An Update on the Archaeological Assessment of the City of Afton
Downtown Improvements Project, Proposed Lift Station Area
By
Steven J. Blondo, MA and Kelly Wolf, MA, Blondo Consulting, LLC
June 27, 2016
On May 16-17, 2016 Blondo Consulting, LLC (Blondo Consulting) completed a follow-up Phase
II in the originally proposed sanitary sewer lift station area and along the east side of the
existing levee for the City of Afton Downtown Improvements Project. Melissa Cerda of the
MIAC visited the site on May 17. Following this follow-up Phase II, the originally proposed lift
station area was moved to a location south and east of the originally proposed location (see
attached map). This new location was visited by Blondo Consulting staff on May 25. The results
of these visits are contained in this report.
Proposed Lift Station Area
Phase II Testing
An additional six shovel tests and one one-meter by one-meter test unit was completed in the
area of the originally proposed lift station on May 16-17, 2016. The attached map shows
locations of all of the archaeological testing completed in this area by Blondo Consulting. Shovel
Tests 22 through 26, and 29 were completed in the northwestern corner of this area in a fivemeter grid. All of these shovel tests revealed evidence of disturbance within the soils above the
5YR3/4 coarse sand subsoil. This disturbance is reflected in somewhat compacted soils and
mixed artifacts present including glass, metal, plastic, and styrofoam. Subsoil was present at
approximately 40 to 50 centimeters below the surface in all of these shovel tests. Shovel Test
29 was only excavated down to approximately 15 centimeters and demonstrated clear evidence
of a past driveway including gravel fill over landscaping fabric. Shovel Tests 22 through 24
establish a northern boundary for the National Register of Historic Places eligible historic features
identified previously in Test Unit 1, and Shovel Tests 20 and GPR A, which is now recorded as
site 21WA0116. This will be discussed in more detail in the next section.
Test Unit 2 was placed on the north central portion of the originally proposed lift station area,
to the north of a driveway-like graded area that exists in the central portion of the area aligned
north-south from the existing parking area. The test unit shows heavily compacted soils with a
small amount of artifacts present. Artifacts are mixed, showing disturbance and includes
concrete, styrofoam, plastic, glass, ceramic, and metal. Potential flakes were also recovered in
levels 1 and 2 that have been determined to be precontact lithic flakes; however, it is impossible
to know the context of these flakes due to the disturbance of this area. Some gravel was also
present. Levels 1 through 3 were excavated to approximately 30 centimeters below the ground
surface. Due to the heavy disturbance and soil compactness, a shovel test was completed in the
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center of the unit. The heavily compacted soils continued until approximately 35 centimeters
below the surface. Mottled clay sand was present from 35 to 50 centimeters below the surface
with some bioturbation visible. Typical subsoil was present beginning at approximately 53
centimeters below the surface consisting of 5YR3/4 coarse sand. The shovel test was concluded
at 70 centimeters below the ground surface. Artifacts were not present in the subsoil.
Following this additional Phase II, the proposed lift station was relocated to the south of the
parking lot, and west of the levee. Blondo Consulting completed a pedestrian survey and took
photographs in this new area. Currently this area consists of heavy disturbance from
landscaping and levee construction and includes a low area where a culvert discharges with
standing water when it rains, a raised and leveled manicured lawn, and landscaping retaining
walls. Please see attached photos and maps for more detailed locations.
NRHP Eligible Historic Features
Through the Phase I and II testing of the originally proposed lift station area, Blondo Consulting
determined that a previously unknown archaeological feature was present that included historic
artifacts within an intact feature. Archeao-Physics, LLC identified this subsurface feature
through the initial geophysical testing and Blondo Consulting tested it further by excavating
archaeologically with shovel testing and a test unit (Test Unit 1). This newly identified historic
site has been recorded as 21WA0116 with the Office of the State Archaeologist. It is Blondo
Consulting’s recommendation that site 21WA0116 is eligible for inclusion in the National
Register of Historic Places under Criterion D for the potential to yield further information about
early Afton and early Minnesota history. Historic contexts developed by the Minnesota SHPO
that may be associated with this site include:
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St. Croix Triangle Lumbering (1830s-1900s)
Early Agriculture and River Settlement (1840-1870)
Railroads and Agricultural Development (1870-1940)
The Washington County Historical Society has also developed historic contexts and this
historic site may be associated with any of the following:
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Townsite Development (1849-1965)
Tourism and Recreation (1849-1969)
Agriculture (1840-1960)
Further evaluation of site 21WA0116 would help to narrow the association with these historic
contexts and would further define this historic site. At this time, the proposed lift station has
been relocated to avoid any impact to this eligible Historic Property; therefore, continued
archaeological investigation of site 21WA0116 is not required. The site boundaries of 21WA10,
the Rattlesnake Mound, and historic site 21WA0116 will be fenced off during construction to
avoid any effects to either site. An Unanticipated Discoveries Plan will also be in effect during
the construction.
East of Levee
Blondo Consulting also completed additional testing east of the existing levee to test observed
mound-like landscape features. Testing completed in the largest mound-like landscape feature
showed heavily mottled soils with artifacts including glass, coal, clinker, charcoal, metal, and
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ceramics. These soils and artifacts are consistent with the presence of an old railroad corridor.
Shovel testing was concluded at approximately 95 centimeters below surface due to impassible
heavy cobbles and clay soil. An additional mound-like landscape feature was tested just adjacent
to the first one. This landscape feature was consistent with a sand bar and had various historic
artifacts on the surface. Shovel testing showed natural soils with mottled sandy loam and some
historic artifacts present, then transitioning to a sandy clay loam and continuing to very damp
sandy clay. Water entered the shovel test at approximately 80 centimeters.
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Photo 1: Of relocated proposed lift station, from existing parking lot, facing east.
Photo 2: Of relocated proposed lift station location from the top of the levee, facing
south.
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Photo 3: Of relocated proposed lift station from the top of the levee, facing west.
Photo 4: Of current drainage and landscaping in the relocated proposed lift station
area, facing north.
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Photo 5: Of current drainage and landscaping in the relocated proposed lift station
area, facing south.
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