D. – Decision: An opinion or judgment of the PUC that decides the resolution of a proceeding, usually written in the format D.01-02-003. A proposed decision is usually written by a PUC Administrative Law Judge (ALJ), it is then reviewed and voted upon by the Commissioners.

DA – Dedicated Access Line: A special access line going from a caller's own equipment directly to a long distance company's switch.

DASR – Direct Access Service Request: Reports that were filed by the utilities when deregulation was in effect that detailed the number of consumers who were requesting to change energy providers.

Day-Ahead Market: The forward market for energy and ancillary services to be supplied during the settlement period of a particular trading day that is conducted by the Independent System Operator, the now defunct Power Exchange, and other Scheduling Coordinators. This market closes with the Independent System Operator’s acceptance of the final day-ahead schedule.

Day-Ahead Schedule: A schedule prepared by a Scheduling Coordinator or the Independent System Operator before the beginning of a trading day. This schedule indicates the levels of generation and demand scheduled for each settlement period that trading day.

DA - Direct Access: The ability of a retail customer to purchase commodity electricity directly from the wholesale market rather than through a local distribution utility.

dB – Decibel: A unit measurement represented as a ratio of two voltages, currents or powers. It is used to measure transmission loss or gain.

DC – Direct Current: Electric current that flows in a single direction and at a constant voltage.

DC – Dry Current: A circuit that transmits voice signals and carries no direct current.

DCISC – Diablo Canyon Independent Safety Committee: Reviews the operations of Pacific Gas and Electric Company’s (PG&E) Diablo Canyon (Nuclear) Power Plant in order to assess the safety of operations and to make recommendations for safe operation of the plant. The DCISC is required to submit an annual report of its observations and recommendations, first to PG&E, and then to the Governor, the PUC, the California Energy Commission (CEC) and the California Attorney General, along with PG&E’s response to those observations and recommendations.

DCPP – Diablo Canyon Power Plant: Pacific Gas and Electric Company’s two 1,100 megawatt nuclear units located in San Luis Obispo County.

DD – Delay Dial: A dialing configuration whereby local dial equipment will wait until it receives the entire telephone number before transmitting the call.

DD – Draft Decision: Usually written by a PUC Administrative Law Judge (ALJ) at the conclusion of a proceeding and voted on by the Commissioners at a PUC meeting.

DDD – Direct Distance Dialing: A basic toll service that permits customers to dial their own long distance call without the aid of an operator.

DDTP – Deaf and Disabled Telecommunications Program: A California state mandated program under the governance of the PUC. On the Internet at http://www.ddtp.org/.

DDTPAC – Deaf and Disabled Telecommunications Program Administrative Committee: Advises and leads the Deaf and Disabled Telecommunications Program.

Deaf Trust: A program supervised by the PUC to assure telephone service to deaf and disabled persons. Committees made up of utility representatives and consumer groups oversee equipment, service, and safety standards as well as recommend policy to the PUC.

DEC – Direct Embedded Cost: The total current cost of owning, operating and maintaining a utility’s existing system. Under an embedded cost structure, a substantial portion reflects historical capital investments, including depreciation and return on investment.

Decommissioning: The process of dismantling nuclear power plants after they have stopped producing power, including disposal of radioactive waste materials, the destruction or resale of plant equipment, and the return of the power plant site to its original state.

Defendant: The entity, usually a utility, charged in a complaint proceeding with violating a law, order, tariff, or rule of the PUC.

Deferred Fuel Costs: Those fuel costs incurred in one accounting period which are not reflected in billings to customers until a later billing period.

Deferred Income Tax: The tax effect of the timing difference between straight-line depreciation used for its financial reporting purposes and accelerated depreciation used for income tax purposes.

DEIR - Draft Environmental Impact Report: Either created by the PUC, or a contractor hired by the PUC, to discuss the environmental effects of a project. The DEIR is usually issued for comment and then the Final Environmental Impact Report (FEIR) is issued. Usually done to comply with the California Environmental Quality Act (CEQA).

Delta Inflow: The total stream flow entering the Delta from the Sacramento and San Joaquin Rivers , Yolo Bypass, and eastside streams.

Demand: The rate at which energy is delivered to loads and scheduling points by generation, transmission, and distribution facilities.

