R&D Research and development

RA reasonable alternative; regulatory alternatives; regulatory analysis; remedial action; resource allocation; risk analysis; risk assessment

RAC Response action coordinator

RACES Radio Amateur Civil Emergency Service

RACM Reasonably available control measures

RACT Reasonably available control technology

RAD Radiation absorbed dose

RADAR Radio detection and ranging

RB Request for bid

RCDO Regional case development officer

RCE Rotating cylinder electrode

RCO Regional compliance officer

RCP Research Centers Program

RCRA Resource Conservation and Recovery Act

RD Regional director

RD&D Research development and demonstration

RDDT&E Research, development, demonstration, testing and evaluation

RDE Rotating disk electrode

RDV Reference dose values

RE Reasonable efforts; reportable event

REACT Radio emergency associated communication team

REL Recommended Exposure Limit

RF Response factor

RFA Regulatory Flexibility Act

RFB Request for bid

RFD Referenced dose values

RFP Reasonable further programs; request for proposal

RI Remedial investigation

RIA Regulatory impact analysis; regulatory impact assessment

RI/FS Remedial investigation/feasibility study

RILS Regulatory interpretation letters

RITZ Regulatory and investigative treatment zone model

RMCL Recommended maximum contaminant level (being discontinued in favor of MCLG)

RMSE Root mean square error

RO Reverse osmosis

ROC Regional operations center

ROD Record of decision

RODS Records of decision system

ROPA Record of procurement action

RP Responsible party

RQCAR Reportable quantities for carcinogens in hazardous waste

RQTOX Reportable quantities for chronically toxic hazardous substances

RR Response and Recovery Directorate, FEMA; railroad

RRC Regional response center

RREL Risk Reduction Engineering Laboratory

RRT Regional response team

RSD Risk-specific dose

RTECS Registry of Toxic Effects of Chemical Substances

RUP Restricted use pesticide

RWQM Residential Water Quality Monitoring [Program]

S&A Sampling and analysis; surveillance and analysis

SAB Science Advisory Board

SAE Society of Automotive Engineers

SAR Start action request; structural activity relationship; safety analysis report

SARA Superfund Amendments and Reauthorization Act of 1986

SAV Submerged aquatic vegetation

S/C Sand:cement ratio

SC Sierra Club

SCADA Supervisory control and data acquisition

SCADS Superfund Chemical Analysis Data System

SCBA Self-contained breathing apparatus

SCD Soil conservation district

SCE Standard calomel electrode

SCFM Standard cubic feet per minute

SCICOLL Scientific Collections Permit Database

SCLDF Sierra Club Legal Defense Fund

SCO State coordinating officer

SCSA Soil Conservation Society of America

SCSP Storm and combined sewer program

SCW Supercritical water oxidation

SD Standard deviation

SDI Selective dissemination of information

SDTS Spatial Data Transfer Standard

SDWA Safe Drinking Water Act

SDWIS Safe Drinking Water Information System

SEA State enforcement agreement; state/EPA agreement

SEDM State/EPA data management

SEM Standard error of the means; scanning electron microscope; scanning electron microscopy

SEP Standard evaluation procedures

SEPWC Senate Environment and Public Works Committee

SERC State Emergency Planning Commission

SF Standard form (federal); Superfund

SFA Spectral flame analyzers

SFDS Sanitary Facility Data System

SGID State Geographic Information Database

SHARP Safety and Health Assessment and Research for Prevention

SHE Standard hydrogen electrode

SHWL Seasonal high water level

SI Système International (International system of units); site inspection; surveillance index; spark ignition; saturation index

SIC Standard industrial classification

SIDS Screening information data set

SIMS Secondary ion-mass spectrometry

SITE Superfund innovative technology evaluation

SITREP Situation report

SLOSH Sea, Lake, and overland surges for hurricanes

SMCL Secondary maximum contaminant level

SMCRA Surface Mining Control and Reclamation Act

SME Subject matter expert

SMF Standardized monitoring framework

SMO Sample Management Office

SNAP Significant Noncompliance Action Program

SNARL Suggested no adverse response level

SNC Significant noncompliers

SNUR Significant New Use Rule

SOC Synthetic organic chemical

SOFIA Southern Forest Inventory and Analysis

SQG Small Quantity generator

SOILVENT Soil venting model

SOP Standard operating procedure

SOW Scope of work

SPS State permit system

SRF State Revolving Fund

SRM Standard reference method

SRP Special review procedure

SRR Second round review; submission review record

SS Settleable solids; suspended solids

SSA Sole source aquifer

SSAC Soil site assimilated capacity

SSEIS Standard support and environmental impact statement

SSMS Spark source mass spectrometry

STEL Short-term exposure limit

STEM Scanning transmission-electron microscope

STN Scientific and Technical Information Network

STORET Storage and Retrieval of Water-Related Data

STP Sewage treatment plant; standard temperature and pressure

SW Surface water

SWAG Simulated waste access to ground water

SWC Settlement with conditions

SWDA Solid Waste Disposal Act

SWCD Soil and water conservation district

SWMM Storm water management model

SWTR Surface Water Treatment Rule