EPA-680/4-75-004
Environmental Monitoring Series
NONPOINT-SOURCE POLLUTION IN SURFACE WATERS:
Associated Problems and Investigative Techniques
National Environmental Research Center
Office of Research and Development
U.S. Environmental Protection Agency
Las Vegas, Nevada 89114
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Develop-
ment, U. S. Environmental Protection Agency, have been
grouped into five series. These five broad categories
were established to facilitate further development and
application of environmental technology. Elimination of
traditional grouping was consciously planned to foster
technology transfer and a maximum interface in related
fields. The five series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
This report has been assigned to the ENVIRONMENTAL MONI-
TORING series. This series describes research conducted
to develop new or improved methods and instrumentation
for the identification and quantification of environ-
mental pollutants at the lowest conceivable significant
concentrations. It also includes studies to determine
the ambient concentrations of pollutants in the environ-
ment and/or the variance of pollutants as a function of
time or meteorological factors.
EPA REVIEW NOTICE
This report has been reviewed by the Environmental Moni-
toring and Support Laboratory-Las Vegas, EPA, and approved
for publication. Approval does not signify that the con-
tents necessarily reflect the views and policies of the U.S.
Environmental Protection Agency, nor does mention of
trade names or commercial products constitute endorse-
ment or recommendation of use.
Document is available to the public for sale through
the National Technical Information Service, Springfield,
Virginia 22161.
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EPA-680/4-75-004
June 1975
NONPOINT-SOURCE POLLUTION IN SURFACE WATERS:
Associated Problems and Investigative Techniques
by
Water and Land Monitoring Branch
Monitoring Applications Laboratory
National Environmental Research Center
Las Vegas, Nevada
ROAP 22AEB
Program Element No. 1HA326
Task Completion Report
NATIONAL ENVIRONMENTAL RESEARCH CENTER
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
LAS VEGAS, NEVADA 89114
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ABSTRACT
Contaminants entering waterways from diffuse or non-distinct
points are termed nonpolnt-source pollutants. Principal categories
of nonpoint-source pollutants In surface waters include sediments,
minerals and adds, pesticides, nutrients, organic matter, heat,
microorganisms and radioactive materials. Nonpolnt-source pollu-
tants are generated primarily by such activities as agriculture,
silviculture, mining, construction and hydrographic modifications.
In terms of volume alone, sediment 1s the pollutant of greatest
significance, and agricultural cropland 1s the chief contributor.
Various models are available for predicting rates and effects of
nonpoint pollutants 1n surface water. Capabilities for predicting
sedimentation rates, thermal pollution and mine drainage are fairly
sophisticated, but methods for predicting pollution resulting from
pesticides, nutrients, heavy metals, biological contaminants and
organic wastes are not well refined. Techniques for monitoring
nonpolnt-source pollutants Include manual field sample collection,
automated samplers, automatic contact sensors, and to an extent,
remote sensing devices. Parameters which can be automatically
monitored in situ with contact sensors Include turbidity, tempera-
ture, certain specific Ions, specific conductance, pH and dissolved
oxygen. Most other parameters must be measured using laboratory
analytical procedures. Aerial reconnaissance can be used In a cost-
effective manner to assess the Impact of agriculture, construction,
mining and silviculture activity on waterways, but quantitative
water quality data cannot be reliably produced with remote sensing
techniques.
111
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TABLE OF CONTENTS
Page
SUMMARY 1
INTRODUCTION • 3
NATURE AND ORIGIN OF NONPOINT-SOURCE POLLUTION ' 5
CATEGORIES OF NONPOINT-SOURCE POLLUTANTS , 5
Sediments 5
Minerals and Adds 5
Pesticides 6
i
Nutrients 6
Organic Substances 6
Heat 6
Microorganisms 7
Radioactive Materials 7
SOURCES OF NONPOINT POLLUTANTS 7
Agriculture 7
Si 1 vi cul ture 10
Mining 11
Construction 12
i
Hydrographic Modification 12
1v
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Page
PREDICTION OF NONPOINT-SOURCE POLLUTION 17
AGRICULTURE 17
20
SILVICULTURE
ACID MINE DRAINAGE 21
IMPOUNDMENTS 21
DREDGING 21
NONPOINT-SOURCE MONITORING 23
NONPOINT-SOURCE MONITORING STRATEGY 23
PRIMARY MONITORING PROGRAM 23
WATER DATA ACQUISITION 24
Field Measurements with Contact Sensors 26
Field Sample Collection 30
Laboratory Analytical Procedures 34
Remote Sensing 34
REFERENCES -• 35
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TABLES
No,.
1 Summary of Sediment Prediction Methods .^ ..... ,18
25
2 Parameter Matrix .............................
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SUMMARY
Nonpolnt-source pollutants are those water-degrading substances
which enter waterways from diffuse or non-distinct points in such a
manner that treatment at the source is impossible or impractical.
The major categories of nonpoint-source pollutants include sediments,
minerals and acids, pesticides, nutrients, organic matter, heat, micro-
organisms and radioactive wastes. Nonpolnt-source pollutants are
generated primarily by such activities as agriculture, silviculture,
mining, construction and hydrographic modification. Each of these
activities releases numerous water-degrading substances to surface
water, but in terms of volume alone, sediment is the pollutant of
greatest significance, and agricultural cropland is the chief con-
tributor.
Various models for predicting input and output of pollutants
are available for use by planners and engineers in designing
control and monitoring programs for nonpolnt pollutants. These
predictive tools vary tremendously in levels of sophistication and
utility. Methods for predicting sedimentation rates, thermal pol-
lution and mine drainage are fairly well developed, while predic-
tive capabilities for pesticides, nutrients, heavy metals,
biological pollutants and organic wastes are not well refined.
Water monitoring programs to be instituted by the States are
required by Federal legislation to assess trends in water quality,
to evaluate the effectiveness of pollution control and abatement
actions and to determine the need for reduction of such programs.
Automated monitoring of certain critical parameters is possible
with contact sensors. The state-of-the-art of automated sampling
and continuous data recording permits the development of a monitoring
system for selected parameters that will maintain its calibration,
accuracy and reproduc1b1lity for approximately 1 month unattended.
The system can also be designed to permit the telemetering of data
to a central point at predetermined finite intervals. Parameters
which can be monitored automatically with a minimum of maintenance
include turbidity, temperature, certain specific ions, specific
conductance, pH, and dissolved oxygen. Sensors are being developed
to detect oil and grease in water, but identification and quantifi-
cation of these substances require laboratory analyses.
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Manual field sampling and/or automatic composite sampling are
required to provide samples for analysis of numerous parameters
which are not easily measured 1n situ with contact sensors. In-
cluded in this category of parameters which are usually measured in
the laboratory are nutrients, pesticides, heavy metals, many specific
ions, suspended and dissolved solids, acidity, alkalinity, chemical
oxygen demand and total organic carbon.
Aerial reconnaissance can be used in a cost-effective manner
to assess the impact of agriculture, construction, mining and silvi-
culture operations on waterways. Aerial photography is useful to
aid 1n determining whether control measures have been implemented
within a given study basin. Remote sensors are currently being
developed which may provide Information on relative sediment and
salinity concentrations 1n a given waterway, thus focusing attention
upon potential problem areas.
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INTRODUCTION
Historically, the major efforts in this country to combat water
pollution have been directed toward the control and abatement of
polluting substances originating from discrete point sources such
as municipal sewage treatment plant effluents and industrial waste
discharges. Recently, the need for programs to control pollutants
arising from diffuse or nonpoint sources has been emphasized in an
attempt to meet the objectives of the Federal Water Pollution Control
Act Amendments of 1972 (PL 92-500), which call for the complete
elimination of pollution discharges to the Nation's waters by 1985.
