When are Quarterly Estimated Taxes Due? Estimated taxes are due quarterly on specific dates during the year. The IRS mandates that the normal due dates for estimated taxes are April 15 for the first quarter of a year, June 15 for the second quarter, Sept. 15 for the third quarter and Jan.15 of the following year for the fourth quarter.
Salt water intrusion occurs in coastal freshwater aquifers when the different densities of both the saltwater and freshwater allow the ocean water to intrude into the freshwater aquifer.hen this occurs, it will move the saltwater freshwater interface inland, resulting in a higher saline concentration in the aquifers' water, rendering it useless for human consumption, unless it is treated. Figure 4. Saltwater Intrusion Situation(University of Florida, 2000)).
OECD Statistics. French Equivalent: Intrusion d eau sal e Definition: Salt water intrusion is the mixing of saltwater with freshwater. It can occur in either surface-water or groundwater bodies. Source Publication: Glossary of Environment Statistics, Studies in Methods, Series F, No. 67, United Nations, New York, 1997.