Full Scale Laboratory Evaluation of Stormceptor Model Stc 450 for Removal of Tss

Considerable effort is being expended to assess the effectiveness of urban Best Management Practices (BMP) for stormwater quality enhancement. The effectiveness of structural BMP’s is typically evaluated based on a limited amount of test data, which has lead some state organizations established programs requiring mandatory testing for these devices. One such program is the Technology Acceptance and Reciprocity Partnership (TARP), which is a group of state environment agencies including New Jersey, California, Illinois, Massachusetts, New York, Pennsylvania and Virginia. The group has formally agreed to a common strategy of evaluating, approving or permitting environmental technologies. To facilitate the implementation, they have created a third party technical group called the New Jersey Corporation for Advanced Technology (NJCAT) to evaluate manufacturer performance claims. The program has two levels, Tier 1 which is an interim approval given with the understanding that a full scale field test (Tier 2) will be conducted in the State of New Jersey. This paper was prepared for evaluation of total suspended solids (TSS) removal efficiency for a Stormceptor Model STC 900 in accordance with the NJDEP particle size distribution prescribed in their revised laboratory protocol titled “Total Suspended Solids Laboratory Testing Procedure”, dated December 23, 2003 for approval in Tier 1 of the TARP program. Full scale laboratory testing was performed on a Stormceptor Model STC 900. The first objective of the testing was to determine the percent TSS removal at various operating rates (i.e. 25%, 50%, 75%, 100%, and 125%) and the overall annual TSS removal once the NJDEP weight factors were applied. TSS tests were performed with an initial sediment loading of 50% of the sediment capacity in the lower chamber. The second objective was to determine if scouring occurs at 125% of the operating rate when the lower chamber is filled to 50% and 100% of the sediment capacity.