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This is to certify that the

dissertation entitled
Land Use and Water Pollution in Puerto Rico
presented by

Sonia I. Arbona

has been accepted towards fulfillment
of the requirements for

degree in Geography

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Ph.D.

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LAND USE AND WATER POLLUTION IN PUERTO RICO

By

Sonia I. Arbona

A Dissertation

Submitted to
Michigan State University
in partial fulfillment of the requirements
for the degree of

Doctor of Philosophy

Department of Geography
1991

ABSTRACT
LAND USE AND WATER POLLUTION IN PUERTO RICO
By

Sonia I. Arbona

In Puerto Rico, previous water quality analyses have indicated that
most surface waterbodies, as well as groundwater, are polluted with both
organic and inorganic substances. Contributions to water quality
deterioration come from point and nonpoint sources. These pose a threat

on a densely populated island.

In Puerto Rico urban and industrial development occurred rapidly
with a lag in the required infrastructure for expansion. Water pollution
has been a by-product of this process and is regarded as the most serious

environmental problem on the island.

This study examines water quality parameters in three hydrological
basins. It attempts to determine how extensive a problem it is and how the

concentration of pollutants compare in different land use situations.

A total of 33 sampling sites distributed among the three watersheds
was chosen. The sampling sites include surface waterbodies and wells
used for potable water supply. Each site was sampled three times during a
six month period. The spatial design of the sampling sites was as specific

as possible so as to differentiate among suspected pollutant sources.

Fifteen water quality parameters were examined. All of the
waterbodies in spatial association with the land uses considered in this
study presented detectable concentrations of the selected water quality

parameters.

Although most of the parameters were detected at concentrations
below standard limits, some of them either classified as toxic substances
and/or priority pollutants, were above standard limits. If these waters
were to be treated for potable supply, it is not certain that the contaminant
substances would be removed. Furthermore, the potential health hazards
are unknown, particularly when pollutant substances occur in

combination.

The quality of the waters in Puerto Rico is under the surveillance of
official monitoring networks. However pollutant monitoring has been
limited mainly to the analyses of heavy metals. Unfortunately we live in an
environment with multiple exposures to contaminant sources and many
different disease potentials are related to water resources. The degree to
which these potentials actually materialize depends on the treatment of
water supplies and sewage, and the distribution of industrial, agricultural,

and urban activities.

Dedicated to my parents
Charles and Carmen Arbona,
for their love and support.

iv

ACKNOWLEDGMENTS

I wish to express my thanks to the Puerto Rico Environmental
Quality Board and to the Puerto Rico Aqueduct and Sewage Authority for
their interest and cooperation in this study. Thanks are due to Santos
Rohena, President of the Environmental Quality Board, to Tomas Rivera,
Director of the Water Quality Area, and to his assistant, Martha Rivera.
The Environmental Quality Board kindly provided laboratory assistance in
the measuring of heavy metals pollution. To the staff of the Puerto Rico
Aqueduct and Sewage Authority (PRASA) regional laboratories in
Humacao, Toa Alta and Mayagiiez I extend my appreciation for their
laboratory services in measuring total and fecal coliform counts.

I am particularly grateful to the Sampling Division of the Water
Quality Program and its chief Reynaldo Matos. David Marrero, Edwin
Martinez and Rodrigo Diaz provided invaluable assistance in the field.

I am indebted to Dr. Osvaldo Rosario from the Department of
Chemistry at the University of Puerto Rico. The support and collaboration
provided at his laboratory allowed me full access to his laboratory in order
to measure for synthetic organic compounds.

I thank the members of my doctoral committee for their support and
encouragement, Dr. Daniel Jacobson, Dr. Gary M. Manson, Dr. Robert N.
Thomas, and especially to Dr. John M. Hunter, my advisor, for his valuable
suggestions and counsel.

TABLE OF CONTENTS

Page
List of Tables .................................................................... vii
List of Figures .................................................................. ix
Introduction ..................................................................... 1
I. Water Pollution ................................................................. 5
II. Water Pollution in Puerto Rico ............................................ 22
III. Methodology and Description of the Study Area ..................... 40
IV. Analysis of Results by Hydrological Basin ............................ 55
V. Analysis of Results by Land Use .......................................... 84
VI. Conclusions and Recommendations .................................... 110
Appendix A. Description of Water Quality Analyses ................ 113
Appendix B. Detected Semi-Volatile Organic
Compounds By Hydrological Basin ...................... 123
Bibliography .............................................................................. 132

10.

11.

LIST OF TABLES

Page
The Most Common Chemicals Used by Local Industries
In Puerto Rico ................................................................. 31
Sampling Stations and Surrounding Land Uses
Cibuco River Basin ........................................................... 47
Sampling Stations and Surrounding Land Uses
Guayanés River Basin ...................................................... 48
Sampling Stations and Surrounding Land Uses -
Yagiiez River Basin ......................................................... 49
Water Quality Standards .................................................. 51
Yagiiez River Basin Stations
Detected Concentrations of Water Parameters .................... 53
Cibuco River Basin
Detected Concentrations of Water Parameters .................... 70
Guayanés River Basin
Detected Concentrations of Water Parameters .................... 77
Maximum Concentrations Detected by Land Use ................ 85
Agriculture-Land Use
Detected Concentrations of Water Parameters .................... 87
Livestock-Land Use
Detected Concentrations of Water Parameters .................... 9o

12.

13.

14.

Industry-Land Use

Detected Concentrations of Water Parameters .................... 92
Commercial-Land Use

Detected Concentrations of Water Parameters .................... 98
Residential

Detected Concentrations of Water Parameters .................... 100

Sewage Treatment Plant
Detected Concentrations of Water Parameters ...................... 104

PPSP’PPP’N!‘

H
P

LISI‘ OF FIGURES

Page
Geographical Location ....................................................... 23
Drainage System ............................................................... 25
Geology ............................................................................. 26
Hydrological Basins of the Study Area .................................. 43
Cibuco River Basin-Sampling Stations ................................. 44
Guayanés River Basin-Sampling Stations ............................ 45
Yagiiez River Basin-Sampling Stations ............................... 46
Yagiiez River Basin-Land Use ............................................ 60
Cibuco River Basin-Land Use .............................................. 72
Guayanés River Basin-Land Use ......................................... 79

81

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INTRODUCTION

The purpose of this study is to develop a reconnaissance survey of
water pollutants and their association with land use in three hydrological
basins in Puerto Rico: Cibuco River watershed, Guayanés River watershed,

and Yagiiez River watershed.

Since water pollution is usually measured against the intended use
of the water, it can have several definitions. In this study we understand
water pollution as excessive concentrations over periods of time of
particular substances sufficient to cause detrimental effects against

biological and human health.

[:In Puerto Rico, water quality analysis has indicated that most
surface and groundwater, are polluted with organic and inorganic
material or substances. Contributions to water quality deterioration come
from many point and non-point sources. Practices at the individual,
community and industrial level can create high risk situations with long
term health implications. These pose a threat to public health on an island
that covers only 3,500 square miles, with an estimated population of 3.2

million, a very densely populated country. 3

In the 1950's Puerto Rico was involved in a program of
industrialization which attempted to convert the island's economy from an
agricultural to an industrial base. Urban and industrial development
occurred rapidly, but a lag arose in the provision of the infrastructure

necessary for a balanced expansion. The distribution of industries reflects

2

the industrialization policies of the government. It covers the whole
spectrum from heavy to light industries. On an island-wide map of point
sources, a band along the coast can be traced where most of the industries
are located. These coastal plains are where most population growth has
occurred, and also where most of the island's underground water

reservoirs are found.

[According to the Puerto Rico Environmental Quality Board, pollution
by pathogens, nutrients and suspended solids were the principal water
quality problems of the island during 1986-87. Non-point sources of
pollution originated mainly from agricultural activities, waste disposal and
wastewaters from communities, and urban surface runoff. Discharges
from municipal sewage treatment plants, as well from industrial
discharges, were responsible for most of the impact from point sources.
Large manufacturing firms have also been known to dispose of their wastes
individually and improperly into surface streams, sinkholes and sanitary
landfills. Toxic wastes in Puerto Rico are mainly generated by electronic,
electrical and chemical companies, and also by the agriculture sector

through the use of pesticides.)

CMoreover, the Puerto Rico Department of Health has reported
gastroenteritis as the most frequent transmissible disease during recent
years. The quality of the potable water served by the official Puerto Rico
Aqueduct and Sewer Authority has been implicated as a possible culprit in
some of the outbreaks. 3

CWith regard to groundwater, which provides nearly 30 per cent of the

total water used island-wide, high concentrations of various volatile

3

organic compounds have been detected, especially in the northern part of
the island. Contamination of groundwater may come from spills, direct
land disposal or by septic tank leakage. The Puerto Rico Environmental
Quality Board has just recently reviewed its water quality standards and

for the first time there are some specific regulations to govern groundwater

quality.

The quality of most of the streams in Puerto Rico is under the
surveillance of an official monitoring network which consists of 57 stations.
However, toxic pollutants monitoring has been limited mainly to the
analyses of heavy metals. Special monitoring for other toxic substances
such as pesticides, volatile organics, and acid/base neutral fractions of

priority pollutants was initiated at some stream stations in 1985.

The sources of dangerous contamination are ubiquitous. Although
the assessment of human health impacts caused by pollution is difficult,
and a cause-effect relationship is not by any means established, the need for

a better assessment of water quality and health implications is imperative.

In this exploratory reconnaissance survey, water from 33 selected
sites in the three hydrological basins was sampled three times during a six-
month period. The sampling sites included waterbodies surrounded by
different land use situations such as industrial activities, sewage treatment
plants, livestock activities, commercial and residential areas, and the main

agricultural areas of sugar cane, pineapple, coffee and plantains.

The sampling sites include surface running waters such as rivers
and creeks, and wells that are currently in use for potable supply. We did

not measure depth, size and volume of water bodies.

4

Laboratory analyses included BOD-5, total and fecal coliforms,
semivolatile organic compounds, ammonia, nitrite, nitrate, total kjeldahl
nitrogen, cyanide, arsenic and the heavy metals mercury, lead, cadmium,

chromium, and nickel.

In general, studies to assess water quality in Puerto Rico have been
conducted on a site-by-site basis with the objective of fulfilling the specific
needs of a particular agency or industry at a given site or area, especially

regarding groundwater quality.

A more complete and comprehensive environmental monitoring
assessment is needed to obtain data showing the pollution and land use
relationship. This study, as a preliminary survey, can provide additional
information for the evaluation and modification of monitoring activities,
including site selection and parameters investigated. Assessment and
reappraisal of monitoring activities is much needed since many
waterbodies can be polluted by toxics, but a lack of monitoring data will
make it impossible to estimate how widespread the problems are, or to

determine whether conditions are getting better or worse.

CHAPTER I

WATER POLLUTION

Environmental pollutants can be divided into three broad categories:
those occuring naturally, those either transformed or concentrated by
living or nonliving systems, and those produced by man's activities. When
a balance is upset by either natural or man-made events, the background
levels of many compounds in the biosphere increase to such an extent that
they pose a threat to many living forms (Greenberg, 1987). Any substance
that is added to the environment at a rate greater than it can be removed
will build up. Water pollution can be defined in a number of ways, but. most
definitions refer to excessive concentrations of particular substances for

sufficient periods of time to cause particular effects.

Water quality is a term associated with the analysis of physical,
chemical and bacteriological parameters. Physical parameters include
color, odor, temperature, solids, turbidity, oil and grease. Chemical
parameters are associated with the organic content of water and include
analysis for organic chemicals, biochemical oxygen demand (BOD),
chemical oxygen demand (COD), total organic carbon (TOC) and total
oxygen demand (TOD). The inorganic chemical parameters include pH,
hardness, chlorines, sulfates, sulfides, heavy metals, nitrogen (organic,
ammonia, nitrite, and nitrate) and phosphorus. Bacteriological
parameters include total coliforms, fecal coliforms, specific pathogens and

viruses.

6

Pollutants are transported in water as dissolved ions and molecules
or on suspended particulate matter. Water soluble pollutants that move
freely are diluted as uncontaminated water mixes with contaminated
water. Concentrations of soluble pollutants, therefore, decrease as distance
from the source of pollution increases. Chemical and biological
degradation reduces the concentration of contaminants, and most water
soluble organic compounds are biologically degraded within a few days or

weeks.

The insoluble pollutants and those that are adsorbed to particulate
matter are moved as suspended particles. Over a long time, total
movement can be extensive and long-distance, if the contaminant is
persistent. Chemicals that persist in the environment for long periods can
be deposited in sediment along streams and in other bodies of water and
accumulate there. The ultimate sink is the ocean floor (Chiras, 1985).

Point Sources and Non-Point Sources

Water quality degradation comes from many sources. Water is an
important pathway‘for pollutants: most will find their way into surface and
underground water after their release into the environment, and others are
directly discharged into waterbodies since water is usually the most

convenient disposal route for many wastes.

Point sources of water pollution are those that discharge pollutants at
discrete locations. Industrial wastes that are discharged directly into

surface waterbodies, or that seep into groundwater from land disposal

7

sites, fall into this category. Point sources occur at specific locations and
are, at least theoretically, easier to detect and control than non-point

sources.

Non-point or areal sources of pollution refer to those substances
which can be introduced into receiving waters from broad areas such as
urban or rural runoff. Whereas municipal and industrial point sources of
pollution are discharged directly to receiving waters, nonpoint sources
must rely on the transport mechanisms of the hydrologic cycle to provide
the means of movement from the land. The pollution of lakes and streams
is the direct result of the interaction between land use activities and the
hydrologic cycle. Runoff from urban areas may contain numerous types of
chemical and microbiological pollutants and the runoff from agricultural
areas contain not only barnyard wastes but also fertilizers and pesticides.
Many of the industrial and agricultural wastes coming into waterbodies
from these sources have proven to be highly toxic. Since these sources of
pollutants are areal and dispersed they are diflicult to detect and to subject
to regulation.

Groundwater and Surface Water Pollution

Groundwater has been generally regarded as safe from
contamination and as requiring minimum treatment before use. In most
cases the pollution must pass through a layer of soil where attenuation of
contaminants occurs. However, if the soil is polluted to such a degree that
its adsorptive retention power is exceeded, then pollutants can be released

to groundwater. Moreover, water movement through limestone may be

8

extremely fast, so that groundwater can be similar to surface water in

relation to contaminants.

In landfills, for example, the largest component of waste is paper,
but substantial food wastes, glass, metals, plastics and liquid wastes are
included. Municipal sites also receive industrial process residues, where
manufacturing wastes are included. Hazardous constituents are often
present in the leachate from these wastes. The leachate can reach surface
waters or percolate to an aquifer (Cyr et al, 1987). Because groundwater
generally moves slowly through an aquifer, it may take years for water
polluted in one location to appear in another. Additionally, once an aquifer
is contaminated the pollutants may remain for centuries. Contaminants in
groundwater may partition between the water and organic matter in soil
particles. Chemicals adhere to the soil particles making removal through
groundwater pumping difficult (Travis and Doty, 1990).

Innumerable waste materials and natural and man-made products,
with the potential to contaminate water sources are stored or disposed of on,
or beneath the land surface. For control of groundwater contamination,
effluent limits apply to a broad range of activities, such as limits on types of
materials disposed of in sanitary landfills, limits on specific contaminants
injected into an aquifer by mean of a disposal well and pollutant discharge
limitations for surface impoundments.

Industrial waste water impoundments are a more serious source of
groundwater contamination for their potential of leaking hazardous
substances. Liners are no guarantee against eventual leakage of

contaminants. They can fail mechanically or can be physically altered by

9

the contained wastes. Most of the substances found in industrial wastes
are complex and are not normally included in routine analysis of water
supplies. Alternatives to industrial impoundments are available, such as
above ground tanks, and digestion for sludges or wastes with high organic

content, but these can have a major economic impact on industries.

Surface waters such as rivers, lakes and ponds can be easier to
pollute than groundwater. Pollutants can be disharged directly into the
surface waterbody or may be washed into streams and lakes by the action of

rain.

Rural non-point sources that contribute to the pollution of surface
water include runoff from land where animal manure or sewage waste has
occurred, or runoff from lands utilized by grazing animals or where
intensive use of pesticides and fertilizers have been used without regard to
their pollution potential. Particularly, feedlots may be located where
natural drainage aids in the transport of wastes to the nearest streams.
Thus, transport of pollutants to nearby surface waterbodies can be effective

via surface runoff.

Chemical and Mimbiological Pollution

The effect of pollution on the receiving waterbodies depends on the
type and concentration of pollutants. The contamination of water by
physical pollution, and by organic and inorganic chemicals has been

identified as the most important aspect of water pollution but, in some

10

areas, microbiological contamination of water can still present a serious

health hazard.

M' 1.1.121“.

[One of the greatest potential health hazards associated with water
supply is the possibility that it could become a vehicle for the spread of a
waterborne infectious disease. This is particularly true in less developed
countries without an adequate water supply. Although widespread
disinfection of water supplies has considerably reduced this problem in
developed countries, waterborne diseases such as cholera and hepatitis are
a present health problem to many in developing countries. The basic
problem is a lack of, or inadequate water treament and supply facilities.
However, countries with an adequate water infrastructure may still
experience waterborne disease outbreaks as a result of inadequacies in the

system at the treatment stage or during delivery (Page, 1987).

