STUDY AREA AND NETWORK DESIGN

The monitoring wells are flush-mounted with ground surface to minimize interference with mowers and citrus equipment, and capped to avoid any surface contamination. - click to enlarge

The Lake Wales Ridge study area encompasses about 700 sq mi in Polk and Highlands Counties (fig 1) and includes one of the most productive citrus regions in Florida. Citrus land use covers about 25 percent of the study area. Polk and Highlands Counties have been among the top three citrus-producing counties statewide in Florida in recent years.
The Lake Wales Ridge Monitoring Network is a long-term sampling network focused on evaluating the impacts of citrus agriculture on ground-water resources. The network consists of 31 wells sampled quarterly for selected pesticides and their degradates; nutrients; and basic water chemistry. The network is intended to be a long-term monitoring effort.

 

Young citrus grove adjacent to older groves (in background) in the vicinity of a Ridge monitoring well. - click to enlarge

The design of the monitoring network is based on a randomized grid-sampling approach. Existing wells were selected based on areal distribution and shallow depth, and new wells were sited using a 3 sq mi square grid, as described by Choquette and Sepulveda, 2000. All well sites are in areas of active citrus groves on soils classified as vulnerable to leaching of pesticides to ground water. The wells are located on road right-of-ways in areas surrounded by citrus groves. The wells are positioned very close to citrus trees, and their water samples are intended to reflect the influences of crop production practices.

 

Citrus grove irrigated with drip irrigation system. - click to enlarge

                                     Sampling History