1.1 This test method describes procedures for assessing the biodegradation of chemicals in natural surface water samples.

1.2 This test method provides an opportunity to evaluate rates of biodegradation in the presence and absence of natural sediment materials. It also may provide limited information on the abiotic degradation rate, and sorption to sediment and vessel walls.

1.3 This test method allows for the development of a first-order rate constant, based on the disappearance of the test compound with time, and a second-order rate constant, normalized for changes in microbial biomass.

1.4 This test method requires a chemical specific analytical method and the concentrations of test substance employed are dependent on the sensitivity of the analytical method.

1.5 This test method is designed to be applicable to compounds that are not inhibitory to bacteria at the concentrations used in the test method, which do not rapidly volatilize from water, that are soluble at the initial test concentration and that do not degrade rapidly by abiotic processes, such as hydrolysis.

1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.