Well design as a factor contributing to loss of water from the Floridan Aquifer, eastern Clay County, Florida

A number of wells penetrating the Floridan aquifer in eastern Clay County were found to be losing water to permeable zones above this aquifer. A differential in artesian pressure was observed in closely spaced wells of similar depth. Further investigation. revealed that the pressure differential in the wells was due to the design of the wells, of which there were four principal types. A comparison of the four types of wells in relation to the subsurface geology showed that three types of wells were open to the permeable zones above the Floridan aquifer. In such wells water of relatively high head from the Floridan aquifer moves up through the well bore and out into zones of relatively low head. The estimated water loss from poorly designed wells ranged from 32 to 180 gpm (gallons per minute). The artesian head loss in leaky wells ranged from 3 to 15 feet. A total loss of water of 39 mgd (million gallons per day) was estimated from all the leaky wells in the area. A significant decline of the piezometric surface of the Floridan aquifer was observed in eastern Clay County. Some of this decline can be attributed to the loss of water from the Floridan aquifer through these poorly designed wells. (Document has 16 pages.

ALMA Observations of the IRDC Clump G34.43+00.24 MM3: DNC/HNC Ratio

We have observed the clump G34.43+00.24 MM3 associated with an infrared dark cloud in DNC $J$=3--2, HN$^{13}$C $J$=3--2, and N$_2$H$^+$ $J$=3--2 with the Atacama Large Millimeter/submillimeter Array (ALMA). The N$_2$H$^+$ emission is found to be relatively weak near the hot core and the outflows, and its distribution is clearly anti-correlated with the CS emission. This result indicates that a young outflow is interacting with cold ambient gas. The HN$^{13}$C emission is compact and mostly emanates from the hot core, whereas the DNC emission is extended around the hot core. Thus, the DNC and HN$^{13}$C emission traces warm regions near the protostar differently. The DNC emission is stronger than the HN$^{13}$C emission toward most parts of this clump. The DNC/HNC abundance ratio averaged within a $15^{\prime\prime} \times 15^{\prime\prime}$ area around the phase center is higher than 0.06. This ratio is much higher than the value obtained by the previous single-dish observations of DNC and HN$^{13}$C $J$=1--0 ($\sim$0.003). It seems likely that the DNC and HNC emission observed with the single-dish telescope traces lower density envelopes, while that observed with ALMA traces higher density and highly deuterated regions. We have compared the observational results with chemical-model results in order to investigate the behavior of DNC and HNC in the dense cores. Taking these results into account, we suggest that the low DNC/HNC ratio in the high-mass sources obtained by the single-dish observations are at least partly due to the low filling factor of the high density regions.Comment: accepted to Ap