Archaeological Site Mitigation Work
What is Involved

Site Avoidance

Potential damage to archaeological resources can be mitigated in
several ways.  The California Environmental Quality Act (CEQA)
prefers that significant cultural sites be preserved intact
(undisturbed).  This can be accomplished in a couple of ways:

  1. By designing development to incorporate archaeological sites
    as part of open space or parklands (deeding such areas to a non-
    profit land conservancy group can also provide a nice tax
    break).  or
  2. By placing fill soil over the archaeological site and building
    atop the fill (the fill must be thick enough to incorporate all
    utility, drainage, and footing trenches).  

This is usually the least expensive mitigation alternative and the
most frequently used.

Data Recovery

If it is impossible to design the project away from the resource, or if
fill placement is not an option (such as in steep slope areas), then
CEQA requires that the information contained in the resource be
gathered before the damage takes place.

This is called "Data Recovery Mitigation" and involves the
archaeological excavation of a sample from the proposed area of
disturbance.  The size of the sample depends on the content of the
resource.  An archaeological site where only one activity was taking
place (such as a quarry site where only stone tool manufacture
occurred) may only require a 2% to 3% sample of the area of impact.  
A village site where stone tool making, food preparation, housing,
and ceremonial activities took place may require an 8% or 10%
sample of the area of impact.
Site maintained as a public service by Archaeological Research, PO Box 1353, Lucerne, CA 95458.
Mitigation Plans
History and Prehistory of Lake County
and Beyond
NA Resources
Light soil used as fill over 9,000 year old prehistoric site before house construction.
3 finished homes built atop fill over prehistoric site
Combination Mitigation Plans

Often it is possible to place fill over much of the site, however utility trenches may require
that small areas be damaged.  In such cases only those areas where direct damage will take
place are sampled.

In the photos at right, 4 homes and 3 duplexes were constructed atop the largest prehistoric
village site in Morro Bay.  The top photo shows the placement of fill over the archaeological
site.  The lower photo shows the completed project.  Damage to the archaeological site only
occurred where water and sewer lines had to connect to existing mains under the street.    In
these areas we conducted data recovery excavations before the connection trenches were dug.

Products Produced

Mitigation Plan

Often a planning agency will require a mitigation plan prior to issuing the construction
permit.  We will work with your architect and/or engineer to come up with the best mitigation
alternative for your project.  We will provide you or your contractor with 3 copies of the
mitigation plan (to be kept with your permit paperwork and filed with the planning agency).

Final Mitigation Report

Once the archaeological mitigation work is complete and materials have been analyzed, we
provide you or your contractor with 4 copies of the Final Mitigation Report (three for the
planning agency and one for your personal files).  In addition, a copy is sent to the California
Historical Resource Inventory office so the state files can be updated.

For more information concerning the legal requirements, click the "CEQA Law" button.
When Required

If your project will be constructed on or near a significant historic or prehistoric
archaeological site, the planning agency (city or county planning department) will likely
require that the potential damage to the historic resource be mitigated before construction
begins.  Once the mitigation has been completed, they may also require that an archaeologist
monitor grading or trenching to insure that significant artifacts and features (not recovered
during the mitigation) can be recorded and collected.

Archaeological Research specializes in developing mitigation plans that will allow the project
to proceed while preserving the essential nature of the archaeological resource.  We will work
closely with your architect and engineer to devise a plan that will protect the resource in the
most cost-effective way.