Depreciation: A means of accounting for the wearing out or gradual obsolescence of a utility plant’s equipment and buildings. As this occurs, an allowance for depreciation expense is made by the PUC that a carrier can charge for transporting materials and are published in minimum rate tariffs (MRTs). It is unlawful to charge below these rates, unless the Commission approves a deviation.

Deregulation: The elimination or reduction of governmental controls on pricing, service, entry, or safety of a utility or group of utilities.

Descrambler: An electronic circuit that restores a scrambled video signal to its standard form.

Desalination: The process of removing salt from the water.

Deviation: The authority formally granted by the Commission for a utility to depart from established rates or standards of service.

DG - Distributed Generation: Also called Self-Generation, whereby consumers use small-scale power generation technologies (typically in the range of 3 to 10,000 kW) located close to where electricity is used (e.g., a home or business) to provide an alternative to or an enhancement of the traditional electric power system.

DID – Direct Inward Dialing: A PBX or CENTREX feature that allows a customer outside the system to directly dial a station within the system.

Disinfectant Byproducts: Compounds formed by combining treatment chemicals with organic materials in the water.

Disk Drive: The electromechanical device that moves the disk or diskette to read from or write to it.

Distribution: The delivery of electricity to retail customers (including homes, businesses, etc.).

Distribution Systems: The portion of an electric system that is dedicated to delivering electric energy to an end user. Or, a water delivery system composed of water main lines, valves and storage reservoirs.

Divestiture: The stripping off of one utility function from the others by selling (spinning-off) or in some other way changing the ownership of the assets related to that function. Stripping off is most commonly associated with spinning-off generation assets so they are no longer owned by the shareholders that own the transmission and distribution assets.

DLEC – Data Local Exchange Carrier: DLECs deliver high-speed access to the Internet, not voice.

Docket Number: A number assigned to a proceeding opened by the issuance of either a Notice of Proposed Rulemaking or a Notice of Inquiry by the PUC. Typically written as D.01-02-003, or R.01-02-003, etc.

DOD – Direct Outward Dialing: A PBX or CENTREX feature that allows a station user to gain direct access to an exchange network.

DOE – Department of Energy: A cabinet-level, executive department of the federal government responsible for a variety of regulatory, research, and marketing programs related to energy production and use.

DOF – Division of Forestry and Fire Protection are dedicated to the fire protection and stewardship of over 31 million acres of California ’s privately owned wildlands. In addition, the Department provides varied emergency services in 36 of the State’s 58 counties via contracts with local governments.

DOF – Department of Finance: California ’s Department of Finance serves as the Governor’s chief fiscal policy advisor, promotes responsible resource allocation through the state’s annual financial plan, and ensures the financial integrity of the state.

DOJ – Department of Justice: The California Attorney General carries out responsibilities of the office through the California Department of Justice.

DOS – Disk Operating System: The system software that manages the flow of information in a computer; the traffic cop.

Downgradient: The direction water flows by force of gravity.

Downstream: Data flowing from the Internet to a computer.

DP – Dialing Plan: A description of the dialing arrangements for customer use on a network.

DS – Data Set: A device that converts data into signals suitable for transmission over communications lines.

DSL – Digital Subscriber Line: Provides digital connection over the copper wire of the local telephone network. DSL allows the phone line to provide digital communication without blocking access to voice service.

DSM – Demand-Side Management: A three-pronged program carried out by gas and electric utilities that is designed to alter customer use of energy in order to improve the efficiency of the utility system, including conservation, load management, and fuel substitution.

DSP – Division of Strategic Planning: A Division of the PUC that discovers, identifies, and addresses issues regarding notable industry concerns and developments, internal and external PUC procedures, and interagency relationships.

DT – Data Terminal: Equipment capable of sending and/or receiving data signals.

DT – Dial Tone: A tone indicating that a carrier’s automatic switching equipment is ready to place a call.

Dth – Decatherm (equals one MMBtu): The approximate heat content of 1,000 cubic feet of gas; 10 therms.

DTMF – Dual Tone Multi-Frequency: Also known as Touch-Tone. A type of signaling that emits two distinct frequencies for each dialed digit.

DWR – ( California ) Department of Water Resources: Operates and maintains the State Water Project, including the California Aqueduct. Also provides dam safety and flood control services, assists local water districts in water management and conservation, promotes recreational opportunities, and plans for future statewide water needs.