EPA 440/l-76/060n
Group II
Development Document for Interim
Final Effluent Limitations, Guidelines
and Proposed New Source Performance
Standards for the
Hospital
Point Source Category
^ATES ENVIRONMENTAL PROTECTION AGENCY
APRIL 1976
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DEVELOPMENT DOCUMENT
for
INTERIM FINAL
EFFLUENT LIMITATIONS, GUIDELINES
AND PROPOSED NEW SOURCE PERFORMANCE STANDARDS
for the
HOSPITAL POINT SOURCE CATEGORY
Russell E. Train
Admini strator
Andrew W. Breidenbach, Ph.D.
Assistant Administrator
for Water and Hazardous Materials
Eckardt C. Beck
Deputy Assistant Administrator for
Water Planning and Standards
Ernst P. Hall
Acting Director, Effluent Guidelines Division
Joseph S. Vitalis
Project Officer
and
George M. Jett
Assistant Project Officer
April 1976
Effluent Guidelines Division
Office of Water and Hazardous Materials
U.S. Environmental Protection Agency
Washington, D.C. 20460
'H'
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ABSTRACT
This document presents the findings of a study of the
hospital point source category for the purpose of developing
effluent limitations and guidelines for existing point
sources, standards of performance for new point sources and
pretreatment standards for new point sources, to implement
Sections 301(b), 301(c), 304 (b), 304 (c) , 306(b), 306 (c),
307(b) and 307 (c) of the Federal Water Pollution Control
Act, as amended (33 U.S.C. 1251, 1311, 1314(b) and (c),
1316(b) and 1317(b) and (c) , 86 Stat. 816 et. seq.) (the
"Act").
Effluent limitations and guidelines contained herein set
forth the degree of effluent reduction attainable through
the application of the Best Practicable Control Technology
Currently Available (BPT) and the degree of effluent
reduction attainable through the application of the Best
Available Technology Economically Achievable (BAT) which
must be achieved by existing point sources by July 1, 1977,
and July 1, 1983, respectively. The standards of per-
formance and pretreatment standards for new sources
contained herein set forth the degree of effluent reduction
which is achievable through the application of the Best
Available Demonstrated Control Technology (NSPS) , processes,
operating methods, or other alternatives.
The development of data and recommendations in this document
relate to the hospital point source category, which is one
of eight industrial segments of the miscellaneous chemicals
point source category. Effluent limitations were developed
on the basis of the level of raw waste load as well as on
the degree of treatment achievable. Appropriate technology
to achieve these limitations include biological and
physical/chemical treatment and systems for reduction in
pollutant loads.
Supporting data and rationale for development of the
proposed effluent limitations, guidelines and standards of
performance are contained in this report.
111
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TABLE OF CONTENTS
Section Title Paqe
Abstract
Table of Contents
List of Figures
List of Tables
I Conclusions 1
II Recommendations 7
III Introduction 11
IV Industrial Categorization 19
V waste Characterization 23
VI Selection of Pollutant Parameters 29
VII Control and Treatment Technologies H9
VIII cost. Energy, and Non-water Quality
Aspects 55
IX Best Practicable Control Technology
Currently Available (BPT) 67
X Best Available Technology Economically
Achievable (BAT) 71
XI New Source Performance Standards (NSPS) 73
XII Pretreatment Guidelines 75
XIII Performance Factors for Treatment Plant
Operations 79
XIV Acknowledgements 85
XV Bibliography 89
XVI Glossary 99
XVII Abbreviations and Symbols 129
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LIST OF FIGURES
Number Title Page
V-1 Pollutant Raw Waste Load Vs.
Flow Raw Waste Load 2?
VII1-1 BPT cost Model 58
VIII-2 NSPS and BAT Cost Model 62
VII
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LIST OF TABLES
Number
1-1
V-1
V-2
VI- 1
VII -1
VII-2
VIII- 1
VIII-2
VIII-3
IX-1
X-1
XI- 1
XII-1
XIII-1
XVIII
Title Page
Summary Table - Hospital Point
Source Category 1
BPT, NSPS, and BAT Effluent
Limitations Guidelines 8
Raw Waste Loads - Twelve Hospitals 25
Raw Waste Loads - Hospital
Nos. 91, 92 and 93 26
List of Parameters to be Examined 31
Treatment Technology Survey 51
Summary of Historic Treatment
Performance 52
BPT Treatment Systems Design
Summary 59
NSPS Treatment System Design Summary 63
Wastewater Treatment Costs for BPT,
NSPS and EAT Effluent Limitations
(ENR 1780 - August, 1972 Costs) 6H
BPT Effluent Limitations Guidlines 69
BAT Effluewt Limitations Guidelines 72
New Source Performance Standards 74
Pretreatment Unit Operations 78
Effluent Variation of Activated Sludge
Treatment Plants Effluents 82
Metric Table 131
IX
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SECTION I
CONCLUSIONS
General
The miscellaneous chemicals industry encompasses eight
industrial categories grouped together for administrative
purposes. This document provides background information for
the hospital category and represents a revision of a portion
of the initial contractor's draft document issued in
February, 1975.
In that document it was pointed out that each category
differs from the others in raw materials, manufacturing
processes, and final products. Water usage and subsequent
wastewater discharges also vary considerably from category
to category. Consequently, for the purpose of the
development of the effluent limitations, guidelines and
corresponding BPT (Best Practicable Control Technology
Currently Available), NSPS (Best Available Demonstrated
Control Technology) for new sources, and BAT (Best Available
Technology Economically Achievable) requirements, each
category is treated independently.
It should be emphasized that the proposed treatment model
technology will be used only as a guideline. The cost
models for BPT, BAT, and NSPS were developed to facilitate
the economic analysis and should not be construed as the
only technology capable of meeting the effluent limitations,
guidelines and standards of performance presented in this
development document. There are many alternative systems
which, taken either singly or in combination, are capable of
attaining the effluent limitations, guidelines and standards
of performance recommended in this development document.
These alternative choices include:
1. Various types of end-of-pipe wastewater treatment.
2. Various in-plant modifications and installation of
at-source pollution control equipment.
3. Various combinations of end-of-pipe and in-plant
technologies.
It is the intent of this document to identify the technology
that can be used to meet the regulations. This information
also will allow the individual hospital to make the choice
of what specific combination of pollution control measures
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is best suited to its situation in complying with the
limitations, guidelines and standards of performance
presented in this draft development document for the
hospital point source category.
Hospitals
It was determined that the hospital category did not require
further sutcategorization for the purpose of establishing
effluent limitations, guidelines and new source performance
standards. Possible bases for subcategorizaton considered
during the study included size, hospital age, geographic
location, hospital type, nature of wastes generated, and
treatability of wastewaters. It was concluded that hospital
wastewater characteristics are independent of these factors
and that further subcategorization was not justified.
Unlike many industrial plant wastes, sanitary wastes in a
hospital are usually not segregated from other waste
streams. sanitary wastes make up a large portion of the
total wastewater flow and are discharged to a common sewer
system along with other waste streams. Therefore, since
sanitary wastes make up a significant portion of a
hospital's total wastewater effluent, it was decided not to
exclude them from the raw waste load (RWL) values. The
major sources of wastewaters in a hospital are patient
rooms, laundries, cafeterias, surgical suites, laboratories,
and x-ray departments. Wastewaters generated by hospitals
can be characterized as very similar to normal domestic
sewage both in type and concentration. Specific
contaminants which may be present, in addition to those
wastes normally found in domestic wastewaters, include
mercury, silver, barium, beryllium and boron. Various anti-
bacterial constituents (i.e., disinfectants) which may exert
a toxic effect on biological waste treatment processes may
also be present. In addition, radionuclides are released to
the environment via the nuclear medicine pathway in the form
of patient excrement. One radioisotope widely used in
nuclear medicine is iodine-131.
Existing control and treatment technology practiced by
hospitals include some in-house reductions as well as
end-of-pipe treatment. Most hospitals are located in
densely populated areas and discharge their wastes to
municipal sewer systems. However, some do utilize on-site
wastewater treatment systems. Current end-of-pipe
wastewater treatment technology involves biological
treatment. The most common treatment system used is
trickling filters, although activated sludge and aerated
lagoons are also utilized. In-plant pollution abatement
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measures include mercury, barium, and boron reduction
programs and silver recovery systems. Some hospitals which
are experiencing an increased use of radiopharmaceuticals
have implemented procedures to hold urine excreted from
patients in order for the isotopes to decay.
Effluent limitations, guidelines and new source performance
standards have been proposed for two wastewater parameters:
Biochemical Oxygen Demand (BOD5) and Total Suspended Solids
(TSS). The choice of these parameters reflects the fact
that organic oxygen-demanding material is the major
contaminant in wastewaters generated by hospitals. Other
possible RWL parameters (mercury, cyanide, nitrogen,
chlorides, beryllium, etc.) were studied during the
project, but were found to be present in concentrations
substantially lower than those which would require
specialized end-of-pipe treatment.
It was concluded that the model BPT waste treatment
technology for the hospitals category should consist of a
biological treatment system with sludge-handling facilites.
The sludge-disposal system would generally consist of
aerobic digestion, vacuum filtration, and ultimate disposal
in a sanitary landfill. Since sludge disposal may create
some long-term groundwater pollution hazard, the preferable
method is to reduce BOD in an aerobic composting operation
before sanitary landfilling. It is emphasized that the
proposed model technology should be used only as a guide and
may not be the most suitable in every situation. The model
NSPS and EAT treatment facility for hospitals consists of
BPT technology followed by filtration.
The specific pollutant effluent limitations are based on the
capacity of the hospital measured in terms of the number of
occupied beds. An individual limitation is established for
a hospital by multiplying the size of the facility (in
thousands of occupied beds) by the pollutant effluent
limitations specified. Since the effluent limitations are
expressed in pounds of pollutant per thousand beds occupied,
this multiplication gives the long-term average daily
discharge value for the hospital. An appropriate
performance factor is applied to obtain maximum average of
daily values for any period of thirty consecutive days and
maximum value for any one day for the effluent limitations.
These performance factors allow for variation in treatment
plant performance and sampling frequency and are necessary
for a meaningful basis for subsequent spot checking or
possible enforcement action. These performance factors are
developed from the historical operation data from several
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exemplary end-of-pipe biological treatment plants for
hospitals.
Table 1-1 summarizes the contaminants of interest, raw waste
loads, and recommended treatment technologies for BPT, BAT,
and NSPS for hospitals. Long-term average daily effluents
are indicated for BPT, BAT and NSPS control technologies.
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SECTION II
R ECOMM ENDATIONS
General
The recommendations for effluent limitations and guidelines
commensurate with the BPT and end-of-pipe treatment
technology for BPT and BAT are presented in the following
text. The NSPS for new sources includes the most exemplary
process controls. The recommendations for effluent
limitations and end-of-pipe treatment technology for NSPS
are given in this text for the hospital point source
category.
Hospitals
Effluent limitations and guidelines commensurate with BPT,
NSPS, and BAT treatment technology are proposed for the
hospital category and are presented in Table II-1. These
effluent limitations, guidelines and new source performance
standards are based on the maximum average of daily values
for thirty consecutive days and the maximum for any one day
and are developed using the performance factors for the
treatment plant operation as discussed in Section XIII of
this development document.
Wastewaters subject to these limitations include the total
combined wastewater stream generated by a hospital facility.
End-of-pipe treatment technologies equivalent to biological
treatment should be applied to the wastewaters from hospital
facilities to achieve BPT effluent limitations. In
addition, to minimize capital expenditures for end-of-pipe
wastewater treatment facilities, BPT technology includes the
maximum utilization of current in-house pollution abatement
methods presently practiced by hospitals.
To meet NSPS and BAT limitations, guidelines and new source
performance standards, end-of-pipe treatment technologies
equivalent to biological treatment followed by multi-media
filtration is recommended. NSPS and BAT treatment
technologies also include the use of the most exemplary in-
house pollution abatement measures and the improvement of
existing in-house measures.
Approximately ninety-two (92) percent of hospital facilities
discharge their effluents to municipal sewer systems.
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Although organic material is the predominant pollutant in
these wastewaters, mercury, barium, boron, silver, and
various solvents may also be present. These should be
recovered by in-house techniques in order to eliminate them
from the raw waste load. Radioactive waste should be
contained and held until safe to be released to the
environment. The permit writers should address these
parameters and other toxic or hazardous materials in the
permit on a case by case basis depending on the amount of
each material in the discharge.
