May 2009, Vol. 21, No.5

Waterline

New Filter Could Clean Golf Course Runoff

Agricultural engineer Kevin King is researching the potential for cleaning water from golf courses before it reaches streams and other local waterways. King, with the U.S. Agricultural Research Service (ARS) Soil Drainage Research Unit in Columbus, Ohio, is testing the ability of filter cartridges attached to drainage pipe and retention pond outlets to filter out pollutants before they reach local waterways, according to ARS.

King uses commercial cartridges filled with industrial byproducts and typical water cleansers used in drinking water treatment plants and home aquariums, according to an ARS news release.

“Byproduct materials have the capacity to adsorb or bind the pollutants,” King said. “There are a number of industrial byproducts that show promise in their ability to remove nutrients and pesticides from drainage waters.”

Materials tested in King’s filters include clinoptilolite (a naturally occurring, readily available zeolite), activated alumina, and activated carbon created from coconut shells, King said. Clinoptilolite is efficient at removing ammonia and also can remove some nitrate, he said. Activated alumina binds the phosphorus to create a nonsoluble compound, and activated carbon is used to strip out pesticides.

King has conducted filtration tests in Texas and Minnesota and is setting up a field-test facility in Ohio, the news release says. He also is testing water treatment facility residues, such as alum, to improve the ability of buffer areas to filter pollutants before they reach the drainage pipe outlets. Alum is a byproduct of the ammonia alum used for water purification, the news release says.

“Alum in the buffer strips works much the same way as a filter,” King said. The alum, delivered to the buffer zones through water treatment residual and spread in filter strips, would precipitate out phosphorus from the overland flow of water that encountered it.

King has been working on this research for about 2 years. Scientists at ARS labs in Ohio, Indiana, Minnesota, Pennsylvania, and Maryland are collaborating on the project. ARS also is beginning a larger-scale testing of several products and delivery systems that could be applied at a watershed scale, King explained.

“Using discharge rates typically found in subsurface drainage waters on golf courses,” King said, “we were about to remove greater than 50% of the soluble phosphorus and between 30% and 60% of the pesticides that were tested.”

Read more about this and associated research in the January 2009 issue of Agricultural Research magazine at www.ars.usda.gov/is/AR/archive/jan09/drainage0109.htm
 

U.S. EPA Study Locates Great Lakes Ports Threatened by Invasive Species

A new study by the U.S. Environmental Protection Agency (EPA) uses a species distribution model to determine where 14 of 58 potential invasive species could find habitat within the Great Lakes region.

The study analyzes ballast-water discharges using vessel traffic data, evaluates habitats using the Genetic Algorithm for Rule-Set Production (GARP) niche model, and reviews literature to assess the future arrival and spread of invasive species in the Great Lakes.

During the 1830s, the sea lamprey became the first invasive species to enter the Great Lakes, and since then, at least 185 other species have invaded the area, according to EPA. The St. Lawrence

Seaway opened in 1959, beginning the release of ballast water from transoceanic vessels. Ballast water from commercial shipping has been identified as the primary way nonindigenous species have entered the Great Lakes, according to an EPA report.

EPA identified 58 species, with 28 already established in the area, as having a moderate or high potential to spread and cause ecological impacts to the region. The GARP model requires at least 30 spatially unique occurrence points to develop predictions of where the invasive species would appear. Only nine of the 30 potential invasive species had sufficient data to be modeled, according to EPA. The agency’s Great Lakes National Program Office requested that an additional five species be included in the study, yielding a total of 14 species modeled in the study.

Based on model and species depth tolerances, Lake Erie and the shallow water areas of the four other Great Lakes are the most vulnerable to invasion by the 14 modeled species, the report says.

Analysis of ballast-water discharge data of vessels entering the Great Lakes by the St. Lawrence Seaway revealed that the original source of most ballast-water discharges came from 58 different ports predominantly located in Canada and Western Europe. The Great Lakes ports at Toledo, Ashtabula, and Sandusky, Ohio; Gary, Ind.; Duluth, Minn.; Milwaukee and Superior, Wis.; and Chicago are at greatest risk for nonindigenous species invasion. The ports of Duluth, Toledo, and Superior account for 86% of the total volume of ballast water discharged into the Great Lakes, the report says.

This assessment demonstrates that successful invasions are best predicted by knowing the number of individual species entering a new area and matching similarities of the invaded area to the native range of the species. The study supports the need for detection and monitoring efforts at ports identified for greatest risk and demonstrates the importance of understanding invasion biology. Since early detection is critical to managing invasive species, EPA hopes that the report will help focus monitoring activities.

“If it is not possible to eliminate the transport of nonindigenous species to the Great Lakes, the next best alternative is to monitor for the arrival of potentially invasive species and to control their spread as soon as they arrive,” according to the report. For more information, see the report, Predicting Future Introductions of Nonindigenous Species to the Great Lakes at http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=190305.


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