Shot Tower Archeological Contract
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MEMORANDUM
July 13, 2006
TO:
The Honorable Mayor and City Council Members
FROM:
Michael C. Van Milligen, City Manager
SUBJECT: Dubuque Shot Tower Archeological Investigation
Assistant Planner Dave Johnson recommends City Council approval of a contract in the
amount of $14,315.47 with Great Lakes Archeological Research Center to perform the
Shot Tower Archeological Survey.
I concur with the recommendation and respectfully request Mayor and City Council
approval.
(Y)J!{~J--
Mic~ael C. Van Milligen
MCVM/jh
Attachment
cc: Barry Lindahl, Corporation Counsel
Cindy Steinhauser, Assistant City Manager
Laura Carstens, Planning Services Manager
i5UB~E
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MEMORANDUM
July 12, 2006
FROM:
Michael C. Van Milligen, City Manager
David Johnson, Assistant Planner~.
TO:
RE:
Dubuque Shot Tower Archeological Investigation
On February 20, 2006, the City Council approved the issuance of a Request for
Proposals for the Shot Tower Archeological Survey which was estimated to cost
$30,000. On March 13, 2006, the Consultant Selection Committee met, reviewed the
proposals, and recommended selecting Great Lakes Archeological Research Center
(GLARC) to perform the archeological survey. The compensation for the work
performed by GLARC will be $14,315.47.
Please review and sign the enclosed contract and scope of work and return to Assistant
Planner David Johnson.
enclosures
A#'I'
t .;/
Laura Carstens
Planning Services Manager
City of Dubuque
City Hall
50 West 13th Street
Dubuque, Iowa 52001-4864
May 8, 2006
Dear Ms. Carstens,
Thank you for selecting Great Lakes Archaeological Research Center, Inc. to conduct archaeological investigations
for the Dubuque Shot Tower Project. We look forward to working with the City of Dubuque on this project. GLARC
will conduct the investigations as specified in the AI/achment 1: Scope of Work. If there are any questions or concerns.
please contact me at (4 I 4) 481-2093 extension 100 or at ienniferharve.Y@gLarc.com.
Sincerely,
Jennifer R. Harvey, President
Concur:
Name, Title
Date
Attachment 1: Scope of Work
1.0 PROJECT DESCRIPTION AND RESEARCH GOALS
1.1 Project Overview
The Dubuque Shot Tower Archeological Investigation will combine archaeological and
geomorphological research methodologies to resolve conflicting mid-19th and early 20th-century
accounts about the structural height of the Shot Tower and to evaluate the immediate area ofthe
Tower to determine its potential to yield additional archeological materials. In addition, data
generated by the study will be used to determine the best way to manage the site in regards to
existing and future threats to the property and to assist the Iowa Department of Natural Resources
determine the level of residual contaminant by"products resulting from lead shot production at the
Shot Tower property.
1.2 Research Goals
The two primary research goals of the Dubuque Shot Tower Archeological Investigations Project
are I) to identif'y how much of the originaIly exposed Tower column base is currently buried and
2) to determine the nature of the foundation supportslbase of the tower. In the course of
answering these questions, secondary ones that will be pursued are to measure the level of lead
contamination in soil sequences immediately adjoining the Shot Tower, and to record the
presence/absence of archaeological materials, for example, lead shot, related to the use of the
Shot Tower area. Data generated to explore these issues will be derived from two limited spatial
contexts: I) the area between the exterior walls of the Shot Tower foundation and an encircling
concrete foundation supporting a wrought iron fence, and 2) the area(I3' 2" by ]3' 2") within the
interior waIls of the Shot Tower foundation. The exterior area is capped with concrete except on
the river side, where a dirt surfaced area, which extends outside of the fenced area, measures less
than 10 feet wide by approximately 20 feet long. This exposed area will be the focus ofthe
subsurface investigations located exterior to the Shot Tower foundation.