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SECTION III
INTRODUCTION
Purpose and Authority
The Federal Water Pollution Control Act Amendments of 1972
(the Act) made a number of fundamental changes in the
approach to achieving clean water. One of the most
significant changes was to shift from a reliance on effluent
limitations related to water quality to a direct control of
effluents through the establishment of technology-based
effluent limitations to form an additional basis, as a
minimum, for issuance of discharge permits.
The Act requires EPA to establish guidelines for technology-
based effluent limitations which must be achieved by point
sources of discharges into the navigable waters of the
United States. Section 301(b) of the Act requires the
achievement by not later than July 1, 1977 of effluent
limitations for point sources, other than publicly owned
treatment works, which are based on the application of the
BPT as defined by the Administrator pursuant to Section
304 (b) of the Act. Section 301 (b) also requires the
achievement by not later than July 1, 1983 of effluent
limitations for point sources, other than publicly owned
treatment works, which are based on the application of the
BAT, resulting in progress toward the national goal of
eliminating the discharge of all pollutants, as determined
in accordance with regulations issued by the Administrator
pursuant to Section 304(b) of the Act. Section 306 of the
Act requires the achievement by new sources of federal
standards of performance providing for the control of the
discharge of pollutants, which reflects the greatest degree
of effluent reduction which the Administrator determines to
be achievable through the application of the NSPS process,
operating methods, or other alternatives, including, where
practicable, a standard permitting no discharge of
pollutants.
Section 304 (b) of the Act requires the Administrator to
publish regulations based on the degree of effluent
reduction attainable through the application of the BPT and
the best control measures and practices achievable,
including treatment techniques, process and procedure
innovations, operation methods, and other alternatives. The
regulations proposed herein set forth effluent limitations
pursuant to Section 304 (b) of the Act for the hospital point
source category. Section 304 (c) of the Act requires the
11
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Administrator to issue information on the processes,
procedures, or operating methods which result in the
elimination or reduction in the discharge of pollutants to
implement standards of performance under Section 306 of the
Act. Such information is to include technical and other
data, including costs, as are available on alternative
methods of elimination or reduction of the discharge of
pollutants.
Section 306 of the Act requires the Administrator, within
one year after a category of sources is included in a list
published pursuant to Section 306 (b) (1) (A) of the Act, to
propose regulations establishing federal standards of
performance for new sources within such categories. The
Administrator published in the Federal Register of January
16, 1973 (38 F.R. 1624) a list of 27 source categories.
Publication of the list constituted announcement of the
Administrator's intention of establishing, under Section
306, standards of performance applicable to new sources.
Furthermore, Section 307(b) provides that:
1. The Administrator shall, from time to time, publish
proposed regulations establishing pretreatment
standards for introduction of pollutants into
treatment works (as defined in Section 212 of this
Act) which are publicly owned, for those pollutants
which are determined not to be susceptible to
treatment by such treatment works or which would
interfere with the operation of such treatment
works. Not later than ninety days after such
- publication, and after opportunity for public hear-
ing, the Administrator shall promulgate such
pretreatment standards. Pretreatment standards
under this subsection shall specify a time for
compliance not to exceed three years from the date
of promulgation and shall be established to prevent
the discharge of any pollutant through treatment
works (as defined in Section 212 of this Act) which
are publicly owned, which pollutant interferes
with, passes through, or otherwise is incompatible
with such works.
2. The Administrator shall, from time to time, as
control technology, processes, operating methods,
or other alternatives change, revise such
standards, following the procedure established by
this subsection for promulgation of such standards.
12
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3. When proposing or promulgating any pretreatment
standard under this section, the Administrator
shall designate the category or categories of
sources to which such standard shall apply.
4. Nothing in this subsection shall affect any
pretreatment requirement established by any State
or local law not in conflict with any pretreatment
standard established under this subsection.
In order to insure that any source introducing pollutants
into a publicly owned treatment works, which would be a new
source subject to Section 306 if it were to discharge
pollutants, will not cause a violation of the effluent
limitations established for any such treatment works, the
Administrator is required to promulgate pretreatment
standards for the category of such sources simultaneously
with the promulgation of standards of performance under
Section 306 for the equivalent category of new sources.
Such pretreatment standards shall prevent the discharge into
such treatment works of any pollutant which may interfere
with, pass through, or otherwise be incompatible with such
works.
The Act defines a new source to mean any source the
construction of which is commenced after the publication of
proposed regulations prescribing a standard of performance.
Construction means any placement, assembly, or installation
of facilities or equipment (including contractual obliga-
tions to purchase such facilities or equipment) at the
premises where such equipment will be used, including
preparation work at such premises.
Methods Used for Development of the Effluent Limitations and
Standards for Performance
The effluent limitations, guidelines and standards of
performance proposed in this document were developed in the
following manner. The miscellaneous point source category
was first divided into industrial categories, based on the
type of category and products manufactured. Determination
was then made as to whether further subcategorization would
aid in description of the category. Such determinations
were made on the basis of raw materials required, products
manufactured, processes employed, and other factors.
The raw waste characteristics for each category and/or
subcategory were then identified. This included an analysis
of: 1) the source and volume of water used in the process
employed and the sources of wastes and wastewaters in the
13
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plant; and 2) the constituents of all wastewaters
(including toxic constituents) which result in taste, odor,
and color in water or aquatic organisms. The constituents
of wastewaters which should be subject to effluent
limitations, guidelines and standards of performance were
identified.
The full range of control and treatment technologies
existing within each category was identified. This included
an identification of each distinct control and treatment
technology, including both in-plant and end- of-pipe
technologies, which are existent or capable of being
designed for each subcategory. It also included an
identification of the effluent level resulting from the
application of each of the treatment and control
technologies, in terms of the amount of constituents and of
the chemical, physical, and biological characteristics of
pollutants. The problems, limitations, and reliability of
each treatment and control technology and the required
implementation time were also identified. In addition, the
non-water quality environmental impacts (such as the effects
of the application of such technologies upon other pollution
problems, including air, solid waste, radiation, and noise)
were also identified. The energy requirements of each of
the control and treatment technologies were identified, as
well as the cost of the application of such technologies.
The information, as outlined above, was then evaluated in
order to determine what levels of technology constituted the
BPT, BAT, and NSPS. In identifying such technologies,
factors considered included the total cost of application of
technology in relation to the effluent reduction benefits to
be achieved from such application, the age of equipment and
facilities involved, the process employed, the engineering
aspects of the application of various types of control
techniques, process changes, non-water quality environmental
impact (including energy requirements), and other factors.
During the initial phases of the study, an assessment was
made of the availability, adequacy, and usefulness of all
existing data sources. Data on the identity and performance
of wastewater treatment systems were known to be included
in:
1. NPDES permit applications.
2. Self-reporting discharge data from various states.
3. Surveys conducted by trade associations or by
agencies under research and development grants.
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A preliminary analysis of these data indicated an obvious
need for additional information.
The selection of treatment plants was developed from
identifying information available in the NPDES permit
applications, state self-reporting discharge data, and
contacts within the point source category. Every effort was
made to choose facilities where meaningful information on
both treatment facilities and manufacturing processes could
be obtained.
Additional data in the following areas were required; 1)
process raw waste load (RWL) related to production; 2)
currently practiced or potential in-process waste control
techniques; and 3) the identity and effectiveness of end-of-
pipe treatment systems. The best source of information was
the hospitals themselves. Additional information was
obtained from direct interviews and sampling visits to
production facilities.
Collection of the data necessary for development of RWL and
effluent treatment capabilities within dependable confidence
limits required analysis of treatment operations. Survey
teams composed of project engineers and scientists conducted
the actual plant visits. Information on the identity and
performance of wastewater treatment systems was obtained
through:
1. Interviews with plant water pollution control
personnel or engineering personnel.
2. Examination of treatment plant design and
historical operating data (flow rates and analyses
of influent and effluent).
3. Treatment plant influent and effluent sampling.
Information on process plant operations and the associated
RWL was obtained through:
1. Interviews with plant operating personnel.
2. Examination of plant design and operating data
(original design specification, flow sheets, day-
to-day material balances around individual process
modules or unit operations where possible).
3. Individual process wastewater sampling and
analysis.
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4. Historical operational and treatment data.
The data obtained in this manner was then utilized to
develop recommended effluent limitations, guidelines and
standards of performance for the hospital point source
category. References utilized are included in Section XV of
this report. The data obtained during the field data
collection program are included in Supplement E. Cost
information is presented in Supplement A. The documents are
available for examination by interested parties at the EPA
Public Information Reference Unit, Room 2922 (EPA Library),
Waterside Mall, 401 M St. S.W., Washington, B.C. 20460.
The following text describes the scope of the study,
technical approach to the development of effluent limitation
and the scope of coverage for data base for the hospital
point source category.
Hospitals
Scope of the Study
In order to establish boundaries on the scope of work for
this study, the hospital category was defined to include all
establishments listed under Standard Industrial
Classification (SIC) group number 806. This group includes
all establishments primarily engaged in providing diagnostic
services, extensive medical treatment, surgical services,
and other hospital services, as well as continuous nursing
services. These establishments have an organized medical
staff, in-patients, beds, and equipment and facilities to
provide complete health care.
Descriptions of the specific hospital types included
under group no. 806 are:
8062 General Medical and Surgical Hospitals
Establishments primarily engaged in providing
general medical and surgical services and other
hospital services.
8063 Psychiatric Hospitals
Establishments primarily engaged in providing
diagnostic medical services and in-patient
treatment for the mentally ill, including mental
hospitals and psychiatric hospitals.
8069 Specialty Hospitals, Except Psychiatric
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Establishments primarily engaged in providing
diagnostic services, treatment, and other hospital
services for patients with specified types of
illnesses (except mental), including:
Children's Hospitals
Chronic Disease Hospitals
Geriatric Hospitals
Eye, Ear, Nose, and
Throat Hospitals
Orthopedic Hospitals
Maternity Hospitals
Tuberculosis Hospitals
Scope of Coverage for Data Base
There are over 7,000 hospitals in the United States, of
which approximately ninety-two (92) percent send their waste
to publicly owned treatment works (POTW). The remaining
treat their own waste. These regulations are primarily
geared for this group, but the remaining ninety-two percent
will be required to meet the future pretreatment standards.
During this study, data from hospitals in Pennsylvania, New
York, New Jersey, West Virginia, California, Maine, Wyoming,
and Georgia were collected and analyzed. A total of 12
hospital facilities were studied in depth during the
project, three of which were surveyed by field sampling
teams. Data for the remaining nine hospitals were obtained
from the Veteran's Administration. These data included
extensive historical data covering years of treatment plant
operation. A substantial body of information from other
hospitals was used to confirm that a representative cross-
section was being studied. The types of hospitals studied
included general medical and surgical, psychiatric,
tuberculosis, cancer, orthopedic, and research facilities.
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SECTION IV
INDUSTRIAL CATEGORIZATION
General
The goal of this study is the development of effluent
limitations, guidelines and standards of performance and new
source performance standards for the hospital point source
category that will be achieved with different levels of in-
process waste reduction and end-of-pipe pollution control
technology. These effluent limitations, guidelines and new
source performance standards are to specify the quantity of
pollutants which will ultimately be discharged from a
specific facility and will be related to a common yardstick,
the number of occupied beds.
Hospitals
Discussion of the Rationale of Categorization
Prior to attempting development of effluent limitations,
guidelines and new source performance standards for the
hospital category, the possible need for establishing
subcategories was investigated to determine whether there
were areas of the hospital point source category category
where separate effluent limitations and standards should
apply. The following factors were considered in determining
whether subcategorization was justified.
Hospital _S_ize
From inspection of historical and survey data, it was
determined that the pounds of pollutant generated within a
hospital remains relatively constant per occupied bed. The
total volume of wastewater from different size hospitals
based on total floor space or total occupied beds did not
support relationships which would require subcategorization
into small, medium, and large hospitals.
On a unit basis, occupied beds produced a better fit for
data than unit floor area (per square foot basis). Hence,
raw waste loads were developed by counting the number of
occupied beds served and by dividing this bed utilization
figure into the amount of pollutant measured at each
hospital in the field survey. (For more detailed
information refer to Table V-2). In summary, this unit
technique proved to be a more consistent yardstick for
hospitals rather than absolute size of the hospitals.
