Credible Data - References

Credible Data is a program that classifies surface water monitoring performed by watershed groups, state agencies, schools, local volunteers and other organizations. Ohio EPA uses the data submitted under the program in ways prescribed by State law.

Parameters Sampled and Testing Methods

Level 1 and Level 2 Data

U.S. EPA has conducted national surveys to determine the most frequently tested parameters used in citizen based voluntary monitoring programs. To ensure that data on these commonly sampled parameters is credible for its intended use, refer to the link below to identify some of the sampling and analytical methods suitable for Level 1 and Level 2 projects.

Commonly Sampled Parameters

  • Acidity
  • Conductivity
  • Phosphorus
  • Turbidity
  • Benthic insects
  • Alkalinity
  • Dissolved Oxygen
  • pH
  • Total suspended residue
  • Stream flow
  • Ammonia (as N)*
  • Nitrate
  • Temperature
  • Bacteria*
  • Water transparency


* This parameter is only available using Level 2 methods.

Examples of Acceptable Analytical Methods

Level 3 Data

Level 3 studies could involve the sampling for a wide variety of parameters. Analytical methods must adhere to those published in any one of a number of commonly recognized method manuals. See paragraph (C) of rule 3745-4-06 [PDF 25K].