Introduction to CRM Part 4: Evaluating a Site

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Figure 1. Positive shovel test that contained lithic debitage.

When we identify a site, we conduct further evaluative testing to determine the type, character, and extent of the site. This is done according to government guidelines, and depends on the type of site, and the type of landform. If the landform allows for it, testing occurs in each cardinal direction or in a grid. Some sites are found on ridges or point terraces, and so in these cases, it is not possible to test in all directions (Figure 1).

Tree Time’s standards are that there must be three negative tests spaced at most 10 m apart in each direction from any positive. Sometimes additional tests are required in order to determine the significance, the size, and type of the site. For example if none of the evaluative tests were positive, further testing might be done at closer intervals to better determine the significance of the site. In addition to rigorous note taking, we also map and photograph the site (Figure 2).

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Figure 2. Vince taking notes at a site.

The evaluation of the site is an important step for two main reasons. The first is to enable the government to maintain an accurate site database and to better inform future researchers of the size and type of sites are in the area (Figure 3).

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Figure 3. We are evaluating an historic site by flagging artifacts with red flagging tape.

Secondly, in this stage we determine the extent and significance of the site. If a client decides to avoid the site, delineation allows us to more precisely buffer the site. This is important because it allows the development to occur as close to the original plan as possible while still avoiding impacts to the site. In addition, if a client chooses to mitigate their impacts to the site through excavation, a more detailed evaluation of a site allows us to better predict the productivity of the site, and to render cost estimates of any mitigation work more accurately.

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Figure 4. Buffer flagged around the site with orange flagging tape.

Once we have surveyed our targets, evaluated any sites we have found, and have finished our notes, it is time to return to the office (Figures 5 and 6).

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Figure 5. Reid is finishing his notes before we move onto another target.
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Figure 6. After a long cold day, Brittany heads back to the office.
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Introduction to CRM Part 3: Archaeological Survey

Using information compiled in the office, the next step of an HRIA is to leave the comforts of home behind and to venture into the field. Although there is a perception of archaeologists working at large excavations, often dressed in khakis and maybe wearing a fedora, archaeological survey is the most common type of field work in the CRM sector. So for now, we will focus on archaeological survey and discuss archaeological mitigation in an upcoming blog.

The purpose of an archaeological survey is to visit the high potential target areas we identified in our background research and GIS review in order to see if there are any historic or archaeological sites. We travel to these high potential locations using various means of transport including trucks, ATVs, Argos, the occasional helicopter for the most remote locations, and a lot of hiking (Figures 1 and 2).

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Figure 1. Teresa and Vince in an Argo travelling to target areas.
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Figure 2. Archaeology happens in all weather as Teresa and Brittany hike in snow to our target areas.

When we arrive at these locations, we use experience and expertise to determine if the landform has potential for archaeological and historic sites. For example, is this spot flat and dry? Would we like to camp or hunt from here? High, dry areas, and spots that have nice views are often tested. In fact sometimes we identify a site in the exact spot where we dropped our gear for lunch, as we naturally tend to stop on the best part of the landform (Figure 3).

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Figure 3. Our gear placed at a positive shovel test, flagged with red flagging tape.

 

The most common method of subsurface sampling that we use is screened shovel tests (Figure 4). This means we dig holes about 40 cm square and 30 to 40 cm deep and screen all of the sediment in portable screens. If there are any tree throws or surface exposures, we also conduct opportunistic examinations of these for artifacts (Figure 5).

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Figure 4. Matt is shovel testing.
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Figure 5. Picture of a tree throw that allows for opportunistic sampling.

There are several different sampling strategies that we use, these include systematic, semi-systematic, and judgmental testing. Systematic testing is the term we use when we place tests using a set interval, for example digging a test every 10 m along a landform. For judgmental testing we do not use a set interval instead we place shovel tests on the best part of a landform based on our past experience and conceptual models of how people lived on different types of landforms. Finally, semi-systematic testing is a combination of the previous two. For this method we place tests on the best locations of a land-form while trying to maintain a certain overall density of testing.

The shape of the landform helps determine what type of sampling strategy to use to test a target. A long uniform ridge might be better suited for hybrid or systematic testing, while a hillock might be more often tested in a judgmental manner (Figure 6).

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Figure 6. Brittany testing a target using a semi-systematic strategy.

If the tests are negative, then we write our notes and move on to another location to survey. However, this does not mean that we can definitely say there is not a site at the location. Negative results only reduce the chance there’s a site at a location. To be 100% sure, we’d have to do a lot more excavation (Figure 7).