19
-------
Therefore, categorization based on hospital size is not
justified.
Hospital Age
During the survey, both old and new hospitals were studied.
Because hospitals continually undate their equipment and
services, and based on an analysis of the survey and
historical data, it was concluded that hospital age is not a
significant factor in determining the characteristics of a
hospital's wastewater.
Hospital Location
The states surveyed during the study include Pennsylvania,
New York, West Virginia, California, New Jersey, Maine,
Wyoming, and Georgia. Analysis of data from hospitals in
these various geographical areas of the United States
indicated that location has little effect on the quality or
quantity of the wastewaters generated by a hospital
facility. Therefore, location is not a basis for
subcategorization.
Hospital Type
Hospitals specializing in different types of services were
studied during the project. These services included general
medical and surgical, psychiatric, tuberculosis, cancer,
orthopedic, and research. Because the majority of water-
borne waste generated from hospitals is excrement of human
origin, it was concluded that the type of service provided
by a hospital did not form a basis for subcategorization or
have an effect on the quality or quantity of wastewater.
Nature of Wastes Generated
Hospital wastewater samples were collected and analyzed
during the project and additional data compiled by the
Veterans Administration were also obtained. Analysis of
these data indicated that the wastewater characteristics
exhibited by the hospitals studied were fairly uniform.
Therefore, it was concluded that the nature of the
wastewaters generated by hospitals is similar, and this
factor does not form a basis for subcategorization.
Treatability of Wastewaters
Although approximately ninety-two (92) percent of hospitals
discharge their wastewaters to POTW sewer systems,
biological on-site treatment systems are employed in some
20
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cases. The predominate type of on-site treatment utilized
by hospitals is a trickling filter, although some activated
sludge and aerated lagoon systems were also observed. The
contaminant concentrations and pollutant loadings recorded
by the hospitals studied were very similar. Hospital
wastewaters are similar to municipal raw wastewaters except
for the increased loading contributed by both patients and
service personnel when raw waste load is measured on an
occupied bed basis. It was concluded that hospital waste-
waters are amenable to biological treatment and therefore
wastewater treatability characteristics did not warrant
subcategorization.
Summary of Considerations
It was concluded that the wastewater characteristics of the
hospitals studied were very similar and independent of all
of the above factors. Therefore, for the purpose of
establishing effluent limitations, guidelines and new source
performance standards for hospitals, additional
subcategorization of this category was not required.
Category Description
The three major areas in a hospital which generate
wastewaters are patient rooms and staff facilities,
laundries, and cafeterias. Sanitary flows are the primary
wastes from hospital patient rooms and, obviously, the more
beds a hospital has, the more significant this flow will be.
Cafeterias are another large contributor to the wastewaters
generated by hospitals. The cleaning of foodstuffs,
preparation of meals, washing of dishes, and floor and
equipment cleaning are all activities which generate
wastewaters from a cafeteria. These wastes usually contain
organic matter, in dissolved and colloidal states, and oils
and greases in varying degrees of concentration. The third
major contributor of wastewaters in a hospital is laundries.
Laundry wastes originate from the use of soap, soda, and
detergents. Following the washing cycle, the dirty wash
water is discharged to the sewer. Laundry wastes generally
have a high turbidity, alkalinity, and BOD content.
Three other areas in a hospital which discharge smaller
quantities of wastewaters are surgical rooms, laboratories,
and x-ray departments. Surgical room wastewaters are
primarily washwaters from cleaning activities. Laboratory
wastes generally consist of solvents, glassware washwater,
and various reagents used in the laboratory. Research
hospitals may also have animal cage washings in their
laboratory wastes. X-ray departments are an additional
21
-------
source of wastewaters. These wastes consist of spent
solutions of developer and fixer, containing thiosulfates
and compounds of silver. The solutions are usually alkaline
and contain various organic reducing agents. Most hospitals
recover the silver from spent x-ray film developing
solutions. Most pathological wastes from surgical suites
are collected and disposed of in hospital pathological
i nc inerator s.
Some hospitals generate radioactive wastes from diagnostic
and therapeutic uses. Iodine-131 and phosphorus-32 are the
radioisotopes which predominate in hospital radioactive
wastes. Fortunately, these possess short half-lives, and
simple detention tanks can render them inactive. The
handling of radioactive waste is closely monitored by NRC,
and these wastes are not discharged to the hospital sewer
system.
22
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SECTION V
WASTE CHARACTERIZATION
The primary sources of wastewater streams from hospitals
include sanitary wastewaters, discharges from surgical
rooms, laboratories, laundries, x-ray departments,
cafeterias, and glassware washing. Wastewaters from
hospitals can be characterized as containing BODS, COD, and
TSS concentrations comparable to normal domestic sewage and
readily amenable to biological treatment.
Specific contaminants which may appear in hospital
wastewater include mercury, silver, barium, beryllium and
boron. Mercury is used primarily in hospital laboratories,
but also appears in various forms in medicines,
disinfectants, and mildew inhibitors and may arise as a
result of poor handling from laundry facilities from such
sources as broken thermometers. Silver contamination comes
from spent developer solutions discarded by hospital x-ray
departments. These developers are used in processing x-ray
films. Boron is another contaminant which may appear in x-
ray department wastes. This element is found in fixer
solutions used in automatic film processing equipment.
Barium injections are used for diagnostic purposes, and this
metal may appear in a hospital's sanitary wastes. Beryllium
is used in dental laboratories. During the survey,
beryllium was not found to be present in significant
quantities in the waste loads generated from hospitals.
The characteristics of the wastewater generated by a
hospital can be affected by various pollution control
practices inside the hospital. Programs to eliminate or
reduce the discharge of mercury, solvents, and various
strong reagents have been initiated by some hospitals.
These wastes are collected in special containers and
periodically disposed of by a private contractor. Boron has
been eliminated from some hospital wastes by switching to
boron-free film developing chemicals. A common practice at
many hospitals is the recovery of silver from film
developing wastes. This can be accomplished by the use of
silver recovery equipment on site or by collecting the waste
and having a contractor periodically pick up the waste for
silver recovery.
Five major parameters were considered while analyzing
hospital wastewater characteristics:
1. BOD5 raw waste loading (expressed as Ibs BOD5/1000
23
-------
occupied beds)
2. COD raw waste loading (expressed as Ibs COD/1000
occupied beds)
3. TSS raw waste loading (expressed as Ibs TSS/1000
occupied beds)
4. TOC raw waste loading (expressed as Ibs TOC/1000
occupied beds)
5. Wastewater flow loading (expressed as gals/1000
occupied beds)
For explanation of parameters, refer to Section VI. The raw
waste load (RWL) figures computed for the hospitals studied
are presented in Table V-1. The RWL values for hospitals
were developed by averaging the RWL values computed for
individual hospitals. These RWL values are also shown in
Table V-1. The RWL for all other parameters (except BOD5r
COD, TSS, and TOC) computed from the field survey data and
the historical data are presented in Table V-2.
The RWL data are plotted as pollutant RWL versus wastewater
flow loading in Figure V-1. This type of plot is a
convenient device for illustrating the quality or strength
of the wastewaters generated by hospitals. Since both the
loading (ordinate) and flow (abscissa) are expressed on a
1,000-bed basis, dividing the loading by the flow gives a
slope which is representative of waste concentration. For
orientation, reference lines of constant concentration have
been drawn diagonally across each of the plots. Relating a
specific data point to one of these lines provides a
convenient estimate of raw waste concentrations. This plot
indicates that no definite relationships appear to exist
between pollutant RWL and flow RWL. However, the strength
of the pollutant waste load remains fairly constant (as a
function of a 1000 bed occupancy) even though the base
fluctuates. Pollutant data points generally fall into the
following concentation ranges:
BCD5 - 100 to 400 mg/1
COD - 300 to 800 mg/1
TSS - 60 to 200 mg/1
TOC - 100 to 300 mg/1
These narrow ranges of concentration indicate that the
characteristics of the hospital wastes surveyed were fairly
uniform.
The average quantity of wastewater generated per total
number of beds was 319 gpd/occupied bed. This compares
favorably with the value of 242 gpd/occupied bed reported by
the American Hospital Association.
24
-------
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25
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Table V -2
2/13/76
Raw Waste Loads
Number of Occupied Beds
Flow - liters/1,000 beds1
(gallons/1,000 beds1)
Raw Waste Loads
IDS - kg/1,000 beds1
(lbs/1,000 beds1)
TKN
NO^-Ni trogen
Total Phosphorus
Oil & Grease
Cyanide
Phenol
1 ron
Lead
Mercury
Copper
Chromium (Total)
Arsenic
Bar!urn
"Silver
Boron
Manganese
Sulfate
Hospi tal
No. 91
268
2,090,000
(552,000)
1,1(80
(3,260)
55.8
(123)
0.0
(0.0)
16.1
(35.5)
67-6
(149)
0.0
(0.0)
3.63
(8.00)
2.97
(6.55)
0.0
(0.0)
0.018
(o.o4o)
0.29
(0.6*1)
0.17
(0.37)
0.0
(0.0)
7.62
(16.8)
0.59
(1.3D
0.98
(2.17)
(-)
(-)
Hospital
No. 92
183
954,000
(252,000)
790
(1,740)
24.7
(54.5)
0.37
(0.82)
21.1
(46.6)
73.5
(162)
0.0
(0.0)
0.12
(0.26)
2.49
(5.48)
0.0
(o.o)
0.0018
(0.004)
0.60
(1-33)
0.0
(o.o)
(-)
0.0
(o.o)
0.22
(0.48)
0.48
(1.07)
.07
(.16)
(-)
Hospital
No. 93
835
1,310,000
(347,000)
540
(1,190)
60.4
(133)
1.45
(3.2)
6.86
(15-1)
(-)
0.0
(o.o)
(-)
(-)
(-)
(-)
(-)
(-)
(-)
(-)
0.41
(0.90)
0.91
(2.0)
(-)
52.2
(115)
Average
m.
937
(2,060)
47.0
(103)
0.61
(1.34)
14.7
(32.3)
70.6
(155)
0.0
(o.o)
1.88
(4.13)
2.73
(6.01)
0.0
(o.o)
0.01
(0.022)
0.44
(0.98)
0.085
(0.19)
0.0
(0.0)
3.81
(8.39)
0.41
(0.90)
0.79
(1.74)
.07
(.16)
52.2
(115)
Occupied Beds
26
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27
-------
The correlation between BODS and COD, BODS and TOG, and BODS
and TSS raw waste loads were checked to see if any apparent
relationships existed. A close correlation was observed
between BOD5 and COD, and between BOC5 and TOC RWLs. The
BODJ5/COD and BOE5/TOC ratios ranged between .37 and .42, and
1.3 and 1.5 respectively. The correlation between BCD5 and
TSS RWL's were not as close. The BOD5/TSS ratios observed
varied from 1.0 to 2.4. See Figure V-1.
28
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SECTION VI
SELECTION OF POLLUTANT PARAMETERS
General
From review of NPDES permit applications for direct
discharge of wastewaters from various hospitals and
examination of related published data, parameters (listed in
Table VI-1) were selected and examined for all industrial
wastewaters during the field data collection program. In
addition, several specific parameters were examined. All
field sampling data are summarized in Supplement B.
Supplement B includes laboratory analytical results, data
from plants visited, RWL calculations, historical data,
analysis of historical data, computer print-outs (showing
flows, production, and pollutants, performance data on
treatment technologies and effluent limitations
calculations). Supplement A has design calculations,
capital cost calculations, and annual cost calculations.
Supplements A and B are available at the EPA Public
Information Reference Unit, Room 2922 (EPA Library),
Waterside Mall, Washington, D.C. 20160.
The degree of impact on the overall environment has been
used as a basis for dividing the pollutants into groups as
follows:
1. Pollutants of significance.
2. Pollutants of limited significance.
3. Pollutants of specific significance.
The rationale and justification for pollutant categorization
within the foregoing groupings, as discussed herein, will
indicate the basis for selection of the parameters upon
which the actual effluent limitations guidelines were
postulated. In addition, particular parameters have been
discussed in terms of their validity as measures of
environmental impact and as sources of analytical insight.
Pollutants observed from the field data that were present in
sufficient concentrations so as to interfere with, be
incompatible with, or pass with inadequate treatment through
publicly owned treatment works are discussed in Section XII
of this document.