The need for an assessment of nonpoint pollution sources and
measures for the control of such pollutants is recognized in
Section 204(e), PL 92-500, which requires the Administrator of the
U.S. Environmental Protection Agency (EPA) to issue information
including: (1) guidelines for identifying and evaluating the nature
and extent of nonpoint sources of pollutants, and (2) processes,
procedures, and methods to control pollution resulting from (a) agri-
cultural and silvicultural activities, (b) mining activities,
(c) construction, (d) subsurface disposal of pollutants, (e) salt
water intrusion, and (f) hydrographlc modification. Pursuant to
this legislative mandate, EPA's Office of Air and Water Programs
Issued several reports addressing each of these nonpoint-source
pollution categories. For an in-depth treatment of problems associ-
ated with each category and possible control measures, the reader
is referred to the appropriate report in the series cited in the
References section of this report (EPA, 1973 a-h).
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The current national goal of zero discharge by 1985, Including
abatement of nonpolnt pollution, has placed an urgent demand on
technological capabilities for assessing progress toward this goal.
This necessitates the Implementation of effective monitoring pro-
grams, the refinement of techniques and the development and utili-
zation of sophisticated sensing Instruments, Including remote
sensors, whenever possible. It Is the Intent of this report to
present a synopsis of the major categories and sources of nonpolnt
pollution affecting the Nation's surface waters, the effects of such
pollution, and state-of-the-art Information on existing capabilities
for predicting, detecting and measuring such pollutants 1n surface
waters. No attempt is made to address groundwater pollution problems,
control measures or monitoring techniques.
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NATURE AND ORIGIN OF NONPOINT-SOURCE POLLUTION
Nonpoint pollutants are those water-degrading substances which
enter waterways from diffuse or non-distinct sources. Nonpolnt-source
pollutants are generally not confined to discrete conveyances, thus
treatment at the source 1s usually Impossible. The nature of
nonpoint-source pollutants 1s generally similar to that of point sources,
but the mode of transport to waterways may differ.
CATEGORIES OF NONPOINT-SOURCE POLLUTANTS
Sediments
The principal polluting agent generated by nonpoint sources as
a group is sediment. The greatest loading of sediment is attributed
to cropland runoff which may account for over 50 percent of the
loading in fluvial systems (EPA, 1973 a). Other farming operations,
silviculture, construction and mining activities also contribute
substantial sediment loads to streams and lakes. While sediments
themselves act as primary pollutants, they also transport a wide
range of attached or sorbed materials which may act as primary con-
taminants or as carriers of other pollutants.
Minerals and Acids
Another major class of nonpoint-source pollutants includes
various minerals released by man-induced exposure of bedrock and
natural mineral phases to weathering, thus enhancing the mobility
of the product. These processes generate add mine drainage and
enhance salinity and toxic metal concentrations 1n aquatic systems.
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Pesticides
Chemical pesticides which are released directly into the
environment during utilization contribute substantially to
nonpoint-source pollution problems. Pesticides include insecti-
cides, herbicides, mitecldes, nematocides, rodenticides, fungi-
cides, plant growth regulators, and deslccants, all of which are
used extensively in agriculture and silviculture. Many pesticides
used are resistant to degradation, and their metabolites or
degradation products may persist or accumulate 1n aquatic eco-
systems impacting the entire food web, up to and including man.
Nutrients
Nutrient elements, particularly nitrogen and phosphorus, also
constitute a class of nonpoint-source pollutants. Phosphorus 1s
of special concern because of its role in eutrophication. Nitrogen
is also involved in the eutrophication process and nitrate and
ammonia nitrogen species are toxic to animal life.
Organic Substances
Natural and synthetic organic waste materials are generated
in part by nonpoint sources. Most of the natural organic materials
(e.g., livestock wastes, forest Utter, crop debris) are readily
degradable and upon reaching a water body may create a heavy oxygen
demand on the system. Many synthetic organic products are less
easily degraded (e.g., petroleum products) and may cause serious
problems in aquatic systems. Such organic products as polychlori-
nated biphenyl compounds (PCB's) which are very resistant to degra-
dation have in recent years become ubiquitous components of the
environment.
Heat
Heat can be considered a class of pollution derived in part
from nonpoint sources as alteration of the thermal regimens of
water bodies is frequently brought about by modification of channel
configurations and changes 1n the stream bank and watershed vege-
tation.
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Microorganisms
Microblal contamination 1s an additional distinct class of
nonpoint pollution. Pathogenic microblal organisms originating
from livestock wastes may be transmitted to surface waters. The
extent of this problem 1s unknown, but 1t remains an area of
concern.
Radioactive Materials
Radioactive pollutants constitute a final class of nonpoint-
source pollutants. Radioactive pollutants are generated as by-
products of certain mining operations and fossil fuel production
and combustion. The radioactive mineral mining industry is also
a source of nonpoint radiation. Extensive continuous monitoring
reveals that, except in a few Isolated cases, levels of radio-
activity in aquatic systems are below levels judged to be
hazardous.
SOURCES OF NONPOINT POLLUTANTS
The principal human activities which result in nonpoint-source
pollution of surface waters are agriculture, silviculture, mining,
construction activity and hydrographic modification. Potentially,
each of these activities could release a myriad of pollutants as
discussed below.
Agriculture
Agriculture has long contributed a number of pollutants to
the aquatic environment, and recently many new synthetic materials
have been developed for use 1n agriculture, expanding the Inventory
of possible pollutants.
Nonpoint sources of agricultural pollutants fall into two
broad classes: those resulting from the cultivation of food or
forage crops, and animal wastes. In the former class, sediment
is probably the chief pollutant in terms of Impaired utility of
water bodies, and its mode of origin, I.e., erosion from crop-
land, constitutes a major threat to the stability of the agri-
cultural economy. Approximately 3.6 billion metric tons of
sediment per year are eroded from cropland 1n the United States
and it is believed that one half of this sediment finds its way
into the Nation's lakes and streams (Holeman, 1968). While
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sediment transport 1n streams 1s a natural process, the rate of
transport 1s very sensitive to the vegetatlonal and climatic status
of the drainage area. The gross alteration of vegetatlonal patterns
usually enhances surface Instability and, therefore, increases
credibility. Agricultural methods have been altered to decrease this
problem 1n some areas, but a concerted nationwide effort will be re-
quired to control this source of pollution.
Relatively low costs of commercial fertilizers and the necessity
for higher economic yields have 1n recent years resulted in Increased
usage of commercial fertilizer 1n agricultural operations. In 1972
about 37 million metric tons of commercial fertilizers were consumed
in the United States, about 75 percent of which was used in agricul-
tural activities (EPA, 1973 a). The national average composition for
the nutrient elements 1s about 20 percent nitrogen, 5.2 percent phos-
phorus and 8.8 percent potassium (EPA, 1973 a). Regional soil
conditions dictate that the composition used 1n any given locality
may deviate substantially from the national average. Rates of nutrient
losses from cropland are a function of precipitation or other applied
water, temperature, soil type, crop grown and cultivation methods used.
It is not known what percentage of the total quantities of nutrients
applied via commercial fertilizers actually reaches waterways, but
data Indicate that runoff from rural watershed represents a significant
fraction of phosphorus and nitrogen appearing in our surface waters
(Verduin, 1970; Goldberg, 1970).
