Hydrostatic Test General Permit


Facilities or projects that receive coverage under Mississippi’s Hydrostatic Test General Permit may discharge hydrostatic test water from new pipelines, storage tanks, flowlines, etc. or used pipelines, storage tanks, flowlines, etc. that have been used for the transportation or storage of natural gas, crude oil, or liquid or gaseous petroleum hydrocarbons, or other substances which would adequately be detected by the effluent limitations of this permit into State waters.

This permit may also cover storm water discharges associated with pipeline or storage tank construction, including clearing, grading and excavation disturbing one (1) or more acres. Construction activities associated with oil and gas exploration, production, processing and treatment, and transmission facilities that are defined in the following North American Industrial Classification System (2002 NAICS) codes and titles: 211-Oil and Gas Extraction, 213111-Drilling Oil and Gas Wells, 213112-Support Activities for Oil and Gas Operations, 48611-Pipeline Transportation of Crude Oil and 48621-Pipeline Transportation of Natural Gas, are generally exempt from the construction requirements of this general permit.