Pathogenic organisms are found in the stools of populations of who
are suffering from acute disease. The release of fecal pollution into water
can produce outbreaks of gastro-intestinal illnesses which are
characterized by diarrhoea, abdominal cramps, vomiting, acute distress
and fever. Sewage treatment plants are usually very effective in reducing
the introduction of human and animal wastes into water resources.
However, as the water supply sources become more polluted they require
more extended and consistent treatment, thus the risk of an error becomes
greater both with the increased complexity of the treatment and the
pollution load being treated, all of which may adversely affect the required

11

continuity of high level of performance. In addition, untreated sewage can
reach underground and surface water through leaking sewers, cesspits
and septic tanks. Surface waters, as well as underground waters, may be

polluted by pathogenic bacteria, viruses and protozoan parasites.

When community outbreaks occur, in all countries, large number of
cases receive only home treatment. Even countries with relatively elaborate
reporting systems admit that their data are incomplete and biased. It is
commonly estimated that the reported outbreaks of waterborne diseases
represent about 10 per cent of the true number; the remainder are

unreported (Page, 1987).

Bacterial diseases can be effectively controlled by water treatment.
But measuring the actual level of each pathogenic organism is costly and
time consuming, therefore water quality control programs routinely
monitor coliform bacteria levels in water samples to obtain an indication of
how much fecal contamination has occurred. The assumption is that the
higher the coliform count, the more likely it is that the water contains some
pathogenic agent from fecal contamination. However, there are some
pathogenic strains of the indicator bacteria, Escherichia coli, which
apparently grow in water in tropical environments and may become part of
the natural flora thus rendering the coliform parameter inappropriate as

an indicator of recent fecal contamination.(Hazen et al, 1987).

Bifidobacterium adolescetis has been suggested as an alternative
indicator in tropical environments. It is also one of the dominant
anaerobes in the gut of humans and is incapable of surviving in an

oxygenated environment (Mara and Oragui, 1985). These characteristics

12

make it a good indicator. It should be noted that while the World Health
Organization (WHO) has established international guidelines for coliform

counts, these were stated only as general rules.

The use of indicator bacteria does not guarantee a perfect treatment,
since the possibility remains for waterborne bacterial illness caused by low
levels of virulent pathogens. Viruses can retain the ability to cause human
infections. They have been found to survive longer in natural waters and
during water treament than bacterial pathogens and indicator bacteria.
The extent of illness caused by waterborne viral infection is unknown.
Gastroenteritis, a common waterborne disease may be caused by a viral
infection. Poliovirus and infectious hepatitis A are among the viruses most
often identified in water and that can cause episodes of illnesses. in a

population whose water sources are sufficiently contaminated (Page, 1987).

A number of protozoa can be transmitted to humans through water
(Raidt and Acierno, 1985). Current chlorination procedures do not destroy
Giardia lamblia, a pathogenic protozoa that causes giardiasis and that may
be present in drinking water supplies which meet the coliform standard.
The symptoms of giardiasis may involve diarrhea, loss of apetite,
dehydration, cramps and in some cases vomiting. The cysts of Giardia
lamblia and other protozoa can be removed by sedimentation and filtration
through sand, but in order to be effective in removing protozoa from water
the filters must receive proper maintenance. The respective use of
coagulation, sedimentation and filtration in water treatment plants will
vary with the number of customers of the water supply system in order to be
effective. Giardia lamblia may be responsible for cases of gastroenteritis for

which no known etiological agent can be identified.

13

Cl .121“.

Since the Second World War a vast number of organic chemicals
have been produced and introduced into the environment. Synthetic
organic compounds constitute a major type of pollutant and can be found in
urban or rural land uses from point or non-point sources. Usually organic
chemicals are found at very low concentrations in water. Many are non-
biodegradable or are so slowly degraded that they persist in the ecosystem
(Greenberg, 1987).

Industries continue to produce large amounts of synthetic organic
materials. Many of these substances do not occur naturally and the end
uses of many products tend to disperse them widely in the environment.
Production and waste disposal sites also can release synthetic organic
chemicals and their decomposition products into the atmosphere and

hydrosphere.

The potential for water pollution by chemicals depends upon factors
such as direct or indirect release into water, solubility, vapor pressure, and
use. Following emission, chemicals may be chemically degraded in the
environment or they may have volatility characteristics that cause their
release from water. The rates of degradation may differ. The
accumulation of materials in systems and organisms is primarily a
function of water and lipid solubility, sedimentation, and binding to
inorganic or organic substances. The toxicity of many industrial chemicals

is partly known in humans largely because of potential exposure of the

14

labor force, but the effects, especially chronic ones, are poorly known for the
vast majority of organisms (Anderson and Abdelghani, 1985).

The Federal Water Pollution Control Act Amendments of 1972 (P.L.
92-500) required the US. Environmental Protection Agency to develop a
comprehensive program to improve the quality of the waterbodies in the
United States. Section 307(a) mandated publication of a list of toxic
pollutants for which effluent standards were being established. These
substances were selected on the basis of their known occurrence in
effluents, their presence in drinking water or fish, their known. or
suspected cacinogenic, mutagenic, or teratogenic properties, their
likelihood of human exposure, their persistence in the aquatic food web,
their propensity for bioaccumulation, and their toxicity to aquatic
organisms and those (ineluding humans) which might feed on such
organisms (Middlediteh et al, 1981). The list includes 114 organic priority
pollutants. In addition, 13 metals (antimony, arsenic, berylium, cadmium,
chromium, copper, lead, mercury, nickel, selenium, silver, thallium, and
zinc) along with three miscellaneous categories; cyanides, asbestos and
phenols, complete the list of 129 priority pollutant species (Code of Federal
Regulations, 1979). Many which have been created since then have not yet
been added to the official EPA list.

Most of the organic chemicals that cause health concerns are man-
made. While acute effects of exposure to organics are known, it is
generally assumed that the long term effects of the ingestion of small
quantities for very long periods of time would not necessarily resemble the
acute toxic effects of a substance (Page, 1987).

15

The causes of outbreaks of infectious disease are better understood
than the possible chronic effects of chemical contamination. The acute
effects of organics are known from industrial exposures, but most synthetic
organics in water are found at low concentrations and may be ingested over
many years. Little is known about the long term effects of trace levels.
There is virtually no information on factors such as nutrition and the
influence it may have on the response to a chemical insult. The effect
might be just as great as that caused from a change in the dose of the

chemical exposure (Lioy, 1990).

It is known that some chemicals can be stored in fat cells where they
can accumulate faster than they are degraded or eliminated, hence their
potential for disease causation. These substances constitute 90 per cent of
those listed in United States as potencial carcinogens. But cancer is not the
only threat; nervous system disorders and genetic damage are among other
possible health impacts. There is also the potential for synergisms among
the mixtures of many different organic chemicals that may simultaneously

be present and for which there is only rudimentary knowledge.

The problem is complicated because new organic chemical
compounds are being created and introduced into the environment. The
processes by which they reach water sources vary. Some, like the
pesticides, are intentionally released into the environment. Unintentional
releases occur during accidents. But they are also released from industrial

as well as domestic landfills and their storage and distribution facilities.

Domestic sewage and treated effluents are, in principle, of a nature

that the contaminants they contain can be absorbed by the stream without

16

causing serious long term damage. However, few municipal sewages are
strictly domestic. Most contain some industrial waste and virtually all
contain evidence of the wide array of chemical products used in the modern

home.

Toxic chemicals entering sewage disposal plants, which use
biological degradation systems, often poison the bacteria, the essential
biological catalyst of the system, and lead to failure. This results in
partially treated or untreated municipal sewage being discharged into
streams causing great environmental damage from the high biological
oxygen demand of sewage and the consequent low dissolved oxygen content

in water (Marrack, 1981).

Among different technologies of water treatment, activated carbon
has been found effective in removing many organic chemicals. However
the cost of operation makes it too expensive to be widely used. Moreover,
commonly used purification systems actually could increase the levels of
toxic chemicals found in water supplied to consumers by the addition of
chlorine for disinfection purposes. The organic content in the water reacts
with chlorine creating a multitude of toxic and carcinogenic organic
chlorination by-products, such as trihalomethanes, the most widely

identified toxic organic chemicals in water supplies (Canter, 1985).

Metals are inorganic chemical compounds, and some of them have
essential physiological roles. But there are others having similar chemical
characteristics that may also interact with biological tissues, possibly
resulting in toxic efi'ects when present at sufficient concentrations. These

elements are called heavy metals because they are metals or metalloids that

17

have higher atomic weights than do the essential elemental metals

(Mailman, 1980).

While there is some unavoidable mobilization of heavy metals which
results from leaching of ores by rain or running water, more important
sources of heavy metals pollution are industrial discharges, urban runoff,
mining, soil erosion, sewage effluents, and even air pollution fallout. Solid
wastes in municipal dumps also contain metals, and if the dump sites are
placed in the wrong hydrogeologic environment, rain water can leach out
the metals, along with a variety of other pollutants that can reach surface

and underground waterbodies.

Because of their wide distribution in nature and their extensive
industrial uses toxic levels of heavy metals are now found increasingly in
human food, in their water supplies and as suspended particulate matter
in the atmosphere. Metals discharged in industrial wastes have been
reduced, but the legacy of past excessive discharges may remain in many
river bottoms and could reappear when stream erosion patterns change or

in any situation that disturbs the sediments at the bottom.

Since heavy metals are elements, they cannot be degraded once they
are released into the environment. This same characteristic prevents them
from being eliminated from tissues by metabolic degradation and provides
for the potential accumulation in the body, leading to chronic effects. Once
in the body the rate and pathway of metal excretion vary from one metal to
the other. The biological half life in human beings and other organisms not
only varies with the metal but also with the type of body tissue involved
(Clarkson, 1979).

18

The consumption of aquatic organisms from contaminated waters
can also have an effect on human health. The term bioaccumulation refers
to the accumulation of a chemical within an organism due to the ingestion
of contaminated food as well as water. Feeding is an important source for
bioaccumulation of many toxic heavy metals. The process of
bioaccumulation may result in biomagnification, that is, an increase in

concentration of chemicals within organisms.

Accumulation in tissues does not necessarily imply the occurrence of
a toxic effect. Storage depots may form in body tissues. The long term
effects of this retention over a human life span is not yet fully understood.
Organ storage can prevent the acute toxic effects of the metal, but it is not

clear to what extent it is without hazards over long periods of time.

Heavy metals and organic forms of nitrogen are among the major
groundwater contaminants. Nitrogen is present in the atmosphere,
hydrosphere and biosphere. All forms of nitrogen - nitrate, nitrite,

ammonia and organic - are components of the nitrogen cycle.

Organic nitrogen includes such natural materials as proteins and
peptides, nucleic acids and urea, and numerous synthetic organic
materials (Standard Methods, 1985). Nitrogen in reduced or organic forms
is converted by soil bacteria into nitrite and nitrate. Nitrogen occurs in
water as nitrite (N02), nitrate (N03) and ammonia (NH4). Some other
forms such as cyanide (CN) may occur in water affected by waste disposal.
The nitrites and organic species are generally considered to be indicators of
pollution through disposal of sewage or organic waste. The presence of

nitrate or ammonia might be indicative of such pollution also, but generally

d1

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19

the pollution would have occurred at a site or time substantially removed
from the sampling point (Hem, 1985). Nitrates may be reduced to nitrites in
the gastrointestinal tract. Nitrites in turn, combine with the hemoglobin in
red blood corpuscles and form metahemoglobin, which has a reduced
oxygen-carrying capacity. Nitrites can be dangerous and even fatal in
infants younger than three months (Chiras, 1985). The production and use
of synthetic fertilizers such as ammonia and other nitrogen compounds
may have increased the presence of nitrate in rivers and groundwater.
Farm animals in confinememnt can produce considerable. concentrations
of nitrogenous organic waste. Drainage from nearby barnyards or septic

tanks and cesspools can also be implicated.

With regard to chemical pollutants more research is needed to decide
what can be accepted as a safe concentration. Many chemicals have been
pronounced safe on the basis of short-term tests whereas subsequent
ecological experience has shown that they can have long-term adverse
effects. Another problem is to discover how many other chemicals, about
which relatively litte is known, are present in the environment and to

determine the means to control them.

The majority of the studies which provide information on which
decisions are made are those using animals. Extrapolations from
experimental animals to people have many limitations (Calabrese, 1987).
Sometimes data on the direct effects of a compound on humans are
available as a result of pharmaceutical and medical research or from
industrial toxicology, epidemiology or poisonings, but this type of
information is usually limited. A means for measuring the synergistic and

antagonistic effects of chemicals is necessary, as well as better case control

20

data to assess the exposure of the populations to other, that is, non-water
related toxic treats.

Accurate assessment of human health impacts caused by pollution is
extremely difficult. Overall, however, available scientific evidence
continues to substantiate the link between toxics in water and serious

public health concerns.

Regarding pollutants and land use, previous studies have found the
following associations: a) gross organic pesticide contamination with
agricultural, forest and horticultural land uses; b) gross light chlorinated
hydrocarbon pollution and industrial and commercial areas; and c) gross
heavy metal contamination with industrial, commercial and agricultural

areas (Greenberg et al, 1982).

Heavy chlorinated hydrocarbons, which include pesticides, are noted
for their low volatility and high persistence in the environment. The light
chlorinated hydrocarbons are more volatile and less persistent in the
environment than the pesticides. These substances are commonly used in
industrial products including industrial solvents, gasoline additives,
disinfectants and cleansing agents. Heavy metals may find their way into
waterbodies from the natural weathering of rock formations and soil, but
they may find their way into waterbodies from industrial activities, urban

runoff, municipal wastewater treatment, or abandoned mines.

The Nationwide Urban Runoff Program, developed by the US.
Environmental Protection Agency as a program to obtain data on control of
urban water quality and its impact on receiving waters, has confirmed that

pollution problems such as coliform bacteria, nutrients or heavy metals

21

result from urban runoff. But agricultural activities, especially tillage
practices and animal waste management, are the main contributors of

non-point sources pollution in both lakes and rivers (Humerik et a1, 1987).

Many different diseases are potentially related to water resources, as
it has been discussed, and the degree to which these potentials actually
materialize depends largely on matters such as the treatment of water
supplies, methods of agricultural and industrial production, and

monitoring and implementation of control strategies.

CHAPTER II

WATER POLLUTION IN PUERTO RICO

The island of Puerto Rico is located about 18 degrees north latitude
and 66 degrees west longitude. Roughly rectangular in shape, it is 100
miles east-west and about 35 miles north-south (Fig.1). Puerto Rico is one
of the most densely populated countries in the world with about 800 persons
per square mile. Approximately 43 percent of the population is
concentrated within 15 miles of San Juan and 12 percent within 5 miles of
Ponce, the second major urban center outside the San Juan metropolitan

area.

Although small in size the island of Puerto Rico has a diverse
physical environment. The diversity is caused mostly by the topographic
relief and its effect on rainfall distribution more than by any other factor. A
complex central ridge system averages 2,800 feet, with a maximum altitude
of 4,400 feet, and forms a barrier to the northeast trade winds. As a result,
most of the south coast averages less than 45 inches of rainfall per year,

while the northern part of the island averages about 80 inches per year.

Even though the mean annual rainfall seems high compared to that
of temperate climates, much of the rain occurs in short intense showers
and is lost to evotranspiration. Of the 75 inches that the island receives in

an average year, 45 inches are lost to

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24

evapotranspiration, 27 inches are accounted as streamflow and about 3

inches is ground-water discharge (U.S.G.S., 1987).

The principal rivers flow from the central ridge to the sea (Fig.2).
There are approximately 100 streams and rivers contained in 33 principal
basins. No natural lakes exist in Puerto Rico, but 28 reservoirs and ponds

have been constructed for water supply, irrigation and hydroelectric power

(U.S.G.S., 1987).

The central core of Puerto Rico consists primarily of volcanic and
intrusive rocks of Late Cretaceous and early Tertiary age. The central core
is flanked in the north and south by clastic sediments and limestones of
Oligocene and Miocene age (Fig. 3). Along the north coast, the limestone
has been subjected to extensive solutional activity which has resulted in the

formation of a mature karst topography.

The aquifer system is one of the prime sources of water supply for
industrial, agricultural, and domestic use. According to information from
the United States Geological Survey (USGS), groundwater constitutes
nearly 30 percent of the total water used in Puerto Rico (U.S.G.S., 1985).
Irrigation is the main use followed by public water supply and industry, the
main users being the pharmaceuticals and electronics plants. The coastal
plains, especially the northern one, have the great majority of the
population and are also where most of the urban and industrial growth

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27

Starting in the 1950's Puerto Rico was involved in a program of
industrialization which attempted to convert the island's economy from an
agricultural to an industrial base (Parrilla, 1977). During the first years of
the industrialization effort, firms from the United States were attracted to
Puerto Rico by lower labor and production costs, and later by tax exemption.
In those early years, emphasis was placed upon labor-intensive industries
such as food processing and related activities including rum distilling,
textiles, apparel and tobacco products. The manufacture of cement, bricks,
tiles, ceramics and glass was also important. These industries were
established in the principal cities, especially in San Juan, which not only
created an industrial concentration in and around San Juan, but also

promoted a migration from the countryside to the capital city.

With rapid growth, the provision of facilities and necessary services
for the new city inhabitants became difficult. In an attempt to divert the
flow of population toward the capital, a program of industrial
decentralization was adopted. The program was based on providing better
incentives for those industries that were to be located in less developed

municipalities.

Later on, in the mid 1960's the establishment of chemical and
petrochemical activities exhibited rapid expansion. These industries are
more capital-intensive and require less labor, but more specialized and
capable of operating complex machinery of high productivity. The
production of alcoholic beverages, electronic and scientific devices, metal

products and glass also increased considerably (Cruz, 1988).

