Summary This paper shows, in a systematic way, that the long-term solution to the environmental issue in petroleum engineering is the development of a new area: environmental control technology (ECT). ECT is defined as intrinsic in and integrated with an oilfield process. Its preventive function is contrasted to the remediating nature of conventional waste-management technology (WMT). This paper has two objectives: to identify and qualify ECT for petroleum engineering and to overview recent ECT developments, particularly in oilfield production operations. Introduction In the 1980's, low oil prices forced oilfield technology to focus on economic efficiency and productivity. Simultaneously, environmental regulatory pressure added a new factor to petroleum engineering economics: the cost of working within the constraints of an environmental issue. The industry is absorbing this cost while revising oilfield technology to reduce the environmental impact. The new area, ECT, has the potential to become a widely accepted way for the oil industry to address the environmental issue. The API is currently working on a supporting agenda for reauthorization of the U.S. Clean Water Act. One important issue of the new act introduces the concept of pollution prevention to the permit procedure. In regulatory language, pollution should be prevented through source reduction, which necessitates improvements to oilfield processes to reduce waste generation. API supports the concept but favors the inclusion of other preventive measures in this act, such as recycling, reuse (beneficial use), and treatment (to comply with discharge criteria).These and similar past regulatory actions have altered the industry's approach to the oilfield environmental issue. As a result, the remediation approach represented by WMT is being replaced with a preventive approach (ECT). The heart of ECT is prevention of environmental impact. The other features need further clarification. Identification of ECT A general definition of ECT is presented in the appendix, along with a description of its basic methods. Ref. 1 discusses the position of ECT among other techniques used by the oil industry to tackle the environmental issue. (The nontechnical means are social, legal, commercial, scientific, and logistic.) The technical approach to the environmental issue usually is undertaken after the nontechnical means become redundant or uneconomical.