Source Control Enhancements to Foster Indirect Potable Reuse

摘要

Source control programs have historically been developed to control toxic pollutantsfrom industrial facilities to address issues related to meeting ocean dischargerequirements, preventing harm to physical facilities and the biological treatmentprocesses within treatment plants, minimizing hazards to workers, and protecting aquaticresources in the river or ocean where discharges occur. With increasing water demandsand the need for larger amounts of water recycling, source control programs need to beexpanded to also control pollutants of concern from drinking water perspective in orderto account for the reuse of treated wastewater. Reuse of treated wastewater throughinjection or surface spreading can supplement groundwater supplies and may impact thequality of groundwater used for drinking water. This factor needs to be considered whendetermining the objectives of source control programs and the strategy to achieve thesource control objectives.Source control enhancements need to go beyond the requirements in the Clean Water Actand federal pretreatment program regulations defined in 40 CFR, Part 403, to activelyaddress compounds that pose a risk to drinking water quality in areas where indirectpotable reuse occurs or is planned. The Orange County Sanitation District and OrangeCounty Water District are implementing a 70 million gallon per day indirect potablereuse project. As part of this project, we are evaluating enhanced source controlactivities, including:1. Developing a list of target compounds of concern based on drinking waterregulations2. Assessing the fate of the target compounds through the treatment system.3. Focused monitoring based on the list of target compounds and their potentialability to persist through the treatment system.4. Characterizing wastewater streams to identify the sources and levels of pollutantsof concerns in an effort to minimize these pollutants.5. Increased outreach to dischargers to manage discharge of compounds of concernat the source.6. Maintaining an inventory of compounds discharged into the wastewater collectionsystem so that new compounds of concern can be evaluated rapidly.