28

[With a time-lag necessary for infrastructure support, urban
development also rapidly expanded. In a period of about thirty years
Puerto Rico has changed from being a predominantly agrarian society to
one of services and manufacturing. The most evident results of this impact
have been a deteriorated rural landscape, some industrial nuclei, and a
highly comercialized urban landscape. Water pollution has become a by-
product of this process and constitutes the most serious environmental

problem of the island.

According to the Puerto Rico Environmental Quality Board the
presence of high concentrations of fecal coliforms and streptococci bacteria
is the principal water quality problem of surface water bodies in Puerto
Rico. Available data on river water quality show the following violations:
(1) dissolved oxygen, 75 percent of rivers violate current standards; (2)
biochemical oxygen demand, 64 percent of rivers violate current standards;
and (3) for total coliforms, 95 percent of rivers violate current standards

(Puerto Rico Environmental Quality Board, 1984-85).

There are 526 administratively listed polluting entities that generate
toxic substances on the island, of which 76 are sewage treatment plants.
Coliform violations are attributed to a large rural population lacking
adequate waste disposal, inadequate treatment plants and inadequate
disinfection together with commercial runoff from dairy farms and pasture
lands. About 90 percent of the biochemical oxygen demand to water quality
standards are the result of discharges from industries and municipal

sewage treatment plants. 3

29

The Puerto Rico Aqueduct and Sewer Authority (PRASA) created in
1945 is the agency responsible for treatment and distribution of potable
water. In addition this agency is responsible for the operation and
maintenance of sanitary wastewater (sewage) treatment plants. Currently
PRASA has serious problems with the sewage treatment plants. From a
total of 114 treatment plants 85 were included in a Federal Court Order
issued in 1978 in which the United States Supreme Court assumed
jurisdiction over those treatment facilities that were not properly operated
by PRASA. These plants were included in the Order because they did not
comply with the National Pollutants Discharge Elimination System
(NPDES) permits. As a result of substandard sewage treatment plants, the
waterbodies received discharges that seriously reduced the water quality,
thus causing a threat to health in the potable water served by PRASA.
Today, 13 years later, 54 of the 114 treatment plants remain under the
Federal Court Order. Eight of these regularly receive discharges that
exceed their processing capacity thus resulting in overflow releases of raw

sewage into the environment.

CFiltrations from these plants are also a threat to groundwater and
bacterial contamination has been detected in groundwater. In a report by
the US. Geological Survey in 1982 it is indicated that four wells in the
northern aquifer were contaminated with fecal bacteria from 40 up to 100
percent of the time. According to EPA officials on the island,
contamination of rivers with schistosomes, the disease agent of
schistosomiasis or bilharzia, may also be related with fecal wastes that
reach the bodies of water either by direct contamination or through

inadequate filtrations and treatment.)

30

(The Puerto Rico Department of Health has reported gastroenteritis as
the most frequent transmissible disease during recent years. The number
of reported cases in 1988 was 61,321 and in 1989 69,775 were reported.
Bacterial contamination of water was suspected as the source of disease

transmission;

Giardiasis has been mentioned as another posible culprit in the
gastroenteritis cases. However, the position of PRASA officials is that
Giardia lamblia is resistant to chlorination and therefore its presence in
potable water supplies does not imply an inefficient filtration system.
However, the cysts of this protozoan can be removed through the process of
coagulation and sedimentation at the treatment plant, provided the system

is working properly at the volume or capacity for which it was designed.

But bacterial contamination is not the only problem with the water in
Puerto Rico. Most large manufacturing firms had been known to dispose
their wastes individually and inadequately in surface streams, sinkholes
and sanitary landfills. In general, little control exists over the treatment

and discharge of industrial wastes.

Cl‘he Puerto Rico Environmental Quality Board (PREQB) reports that p

more than 110 chemical sustances are handled in several industries

‘,,_~.— -—-——-4 -—-—‘m.~.—m,..

operating on the island. The most commonly used chemicals are presented
in Table 1. In 1988, a total of 510 major industrial concentrations were
distributed as follows: 76 in Humacao, 71 in San Juan, 69 in Arecibo, 68 in
Ponce, 58 in Carolina, 55 in Guayama, 40 in Aguadilla, 39 in Orocovis and
34 in Mayagiiez. All of these industries, with the exception of the ones in

Orocovis, were located in coastal areas (PREQB, personal communication).

31

 

 

 

Table 1. The Most Common Chemicals Used
By Local Industries in Puerto Rico

Chemicals Uses Hazards

Methanol Highly flammable liquid used Severe exposure can cause dizzi-
in solvents, cleaners and fuels. ness, loss of sight, unconscious-

ness, death. Absorbed through
skin.

Toluene Solvent for perfumes, medi- Explosive and flammable.
cines, explosives, dyes, deter- Toxic if ingested, inhaled or
gents and aviation fuels. touched.

Dichlorome- Industrial solvent and paint Carcinogen

thane stripper; used in aerosols and
pesticides, also in films.

Acetone In paint, varnish and lacquer; Dangerous fire hazard that is
solvent for cement in the moderately toxic; irritates eyes
leather and rubber industries. and nervous system.

Freon 113 Common solvent used for Depletes ozone layer.
electronic components;
refrigerant.

Carbon In rayon, cellophane, Highly flammable; toxic even by

Disulfide carbon tetrachloride. touch; attacks nervous system.

Acetonitrile Solvent; also used in organic Cyanide poison that attacks the
synthesis. nervous system, irritates skin

and eyes. ‘

Benzene Petroleum by-product; solvent; Flammable, toxic carcinogen;
in detergents and nylon. poisonous if inhaled or

absorbed through skin.

Cyclohexane Used in making nylon, glass Fire hazard; moderately toxic

1,1,1-trichlo-
roethanc

 

substitutes and solid fuels.

Solvent for cleaning precision
instruments; also in pesticides
and textiles.

 

with pungent odor.

Severe eye irritant, but mode-
rate irritant if absorbed through
skin or inhaled, large dose can
cause cardiac arrest.

 

Source: U.S. Environmental Protection Agency

 

32

Toxic wastes in Puerto Rico are mainly generated by oil refineries,

—.—..
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petrochemicals, electronic, electrical, and chemical companies, medical

,.. A...” —a.

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Moreover, although small scale agnculture has been almost eliminated

from the island, the remaining commercial agriculture uses a wide array

mm-‘u‘ can. ~~.... ,.

of pesticides. Puerto Rico' 3 industries produce and use chemical solvents,
many of the polychlorinated type. In the electric and electronic industries
these solvents are used, like mercury, as well as other heavy metals in
electro-plating. #7

In the early years of industrialization, it was a general practice to
dump industrial wastes in sanitary landfills. These were not designed to
meet the conditions necessary to receive that type of waste. The disposal of
industrial wastes in this manner is now prohibited, but toxic substances

remain buried under tons of sanitary landfill, and illegal dumping of

industrial waste is still in practice.

In fact any sanitary landfill on the island may be suspected of
containing toxic wastes. Currently the Environmental Quality Board has a
list of 169 sites where it is suspected or known that toxics have been
dumped, and 74 of these are sanitary landfills. It is also a matter of
concern that out of 68 municipal landfills only two are working adequately
according to PREQB regulations. The dumps are mostly located on highly
permeable soils that allow contamination to spread by seepage and

drainage far beyond the landfills.

While in 1987 45,000 metric tons of toxic wastes were generated on the
island, the EPA projects that for 1993 this number will increase to 112,000

33

metric tons. Of the total toxic wastes generated in Puerto Rico, 50 percent
are exported to the United States for disposal. The remaining 50 percent
are eliminated by local industries (mainly through incineration), or they
are inadequately disposed of in sanitary landfills, waterbodies, open
terrain, or through the sewage system. PROTECO (Proteccion Técnica
Ecologica), a private company that used to receive, treat, store and dispose
of hazardous materials, failed to meet EPA requirements to operate a
facility for such purposes and had its operations banned by the EPA in the
mid-1980's. Another private firm, the Safety Kleen Envirosystems Co. in

Manati, has permission to operate but this firm disposes of solvents only.

The federal government has designated nine sites in Puerto Rico on
the Superfund National Priority List. This is an inventory of contaminated
sites that represent an imminent threat to human health and the
environment. The cost of cleaning up a contaminated site can vary
depending on the contamination and other environmental factors. The
Superfund created in the 1980's is a federal fund that taxes the main
generators of toxic waste with the objective of creating a fund for cleaning
up the sites where no culprit has been identified, or specific liability

established (Kimbrough, 1990).
The Superfund sites in Puerto Rico include:

1) The Barceloneta landfill which accepts municipal and
industrial waste. The site is underlain by permeable
limestone formations and waste has been placed in sink
holes. There is no natural or artificial barrier to prevent

the migration of contamination.

2)

3)

4)

34

The Juncos landfill where thermometers containing mercury
from the pharmaceutical company Becton Dickinson were
dumped. Leachate from the fill zone enters a highly wet area
and drains toward an artificial channel that is utilized for
agricultural watering. Preliminary studies have indicated
that soil and air may contain higher than background
concentrations of mercury. Several streams flow through the
landfill into the Gurabo River, which drains into Lake Lofza, a
reservoir that supplies drinking water for the San Juan

metropolitan area.

Public supply wells at Guayama contaminated with
tetrachloroethylene, trichloroethylene and other waste
chemicals detected by the U.S. geological Survey during a
survey of public water wells. Solvents were discharged
through the drainage system into lagoons and seeped into the
soil. Four out of five wells show contamination and are closed,
the fith one, which is yet to show contamination, is still open.
The firms Phillips Petroleum, Chevron and American Home
Products have been identified as responsible for the

contamination.

Vega Alta public supply wells are contaminated with

volatile organic compounds. The sources of contamination
have been identified as General Electric del Caribe, The West
Company, Motorola, Harman Automotive, Teledyne
Packaging, and the Puerto Rico Industrial Development

Company.

5)

6)

7)

8)

35

Wells in Arecibo are contaminated with vinyl chloride, TCE
and other solvents. The source of contamination may be a

closed phtalic anhydride manufacturing facility, a subsidiary
of Hooker Chemical and Plastic Corp.

The General Electric Company Wiring Devices site in Juana
Dfaz is contaminated. On the property is an inactive open
dump for off-specification products. Contaminants can
further erode in this dump, which is uncovered, into
adjacent agricultural land. The site is also located in a
residential area. Testing by the company for the PREQB

has found mercury in the open dump.

Frontera Creek in Humacao is a small creek that receives
industrial waste discharges including mercury pesticides.
Adjacent to the creek are two large fresh-water lagoons which
are directly connected to the creek. There is concern that
contaminants will enter the aquatic food chain. Local
residents use the lagoons for fishing and recreation.
Finfish and shellfish trapped in the lagoons are significant in
the local diet. Revlon has been identified as the responsible

party.

RCA del Caribe in Barceloneta manufactures aperture masks
for television picture tubes. The process generates wastes
containing chromium, selenium, and iron which were
discharged into four holding lagoons. Soluble limestone
formations below the site subsequently developed sink holes

36

which then resulted in the subterranean discharge of the
waste contents of the holding lagoons. Public supply wells
serving a population of 12,000 people are located within 1.5

miles of the site.

9) At the Upjohn site in Barceloneta approximately 15,000
gallons of a mixture containing 65 percent carbon tetrachloride
and 35 percent acetonitrile leaked from a buried tank into the
soil and limestone groundwater. UpJohn conducted remedial
measures at the site which removed large areas of
contamination. However, concern exists as to whether the
total extent of the pollution plume has been delineated. EPA
requires UpJohn to sample downgradient private water supply

wells to be sure that no one is drinking contaminated water.

It is expected that another eight sites will be added to the list, and, in
addition, another 140 sites are designated with the potential to be included
(Puerto Rico Environmental Quality Board, personal communication).
This represents a ratio of one hazardous site for every 22 square miles. No
cleanup has begun yet on any of the Superfund sites with the exception of
the UpJohn site. Environmental officials say that cleaning up all the
contaminated sites in Puerto Rico will cost at least 5 billion dollars. Under
the Superfund law, federal authorities will pay 90 percent and the state 10
percent of the cost of cleaning up sites on the national priority list.
However, since the EPA has identified the parties reponsible for eight of the
island's nine hazardous waste sites they will be the ones required to cover

the cost of the clean ups.

37

The quality of the streams in Puerto Rico is under the surveillance of
a water quality monitoring network which consists of 57 stations. Samples
are collected and analyzed by the United States Geological Survey under a
cooperative agreement with the government of Puerto Rico. Through this
network one fifth of the streams are monitored, and 14 percent of these have

been detected with toxic levels that excede federal and state regulations.

The monitoring network includes analysis for some pesticides at a
selected number of stations. During a period from 1982 to 1985, diazinon,
lindane, malathion and parathion were found exceeding their standards.
Diazinon was the pesticide most commonly found. It was detected at 23 out

of 28 stations tested for pesticides.

The stream quality monitoring also includes analyses for some heavy
metals. The evaluation of the data revealed that several stations exceeded
the maximum concentration allowed in Puerto Rico's Water Quality
Standards Regulations for cadmium, copper, mercury and silver (U.S.
Geological Survey, 1985).

Some of the primary pollutants mentioned were detected in effluents
from industrial and municipal discharges to different streams. In each
case, either the NPDES permit effluent limitations or water quality

standards were exceeded at the point of discharge.

Of the 28 reservoirs only 6 are monitored and sampled on a regular
basis by the U.S. Geological Survey. Most of the lakes present
eutrophication problems caused by nutrient loads proceeding from point
sources, like sewage treatment plants, and non-point sources such as

livestock enterprises and other agricultural related activities.

38

Because of its use as a public water supply, groundwater has
acquired great importance. It is suspected that the main pollution source
of the aquifers in these areas has been the practice of industrial waste
disposal directly into sinkholes. In the last eight years 33 contaminated
wells, about 11 percent of Puerto Rico's public wells, have been closed by the
Health Department. The most recent episode occured when the
contamination of at least five wells was noticed in June of 1989, when the
Health Department found concentrations of nitrates fluctuating between
0.30 mg/l and 16.9 mg/l in the wells. The wells supplied 1.3 million gallons
of water daily for the Manatf area.

Specific regulations governing groundwater pollution and
discharges to groundwater will be enforced by the PREQB in 1990, after the
new regulations receive the final aproval. Until now the Puerto Rico
Environmental Quality Board attempted to prevent groundwater pollution
through its general regulatory powers.

Before 1970 there were no regulations strong enough to protect the
environment in Puerto Rico or in the United States. However toxic
substances were handled long before 1970. In Puerto Rico no government
agency is solely responsible for the administration and management of the
waters. Six different agencies are involved: the Puerto Rico Planning
Board, the Puerto Rico Environmental Quality Board, Puerto Rico Aqueduct
and Sewer Authority, the Puerto Rico Department of Health, the United
States Geological Survey, and the United States Environmental Protection
Agency. The analysis of the roles of these agencies indicates that there are
areas of overlapping reponsibilities and that greater efforts of coordination

are needed. So far, no local or federal agency has undertaken a

39

comprehensive study of the island's water supplies particularly regarding
their quality. Furthermore, no comprehensive epidemiological study of
health risks has been made. The field study that follows is the first attempt
to examine the relationship between water quality and geographic patterns
of land use. The scale of investigation is modest but can point the way to a
better understanding of environmental relationships under pressure of

modern industrialization and urbanization.

CHAPTER III

METHODOLOGY AND DESCRIPTION OF THE STUDY AREA

This study examines water quality parameters in three hydrological
basins. It attempts to determine how extensive a problem water pollution is
and how the concentrations of pollutants compare under different
conditions of land uses The selection of the basins is basedon the presence
of land uses considered as predominant on the island, such as commercial,
industrial (manufacturing, chemicals, electronics), residential,
agricultural crops (sugarcane, coffee, pineapple, plantains), livestock, and

specific point sources of pollution like sewage treatment plants.

In Puerto Rico, water quality analyses have indicated that most
surface waterbodies, as well as groundwater, are polluted with both
organic and inorganic substances (Puerto Rico Environmental Quality
Board, 1988). Contributions to water quality deterioration come from point
and nonpoint sources. These pose a threat on a densely populated island
that covers only 3,421 square miles with an estimated population of 3.2

million.

This study addresses the following postulated relationship:
primarily that the presence of pollutants in waterbodies is recognizably
associated with geographical patterns of land use.

41

Related considerations derived fiom the over-arching postulate are:

(1)

(2)

(3)

(4)

(5)

(6)

(7)

The presence of pesticides in waterbodies is associated
with runoff from agricultural crop production activities,

i.e. sugarcane, coffee, plantains.

The presence of nitrogenous waste in waterbodies is

associated with runoff from livestock activities.

The presence of nitrogenous waste in waterbodies is

associated with discharges from sewage treatment plants.

The presence of synthetic semi-volatile organic
compounds in waterbodies is associated with discharges

from industrial and commercial land uses.

The presence of synthetic semi-volatile organic
compounds in waterbodies is associated with runoff (non-

point source) from urban land use.

The presence of heavy metals in waterbodies is
associated with discharges from industrial and

commercial land uses.

The presence of heavy metals in waterbodies is
associated with runoff fi-om agricultural crop production

activities.

Q
(8) The presence of total and fecal coliforms in waterbodies
is associated with runoff from agricultural crop

production activities.

(9) The presence of total and fecal coliforms in waterbodies
is associated with discharges from sewage treatment

plants.

