The purpose of this specification is to provide standards and methods to measure and demonstrate that the actual PSD of any given material is within an acceptable error range of the target PSD that has been established through a testing protocol.
Agencies which regulate the use of stormwater treatment technologies frequently require laboratory testing of the devices, utilizing silica based surrogate sediment. The objective of these studies is to test the sediment removal rate as a function of flow, particle size removal , particle resuspension and washout. In some agencies a standard manufactured silica sediment product is specified whereas in other agencies a custom particle size distribution(PSD) is specified and the testing organization is tasked with mixing commercially available materials to approximate the specified PSD. Recently several manufactured silica sediment products, which have served as the standard contaminants specified by many agencies, have been discontinued. This change has occurred faster than regulatory agencies have been able to address the void. Subsequently, laboratories have been relying on rapidly diminishing stockpiles or attempting to recreate the products through sieving other products. In addition, prior research has shown that these standardized materials can have a significant variance in the PSD from published data. Manufactured for the purpose of foundry casting sand, the preciseness of the specification relative to the needed precision for testing in stormwater devices does not have a range of acceptable error. Since the use of these materials is for technology verification and these verifications are being conducted by different individuals, in different laboratories, utilizing different lots or admixtures, standards are needed to ensure that devices are tested using material within the specification such that there is a level of confidence the same materials are being used.
KeywordsParticle Size Distribution Hydrodynamic Seperators, Stormwater Filters
The title and scope are in draft form and are under development within this ASTM Committee.Back to Top
Draft Under Development