.2-4': subsoil is clayey - sand silt.

SB1120 - 4' of fill; disturbed.Truncates B soil; poorly drained.

34

AR3Q6352

SB1130-3': fill; disturbed over truncated B horizon; poorly drained.

SB115Truncated B soil; clayey at >4 ft.

SB116Fill; disturbed to 3'; no B soil.Somewhat poorly drained.

SB117Fill? to 3'.Organic layer at 5.6 - 6.2', over poorly drained subsoil.

SB118Thin fill over intact plowzone.Black silty fine sand; same as in SB4 area.

SB120Offset 29' south.Intact fluvial sediments (Columbia).

SB1223' of fill over intact plowzone.

SB1243' of fill compact, black organic silt 3 - 3.4'; looks like preserved A horizon underplowzone fill; poorly drained.

SB1252' of fill over plowzone.

SB126Truncated B soil horizon.

SB127Thin fill over relatively intact plowzone.

SB1280 -2': fill to 20", root fragments 20-24".2-4': becomes orange/brown then layered sand, silt, gravel to 31 ft.

35

AR306353

\SB201

0 - 2': 8" fill; 8"-2' tan silty plowzone.2-4': grayish brown with some decayed root fragments.4-6': gray to orange silt and clay.

SB2020-2': fill over truncated soil.2-4': light brown mottled orange silt - B horizon.

Columbia fluvial beds.

SB2030 - 2': 6" fill over truncated plowzone over B horizon. .Root fragments to 6'.

SB2042' of fill over relatively intact plowzone.

SB2056" of fill over truncated B horizon.

SB206Thin fill over truncated B soil; no clayey subsoil.

SB207Thin fill over truncated B soil; no clayey subsoil.

SB208Relatively intact plowzone over truncated B horizon; no clayey subsoil.

SB209Offset 100' NE5' of fill over organic silt layer, 1/2" black decayed organics over light gray clayey silt

to 7.5'.8 - 10': greenish gray with orange rust silt.Well-rounded gravel about 11.3 ft.

SB2100-4.5': fill4.5 - 5': dark gray silt over dark black decayed organic.6 - 8': dark grayish black clay.8.8;: light gray

SB2110 - 2': fill over truncated plowzone.2 - 4': B horizon; the Columbia fluvial facies

36

AR3U635U

SB212Thin fill over relatively intact plowzone.Clayey subsoil at 6'.

SB213Disturbed plowzone over indistinct B horizon.Relatively intact.

SB214Like SB213; relatively intact.

SB215Relatively intact silty plowzone over truncated B horizon.

SB2166" of fill over plowzone (small brick fragment at 1').2 - 4': B horizon then fluvial Columbia Formation facies.

SB217Thin fill over relatively intact plowzone.

SB3064.5': of fill over possible A/B horizon, alluvial1' of silt (mottled) over gravel.2-4': dry loose gravel.4 - 6': coarse gravel to 4.4' then brown, tan silt becoming organic brown.May be a preserved A horizon at 6.4 ft.

SB3038" of silty, fill.To 8': silty sand, layering light brown-orange.8 - 11.7': more clay.At 11.7': black; swampy-odor; silty fine sand.15': top of Potomac red clay.

SB401Thin A horizon silty loam to dark yellow/brown silt.0-2': with granular soil structure.2-4': grades into coarse sand and gravel.4 - 6': sharp contrast with sand and gravel layering until sand gray.

37

4 AR306355

SB4026": dark brown silt loam.12": yellow/brown, then silty clay with iron.8"; silty fine sand, iron stained.4-6', gleyed 1 cm bands.6-8', gray silty fine sand, grades light to darker.8 - 10', continues graded sequences silt - sand.

SB4030 - 2': silt, intact soil/plowzone.2 - 4': yellow/brown clay then sand and gravel, Columbia Formation.

SB601Plowzone/B horizonAlluvial Columbia FormationAt 7': black organic rich lenses in graded sequences, dipping.

SB602Fill over truncated plowzone over B horizon over sand and gravel Columbia Formation.

SB603Truncated A/B, silty fine sand, silty alluvium to 5.5' (with detrital organics); then clayey

and sandy beds alternate.Coarse sand and gravel at 10'.

SB6040-8": plowzone over silty remnant B horizon.8" - 4': B horizon coarsening sediments with depth.8': gravel

SB605Relatively intact; silty, some clay >5 ft.

SB606Relatively intact; silty.