Description of Study Area
A . Selection of Sampling Sites

Land use maps were studied to obtain a general pattern of the
distribution and types of land use on the island. This was followed by the
examination of air photographs from 1985 at a scale of 1:20,000 in order to
update the data portrayed in the maps and to make a preliminary selection
of sampling sites. Field visits were necessary to corroborate the adequacy
of the sites in terms of their accesibility, and any changes in land use not
previously identified. Three watersheds were chosen (Fig.4 ) and among
these, 33 sampling sites were selected: 12 in the Cibuco River basin (Fig.5),
12 in the Guayanés River basin (Fig.6), and 9 in the Yagiiez River basin
(Fig.7). All samples were analyzed for a set of fifteen water quality
parameters. Laboratory analytical methods are described in Appendix A.

 

 

 

 

 

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D groundwater station

6|!“

 

 

 

 

 

 

Figure 6. Sampling Stations, Guayanes River Basin

 

 

 

Sampling Stations

Yaguez River Basin

0 sz River

3km

 

0 surface water station

E] groundwater station

 

L

 

 

 

 

 

Figure 7. Sampling Stations, Yaguez River Basin

47

Table 2. Sampling Stations and Surrounding Land Uses
Cibuco River Basin

 

 

 

 

 

 

 

 

 

 

Stations lWaterbody Landuse (1) Landuse (2) Landuse (3)
8 Pugnado well residential
9 Vega Baja well residential
10 Sabana Hoyos well residential sugarcane horticulture
11 Vega Alta well residential industrial
(electronic)
12 spring forest
5 Corozal River plantains
6 De Los Negros River residential textiles
7 Mavilla River livestock forest textiles
residential
3 Cienaga Prieta residential sugarcane industrial
channel (chemical)
4 Cibuco River sugarcane grassland
2 Hicatea creek forest livestock cattle

 

 

1 Morovis River f 0 re st sewage plant

 

 

Table 3. Sampling Stations and Surrounding Land Uses

Guayanes River Basin

 

Stations /Waterbody

Landuse (1)

Landuse (2) Landuse (3)

 

 

 

 

 

 

 

 

l Limones River livestock
2 Guayanes River sugarcane livestock residential
plantains
4 Guayanes River sugarcane commercial residential
11 La Grua well sugarcane industry
(sugar refining)
12 Roig well sugarcane industry
(sugar Ind.)
3 Aguas Largas creek residential forest
9 Santiago creek residential sugarcane
6 Santiago creek sewage plant sugarcane
5 Santiago creek Trib. textiles residential
7 Del Ingenio River industry sugarcane
(Union Carbide)
8 Aguacate creek industry livestock forest
(Reynold's
Tobacco)
10 Guayanes River sugarcane

 

 

49

Table 4. Sampling Stations and Surrounding Land Uses

Yaguez River Basin

 

Stations [Waterbody Landuse (1) Landuse (2) Landuse (3)

 

 

 

 

 

 

 

2 Boquilla creek sugarcane commercial

1 Marini well plantains forest

6 Yaguez River residential industry

3 Yaguez River commercial residential industrL
5 Grande creek residential forest

4 Sabalos creek industry residential forest

7 Majagual creek commercial textiles residential
9 Canas River coffee

8 Canas River coffee]

plantains

 

 

5O

Twenty-six of the sites are surface water bodies (streams, creeks),
and the remaining seven are wells used as potable water supply which
belong to the Puerto Rico Aqueduct and Sewage Authority. The spatial
design of the sampling sites is as specific as posible so as to differentiate

among suspected pollutant sources.

The sampling sites include water bodies associated with: point
sources of pollution in urban settings such as industrial plants and sewage
treatment plants effluents and in the rural areas, with livestock in
confinement. Non-point sources are represented by rural areas dedicated
to agriculture (sugarcane, coffee, pineapple, plantains), dispersed

livestock, and in the urban areas, by residential and commercial uses.

The name of each sampling site together with associated patterns of
land use (in diminishing order of predominance) is given in Tables 2, 3 and

4 respectively for the Cibuco, Guayanés and Yaguez basins.

Parameters Employed in the Study

The readings obtained for the water quality parameters considered
here indicate that the number of samples with detectable concentrations
exhibit variation among the parameters and among the three hydrological
basins. These concentrations were compared against the standards for
water quality in Puerto Rico (Table 5) which are prescribed by the Puerto
Rico Environmental Quality Board based on recommendation by the United
States Environmental Protection Agency (U.S.E.P.A.).

51

 

Table 5. Water Quality Standards
(All standard concentrations in parts per billion (PPB)

Parameters Surface Water Groundwam' Potable Water
Total Coliforms 10,000

colonies /100 ml 1-4

colonies /100 m1

Fecal Coliforms 2,000

colonies /100 ml
BOD-5 5,0000
Nitrate 10,000 10,000
Nitrite 1,000
Cyanide 20
Arsenic 50 0.022 50
Cadmium 0.68 (1) 10
(previous Std. 50.0) 1.22 (2)

1.48 - 1.72 (3)
Nickel 90.7 (1)

170.9 (2)

209.6 -246.9 (3)
Chromium 50 50
Lead 1.4 (1) 50 50
(previous Std.50.0) 3.6 (2)

4.9 - 6.3 (3)
Mercury 1.0 2.0

 

(1) Standard limits Guayanés River Basin
(2) Standard limits Yaguez River Basin
(3) Standard limits Cibuco River Basin

No published standards for ammonia and total Kjeldahl nitrogen

Sources:

Water Quality Standards Regulation, Ammended Version 1990, Environmental Quality Board,
Commonwealth of Puerto Rico.
Drinking Water Regulations, Regulation Number 50, Puerto Rico Department of Health.

52

The Water Quality Standards Regulation for Puerto Rico was
amended in 1990, during the period of this field study. In the amended
version standard limits have been set for the first time for concentrations of
cadmium, lead, arsenic and selected plaguicides in groundwater. The
numerical limit set for arsenic is of 0.022 ug/l. This number is based on
recommendations contained in the document Water Quality Criteria of 1986
by the U.S.E.P.A. (D. Laaves, Puerto Rico Environmental Quality Board,
oral communication, 1991). The new standard limit is a very low
concentration, particularly when compared against the standard of 50.0
ug/l for arsenic in surface waters and drinking water as well. The
discrepancy reflects the need for changing standards, and delays in the

process.

Groundwater samples in this study were withdrawn from wells
being used for potable supply by the Puerto Rico Aqueduct and Sewer
Authority (P.R.A.S.A). The samples were collected from pipe connections
prior to receiving the chlorination treatment provided by the authority
before its distribution for public consumption. However, chlorination by
itself does not eliminates substances such as heavy metals or chemical
forms of nitrogen if they are present in groundwater. Thus, with the
exception of the parameters for total and fecal coliform colony counts, the
concentration of substances from groudwater will be compared against the

regulated standards for drinking water.

The new regulation also sets a standard limit for nickel in surface
waters. The setting of this and other heavy metals standards now takes
into consideration water hardness since calcium carbonate is known to

influence the toxicity of metals. ’ Formulations have been developed that

53
estimate the decrease in toxicity of certain heavy metals with increasing
hardness. These formulations permit higher ambient levels of metals in
hard waters than they do in soft waters. Concentrations of calcium
carbonate were not obtained during sampling, since water hardness was
not a variable required in the setting of standard limits for heavy metals at
the time the samples were being collected. However, in order to have an
estimation of the quality of the waters sampled under the new amended
regulation for heavy metals, values for the concentration of calcium
carbonate were obtained from the United States Geological Survey in their
Water Resources Data, Water Year 1989. The concentration readings were
selected from streams, although not the same sampling stations, in the
three hydrological basins under study. Samples were collected by the
U.S.G.S. in August 1989, two months before the collection of the first

samples for this survey.

Regarding semi-volatile compounds, there are no specific water
quality standards, however the regulations state that the waters of Puerto
Rico shall not contain any substance in a concentration which is toxic or
which produces undesirable physiological responses in human, fish or
other animal life, or plants. Moreover, the waters of Puerto Rico shall not
contain two or more substances whose combination is toxic. However no
information is available as to assess the toxic concentration limit for the
semi-volatile compounds detected, either by themselves or in a combination
that may promote additive or synergistic effects. Although some potential
toxicants are mentioned specifically in stream or drinking water

standards, many others are not because they may have been developed only

54
recently or their potential for causing harmful effects is not yet fully

understood.

All samples were collected from untreated waterbodies. The
doubtful fecal origin and the inappropriate use of total coliforms as an
indicator of fecal water pollution is well documented. Growth of coliforms
can occur in tropical waters and they can survive several months in
natural tropical river water. Fecal coliform enumeration is less
ambiguous than total coliform enumeration, however, recent studies have
demonstrated that Escherichia coli, the target organism of the fecal
coliform group is capable of long term survival in tropical environmental
conditions (Hazen et al, 1985). Nevertheless, bacteriological water quality
standards in Puerto Rico are based on parameters of colony counts for the

coliform group. Hence, the inclusion of this parameter in the study.

CHAPTER 1v

ANALYSIS OF RESULTS BY HYDROLOGICAL BASIN

In this chapter a description of each hydrological basin and the
readings obtained for the set of parameters under study will be discussed.

A . Yaguez River Basin

The Yagiiez river has its origin in the municipio of Mayagiiez, into
which bay it discharges. The basin extends 8.2 miles east from the
Mayagiiez Bay and into the Cordillera Central mountain range. The 12.9
square mile drainage area includes the most densely populated portion of
the City of Mayagiiez. Two main tributaries, Caricosa and Gandel Creeks,
which flow roughly parallel to the Yagiiez river comprise the drainage

pattern of the basin.

The mountainous portion of the watershed is largely covered by trees
and brush with practically no grass. This, combined with the steep slopes
result in high rates of runoff and erosion. The City of Mayagiiez occupies
the northern portion of the coastal plain, and it extends into the
surrounding foothills. Since the terrain within the watershed is extremely
rugged with elevations as high as 1,575 feet, the most accessible land areas
have been substantially populated. To the south the cover consists of
pasture in the foothills, with sugar cane fields extending westward into the

coastal plain.

56

In the Yagiiez river valley, alluvium is the principal aquifer and has
a maximum known thickness of 200 feet. The alluvial deposits are
underlain by alternating layers of elastic sediments and limestone.
Goundwater recharge occurs principally from rainfall infiltration, and
discharge occurs mostly as seepage to the streambed (U.S.G.S., 1987).
Urbanization has approximately covered the entire valley area and the use

of the alluvial aquifer has been abandoned.

The temperatures are relatively moderate and uniform throughout
the year, following the general temperature pattern of all coastal areas of
Puerto Rico. The average annual temperature for the coastal plain is 77.5
Farenheit degrees, and for the highlands at the east limit of the watershed
is about 75 Farenheit degrees.

Average annual rainfall is about 76 inches in the coastal plain and
increases to approximately 100 inches in the eastern mountainous region.
The average monthly precipitation was as follows during the sampling
period: November 2.27 inches or 0.61 inches below normal; January 0.36
inches or 0.59 inches below normal; March 4.67 inches or 1.14 above normal
(National Oceanic and Atmospheric Administration, 1989 and 1990).

The municipio of Mayagiiez, which is the only one contained in this
small basin, is located in the central portion of the west coast. It covers 77
square miles (199 sq. kilometers) sub-divided in 21 barrios. The City of
Mayagiiez is the third largest Metropolitan Area and ranks third among
developed cities in Puerto Rico. Consequently, the Yagiiez River basin is
the most densely populated of the three watersheds under study. The
population of Mayagiiez was estimated at 109,213 inhabitants in 1990 or

57

1,418.4 persons per square mile. In 1930 the population figure was 58,270
inhabitants or 757 persons per square mile, and there was an increase in

1960 to 83,850 or 1,089 persons per square mile.

When the total 60 year period is considered, the population increase
has been 661 persons per square mile since 1930, with about half of this
increment occurring during the period between 1930 to 1960, and the other
half occurring during the last 30 years. Mayagiiez has 89.1 percent of its
inhabitants classified as urban dwellers, the highest percent of urban

population for the three basins.

The economy of Mayagiiez is based on manufacturing and
commerce. In 1985 it had about sixty industries, among them, tuna
canning, chemical and pharmaceutical products, electric and electronic
equipment, food and beverages, and rum distilling. Sugarcane and cattle
are the principal agricultural products of the region. Coffee cultivation also

remains important in this western part of the island.

In this basin the standards for total and fecal coliforms were
exceeded at all surface water stations during the third sampling (Table 6).
The readings reached 2,400,000 colony counts/ml. Since precipitation was
above average during this sampling activity, the high readings obtained for
all surface water stations can be attributed to runoff from urban and rural

areas as well.

Precipitation was below normal during the first two samplings,
under those circumstances the standards for total and fecal coliforms were

also violated in most of the stations, but the colony counts were not as

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Generalized Land Use, 1990

Yaguez River Basin

 

0 surface water station

[:1 groundwater station

industrial

“ commercial
residential

agriculture .9

 

3km

 

 

pasture

 

 

 

 

 

 

Figure 8. Generalized Land Use, 1990 - Yaguez River Basin

61

elevated. Overall, the Yaguez river basin was found to be the most

bacteriologically contaminated of the three basins under study.

However, the BOD-5 parameter, an indirect test to indicate the gross
amount of organic material in water, was above the standard limit in only
two of these stations. Nevertheless, the highest BOD-5 reading in this
basin (15.7 mg/l) was obtained from the same station, and sampling, at
which the highest concentration of semi-volatile organic compounds (39 8
ug/l) were detected This was also the highest concentration. of semi-volatile

organic compounds detected in the survey.

The station in question (Y agiiez basin #7) is surrounded by three
main urban activities: industrial (textiles), commercial (supermarket), and
residential. From the first sample taken at this station, nine semi-volatile
compounds were separated through the GC/MS method. Their
concentrations ranged from 0.1 ug/l to 9.1 ug/l (Appendix B).

Among the compounds detected diphenylhydrazine, a carcinogen,
was identified in a concentration of 9.1 ug/l. Although there is no water
quality standard for this compound, the quality criteria for water issued by
U.S.P.A. in 1986 (U.S.E.P.A., 1986) recommended that for the maximum
protection of human health from the potential carcinogenic effects of being
exposed to this compound through the ingestion of contaminated water and
contaminated organisms, the ambient water concentration should be zero
based on a non-threshold assumption for this chemical. Recognizing that
a zero level may not be attainable, concentrations which may result in
incremental increase of cancer risk over a lifetime are estimated. A

concentration of 4 nanograms per liter (0.004 ug/l) is recommended as a

62

minimum risk level in water that is going to be ingested. For consumption
of aquatic organisms only, excluding consumption of water, the level

recommended is 0.056 ug/l.

Detectable concentrations of other compounds were identified at the
same station, among them, 1-Aminonaphthalene, another carcinogen
regulated by OSHA, in a concentration of 6.3 ug/l. Also detected were 7.3
ug/l of dodecanamide, N-(2-hydroxyethyl) or decanamide,N-(Z-
hydroxyethyl), both of which have been used as pesticides. The two other
samples from this station did not contain detectable concentrations of semi-
volatile organic compounds, which may indicate that the sources from
which they were generated are intermittent, all of which have implications

for monitoring purposes.

The E.P.A. water quality criteria do not have regulatory impact.
They are criteria based on scientific data and guidance of the
environmental efi'ects of pollutants which can be useful to derive regulatory
requirements. Although some potential toxicants are mentioned
specifically in stream or drinking water standards because their effects are
known, or may be reasonably estimated, many others are not because they
may have been developed only recently or their potential for causing
harmful effects at the low concentrations commonly encountered in waters

are uncertain.

Although this is not the only station in the basin in spatial
association with urban land uses, and even though the concentration of
semi-volatile compounds in the other stations were all below the

concentration of one part per billion, the compounds detected and identified

63

can be constituents or by-products of the urban related activities
surrounding it. Phthalates, for example are known ubiquitous
plasticizers, although some of them have been used as pesticides.
Recommended concentration levels for phthalates vary according to the
particular phthalate, but they are in the order of a milligrams per liter, a

concentration level that was not found in any of the samples.

None of the parameters related to nitrogenous waste were detected at
above standard limits. The presence of nitrate or ammonium might be
indicative of pollution through disposal of sewage or organic waste. The
sources of organic nitrogen include not only natural materials, but also
numerous synthetic organic ones likely to be associated with industrial
processes. BOD-5 was exceeded three times at two sites in association with

industrial and commercial land.

Among the heavy metals, the standard for mercury in surface
waters was violated at five of the eight surface stations. Inorganic mercury
is relatively insoluble and is not usually a threat to the human food chain,
but organic complexes of mercury such as methyl mercury can be produced
by methane-generating bacteria in contact with metallic mercury in lake or
stream sediment. The surface water quality standard (1.0 ug/l) was issued
to protect waterbodies or the aquatic life from the potential for
bioaccumulation through the food chain. The highest measurement
readings (2.5 and 2.3 ug/l) were detected at sites surrounded by urban land
uses (residential, industrial, commercial). These are also the highest
readings obtained for mercury, all samples considered. Various cultural
uses of mercury, such as battery cells, paints, agricultural uses and

pharmaceuticals, and its release to the atmosphere in smelting and fossil-

64

fuel combustion have probably raised the general background level of this
element in the environment. However, the amount of mercury that would
be present in water open to the atmosphere is low owing to its tendency to

escape 38 a vapor.

The surface water parameter for chromium (50.0 ug/l) was not
violated at any of the stations in this or the other two basins. The standards
limits for lead, nickel and cadmium were not violated either according to
the previous regulation. However, if the concentration of these three
metals were to be evaluated against the concentration of calcium carbonate
in the station selected for the Yaguez River basin (110 mg/l), their respective

standard limits would have been lowered.