2.0 PROJECT SPECIFIC TASKS
2.1 General Approach
In order to meet these goals, a stepped research design will be executed for the study. The stepped
approach consists of seven research activities that create a hierarchy of tasks, which lay a basis
for each ensuing task(s). Tasks will consist ofarchivaIl1iterature research, field mobilization,
geomorphological investigation, preliminary field analysis of data, archaeological excavations,
formatting field data for interpretation, and report preparation/finalization. This stepped structure
permits the study to be completed in an orderly and efficient manner; a task is not performed until
relevant prior research or activities had been completed. Of the seven research tasks, five primary
ones, which are discussed in greater detail in the folIowing sections, are archival/literature review,
geomorphological field investigations, archaeological excavations, laboratory analyses, and
report preparation.
2.2 ArchivaIlLiterature Review
A variety of archival materials and background literature will be reviewed for the Shot Tower
study. These materials will include geomorphological and paleo-environmental studies, historical
accounts describing the shot tower and its surrounding area, and archaeological and architectural
evaluations of the property. Review of geomorphological and paleo-environmental studies will be
very useful for cbaracterizing the sedimentological context of the area and providing a context for
interpreting sediments exposed during the geomorphological and archaeological field work.
Historical records related to the Shot Tower will be reviewed in light of the geomorphological
data derived from existing studies in order to determine if the two sources when viewed together
provide insights about discrepancies between 19th- and 20th-century accounts of the structure's
height. Air photos, newspaper stories, land survey records, local histories, and other historical
documents will be reviewed as deemed necessary, and when specific records, issues, or accounts,
for example, a news account of a specific flood event, can be identified from the data records.
2.3 Geomorphological Field Work
The geomorphological field investigation will consist of extracting four soil cores from the
exterior ofthe Shot Tower walls and one-to-three from sediments associated with the interior of
the structure. A truck mounted Geo-probe will be used to take four exterior core samples, which
will be extracted from each side of the Shot Tower. Due to the presence of a stone retaining wall
with iron fencing and 4-to-5 feet gated opening surrounding the structure, the mounted geo-probe
cannot be taken into the fenced area, and as a result, exterior cores will be taken immediately
outside ofthe fenced area. The advantages of the Geo-probe over other coring devices are that the
Geo-probe is minimally intrusive, having very little impact on archaeological or architectural
features, and can be used to penetrate stiff, resistant stratigraphic deposits. In addition, the core is
continuous, producing a readily interpretable soil sequence and may be subjected to various
chemical, environmental, and archaeological analyses. Recovery of four cores will permit tight
correlation of sedimentary deposits adjoining all sides of the Shot Tower, and this will allow
more detailed and controlled interpretation of the conditions that created the sequences and what
these mean in terms of the construction and height of the Tower.
On the interior of the Shot Tower, the sedimentary sequence and possible well area will be
investigated using a hand coring device or a power auger. One-to-three bores will be made, the
number depending upon the quality of the subsurface data generated by the initial soil bore. The
depth of the cores and the stratigraphic sequence of the post-1930s flood water deposits will be
interpreted with the 1934 Historic American Buildings Survey (HABS) drawing measurements in
order to determine the presence of the well opening and the accuracy of the historical drawings.
These results may then be correlated with the information derived from the exterior soil cores in
order to determine the depth of the Shot Towers foundation base and the significance of the
sediments adjoining the exterior walls in terms of how they have influenced the interpretation of
the Shot Tower's elevation.
2.4 Archaeological Field Work
Archaeological field investigations will be performed as needed and will be hased upon the
results of the geomorphological study. Specifically, archaeological excavations, which may
include hand dug 1.5 meter (m) by 0.5 Tn, or 2.0 m by 0.5 m test trench units, may be used to
investigate stratigraphic sequences, recover archaeological materials, or expose architectural
features that do no extend more than 4.5 feet below the ground surface. Excavation below the
stated depth will require shoring or larger excavated areas to insure worker safety, and such work,
especially extensively excavated areas, may pose a threat to the Shot Tower. In summary,
archaeological field work will yield data needed to fine-tune geomorphological observations and
interpretations.