29
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Pollutants of Significance
Parameters of pollution significance for the hospital point
source category are BOD5, COD, TCC, and TSS.
BOD5, COD, and TOC have been selected as pollutants of
significance because they are the primary measurements of
organic pollution. In the survey of the industrial
categories, almost all of the effluent data collected from
wastewater treatment facilities were based upon BODS,
because almost all the treatment facilities were biological
processes. If ether processes (such as evaporation,
incineration, or activated carbon) are utilized, either COD
or TOC may be a more appropriate measure of pollution.
30
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Table VI-1
List of Parameters to be Examined
Biochemical Oxygen Demand
Chemical Oxygen Demand
Total Organic Carbon
Total Suspended Solids
Ammonia
Dissolved Solids
Barium
Beryllium
Mercury
Silver
Oil and Grease
Acidity, Alkalinity - pH
Radioactivity
Fecal Coliform
31
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Oxygen Demand (BOD, COD, TOC and DO
Organic and some inorganic compounds can cause an oxygen
demand to be exerted in a receiving body of water.
Indigenous microorganisms utilize the organic wastes as an
energy source and oxidize the organic matter. In doing so
their natural respiratory activity will utilize the
dissolved oxygen.
Dissolved oxygen (DO) in water is a quality that, in
appropriate concentrations, is essential not only to keep
organisms living but also to sustain species reproduction,
vigor, and the development of populations. Organisms
undergo stress at reduced DO concentrations that make them
less competitive and less able to sustain their species
within the aquatic environment. For example, reduced DO
concentrations have been shown to interfere with fish
population through delayed hatching of eggs, reduced size
and vigor of embryos, production of deformities in young,
interference with food digestion, acceleration of blood
clotting, decreased tolerance to certain toxicants, reduced
food utilization efficiency, growth rate, and maximum
sustained swimming speed. Other organisms are likewise
affected adversely in conditions with decreased DO. Since
all aerobic aquatic organisms need a certain amount of
oxygen, the consequences of total depletion of dissolved
oxygen due to a high oxygen demand can kill all the
inhabitants of the affected aquatic area.
It has been shown that fish may, under some natural
conditions, become acclimatized to low oxygen
concentrations. Within certain limits, fish can adjust
their rate of respiration to compensate for changes in the
concentration of dissolved oxygen. It is generally agreed,
moreover, that those species which are sluggish in movement
(e.g.,carp, pike, eel) can withstand lower oxygen
concentrations than fish (such as trout or salmon) which are
more lively in habit.
The lethal affect of low concentrations of dissolved oxygen
in water appears to be increased by the presence of toxic
substances, such as ammonia, cyanides, zinc, lead, copper,
or cresols. With so many factors influencing the effect of
oxygen deficiency, it is difficult to estimate the minimum
safe concentrations at which fish will be unharmed under
natural conditions. Many investigations seem to indicate
that a DO level of 5.0 mg/1 is desirable for a good aquatic
environment and higher DO levels are required for selected
types of aquatic environments.
32
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Biochemical oxygen demand (BOEl is the quantity of oxygen
required for the biological and chemical oxidation of
waterborn substances under ambient or test conditions.
Materials which may contribute to the BOD include:
carbonaceous organic materials usable as a food source by
aerobic organisms; oxidizable nitrogen derived from
nitrites, ammonia and organic nitrogen compounds which serve
as food for specific bacteria; and certain chemically
oxidizable materials such as ferrous iron, sulfides,
sulfite, etc. which will react with dissolved oxygen or are
metabolized by bacteria. In most industrial and municipal
waste waters, the BOD derives principally from organic
materials and from ammonia (which is itself derived from
animal or vegetable matter).
The BOD of a waste exerts an adverse effect upon the
dissolved oxygen resources of a body of water by reducing
the oxygen available to fish, plant life, and other aquatic
species. Conditions can be reached where all of the
dissolved oxygen in the water is utilized resulting in
anaerobic conditions and the production of undesirable gases
such as hydrogen sulfide and methane. The reduction of
dissolved oxygen can be detrimental to fish populations,
fish growth rate, and organisms used as fish food. A total
lack of oxygen due to the exertion of an excessive BOD can
result in the death of all aerobic aquatic inhabitants in
the affected area.
Water with a high BOD indicates the presence of decomposing
organic matter and associated increased bacterial
concentrations that degrade its quality and potential uses.
A by-product of high BOD concentrations can be increased
algal concentrations and blooms which result from
decomposition of the organic matter and which form the basis
of algal populations.
The BODJ3 (5-day BOD) test is used widely to estimate the
pollutional strength of domestic and industrial wastes in
terms of the oxygen that they will require if discharged
into receiving streams. The test is an important one in
water pollution control activities. It is used for
pollution control regulatory activities, to evaluate the
design and efficiencies of waste water treatment works, and
to indicate the state of purification or pollution of
receiving bodies of water.
Complete biochemical oxidation of a given waste may require
a period of incubation too long for practical analytical
test purposes. For this reason, the 5-day period has been
accepted as standard, and the test results have been
33
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designated as BOD5. Specific chemical test methods are not
readily available for measuring the quantity of many
degradable substances and their reaction products. Reliance
in such cases is placed on the collective parameter, BOD5,
which measures the weight of dissolved oxygen utilized by
microorganisms as they oxidize or transform the gross
mixture of chemical compounds in the waste water. The
biochemical reactions involved in the oxidation of carbon
compounds are related to the period of incubation. The
five-day BOD normally measures only 60 to 80% of the
carbonaceous biochemical oxygen demand of the sample, and
for many purposes this is a reasonable parameter.
Additionally, it can be used to estimate the gross quantity
of oxidizable organic matter.
The BOD5 test is essentially a bioassay procedure which
provides an estimate of the oxygen consumed by
microorganisms utilizing the degradable matter present in a
waste under conditions that are representative of those that
are likely to occur in nature. Standard conditions of time,
temperature, suggested microbial seed, and dilution water
for the wastes have been defined and are incorporated in the
standard analytical procedure. Through the use of this
procedure, the oxygen demand of diverse wastes can be
compared and evaluated for pollution potential and to some
extent for treatability by biological treatment processes.
Because the BOD test is a bioassay procedure, it is
important that the environmental conditions of the test be
suitable for the microorganisms to function in an
uninhibited manner at all times. This means that toxic
substances must be absent and that the necessary nutrients,
such as nitrogen, phosphorous, and trace elements, must be
present.
Chemical Oxygen Demand (COD) is a purely chemical oxidation
test devised as an alternate method of estimating the total
oxygen demand of a waste water. Since the method relies on
the oxidation-reduction system of chemical analyses rather
than on biological factors it is more precise, accurate, and
rapid than the BOD test. The COD test is widely used to
estimate the total oxygen demand (ultimate rather than 5-day
BOD) to oxidize the compounds in a waste water. It is based
on the fact that organic compounds, with a few exceptions,
can be oxidized by strong chemical oxidizing agents under
acid conditions with the assistance of certain inorganic
catalysts.
The COD test measures the oxygen demand of compounds that
are biologically degradable and of many that are not.
34
-------
Pollutants which are measured by the BOD5 test will be
measured by the COD test. In addition, pollutants which are
more resistant to biological oxidation will also be measured
by COD. COD is a more inclusive measure of oxygen demand
than is BOD5 and will result in higher oxygen demand values
than will the BODjj test.
The compounds which are more resistant to biological
oxidation are becoming of greater and greater concern not
only because of their slow but continuing oxygen demand on
the resources of the receiving water, but also because of
their potential health effects on aquatic life and humans.
Many of these compounds result from industrial discharges
and some have been found to have carcinogenic, mutagenic and
similar adverse effects, either singly or in combination.
Concern about these compounds has increased as a result of
demonstrations that their long life in receiving waters -
the result of a slow biochemical oxidation rate - allows
them to contaminate downstream water intakes. The commonly
used systems of water purification are not effective in
removing these types of materials and disinfection such as
chlorination may convert them into even more hazardous
materials.
Thus the COD test measures organic matter which exerts an
oxygen demand and which may affect the health of the people.
It is a useful analytical tool for pollution control
activities. It provides a more rapid measurement of the
oxygen demand and an estimate of organic compounds which are
not measured in the BOD_5 test.
Total organic carbon (TOC) is measured by the catalytic
conversion cf organic carbon in a waste water to carbon
dioxide. Most organic chemicals have been found to be
measured quantitatively by the equipment now in use. The
time of analyses is short, from 5 to 10 minutes, permitting
a rapid and accurate estimate of the organic carbon content
of the waste waters to be made by relatively unskilled
personnel.
A TOC value does not indicate the rate at which the carbon
compounds are oxidized in the natural environment. The TOC
test will measure compounds that are readily biodegradable
and measured by the BODji test as well as those that are not.
TOC analyses will include those biologically resistant
organic compounds that are of concern in the environment.
BOD and COD methods of analyses are based on oxygen
utilization of the waste water. The TOC analyses estimates
the total carbon content of a waste water. There is as yet
35
-------
no fundamental correlation of TOC to either BOD or COD.
However, where organic laden waste waters are fairly
uniform, there will be a fairly constant correlation among
TOC, BOD and COD. Once such a correlation is established,
TOC can be used as an inexpensive test for routine process
monitoring.
Total Suspended Solids (TSS)
Suspended solids include both organic and inorganic
materials. The inorganic compounds include sand, silt, and
clay. The organic fraction includes such materials as
grease, oil, tar, and animal and vegetable waste products.
These solids may settle out rapidly and bottom deposits are
often a mixture of both organic and inorganic solids.
Solids may be suspended in water for a time, and then settle
to the bed of the stream or lake. These solids discharged
with man's wastes may be inert, slowly biodegradable
materials, or rapidly decomposable substances. While in
suspension, they increase the turbidity of the water, reduce
light penetration and impair the photosynthetic activity of
aquatic plants.
Suspended solids in water interfere with many industrial
processes, cause foaming in boilers and incrustations on
equipment exposed to such water, especially as the
temperature rises. They are undesirable in process water
used in the manufacture of steel, in the textile industry,
in laundries, in dyeing and in cooling systems.
Solids in suspension are aesthetically displeasing. When
they settle to form sludge deposits on the stream or lake
bed, they are often damaging to the life in water. Solids,
when transformed to sludge deposits, may do a variety of
damaging things, including blanketing the stream or lake bed
and thereby destroying the living spaces for those benthic
organisms that would otherwise occupy the habitat. When of
an organic nature, solids use a portion or all of the
dissolved oxygen available in the area. Organic materials
also serve as a food source for sludgeworms and associated
organisms.
Disregarding any toxic effect attributable to substances
leached out by water, suspended solids may kill fish and
shellfish by causing abrasive injuries and by clogging the
gills and respiratory passages of various aquatic fauna.
Indirectly, suspended solids are inimical to aquatic life
because they screen out light, and they promote and maintain
the development of noxious conditions through oxygen
depletion. This results in the killing of fish and fish
36
-------
food organisms. Suspended solids also reduce the
recreational value of the water.
Turbidity: Turbidity of water is related to the amount of
suspended and colloidal matter contained in the water. It
affects the clearness and penetration of light. The degree
of turbidity is only an expression of one effect of
suspended solids upon the character of the water. Turbidity
can reduce the effectiveness of chlorination and can result
in difficulties in meeting BOD and suspended solids
limitations. Turbidity is an indirect measure of suspended
solids.
Pollutants of Limited Significance
The following parameters, which were investigated in
particular cases, have significant effects on the
applicability of end-of-pipe treatment technologies.
Ammonia (NH3)
Ammonia occurs in surface and ground waters as a result of
the decomposition of nitrogenous organic matter. It is one
of the constituents of the complex nitrogen cycle. It may
also result from the discharge of industrial wastes from
chemical or gas plants, from refrigeration plants, from
scouring and cleaning operations where "ammonia water" is
used from the processing of meat and poultry products, from
rendering operations, from leather tanning plants, and from
the manufacture of certain organic and inorganic chemicals.
Because ammonia may be indicative of pollution and because
it increases the chlorine demand, it is recommended that
ammonia nitrogen in public water supply sources not exceed
0.5 mg/1.