Total quantities of pesticides used in domestic agriculture have
increased steadily over the years. Pimentel (1971) estimated that
of the 453,600 metric tons (1 billion pounds) of pesticides applied
domestically during 1970, about 70 percent was used on farms. Agri-
cultural pesticides may enter the aquatic environment directly or
indirectly. The direct route involves application to waters for
control of specific aquatic organisms (e.g., aquatic weeds, algae,
insect pests, etc.) and drift from aerial application to adjacent
farmlands. Primary Indirect routes include overland runoff, vola-
tilization and subsequent atmospheric washout, and discharge of
wastewater contaminated by cleaning sprayers and containers. Few
data are available to relate quantities of pesticide applications on
farmland to residue levels in water bodies, but overland runoff 1s
considered to be a major source of pesticides in the Nation's water-
ways.
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Irrigation poses a special threat to streams, particularly 1n the
Western States which contain about 90 percent of the Irrigated land 1n
the United States. Irrigation agriculture accounts for approximately
85 percent of the total national water consumption, and as much as
65 percent of the water applied during Irrigation 1s lost to the
atmosphere through evaporation and transpiration (Jenke, 1974). Water
that is returned to the surface or subsurface systems 1s termed Irri-
gation return flow. The concentration of substances in applied
irrigation waters is Increased by evaporation and transpiration, and
return flows also pick up natural salts from the soil. Consequently,
irrigation not only diminishes the quantity of water 1n a system through
consumptive uses, but degrades the quality as well by returning waters
with high concentrations of salt and other dissolved and suspended
materials to the system. Although increases 1n salinity concentrations
in hydrologlc systems which receive Irrigation return flows pose the
major problem 1n waterways in Irrigated areas of the country, degradation
of water quality from other causes 1s also of concern. Surface runoff
water from Irrigated lands may contain high levels of pesticides, fertil-
izers, organic debris, sediments, heavy metals, bacteria (Including
pathogens), and other pollutants derived from the land and transported
to lakes and streams.
The volume of animal wastes produced in the United States 1s about
10 times that produced by the human population (EPA, 1973 a). Animal
wastes constitute a major source of organic loading to waterways, with
the primary Impact coming from confined animal populations.
The high concentration of wastewater in a relatively small area
precludes rapid biological degradation, and the pollution potential
1s increased greatly over non-confined animals. Some animal waste
generated in pastures, however, may reach waterways, since livestock
tend to congregate 1n watering, resting and supplementary feeding
areas, thus concentrating the wastes. Livestock wastes, in addition
to increasing the nutrient and organic load 1n waterways, are also
a source of pathogens.
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Silviculture
Silviculture, the commercial management of trees, has a high
pollution-generating potential. The principal pollutant associated
with silvicultural activities is sediment. Since operations of
harvesting alter or disrupt surface cover, surface soil is subject
to erosion and subsequent transport into adjacent streams. Surface
runoff also carries synthesized compounds such as pesticides and fire
retardant chemicals used in forest management. Also of significance
is the alteration of the thermal budget resulting from changes in
solar penetration in runoff areas and along stream channels.
Surface disruption during harvesting occurs during access road
construction, as well as during the actual timber removal operation
in harvesting and yarding/staging areas. Post-harvesting surface
disruption results from increased surface exposure to raindrop impact,
loss of the stabilizing effect of live root networks, and decreased
or eliminated input of forest debris which increases the credibility
of the forest soils.
Surface disruption is not an exclusively man-induced factor
in forested areas. It can be promoted by windstorms, drought, ex-
tremely heavy downpours, and rapid snow melt. Fire, disease, and
insect infestation also contribute to surface changes which lead
to increased erosion. Alteration of surface vegetation increases
solar input to surface soils and waterways, leading to higher tem-
peratures of water bodies.
A wide range of pesticides 1s utilized in forest management
including insecticides, fungicides, herbicides, and rodentlcides.
Since these materials are clearly not a part of the natural setting,
their role in water pollution 1s pronounced. Careless aerial appli-
cation of pesticides results in direct input into lakes and streams.
Aerial application of fertilizers and fire retardants to
forested lands may result in direct loading to streams. Although
not applied as a fertilizer, fire retardants usually contain either
phosphates or ammonia, thus having much the same effect as fertilizers
in waterways.
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Mining
Mining activities, present and past, have created severe water
pollution problems in lakes and streams. The pollutants resulting
from mining are both an expression of the mining procedure used and
the types of material being extracted. Each mining method has its
own selected problems of pollution potential and must be analyzed
accordingly. Pollutants generated are often very much dependent on
the ore mineral assemblage.
Unlike other nonpoint sources, the primary pollutant from mining
activity is not sediment, but a water quality degrading solution of
sulfuric acid, iron salts, and other salts. Generally referred to as
acid mine drainage, it results from the oxidation of iron disulfides,
pyrite, and marcasite, which are commonly found within a wide range
of material. Coal mines have been a primary offender, but acid mine
drainage is also a problem in some hard-rock mining areas.
Sediment can be a major pollutant from mining operations, espe-
cially in strip mining areas which may Involve large tracts of land.
This 1s particularly true 1n some coal and Iron ore mining operations.
Tailings, the spent residues of ore extraction, are often very fine
grained and, therefore, are easily mobilized by runoff.
Mining operations directed at recovering some specific compound
or metal may induce the entry of that same material into the aquatic
environment as a pollutant. Leakage of this sort may be very dangerous
if the escaping material is toxic at low concentrations or undergoes
enhancement in the biological or geochemical chain to toxic levels.
Leachates from tailings and spills can add a variety of materials as
well. These materials Include trace elements in ore bodies which may
not be extracted in the milling process, but can be lost to streams
as a pollutant in concentrations that may be toxic to the biota of the
stream.
Of special concern is the composition of runoff and leachate
from mining activities associated with extraction and recovery of
radioactive ores. Tailings from uranium operations in the Colorado
River Basin and South Dakota have been subject to extensive study.
Although radioactivity 1n these areas is not above permissible levels,
long-term effects are not clearly known. Radioactive nuclides, as
trace elements in coals, have been observed in significant concen-
trations in the Allegheny River (Caldwell, et al., 1970). Coal de-
posits in the West also contain uranium, but less information is
available on their effect on water quality. Clearly,-radioactive
nuclides may be a significant pollutant from mining of carbonaceous
materials such as coal and oil shale.
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Salinity increases in streams in the Western United States have
been related in the past to mining operations. It is estimated that
about 20 tons per day of dissolved solids enter streams of the San
Juan Mountains which drain to the Colorado River (Blackman, et al.,
1973).
Other pollutants which may result from mining operations are
phosphates and nitrates used as fertilizers to promote groundcover
on various types of debris created during mining operations. Pesti-
cides of various sorts may also be leached from disturbed soils 1n
the mining area. Microbial contamination associated with wastewater
generated at the milling and mining sites may also be of significance.
Construction
Construction of facilities such as highways, dams, housing
developments and other energy consuming or producing sites contribute
nonpoint pollutants to waterways. The principal pollutants generated
by these activities are sediments and storm water. Other pollutants
are sorbed to sediment or mobilized by the same processes which entrain
detrital debris. These Include organic matter, fertilizers, pesticides,
and bacteria which were reasonably well stabilized in the soil. Addi-
tionally, potential pollutants are produced by the full range of
chemicals and products of waste-generating processes involved in con-
struction activities.
Hydrographic Modification
Hydrographic modification includes procedures that change the
movement, flow, or circulation of any navigable waters or groundwaters.