Archaeological excavation units will be laid out adjoining the interior and exterior walls of the
Shot Tower. A single unit measuring at least 2 meters by 1 meter adjoining and oriented
perpendicular to the river side, exterior foundation wall will be excavated in order to expose the
presumed lOur-stage stone spread footing, which supposedly measures 6 feet wide. The unit may
be larger in horizontal area if the geomorphological data suggests that a thick layer offlood borne
sediments bury a substantial segment of the once exposed column base. Ifneeded, an expanded
unit will accommodate safety considerations related to depth of excavation; however, practical
considerations will dictate the maximum size of the area over which the unit can be expanded: the
unit can be only so large because it is bound by the Shot Tower wall and the concrete encircling
foundation/wall.
The exterior unit will be excavated manually using shovels and trowels, and all sedimentary
deposits identified as post-dating] 91 I, the year the Tower burned and was no longer used as a
fire watch tower, will be screened through one-quarter inch hardware mesh cloth. A finer mesh
cloth will be used if lead shot measuring less than one-quarter inch in diameter is identified
within a level/stratum.
On the interior of the Shot Tower, geomorphological derived data will guide the excavation of a
single unit adjoining one of the three walls not associated with the doorway. The size of the unit
will be comparable to that of the exterior unit, and will be excavated in a similar fashion.
Deposits excavated from within the Shot Tower will be screened outside of it if researchers
determine that all or a portion of them require screening. If the well feature in question was
exposed when the structure was recorded as part of a Historic American Buildings Survey
(HABS) during circa] 934, sediments now burying the well date to the mid- I 930s or later, and
may not require screening. Again the unit can be expanded only to a size that safely
accommodates the archaeologists excavating it.
During the excavation of a unit, standard archaeological practices will be followed. ] f natural
stratigraphic units are identified, they will be excavated as such. In the absence of natural
stratigraphy, fill will be removed as arbitrary levels dictated by the nature of the deposit and how
it is interpreted by the geomorphologist All artifacts recovered from a unit will be collected,
given a unique identi/)'ing number, and removed to a laboratory facility for analysis. Field notes
will be taken as a unit is being excavated, and once a unit is completely excavated, one or more
unit walls will be profiled, exposed structural features will be mapped, and photographs will be
taken. A unit will be backfilled after it has been thoroughly documented.
2.5 Laboratory Analyses
Depending upon their nature, project related soil cores, artifacts, maps, records, notes, and other
documentation generated during field investigation of the Shot Tower will be brought back either
to the GLARe laboratory or that of the geomorphologist for analysis. Laboratory staffwill
process artifacts and samples according to standard archaeological or soil laboratory procedures.
Archeological field notes, maps, and photographs will be reviewed and prepared for report
publication, while artifacts will be cleaned, analyzed, and prepared for curation. Soil cores will be
cut open, examined, described, and interpreted. Sediments may be screened for archaeological
materials if such an action is deemed appropriate, and specific segments of cores will be selected
for further analysis that evaluates sediments for contaminant lead content levels. Up to 20
samples will be sent to the University of Wisconsin-Madison Soil and Plant Analysis Laboratory
for lead content levels.
2.6 Report Preparation
Upon completion of the analyses and interpretation of geomorphological and archaeological data,
an Archeological Documentation Report (Report ofInvestigations) will be prepared according to
the scope of work identified in the "Dubuque Shot Tower Archeological Investigation RFP". The
report will discuss the methodology/procedures used to investigate the Shot Tower, the results of
such investigation, and recommendations for the cultural resources management of the structure
and any associated archeological components.
2.7 Curation
Project related artifacts and documentation are to be cumted at a repository of the City of
Dubuque's choosing. The City may select a local repository or that at the University oflowa. If
the University of Iowa is selected as the repository, the cost will be $300 cubic foot of material as
well as a $20 site accession fee. Given the nature of the site and the limited amount of excavation,
the assumption is that not more than 1.5 cubic feet of curation space will be needed for artifacts
and project documentation.