Ammonia exists in its non-ionized form only at higher pH
levels and is most toxic in this state. The lower the pH,
the more ionized ammonia is formed, and its toxicity
decreases. Ammonia, in the presence of dissolved oxygen, is
converted to nitrate (NO3) by nitrifying bacteria. Nitrite
(NO2), which is an intermediate product between ammonia and
nitrate, sometimes occurs in quantity when depressed oxygen
conditions permit. Ammonia can exist in several other
chemical combinations including ammonium chloride and other
salts.
Nitrates are considered to be among the objectionable
components of mineralized waters. Excess nitrates cause
irritation to the gastrointestinal tract, causing diarrhea
and diuresis. Methemoglobinemia, a condition characterized
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by cyanosis and which can result in infant and animal
deaths, can be caused by high nitrate concentrations in
waters used for feeding. Ammonia can exist in several other
chemical combinations, including ammonium chloride and other
salts. Evidence exists that ammonia exerts a toxic effect
on all aquatic life depending upon the pHr dissolved oxygen
level, and the total ammonia concentration in the water. A
significant oxygen demand can result from the microbial
oxidation of ammonia. Approximately 4.5 grams of oxygen are
required for every gram of ammonia that is oxidized.
Ammonia can add to eutrophication problems by supplying
nitrogen to aquatic life. Ammonia can be toxic, exerts an
oxygen demand, and contributes to eutrophication.
Dissolved Solids
In natural waters, the dissolved solids are mainly
carbonates, chlorides, sulfates, phosphates, and, to a
lesser extent, nitrates of calcium, magnesium, sodium, and
potassium, with traces of iron, manganese and other
substances. The summation of all individual dissolved solid
is commonly referred to as total dissolved solids.
Many communities in the United States and in other countries
use water supplies containing 2,000 to 4,000 mg/1 of
dissolved salts, when no better water is available. Such
waters are not palatable, may not quench thirst, and may
have a laxative action on new users. Waters containing more
than 4,000 mg/1 of total salts are generally considered
unfit for human use, although in hot climates such higher
salt concentrations can be tolerated. Waters containing
5,000 mg/1 or more are reported to be bitter and act as a
bladder and intestinal irritant. It is generally agreed
that the salt concentration of good, palatable water should
not exceed 500 mg/1.
Limiting concentrations of dissolved solids for fresh-water
fish may range from 5,000 to 10,000 mg/1, depending on
species and prior acclimatization. Some fish are adapted to
living in more saline waters, and a few species of fresh-
water forms have been found in natural waters with a salt
concentration of 15,000 to 20,000 mg/1. Fish can slowly
become acclimatized to higher salinities, but fish in waters
of low salinity cannot survive sudden exposure to high
salinities, such as those resulting from discharges of oil-
well brines. Dissolved solids may influence the toxicity of
heavy metals and organic compounds to fish and other aquatic
life, primarily because of the antagonistic effect of
hardness on metals.
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Waters with total dissolved solids (TDS) concentrations
higher than 500 mg/1 have decreasing utility as irrigation
water. At 5,000 mg/1, water has little or no value for
irrigation.
Dissolved solids in industrial waters can cause foaming in
boilers and can cause interference with cleanliness, color,
or taste of many finished products. High concentrations of
dissolved solids also tend to accelerate corrosion.
Specific conductance is a measure of the capacity of water
to convey an electric current. This property is related to
the total concentration of ionized substances in water and
to the water temperature. This property is frequently used
as a substitute method of quickly estimating the dissolved
solids concentration.
Barium (B_a)
Barium is an alkaline earth metal rapidly decomposed by
water to form barium ions. Many of its salts are soluble,
but the carbonate and sulfate are highly insoluble.
Consequently, it is expected that any barium ions discharged
to natural waters are precipitated and removed by adsorption
or sedimentation. Barium and its salts have many uses in
the metallurgical industry (for special alloys), in the
paint industry, in the ceramic and glass industries, and in
the medical technology industry (for x-ray diagnosis).
Barium has no proven accumulative effects on humans and is
eliminated more rapidly than calcium. However, a mandatory
limit of 1 mg/liter has been issued for the amount of barium
in domestic water supplies due to possible toxic effects of
barium on the heart, blood vessels and nerves. A fatal dose
is somewhere in the order of 550 to 600 mg. Barium is a
pollutant parameter in certain industries and limitations
may be necessary only on the discharges from those
industries.
Beryllium (Be)
Beryllium is found in some 30 mineral species, the most
important commercial source being beryl. A relatively rare
element, it is not likely to occur in natural waters.
Although the chloride and nitrate forms are very soluble in
water and the sulfate moderately so, the carbonate and
hydroxide are almost insoluble in cold water.
Beryllium is employed as an alloying agent in producing
beryllium copper which is used extensively for springs.
39
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electrical contacts, spot welding electrodes, and non-
sparking tools. It is also used to produce special alloys
in the manufacture of x-ray diffraction tubes and electrodes
for neon signs. It is finding application as a structural
material for high speed aircraft, missiles, and spacecraft
and is now used in nuclear reactors as a reflector or
moderator. It also finds use in gyroscopes, computer parts,
and inertia1 guidance systems.
Beryllium and its compounds, when present in the
environment, are of concern because of their effect on the
health of humans and animals since beryllium is among the
most toxic and hazardous of the nonradioactive substances
being used in industry. Almost all the presently known
beryllium compounds are acknowledged to be toxic in both the
soluble and insoluble forms. The toxicity of beryllium is
much less in water than in the atmosphere since absorption
of beryllium from the alimentary tract is slight (about
0.006 percent of that ingested), and excretion is fairly
rapid. Beryllium is considerably more toxic in soft water
than in hard water. At acid pH values, beryllium is highly
toxic to plants.
Concentrations of beryllium sulfate complexed with sodium
tartrate up to 28.5 mg/1 are not toxic to goldfish, minnows,
or snails. The 96-hour minimum toxic level of beryllium
sulfate for fathead minnows has been found to be 0.2 mg/1 in
soft water and 11 mg/1 in hard water. The corresponding
level for beryllium chloride is 0.15 mg/1 in soft water and
15 mg/1 in hard water.
Although toxic, beryllium normally is not selected as a
pollutant parameter requiring an effluent limitation since
it is found in relatively low concentrations or is non-
existent in the raw waste streams of most industries.
Mercury (Hg)
Mercury is an elemental metal that is rarely found in nature
as a free metal. The most distinguishing feature is that it
is a liquid at ambient conditions. Mercury is relatively
inert chemically and is insoluble in water. Its salts occur
in nature chiefly as the sulfide (HgS) known as cinebar.
Mercury is used extensively in measuring instruments and in
mercury batteries. It is also used in electroplating, in
chemical manufacturing and in some pigments for paints. The
electrical equipment industry uses mercury in the
manufacture of lamp switches and ether devices.
40
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Mercury can be introduced into the body through the skin and
the respiratory system. Mercuric salts are highly toxic to
humans and can be readily absorbed through the
gastrointestinal tract. Fatal doses can vary from 3 to 30
grams. The total mercury in public water supply sources has
been recommended not to exceed 0.002 mg/1.
Mercuric salts are extremely toxic to fish and other aquatic
life. Mercuric chloride is more lethal than copper,
hexavalent chromium, zinc, nickel, and lead towards fish and
aquatic life. In the food cycle, algae containing mercury
up to 100 times the concentration of the surrounding sea
water are eaten by fish which further concentrate the
mercury and predators that eat the fish in turn concentrate
the mercury even further.
Silver (As)
Silver is a soft lustrous white metal that is insoluble in
water and alkali. It is readily ionized by electrolysis and
has a particular affinity for sulfur and halogen elements.
In nature, silver is found in the elemental state and
combined in ores such as argentite (Ag2S), horn silver
(AgCl) , proustite (Ag_3A S3_) , and pyrargyrite (Ag3SbSj) .
From these ores, silver ions may be leached into ground
waters and surface waters, but since many silver salts such
as the chloride, sulfide, phosphate, and arsenate are
insoluble, silver ions do not usually occur in significant
concentration in natural waters.
Silver is used extensively in electroplating, photographic
processing, electrical equipment manufacture, soldering and
brazing and battery manufacture. Of these, the two major
sources of soluble silver wastes are the photographic and
electroplating industries with about 30% of U. S. industrial
consumption of silver going into the photographic industry.
Silver is also used in its basic metal state for such items
as jewelry and electrical contacts.
While metallic silver itself is not considered to be
poisonous for humans, most of its salts are poisonous due to
anions present. Silver compounds can be absorbed in the
circulatory system and reduced silver deposited in the
various tissues of the body. A condition known as argyria,
a permanent greyish pigmentation of the skin and mucous
membranes, can result. Concentrations in the range of 0.4-1
mg/liter have caused pathologic changes in the kidneys,
liver and spleen of rats.
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Silver is recognized as a bactericide and doses as low as
0.000001 to 0.5 mg/1 have been reported as sufficient to
sterilize water.
Oil and Grease
Because of widespread use, oil and grease occur often in
waste water streams. These oily wastes may be classified as
follows:
1. Light Hydrocarbons - These include light fuels such
as gasoline, kerosene, and jet fuel, and
miscellaneous solvents used for industrial
processing, degreasing, or cleaning purposes. The
presence of these light hydrocarbons may make the
removal of other heavier oily wastes more
difficult.
2. Heavy Hydrocarbons, Fuels, and Tars - These include
the crude oils, diesel oilsr #6 fuel oil, residual
oils, slop oils, and in some cases, asphalt and
road tar.
3. Lubricants and Cutting Fluids - These generally
fall into two classes: non-emulsifiable oils such
as lubricating oils and greases and emulsifiable
oils such as water soluble oils, rolling oils,
cutting oils, and drawing compounds. Emulsifiable
oils may contain fat soap or various other
additives.
4. Vegetable and animal fats and Oils - These
originate primarily from processing of foods and
natural products.
These compounds can settle or float and may exist as
solids or liquids depending upon factors such as method
of use, production process, and temperature of waste
water.
Oils and grease even in small quantities cause troublesome
taste and odor problems. Scum lines from these agents are
produced on water treatment basin walls and other
containers. Fish and water fowl are adversely affected by
oils in their habitat. Oil emulsions may adhere to the
gills of fish causing suffocation, and the flesh of fish is
tainted when they eat microorganisms that were exposed to
waste oil. Deposition of oil in the bottom sediments of
water can serve to inhibit normal benthic growth. Oil and
grease exhibit an oxygen demand.
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Levels of oil and grease which are toxic to aquatic
organisms vary greatly, depending on the type and the
species susceptibility. However, it has been reported that
crude oil in concentrations as low as 0.3 mg/1 is extremely
toxic to fresh-water fish. It has been recommended that
public water supply sources be essentially free from oil and
grease.
Oil and grease in quantities of 100 1/sq km show up as a
sheen on the surface of a body of water. The presence of
oil slicks prevent the full aesthetic enjoyment of water.
The presence of oil in water can also increase the toxicity
of other substances being discharged into the receiving
bodies of water. Municipalities frequently limit the
quantity of oil and grease that can be discharged to their
waste water treatment systems by industry.
Acidity and Alkalinity - pH
Although not a specific pollutant, pH is related to the
acidity or alkalinity of a waste water stream. It is not a
linear or direct measure of either, however, it may properly
be used as a surrogate to control both excess acidity and
excess alkalinity in water. The term pH is used to describe
the hydrogen ion - hydroxyl ion balance in water.
Technically, pH is the hydrogen ion concentration or
activity present in a given solution. pH numbers are the
negative logarithim of the hydrogen ion concentration. A pH
of 7 generally indicates neutrality or a balance between
free hydrogen and free hydroxyl ions. Solutions with a pH
above 7 indicate that the solution is alkaline, while a pH
below 7 indicate that the solution is acid.
Knowledge of the pH of water or waste water is useful in
determining necessary measures for corrosion control,
pollution control, and disinfection. Waters with a pH below
6.0 are corrosive to water works structures, distribution
lines, and household plumbing fixtures and such corrosion
can add constituents to drinking water such as iron,
copper, zinc, cadmium, and lead. Low pH waters not only
tend to dissolve metals from structures and fixtures but
also tend to redissolve or leach metals from sludges and
bottom sediments. The hydrogen ion concentration can affect
the "taste" of the water and at a low pH, water tastes
11 sour".
