SPRAY IRRIGATION OF CITRUS WASTE
C. W. Sheffield, President
Bio Engineering Sciences, Inc.
Orlando, Florida 32806
Michael D. Sims, Vice President
Jammal & Associates, Inc.
Winter Park, Florida 32790
This chapter reviews the problems associated with spray irrigation of citrus waste. First
we should review the history of the citrus industry and determine the scope of this chapter.
The literature indicates wastes were introduced into the United States in the 1500s.
Records indicate that citrus fruits were shipped from St. Augustine, Florida sometime
in the 1600s. From that time until 1935, shipping consisted only of fresh fruit and posed
little or no waste disposal problem. In 1935 the single-strength juice process was developed, and in the early 1940s came the advent of the hot-pack concentration industry.
Shortly after World War II, the frozen concentrate process was perfected as an economically feasible industry. With this new-found technique, the citrus industry has grown faster
and bigger than anyone had expected. The entire operation of the industry is subjected to
whims of adverse weather conditions as well as numerous diseases which have plagued the
crops. Even with the severe freezes which occurred during the 1957-1958 and 1962-1963
seasons, the number of citrus fuits grown has more than doubled in the last 15 years. It is
interesting to note that citrus fruits are normally grown in the states of Florida, California,
Texas and Arizona in that order of production.
SCOPE
The scope of a chapter of this nature could be rather wide, but the initial problem in
the citrus industry starts in the field. Citrus fruits are grown in warm, subtropical climates
and require an excess of rain, hot temperatures, and are usually grown on sandy soil in
Florida. Citrus trees are grown on many other types of soil in other parts of the world.
The fruit is harvested between October and June of each year, depending upon the type
of citrus. In the hot climates the fruit is very susceptible to spoilage and consequently,
must be processed with the greatest amount of celerity or large losses will occur. To offset
large transportation problems, the processing plants are located within the various citrus
belts. The citrus industry is seasonal and localized to warm climates.
Like other fruit industries, citrus requires a tremendous amount of care when growing
if a profit is to be achieved by the grove owner. From this intense care, serious pollutional
problems have arisen from these groves: the leaching of excess fertilizer to the watercourses.
For this chapter we will limit the scope to effluent disposal methods by spray irrigation
from a concentrating and/or single-strength citrus processing plant.
POLLUTION CONTROL REQUIREMENTS
The Federal Water Pollution Control Act amendments of 1972 (PL 92-500) required
the U.S. Environmental Protection Agency (EPA) to establish guidelines on industrial
waste discharges. These guidelines initially covered fecal coliform, total suspended solids
(TSS), biochemical oxygen demand (BOD), pH and oil and grease (O&G). For the citrus
industry they set for  1977;  1.6 lb/ton raw product BOD and 2.40 lb/ton raw product
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