Section Twelve
TOXIC AND HAZARDOUS WASTES
36    REGULATION OF TOXIC ORGANICS IN INDUSTRIAL
SEWER DISCHARGES AT THE SANITATION
DISTRICTS OF LOS ANGELES COUNTY
Jay G. Kremer, Head
M. Philip Lo, Senior Engineer
Paul C. Martyn, Supervising Civil Engineer
Leon S. Directo, Supervising Civil Engineer
Industrial Waste Section
Sanitation Districts of Los Angeles County
Whittier, California 90607
REGULATORY TRENDS FOR TRADITIONAL AND TOXIC ORGANIC POLLUTANTS
Traditional Pollutants
For many years prior to about 1980, the traditional pollutants regulated by wastewater agencies
included mainly heavy metals, pH, cyanide and miscellaneous pollutants such as sulfides. Various
materials which cause physical sewer clogging problems such as oil and grease, paunch manure from
slaughterhouses, feathers from poultry processors, etc. were also regulated. Heavy metals were regulated due to the acute toxicity problems found when discharged in excess to biological treatment
plants. The effluent limits established were aimed at preventing treatment plant upsets as well as
insuring proper treatment plant effluent quality. The heavy metal limits most strongly affected
companies in the metal finishing and allied industries.
Prior to 1972, the Sanitation Districts of Los Angeles County did not extensively regulate industrial
companies except for major pollutant problems. This was partly due to the absence of any significant
level of biological treatment capacity. Primary treatment was provided at the Sanitation Districts'
large Joint Water Pollution Control Plant (JWPCP) prior to ocean discharge. In the early 1970s, due
to State and Federal laws, the Sanitation Districts established industrial effluent limits as shown in
Table I. These limits were set to meet California ocean discharge requirements for the JWPCP. The
limits were intended to be a first step (Phase I) and were to be made more stringent as needed to meet
JWPCP effluent quality requirements. DDT, PCBs and pesticide limits were set due to a major DDT
pollution problem in the Sanitation Districts' area.
The State of California limits for ocean discharges and the resulting Phase 1 industrial discharge
limits within the Sanitation Districts were based on maintaining satisfactory ocean water quality. The
Districts' Phase I effluent limits were found to readily allow compliance with the State's ocean
discharge requirements. Figures 1 through 8 show the decrease in several heavy metals in the influent
to the JWPCP in the years from 1975 to 1986. Figures 1 through 8 present influent heavy metal
quantities in mass terms of total pounds influent to the JWPCP per day. The influent flow to the
JWPCP has also increased slightly from 341 MGD in 1975 to 364 MGD in 1986.
With the implementation of the EPA industrial categorical pretreatment regulations, industrial
effluent limits were established on a different philosophical basis. Effluent limits for industrial
categories were determined by the treatment technology available to produce the highest quality
wastewater effluent. The numerical values set on this basis were in general more severe for the
traditional pollutants than established by water quality conditions at the Sanitation Districts. Table II
shows comparable heavy metal limits under the EPA metal finishing regulations. Such technology
limits did not bear a direct relation to ocean or stream water quality downstream from Districts'
treatment plants.
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