Extremes of pH or rapid pH changes can exert stress
conditions or kill aquatic life outright. Even moderate
changes from "acceptable" criteria limits of pH are
deleterious to some species. The relative toxicity to
43
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aquatic life of many materials is increased by changes in
the water pH. For example, metalocyanide complexes can
increase a thousand-fold in toxicity with a drop of 1.5 pH
units. Similarly, the toxicity of ammonia is a function of
pH. The bactericidal effect of chlorine in most cases is
less as the pH increases, and it is economically
advantageous to keep the pH close to 7.
Acidity is defined as the quantative ability of a water to
neutralize hydroxyl ions. It is usually expressed as the
calcium carbonate equivalent of the hydroxyl ions
neutralized. Acidity should not be confused with pH value.
Acidity is the quantity of hydrogen ions which may be
released to react with or neutralize hydroxyl ions while pH
is a measure of the free hydrogen ions in a solution at the
instant the pH measurement is made. A property of many
chemicals, called buffing, may hold hydrogen ions in a
solution from being in the free state and being measured as
pH. The bond of most buffers is rather weak and hydrogen
ions tend to be released from the buffer as needed to
maintain a fixed pH value.
Highly acid waters are corrosive to metals, concrete and
living organisms, exhibiting the pollutional characteristics
outlined above for low pH waters. Depending on buffering
capacity, water may have a higher total acidity at pH values
of 6.0 than other waters with a pH value of U.O.
Alkalinity; Alkalinity is defined as the ability of a water
to neutralize hydrogen ions. It is usually expressed as the
calcium carbonate equivalent of the hydrogen ions
neutralized.
Alkalinity is commonly caused by the presence of carbonates,
bicarbonates, hydroxides and to a lesser extent by borates,
silicates, phophates and organic substances. Because of the
nature of the chemicals causing alkalinity, and the buffing
capacity of carbon dioxide in water, very high pH values are
seldom found in natural waters.
Excess alkalinity as exhibited in a high pH value may make
water corrosive to certain metals, to most natural organic
materials and toxic to living organisms.
Ammonia is more lethal with a higher pH. The lacrimal fluid
of the human eye has a pH of approximately 7.0 and a
deviation of 0.1 pH unit from the norm may result in eye
irritation for the swimmer. Appreciable irritation will
cause severe pain.
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Radioactivity
Ionizing radiation is recognized as injurious when absorbed
in living tissue in quantities substantially above that of
natural background levels. It is necessary, therefore, to
prevent any living organism - humans, fishes, and
invertebrates - from being exposed to excessive radiation.
Beyond the fact that radioactive wastes emit ionizing
radiation, they are also similar in many respects to other
chemical wastes. Man's senses cannot detect radiation until
it is present in massive amounts.
To be a significant factor in the cycling of radionuclides
in the aquatic environments, plants and animals must
accumulate the radionuclide, retain it, be eaten by another
organism, and be digested. However, even if an organism
with radionuclide is not eaten before it dies, its
radionuclide can enter the "biological cycle" through
organisms decomposing the dead organism into elemental
components. Plants and animals which become radioactive in
this way do, thus, pose a health hazard when eaten by man.
Aquatic life may receive radiation from radionuclides
present in the water substrate, and also from radionuclides
that may accumulate in their tissues. Humans can acquire
radionuclides in many ways. Among the most important are by
drinking contaminated water and eating fish and shellfish
containing concentrated nuclides. When fish or other
aquatic products which have accumulated radioactive
materials are used as food by humans, the concentrations of
the nuclides in the water must be further restricted, in
order to provide assurance that the total intake of
radionuclides from all sources will not exceed the
recommended levels.
In order to prevent dangerous radiation exposure to humans,
fish, and other important organisms, the concentrations of
radionuclides in water, both fresh and marine, must be
restricted.
Fecal Coliform
Fecal coliforms are used as an indicator since they have
originated from the intestinal tract of warm-blooded
animals. Their presence in water indicates the potential
presence of pathogenic bacteria and viruses.
The presence of coliforms, more specifically fecal
coliforms, in water is indicative of fecal pollution. In
general, the presence of fecal coliform organisms indicates
45
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recent and possibly dangerous fecal contamination. When the
fecal coliform count exceeds 2,000 per 100 ml there is a
high correlation with increased numbers of both pathogenic
viruses and bacteria.
Many microorganisms, pathogenic to humans and animals, may
be carried in surface water, particularly that derived from
effluent sources which find their way into surface water
from municipal and industrial wastes. The diseases
associated with bacteria include bacillary and amoebic
dysentery. Salmonella gastroenteritis, typhoid and
paratyphoid fevers, leptospirosis, cholera, vitriosis, and
infectious hepatitis. Recent studies have emphasized the
value of fecal coliform density in assessing the occurrence
of Salmonella, a common bacterial pathogen in surface water.
Field studies involving irrigation water, field crops, and
soils indicate that when the fecal coliform density in
stream waters exceeded 1,000 per 100 ml, the probability of
occurrence of Salmonella was 53.5 percent.
Pollutants of specific Significance
The pollutant raw waste loads computed for the hospitals
category are presented in Tables V-1 and V-2.
Pollutants of special concern in the hospital category are
silver and mercury; these compounds in large enough
concentrations will have significant effects on the
applicability of end-of-pipe treatment technologies. Other
pollutants of concern are barium and toron.
The possibility of discharge of significant quantities of
these four materials from hospitals exists. However, the
hospitals visited during the sampling period discharged very
small quantities of these materials. Through proper
handling, reduction of use, and proper disposal and recovery
techniques, the discharge of these materials to the
wastewater stream can be greatly reduced.
Silver
Silver discharge is associated with the development of x-
rays. If the silver level is above the minimum, the silver
recovery system should be carefully reviewed. The most
efficient method is to collect all effluent from the
processors and physically remove the liquid from the
hospital. Several service companies are equipped to do
this.
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There are also in-line recovery units that basically work on
the principle of an electroplating system. Disposal of
scrap x-ray film is also closely related to the scrap silver
recovery. A definite economic advantage can also be
realized in hospitals developing large quantities of x-rays.
Mercury
Hospitals utilize mercury in its elemental form in
manometers, thermometers, and some electronic switches; the
laboratories are the biggest users of these items in
hospitals.
Mercurous and mercuric compounds are used for medicinal
purposes in diuretics, cathartics, and antiseptics;
disinfectants for cleaning; amalgams for dental procedures;
and in tissue fixatives in laboratories. Some mildew
inhibitors containing mercury are used by laundries.
Barium
Many hospitals have been following a procedure of draining
the barium with a catheter into a plastic bag, which almost
eliminates the barium from the hospital's sewage. However,
the possibility exists for accidental discharge of barium
into the waste stream.
Boron
Boron can be discharged into the sewer system via the
automatic processors in the x-ray department. The fixer has
been found to yield the greatest quantity of boron, but the
developer also contains significant quantities. In order to
minimize the boron discharged into the sewer system, boron-
free fixers and developers have been introduced by
reformulation of the chemistry to eliminate boron.
Radionuclides
The fate of radionuclides released to the environment by
medical activities can be of concern. Possible
radioisotopes in hospital wastewaters include iodine-131,
mercury-203, thorium-232, cesium-137, bismuth-214,
ruthenium-103, ruthenium-106, potassium-40, technetium-99r
and phosphorus-32. Phosphorus-32 has a half-life of 14.28
days and iodine-131 has a half-life of 8.05 days. Iodine-
131 activities ranged to 670 pCi/kg of wet sludge according
to a recent (1973) survey of ten sewage treatment plants in
a nine-city survey. Due to time and budgetary constraints
on the project, these wastes were not determined for the
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hospital point source category. It is recommended,
therefore, that where radioactive material is used the waste
be held until it is safe to release to the environment.
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SECTION VII
CONTROL AND TREATMENT TECHNOLOGIES
General
The entire spectrum of wastewater control and treatment
technology is at the disposal of the hospital point source
category. The selection of technology options depends on
the economics of that technology and the magnitude of the
final effluent concentration. Control and treatment
technology may be divided into two major groupings: in-
plant pollution abatement and end-of-pipe treatment.
After discussing the available performance data for this
point source category, conclusions will be made relative to
the reduction of various pollutants commensurate with the
following distinct technology levels:
I. Best Practicable control Technology Currently
Available (BPT)
II. Best Available Technology Economically
Achievable (BAT)
III. Best Available Demonstrated control Technology
(NSPS)
To assess the economic impact of these proposed effluent
limitations and guidelines, model treatment systems have
been proposed which are considered capable of attaining the
recommended RWL reduction. It should be noted and
understood that the particular systems were chosen primarily
for use in the economic analysis, and are not the only
systems capable of attaining the specified pollutant
reductions.
There are many possible combinations of in-plant and end-of-
pipe systems capable of attaining the effluent limitations,
guidelines and new source performance standards recommended
in this report. However, only one treatment model is
provided in this text for the hospital point source
category.
It is the responsiblity of each individual hospital to make
the final decision about what specific combination of
pollution control measures is best suited to its situation
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in complying with the limitations and standards presented in
this report.
Hospitals
In general, hospital wastes can be readily treated by
biological treatment systems. Although potential does exist
for discharge of biologically inhibiting substances, the
industrial survey indicates that the discharge of such
substances (such as mercury or silver) is not a general
practice. Such substances are usually collected at the
source rather than discharged.
Relatively few hospitals within the United States treat
their own wastewater effluent. Most hospitals are located
in areas of high population density, and consequently, it is
more convenient for them to discharge their wastes to
municipal treatment systems. However, a small number of
hospitals (approximately 500) located in remote areas may
have to treat their own wastes. Among these hospitals the
most prevalent end-of-pipe wastewater treatment system is
the trickling filter plant; however, some activated sludge
systems do exist, as shown in Table VII-1.
In-House Pollution Abatement
During the survey the two most exemplary pollution control
measures observed within hospitals were elimination of
mercury discharge and recovery of silver from spent x-ray
developer. One hospital in particular has gone sc far as to
institute a "no mercury discharge" policy. Waste chemical
compounds or solutions containing mercury are collected in
special containers rather than discarded in a sink. When a
sufficient quantity has been collected, the mercury waste is
then disposed of by a private disposal contractor.
Recovery of silver from spent x-ray developer is practiced
by all hospitals visited during the survey. Larger
hospitals (processing a large number of x-rays) performed
the silver recovery on site, whereas smaller hospitals
drummed their spent developing solutions and returned them
to the manufacturer for resource recovery.
Although many hospitals have active programs aimed at
preventing the discharge of volatile solvents and/or toxic
chemicals to sinks and drains, some are totally unaware of
the potential water pollution problems associated with such
practices. In fact, one hospital was not even aware of the
potential fire hazard associated with discarding volatile
solvents into sinks. Restrictions on the discharge of such
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substances should be an integral part of the operating
procedure for every hospital.
End-Qf-Fipe Control Technology
Table VII-1 indicates the types of wastewater treatment
technology observed during the survey and the treatment
systems identified but not observed. As discussed
previously, approximately ninety-two (92) percent of all
hospitals discharge their wastes to municipal treatment
systems. Those hospitals that treat their wastes generally
use trickling filter systems. Activated sludge systems are
in use at several hospitals and aerated lagoons are utilized
by another hospital.
Table VII-1
Treatment Technology Survey
Type of Number Number
Treatment Observed Identified**
Activated Sludge 1* 1
Trickling Filters 0 11
Aerated Lagoons 0 1
* Hospital No. 93
**Not observed
During the survey program, historical wastewater treatment
plant performance data were obtained when possible. The
historical data were analyzed statistically, and the
performance of individual plants was evaluated. A summary
of the statistical analyses for two of the hospital
wastewater treatment plants is presented in Table VII-2.
The summary of the data presented in Table VII-2 represents
at least a year's operation for plant operations, and
removal efficiencies and effluent concentrations shown
correspond to 90, 50, and 10 percent probability of
occurrence.
