The Environmental Protection Agency is developing a set of regulatory alternatives for the geological sequestration (GS) of carbon dioxide. EPAs rule, which will be part of EPAs Underground Injection Control regulations, will provide federal requirements for owners and operators of sequestration operations. It is intended to protect underground sources of drinking water and provide regulatory certainty and permitting consistency for industry. This Technology and Cost (T&C) Document describes the costs of specific technologies and operating practices that could be applied to underground geologic sequestration of CO2. The costs are estimated for specific technologies, and then are applied to examples of saline reservoirs, depleted gas reservoirs, and depleted oil reservoirs to estimate total project costs. Examples are provided for both commercial scale and pilot scale geologic sequestration projects.