3.0 HAZARDOUS WASTE OPERATIONS AND EMERGENCY RESPONSE
(HAZWOPER) PERSONNEL
GLARC archaeologists will be working closely with geomorphologists who have successfully
completed a 40 hour Hazardous Material Emergency Response tmining course followed by an 8
hour refresher class. The archaeologists and geomorphologist will be working under similar
conditions, and the two teams will discuss health/safety precautions, for example, gloves, hard
hats, respirators, and protective clothing, required to minimize health risks involved with
handling soils potentially contaminated with lead or bird guano, and working in a confined space.
4.0 CONSULTATION
A project time schedule with start-up, field work completion, and report submittal dates has not
been provided, although it is asswned that the Dubuque Shot Tower Project will be performed
sometime during Mayor June. [fthis is the case, then prior to field work, all parties involved with
the study will be brought together to discuss the project during an agreed upon date within two-
to-three weeks after the contract is signed between the City of Dubuque and GLARC. GLARC
will be responsible for organizing the meeting, which mayor will include the following parties or
their designated representative(s): the State Historical Society oflowa (SHSI); the National Park
Service (NPS); the City of Dubuque; the Iowa Department of Natural Resources (IA DNR); the
Iowa State Historic Preservation Office (SHPO); the Archeological and Cultural Heritage
Interpretation Program at Lums College of Dubuque (Loms College); commercial interests, such
as the owners of the Peavey Warehouse, that may be affected by the work; Strata Morph
Geoexploration, Inc. (Stmta Morph); and GLARC.
GLARC and Stmta Morph will present the research design for the study and will look for
comments/suggestions from SHSI and NPS, which are respectively funding the study with
Historic Resource Development Program and Save America's Treasures grants; the City of
Dubuque, which received and is administering the grants; and the SHPO, which will review the
final report in terms of compliance with federal historic preservation legislation. Remaining
parties--IA DNR, Loms College, and commercial interests-may determine that they do not
need to attend the consultation meeting and decide they can convey input on a limited bases via
letter/telephone/e-mail. The IA DNR is included in the consultation process because the
archaeological investigation must be coordinated with a Phase II environmental survey oriented
toward determining if residual environmental contaminants from the historical production of lead
shot exist at the site. Loras College is included as a consulting party because the project RFP
requires that students in the College's Archeology and Cultural Heritage Interpretation Program
be offered an opportunity to participate in the Shot Tower study. Finally, commercial interests,
especially the owners/operators of the Peavey Warehouse, that use Commercial Street, which
passes by the Shot Tower, are included in the consultation because archaeological field work
needs to be coordinated to avoid peak periods of truck traffic in the area.
Upon completion of the field work, a consultation meeting will be scheduled in order for the
results ofthe study to be presented and discussed before a draft report is produced. GLARC will
again take the lead for contacting consulting parties and scheduling this meeting, which should
take place two-to-three weeks after the field work is completed.
5.0 PROJECT SCHEDULE
Assuming a formal notice to proceed by "' It 7 /04 , the schedule, indicating completion dates
no later than, will be as follows: I I
Curation
Days from Notice to Proceed
o days
28 days
28-35 days
28-35 days
42-49 days
54 days
Within 30 days upon receipt of
comments
Within six months upon acceptance of
final report
Task
Notice to Proceed:
Archival and Background Research
Archaeological Field Studies
Geomorphological Field Studies
Laboratory Analysis
Draft Report Submittal
Final Report Submittal
Consultation
As needed throughout the project, to be
concluded within three months
following acceptance of the tinal report
6.0 COMPENSATION AND INVOICING
6.1 Compensation
The compensation for this work is $14,315.47. This is a lump sum amount.
6.2 Invoicing
GLARC will bill the City of Dubuque monthly with net payment due within thirty (30 days).