During the survey program, 24-hour composite samples over a
two-day period were collected in order to verify historical
performance data and to provide a more complete wastewater
analytical profile. The major purpose for the review of
historical treatment plant performance data was to be able
to guantify BPT reduction factors, which could then be
applied to BPT raw waste load values to develop an end-of-
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Table VI I -2
Summary of Historic Treatment Performance
Hospital
93
102
94*
95*
96*
97*
98*
99*
100*
101*
Type of
Treatment
Activated
Sludge
Activated
Sludge
Tr i ckl i ng
Filter
Trickl ing
Filter
Trickl ing
Filter
Trickl ing
Filter
Trickl ing
Filter
Tr i ckl i ng
Fi Iter
Tri ckl ing
Fi Iter
Trickl ing
Filter
BODc
Removal Eff. (%)
P90 P50 P10
96 95 90
93 92 91
88
92
94
90
98
96
96
76
Effluent
BODt;
mg/L
P90 P50 P10
25 14 10
20 16 12
27
32
11
24
4
11
10
56
Effluent
TSS
mg/L
P90 P50 P10
16 12 8
15 10 6
12
24
8
19
3
12
2
33
*Values based on annual average removal efficiencies
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pipe treatment model. Based on the historical data for
activated sludge treatment plants, a BOD5 treatment
efficiency of 93 percent was established as practical for
the development of EFT treatment technology.
In addition to BOD5r the pollutant to be considered is total
suspended solids (TSS). The model BPT treatment system is
an activated sludge system. Such systems generate
biological solids which must be removed before discharge of
the treated effluent. For this reason, recommendations
concerning TSS were determined from effluent concentrations.
The average discharge of TSS in the effluent of the plants
for which data is available (long term average) is less than
15 mg/1 and easily meets the recommended limitations.
However, a flocculator/clarifier system with coagulant
addition, as is used in other industries, is included in the
cost model to allow for upgrading of existing facilities, if
necessary. This inclusion tends to make the cost model more
conservative since it will not be required by most plants as
indicated by the data.
To assess the economic impact of the proposed effluent
standards, a model activated sludge treatment system was
developed. The end-of-pipe treatment model was designed
based on raw waste load (RWL) data for the hospital point
source category. The primary design parameter in BPT, NSPS
and BAT treatment models is BOD5 removal.
The use of an activated sludge treatment model is done to
facilitate the economic analysis and is not to be inferred
as the only technology capable of meeting the effluent
limitations guidelines and new source performance standards
presented in this report.
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SECTION VIII
COST, ENERGY, AND NON-WATER QUALITY ASPECTS
General
Quantitative cost information for the suggested end-of-pipe
treatment models is presented in the following discussion
for the purpose of assessing the economic impact of the
proposed effluent limitations, guidelines and new source
performance standards. A separate economic analysis of
treatment cost impact on the industry will be prepared by
another contractor and the results will be published in a
separate document.
In the generation of a single product (hospital care) there
is a wide variety of process plant sizes and unit
operations. Many detailed designs might be required to
develop a meaningful understanding of the economic impact of
process modifications. Such a development is really not
necessary, however, because the end-of-pipe models are
capable of attaining the recommended effluent limitations
for the RWL's determined for the category. A design for
end-of-pipe treatment models has been provided for costing
purposes. This can be related directly to the range of
influent hydraulic and organic loading, and the costs
associated with these systems, to show the economic impact
of the system in dollars per 1,000 occupied beds per year.
The combination of in-plant controls and end-of-pipe
treatment used to attain the effluent limitations,
guidelines and new source performance standards presented in
this document should be a decision made by the individual
hospital, based generally upon economic considerations
within the constraints of the requirements of the
limitations.
The major non-water quality consideration associated with
in-process control measures is the means of ultimate
disposal of wastes. As the volume of the process RWL is
reduced, alternative disposal techniques such as in-
cineration, pyrolysis, and evaporation become more feasible.
Recent regulations tend to limit the use of ocean discharge
and deep-well injection because of the potential long-term
detrimental effects associated with these disposal
procedures. Incineration and evaporation are viable
alternatives for concentrated waste streams. Considerations
involving air pollution and auxiliary fuel requirements,
depending on the heating value of the waste, must be
evaluated individually for each situation.
55
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Other non-water quality aspects such as noise levels will
not be perceptibly affected by the proposed wastewater
treatment systems. Equipment associated with in-process and
end-of-pipe control systems would not add significantly to
these noise levels.
An annual and capital cost estimate has been prepared for
the end-of-pipe treatment model to help EPA evaluate the
economic impact of the proposed effluent limitations,
guidelines and new source performance standards. The
capital costs were generated on a 1,000 occupied bed basis
(e.g., equalization, neutralization, etc.) and are reported
in the form of cost curves in Supplement A for all the
proposed treatment systems. The following percentage
figures were added on to the total unit process costs to
develop the total capital cost requirements:
Percent of Unit Process
Item Capital Cost
Electrical 14
Piping 20
Instrumentation 8
Site work 6
Engineering Design and Construction
Surveillance Fees 15
Construction Contingency 15
Land costs were computed independently and added directly to
the total capital costs.
Annual costs were computed using the following cost basis:
Item Cost Allocation
Capital Recovery
plus Return 10 yrs at 10 percent
Operations and Includes labor and supervision.
Maintenance chemicals, sludge hauling and dis-
posal, insurance and taxes (computed
at 2 percent of the capital cost),
and maintenance (computed at 4 per-
cent of the capital cost).
Energy and Power Based on $0.02/kw hr for electrical
power and 172/gal for grade 11
furnace oil.
56
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The 10-year period used for capital recovery is presently
acceptable under current Internal Revenue Service
regulations pertaining to industrial pollution control
equipment.
The following is a qualitative as well as a quantitative
discussion of the possible effects that variations in
treatment technology or design criteria could have on the
total capital costs and annual costs.
Technology or Design Criteria
Use aerated lagoons and 1.
sludge de-watering lagoons
in place of the proposed
treatment system.
Use earthen basins with 2.
compacted clay or clay-
gravel mixes in place
of reinforced concrete con-
struction, and floating
aerators with permanent-
access walkways.
Place all treatment tankage 3.
above grade to minimize
excavation, especially if
a pumping station is re-
quired in any case. Use
all-steel tankage to
minimize capital cost.
Minimize flows and maximize 4.
concentrations through ex-
tensive in-plant recovery and
water conservation, so that
other treatment technologies,
e.g., incineration, may be
economically competitive.
Capital
Cost Differential
The cost reduction
could be 20 to tO per-
cent of the proposed
figures.
Cost reduction could
be 20 to 30 percent
of the total cost.
Cost savings would
depend on the in-
dividual situation.
Cost differential would
depend on a number of
items, e.g., age of
plant, accessibility
to process piping,
local air pollution
standards, etc.
All cost data were computed in terms of August 1972 dollars,
which corresponds to an Engineering News Records index (ENR)
value of 1780. Note that the ENR index value for the year
1975 is 2276.
Hospitals
57
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In order to evaluate the economic impact on a uniform
treatment basis, an end-of-pipe treatment model which will
provide the desired levels of treatment was proposed.
End-of-Pipe
Technology Level Treatment Model
EPT Activated Sludge
EAT Activated Sludge and
Filtration
NSPS Activated Sludge and
Filtration
BPT cost Model
A flow diagram for the BPT wastewater treatment facility for
hospitals is shown in Figure VIII-1. A summary of the
general design basis is presented in Table VIII-1, and the
treatment system effluent requirements are as follows:
Influent (PWL) Effluent
Flow BODS BODS
gal/1,000 lbs/1,000 lbs/1,000
occupied bedsl occupied bedsl occupied bedsl mg/1
319,000 587 41.1 15
(191,000)
1Occupied beds on average annual basis.
The following is a brief discussion of the rationale for
selection of the unit processes included in the model
wastewater treatment system.
Table VIII-1
BPT Treatment Systems Design
Summary
Hydraulic Loading
The model plant was designed for a flow of 191,000 gpd,
59
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Aeration Basin
The size of the aeration basin is based on data collected
during the survey. Mechanical surface aerators are provided
on the following basis:
Minimum Number of Aerators 2
Oxygen Utilization: Energy 0.8 Ibs 0^/lb BOD removed
Oxygen Utilization: Endogenous 6 lbs/hr/1,000 Ibs MLVSS
Alpha Factor 0.75
Beta Factor 0.90
Oxygen Transfer (Standard) 3.5 Ibs 0.2/hr/shaft HP at 20°C
and zero DO in tap water
Motor Efficiency 85 percent
Minimum Basin DO 2 mg/1
Secondary Flocculator/Clarifiers
Secondary flocculatcr/clarifiers are rectangular units with
a length to width ratio of t to 1 and a side water depth of
8 feet. The overflow rate is approximately 450 gpd/sg ft.
Polymer addition facilities are provided.
Chlorination Facilities
Chlorine contact basins have been designed to provide 30
minutes detention time, based on average flow.
Sludge Thickener
The thickener provided was designed on the basis of a solids
loading of 6 Ibs/sq ft/day.
Aerobic Digester
The aerobic digester was designed on the basis of a
hydraulic detention time of 20 days. The size of the
aeration mixers was based on an oxygen requirement of 1.6
Ibs 0.2/lb VSS destroyed and a mixing requirement of 165 HP
per million gallons of digester volume.
Vacuum Filtration
The size of the vacuum filters was based on a cake yield of
2 Ibs/sq ft/hr and a maximum running time of 8 hours per
day. The polymer system was designed to deliver up to 20
Ibs of polymer per ton of dry solids.
60
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BAT Cost Model
The BAT model treatment system used for economic evaluation
of the proposed limitations includes the BPT treatment model
followed by dual-media filtration. A typical flow diagram
for the selected model treatment facilities is shown in
Figure VIII-2. A summary of the general design basis is
presented in Table VIII-2.
Based on effluent filtration data presented in Process
Design Manual for Upgrading Existing Wastewater Treatment
Plants, U.S. EPA, 1974, BAT effluent limitations of 10 mg/1
(22.6 lbs/1,000 occupied beds) for both BOD and TSS are
recommended.
NSPS Cost Model
The NSPS model treatment system is identical to the proposed
BAT treatment system.
An activated sludge process was selected because of its
demonstrated ability to efficiently treat hospital wastes.
Because of the relatively low suspended solids
concentrations, primary clarifiers are not included in the
model facilities. The activated sludge system produces
biological solids which must be removed from the system and
returned to the aeration basin or wasted in order to
maintain the proper load to microorganism ratio. To serve
this purpose, secondary flocculator/clarifiers have been
provided. Sludge handling facilities consisting of
thickening, aerobic digestion, and vacuum filtration have
been provided to facilitate ultimate disposal of sludge to a
sanitary landfill.
Cost
Capital and annual cost estimates were prepared for an end-
of-pipe treatment model. The prepared cost estimates are
presented in Table VIII-3. The costs presented in this
table are incremental costs for achieving each technology
level. The total capital cost for biological treatment to
attain BPT effluent limitations is $830,000 for a hospital
with 600 beds. The BPT effluent limitations were determined
using the reduction factors presented in Section IX. The
incremental capital cost for achieving the recommended BAT
and NSPS effluent limitations for a hospital with 600 beds,
over the cost for BPT, is $169,000. The detailed cost
breakdown by unit processes are included in Supplement A.
61
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Table VIII-2
NSPS Treatment System Design
Summary
Dual-Media Filtration
The size of the filters is based on average hydraulic
loading of 3 gpm/sq ft. Backwash facilities are designed to
provide rates up to 20 gpm/sq ft and for a total backwash
cycle of up to 10 minutes in duration. The filter media are
24" of coal (1mm effective size) 12" of sand (0.4-0.5 mm
effective size).
Backwash Holding Tank
Tankage is provided to hold the backwash water and decant it
back to the treatment plant over a 24-hour period. This
will eliminate hydraulic surging of the treatment units.
The previous cost estimates were prepared based on the
recommended design basis. Variations in the design basis or
selection of alternative treatment processes can have
appreciable effects on the reported capital costs, as
discussed in the "General" part of Section VIII under
"Capital Cost Differential."
Energy
Due to the characteristics of wastewater generated from
hospitals and the high degree of pollutant removal
obtainable by use of activated sludge treatment systems,
application of high energy-consuming processes was not
considered. Therefore, the overall impact on energy for
hospitals should be irinimal. Table VIII-1 presents the cost
for energy and power for the treatment model for BPT, BAT
and NSPS. The details for energy and power requirements are
included in Supplement A.
Non-Water Quality Aspects
The major non-water quality aspects of the proposed effluent
limitations, guidelines and new source performance standards
are ultimate sludge disposal and noise and air pollution.
Ultimate sludge disposal by landfilling for the digested
biological sludge has been proposed. If practiced
correctly, landfilling of the digested biological sludge
does not create health hazards or a nuisance condition.
63
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included in the treatment model due to high cost and high
fuel requirements.
