Water Chemistry

EGLE's 2017 report, “A Strategic Environmental Quality Monitoring Program for Michigan’s Surface Waters,” (Strategy) identified four major goals of the Water Resources Division and listed individual objectives within each of the Water Resources Division Programs.  The Strategy was written at a time when resource constraints had forced funding and staffing for water quality programs to decrease considerably.  A Strategy Update was written in 2005 after those resource constraints were alleviated with annual appropriations of Clean Michigan Initiative funds, allowing the Strategy to be fully implemented.  Another Strategy Update was written in 2017.  The latest update, Michigan's Surface water Strategy 2025, is available on the Monitoring Overview webpage.  Beginning in 2020, the Renew Michigan Fund began providing funds to help implement the Strategy.

The Strategy has four major goals:

1. Assess the current status and condition of waters of the state and determine whether water quality standards are being met.
2. Measure spatial and temporal water quality trends.
3. Evaluate the effectiveness of water quality restoration and protection programs.
4. Identify new and emerging water quality problems.

Within each goal are specific objectives that are reached through Water Resources Division monitoring activities, including the Water Chemistry Monitoring Program (WCMP).  The primary objectives of the WCMP are to: (1) identify the chemical character of surface waters of the state and relate characteristics to Michigan’s Part 4 rules, Water Quality Standards, when applicable; and (2) determine whether the chemical character of surface waters of the state are changing over time.

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

• Fixed station trend sites in Bays (Saginaw and Grand Traverse Bays) and Connecting Channels (Detroit River, St. Clair River, and St. Marys River) (note: annual fixed station trend monitoring of 31 tributaries to the Great Lakes ended in 2013);
• A statewide water chemistry status and trends program began in 2005 using a probabilistic sampling design with 250 “PROB” stream or river sites total (50 sites monitored per year on a rotating, 5-year cycle);
• Occasional, targeted monitoring during watershed surveys (consistent with the 5-year basin cycle);
• Issue sites (TMDLs, nonpoint source issues, statewide mercury assessment, etc.).

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

All quality assured water chemistry data are entered into the Water Quality Exchange (WQX) (formerly STORET).  Data are then accessible to the public through the Water Quality Portal (WQP).   WCMP data (e.g., statewide water chemistry status and trends; fixed station trends) are summarized in reports produced periodically by EGLE's Water Resources Division (WRD). 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.  Data and reports are available upon request.  Reports are listed below.

Requests to have EGLE's Water Resources Division (WRD) monitor a particular waterbody can be made via its targeted monitoring request process.  WRD annually evaluates all the requests it receives and, in light of available funding, staff time, and demonstrable need for the data, it prioritizes which requests it can fulfill.  For more information, please visit the Targeted Monitoring Request webpage.