These include changes caused by the construction of dams, levees, chan-
nels or flow diversion facilities. Interpreted in the broadest sense,
this could include almost all terrestrial modifications, since they all
alter the patterns and composition of the runoff that eventually enters
navigable streams. However, this overview is restricted to effects
resulting from direct modification of navigable streams or channels of
high order ephemeral streams.
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Channelization involves modifying the streamway in an effort to
improve flow in the channel, thus resulting 1n substantial alterations
of habitats; the creation of impoundments on streams causes significant
changes by creating a lake where there was once flowing water; and
dredging operations, gravel mining and the disposal of generated waste
substantially alter characteristics of the waterways. Generally, these
activities in addition to altering the physical nature of the channel,
induce changes in the thermal patterns of the waterway.
Channelization -
Channelization has been promoted and practiced by a number of
government and private agencies. The principal Federal agencies
involved in this activity are the Soil Conservation Service, U.S.
Army Corps of Engineers, and the Bureau of Reclamation. Channelization
is usually directed at flood control and improvement of drainage char-
acteristics.
Sediment is "the most ubiquitous of all pollutants associated
with channelization" (EPA, 1973 c). During construction activities
in channelization, sediment is a very pronounced pollutant and fre-
quently remains a serious problem after alterations have been stabi-
lized by vegetation.
Alteration of stream temperatures, subsequent to channelization
may induce a change in the aquatic communities. Components of the
existing communities which are susceptible to wide fluctuations in
temperature and dissolved oxygen levels may be unable to adapt to
the new thermal regimen, and eventually may be replaced by species
with wider tolerance ranges. Although all life stages of the biota
may be subjected to stress conditions by these changes, disruptions
to reproductive patterns seem to have the greatest impact upon com-
munity structure.
Increased velocity of water in channelized streams has a tend-
ency to extend the downstream distribution of sediments and other
pollutants introduced into the stream. The velocity drop associated
with the downstream non-channelized reaches may result in deposition
and upstream migration of sediments into the channelized segment,
clogging the channels and defeating the purpose of channelization.
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Impoundments -
Manmade Impoundments or reservoirs are lakes formed by the damming
of fluvial systems. Impoundments have many features 1n common with
natural lakes. However, the former are distinguished by two general
characteristics: (1) rates of discharge from many reservoirs are
subject to manipulation which may result 1n a greater fluctuation in
water level and volume than normally occur 1n natural lakes; and (2) in
direct contrast to natural lakes, outlets of Impoundments often dis-
charge water from a location other than the surface. These two factors
not only cause changes in the quality of the Impounded waters, but also
1n the water downstream.
Periodic drawdown of an impoundment is an example of manipulation.
This process may expose large expanses of the littoral zone to the
atmosphere. Such exposure reduces the volume of the hypollmnion and
the acreage available to sustain rooted aquatic plants in addition to
destroying biotic shelters and compacting sediments. The organisms
themselves may suffer from exposure to the atmosphere. Nevertheless,
drawdown and eventual reflcoding can be effective lake management tools
to provide suitable habitats for desirable organisms and to Influence
nutrient availability.
The practice of discharging hypolimnetlc waters, as is done 1n
some reservoirs, has a profound effect upon downstream reaches. The
release of hypolimnetic waters may create an environment suitable for
a cold water fishery in a stream which once supported only warm water
species. Primary productivity of nutrient-rich hypolimnetic waters may
also be increased by release to a flowing system and subsequent exposure
to Increased light intensity. Once the nutrient-rich waters are dis-
charged to a flowing system, the response of the biota may be immediate,
resulting in greatly Increased photosynthetlc activity.
The creation of impoundments 1n a once fluvial setting requires
an adjustment by the biota 1n response to the physical and chemical
changes associated with the new lentic environment. The extent of
the biological change is dependent upon the magnitude of change in
hydraulic character, and other physical and chemical alterations.
Biological communities requiring flowing waters will obviously give
way to lentic species, while terrestrial communities will be replaced
by aquatic plant and animal associations. Impounded waters will, to
an extent, reflect the chemical nature of the inundated basin, thereby
further influencing the composition of the biota. Since Impoundments
are frequently formed by flooding fertile bottom lands, the impounded
water may be rich in nutrients and other dissolved and suspended
materials. Also, depending upon the nature of the landscape, minerals
may be released to the water from rock formations and soils. Physical
changes involving temperature regimens, sedimentation rates and turbidity
also occur as a result of impounding flowing waters.
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Mining Gravel From Streams -
The mining of gravel and sand from stream channels cannot be
easily classified as either mining or hydrographlc modification.
However, the effect of this activity on stream flow seems to be
more closely related to hydrographlc activities than to the majority
of mining activities.
The chief pollutant generated by mining gravel in streams is
sediment, resulting in increased stream bedloads and high turbidity.
The resettling of fine materials such as clays and silts 1n the
mined pit may retard water infiltration to the groundwater, thereby
restricting recharge 1n the vicinity of the mining site. Bull and
Scott (1974) suggest that low water stream bed elevation, and the
natural range thereof, may provide a good parameter from which to
observe changes resulting from gravel mining operations. They suggest
that the physical features of the channel may give meaningful and
inexpensive ways of observing changes in the fluvial nature of the
system.
Other pollutants are mainly those closely associated with the
sediments including nutrient elements, heavy metals, and any synthetic
compound sorbed to the surfaces of particles.
Dredging and Dredged Spoil Deposition -
Dredging is usually directed at maintaining navigable channels
in rivers and estuaries. The U.S. Army Corps of Engineers has been
delegated the task of conducting dredging operations in navigable
waters, as well as issuing permits to others who are conducting this
type of operation. The Corps was also instructed in the 1970 Amend-
ments to the River and Harbors Act to establish a study of the en-
vironmental impact of dredging and the disposal of dredging wastes.
From this study, new techniques in both dredging and spoil handling
were outlined. In the Federal Water Pollution Control Act Amendments
of 1972, the Administrator of the EPA was authorized to compile
guidelines for establishing disposal sites.
Mechanical methods of dredging utilize excavation equipment
such as draglines, shovels, and trenching equipment, which are
located on the banks or on barges. Hydraulic dredging Involves
disposal via a pipeline.
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The greatest pollution hazard to the aquatic environment Is not
the dredging operation per se, but the disturbed sediment and the
wide range of sorbed materlaTs. These Include the full range of
materials generated by man, particularly Inorganic nutrients such
as phosphorus and nitrates, toxic metals, pesticides, and organic
materials such as those occurring 1n sewage sludge. Dredging In-
creases the exposure of these materials for mobilization, either
with suspended sediment or from leaching processes. Secondly, the
suspended fraction of the dlstrubed bottom sediment degrades water
quality and detrimentally Impacts the biota.
Dredging has other Indirect manifestations. Since the channel
geometry is usually changed, the velocity, current configuration and
sedimentation patterns are altered. Aquatic life forms are often
greatly reduced during dredging, and the altered bottom situation
is often hostile to repopulation.
Disposal of dredging operation wastes results in increased
water turbidity. Waste disposal at terrestrial sites close to the
channel may add pollutants, while dewatering either the stream or
groundwater.