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Figure 7. Although a nice area near water, we did not identify a site here.

On the other hand when we do identify a site, then we stay at the location to undertake further evaluative testing (Figure 8).

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Figure 8. Vince is very happy after identifying a site when he found a point in a shovel test.

Introduction to CRM Part 2: Development Screening and Project Planning

The first step of a historic resources impact assessment (HRIA) happens in the office. Once we have the plan for a development, we need to assess whether the footprint will impact any recorded sites or if it has the potential to impact any unrecorded sites. We use our experience and knowledge of archaeology, GIS data, and databases of recorded sites in order to identify high potential areas that might have any archaeological and historic resources (Figure 1). Although this stage of archaeology does not capture the imagination of the public and isn’t very exciting or glamorous, it is the most important part and the foundation of our work.

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Figure 1. Corey is targeting areas of high potential using QGIS.

High potential areas vary by region, depending on the geography and the history of the area. Generally areas that people would camp or travel through are considered high potential; these include well-defined landforms and areas near water. We also take into account the environment of the past. For example, shorelines fluctuate, and rivers and streams may change course or dry up. Areas near water generally have higher potential because they were used as a method of transport, offered fishing opportunities, and, of course, they were also a source of fresh water (Figure 2).

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Figure 2. View from an archaeological site looking towards a lake.

Sometimes a development plan will conflict with a previously recorded site. In this case, we can recommend either that the development plan be changed to avoid the site, or that impacts to the site be mitigated by excavation. If there are no recorded sites in the footprint, but there are areas that we think are likely to have sites, we recommend field survey. Using GIS data and the research that we have complied concerning the area around the developmental footprint, we create targets of high potential areas to survey in the field. The next step takes us out of the office and into the field.

Introduction to CRM Part 1: Cultural Resource Management

Cultural Resource Management (CRM) is undertaken in many different countries all over the world and it can go by just as many names, Contract Archaeology, Consulting Archaeology, Compliance Archaeology, and Heritage Resource Management (HRM) to name a few. Whatever CRM is called, the underlying purpose is always the same. These archaeologists engage in the protection, preservation, and professional management of archaeological and historic sites. In Canada, this means that we help minimize any impacts planned developments might have on a province’s archaeological and historic resources. These resources include archaeological sites containing artifacts such as stone tools and animal bones (Figure 1), and historic sites consisting of structures like cabins or artifacts like metal tools (Figure 2).

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Figure 1. A stone knife that was recovered from a pre-contact (prehistoric) site.
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Figure 2. A cabin that we discovered during an archaeological survey.

Using our experience in archaeology and research, along with computer programs like GIS, we review development plans and identify recorded sites and areas that have high potential to have archaeological and historical resources (Figure 3). This most commonly results in an archaeological survey of the high potential areas. Another option is to move a development or minimize the potential impacts by changing the way the development will be done.

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Figure 3. Corey is identifying high potential areas using GIS.

Next, we go into the field to survey the high potential areas (Figure 4). In forested parts of Alberta we do this by shovel testing. If we identify a site, we dig more evaluative tests to determine the nature and extent of it. This allows us to contribute information for the government and other researchers concerning the size and type of sites in the area. In addition, it allows us to more precisely buffer the site for our clients so development can occur close to the site without impacting it. It also makes it possible for us to better evaluate the significance of the site and to render cost estimates for any mitigation work much more accurately.

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Figure 4. Teresa is taking notes about a site.

 

Once we complete the field survey, we return to the office. This is where we catalogue the artifacts and compile a report for our clients and the government.

Archaeology Risk Management Plans?

 

In a previous blog post, I wrote about how remediation and archaeological impact assessment pose very similar problems, from a technical perspective. In both cases, there is something in the ground, and we need to figure out where, how much, and what to do about it. My impression is that remediation is well ahead of archaeology on both the technical and regulatory fronts. This is actually a good thing. It means we can borrow and adapt methods and procedures that have been proven to work.

