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Sediment Chemistry

Contact: Sam Noffke 517-755-7173

EGLE's report entitled "A Strategic Environmental Quality Monitoring Program for Michigan's Surface Waters" (Strategy) describes the monitoring activities that are necessary for a comprehensive assessment of water quality in Michigan's surface waters.  One important component of the Strategy is sediment chemistry monitoring.

The sediment chemistry monitoring activities are consistent with existing EGLE programs.  For example, EGLE uses the existing 5-year basin units defined by the NPDES permitting program, which includes 45 watershed units based on drainage to the four Great Lakes.  Monitoring activities in each watershed include not only sediment chemistry, but also aquatic life community evaluations, fish and wildlife contaminant studies, and water chemistry.  Integrating the sediment chemistry monitoring with the other activities, within the framework of the five-year permitting cycle, will ensure that the monitoring is closely linked with other EGLE programs and contributes to resource management decisions.

The specific objectives of sediment chemistry monitoring are to:

  1. Determine the chemical character of sediments in waters of the state, and whether sediment contaminant levels are changing over time.
  2. Identify priority locations for sediment remediation activities in Michigan.
  3. Determine background sediment chemical character of waters of the state.
  4. Determine whether new chemicals are accumulating in sediments.
  5. Evaluate the overall effectiveness of the NPDES permit program in reducing contaminant levels in sediments.
  6. Determine the contaminant anthropogenic sediment burden in inland lakes.
  7. Investigate the relationship among contaminant accumulation trends and anthropogenic and natural processes including changes in land use

The sediment chemistry element consists of two components that, in combination, provide data necessary to achieve these objectives.  These include:

  • Inland lake trends; and
  • Watershed surveys (consistent with 5-year basin cycle);

For the inland lake trends component, several inland lakes will be assessed over several years. Through 2009, a total of 44 lakes have been monitored. Of these 44 lakes, 10 were sampled twice. Sediment samples are analyzed for total mercury, trace metals (cadmium, chromium, copper, lead, nickel, zinc), total PCBs, and organochlorine pesticides such as DDT. Inland lake trend data are summarized in annual trend reports produced by Dr. Dave T. Long of Michigan State University and reviewed and approved by the Water Resource Division's Great Lakes Watersheds Assessment, Restoration, and Management Section staff.

Sediment samples collected as part of the watershed surveys are analyzed for a variety of parameters, based on local conditions and known/suspected sources.  Data collected as part of the 5-year watershed surveys are summarized in watershed reports and are entered into EPA's Water Quality database

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