Section 250-RICR-150-10-8.31 - Pretreatment - Proprietary DevicesA. Feasibility 1. To qualify as an acceptable pretreatment device, proprietary devices shall remove a minimum of 25% TSS, as verified by an independent third-party monitoring group. In certain retrofit cases and other cases where higher pretreatment standards may be appropriate, higher removal efficiency for TSS may be required in order to achieve stormwater treatment goals for the project.2. Proprietary devices shall be designed per the manufacturer's recommendations.3. Proprietary devices must be designed as off-line systems or have an internal bypass to avoid large flows and resuspension of pollutants in order to be used as pretreatment for other BMPs.B. Design 1. Flow-through proprietary devices shall be designed to treat runoff from the entire WQf. For these devices, a minimum detention time of 60 seconds is required for the WQf.2. A storage proprietary device shall be sized based on the required pretreatment volume (% WQv) or a designer must provide documentation that it is sized appropriately for a verified minimum removal of 25% TSS.3. For proprietary devices such as oil/grit separators, all baffles shall be tightly sealed at sidewalls and at the roof to prevent the escape of oil.C. Maintenance 1. Proprietary devices shall be maintained in accordance with manufacturers' guidelines.2. Proprietary devices shall be located such that it is accessible at times for maintenance and/or emergency removal of oil or chemical spills.3. Inspections shall be performed a minimum of 2 times a year. Devices shall be cleaned when pollutant removal capacity is reduced by 50% or more, or where 50% or more of the pollutant storage capacity is filled or displaced. Hazardous debris removed shall be disposed of in accordance with State and federal regulations by a properly licensed contractor.250 R.I. Code R. 250-RICR-150-10-8.31
Amended effective 11/13/2018