The Environmental Protection Agency conducted a major study of oil production waste treatment systems to determine the current technology, exemplary systems, and effluent limitations. The study consisted of four phases:
terature survey,
data collection,
field verification and
documentation.
Some of the conclusions of the study are:
Physica1/chemica1 "brine treatment systems consisting of chemical addition and dissolved gas flotation are the best demonstrated technology in the Gulf of Mexico and Cook Inlet, Alaska.
Long term average effluent concentrations of oil and grease for exemplary gas flotation systems is 25 mg/1.
Physical/chemical treatment followed by reinjection of produced waters is the best demonstrated technology on the California coast.
The fluid and solid wastes generated by the oil and gas exploration, drilling and production industry have been included among those studied by the Environmental Protection Agency in order to implement sections 304, 306, and 307 of the Federal Water Pollution Control Act of 1972. From such studies effluent guidelines, standards of performance, and pretreatment standards will be formulated so that permits under Section 402, FWPCA 1972, can be issued to the oil and gas extraction industries for appropriate onshore and offshore facilities. Offshore facilities include those on the Outer Continental Shelf.
Specifically, best practicable control technology (BPCT) has been ascertained for production water from offshore facilities; for sanitary wastes from appropriate offshore manned facilities; for deck drainage from both onshore and offshore facilities; and, for drilling muds and drill cuttings for both onshore and offshore operations. Additionally, BPCT has been addressed for fluids emanating from workover and completion operations and for produced sand.
Prior to the permitting authority contained in section 402, FWPCA, 1972, and the guidelines established by EPA, the U.S. Geological Survey had maintained control over these wastes from offshore operations on the Outer Continental Shelf. Waste guidelines established by USGS were not based on required studies of BPCT and did, in certain cases, vary between the Gulf and Pacific Coasts.
Prior to the late fifties, State controls of these wastes in both territorial and inland waters met with varied successes. It is interesting to note that the first enforcement action brought by the Federal government under the Federal Water Pollution Control Act (PL 660, 1956) for pollution of interstate waters was against production water discharges originating in Arkanses and impacting Louisiana streams. (1) Since that time, subsurface injection of production water from inland oil fields seem to be the rule, rather than the exception, in most oil producing States.
Although the major thrust of these EPA studies was aimed at the reduction of pollutants in effluents that is attainable through the application of BPCT, considerable effort was devoted to the degree of pollutant reduction through the application of best available technology (BAT). Existing point sources are expected to attain BAT by July 1, 1983. New source performance standards (NSPS) are based on the application of best available demonstrated technology.