In the case of lead it would have dropped from 50.0 ug/l to 3.59 ug/l.
This numerical limit was exceeded at all surface water stations during the
second sampling. The highest lead concentration was 22.6 ug/l detected at
the same site, although not the same sampling time, at which the highest
concentration of semi-volatile organic compounds was detected. The first
sample collected at each of these stations did not give lead readings above
standard limits, in fact, all except the sample from groundwater, were
reported as being below the detectable concentration of 0.05 ug/l. The
concentration of lead at the well was 1.1 and 8.1 ug/l during the first and
second samplings respectively, which are not above the limits for this metal

in either drinking water or groundwater regulations (50.0 ug/l).

The standard limit for cadmium would have also been lowered from
5.0 ug/l to 1.22 ug/l if the concentration of calcium carbonate were to be

considered. A limit that was surpassed at five surface water stations with

65

a highest reading of 2.6 ug/l from a stream surrounded by a coffee
cultivation area. The other stations exceeding the numerical limit included
almost all the other land uses in the basin. Cadmium is known to be
present in fertilizers. However the amount of this metal added to soil in
this way is very low. More important sources of cadmium are the
industrial uses for electroplating, pigments and plastics. The
concentrations of cadmium detected at the groundwater station were below
the standard limits for drinking water (10.0 ug/l) and groundwater (5.0
ug/l) as well.

Nickel did not have a standard limit in surface water in the previous
regulation. The new standard limit, based on the concentration of calcium
carbonate, is of 170.91 ug/l in surface waters. This limit was not violated at
any of the stations. However E.P.A. quality criteria for water in 1986
recommends a concentration of 13.4 ug/l for the protection of human health
from the toxic properties of nickel ingested through water and
contaminated aquatic organisms. The highest nickel concentration
detected in this basin and in the whole study area was 44.6 ug/l. The nickel
concentration at the groundwater sample was below the detectable

concentration (0.1 ug/l).

The only parameter violated in the sample from groundwater was
arsenic. This metalloid was detected at a concentration of 4.2 ug/l at one of
the sampling activities. A concentration that is below the standard limit
for potable water (50.0 ug/l), but above the numerical limit set as the
standard for groundwater (0.022 ug/l) in the amended regulation. Small
amounts of arsenic, a suspected carcinogen, occur in many natural

materials, with trace amounts occurring in soil and water. Arsenic has

66

been used as a component of pesticides, especially before 1960, and thus
may enter streams or groundwater through waste disposal or agricultural
drainage. Arsenic may be present as organic compounds or in inorganic
complexes. Its toxicity is therefore a variable that can be determined only

for defined forms of arsenic and biological targets (Landner, 1989).
B. CibucoRiverBasin

The Cibuco river basin is located in the municipios of Vega Baja,
Vega Alta, Dorado, Morovis and Corozal. The Cibuco River has an
estimated length of 22 miles (35 Kms.). It rises in the northern foothills of
Puerto Rico at an elevation of approximately 600 meters, flows northward
and enters the Atlantic Ocean approximately 30 kilometers west of the

capital city, San Juan.

The tributaries of the Cibuco river are: Corozal River, Dos Bocas
River, De los Negros River, Mavilla River, Indio River, Morovis River,
Unibén River, Las Carreras River, El Toro Creek, Grande de Morovis
Creek, Honda Creek and Cabo Caribe Creek. The total drainage area is
approximately 131.7 Sq. miles (341.1 Sq. Km), although the exact drainage
area is indeterminate due to the karst topography.

The lower part of the Cibuco basin is contained in the North Coast
Province, one of the six main aquifer areas into which the United States
Geological Survey has divided the island. The North Coast Province is
composed primarily of Tertiary limestone and elastic beds. Groundwater
in the area of the Cibuco basin exists under water-table conditions in the

limestone rocks, alluvial valleys, and coastal plain deposits.

67

The North Coast Province is the principal aquifer system on the
island and is also the one under greatest pumping stress. Since 1968,
numerous wells have been drilled for industrial water supply near the
coast and for public water supply further inland. In addition,
groundwater flow in this area has been significantly changed from its pre-
development conditions. [The most significant change to the hydrology has
been the dewatering of coastal wetlands and the construction of a drainage
channel connecting Laguna Tortuguero with the Atlantic Ocean. The
large scale effects of these changes have not been assessed. In addition,
groundwater withdrawals have increased from 10 million gallons per day
in the early 1940's to an estimated 60 in 1985 (U.S.G.S.,1987). Withdrawals
by wells situated within the alluvial valleys are estimated at 8 million

gallons per day.

The large scale modifications of groundwater flow within this area
make it difficult to establish the regional flow regime. In general it is
known that recharge occurs throughout the entire outcrop areas of the
limestones and at topographic depressions throughout the blanket deposits.
Also, the effects of streams and thick alluvial deposits on the flow system
have not been adequately defined.

The climate of the Cibuco basin is characterized by a small range in
temperature between the warmest and coldest months, with a mean
annual temperature of 80 degrees F (27 C). Average annual rainfall over
the Cibuco basin is between 1.5 meters and 1.8 meters (59-71 inches). The
precipitation during the sampling period was below normal as the
following average monthly rainfall figures indicate: November, 3.46 inches

or 0.94 inches below normal; January, 4.38 inches or 0.39 inches above

68

normal; March-April, 3.10 or 1.68 inches below normal (National Oceanic
and Atmospheric Administration, 1989 and 1990).

The total population in 1930 for the municipios in this basin was of
66,525 inhabitants or 505 persons per square mile, it increased to 102,916 in
1960 or 781 persons per square mile, and in 1990 it was reported as being of
170,298 or 1293 persons per square mile. The total population increase over
the last 60 year period has been of 788 persons per square mile, but out of
this figure 65 percent or 511 persons per square mile increase has occurred
over the last 30 years alone, when the industrialization and urbanization

processes were taking place.

Of the total population in these municipios 50 per cent is classified as
urban. The population of Vega Alta is 71.5 percent urban, which is the
highest percent among all the municipios in the basin. In contrast, the

urban population of Morovis,in the mountain area, is only 12 percent.

These two municipios are an example of the general social and
economic pattern that has taken place in Puerto Rico as a whole in the last
40 years. Urban and industrial activities predominate in coastal plains but
diminish toward the mountain areas Vega Alta is located on the northern
coast, one of the most industrialized regions on the island. This municipio
itself has several industries, including: paper, glass and ceramic, electric
and electronic equipment, metal tubes and machinery. There is also
floriculture and minor fruits cultivation, as well as poultry and livestock
activities. While Morovis, located in the central mountain region of the
island, has some small manufacturing industries, cattle, coffee and fruits

are the main economic activities. Typically, population concentrations

69

occur where the demand for jobs can be supplied not only by the industries
located there, but also by a whole range of services offered at the urban

centers.

The basin as a whole contains several land uses: industrial,
particularly textile products, and electric and electronic equipment;
agriculture, with the predominance of sugarcane, plantains, pineapple
and minor fruit cultivation, as well as as some livestock and poultry
activity. Although all municipios have urban and rural sectors, and thus,
commercial and residential land uses are present throughout the basin,
the concentration of these uses is particularly important toward the coastal

low lands.

Of the twelve stations sampled in this basin, six violated the standard
for total and fecal coliforms, particularly during the second sampling,
when precipitation was greater (Table 7). The highest reading for total
coliforms was of 160,000 colonies/ml at two stations in spatial association
with residential and livestock activities. For fecal coliforms the highest
reading was 92,000 colonies/m1 at a site surrounded by residential land use.
However, the BOD-5 parameter was not violated at any of the stations or

sampling times.

In this basin the highest reading for semi-volatile organic
compounds was obtained from a groundwater sample (4.4 ug/l). One ug/l of
mercaptobenzothiazole and 3.4 ug/l of petroleum hydrocarbons were
detected during the third sampling. Mercaptobenzothiazole is a toxic

substance used as a vulcanization accelerator for rubber and is also a

70

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Generalized Land Use, 1990

Cibuco River Basin

      

g industrial

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Figure 9. Generalized Land Use, 1990 - Cibuco River Basin

73

fungicide. Traces of phthalates were detected at the other three wells

sampled in this basin.

All groundwater samples gave measurement readings of arsenic
above 0.022 ug/l. The highest concentration was 4.9 ug/l obtained at two of
the sites surrounded by residential, sugarcane cultivation and industrial
land uses. Regarding heavy metals, mercury standard limit was violated
at two of the stations with residential and industrial uses surrounding
them. The highest reading was of 1.3 ug/l. The other heavy metals under
study did not exceed their limits according to the previous regulation. But
as indicated above the concentration of calcium carbonate as reported by the
U.S.G.S was taken to roughly estimate what would have been the new
standard limits for lead, cadmium and nickel.

In this basin two measured concentrations of calcium carbonate are
used, each belongs to two difl‘erent sampling sites in the Cibuco basin, one
in the mountain area close to Corozal Pueblo, and the other in the coastal
plain , close to to the river mouth. The concentration reported at the station
in the mountain area was of 140 mg/l of calcium carbonate. At the other
station it was of 170 mg/l, the highest for the entire sampling area. The
standard limits for the metals vary according to these concentrations.

The standards obtained for cadmium were of 1.48 and 1.72 ug/l for
the mountain and coastal stations respectively. Only one surface station
exceeded the limit (1.6 ug/l). This is a station that receives the effluents
from a sewage treatment plant. None of the groundwater samples
exceeded the limit for cadmium in the groundwater or potable water

regulations.

74

Limits for lead, as obtained by the concentration for calcium
carbonate, are 4.88 and 6.25 ug/l for the mountain and coastal stations. All
surface water stations violated the standard for lead during the second
sampling. The highest concentration detected was 20.7 ug/l at a site
surrounded by residential and industrial land uses. None of the
groundwater samples violated the lead standard for groudwater or potable

supplies.

The standard for nickel at the two stations would have been set at
209.59 and 246.99 ug/l at the mountain and coastal stations, but none of the
samples were above these numerical limits. Nevertheless, the highest
level detected in this basin was of 17.8, which is above the level

concentration of 13.4 reccomended by E.P.A.
C. Guayanés River Basin

The Guayanés River is approximately 11.5 miles (28 kilometers) long
with a total basin area of 53 square miles (136.19 kilometers). The
Guayanés River originates in the municipio of Yabucoa, located in the
southeast coast of Puerto Rico, and discharges in the Caribbean Sea. Its
tributaries are Prieto River, Limones River, Ingenio River, Alejandro

Creek and Guayabo Creek.

The municipio of Yabucoa has minor elevations to the north. In the
south it has the Santa Elena peak at 1870 feet (570 meters) above sea level.
The area comprising the municipio of Yabucoa is part of the San Lorenzo
batholith, a granodiorite intrusive. Alluvium consists largely of clay, but
has appreciable amounts of sand. Thickness of these deposits are as much

as 300 feet in the center of the valley and average 100 feet in most areas.

75

Groundwater in this stream valley aquifer is under unconfined conditions
within the unconsolidated deposits. In general, groundwater flows toward
the coast. Recharge occurs along the alluvium-bedrock contact from
numerous streams and from areal rainfall infiltration throughout the
alluvium. Discharge has been significantly modified by groundwater
withdrawals, which have been estimated at less than 5 million gallons per

day.

The average temperature in the coastal area is around 77 degrees
Farenheit and diminishes toward the interior mountain area to an average
of 72 degrees. The average annual precipitation ranges from 72.2 inches at
the coast to 110 inches in the mountain area. During the collection of
samples the average monthly precipitation was as follows: November, 3.45
inches, no departure from normal; January 6.05 inches,no departure from
normal; March 4.16 inches, no departure from normal (National Oceanic

and Atmospheric Administration, 1989 and 1990).

The municipio of Yabucoa covers 55 square miles (142 sq. kilometers)
sub-divided in 10 barrios. The population in 1930 was of 21,914 inhabitants
or 398 persons per square mile, in 1960 it increased to 29,782 or 542 persons
per square mile, and in 1990 it is reported to be of 31,898 inhabitants or 579.9
persons per square mile. This represents an increase of 182 persons per
square mile for the entire 60 year period. In the last 30 years alone the
population increase has only been of 38 persons per square mile, or 2,116
more inhabitants. Also, Yabucoa has 29.8 percent of its population
classified as urban, all of which makes the Guayanés River basin the one,

among the three under study, with the lowest population density, as well as

76

the one with the lowest percent of urban population, this regardless of the

industrial development in the Yabucoa municipio.

The economy is based on sugarcane cultivation and industrial
activity. The Roig sugarmill, located there is one of the four mills that has
continued working in Puerto Rico. Other industries established in
Yabucoa are as diverse as a petroleum refinery, clothes manufacture,
cigarettes manufacture, graphite electrodes and electric equipment

industries.

Eight of the twelve sampling stations violated the standards for total
and fecal coliforms (Table 8). These violations occurred mostly during the
second and third sampling activities. These were the months during
which precipitation was higher in the southeastern part of the island,
although not above average. Runoff from areal sources of this type of
bacteriological pollution could have been increased during that period. The
stations at which the standards for these parameters were violated were
typically associated with livestock activity and residential land use. The
highest total coliform colony count was of 240,000/ml at one of the stations
surrounding the town of Yabucoa, which is an extensive area of impervious
surface. However, the highest fecal coliform colony count was of
160,000/ml at a station associated with the outfall of a sewage treatment

plant.

The standard for biochemical oxygen demand was violated during at
least, one of the of the sampling activities at all stations, including those
from groundwater samples. BOD-5 is not a standardconsidered in the

77

 

 

  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Generalized Land Use, 1990

Guayane’s River Basin

.—

 

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Figure 10. Generalized Land Use, 1990 - .Guayanes River Basin

80

drinking water or groundwater regulations, but the two wells sampled in
this basin gave readings above 5,000 ug/l, the standard in surface waters.

The two wells are surrounded mainly by sugarcane fields and the
sugarmill industry. It is possible for fertilizers and pesticides from
cultivated fields to percolate and reach the aquifer. In surface waterbodies,
herbicides and insecticides in addition to being a source of toxic
compounds, can also contribute to the BOD of the receiving waters. In fact,
it was at one of this wells that the highest concentration of semi-volatile
organic compounds (4.6 ug/l) for all groundwater sampled in the survey
was detected. Through the GC/MS method a separation and identification
of a concentration of 4.4 ug/l of Di-n-butyl-phthalate was obtained from this
sample. This is a compound classified as a priority pollutant, which has
been used as an insect repellant. At the other well trace levels of other
phthalates were also detected. Although these are relatively small
concentrations, their presence in groundwater indicates that

contamination of the aquifer from human activities is taking place.

Detectable concentrations of semi-volatile organic compounds, above
1.0 ug/l were found at six of the twelve stations sampled in the Guayanés
basin. The highest concentration was 8.0 ug/l at a station in spatial
association with industrial (textile manufacture) and residential land uses.
Not all of the compounds detected at this site could be identified but they
included petroleum derived hydrocarbons, sulfur, and diethyl phthalate.

Diethyl phthalate is a priority pollutant that has been used in the
manufacture of celluloid, varnishes and dopes. The presence of sulfur in

elemental form may be as a result of the separation of compounds in the

81

analytical column of the GC/MS. However, many products or by-products
of industrial processes contain sulfur. Traces of anthracene and
fluoranthene were also detected at this station. Both compounds are
priority pollutants described as policyclic aromatic hydrocarbons. They are
formed during the combustion of many materials. Anthracene is used in
dyestufl‘ manufacture and is also a major constituent of coal tar neutral
oils. Water quality criterium for fluoranthene suggests a concentration

level of 42.0 ug/l in ambient water.

Compounds such as caprolactam and adipic acid, used in the
manufacture of synthetic fibers, were detected in waterbodies in spatial
association with commercial and residential land uses in this basin. This
is an indication that industrial activities are not to be identified as the only

sources of synthetic organic compounds.

Regarding concentrations of heavy metals, the standard for mercury
in surface waters (1.0 ug/l) was violated at two stations during the second
sampling. The highest reading in this basin was 10.7 ug/l at a station
surrounded by sugarcane cultivation and a graphite electrode industry.
The second highest reading was detected also at a site in association with a

sugarcane field.

While there is no standard limit for mercury in untreated
groundwater, the drinking water standard for this metal is 2.0 ug/l, which
doubles the numerical limit standard for mercury in untreated surface
waters (1.0 ug/l). A concentration of mercury of 2.7 ug/l was detected in
one of the wells during the first sampling. The second sample provided a

concentration of 1.5 ug/l. It was at this well that the highest concentration

82

of semi-volatile organic compounds was detected in this basin. The
detection of a pesticide and mercury in this well may be indicative of
contamination of the aquifer with substances used in the agricultural and

commercial land uses surrounding it.

Lead, cadmium or nickel were not detected at above the standard
levels establised in the previous regulation. However, when the
concentration of calcium carbonate is considered (52.0 mg/l) violations for

lead and cadmium standard limits occur.

A numerical limit for cadmium of 0.68 ug/l was violated at all
surface water stations during the second sampling. The highest
concentration was 2.0 ug/l at a site in association with a sugarcane
cultivation area. None of the groundwater samples had readings above the
standard for cadmium in groundwater or drinking water.

The lead standard limit of 1.38 was violated at nine of the stations.
The highest reading was 41.6 ug/l and it was obtained at a site receiving the
effluents from a sewage treatment plant. This was the highest reading for
lead for the whole study area. Lead concentration were not in violation at

any of the wells in the basin.

A nickel concentration of 14.3 was the highest detected in this basin.
As mentioned before E.P.A. suggests a concentration limit of 13.4 ug/l.
However, the standard limit of 90.7 ug/l for nickel in surface waters was
above any of the measurements obtained in this basin in surface or

groundwater samples.

