Chlorinated Hydrocarbons:   Emerging
Implications In Regional Planning
TIMOTHY G. SHEA, Assistant Manager
WILLIAM E. GATES, Manager
Research and Development Laboratory
Engineering-Science, Inc.
Oakland, California
INTRODUCTION
The San Francisco Bay-Delta System consists of two major estuaries which are
confluent in Central San Francisco Bay and which empty through the Golden Gate
into the Pacific Ocean (Figure 1). The Northern Estuary consists of San Pablo and
Suisun Bays and the Sacramento-San Joaquin River Delta; the Southern Estuary
consists of Southern San Francisco Bay and Lower San Francisco Bay. The major
fresh water inflow to the Bay-Delta is derived from the runoff of the Sacramento and
San Joaquin Rivers which drain the agriculturally-rich Central Valley of California.
Essentially no fresh water inflow to the Southern Estuary occurs in the summer and
fall months other than the treated waste discharges of nearly 3,000,000 people who
reside contiguous to the shores of the Southern Estuary.
The San Francisco Bay-Delta Water Quality Control Program was conducted
during 1966-1968 with the objectives of assessing the magnitude and effects of
wastewater discharges in the 12-county region encompassing San Francisco Bay, and
to develop plans for achieving water quality management on a regional basis through
year 2000. In conjunction with the Bay-Delta Program, a review was made of available information describing the sources and fate of chlorinated hydrocarbons in the
San Francisco Bay hydrographic and lithographic system. It was found that a considerable body of information on chlorinated hydrocarbons in agricultural drainage
from the Central Valley of California had been developed by the Department of
Water Resources, State of California, and by the FWPCA , after 1963, some of
which have been published (1,2). However, no information was available to permit
estimation of the quantities of chlorinated hydrocarbons entering San Francisco Bay
from municipal and industrial sources or of the quantities of chlorinated hydrocarbons from municipal, industrial, and agricultural sources being transported
through or accumulating in San Francisco Bay. Because of the continuing and increasing use of chlorinated hydrocarbons in products for agricultural, domestic, and
industrial uses, and because of the growing concern about these compounds in the
environment, more complete information on the sources and fate of chlorinated
hydrocarbons in the Bay-Delta was required before recommendations for a regional
water quality policy for these compounds could be formulated.
The objectives of this study were: 1) to develop estimates of chlorinated
hydrocarbon emissions in municipal and industrial wastewaters, 2) to update and
expand data on levels of chlorinated hydrocarbons in water and sediments in the
Bay-Delta region, and 3) to formulate a mass balance of pesticide transport into and
from the San Francisco Bay System.
APPROACH TO PROBLEM
Planning for the study began with development of a procedure for estimating
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