The Working Capital Fund (WCF) was established by Public Law 101-512, November 5, 1990. As codified in 43 U.S.C. 50a, Public Law 103-332, dated September 30, 1994 modified the original language; the law states:

"There is hereby established in the Treasury of the United States a working capital fund to assist in the management of certain support activities of the United States Geological Survey (hereafter referred to as the "Survey"), Department of the Interior. The fund shall be available on or after November 5, 1990, without fiscal year limitation for expenses necessary for furnishing materials, supplies, equipment, work, facilities, and services in support of Survey programs, and, as authorized by law, to agencies of the Federal Government and others. Such expenses may include laboratory modernization and equipment replacement, computer operations, maintenance, and telecommunications development of software; systems support services such as implementation assistance, training, and maintenance; acquisition and replacement of computer, publications, and scientific instrumentation, telecommunications, and related automatic data processing equipment; and, such other activities as may be approved by the Secretary of the Interior."

The WCF is divided into two entities, Capital Investments and Fee-for-Service Operations. The Capital Investments key purpose is to plan for long-term capital investments and accumulate the required funds over several fiscal years. The USGS is authorized to use the WCF to invest funds from appropriations and/or reimbursable agreements, without fiscal year limitations, for materials, supplies, telecommunications and other equipment and facilities' renovations in support of USGS programs and other agencies of the Federal Government. Normal operating expenses may not be funded through the WCF. Investments must occur, at a minimum, in two fiscal years before acquisition can occur, and are expected to be evenly balanced over the time period defined in the Investment Plan. The Capital Investment entity is divided into four investment components;

• Mainframe Computer Investment Component whose major customer is Office of Program Support of USGS.

• Telecommunications Investment Component whose major customer is the Office of Program Support of USGS.

• Equipment Investment Component whose major customers are the Water Resources Division and Geologic Division of USGS.

• Facilities Investment Component whose major customers are Office of Program Support and the Water Resources Division of USGS.

The Fee-for-Service Operations operates in a business like manner, by recovering fees for services performed based on an established fee schedule. Fees are established though a rate-setting process. The Fee-for-Service components operate in compliance with Office of Management and Budget (OMB) Circular A-25, User Charges, and recover the full cost of goods, services, and resources provided to their customers. For each Fee-for-Service component, an annual budget and pricing schedule is required. User charges are reviewed no less than biennially. Presently, there are five Fee-for-Services components:

• Water Resources Division National Water Quality Laboratory whose major customer is the Water Resources Division of USGS.

• Office of Program Support Washington Administrative Service Center whose major customers are the Department of the Interior, House of Representatives, and Drug Enforcement Administration.

• Water Resources Division Hydrologic Instrumentation Facility whose major customer is the Water Resources Division of USGS.

• Geologic Division Publications whose major customer is the Geologic Division of USGS.

• Water Resources Division Eastern Research Laboratories whose major customer is the Water Resources Division OF USGS.

(Major customers are organizations that accounts for more than 15 percent of the fund's revenues.)