16
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PREDICTION OF NONPOINT-SOURCE POLLUTION
The ability to predict the rate and nature of pollution loading
to a given waterway with accuracy 1s an essential requirement for
planners and engineers concerned with nonpolnt-source pollution
control. Various methods have been devised for predicting nonpolnt-
source pollution varying 1n levels of sophistication from simple
rules of thumb to highly complicated computer procedures. A requi-
site feature of any prediction procedure 1s a sound data base upon
which to operate. Regardless of the level of sophistication of a
prediction model, the Information generated can be no better than
the baseline data which formed the foundation for predicting future
events in a given water course. Many prediction models currently
available have applications to nonpolnt pollutants originating from
several sources (e.g., sediment). However, 1n the following dis-
cussion, the reader 1s briefly Introduced to a few of the more
common techniques used to predict rates and types of pollutants
generated by various activities.
AGRICULTURE
The literature covering agricultural pollution prediction methods
is extensive. Since a given drainage basin undergoing modest agricul-
tural activity has a large number of input sites, a prediction method-
ology will involve input/output evaluation coupled with reaction
(chemical and biological) modification during transport and sedimen-
tation (EPA, 1973 a).
Prediction methods exhibit varying degrees of accuracy and
completeness. Of the polluting materials from agriculture, sediment
is the most prominent and has been most subject to extensive investi-
gation. Table 1 presents a summary of sediment prediction methods
which have been field tested and found to be reasonably accurate.
17
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Table 1. SUMMARY OF SEDIMENT PREDICTION METHODS
PROCESS
Prediction Method ErosionTransportDeposition
1. Empirical:
Ellison (1945) X
Musgrave (1947) X
Universal Soil Loss Equation X -
(Wischmeier and Smith, 1965)
Einstein Bedload Function - X
(Graf, 1971)
Colby Modified Einstein X
(Graf, 1971)
Toffaleti Total Load Method X X
(Graf, 1971)
Lacey's Silt Theory - X X
(Fleming, 1972)
Pemberton Modified Einstein - X
(Pemberton, no date)
Reservoir surveys: - X
ARS
SCS
Corps of Engineers
Bureau of Reclamation
U.S. Geological Survey
2. Statistical:
Flaxman (1972) - - X
Sediment rating-flow duration - X
U.S. Geological Survey
Bureau of Reclamation
Corps of Engineers
Woolhiser's Deterministic XX X
Watershed Model (EPA, 1972)
18
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Table 1 (continued). SUMMARY OF SEDIMENT PREDICTION METHODS
PROCESS
Prediction Method ErosionTransportDeposition
3. Simulation:
ARS Upland Erosion Model X -
(Foster and Meyer, 1972)
ARS USDAHL-73 Watershed Model XX X
(Hoitan and Lopez, 1973)
ARS "ACTMO" Chemical Transport X
Model (Onstad, 1973)
Negev's Watershed Model XX X
(Negev, 1967)
Stanford IV Model XX X
(Crawford and Linsley, 1966)
Hydrocomp Simulation XX X
(Crawford, 1970)
Huff Hydrologic Transport Model X
(Huff, 1972)
Royal Institute (Sweden) Hydro- XX X
logic Model (Cawood, et al., 1971)
Snyder's Parametric Hydrologic X X
Model (Snyder, 1972)
19
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In predicting and evaluating the nature and extent of pollution
from agricultural sources, two modes of Investigation may be followed,
one of which is the material balance method.' Stated simply, the
magnitude of pollution is related to the amount of material (I.e.,
fertilizer, pesticides, etc.) added, less that fraction which is
retained by the soil (EPA, 1973 a). Unfortunately, this may be a
complex system and the magnitude of some Input may be unknown. In
the second investigative method, the water monitoring framework is
designed so that samples reflect the pollutant component in the
selected drainage area. Sampling locations are designed to provide
the maximum contrast between land use and geographic features. Such
parameters as rainfall, basin geometry discharge characteristics, and
chemical and physical reaction rates are weighed to make site
selections. Baseline data as acquired and retained by the U.S.
Geological Survey (USGS) and EPA provide useful background Information.
Clearly, the occurrence of concentrations of a given substance over
the historical concentration values will strongly suggest loading from
some man-related activity.
SILVICULTURE
The generation of sediment in forested areas can be estimated
by evaluating several surface factors and eroslonal modes. The
four modes of interest are: (1) surface erosion, (2) gully erosion,
(3) mass soil movement, and (4) channel erosion (Flaxman, 1972).
Surface erosion 1s largely determined by soil, rainfall char-
acteristics, topographical configuration, vegetational cover, and
erosional control practices. By examining these factors, the
Universal Soil Loss Equation (Wischmeier and Smith, 1965) and the
Musgrave Equation (Musgrave, 1947) were developed, Although
orginally designed for agricultural areas, these relationships
have been found to be applicable in forested areas (Flaxman, 1972).
Contributions to pollution by mass soil movement and channel
erosion can be estimated 1f aerial photography of the areas of
interest has been completed over a period of several years. Changes
in forest canopy may limit the accuracy of this type of estimation.
Gully erosion may also be estimated from aerial photography.
Other pollutants generated during activities associated with
silviculture cannot be accurately predicted at the present time.
Therefore, the next best course of action would be an input/output
evaluation of pollutant expression in waterways from known activities
in the drainage basin.
20
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ACID MINE DRAINAGE
Development of models useful 1n predicting add mine drainage
and leachate from refuse/soil piles has been primarily keyed to
pyritic oxidation (Morth, et al., 1972). These types of models
are applicable to most coal mines as well as hard-rock mines.
Others are keyed to sulfur content of source material (EPA, 1971).
In detecting the manifestation of add mine drainage in streams,
a useful tool is the anion-catlon balance outlined in the 13th
edition of Standard Methods for Examination of Water and Wastewater
(APHA, 1971T This tool gives a straightforward methodof handling
analytical data from streams suspected to have acid mine drainage
loading. Nomograms using this relationship have been developed and
presented along with methods for translating raw data to a form where
anion-catlon balance can be charted (EPA, 1973 a). Hem (1970) also
describes several models which use this concept in interpreting water
quality data.
IMPOUNDMENTS
Water quality changes caused by reservoirs have been investi-
gated using empirical, physical, and mathematical modeling approaches.
Most of these systems require field data to verify or calibrate the
predicted changes. Empirical methods are usually reservoir specific,
and while usually inexpensive, these methods tend to be inflexible
and require extended observational base. Physical models tend to be
directed at the hydraulic characteristics of the system. Mathematical
models usually attempt to evaluate an aggregation of variables in
determining water quality. Basin hydrology and stratification within
reservoirs are among the factors examined. Equations are created which
attempt to predict Water quality as influenced by various factors at
various points in space and in time 1n the system.
DREDGING
Prediction of the extent of water pollution caused by dredging
requires an evaluation of the proposed target site. Existing water
properties, biota, and historical water pollution of the site area
should be examined. Hydraulic alteration can be partly evaluated
from physical models. Where dredging will Intersect aquifers, the
effect of these added waters will also need to be evaluated.
21
-------
In predicting pollution from spoil disposal in water, the exact
characteristics of the solids must be known. The properties of the
disposal site such as gradient, current and velocity configuration,
and flow volume must be understood. Spoil deposition pollution
prediction on terrestrial sites requires that the properties of
the spoil be known, as well as the erosional/drainage situation
at the disposal site.
22
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NONPOINT-SOURCE MONITORING
The Intent of this section 1s to present a broad overview of
monitoring strategy and techniques that can be applied to the Iden-
tification and assessment of nonpolnt-source pollution.
