Alcoa seeks approval to boost discharge of pollutants into Mississippi River by 24 percent

Alcoa's Davenport Works wants to increase the amount of pollutants it can discharge into the Mississippi River by 24 percent to accommodate higher quantities of oil/grease, chromium, zinc, cyanide and other suspended solids generated by expansion of the Riverdale plant to serve the automotive aluminum market.

The company is seeking modification of its National Pollutant Discharge Elimination System (NPDES) permit issued by the Iowa Department of Natural Resources (IDNR). The permit revisions, if approved, would allow the plant to discharge a combined average of 548 pounds of pollutants each day into the river. That's an average of 106 pounds per day more than the plant's current permitted discharge.

Based on the plant's 312 production days each year, the change would permit the plant to dispose of an additional 33,000 pounds of those pollutants into the river annually.

A public notice about the company's "Antidegradation Alternatives Analysis" was published August 1 by Aloca, and the public can submit comments to the company until Aug. 30. The email address to send comments is: The company mailing address is: 4879 State St., Bettendorf, IA 52722.

CLICK download a copy of the company analysis in support of higher pollution discharges. After the company completes its own analysis and obtains public input, it is expected to file the request to increase the plant's current NPDES discharge limits with the IDNR.

A similar modification in 2012 was rejected by the IDNR because the permit request included higher aluminum discharge amounts. The Mississippi River in Pool 15 already is classified as "impaired" by aluminum pollution, and consequently, the IDNR rejected the company's request.

The company's new antidegradation analysis states Alcoa is not seeking any change in the amount of aluminum it discharges in to the Mississippi. However, it is unclear how the plant will remove aluminum pollutants from its discharges since it does not propose any expansion of the plant's existing water treatment facility.

An email request for clarification on how the plant plans to limit aluminum discharges while boosting production and using the existing water treatment capacity was not answered.

The plant also did not respond to a question by asking why the plant's $300-million expansion to produce aluminum for the automotive market did not include added treatment capacity for the increase in water-borne pollutants.

"We will be following our normal procedure and will respond to all questions/comments at the end of the public comment period," the company stated in its email response.

The company's analysis states the increased chemicals discharged into the river "would not result in a significant increase in pollutant concentrations," citing the Mississippi's enormous water flow of 19.9 million gallons per day past the facility. The analysis also argues expansion of the plant with its increased employment – 192 full-time jobs with an economic impact of $39.5 million – justifies the increase in pollution discharge amounts.

Because of the plant expansion, the company obtained changes to its air quality permit last year which allowed higher emissions of volatile organic compounds, which lead to formation of ground-level ozone (smog).

To assist with the plant expansion, the state of Iowa gave Alcoa $3 million in economic development incentives.

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