Alternative to CBOD₅-Based Load Allocation Studies on Low-Dilution-Ratio Streams

Carbonaceous BOD₅ and ammonia effluent limitations for low-dilution-ratio receiving waters are often determined by using wasteload allocation studies. These studies are labor intensive. They require one-third to one-half a work year to complete. Due to bacteria population dynamics, biological-wastewater treatment plants producing a highly nitrified effluent also produce an effluent low in carbonaceous BOD₅. Using the BOD-ammonia relationship, regulators can achieve the same net results as labor-intensive load allocation studies with only 1% or 2% of the labor, if they concentrate on just protecting the receiving water's un-ionized ammonia standard. Four years of monthly effluent reports from 22 nitrifying wastewater treatment facilities were examined. This examination showed that this alternative to time-consuming wasteload allocation studies is practical.