Paul D. Ryder L. R. Mills 1977 The coastal parts of Citrus and Hernando Counties, Fla., are undergoing extensive urban development along U.S. Highway 19. The Floridan aquifer, a thick sequence of limestone and dolomite , is the principal source of water supply for the coastal parts of these two counties. The construction of canals that penetrate the Floridan aquifer, deficient rainfall during 1964-75, and pumping of ground water, have caused saltwater to intrude the aquifer. A map shows the inland extend of that intrusion as of 1975. The report is based on field data collected in 1964, 1973, and 1975. (Woodard-USGS) application/pdf 10.3133/wri77100 en U.S. Geological Survey Saltwater intrusion in the Floridan aquifer, coastal Citrus and Hernando Counties, Florida, 1975 reports