NONPOINT-SOURCE MONITORING STRATEGY
To measure the effectiveness of nonpolnt-source control
1dentW"9 and assessing nonpolnt sources of
PL 92 500 s TM e Prma:y m9 Progm. P-l by
6' °n t the
Dhvslr.1 Mn« ' '^ S*Sem W meaSUre the
physical, biological and chemical trends within the rivers of each
lS«!?!!rlJSi 1974)'< The mon1tor1"9 Astern Is designed to prolde
0
-------
In establishing the primary network sampling locations, historical
water quality data should be used when available. These data provide
valuable Information for establishing location, frequency, and extent
of sampling required to adequately depict water quality trends as well
as to provide baseline data on ambient water quality. Stream flow data
give added meaning to the sampling information, thus sampling sites
established in close proximity to existing stream gauging stations
provide maximum information.
WATER DATA ACQUISITION
Two basic questions that must be addressed at this time are:
What parameters should be measured, and what method should be
employed to monitor them?
At one time or another, it is conceivable that almost
every parameter measurable will be needed on a particular
stream. It is impossible, however, to measure every para-
meter, and consequently, sound judgment must be used in
making the final decision. This decision must relate to
the particular situation associated with the sampling point.
Again, however, it may not be very practical to have a dif-
ferent set of parameters to be measured at every sampling
station. Some compromise must be developed with respect to
the various situations that occur in a State (EPA, 1973 1).
A few basic parameters common to every sampling point in the
primary network give continuity to the data from site to site and
from State to State. The selection of the other parameters to be
monitored depends upon specific requirements related to the type
of nonpoint-source category and the media being sampled.
The instability of some parameters dictates that they be
measured in the field, while others must be measured 1n the labora-
tory because of the complex analytical procedures required for
sensitive determination.
Table 2 (Parameter Matrix) is organized into two parts. The
first part consists of the parameters which may be measured in situ,
and the second part lists those parameters that are usually measured
in the laboratory. Included are indications of the relative Impor-
tance of each parameter as associated with the five general categories
of nonpoint-source pollution expressed 1n the first two parts of this
report.
24
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Table 2. PARAMETER MATRIX
Field Measured Parameters
Turbidity
Temperature
Specific Ions
Specific conductance
IP"
Oil and grease
How Rate
Dissolved oxygen
Laboratory Measured Parameters
Acidity
AlkaUnlty
Chemical oxygen demand
Total organic carbon
Specific ions
Heavy metals
Suspended solids
Total dissolved solids
Nitrate
Nitrite
Nitrogen. Kjeldahl
N1 troqen , ammonl a
Total nitrogen
Organic pnospnorus
Total pnospnorus
Chlorinated nydrocaroons
Organophosphates
Carbamates
Agriculture
P
P
P
P
P
N
P
P
S
P
P
P
P
S
p
p
p
p
p
p
p
p
p
p
p
p
0)
+J
u
•r-
>
•p-
«/>
P
P
P
S
p
N
P
P
s
s
s
s
s
s
s
p
s
p
p
p
0>
•r*
c
•^
p
~p
p
T
1
!
1 ft
p
s
£
^
5
p
p
E
^
s
s
s
s
s
s
N
Construction
P
'
5
S
5
'
S
s
»
N
>
'
S
s
s
s
s
N
Hydrographic
Modification
Y
>
»
1
S
S
s
p
N
>
'
S
s
s
s
N
P = Major component
S = Secondary component
N = Minor significance
25
-------
Field Measurements With Contact Sensors
For some monitoring situations, automated sensors may be utilized
to continuously measure and record selected parameters. The contact
sensing devices used for making parametric measurements 1n water are
either electro-chemical or electro-mechanical 1n nature. A specific
parameter of water Interacts sto1ch1ometr1cally with the sensor to
generate an analog voltage or current that 1s predictable and repro-
ducible.
The sensors can be placed physically at the exact point in the
stream where the measurements are desired; the signal processing
electronics can be separated from the sensors and located ashore,
or the water can be piped from the sampling'point to the sensor
location, thus having the sensors closer to the signal processing
electronics. Pumping the water may change some parameters; however,
the pumping method allows an Integrated sample of the stream to be
measured with one set of sensors.
Electronic contact sensors for water quality evaluation and
trend monitoring make possible an automated sampling station with
continuous recording of 1n situ data. This same system permits
the data to be telemeterlcT at predetermined finite Intervals to any
central point.
It 1s possible to build a monitoring system for suitable para-
meters that, if undisturbed, will maintain Its calibration accuracy
and repeatability for approximately 1 month, unattended.
Certain key parameters providing an overall indication of water
quality can be measured automatically and continuously without regard
to expected pollutants 1n an area. Significant changes 1n such para-
meters provide an alert for closer examination and more detailed
sampling.
The following summary discusses those parameters which are
suitable for monitoring with automated contact sensors.
26
-------
Turbidity -
Turbidity is an expression of the optical property of water
to scatter and absorb light rather than transmit it in straight
lines through the sample. Some electronic turbidity sensors
measure the amount of light deflected to the side of the incident
light beam (nephelometer), while other sensors measure the percent-
age of light transmission on a fixed path length through the water
sample (transmissometer) and extrapolate turbidity data; however,
this is not a true measurement of turbidity.
The unit used for measurement of turbidity 1s the Jackson
Turbidity Unit or JTU. Zero JTU denotes perfectly clear water;
1,000 JTU approaches the upper limit of turbidity. The larger
number (JTU) Indicates more light is deflected and absorbed by
the suspended particles and colored substances in the water.
Since the electronic turbidity sensor 1s an optical device,
any deposits or algal fouling on the optical windows will give
erroneous results. The sensor should be oriented so that the
stream flow accomplishes a natural flushing action for the optics.
In highly enriched environments, the windows will still require
frequent cleaning.
Temperature -
The four basic types of electronic sensors used for measuring
temperature are thermocouples, resistance thermometers, thermistors,
and semiconductor devices. The thermocouple develops an electrical
potential across a junction of two dissimilar metals that varies
directly with temperatures. The resistance thermometer 1s a coll
of metal wire, usually platinum or nickel, whose resistance varies
directly with temperature. Thermistors are non-metallic beads or
discs whose resistance varies Inversely with temperature. Semi-
conductor temperature sensors are usually silicon diodes whose
nominal forward voltage drop 1s 600 mv. This voltage varies in-
versely with temperature. Each of these types of transducers re-
quires analog circuitry to convert the sensor output to a
direct-reading voltage analog.
Resistance thermometers are the most precise and some are quite
linear over a broad temperature range; however, they are the most
expensive to construct. Thermistors are linear over a narrower
range and tend to drift slightly; they are the least expensive type.
Semiconductor elements are quite linear over a broad temperature
range, and are relatively Inexpensive and stable. Sensors with
narrow linear ranges require complex linearization circuits when
27
-------
operated outside of that range. The calibrated accuracy of the
temperature sensor should be +0.1° C throughout the range of 0 C
to 40° C; Us time constant sfibuld not exceed 1 minute; and 1t should
retain the calibration accuracy for greater than 4 weeks.
Specific Ions -
Sensors are available to measure over 20 different specific
ions. At this time, only a few have proven reliable in an unat-
tended field environment. These Include the chloride and the
fluoride sensors and the divalent calcium/magnesium or hardness
sensor. The chloride sensor, however, has limited utility in
fresh water as reprodudbiHty is poor 1n solutions of low chloride
concentrations or low ionic strength.
The units of measurement for specific ion sensors are decimal
molar concentration or milligrams per liter. Specific ion sensors
require temperature compensation.
Specific Conductance -
Conductance is a relative measure of ionic strength of the
sample; it is the inverse of the electrical resistance. In a
fresh water environment the unit of measure 1s micromhos per
centimeter. Conductivity of water varies with temperature; when
corrected to a standard 25° C, this value 1s termed Specific
Conductance.
