Water Chemistry


Contact: Jeff Varricchione 517-284-5557

In 1997, the Department of Environmental Quality (DEQ) completed a report entitled “A Strategic Environmental Quality Monitoring Program for Michigan’s Surface Waters” (Strategy).  This Strategy describes the monitoring activities that are necessary for a comprehensive assessment of water quality in Michigan’s surface waters.  One component of the Strategy is expanded and improved water chemistry monitoring.

Historically, funding reductions as well as limitations in analytical quantification levels have restricted the overall effectiveness of the DEQ water chemistry monitoring efforts.  The number of long-term water quality sites assessed by DEQ declined from over 100 in the late 1980’s to just 13 on the Detroit River and 8 on Saginaw Bay in 1997.  However, the passage of the Clean Michigan Initiative in 1998, and subsequent appropriations by the State Legislature since Fiscal Year 2000, has resulted in a substantial funding increase for the implementation of the Strategy, which includes several water chemistry monitoring activities.  In addition, recent technological advances, especially low-level analytical techniques for metals and organic chemicals, now make it possible to collect high-quality water chemistry data that are directly relevant to priority environmental issues at a reasonable cost.

The enhanced water chemistry monitoring is consistent with existing DEQ programs and activities.  For example, the DEQ 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 water chemistry, but also macroinvertebrate and fish community evaluations, fish and wildlife contaminant studies, and sediment chemistry.  Integrating the enhanced water 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 DEQ programs and contributes to resource management decisions.

The specific objectives of water chemistry monitoring are to:

  1. Determine whether surface waters are suitable for aquatic life, wildlife and human health, based on water quality standards.
  2. Determine whether surface waters are safe for agricultural use.
  3. Determine whether nutrients are present in surface waters at levels capable of stimulating the growth of nuisance aquatic plants/algae/slimes.
  4. Determine whether water quality is changing with time.
  5. Provide data to support Total Maximum Daily Load (TMDL) development, the NPDES permit program and venting groundwater mixing zone determinations.
  6. Evaluate the effectiveness of DEQ programs in protecting water quality from conventional and toxic pollutants.
  7. Identify waters that are high quality, as well as those that are not meeting standards.
  8. Identify new chemicals that impair, or have the potential to impair, waters of the state.

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

  • Fixed station trend (Saginaw & Grand Traverse Bays, connecting channels, 31 tributaries);
  • Watershed surveys (consistent with the 5-year basin cycle);
  • Minimally impacted sites;
  • Issue sites (TMDLs, nonpoint source issues, statewide mercury assessment, etc.); and
  • Annual grants to local governments.

Water samples generally are analyzed for nutrients, conventional parameters (temperature, conductivity, suspended solids, pH, dissolved oxygen), total mercury, and trace metals (cadmium, chromium, copper, lead, nickel, zinc).  A much smaller number of samples are analyzed for organic contaminants such as PCBs and base neutrals.  Other parameters may be included as appropriate at specific locations.  Data are reviewed each year to determine whether additional parameters should be added, removed, or analyzed at a greater or lesser frequency.

All water chemistry data are entered into the STORET database.  Fixed station trend data are summarized in reports produced by the WD (see links, below).  Data collected as part of the 5-year watershed surveys will be summarized in watershed reports.  Data collected as part of TMDL sampling will be summarized in individual reports prepared for each applicable waterbody.

Related Links


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