Table shows the specific surface pipe costs, , in 2002 year dollars and SI units. The cost of CO 2 surface piping by EPA (2008; 2010) is 83000 2008$ in -1 mile -1 , which is for "all elements of pipeline costs," therefore we assume it includes indirect cost and contingency. At the Kemper site, Esposito et al. (2019) reports the cost of 5 miles of 8-and 12-inch CO 2 pipeline as 120000 2017$ in -1 mile -1 , including indirect costs but excluding contingency. GEOPHIRES provides a cost of 500 2017$ m -1 , irrespective of diameter and excluding contingency and indirect costs. GETEM and GEOPHIRES provide piping cost for water while EPA (2008; 2010) and Esposito et al. (2019) provide pipe cost for CO₂. No appreciable dependence on fluid type is seen in this analysis. Most sources use a pipe cost that is linearly proportional with pipe diameter. However, GEOPHIRES assumes a constant value for all diameters and GETEM provides a second-order relation for "standard schedule" (i.e. steel) hydrothermal piping as a function of pipe diameter. This relationship is derived from ASPEN simulations of surface piping, valid from 10 cm to 90 cm, and without indirect cost or contingency.