The pesticide DDT and the transformer coolant PCB were commonly used up until 1972 when DDT was banned and 1979 when PCB was banned due to the detrimental effect of these two chemicals on the environment. Both of these compounds persisted for a very long time. Recognizing this and the many beneficial uses of the beaches, ports and San Pedro Bay, the California Regional Water Quality Control Board, Los Angeles Region (Regional Board) developed a total maximum daily load (TMDL) to attain the water quality standards. This TMDL became effective on March 23, 2012 and required public agencies to begin monitoring the amount of residual DDT, PCB and related compounds being discharged into the rivers by stormwater and urban runoff.
The Gateway Water Management Authority worked with over 60 individual cities and agencies to forge cooperative agreements to establish three monitoring sites. One site is located along the Los Angeles River as the flow enters the estuary, the second and third sites are located on the San Gabriel River and its major tributary Coyote Creek just upstream of the San Gabriel River estuary.
Beginning in April 2015, an Agreement was made and entered into by and between the GWMA and each participant for administration and monitoring. Annual Reports are being submitted to the Regional Board. Under This agreement, GWMA will invoice and collect funds from the Permittee to cover its portion of the monitoring costs and hire and retain consultants to install monitoring stations and conduct monitoring at the monitoring stations. This Agreement is in effect for a 3 year period and is anticipated to be renewed on a regular basis.