Injection wells make use of deep geological formations to store large quantities of gasses or liquids
underground. Injection wells should isolate their contents from both groundwater sources and other rock
layers. Most of the around 28,000 injection wells related to oil and gas operations (known as “Class II”
wells) are located in Texas, Oklahoma, Kansas, and California. Insuch wells, wastewater is injected well below the water table and/or surficial aquifer. In New York, this will occur only after a permitting process involving the NY DEC and
the Division of Mineral Resources. Because injection wells will not be regulated under the dSGEIS, they
will require site-specific environmental review.