83

As in the other two basins, the detection of arsenic was above the
standard for groundwater in the two samples obtained from that source in
this basin. Violations occurred during the second sampling and the

concentration at both station was of 4.3 ug/l.

In summary, each of the three basins reveals frequent violations of
water standards and also numerous near-violations. These include fecal
coliforms, oxygen demand, nitrogen, heavy metals and semi-volatile
organic compounds. Particularly regarding surface water, the main
feature that the three basins have in common is widespread contamination.
Possible threats to human health must be considered in both the short and

long run, but cannot be evaluated here.

CHAPTER V

ANALYSIS OF RESULTS BY LAND USE

The number of samples with detectable concentrations of pollutants
exhibit considerable variation among the parameters and among the land
uses in the data set. With the exception of the parameters for total and
fecal coliforms, the maximum concentrations also show considerable

variation between land uses.

The distribution of highest concentrations detected by land use
indicates that water samples taken from sites in spatial association with
land uses that were predominantly urban (industrial, residential) have a
larger number of parameters with maximum concentrations when
compared with the other land uses included in this study (Table 9). This

pattern was consistent throughout the three basins.

Municipal and industrial uses of water are directly related to, and
largely based on, water carriage of wastes. For example, most industrial
uses of water are for the removal of heat, impurities, or by—products from
various types of processes. Also the discharge of wastes into other
locations such as into air or land does not prevent wastes from ultimately
reaching water bodies. Examples are the many instances of serious
groundwater and surface water pollution by leachates of materials buried
in landfills that enter the aquatic environment by leaching into water

passing through the deposit.

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86

I . Maximum Concentrations per Land Uses
1 . Agriculture (crops)

Water samples in spatial association with this type of land use (Table
10) exhibited highest concentrations for the heavy metals lead (41.6 ug/l)
mercury (2.7 ug/l), and cadmium (2.6 ug/l), the nonmetallic element

arsenic (23.0 ug/l), and the highest biochemical oxygen demand (45.0 mg/l).

Among these highest concentrations, lead, cadmium and mercury
violated the standards for surface waters. The surface water quality
standard for mercury has been set to 1.0 ug/l to protect waterbodies or the
aquatic life from the potential for bioaccumulation through the food chain.
Inorganic mercury is relatively insoluble and is not a threat to the human
food chain, but organic complexes of mercury such as methyl mercury can
be produced by methane-generating bacteria in contact with metallic
mercury in lake or stream sediment. Consumption of aquatic organisms
with excessive concentrations of methyl mercury can have severe effects on
the central nervous system. Chemicals that bioaccumulate in food chains
may create problems even though their concentrations in the water are well
below objectionable levels. The standard for mercury was violated at a
groundwater site, associated with crop cultivation activities; 2.7 ug/l at the
Guayanés station #12 was the highest mercury reading from groundwater
samples. The current drinking water standard for mercury is 2.0 ug/l.

While the highest concentration of arsenic was of 23.0 ug/l in a
surface waterbody and thus, does not violate the standard numerical limit
0f 50.0 ug/l, the highest concentration of arsenic from a groundwater

87

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sample was 4.9 ug/l, a number that violates the standard for groundwater.
One of the readings belongs to a well in close proximity to the surface
waterbody with highest level of arsenic (Cibuco River Basin, stations #3 and
#10). The relationships among groundwaters and surface waters are
vitally important. Flows into and out of porous soils exchange water
storage between a surface reservoir and an adjoining aquifer. Studies
with arsenic indicate that this metal is not bioconcentrated to a high degree
in fish, and thus do not represent a threat to fish predators, but that lower

forms of aquatic life may accumulate higher arsenic residues than fish

(E.P.A., 1986).

The highest BOD-5 and lead readings occurred at a sampling site
that was also in association with a water sewage treatment plant, hence

these will be discussed under that section.
2. livestock

The only maximum concentration above those detected in association
with other land uses was the concentration for nitrite (Table 11). Nitrites
are generally considered to be indicators of pollution through disposal of
sewage or organic waste. There are no quality standards for the

concentration of nitrites in untreated surface waters.

The standard for lead was violated at all stations during the second
sampling activity. The standard for the metals cadmium and mercury

were also violated at two of the stations associated with livestock activities.

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91

3. Industry

The highest concentrations in water samples collected from sites
surrounded by industrial land use (Table 12) were those for semivolatile
organic compounds (39.8 ug/l), ammonia (10327.0 ug/l), nickel (44.6 ug/l),
total kjeldahl nitrogen (39310 ug/l), chromium (32.0 ug/l), mercury (2.7
ug/l), and arsenic (23.0 ug/l).

Many of the organic compounds that have caused concern enter
watercourses in discharges from chemical manufacturing plants. On the
other hand, many others are released by operations that use them for
various purposes, and their concentration in water might be related to their
selection, handling and application, not necessarily the industrial
wastewater treatment. End uses of many of these componds tend to
disperse them in the environment. Daily activities of typical dense
population of urban areas produce wastes (personal, commercial, or
industrial) that eventually are discharged into the atmosphere, land or

natural waters.

Moreover, runofi’ water from impervious surfaces (e.g. parking lots,
buildings) becomes a vector for any component caught in its flow. It is
then, not surprising that urban related land uses present the highest
concentrations of these contaminants. Some organic chemicals are of
concern in stream pollution control programs because they biodegrade and
impose oxygen demand on watercourses. In contrast, other types of
organic chemicals cause concern for the opposite reason; they are not
decomposed through biological action and may persist for long periods of

time, or indefinitely.

92

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94

As mentioned above, the single highest concentration for semi-volatile
organic compounds was detected in the Yaguez River basin at a site
surrounded by industrial (textile), commercial (grocery store) and
residential land uses. In a study conducted by U.S.E.P.A. in the 1970's
(Comaby, 1981) to evaluate the technology available for the reduction of
pollutants from textile wastewaters selected pollutants and associated
measurements for the textile industry were examined. In analyses
performed on effluents from textile plants, observed concentrations of
priority organic pollutants ranged from 0.1 ug/l to 3000.0 ug/l. Among
these compounds were benzyl butyl phthalates, nitrophenols, anthracene,
diethyl phthalate, bis(2-Ethylhexyl) phthalate, di-n-butyl phthalate,
naphthalene as well as detectable concentrations of the heavy metals
cadmium, chromium, lead , nickel, mercury, arsenic and the compound
cyanide. All of these compounds were also detected in some of the samples

from industrial land uses in this study.

One of the most common types of industry in the study area was that
of textile products. In the Yagiiez basin, the station at which the highest
concentration of semi-volatile organic compounds were detected was one
associated with a garment industry for the manufacture of men's work
pants. In the Cibuco basin a compound that could not be identified was
detected in association with an industry fo the manufacture of mop linen,
and trace levels of another of these compound at a men's knitted shirt
industry. In the Guayanés basin, the highest concentrations of organic
compounds were detected at a surface water station in association with
industries for the manufacture of men's jackets, fabric stamping, and

leather products Although there were other types of industries at the other

95

sampling sites, the detection of semivolatile organic compounds was not as

high.

Concentrations of lead, mercury and cadmium violated the standard
limits in at least one of the samples at almost all the stations in industrial
land uses. However, the highest concentrations of lead and cadmium were
not detected at sampling sites from industrial land uses. The reading for
mercury was detected at the well sampling site discussed above.

Nickel, another heavy metal, is an important industrial metal that is
used extensively in stainless steel and other corrosion resistant alloys, and
to a lesser extent for other purposes. Because of its extensive use, nickel
can be added to the environment in significant amounts by waste disposal.
Some nickel compounds may be carcinogenic. The highest concentration
of nickel was detected at a sampling station in association with industrial
(textile) land use, but the standard limit was not exceeded. However, the
detected concentration of 44.6 ug/l more than triples the limit suggested by
the U.S.E.P.A. for the protection of human health from the toxic properties
of nickel. The examination of the concentrations of nickel in all samples
indicate that these are higher in samples from industrial land uses,
although there are no violations to the current water quality standards. In
some instances chemicals discharged into the environment may undergo
reactions that transform them into substances with different toxicological
characteristics, as in the case of mercury. These possibilities may have
great significance in setting standards for allowable discharges of some
types of materials. The heavy metal chromium is known to be added to
fertilizers and industrial applications of chromium may produce waste

solutions containing chromate anions. The maximum concentration of

96

chromium of 32.0 ug/l was also detected at the sampling site in the Yaguez
river basin with highest concentrations for semi-volatile organics and
nickel. Although 32.0 ug/l is not above the current standard of 50.0 ug/l in
surface waters, concentrations of chromium in natural waters that have
not been affected by waste disposal are commonly less than 10 ug/l (Hem,
1985).

Ammonia can form soluble complexes with some metal ions, and
certain types of industrial waste effluents may contain such .species. There
is no water quality standard for ammonia in surface waters. The highest
detected level was 10,327 ppb at Guayanés station #5. The term total
kjeldahl nitrogen (TKN) reflects the technique used in the determination of
organic nitrogen and ammonia. The difference between TKN and
ammonia has been determined as organic nitrogen. Nitrogenous
compounds released in discharges may include nitrogen in organic
chemicals (organic nitrogen) and nitrogen present as ammonia, nitrites
and nitrates. Under appropriate environmental conditions, many
nitrogenous compounds undergo a series of biochemical reactions that
convert organic nitrogen to ammonia and oxidize ammonia to nitrites and
nitrates, a process called nitrification. The oxygen required in nitrification
can be a very substantial portion of the total oxygen demand in a waterbody.
At the industrial site where ammonia and TKN readings where the
highest, the BOD-5 was also the most elevated. The sources of organic
nitrogen include not only natural materials, but also numerous synthetic

organic ones likely to be associated with industrial processes.

Arsenic, as discussed above, occurs in many natural materials.

Apart fi-om its use as a component of pesticides the volatility of the element

97

contributes to the natural circulation of arsenic and some of its compounds.
Arsenic also may be released in the burning of coal and the smelting of
ores. The maximum concentrations of arsenic from industrial sites did
not exceeded the standard limit for surface waters. Nevertheless the
surface water station at which the highest concentration for arsenic was
detected has a chemical industry, residential and sugarcane cultivation as
associated land uses. Since the sources of arsenic are more related to
agricultural activities this can be expected to be the most likely source and
not the other two land uses mentioned. The highest concentration of
arsenic from a well sample within this type of land use was the same as the
highest concentration detected at a well surrounded by a sugarcane
cultivation (4.9 ug/l). Without knowledge of the groundwater flow system
and boundary conditions in this aquifer it is not possible to identify pollutant
sources other than those in close proximity to a well. But an
interconnection of the aquifer system could be expected and revealed by the

presence of pollutants in common.
4. Commerce

Maximum concentrations for nickel (44.6 ug/l), semivolatile organic
compounds (39.8 ug/l), and chromium (32.0 ug/l) were detected in

waterbodies surrounded by commercial land use (Table 13).

The detected nickel concentration of 44.6 ug/l was the only one with
such a high nickel concentration when compared with the other samples
from commercial land uses. Since it is also surrounded by industrial
activity (textiles), it is feasible that this and not the commercial activity

could be the main source of the metal. The examination of nickel

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99

concentrations in all samples indicates that it is higher in areas of
industrial land uses. The concentration of chromium was also detected at
sampling sites in association with industrial activity. The chromium

concentrations at other commercial land use sites were not as high.

It was also in the Yaguez basin, station #7 that the highest
concentration for semi-volatile organic compounds was detected. But
runoff from commercial areas can transport different types of organic and

inorganic chemicals to receiving waterbodies.

Lead, mercury or cadmium concentration levels were above
standards in all stations during at least one of the sampling activities,
although their highest concentrations were not detected in association with
this type of land use. Washing of these metals into streams during runoff

events is a potential source of river water contamination.
5. Residential

Highest concentrations of ammonia (10327.0 ug/l), nitrate (6200 ug/l),
TKN (39310 ug/l), and nickel (44.6 ug/l) occurred in water samples taken
from sites surrounded by residential land uses (Table 14).

The presence of nitrate or ammonium might be indicative of
pollution through disposal of sewage or organic waste, but generally the
pollution would have occurred at a site or time substantially removed from
the sampling point (Hem, 1985). Nutrients in sewage arise from human
wastes, detergents, street runofl‘, and industrial wastes. The detection of
nitrate and nitrite in surface waters should not be above 10,000 ug/l, in
order to protect a waterbody that may be use as a raw water source for

100

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103

public water supply. This standard was not violated at any of the sites

sampled.

The relationship between the parameters for ammonia, TKN and

organic nitrogen have been discussed above.

Regarding nickel, an adjacent industry (textile) is the most likely
source at the station in which this concentration was detected and not the

residential land use.
6. Sewage Treatment Plants

Sewage treatment plants are major sources of pollution and for that
reason are treated here as a separate type of land use. The parameters
with the maximum concentrations in spatial association ssociation with
this type of land use (Table 15) were biochemical oxygen demand (45000.0
ug/l or 45.0 mlll), cyanide (20.0 ug/l), and lead (41.6 ug/l).

Regarding lead, certain uses of this metal by humans have tended to
disperse the element widely through the environment. Lead is a soft, blue-
gray metal that serves no purpose in the human body, and, in fact, is toxic
in high enough doses. It is found in microscopic particles in the air, in
paint, food, household dust and outside dirt. It has been used for products
that range from car batteries to radioactive shields. Dry fallout and
rainout of particulate lead is probably a factor of major importance in the
circulation of the element. Water service lines may be major sources
of lead in water supplies. Lead rarely originates at a water treatment
plant. Instead lead from lead pipes or lead in solder and flux in copper

plumbing can dissolve in water. It is then possible for domestic waste

104

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105

water to contain appreciable concentrations of the metal. This domestic
waste is collected by sewage treatment plants, which are not efficient in the
removal of metals during the treatment process (Guthrie and Perry, 1980).
Nickel, another metal, was detected at a concentration of 14.3, above the

level recommended by U.S.E.P.A. as adequate.

Approximately 152 million gallons per day of sewage treatment water
are released to surface waters on the island. According to the U.S.E.P.A.
47.4 percent of the population in Puerto Rico is served by municipal sewer
systems designed to provide less than secondary treatment and only 2
percent is served by secondary treatment facilities. Primary treatment
removes about 30-40% of the pollutants in the influent wastewater.
Secondary treatment removes about 90%. Federal law mandates secondary
treatment as the minimum treatment which must be given to all municipal

sewage (Van der Leeden et al., 1990).

Cyanide, a chemical form of nitrogen, may occur in water affected by
waste disposal. The maximum concentration detected of cyanide was of
20.0 ug/l. This concentration corresponds with the numerical limit set in

the new regulation.

The biochemical oxygen demand, as mentioned above, is an indirect
test to indicate the gross amount of organic material in water. Pollutants,
primarily organic compounds, cause a reduction in dissolved oxygen.
These pollutants come primarily from untreated sewage, industrial
wastes, food processing plants, and feed lots. As more organic material
becomes available for bacterial utilization their population increases, the

demand for oxygen to break down the organic material increases, and a

106

depletion of oxygen results. Other oxidations (e.g., of nitrogenous or
sulphur-containing compounds) from chemical and or biological reactions
further reduce the water's oxygen content. Inmediately downriver from a
sewage treatment plant the biochemical oxygen demand is high, but as the
bacteria consume the oxygen, the BOD drops.

The water quality standard states that the BOD will depend on the
assimilative capacity of the particular waterbody which should comply with
the standard for dissolved oxygen. The standard for dissolved oxygen, set
to sustain most forms of aquatic life, is 5000 ug/l or 5.0 ml/l.

II. Groundwater Samples

In general, substances detected in samples from groundwater were
in less concentration than those detected in surface waters . The exceptions
occurred for the parameters nitrate and mercury. The maximum
concentration of nitrate detected from all samples, surface or underground,
was 6,200.0 ug/l and was detected at the well Pugnado #2 in the Cibuco
River basin. However, the current drinking water standard for nitrate is
10,000 ug/l.

The most common semi-volatile organic compounds detected in wells
were phthalates in concentrations of less than 1 ppb. However, Di-n-butyl
phthalate, used as an insect repellant. was detected at a concentration of 4.4
ug/l in well Roig within the Guayanés River basin. This well is
surrounded by three land uses: sugarcane cultivation, a sugarcane mill

and commercial uses.

107

Well Roig also violated the drinking water standard for mercury.
While there is no standard limit for mercury in untreated groundwater, the
drinking water standard for this metal is 2.0 ug/l, which doubles the
numerical limit set for mercury in untreated surface waters (1.0 ug/l). A
concentration of mercury of 2.7 ug/l was detected in well Roig during the
first sampling. The second sample provide a concentration of 1.5 ug/l. The
detection of a pesticide and mercury in this well may be indicative of
contamination of the aquifer with substances used in the agricultural and

commercial land uses above.

Two other wells, Pugnado #2 and Vega Baja #3, both in the Cibuco
River basin (northern aquifer), and both in spatial association with
residential land use, had lead measuraments of 22.5 ug/l and 20.7 ug/l
respectively during the second sampling. Readings obtained during the
first sampling activity were of 0.8 and 0.7 ug/l, respectively. Although the
current standard for lead in drinking water is of 50.0 ug/l, U.S.E.P.A.
admits that this standard is obsolete. The proposed standard is a reduction
to a maximum concentration of 20.0 ug/l but, according to some experts,

even this concentration is not safe for human consumption.

