How do sinkholes form? MZ WmlJ
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Rainfall percolating, or seeping, through the soil absorbs "9w}dQ
carbon dioxide and reacts with decaying vegetation, creating l_6e I
a slightly acidic water. That water moves through spaces sMP:sCRC
and cracks underground, slowly dissolving limestone and 8yn4}`Nc@
creating a network of cavities and voids. As the limestone #00D?nC
dissolves, pores and cracks are enlarged and carry even 0 < g{ V
more acidic water. Sinkholes are formed when the land =LOk13l\"
surface above collapses or sinks into the cavities or when I`NUurQTX
surface material is carried downward into the voids. vHS2q
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Drought, along with resulting high groundwater withdrawals, ? z3]
can make conditions favorable for sinkholes to form. Also, ^_sQG
heavy rains after droughts often cause enough pressure !:3^ hb
on the ground to create sinkholes. P7Xg{L&@.
Sinkholes can be triggered by human activities such as: +, z) #
• Overwithdrawal of groundwater >Co)2d]
• Diverting surface water from a large area and $%=G[/i'
concentrating it in a single point " CM ucK
• Artificially creating ponds of surface water /
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• Drilling new water wells c+8V| '4
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In urban or suburban areas, sinkholes are hazardous [_V:)
because they can destroy highways and buildings. \0nl PXk?G
Sinkholes also can cause water quality problems. During ul$,q05nb
a collapse, surface waters may leak into the aquifer, our B_hPcmB
underground source of drinking water.
