Hawaii Department of Transportation's Approach in Meeting TMDL: A Comprehensive Implementation Strategy

摘要

Among the many impaired waterbodies on the Island of Oahu that have been listed inthe 303(d) of Clean Water Act, three waterbodies, Kawa Stream, Ala Wai Canal, andWaimanalo Stream have EPA approved Total Maximum Daily Loads (TMDL)established by Hawaii Department of Health (HDOH). Load allocations weredeveloped for all three waterbodies as part of the process. Two watersheds, Kawaand Ala Wai Canal, have waste load allocations (WLA) assigned to several NPDESMS4 permit holders including the Hawaii Department of Transportation, HighwaysDivision (HDOT-Hwys).HDOT-Hwys has developed a comprehensive strategy that includes theimplementation and monitoring plan for the three watersheds. The TMDL/WLAImplementation Plan identifies specific activities where the reduction of total nitrogenand total phosphorus discharges in each watershed are necessary to comply with theWLAs. The monitoring plan specifies the water quality monitoring and trackingactivity necessary to demonstrate efforts to comply with the urban source WLAsassigned to HDOT-Hwys and the effectiveness of the BMPs and the WLAimplementation.