Conductance sensors are basically of two types. The first
has conducting electrodes that are exposed directly to the water.
An electrical potential is applied either directly to the measuring
electrodes or to two other electrodes. The current in the sample
is directly proportional to the conductivity. Another technique
is to apply an alternating potential to the electrodes to reduce
the galvanic effects and reduce electrode oxidation. This type
of sensor requires regular cleaning to remove chemical and bio-
logical deposits that may mask some of the electrode surface.
The second type of sensor is inductive in nature; two toroidal
coils are immersed in the sample, one of which is driven with an
alternating current. This signal 1s inductively coupled to the
second torold by the conductivity of a water column that passes
through both colls. The geometrical arrangement of the coils and
the size of the water column are critical 1n the design of the
type of sensor; the associated circuitry is more complex than the
28
-------
exposed electrode approach. However, problems of deposits on the
electrode are almost completely eliminated. The Inductive sensor
has been used most commonly 1n the marine environment where corrosion
1s an extreme problem. The National EutropMcation Survey of the EPA
has used 1t quite successfully 1n fresh water.
fiH -
By definition, pH Is the negative logarithm of the hydrogen
ion concentration. The practical sensor for measuring pH is an
electrode made of a special pH sensitive glass. The electrode 1s
used 1n conjunction with a reference electrode. They are available
either together, in the form of a single combination electrode, or
separately. Most combination electrodes and reference electrodes
are pressure sensitive. However, some companies are now manufacturing
pressure compensated combination electrodes and pressure compensation
flowing junction reference electrodes. The Lazaran Process reference
electrode 1s specified to operate to a pressure of 150 pounds per
square inch, requiring no electrolyte seepage and no refilling. When
this electrode is used in conduction with a process glass pH elec-
trode, the pair may be continuously submerged. The only maintenance
required is periodic cleaning.
The electrodes generate an analog voltage proportional to the
pH of the sample. The voltage 1s positive for acidic and negative
for alkaline samples. The pH sensor requires a very high input
Impedance amplifier because of Its own high internal impedance. The
sensor is temperature sensitive and must be temperature compensated.
Oil and Grease -
Obtaining quantitative and qualitative data on oil and grease
requires laboratory analysis. Sensors now being developed can
electronically detect the presence of an oil film on the water sur-
face. This Indication is important as an alarm mechanism.
29
-------
Dissolved Oxygen -
Most dissolved oxygen sensors used 1n water quality studies
use a gas permeable membrane to measure the partial pressure of the
oxygen 1n the water. The oxygen passes through the membrane at a
rate directly proportional to the oxygen concentration or partial
pressure and Inversely proportional to the temperature of the mem-
brane and water. The Inside of the sensor contains a silver and
gold electrode 1n a potassium chloride solution. The oxygen 1s
electrochemically reduced Inside the sensor by a polarizing poten-
tial applied to the silver electrode. The current passing through
the sensor 1s directly proportional to the rate of oxygen being
reduced and thus to the oxygen 1n the water. This current 1s con-
verted to an analog voltage and temperature corrected to give a
dissolved oxygen (D.O.) measurement. Since oxygen 1s being con-
sumed continuously from the water, a flow of water past the sensor
1s required to keep the flow rate through the membrane 1n equilibrium
with the D.O. 1n the sample. If the natural flow rate.1s Insufficient
to accomplish this, some form of mechanical stlrrer must be used with
the sensor. As the membrane fouls or deteriorates, It must be cleaned
or replaced to prevent calibration shift. Process oxygen sensors are
available which retain their calibration for longer than 4 weeks, 1f
undisturbed.
Field Sample Collection
Sample Volume -
In selecting sample volume, several factors require evaluation:
(1) the objectives of the sampling, (2) the type of collecting device,
(3) the concentration of pollutant 1n the water, (4) the analysis or
analyses to be performed on the sample, (5) the time available for
sampling in the case of composite samples, and (6) minimum volumes
necessary for quality control procedures and replicate measurements
that may be desirable.
Some analytical procedures require that chemical preservatives
be added to the sample rendering 1t unfit for other chemical analyses;
consequently, 1t is sometimes necessary to collect multiple samples.
30
-------
Sample Types -
There are three basic sample types:
(1) Grab Sample: A grab sample 1s usually a manually collected
single portion of water. Analyses of properly handled grab
samples measure characteristics of the water at the time the
sample was collected.
(2) Continuous Sample: When points are to be sampled at fre-
quent Intervals or when a continuous record at the sampling
station 1s required, an automatic or continuous sampler may
be employed.
(3) Composite Sample; A composite 1s prepared by mixing together
two or more Individual samples. A volume-Integrated composite
1s prepared by combining Individual portions whose volume 1s
proportional to the flow rate of the stream sampled. This
results 1n a variable volume for the composite obtained over
a fixed time period.
A time composite 1s a mixture of constant volume
portions taken at specified time Intervals. The composite
can be both flow Integrated and time composited, I.e.,
several portions are taken at equal time Intervals with
the volume depending on the flow rate at the sample time.
These composites can be prepared manually or with auto-
matic sampling devices.
Continuous samples are usually the most representative, but
composite samples are acceptable for many purposes. Although a
grab sample reflects the water quality at an Instant 1n time, 1t
Is quite acceptable 1f judgment and discretion are exercised 1n
Its use.
Sampling Procedures and Equipment -
Specific recommendations for sampling procedures and equipment
for the collection of water quality data are described In a pre-
liminary report of the Federal Interagency Work Group on Designation
of Standards for Water Data Acquisition (USDI, 1972) and 1n EPA
publications (EPA, 1973 j).
31
-------
Selection of sampling equipment will depend on the parameters to
be collected. Stream conditions, the physical state of the pollutant,
and physical limitations at the sample site will dictate the specific
equipment most appropriate for collecting a representative water
quality sample.
Sample Preservation -
An extremely significant aspect of the collection procedure is
sample preservation. The physical, chemical, and biological char-
acteristics of the sample will change with time, temperature, and
exposure to light. Therefore, it 1s necessary, In many Instances,
to chemically treat samples to retard bacterial growth; refrigerate
samples to reduce chemical and biological activity; and store samples
in light-proof containers to Inhibit photochemical reactions. Samples
may require one or more of these preservation techniques to maintain
the original characteristics of the sample. No presently available
preservation techniques are universally suitable for all likely
parameters; in situ analysis is often still necessary.
Sample Identification -
An Important factor in sampling 1s the accurate and complete
identification of each sample. A unique sample Identification code
should be used for each station. The use of tags upon which Identi-
fying data may be entered Is satisfactory provided the tags are
moisture resistant and do not become soiled or damaged during use.
Quality Assurance -
Because of the importance of analytical analyses and the resulting
actions which they produce, a program to assure the reliability of the
data 1s essential. It Is recognized that all analysts practice quality
control to varying degrees, depending somewhat upon their training,
professional pride, and awareness of the Importance of the work they
are doing. However, under the pressure of dally workload, analytical
quality control may be easily neglected. An established routine control
program applied to every analytical test 1s Important in assuring the
reliability of the final results.
32
-------
The goal of the quality assurance program 1s to produce accurate
and reliable data. In establishing a program 1t 1s Important to con-
sider the following:
(1) Documentation of monitoring system design.
(2) Standardization of sampling techniques and equipment.
(3) Standardization of analytical procedures.
(4) Establishing a duplicate sampling and analysis program.
(5) Participation 1n Interlaboratory cross-check programs.
(6) Standardization of reporting and feedback Information
systems for users.