Alberta Environment and Parks (AEP) recently released a draft Risk Management Plan guide to update their guidance on the requirements for Risk Management Plans for Exposure Control. Exposure Control is an alternative to traditional remediation of contaminated sites when full remediation is not technically feasible. AEP’s preferred approach to contamination is remediation (removal of the contaminants), but they’re willing to entertain leaving contaminants in the ground as long as an adequate risk management plan is in place. Both Exposure Control and full remediation have parallels in archaeology; exposure control is very similar to avoidance and remediation is akin to mitigative excavation. In archaeology, the preference is for avoidance over mitigation, because excavation is destructive and archaeology is a non-renewable resource, so we opt for site avoidance whenever we can. This poses a number of challenges:

  • A commitment to avoidance doesn’t provide the clear regulatory closure that site clearance or a completed mitigation does.
  • Once an archaeological site is in-situ within a crown disposition or development footprint there are no regulatory mechanisms to trigger review if development plans change.
  • Long term, theoretically perpetual, avoidance of an archaeological site requires some mechanism to ensure that commitment is communicated to future operators and owners.
  • Ongoing monitoring of hundreds or thousands of avoidance commitments would require substantial regulatory resources.

Too often, avoidance commitments are made and resources are left in-situ, only to be disturbed by later development through miscommunication or human error. The Historic Resource Management Branch of Alberta Culture and Tourism (ACT) has recognized this problem, and has begun requesting more details when proponents opt for site avoidance, but hasn’t yet developed the regulatory mechanisms to address it. Fortunately, Alberta Environment and Parks has had to deal with a lot of contaminated sites and has developed a very detailed and robust draft Risk Management Plan Guide that addresses a lot of the same risks.

AEP has identified several core components of an adequate Risk Management Plan:

  1. Administrative information, including the identification of the person(s) legally responsible to maintain and monitor the plan until the site meets remediation guidelines.
  2. A detailed background to provide the context of the site; essential to ensure that the Risk Management Plan will survive regulatory and operational personnel changes.
  3. Identification of the contaminants (resources) of concern.
  4. Identification of risks associated with the site under current conditions.
  5. A Conceptual Site Model, which is a detailed visual and written description of the site, incorporating all currently known information. (This is another tool archaeologists could borrow from the remediation world to improve how we communicate about sites.)
  6. A summary of current land-use and zoning, which are factors that can dramatically affect the level of risk to a site.
  7. Complete Delineation. Again, remediation is far ahead of archaeology when it comes to standards and methods for accurate delineation and evaluation of sites. In order to accurately evaluate risks, we need a better understanding of the site than is currently obtained at the archaeological survey (HRIA) stage.

AEP also systematically breaks down the Exposure Control Plans to ensure that they will address all of the challenges we raised above. In addition to the detailed exposure control (avoidance) methods that will be implemented, and the rationale for their selection, the Plan has to include:

  1. Timelines and organizational requirements to ensure continuity.
  2. An evaluation of the remaining risks.
  3. A monitoring plan, which is explicitly the proponent’s responsibility, in perpetuity, and must include a schedule and reporting and record keeping mechanisms.
  4. A contingency plan in the event of failure.

Finally, an adequate Risk Management Plan includes a communication plan to ensure that all stakeholders (such as regulators, land owners, municipalities, and First Nations) are aware of the plan, informed of monitoring results, and notified in the event of a failure.

As archaeological mitigation costs continue to rise, our ability to predict and detect the location of sites improves, and community interest in sites of all types increases, proponents will be opting for avoidance and other alternatives to mitigation more often. AEP’s Risk Management Plan model may seem overly prescriptive to archaeological professionals used to fairly open standards and a lot of regulatory freedom, but the continued occurrence of avoidance failures indicates that the current system isn’t working. Fortunately, we don’t have to reinvent the wheel. Techniques, procedures and regulatory models for the long-term management of risks on the land already exist. AEP will be releasing their final guide for Risk Management Plans in the near future. Archaeology Consultants could easily adapt AEPs template to provide our regulators with the information and tools they need to manage and monitor long-term avoidance and other innovative historic resource management options.

Picture of the Week

More than archaeology…

In addition to looking for historic resource sites when in the field we are always on the lookout for noxious weeds like these oxeye daisies. When we encounter them we report them to our clients so they can manage them appropriately. In this case the client requested that we pick them out by the roots so they could spray the area with herbicide before they went to seed.

What is a Borden Number?

The Borden System is used to provide each archaeological site in Canada with a unique identifier, called a Borden Number. These identifiers consist of two parts – four letters (formatted AaBb) and a number separated by a dash. The letters represent the Borden block which is the geographical location of the site and the number indicates the sequence when it was identified.

The Borden System was invented by Charles E. Borden with the help of Wilson Duff in 1952 at the University of British Columbia. Charles E. Borden is sometimes referred to as the “grandfather of British Columbia archaeology” despite not having a background in archaeology. He was born in New York City in 1905 and then moved to Germany as an infant where he lived until at 22 he discovered that he was an American citizen. He returned to the United States and went to university in California to study German literature. Continue reading “What is a Borden Number?”