SB607Disturbed plowzone over B horizon at 2.2'.Whitish brick fragment at 7.3'?24-30': sandyPotomac at 33'

38

AR306356

SB609No A horizon (in road).8" yellow/brown silty fine sand.Coarse sand and gravel at 3.8'.Continued gravel to ca. 60'.

SB610Truncated in clearing - thin plowzone over yellow/brown silt.Coarse sand at 3'.Sand and gravel to Potomac at 15'.

SB615PDA E in old channel.Silt to 5.4' fines downward.5.4' - gray/brown silt, some sand lenses.Columbia Formation missing, cut by channel.

SB616In road in PDA E.6.5' of fill.Layer of silt loam with slightly blocky structure - abandoned channel fill.7.5 - 8.5': Columbia Formation

SB617In PDA F.1' dark black silt over 1' yellow/brown silt.Continued silty sand to ca. 5 ft band of silty clay then gravel and cobbles at 5.7'.

SB618PDA K - in low area, disturbed.0 - 2': silty.2 - 2.8': as above then 0.5' yellow silt then coarse sand - fining downward sequence(generally) to 6', then gravel.

SB619North end of PDA C (Worker's housing area).Thin (5") A horizon, then coarse sand/gravel to 5' including lens of almost pure sand 6"

thick.

SB620In PDA G5' alluvial channel fill over sand and gravel, Area G.

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AR306357

APPENDIX n<•

A REFINED LOCATION FOR FORMER KOPPERS COMPANY OFFICE BUILDING

The location of the building used as an office for the former Koppers Company, Inc.facility (CRS # N-381) was tentatively identified based on a 1953 insurance map and othersources of data by Woodward-Clyde (Woodward-Clyde 1993a: Figure 2). A refined locationcould not be determined in deed and other research undertaken by MAAR Associates, Inc.(Kellogg et al. 1995), but the building was found to pre-date the former Koppers Company, Inc.facility.

SB104 was placed directly north of the existing building that housed a temporary sewertreatment facility for New Castle County between 1974 and 1977 (Woodward-Clyde 1993a:2-l).A complete soil boring could not be obtained at the planned location, so a series of five offsetswas attempted before SB 104 was abandoned. Each of the six attempts met with refusal on brick,concrete, or metal within four feet of the present surface. The approximate location of the officebuilding of the former Koppers Company, Inc. facility (CRS # N-381) was thought to benorthwest of SB104, based on the 1953 insurance map (Woodward-Clyde 1993a: Figure 3).However, based on examination of the "As Built" construction plans for the temporary sewerfacility (New Castle County Department of Public Works) and examination of aerialphotographs dated 1968 (New Castle County Department of Public Works), the building canbe more precisely located. The 1968 aerial photograph shows the .office building still standingand also shows the Sears warehouse building to the north across the Conrail tracks. The sewerfacility construction plans show the Sears building and the present building on the formerKoppers Company, Inc. facility. Measurements from these two sources and photocopy scalematching place the former office building directly under the north edge of the sewer facilitybuilding near the planned location of SB104 (Figure 13).

The temporary sewer facility construction plans also show that the existing topographywas modified for the facility building and access road. "As Built" plans show existing contoursand proposed contours and cross-sections for the road. As much as two feet was removed tolevel the road bed in front Of the sewer facility building and in places along the road to the eastwithin a 100-foot-wide construction easement. The area of the building itself was levelled to24 feet elevation, requiring the elimination of a small knoll 2 ft high and filling up to one footin lower areas on the edges of the construction site (Figure 13).

SB 104 likely encountered demolition debris from the former Koppers Company, Inc.office building and fill from construction of the sewer facility. It is possible that the initialboring attempt may have intersected the cellar or the foundation of the former office building.Subsequent boring attempts probably encountered demolition debris used as fill to the north andwest. Based on the soil borings and "As built" construction plans for the temporary sewerfacility, it appears that the locus and vicinity of the former Koppers Company, Inc. officebuilding (CRS # N-318) has been severely impacted and the foundation for the house may havebeen completely obliterated.

40

AR3U6358

J^EARS

APPROXIMATE LOCATION OF CRS #N-381

MA1 PROJECT: D-41FORMER

KOPPERS COMPANY, INC. SITE,NEWPORT, DELAWARE

FIGURE 13REFINED LOCATION FOR THEFORMER KOPPERS COMPANY, INC.

OFFICE BUILDING

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