(7) Standardization of electronic sensors used for 1n situ
monitoring.
For detailed procedures on laboratory quality control, consult
the Handbook for Analytical Quality Control In Water and Wastewater
Laboratorle? TEPA. 1972).these methods and techniques have been
adopted by EPA laboratories and provide a common base for data
between Agency programs.
Sample Control -
Samples sent from the field to the laboratory should be routed
through a sample control system. The sample should be logged 1n and
all Information pertaining to sample collection should be recorded
on an appropriate sample control form. Each sample should be
assigned a unique laboratory Identification number with parameter
analysis and routing Identified. The data analysis system should
have the provision to keep track of all samples as they proceed
through the required analytical procedures; this Insures against
sample loss or Incomplete sample analysis.
33
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Laboratory Analytical Procedures
Physical, chemical, and microbiological analyses 1n stream
measurements are specified 1n regulations published 1n 40 CFR,
Part 35, Appendix A (Quarles, 1974), which Includes selected
methods from Standard Methods for the Examination of Water and
Wastewater (APHA. 1971). AnnuaT~Bbok~bf Standards,Tart 23/water;
Atmospheric Analysis (ASTM. 1973Tan"d"Wethods for Chemical Analyses
of Water and Wastes (EPA, 1971). These methods are required to be
used by tfie States 1n primary monitoring network sample analyses.
Remote Sensing
Remote sensing techniques, such as Infrared thermal mapping,
multispectral scanning and satellite Imagery, emerged as valuable
aids in assessing the need for, and effectiveness of, nonpolnt
pollution control programs. Infrared aerial photographic and
mapping reconnaissance surveys provide a rapid means of Identifying
sources and potential sources of pollution and delineating areas of
high sediment loads in major water bodies. It 1s frequently possible
to relate land-use practices and landscape characteristics to sediment
loads 1n waterways utilizing such techniques.
The verification of mining, construction, and farming land-use
practices can be accomplished in a cost-effective manner by use of
high resolution aerial photography. These services are now available
commercially. Both the EPA and the National Aeronautics and Space
Administration (NASA) have developed techniques for Identifying
land-use practices from photographs, and NASA has published two
handbooks on the use of small-scale photography for land-use mapping
(NASA, 1972 a) and classification (NASA, 1972 b). These handbooks
were designed to provide simple procedures by which large land areas
can be economically categorized. These studies have shown the utility
of such techniques applied to forestry, hydrology, agriculture, and
mining. The reports provide procedures particularly useful to agencies
or planning groups in need of land-use Information, and operating with
limited resources of personnel and funding.
Remote sensors which may be suitable for measuring relative river
centerline suspended sediment and salinity concentrations are 1n the
planning stage. These instruments would be of tremendous assistance
in locating nonpoint pollution sources for purposes of designing
ground-based monitoring networks and surveillance systems. It may
also be possible to utilize a combination of ground-based and airborne
sensors to determine suspended sediment and salinity dispersion patterns.
Relationships could be established by preparation and verification of
models.
34
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REFERENCES
American Public Health Association (APHA). 1971. Standards methods
for the examination of water and wastewater. 13th edition.
American Water Works Association, Water Pollution Control
Federation, Washington, DC.
American Society for Testing Materials (ASTM). 1973. Annual book
of standards; part 23, water; atmospheric analysis. Philadelphia.
Blackman, W. C., Jr., J. V. Rouse, 6. R. SchllUnger and W. H. Shofer,
Jr. 1973. Mineral pollution 1n the Colorado River Basin.
J.W.P.C.F. 45:1517-1557.
Bull, W. B. and K. M. Scott. 1974. Impact of mining gravel from
urban streambeds 1n the Southwestern United States. Geology
2:171-174.
Caldwell, R. D., R. F. Crosby and M. P. Lockard. 1970. Radioactivity
1n coal mine drainage, p. 439-445. _!". W. C. Relny (ed.), Environ-
mental surveillance 1n the vicinity of nuclear facilities.
Cawood, P. B., R. Thunvlk and L. Y. Nllsson. 1971. Hydrologlc modeling -
an approach to digital simulation. Royal Institute of Technology,
Stockholm, Sweden. Report 3:4a.
Crawford, N. H. 1970. What is simulation? Hydrocomp Simulation
Network Newsletter. Palo Alto, CA.
Crawford, N. H., and R. K. Linsley. 1966. Stanford watershed model IV.
Stanford University, Stanford, CA. Tech. Rep. No. 39.
Ellison, W. D. 1945. Some effects of raindrops and surface-flow on
soil erosion and Infiltration. Trans. Am. Geophy. Union 26(111),
p. 415.
Flaxman, E. M. 1972. The use of suspended sediment load measurements
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Proceedings of Sediment Yield Workshop, Oxford, MS.
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35
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38
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TECHNICAL REPORT DATA
(Please read /attractions on the reverse before completing)
1 REPORT NO.
EPA-680A-75-001*
3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
NONPOINT-SOURCE POLLUTION IN SURFACE WATERS:
Associated Problems and Investigative Techniques
5 REPORT DATE
B. PERFORMING ORGANIZATION CODE
7 AUTHOR1S)
Water and Land Monitoring Branch
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Hater and Land Monitoring Branch
Monitoring Applications Laboratory
National Environmental Research Center
P. O...BOX 15027, Las .Vegas, Nevada 89114
10. PROGRAM ELEMENT NO.
1HA326
11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
Office of Research and Development
U.S. Environmental Protection Agency
Washington, DCC. 20460
13. TYPE OF REPORT AND PERIOD COVERED
Final Task Report 22AEB/002
14. SPONSORING AGENCY CODE
IB. SUPPLEMENTARY NOTES
Task No. 002, ROAP 22AEB
16. ABSTRACT contaminants entering waterways from diffuse or non-distinct points are termed
nonpoint-source pollutants. Principal categories of nonpoint source pollutants in sur-
face waters include sediments, minerals and acids, pesticides, nutrients, organic matter,
heat, microorganisms and radioactive materials. Nonpoint source pollutants ace generated
primarily by such activities as agriculture, silviculture, mining, construction and hydro-
graphic modifications. In terms of volume alone, sediment is the pollutant of greatest
significance, and agricultural cropland is the chief contributor. Various models are
available for predicting rates and effects of nonpoint pollutants in surface water.
Capabilities for predicting sedimentation rates, thermal pollution and mine drainage
are fairly sophisticated, but methods for predicting pollution resulting from pesti-
cides, nutrients, heavy metals, biological contaminants and organic wastes are not well
refined. Techniques for monitoring nonpoint-source pollutants include manual field
sample collection, automated samplers, automatic contact sensors, and to an extent,
remote sensing devices. Parameters which can be automatically monitored in situ with
contact sensors include turbidity, temperature, certain specific ions, specific conduct-
ance, pH and dissolved oxygen. Most other parameters must be measured using laboratory
analytical procedures. Aerial reconnaissance can be used in a cost effective manner to
assess the impact of agriculture, construction mining and silviculture activity on
waterways, but quantitative water quality data cannot be reliably produced with remote
sensing techniques.
7.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Nonpoint source pollution, water pollution
sources, surface water pollution, water
guality monitoring, monitoring techniques,
nonpoint source monitoring, water data
acquisition, contact sensors, remote
sensing
Water pollution,
surface waters,
water quality
0808
1402
8. DISTRIBUTION STATEMENT
Report available from NTIS and from EPA
JERC/Las Vegas
P.O. Box 15027 Las Vegas. NV 89114
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Farm 2220-1 (9-73)
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