Trace levels of mercaptobenzothiazole (1.0 ug/l), and petroleum
derivated hydrocarbons (3.4 ug/l) were also detected at the well Vega Baja
#3 during the third sampling activity. Although in relatively small
concentrations, the presence in groundwater of chemical substances such
as these questions the quality of the groundwater reservoir The slow
movement and long storage in groundwater systems makes them more
consistent in quantity and quality that surface water. Because of restricted

movement, they respond more slowly to pollution, often requiring years for

108

pollutants to travel through aquifers to points of use. However, once
pollution has reached the point of use, that same slow movement may
require a very long time to clean the aquifer after pollution emissions have

stopped.

Biochemical oxygen demand is not a parameter in the regulation for
potable water, but one of the wells in the Guayanés River basin, surrounded
by sugarcane cultivation and a sugarmill industry, exceded the BOD
standard of 5.0 ml/l (5000.0 ug/l). In the first sample a measurement of 5.2
ml/l was obtained, and in the second sample it was of 7.5 ml/l. This being a
well in a sugarcane field, it is possible for fertilizers and pesticides to
percolate and reach the groundwater aquifer. Fertilizers, herbicides and
insecticides, in addition to being a source of toxic compounds, can also
contribute to the BOD of the receiving waters. Moreover, the BOD-5 of
wastes from the sugarmill industry can be very high. Wastes from the beet
sugar refining and from molasses distilling have a BOD-5 of 450-2000 mg/l
and of 20,000-30,000 mg/l repectively. If wastes are not disposed of
adequately they might reach the aquifer. However, monitoring of BOD-5 in
waterbodies is not motivated by concern about public health impacts of
discharges. It has never been demonstrated that there is any relationship
between the dissolved oxygen content of water and the health of persons

drinking or otherwise contacting it.

All wells had detectable concentrations of arsenic. The drinking
water regulation for arsenic is 50.0 ug/l, which is the same numerical limit
set for untreated surface waters. However, the new standard for arsenic in
groundwater is of 0.022 ug/l. Comparisons made between this standard

and the concentrations detected in well samples during the first and/or

109

second sampling, reveal that all wells have concentrations above the new

standard limit.

For three of the samples, arsenic concentrations were circa 0.1 ug/l,
which is 4.5 times the numerical limit set by the new standard. A revision
of the method of analysis and the sensitivity of the instrument is therefore

necessary for the detection of arsenic in groundwater samples.

Literature reports that inorganic arsenic compounds can produce
toxic effects in a large number of organs. Acute and subacute effects
appear in adults after ingestion of a few micrograms daily. Similar doses
may result in severe intoxication and even death in infants. Chronic effects
in many organ systems may also result from exposure to inorganic arsenic
compounds. Among the noncarcinogenic effects are hyperkeratosis, portal
hypertension, and disturbances of the peripheral vascular and nervous
system. These effects have mostly been encountered following exposure to
inorganic arsenic, either in drinking water or in drugs. Moreover, an
increased frequency of skin cancer has been observed in people exposed to
inorganic arsenic in drinking water and trivalent inorganic arsenic in

drugs.

All forms of land use, including agriculture and livestock are
associated with elevated levels of water contamination. Discharge from
sewage plants is particularly onerous. Industry, as expected, is a major
hazard, but residential land use, that is, urbanization with non-point
sources of pollution, is also a major contributor. Given the crowding and

multiplicity of land uses, the threats to water purity seem to be ubiquitous.

CHAPTER VI

CONCLUSIONS AND RECOMMENDATIONS

Waterbodies in spatial association with all six types of land use
considered in this study presented detectable concentrations for the water
quality parameters tested. Regardless of the intermittency at which the
samples were collected, these substances were found at high enough
concentrations to be detected during laboratory analysis. Hence, our broad
postulated relationship that different land uses contribute to the pollutant

loads of waterbodies from point and nonpoint sources can be accepted. ,

As a general caveat it should be pointed out that the interpretation of
the laboratory results were like "snapshots" of the quality of the water
sampled. It has been stated before that the method of sampling employed
in this study serves to provide an indication of the quality of the waterbody
sampled only at the time the sample is collected and thus a detectable
concentration of a particular substance that is released intermittently may
or may not be present at the time the sample is collected. This is
particularly relevant for water samples taken from surface waterbodies

where the movement of the flow of water is quicker than in groundwater.

Variation was observed among all maximum concentrations of
parameters per land use, the only exceptions being those for total and fecal
coliform. Regarding this parameter, we agree with the recommendations
made by others on the need to develop a better method for the identification

of the pollution of tropical waters with disease-causing microorganisms.

110

111

The coliform standard is not absolute and it does not entirely exclude the
possibility of acquiring an intestinal bacterial infection and does not provide
protection against viral diseases. It should be noted that while the World
Health Organization has established international guidelines for coliform
colony counts, these guidelines were stated only as general rules.
Individual countries can develop their own national standards using their
own risk/benefit criteria and taking into account their own particular

circumstances.

Regarding the other water quality parameters, the maximum
concentrations may be indicative of the type of substances to expect in
association with the particular land uses. As noted, a maximum
concentration detected does not necessarily imply that the water quality
standard for that particular parameter was violated. However, it does

indicate a potential to exceed the standard limit in the waterbody sampled.

Some of the persistent organics in existence today are objectionable
because of known harmful effects on humans, fish, or wildlife. Others are
considered objectionable because of adverse effects that are suspected but
whose nature and extent are unclear now. This problem is different in
character and dimensions from the concerns about oxygen demand and
dissolved oxygen levels in waterbodies, which have represented the

principal pollution control objective until now.

The relevance of the detection of semi-volatile organic compounds in
the water samples, surface and underground, can be interpreted from
differents points of view. With few exceptions, most of the concentrations of

the detected compounds were below 1 part per billion, which can be

112

considered as a minor insult to the quality of the waters. On the other
hand, a substantial portion of these substances are either classified as toxic
substance and/or priority pollutants, and thus are subject to regulation.
But no water quality standard regulation exists for them. If these waters
were to be treated for potable supply, it is not certain that the contaminant
substances could be removed. Furthermore, the potential health hazards
are unknown, particularly when they occur in combination. In those
circumstances not only additive, but the possible synergistic effects must be

considered.

A concern for the presence of toxic compounds relies on the fact that
various toxicants can invade the water cycle from sources such as
manufacturing, agricultural, commercial and household activities.
Neither water nor waste water treatment systems have traditionally been
designed for the removal of toxic materials and monitoring of such

materials has not been generally performed.

(Toxic compounds that are not removed by the standard methods of
treatment should be prevented from reaching water resources. Where
such compounds do appear in waste waters, additional treatment (tertiary
or advanced) must be designed for removal of the specific compounds in a

particular eflluent before its discharge to the water resource is permitted)

The nonmetallic element arsenic, was present in almost all samples
from groundwater from sites surrounded by residential, agricultural and
industrial land uses. The concentration of arsenic in these samples were
above the new arsenic standard for groundwater (0.022 ug/l), but below the
limit set by the drinking water regulation (50.0 ug/l). This standard was

 

113

set on recommendations by U.S.E.P.A. based on state-of-the-art information
on the environmental effects of pollutants on ambient waters and the
human health risk from the potential toxic effects through ingestion of
contaminated waters or organisms. Health authorities must consider an
evaluation of the health impacts that may have occurred or that have the
potential to occur in those communities where the drinking water supplies
are mainly from groundwater, and where concentrations of arsenic have
been detected at above standard limits. As chlorination is the only
purification treatment that groundwater receives prior to distribution for
public consumption, a revision of the water quality standards for potable
supplies must be in order as well as a survey of those wells used for potable

water supply that do not comply with the new arsenic standard.

For an effective implementation of a water quality control program it
is necessary to define clearly the goals or the requirements of a regulation.
Without common standards and terminology among the regulatory
agencies, water quality conditions cannot not be described in meaningful
ways. Moreover, enforcement is hampered because it is difficult to prove
violations of the laws and regulations. It is also difficult to identify water

quality trends and evaluate progress in pollution control programs.

Most of the monitoring done to assess the effectiveness of water
quality programs is usually directed to gross pollution parameters, such as
turbidity, color, BOD, and suspended solids. Only in some circumstances
are monitoring activities conducted for specific constituents, such as
metals and organics. Generally these are done in connection with specific
industrial discharges, or in water supplies where there are special

grounds for concern. As more specific chemicals are defined in water

114

quality standards, there will be an increased need for developing

monitoring methods for those substances.

It is worth noting that while no pesticide was detected in surface
water samples, particularly from crop production activities, two of the wells
sampled did have traces of such substances. The capacity of a surface
waterbody to cleanse itself of contaminants contrasts here with the
accumulation potential of toxic substances in groundwater. This is
particularly important since mercury, and notably arsenic, were detected
at concentrations above standard limits according to either the

groundwater or drinking water regulations.

Drainage projects, groundwater pollution, and pumpage from wells
may reduce the potential long-term availability of groundwater. Although
none of the aquifers in the island are areally extensive, their operation and
patterns of flow are generally not simple. For most of the aquifer systems,
the physical properties and recharge rates, withdrawal rates, and
boundary conditions are insufficiently known. Water movement through
limestone may be extremely fast, so that groundwater can be similar to
surface water in relation to contaminants. Rates of contaminant
movement are based on groundwater flow rates, chemical interactions with
aquifer materials, and changes in water chemistry. Thus, it is necessary
to know the local hydrogeology in order to define paths of probable
contaminant movement. Under the right conditions and given enough
time, contaminating fluids that have reached an aquifer can move great

distances, hidden from view and little changed in toxicity.

115

Since we live in an environment with multiple exposure to pollutant
sources there is a vast number of pollutants and several routes of exposure.
Water is only one route by which persons may be exposed to toxic
chemicals. Personal habits, such as dietary preferences, alcohol
consumption, tobacco smoking, and drug use further complicate efforts to

predict pollution hazards and quantify human risk.

There have been few valid epidemiological surveys of populations
relative to multiple chemical exposure. One of the most critical problems
is defining exposure of the individual. Clinical nonspecificity makes it
difficult to distinguish an effect or disease of one etiology from the same
effect or disease caused by another. The problem of latency further
complicates the situation because most of the health effects of concern
appear only after chronic exposure, and clinical signs and symptoms may
appear years after the exposure has ceased to exist.

When these compounds appear in the environment in diverse
combinations, in a variety of media, and often in quantities so small that
are difficult to analyze, it can be overwhelming to try to establish their toxic
potential. The effect of a pollutant mixture cannot be reliably predicted by
summing the toxicity of its individual components, even when these are
known. For example, there is evidence that the apparent reductions in the
toxicity of a metal in increasingly hard water may not be so great when
other metals are concurrently present (Comaby, 1981). Thus, any leniency
that would be granted in water quality objectives for single heavy metals in
hard waters may not be applicable if other heavy metals are present at the

same time.

116

It is difficult to design a study which could establish a cause and
effect relationship between a pollutant and clinical manifestations because
of the various possible causes that can be implicated and the variations in
the degree of exposure or dose. But the presence or lack of association
between contaminants and clinical conditions can be explored. The lack of
evidence to support or negate a causal relationship should not be taken as a
reason to ignore the presence of a contaminant in the environment until

further evidence is documented.

By epidemiologic standards, the exposure levels of most populations
cannot be estimated and probably are relatively small. In addition,
exposure scenarios vary from site to site. A complete understanding of
disease causation should consider not only the question of what causes the
disease in an individual, but also what causes differences between units at

different geographical scales.

The growing recognition of the role of multiple exposures on overall
human health calls for study of the interactive (additive, synergistic, and
antagonistic) effects caused by multiple exposures to pollutant agents and
physical factors in the environment. It has been said that in evaluating
health hazards, contributions must be considered in the context of the total
exposure received by an individual from all sources. In setting maximum
allowable concentrations of chemicals in drinking water, for example,
dosages normally received through other routes must be considered, and
the amounts that might otherwise be permitted in the water must be

reduced (Draggan et al, 1987).

117

The dynamics of pollutants in the environment are not well
understood. For instance, effluent limits are a mechanism for placing
specific numerical limits on multiple sources of wastes entering a water
body. In the case of surface water contamination control, effluent limits
are placed on point-source discharges, but for ground water contamination
control, effluent limits should apply to a much broader range of activities,
such as limits on types of materials disposed of in sanitary landfills, limits
on specific contaminants injected into an aquifer by mean of a disposal well

and pollutant discharge limitations for surface impoundments.

Environmental regulators cannot delay regulating a suspected
harmful exposure until scientific consensus exists. In instances like this,
decision-making under conditions of uncertainty is necessary. Research
on the effectiveness of various preventive strategies is necessary. Detection
of new causes of environmental disease is not an end in itself; prevention is

the ultimate goal of environmental health research.

APPENDIX A

Description of Water Quality Analyses

DESCRIPTION OF WATER QUALITY ANALYSES

Total and Fecal Coliforms (MPN)

The standard procedure for this method is that culture from positive
tubes of the lauryl tryptose broth is inoculated into Escherichia coli (EC)
broth and incubated at 44.5 C for 24 hours. Formation of gas in any quantity
in the inverted vial is a positive reaction confirming fecal coliforms.
Coliform densities are then calculated from the MPN table on the basis of
the positive EC tubes (EPA, Microbiological Manual, 1978).

These tables can be used for a number of sample volumes and
replicates of samples volumes. The numbers of coliform group bacteria in
a water sample can be thus determined based upon the observed
combination of positive and negative fermentation tube results. The 95 per
cent confidence limit is provided for each estimate value in the MPN tables.

BOD-5

The oxygen uptake at 5 days of incubation at a test temperature of 20
Celcius degrees is the standard BOD. The test measures the quantity of
oxygen utilized by chemical or biological reactions over a 5 day period.
Thus, the degree of organic pollution can be determined. If the BOD
reaches the point where aerobic microorganisms (those requiring
molecular oxygen for metabolic processes) cannot survive, anaerobic forms
(those that grow in the absence of molecular oxygen) become predominant,
producing materials that decrease water quality (Guthrie and Perry, 1980).

118

119

Heavy Metals (atomic absorption)

A sample is aspirated into a flame and atomized and a light beam is
directed through the flame, into a monochromator, and on to a detector that
measures the amount of light absorbed by the atomized element in the
flame. The amount of energy of the characteristic wavelenght absorbed in
the flame is proportional to the concentration of the element in the sample.
Special procedures are necessary in order to prepare the metal in a form

and concentration suitable for atomization (Standard Methods, 1985).
Total Kieldahl Nitrogen

In the presence of H2804, potassium sulfate (K2804), and mercuric
sulfate (HgSO4) catalyst, amino nitrogen of many organic materials is
converted to ammonium sulfate [(NH4)2SO4)]. Free ammonia and
ammonium-nitrogen also are converted to (NH4)2SO4. During sample
digestion, a mercury ammonium complex is formed and then decomposed
by sodium thiosulfate (NazSan). After decomposition the ammonia is
distilled from an alkaline medium and absorbed in boric or sulfuric acid.
The ammonia is determinedd colorimetrically or by titration with a

standard mineral acid.
Semi-Volatile Organic Compounds

The analyses of the pollutant depends upon its physical removal from
the sample medium. This process is called extraction and involves
bringing a suitable solvent into contact with the sample, this can be
accomplished by shaking the water sample and solvent in a separatory

funnel and then allowing it to separate into two layers, water and solvent.

120

The extracted pollutant must be concentrated to a small volume
(approximately 5-10mL). This was accomplished by removal of the solvent
by evaporation under vacuum. This was further concentrated to 1 mL by

evaporation under a stream of nitrogen.

Once the pollutant was extracted and separated from the sample
water, the actual identification procedure began. Recent advances have
allowed sensitive measuraments at the parts per billion and parts per
trillion levels for many pollutants. Many toxic materials present in minute
quantities could not be detected until technological advances reached the
present state of the art. At present most environmental pollutants are
identified and quantified by gas chromatography/mass spectrometry
(GC/MS). After the organics in a sample have been isolated and
concentrated, they are separated on a gas chromatograph, and detected and

quantified with the mass spectrometer.

Chromatography. All chromatographic processes utilize an inmobile and
a mobile phase to effect a separation of components. The mobile phase can

be a liquid or gas, whereas the immobile phase can be a liquid or solid.

The essential components of a gas chromatograph (GC) consist of an
injector port, oven, detector amplifier. Contained within the oven is a
column filled or coated with the immobile phase. The mobile phase is an
inert gas (called a carrier gas) such as helium, which passes through the

column.

When a sample is introduced into a heated chamber through a
silicone rubber septum with hypodermic syringe the temperature is enough

to vaporize .the sample components. The components separate and are

121

swept through the column by the carrier gas to the detector which sends a
signal to a recorder. The gas chromatograph is an excellent separator, but
it is not a good analytical tool. Identification of the compound could not be
based only on retention time because it depends on many other factors in

addition to the nature of the compound.

Spectroscopy. Is a method concerned with the changes in atoms and
molecules when electromagnetic radiation is adsorbed or emitted.
Instruments have been designed to detect these changes. In pollution
analysis mass spectroscopy (MS) is used widely for the identification of
compounds. MS is a highly sensitive detector for a GC since it can be

interfaced to the MS.

The GC is used to separate individual components as previously
described. The column effluent them to the MS, where it is bombarded by
an electron beam. Electrons are removed by this process, and the ions
produced are accelerated. After acceleration, they pass through a
magnetic field, where the ion species are separated by the different
curvatures of their paths under gravity. Normally, only positive ions are
detected. The resulting pattern is characteristic of the molecule under
study. By interfacing the detector with a computer system, data analysis
and quantitation are performed automatically.

