An unconfined aquifer is comprised of two main layers: a well-sorted sand from 0 – 50 ft below the ground surface and a well-sorted gravel from 50 – 78 ft below the ground surface. The aquifer is underlain by a clay aquitard. Recently, the Maryland Dept. of Environment discovered that in 1990 illegal, toxic chemicals was put into a disposal well that is 5900 ft upgradient of the water supply wells for a town. Some of the water supply wells are slotted in the sand and some in the gravel layer. Assuming that the toxic chemical travel at the same rate as the groundwater and that water does not move between the sand and gravel layers, calculate the time (in years) that it might take water to flow from the disposal well to the water supply wells. The town will determine if they should start testing the wells for the toxic chemicals based on your calculations. Disposal well Water supply wells
Ground surface elevation (ft) 148 142
Water table depth below ground surface (ft) 31 34

dsxdcfghj

explanation:

a, c, d, e are all applying about success strategies.

bacteria that live on the ocean floor are sustained by phytoplankton. phytoplankton, microscopic marine photosynthetic organisms, have a vastly significant role to play not only in the marine food web of which they’re part of, but also on a more global scale. despite their infinitely small size in comparison to other marine organisms, these tiny creatures occupy an immensely important ecological niche: they are the foundation of the marine food web, and as primary producers, play key roles in supporting all other organisms in the marine environment, as well as in the regulation of the earth’s climate through the sequestration of carbon, oxygen production, and other related processes. phytoplankton account for roughly half of all global primary productivity; therefore, their significance extends far beyond the marine environment alone. there is an intriguing sense of irony in the realization that these tiny living beings that often live out their existence unnoticed and undetected by the rest of the world, have such a far-reaching impact on the lives of virtually all other living organisms on the planet, particularly on those in the marine environment. the world that we have become accustomed to has been and is continuously shaped by the workings of these miniscule yet vital “plants of the sea”.

hope this !