C27.70 - Precast Concrete Products for Stormwater Management

SIGNIFICANCE AND USE
5.1 Each element has unique flow patterns and each element has unique hydraulic characteristics (that is, flow and head loss). In addition, each element may exhibit variable hydraulic capacity as the element filters become occluded, the filter media swells or shrinks, and water viscosity (that is, water temperature) changes. In some cases filters experience hysteresis with respect to filling and emptying. The testing procedure in Section 7 will help develop the parameters necessary to determine the hydraulic capacity of an element at one instance in time. The test can be repeated at desired time increments to determine how the hydraulic capacity varies over time.
SCOPE
1.1 This test standard shall be used to determine the hydraulic characteristics of stormwater filtration elements.  
1.2 Elements tested shall be of a size commonly manufactured, not a scale model.  
1.3 The position and orientation of all filter elements during testing shall be identical to the position and orientation used during normal operation.  
1.4 The direction of flow during testing shall be identical to the direction of flow during normal operation.  
1.5 As each stormwater treatment device is unique in design and hydraulic capacity, a sufficient number of accurately measured data points are needed to properly define the hydraulic characteristics of each test element. Therefore, it is imperative that the element setup and subsequent testing methodologies be well defined and executed to assure accurate flow and elevation data.  
1.6 This test determines the hydraulic capacity of stormwater filtration systems. Test results are not an indicator of the filtration performance with respect to the capture of solids or other materials.  
1.7 Units—The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard.  
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 and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
5.1 Each device has unique flow patterns and turbulence characteristics and may exhibit a wide range of efficiencies as discharge, particle-size distribution, particle density, and flow viscosity (that is, water temperature) changes. The testing procedures described in Section 8 provide a method of measuring the removal efficiency of these devices under a given flow condition, flow viscosity (water temperature), and particle-size distribution and density. Therefore, the results of testing represent the flow, viscosity, and particle-size distribution tested.
SCOPE
1.1 This test method concerns measurement of the efficiency of hydrodynamic separators and underground settling devices in removing suspended sediment from simulated stormwater runoff under conditions defined herein. This test method is not intended for use in determining field removal efficiency.  
1.2 Units tested shall be of a size commonly manufactured, not a scale model. This test method is not intended to address product scaling.  
1.3 This test method is not for measuring the removal efficiency of filters or the scouring potential of hydrodynamic separators and underground settling devices.  
1.4 In this test method, only gravity flow operation is addressed—performance of units operating under pressurized conditions is not addressed.  
1.5 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.  
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.

SIGNIFICANCE AND USE
Each device has unique flow patterns and turbulence characteristics. In addition, each device exhibits a wide range of efficiencies as discharge, particle size, particle density, and flow viscosity (that is, water temperature) change. The testing procedure in Section 7 will help develop the parameters necessary to input into a function that describes the performance of a device under a wide range of application conditions.
SCOPE
1.1 This test method concerns measurement of selected hydraulic characteristics of hydrodynamic separators and underground settling devices critical to their function as stormwater treatment devices.
1.2 Units tested shall be of a size commonly manufactured, not a scale model.
1.3 As each stormwater treatment device is unique in design, so are its hydraulic characteristics (flow versus head and loss coefficients). A sufficient number of accurately measured data points are needed to define properly the hydraulic characteristics of each test unit. Therefore, it is imperative that the unit setup and subsequent testing methodologies be well defined and executed to ensure accurate flow and elevation data.
1.4 This test method addresses gravity flow operation only. It does not address performance of units operating under pressurized conditions.
1.5 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
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.