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METHODS OF ANALYSIS FOR WASTE LOAD ALLOCATION
Citation:
Eheart, J. W., J. C. Liebman, AND E. D. Brill Jr. METHODS OF ANALYSIS FOR WASTE LOAD ALLOCATION. U.S. Environmental Protection Agency, Washington, DC, EPA/600/M-89/014, 1990.
Impact/Purpose:
to present information
Description:
This research has addressed several unresolved questions concerning the allocation of allowable waste loads among multiple wastewater dischargers within a water quality limited stream segment. First, the traditional assumptions about critical design conditions for waste load allocation were shown to be true (except for some highly uncommon situations) in multi-discharger settings—namely, that lower streamflows and higher temperatures lead to more stringent allowable loads. Second, a method was developed for aggregating dischargers together into discrete groupings so that the water quality interactions between groups was minimized. This allows waste load allocations to be made separately for each grouping, thereby simplifying the overall computational process. Third, the issue of setting aside unallocated waste load capacity as a reserve against future growth or modeling uncertainty was examined. A case study illustrated the unique relationships that might exist between this reserve capacity, the frequency of water quality excursions, and the cost of wastewater treatment. Finally, a method was developed for designing multi-discharger seasonal waste load allocations. It determines seasonal discharge limits for each discharger that minimizes the degree of treatment necessary to provide the same risk of water quality excursion as would exist under a nonseasonal waste load allocation.