Friday, March 13, 2009

Chloride - Sulphate - TDS Water Quality Standards in Iowa

The Iowa Department of Natural Resources (DNR) is moving forward on revising Iowa’s water quality standards. Water Quality Standards are the regulatory standards that apply to streams, rivers and lakes. Water Quality Standards consist of three components:

  • Designate the use or uses of the waterbody
  • Set the water quality criteria for protecting those uses
  • Protect and maintain existing water quality

Recently, the DNR began to compile all research related to toxicity of total dissolved solids (TDS), chloride and sulfate in order to update and develop criteria for these parameters. Certain data gaps were identified in the existing data sets which resulted in IDNR conducting some new toxicity tests.

With the availability of new toxicity data, IDNR believes that the minimum data requirements are now met to propose numeric criteria for chloride and sulfate. IDNR plans to also reevaluate the current interim approach for total dissolved solids criteria. The Department is planning on discussing this approach as Information item at the April Environmental Protection Commission meeting.

Caltha LLP provides expert consulting services to public and private sector clients nationwide to address water quality standards, wastewater permitting and assessing potential impacts of chemicals in the aquatic environment.

Caltha LLP Aquatic Toxicology / WQ Standards Services Website