Alter Trading Corporation operates metal recycling facilities in the Midwest. Braun Intertec has been retained by Alter to provide a variety of environmental services.

We completed an ecological risk assessment and coordinated an Environmental Assessment Worksheet (EAW) with the City of St. Paul to expand Alter’s existing metal recycling operation. The ecological risk assessment employed generic, conservative models and assumptions to approximate potential risks.

The assessment identified the chemicals emitted by the facility that are most likely to adversely impact ecological receptors. It identified potential receptor organisms and determined likely exposure points, including direct exposures to air, soil and surface water. Where possible, quantitative estimates of potential ecological risks were estimated for each major exposure pathway.

Challenges

The ecological risk assessment evaluated risks associated with operating the metal shredder due to air releases from raw materials handling and the facility stacks including deposition to soil, surface water and sediment. A characterization of habitats and terrestrial and aquatic species close to the proposed site (adjacent to the Mississippi River) was conducted that considered threatened and endangered species.

The primary ecological receptors of concern were aquatic organisms in the Mississippi River. In addition, potential impacts to terrestrial receptors such as plants, earthworms, birds and small mammals were evaluated when the exposure assessment showed a significant potential pathway.

Solutions

We prepared applications for air quality permits, both for operating and expanding Alter’s existing St. Paul facility. Additionally, we performed particulate dispersion and deposition modeling and submitted a report summarizing the analysis to the Minnesota Pollution Control Agency (MPCA).

The analysis completed for the application and modeling pertaining to the expansion was complicated by the close proximity to the site of a PM10 (particulate matter less than 10 microns) non-attainment area and the lack of published emission factors for the proposed process.