Horse Creek Stewardship Program

Client: The Mosaic Company (Mosaic)

Location: DeSoto, Hardee and Manatee Counties, Florida

Summary: As a result of proposed phosphate mining operations by The Mosaic Company (Mosaic) and a series of legal challenges to the permits required for such mining, Mosaic and the Peace River Manasota Regional Water Supply Authority (PRMRWSA) executed a settlement agreement to ensure that phosphate mining would not have negative impacts on Horse Creek, located in DeSoto, Hardee, and Manatee Counties. A principal component of that agreement was the creation of the Horse Creek Stewardship Program (HCSP), which was developed by Cardno ENTRIX. Information on the physical, chemical, and biological characteristics of Horse Creek are collected during Mosaic mining and reclamation activities in the watershed in order to detect any adverse conditions or significant trends that may occur as a result of mining. In addition, mechanisms for corrective action have been developed if any detrimental changes or trends caused by Mosaic?s activities are found.

A team of Cardno ENTRIX ecologists conducts surveys of the macroinvertebrate and fish communities at four locations on Horse Creek three times a year. Macroinvertebrates are collected using the Florida Department of Environmental Protection?s Stream Condition Index (SCI) methodology, and fish are collected by seine and electroshocking. Field water quality measurements are collected at each location during each monitoring event. Comprehensive annual reports are prepared by Cardno ENTRIX that analyze results of the biological monitoring, as well as daily and monthly water quantity and quality monitoring conducted by Mosaic, USGS, and SWFWMD for exceedances of program trigger levels and general trends. In addition, Cardno ENTRIX produced a report that compiled and analyzed all available historical data collected by Mosaic, SWFWMD, USGS, and other entities on water quality, water quantity, and aquatic biology of Horse Creek. Cardno ENTRIX also serves as the liaison between Mosaic and the PRMRWSA and other members of the HCSP Technical Advisory Group, who review monthly and annual reports on the water quality of Horse Creek.