1.1 This test method covers the testing of hydrodynamic stormwater separators and underground settling devices as it relates to the measurement of the resuspension and washout (scour) of previously captured sediment.

1.2 Units tested shall be of a size commonly manufactured and available for purchase. In order to facilitate testing it is permissible to substitute alternate materials for the housing and structural components of the test units if operational components are at full size, with identical dimensions, configurations and materials specified for commercial use. Scale models are not permissible.

1.3 The test method provides a means of evaluating retention of suspended solids previously captured with a manufactured treatment device (MTD) that is placed as an offline or online treatment device along storm drain pipe lines. It provides criteria in which to evaluate whether the MTD is appropriate for installation in offline or online conditions.

1.4 This test method provides the means for evaluating the scour potential for both offline and online conditions.

1.5 Units—The values stated in inch-pound units are to be regarded as standard, except for methods to establish and report sediment concentration and particle size. It is convention to exclusively describe sediment concentration in mg/L and particle size in mm or μm, both of which are SI units. The SI units given in parentheses are mathematical conversions, which are provided for information purposes only and are not considered standard. Reporting of test results in units other than inch-pound units shall not be regarded as non-conformance with this test method.

1.6 This test method may be subject to specific requirements set by a Quality Assurance Project Plan, a specific verification protocol, or Authority Having Jurisdiction (AHJ). It is advised to review one or all of the above to ensure compliance

1.7 Acceptance of test results attained according to this specification may be subject to specific requirements set by a Quality Assurance Project Plan, a specific verification protocol, or Authority Having Jurisdiction (AHJ). It is advised to review one or all of the above to ensure compliance.

1.8 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.9 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.