Pollution Abatement in the Lead Mining District
of Missouri
FRANK RYCK, JR., Fishery Biologist
JAMES R. WHITLEY, Supervisor
Water Quality Investigations Branch
Fisheries Research Section
Missouri Department of Conservation
Columbia, Missouri 65201
INTRODUCTION
The development of a new lead mining area and associated industrial complex in the
southeast Ozarks of Missouri prompted the Missouri Department of Conservation to
monitor and evaluate the water quality of streams in this region. The diversity of the bottom
dwelling invertebrate (benthic macroinvertebrate) community was the parameter used to
measure water quality. This report documents biological conditions in three streams prior
to and after the start of lead mining and milling, and evaluates the effectiveness of mill
effluent recycling and stream channel modification as pollution abatement techniques.
STUDY AREA
The lead mining area in which the study streams are located is shown in Figure 1.
Indian Creek, Bee Fork and Strother Creek, the streams discussed in this report, are typical
Ozark streams. They are normally alkaline, extremely clear, and have steep gradients.
Stream substrate is generally chert fragments that range from gravel to boulder/size.
Vegetation in the study area is primarily the oak-hickory climax association found in Clark
National Forest. Diatoms are the dominant form of aquatic vegetation except in areas of
organic pollution where filamentous algae becomes dominant. Unpolluted streams in this
area possess abundant and diverse communities of both vertebrates and invertebrates (1,2).
METHODS
Invertebrate samples were collected from riffle areas in the study streams with a 20
strand per inch (8 strand per cm) nylon bottom net. In 1964 (3) it was found that it was
necessary to sample about six square feet of riffle bottom to yield a high percentage of the
species present. Six locations totaling between six and ten square feet were sampled at
each station by digging into the substrate immediately upstream from the net to a depth of
4 to 6 inches with a 3-pronged garden tool.
Samples were washed and separated in the field with two screens, '/2-inch mesh
hardware cloth and 1 / 40-inch mesh brass strainer cloth. Material on the coarse screen was
examined, organisms found retained, and debris discarded. Organisms from the coarse
screen and all material from the fine screen were preserved in 10% formalin. In the
laboratory, invertebrates were separated from debris by sugar flotation (4) and
handpicking. Using standard references identification of organisms was as follows: 1)
Flatworms, segmented worms, and roundworms were identified to class; 2) True flies were
identified to family or genus, depending on the organisms; 3) Stoneflies, mayflies, and
caddisflies were identified to species when possible; and 4) Snails, crustaceans, and other
organisms were usually identified to genus.
Stream conditions were evaluated by studying the diversity of the bottom dwelling
invertebrate (benthic macroinvertebrate) community. Since they are relatively immobile
and cannot quickly avoid harmful changes their presence, abundance, or absence reflect the
environmental conditions of the recent past. Since many invertebrates have different
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