Qualitative identification of the parameters in the sample extract is
performed using the retention time and the relative abundance of three

characteristic masses. The compounds were identified by consulting the

W by Stenhagen. Abrahamsson and
McLafferty. and the WW

122

Quantitative analysis were performed by using anthracene and
tetradecane as standards in calibration curves. Each of these two
compounds represents a family of chemical compounds. The more
accurate quantitation method is that one in which a calibration curve is
developed using a standard identical to the compound being measured.
This is virtually impossible in a study such as this one in which there is no
previous knowledge of the compounds being detected, and where the
number of compounds to be quantized would imply the creation of
numerous calibration curves. Instead calibration curves are created with
standards that represent families of chemical compounds and an
assumption is made that the compound being measured behaved similar to

the standard selected during the GC/MS analysis.

APPENDIX B

Detected Semi-Volatile Organic Compounds By Hydrological Basin

123

Cibuco River Basin - First Sampling

 

Concentration
(PPB)

—-

Sampling Site Compound

-

1. Morovis River

2. Hicatea Creek

 

_ — q— _ — —
—

3. Cienaga Prieta Channel

 

4. Cibuco River

 

5. Corozal River

 

6. De los Negros River

 

7. Mavilla River N0! identified 1.3

u— — _ q- — _ —b — - I

 

8. Pugnado #2 Well

 

Sulfur (octalhione)
88 CAS 10544-50-0

9. Vega Baja #3 Well 0.6

— — — — db — — up — — -b

10. Sabana Hoyos 1 Well

 

qr — — — —

11. Vega Alta 1 Well

F—

12. Spring

Hydrocarbon | 0.2

 

Cibuco River Basin - Second Sampling

 

 

 

 

 

 

 

 

 

l 1

Sampling Station I Compound I flaggmbn
l l

1. Morovis River | Hydrocarbons | 0.5

2. Hicatea Creek I I

3. Cienaga Prieta I I

Channel I I

4. Cibuco River | l
l l

5. Corozal River | l

6. De los Negros River : :

7. Mavilla River | Not identified 0.2

8. Pugnado #2 Well ' Hydrocarbons 0.2
I

 

9. Vega Baja #3 Well

 

10. Sabana Hoyos 1 Well I

 

11. Vega Alta 1 Well

 

12. Spring

Cibuco River Basin - Third Sampling

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

. . I I Concentration
Sampling Site I Compound I (PPB)
1. Morovis River I I
2. Hicatea Creek I Not identified I 0.2

l l
1 Phthalate I 0.1
3' Cienaga Prieta | Not identified | 0.1
Channel
. . T i
4. ClbUCO Rlver Hydrocarbons l 0.2
l
5. Corozal River I I
D lo N F - ~ I
5- e S 99’05 Not Identified 0-2
River I I
7. Mavilla River I I
8. Pugnado #2 Well I Phthalate I 0.1
l
9. Vega Baja #3 We!” 2-Mercaptobenzothiazole I 1.0
C7H5NSZ CAS 149-30-4 1
I Hydrocarbons I 3.4
10. Sabana Hoyos1 l Hydrocarbon | 0.1
well I l
11. Vega Alta 1 Well I Benzyl butylphthalate I 0.2
I C19H2004 CAS 85-68-71
I Hydrocarbon I 0.2
12_ Spring | Benzyl butyl phthalate | 0.2
I l

019H2004 CAS 85-68-7

 

126

Guayanés River Basin - First Sampling

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

l I n i n
Sampling Station I Compound I C‘IP‘I’fgII'a‘ °
1. Limones River I Hydrocarbon I 0.5
2. Rio Guayanés I I
I l
3. Aguas Largas Creek I Not identified l 0.1
4. Guayanés River I NOt identified I 0.2
5. Cafio Santiago Trib.I SS£I3IIIUI (waCIlItcScarthIM-So-o I 5.3
I Hydrocarbon I 0.4
| Not identified I 2.0
| Diethyl phthalate I 0.4
| C12H1404 CAS 84-66-2 |
6. Cafio Santiago I Diethyl phthalate I 0.2
C12H1404 CAS 84-66-2
I 2.6-dileilbutyl—p-methyl phenol I 0.1
I Terpenoid compound I 0.1
7. Del Ingenio River ' '
Tributary I I
8. Aguacate Creek I Hydrocarbons l 1.0
9. Cafio Santiago I Diethyl phthalate I 0.1
I C12H1404 CAS 84-66-2 I
I Not identified I 0-1
10. Guayanés River I Hydrocarbons I 2.5
I
11. La Gnia Well I Hydrocarbons I 0.5
I Not identified I 0.2
I Phthalate I 0-2
12. Roig Nuevo Well I Di-n-butyl-phthalate I 44
C16H2204 CAS 84-74-2 I
I Not identified I 0.2

 

127

Guayanés River Basin - Second Sampling

 

 

 

I IConcentration
' Com ound
Sampllng Station J P (PPB)
1. Limones River I
2. Guayanés River I Phthalate 0.2

 

3. Aguas Largas Creek Caproiactam Hexanoic acid.6-amino 0.8
C6H11NO 06H13NO

ICAS 00105-60-2 2 CAS 60-32-2

 

4. Guayanés River I Hexanediodic acid. mono(2-ethylhexyl)ester 2_4

| C14H2604 CAS 04337-65-9

 

I Dodecanamide, N, Glycine, N-methyl-N-
N-bis (1 -oxododecyl)
(2-hydroxyethyl) C15H29N03

I C16H33N03 97-78-9

I CAS 00120-40-1

0.2

 

 

I Lauric acid (N-dodecanoic acid)
J 012H2402

5. Cafio Santiago Trib. I

1.7

 

I S8 CAS 10544-50-0 0'1

7. Del Ingenio River
tributary

8. Aguacate Creek

9. Cafio Santiago

 

— — .- — — .- _ — ‘- _ - — _ - — _ — — - — — —

10. Guayanés River

 

11. La Gnia Well

12. Roig Nuevo Well | |

 

128

Guayanés River Basin - Third Sampling

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

I | Con ntra ’ n
Sampling Station I Compound I “$93) IIO
1. Limones River I I
2. Guayanés River I I
3. Aguas Largas CreekI Hydrocarbons I 0.8
4. Guayanés River I Not identified I 0.1
5. Cam Santiago Trib.I Sulfur I
I 38 CAS 10544-50-0 I 3.7
I Anthracene I
. C14H10 CAS 120-12-7 . 0-3
I Phthalate I 05
I Fluoranthene I
. C16H10 CAS 206-44-0 I 0.2
l l
I 9,10-Diphenylphenanthrene I 0.1
I Not identified I 0.3
I Hydrocarbon I 0.5
6. Caho Santiago ' Palmitic acid (Hexadecanoic acid) I 03
' [4-Acetoxy-6-Methyl-2-Pyridone I 0 3
I CBH903 CAS 05-749—2] I '
I Not identified I 0-1
I Diethyl phthalate I 0.1
I C12H1404 CAS 84-66-2 .
I Sulfur (octathiocane) I 0.4
I 88 CAS 10544-50-0 |
I Hydrocarbons I 0.5
7. Del Ingenio River | I
tributary I I
8. Aguacate Creek I I
9. Cafio Santiago I Phthalate I 0.1
10. Guayanés River I l
11. La Gnia Well I Benzyl butyl phthalate I 0.2
C19H2004 CAS 85-68-7
12. Roig Nuevo Well I Benzyl butyl phthalate I 0.3
l

C19H2004 CAS 85-68-7

 

Yagiiez River Basin - First Sampling

 

 

 

'00

Sam lin Station Com ound ncentration
P 9 P (PPB)

1. Marini Well

2. Cam Boquilla Phthalate 0.4

 

3. Yaguez River

 

4. Sébalos Creek

 

 

— 4. — _ — — — — _ _

 

 

 

 

 

 

 

 

 

 

 

5. Grande Creek Hexanediodic acid, mono 0_1
(2-ethyihexyi)ester
C14H2604 CAS 0437-65-9
6. Yagt'iez River I
7. Majagual Creek IHydrazine,1,1-diphenyl-2-(2.4,6- 9.1
trinitrophenyl) I
I 01 8H13N506 CAS 01707-75-1 I
I Dodecanamide, N Decanamide, N- |
(2-hydroxyethyl) (2-hydroxyethyl) 7'3
I C14H29N02 C12H25N02 I
I CAS 00120-40-1 CAS 7726-08-1 I
1-Aminonaphthalene I
I 016 H13 N CAS oooeo-ao-z I 6-3
I Pyridine,4-(phenylmethyl) I 01
l C12H11N CAS 2116-65-6 I ' ~
I Hydrocarbon (octadaceno) I 3.0
I Hydrocarbon (hexadeceno) I 7.3
| Not identified | 0.2
I Not identified | 1.1
| Phthalates [Bis-(2-ethylhexyl) phthalate] | 5.3
8. Canas River I I
9. Canas River IPyridine,4-(phenyl Benzenamine. N-phenyl I 02
I methyl) C12H11N I
012H11N CAS 122-39-4
|

ICAS 2116-65-6

 

 

130

Yaguez River Basin - Second Sampling

 

Sampling Station

1.

Marini Well

Compound

Concentration
(PPB)

 

Boquilla Creek

. Yaguez River

 

Sébalos Creek

 

Grande Creek

— — — .h — — — _

_ — _ uh _ - — —

 

Yagiiez River

 

Majagual Creek

Hydrocarbons

1.0

 

Callas River

d_ _ - — -b

 

. Canas River

_ +— d _ — --

 

131

Yagiiez River Basin - Third Sampling

 

 

 

 

 

Sampling Station Compound ngggItration
1. MariniWell

2. Boquilla Creek

3. Yagl'iez River

4. Sébalos Creek Hydrocarbon 1.1

 

5. Grande Creek

 

6. Yagiiez River

 

7. Majagual Creek

 

8. Canas River

 

9. Canas River

 

 

 

Ca

C2

C1

BIBLIOGRAPHY

American Public Health Association, 1985, Standard Methods for the
Examination of Water and Wastewater, sixteenth edition, APHA,
AWWA, WPCF, Washington, D.C..

Anderson , A.C., Abdelghani, A.A., 1985, "Fate of Foreing Compounds in
the Environment", Journal of Community Health, Vol.10, No.3, pp.
172-179.

Calabrese, Edward J ., 1987, "Animal Extrapolation, a Look Inside the
Toxicologist's Black Box", Environmental Science and Technology,
Vol. 21, No. 7, pp. 618-623.

Canter, Larry W., 1985, River Water Quality Monitoring, Lewis Publishers,
Inc. Chelsea, Michigan.

Chau, Alfred S.Y., B.F. Afghan, 1982, Analyses of Pesticides in Water,
Volume III, Nitrogen-Containing Pesticides, CRC Press, Inc., Boca
Raton, Florida.

Chiras, Daniel D., 1985, Environmental Science, A Framework for Decision
Making, The Benjamin/Cummings Publishing Company,Inc.,
Menlo Park, California. '

Clarkson, Thomas W., 1979, "Effects - General Principles Underlying the
Toxic Action of Metals", Handbook on the Toxicology of Metals, Lars
Friberg et a1 (editors), Elsevier/ North Holland Biomedical Press.

Code of Federal Regulations, 1979, Vol. 40, Parts 100-149, pp. 442-456.

Conacher, Dufl‘, 1988, Troubled Waters on Tap, Center for Study of
Responsive Law

Comaby, Barney W. (editor), 1981, Management of Toxic Substances in Our
Ecosystems, Ann Arbor Science, Publishers Inc.

Cruz, Angel D., 1988, "Geografi’a Economica", Elementos de Geografia de
Puerto Rico, Librotex, Inc., Puerto Rico.

Cyr, F., C. Mehra, V.N. Mallet, 1987, "Leaching of Chemical
Contaminants from a Municipal Landfill Site", Bulletin of
Environmental Contamination and Toxicology, Vol. 38, pp. 775-782.

Draggan, Sidney, John J. Cohrssen, Richard E. Morrison (editors), 1987,

Environmental Impacts on Human Health, Praeger Publishers, New
York.

132

133

Greenberg, Michael R. (editor), 1987, Public Health and the Environment,
The Unites States Experience, The Guilford Press, New York,
London.

Greenberg, M., Anderson, R., Keene, J ., Kennedy, A., Page, G.W.,
Schowgurow, S., 1982, "Empirical test of the Association Between
Gross Contamination of Wells with Toxic Substances and
SuI'rounding Land Use", Environmental Science and Technology,
Vo . 16, No. 1.

Guthrie, Frank E., Jerome J. Perry, 1980, Introduction to Environmental
Toxicology, Elsevier North Holland Inc., New York.

Einar Stenhagen, Sixten Abrahamsson, Fred W. McLafl‘erty (editors),
Registry of Mass Spectral Data, John Wiley & Sons, Inc.,1974.

Hazen, Terry C., Santiago-Mercado, Jesus, Toranzos, Gary A., Bermudez,
Madeline, 1985, "What Does the Presence of Fecal Coliforms Indicate
in the Waters of Puerto Rico?, A Review", Boletin de la Asociacién
Médica de Puerto Rico, Vol. 79, No. 5, pp.189- 193.

Hem, John D. (editor), 1985, third edition, Study and Interpretation of the
Chemical Characteristics of Natural Water, U.S. Geological Survey
Water-Supply Paper 2254.

Hites, Ronald A., 1987, CRC Handbook of Mass Spectra of Environmental
Contaminants, CRC Press, Inc., Boca Raton, Florida.

Humerik, T.C., M.D. Smolen, S.A. Dressing, 1987, "Pollution From
N onpoint Sources", Environmental Science and Technology, Vol. 21,
No. 8, pp. 737-742.

Kimbrough, Renate D., 1990, "Environmental Protection: Theory and
Practice", Environmental Science and Technology, Vol. 24, No. 10,
pp. 1442-1445.

Landner, Lars (editor), 1989, Chemicals in the Environment, Springer-
Verlag Berlin.

Lioy, Paul J ., 1990, "Assesssing Total Human Exposure to Contaminants",
Environmental Science and Technology, Vol. 24, No.7, pp. 938-945.

Mailman, Richard B., 1980, "Heavy Metals", Introduction to
Environmental Toxicology, Frank E. Guthrie and Jerome J. Perry
(editors), Elsevier North Holland, Inc., New York.

134

Mara, D.D., Oragui, J ., 1985, "Bacteriological Methods for Distinguishing
Between Human and Animal Faecal Pollution of Water: Results of
Fieldwork in Nigeria and Zimbabwe", Bulletin of the World Health
Organization, Vol. 63, No.4, pp. 773-783.

Marrack, David, 1981, Environment and Health, Ann Arbor Science
Publishers, Inc.

Middlediteh, B.S., Missler, S.R., Hines, EB, 1981, Mass Spectrometry of
Priority Pollutants, Plenum Press, New York and London.

National Oceanic and Atmospheric Administration, Climatological Data,
Puerto Rico & Virgin Islands, November 1989, Vol. 35, No. 11.1990.

--- Climatological Data, Puerto Rico & Virgin Island, January 1990, Vol.
36, No. 1.1990.

--- Climatological Data, Puerto Rico & Virgin Island, March 1990, Vol.
36, No.3.

--- Climatological Data, Puerto Rico & Virgin Island, April 1990, Vol.
36, No. 4.

Page, G. William, 1981, "Comparison of Groundwater and Surface Water
for Patterns and Levels of Contamination by Toxic Substances",
Environmental Science and Technology, Vol. 15, No. 12, December.

---1987 , "Water and Health", Public Health and theEnvironment, Michael
R. Greenberg (editor), The Guilford Press, New York, London.

Parrilla, Pedro A., 1977, "Geografi’a Industrial de Puerto Rico", Geovisién
de Puerto Rico, Maria Teresa B. De Galifianes (editor), Editorial
Universitaria, Universidad de Puerto Rico.

Puerto Rico Department of Health, 1979, Drinking Water Regulations,
Regulation Number 50, Commonwealth of Puerto Rico.

Puerto Rico Environmental Quality Board, 1978, Informe Final del Proyecto
208 Isla (draft), Commonwealth of Puerto Rico.

--1988, Goals and Progress of Statevvide Water Quality Management
Planning Puerto Rico 1986-1987, Commonwealth of Puerto Rico,
Office of the Governor.

--1990, Water Quality Standards Regulation (ammended version of 1990),
Commonwealth of Puerto Rico/ Office of the Governor.

135

Raidt, Daniel E., Louis J. Acierno, 1985, "Giardiasis, An Overview of Its
Public Health Significance", Journal of Environmental Health, Vol.
47, No. 6, pp. 297-299.

Travis, Curtis C. and Carolyn B. Doty, 1990, "Can Contaminated Aquifers
at Superfimd Sites be Remediated?", Environmental Science and
Technology, Vol. 24, No. 10, pp 1464-1466.

United States Environmental Protection Agency, Quality Criteria for Water,
1986, Office of Water Regulations and Standards, EPA 440/5-86-001.

United States Geological Survey, 1982, Reconnaissanee of Ground-Water
Quality Throughout Puerto Rico, September-Octoberl981, Water
Resources Division, Open-File Report 82-334.

--1985, Recoinnaissance of Trace-Organic Compounds in
Ground Water Throughout Puerto Rico, Open File Data Report 84-
810.

--1987, Planning Report for the Caribbean Islands Regional Aquifer-
System Analysis Project, Water Resources Investigations, Report 86-
4074.

--1989, Water Resources Data Puerto Rico and the U.S. Virgin Islands,
Water Year 1989, Water Data Report PR-89-1.

Van der Leeden, F., F. L. Troise, D.K. Todd,(editors), 1990, The Water
Encyclopedia, second edition, Lewis Publishers.

Wells, Barbara, 1990, Restrictions Imposed on Contaminated Sites: A
Status of State Actions, National Governors‘ Association.

HICHIGRN STQTE UNIV. LIBRQRIES

n @l w mmun m

 

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