Glossary and Lab Abbreviations

Analyst: A person responsible for testing, quality control, and reporting of analytical results.

Data Quality Objectives: qualitative and quantitative specificiations used to design a study that will limit uncertainty to an acceptable level.

Discipline: Areas of certification for the testing of drinking water, i.e., microbiology, radiochemistry, inorganic chemistry, and organic chemistry.

Holding Time: The allowed time from when a sample was taken (or extracted) until it must be analyzed.

LIMS: Laboratory Information Management System.

Maximum Contaminant Level (MCL): The maximum permissible level of a contaminant in water that is delivered to any user of a public water system.

Proficiency Test (or Testing) (PT): Sample(s) provided to demonstrate that a laboratory can successfully analyze the sample(s) within the acceptance limits specified in the regulations. The qualitative or quantitative composition of the reference material is unknown to the laboratory at the time of the analysis.

Public Water System (PWS): A system for the provision to the public of water for human consumption through pipes or other constructed conveyances, if such system has at least fifteen (15) service connections, regardless of the number of water sources or configuration of the distribution system, or regularly serves an average of at least twenty-five (25) individuals daily at least sixty (60) days out of the year.

Quality Assurance (QA): An integrated system of management activities that involves planning, quality control, quality assessment, reporting, and quality improvement to ensure a product or service meets defined standards of quality with a stated level of confidence.

Quality Assurance Manual (QA Manual): A comprehensive plan detailing the aspects of quality assurance required to adequately fulfill the needs of a program. This document is required before a laboratory can be certified or reciprocity is granted.  Also referred to as the QA Plan.

Quality Control (QC): The overall system of technical activities whose purpose is to measure and control the quality of a product or service so that it meets the needs of the users. QC also includes operational techniques and activities that are used to fulfill the requirement of quality.

Standard Operating Procedure (SOP): A written document that describes the method of an operation, analysis, or action whose techniques and procedures are thoroughly prescribed and that is officially approved as the method for performing a routine or repetitive test.

Standard Methods (SM): SM refers to a standard method of water testing published in the Standard Methods for the Examination of Water and Wastewater, a reference source for analytical methods.

Unregulated Contaminants: Contaminants for which monitoring is required but which have no MCL.


Lab Abbreviations


ppm – Parts per million

ppb – Parts per billion

mg/kg – Milligrams per Kilogram (equal to ppm)

mg/L – Milligrams per Liter (equal to ppm)

ug/L – Micrograms per liter (equal to ppb)



COC – Chain of Custody

CFU – Colony forming unit

CWA – Clean Water Act

DMRQA – Discharge Monitoring Report – Quality Assurance

FIA – Flow injection analysis

GC – Gas chromatography

GC/MS – Gas chromatography/mass spectrometry

HAA5 – Haloacetic acids

HPLC – High pressure liquid chromatography

IC – Ion chromatography

ICP – Inductively coupled plasma

ICP-MS – Inductively coupled plasma – mass spectrometry

IDC – Initial Demonstration of Capability

LCS – Laboratory control sample

LRL – Lab reporting limit

MCL – Maximum contaminant level – the highest allowable level of a contaminant in drinking water (established by the EPA)

MDL – Method detection limit – minimum concentration of a substance that can be measured and reported with 99% confidence that the concentration is greater than zero.

MPN – Most probable number

MRL – Method (or minimum) reporting limit

MS/MSD – Matrix spike/matrix spike duplicate

ND – Not detected (concentration is less than the MRL or LRL)

NPDES – National Pollutant Discharge Elimination System

PE – Performance evaluation sample

PT – Proficiency testing sample

PQL – Practical quantitation limit

QA – Quality assurance

QC – Quality control

QCS – Quality control sample

RCRA – Resource Conservation and Recovery Act

RPD – Relative percent difference

SDWA – Safe Drinking Water Act

SOC – Semi-volatile organic compounds

SOP – Standard Operating Procedure

SOQ – Statement of qualifications

SRL – State reporting limit

SVOC – Semi-volatile organic compounds

SW-846 – Test Methods for Evaluating Solid Waste, Physical/Chemical Methods

TCLP – Toxicity Characteristic Leaching Procedure

TDS – Total dissolved solids

TOC – Total organic carbon

TPH – Total petroleum hydrocarbons

UCMR – Unregulated Contaminant Monitoring Rule

UST – Underground storage tank

VOC – Volatile organic compounds

WP – Water Pollution

WS – Water Supply