D.C. Mun. Regs. tit. 21, r. 21-1999
When used in this chapter, the following words and phrases shall have the meanings ascribed:
Accuracy - the measure of bias or consistent departure from the known true value and is determined by using standards and duplicates.
Act - the District of Columbia Water Pollution Control Act of 1984.
Ambient - those conditions which would be normally expected to prevail in the waters of the District, including any legally permitted point and nonpoint source discharges of pollutants; or, in reference to a particular source of pollution, means those conditions which would be expected to prevail without the source of pollution such as in a free flowing, nontidal stream those conditions upstream of the particular source of pollution.
Director - the Director of the Department of Consumer and Regulatory Affairs or his or her representative.
Duplicate - the repeated analysis of split portions of the same sample.
Field measurement - those physical, chemical, radiological and biological properties of samples which are measured in the field at the site of sample collection.
Laboratory measurement - those physical, chemical, radiological and biological properties of a sample which are determined in a laboratory.
Monitoring - the preparation of equipment, the collection of samples, the field and laboratory measurements, the preservation and preparation of the sample and the reporting and storage of the data collected.
Precision - the measurement of closeness with which repeated analysis of a parameter agree and is determined from duplicate samples.
Replicate - those determinations on samples from the same source environment.
Sample - a discrete quantity of water, sediment, biota or other matter which is representative of the source or place from which it was taken.
Spike - the addition of a known amount of a substance to sample matrix containing a measured background concentration of the substance and is useful for determining precision and accuracy.
Standard - a prepared sample matrix containing a known amount of a substance and is useful for calibration and accuracy determinations.
D.C. Mun. Regs. tit. 21, r. 21-1999