Iowa Chloride, Sulfate and TDS Ambient Water Quality Standards

The Iowa Department of Natural Resources (IDNR) is currently proposing to amend Iowa ambient water quality standards for chloride, sulphate and total dissolved solids (TDS). In addition, they are proposing a change to the default hardness value used to calculate ambient water quality standards for many chemicals, especially metals.

The changes being proposed include the following:

• Establish numerical water quality criteria for chloride for the protection of aquatic life uses.
• Establish numerical water quality criteria for sulfate for the protection of aquatic life uses.
• Remove TDS criteria and implementation approach
• Revises default hardness level used for hardness dependent chemical criteria from 100 mg/l (as CaCO3) to 200 mg/L.

IDNR will be accepting comments on these proposed changes until August 14, 2009.

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

Draft Clean Water Restoration Act Approved By Senate Committee

The US Senate Senate Environment and Public Works Committee has approved a bill, "the Clean Water Restoration Act", that will clarify the scope of the Federal Water Pollution Control Act Amendments of 1972 ("Clean Water Act") definition of "waters of the United States". Under the draft bill, waters of the US would be defined as including:

(A) all waters which are subject to the ebb and flow of the tide;
(B) all interstate waters, including interstate wetlands;
(C) all other waters, such as intrastate lakes, rivers, streams (including intermittent streams), mudflats, sandflats, wetlands, sloughs, prairie potholes, wet meadows, playa lakes, or natural ponds;
(D) all impoundments of waters of the United States;
(E) tributaries of the aforementioned waters;
(F) the territorial seas; and
(G) wetlands adjacent to the aforementioned waters;

The draft bill specifically excludes groundwaters from the definition of waters subject to the Clean Water Act. As always, States can decide to include additional types of waters to be included as "waters of the State". Some States already include groundwater under this definition.

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