IMPLICATIONS OF RECENT USEPA GUIDANCE ON TESTING AND MONITORING OF CLASS VI GEOLOGICAL SEQUESTERING WELLS TO WATER UTILITIES

摘要

Geological sequestering of carbon dioxide in underground geological formations is an emergingrntechnology for mitigating greenhouse gas (GHG) emissions to reduce the potential impacts of climaternchange. The USEPA promulgated regulations for geological sequestering injection wells as a new ClassrnVI injection well classification under the Safe Drinking Water Act in December 2010. The Class VI Rulernrequires owners or operators of these wells to perform several types of activities during the lifetime of thernproject, which can extend over several decades, in order to ensure that the injection well maintains itsrnmechanical integrity, that fluid migration and the extent of pressure elevation are within the limitsrndescribed in the permit application, and that underground sources of drinking water (USDWs) are notrnendangered. These monitoring activities include mechanical integrity tests (MITs), injection well testingrnduring operation, monitoring of groundwater quality in several zones, tracking of the carbon dioxidernplume and associated pressure front, and, at the discretion of the UIC Program Director, soil gas andrnsurface air monitoring. This paper presents an evaluation of the draft Class VI CO_2 Injection Well Testingrnand Monitoring Guidance document performed for the American Water Works Association (AWWA) tornaddress the concerns of drinking water utilities that could potentially be impacted by geologicalrnsequestering projects.