The sludge quantities generated by the treatment model
plants are estimated to be 33,000 Ibs/year on dry solids
weight basis.
Noise level increases due to the implementation of the
proposed treatment model need consideration; however, in the
installations observed, noise levels due to the wastewater
treatment plants were not a problem.
Incineration is not proposed in the treatment model; hence,
air pollution is not of concern.
65
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SECTION IX
BEST PRACTICABLE CONTROL TECHNOLOGY
CUPRENLTY AVAILABLE (BPT)
Hospitals
Based on the information contained in Sections III through
VIII of this report, effluent limitations and guidelines
commensurate with the BPT have been established for
hospitals. The limitations which explicitly set numerical
values for allowable pollutant discharges are presented in
Table IX-1. The effluent limitations and guidelines specify
allowable discharges of BOD5 and TSS based en removals
attainable through application of BPT pollution control
technology described in Section VII of this report. Model
BPT waste treatment technology includes biological treatment
with sludge handling facilities consisting of digestion, de-
watering, and ultimate disposal via a sanitary landfill.
As indicated in Section VII, a BOD5 removal efficiency of 93
percent, based on historical treatment plant data, was
selected as being applicable for the determination of BPT
effluent limitations and guidelines. This technique yields
a BPT long-term average daily effluent of 41.1 Ibs per 1,000
occupied teds for BOD5. The maximum day limitations and the
maximum thirty day limitations are listed in Table IX-1.
See the sample calculation in Section XIII. Promulgation of
effluent TSS limitations based on historical TSS removal
efficiencies is calculated on the basis of a long term
average of 20 mg/1 and the demonstrated levels of daily and
monthly averages based on the same plants for which BOD
calculations were made. The BPT model treatment plant has
teen designed to include a flocculator/clarifier with
polymer addition. Such systems have been shown to be
capable of achieving extremely efficient TSS removal and are
available, if needed, to upgrade existing operations. The
data do not indicate that these systems will be required in
all cases. On this basis, a TSS effluent limitation based
on 20 mg/1 long-term daily average effluent is recommended.
A more severe restriction for total suspended solids can, of
course, be established on the basis of water quality
objectives.
The objective of these effluent limitations and guidelines
is to induce reduction of both flow and contaminant loading
prior to end-of-pipe treatment. However, it is not the
intent of these effluent limitations and guidelines to
specify either the unit wastewater flow which must be
67
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achieved, or the wastewater treatment practices which must
be employed at individual hospitals.
The performance factors used to calculate the BPT effluent
limits presented in Table IX-1 are as follows:
Performance Factors1 Performance Factors1
for Maximum for Maximum
Parameters Monthly Effluent Day Effluent
BOD5 1.8 2.2
TSS 1.i» 2.3
1 99/50 ration of probability
The actual caclulation in terms of pounds of EOD5 or TSS per
1000 occupied beds is demonstrated in Section XIII for BPT
maximum effluent limits.
68
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SECTION X
BEST AVAILABLE TECHNOLOGY ECONOMICALLY
ACHIEVABLE (BAT)
Hospitals
Effluent limitations and guidelines commensurate with the
BAT are presented in Table X-1. BAT effluent limitations
guidelines were developed by evaluating those end-of-pipe
modifications which indicated applicability for achieving
better effluent quality. The BAT effluent limitations and
guidelines are attainable with the end-of-pipe treatment
technology outlined in other areas of this report, which
consists of the addition of dual-media filtration to the
treatment system proposed as EFT technology.
The performance data for dual-media filtration on the
biological treatment plant effluent for hospitals is based
upon the Process Design Manual for Upgrading Existing
Wastewater Treatment Plants by EPA, 1974, and is considered
applicable to the hospital wastewaters. The requirements
are verified by supplement B, containing performance data
for operating systems used by a hospital installation. The
BAT effluent limitations and guidelines are based on this
performance data. A TSS effluent limitation guideline of 10
mg/1 long-term daily average is recommended. The BAT
long-term average daily effluent for BOD5 is 26.6 Ibs per
1,000 occupied beds. After application of the BAT
performance factors to the BAT long-term daily average
value, the iraximum day limitations and the maximum thirty
day limitations for BAT are computed. The results for
regulated parameters are listed in Table X-1. As additional
hospital wastewater treatment plant performance data becomes
available, it may be used to verify the initial judgements.
The following BAT performance factors are proposed for the
following parameters and time intervals:
Performance Factors* Performance Factors1
for Maximum for Maximum
Parameters Monthly Effluent Cay Effluent
BOD5 1.4 1.6
TSS 1.4 1.5
1 95/50 ration of probability
71
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72
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SECTION XI
NEW SOURCE PERFORMANCE STANDARDS (NSPS)
General
The term "new source" is defined in the "Federal Water
Pollution Control Act Amendments of 1972" to mean "any
source, the construction of which is commenced after the
publication of proposed regulations prescribing a standard
of performance". Technology applicable to new sources shall
be the Best Available Demonstrated Control Technology
(NSPS), defined by a determination of what higher levels of
pollution control can be attained through the use of
improved production process and/or wastewater treatment
techniques. Thus, in addition to considering the best in-
plant and end-of-pipe control technology, NSPS technology is
to be based upon an analysis of how the level of effluent
may be reduced by changing the production process itself.
Hospitals
The performance standards commensurate with the BAT are also
recommended as new source performance standards. That is a
TSS effluent limitation guideline based on 10 mg/1 long term
daily average is utilized. The NSPS long-term average daily
effluent for BOD5_ is 26.6 Ibs per 1,000 occupied beds. To
arrive at the maximum day limitations and the maximum thirty
day limitations the respective performance factors are
applied. These performance standards are presented in Table
X-l.
The following NSPS performance factors are proposed for the
following parameters and time intervals:
Parameters
BOD5_
TSS
Performance Factors *
for Maximum
Monthly Effluent
1.4
1.4
Performance Factors
for Maximum
Day Effluent
1.6
1.5
95/50 ration of probability
It must be recognized that, in most cases, in-house
modifications to existing hospitals are interchangeable with
those which can be designed for new ones. Investigations
should be conducted by all types of hospitals to determine
if the wastewaters can be eliminated or reduced in
quantities from their current raw waste loads.
73
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SECTION XII
PFETREATMENT STANDARDS
General
Pollutants from specific processes within this point source
category may interfere with, pass through, or otherwise be
incompatible with publicly owned treatment works (municipal
system). The following section examines the general
wastewater characteristics of the category and the
pretreatment unit operations which may be applicable to the
hospital point source category.
Hospitals
Pollutants from hospitals may interfere with, pass through,
or otherwise be incompatible with a publicly-owned treatment
works. Biochemical oxygen demand, suspended solids, pH, and
fecal coliform bacteria are defined as compatible pollu-
tants, along with other pollutants which publicly-owned
treatment works are designed to remove.
Current regulations governing secondary treatment for
publicly owned treatment works impose the following
limitations for these parameters in 40 CFR Part 133:
(a) Biochemical oxygen demand (five-day) .
(1) The arithmetic mean of the values for effluent
samples collected in a period of 30 consecutive days shall
not exceed 30 milligrams per liter.
(2) The arithmetic mean of the values for effluent
samples collected in a period of seven consecutive days
shall not exceed 45 milligrams per liter.
(3) The arithmetic mean of the values for effluent
samples collected in a period of 30 consecutive days shall
not exceed 15 percent of the arithmetic mean of the values
for influent samples collected at approximately the same
times during the same period (85 percent removal).
(b) Suspended solids.
(1) The arithmetic mean of the values for effluent
samples collected in a period of 30 consecutive days shall
not exceed 30 milligrams per liter.
75
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(2) The arithmetic mean of the values for effluent
samples collected in a period of seven consecutive days
shall not exceed W5 milligrams per liter.
(3) The arithmetic mean of the values for effluent
samples collected in a period of 30 consecutive days shall
not exceed 15 percent of the arithmetic mean of the values
for influent samples collected at approximately the same
times during the same period (85 percent removal).
(c) Fecal coliform bacteria.
(1) The geometric mean of the value for effluent
samples collected in a period of 30 consecutive days shall
not exceed 2CO per 100 milliliters.
(2) The geometric mean of the values for effluent
samples collected in a period of seven consecutive days
shall not exceed 400 per 100 milliliters.
(d) PH.
The effluent values for pH shall remain within the
limits of 6.0 to 9.0.
In-process measures to reduce the quantity and strength of
incompatible pollutants in the wastewater flow can be
beneficial to joint treatment, and should be encouraged.
Pretreatment for the removal of the compatible pollutants is
not required by the federal pretreatment standards.
Pretreatment requirements should be based on an individual
analysis of the permitted effluent limitations placed on a
publicly-owned treatment works and on the potential for
adverse effects on such wastewater treatment works.
The most practicable and economical pretreatment of
incompatible pollutants in hospitals involves in-process
modifications or changes in operating and maintenance
procedures to completely eliminate the pollutants from the
wastewater, rather than end-of-pipe treatment for removal of
these pollutants. Economic advantages can be realized from
in-process removals (i.e., silver recovery), especially in
large hospitals.
The following in-house controls have been reccmmended as
methods of dealing with the pollution problems of hospitals:
1, All x-ray processing units should utilize the
boron-free fixer which is now available from most
manufacturers.
76
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2. Wherever possible, stand-by control units should be
installed on all x-ray processing units to decrease
the usage of water by the processor. In the event
that stand-by controls are not adaptable to the
processing unit, it is recommended that the water
flow be reduced to the minimum input possible
without distracting from the final radiograph.
3. The discharge of silver from x-ray processing units
should be controlled by utilization of a silver
recovery system or by containing the spent
developer and returning it to the manufacturer for
silver recovery. If an in-house silver recovery
system is utilized, it is recommended that recovery
units for heavily-used x-ray processing equipment
be placed in tandem.
4. Because the sources of potential mercury pollution
are varied and complex, the administration should
become familiar with the total mercury problem and
establish staff responsibilities with appropriate
duties.
5. All radioactive waste should be contained and held
until safe to be released to the environment.
Since most hospitals discharge directly to municipal
treatment facilities, pretreatment requirements for their
wastewater discharges are very important. If in-process
modifications and operating procedures are not incorporated
to reduce silver, mercury, and boron from the waste stream,
end-of-pipe pretreatment methods will have to be implemented
to remove or reduce these incompatible pollutants from the
hospital discharge before going to municipal treatment
plants. The pretreatment unit operations which may be
necessary for various types of joint treatment processes are
shown in Table XII-1.
77
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Suspended
Biological
System
Table XII-1
Pretreatment Unit Operations
Fixed
Biological
System
Chemical
Precipitation
(Metals)
+ solids
Separation
Chemical
Precipitation
(Metals)
+ Solids
Separation
Independent
Physical
Chemical
System
Chemical
Precipitation
(Metals)
+ Solids
Separation
Oil and Grease
Skimming
78
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SECTION XIII
PERFORMANCE FACTORS FOR TREATMENT
PLANT OPERATIONS
General
As referenced in the discussion of end-of-pipe treatment
systems in Section VII, the historical treatment plant data
were analyzed on the basis of 50 percent occurrence values
based upon long-term data
All of the factors that bring about variations in treatment
plant performance can be minimized through proper design and
operations. Variations in the performance of wastewater
treatment plants are usually attributable to one or more of
the following:
1. Variations in sampling techniques.
2. Variations in analytical methods.
3. Variations in one or more operational parameters,
e.g., the organic removal rate by the biological
mass, settling rate changes of biological sludge.
4. Controllable changes in the treatability
characteristics of the process wastewaters even
after adequate equalization.
Variability in Biological Waste Treatment Systems
In the past, effluent requirements for wastewater treatment
plants have been related to the achievement of a desired
treatment efficiency based on long term performance. There
are, however, factors that affect the performance and hence,
the effluent quality or treatment efficiency over the short
term is different than the long term performance. Knowledge
of these factors must be incorporated in the development of
effluent limitations to allow for the predictable short term
variations.
The effluent limitations promulgated by EPA and developed in
this document include values that limit both long term and
short term waste discharges. These restrictions are
necessary to assure that deterioration of the nation1s
waters does not occur on a short term basis due to heavy
intermittent discharges, even though an annual average may
be attained.
79
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Some of the controllable causes of variability and
techniques that can be used to minimize their effect
include:
A. Storm Runoff
Storm water holding or diversion facilities should be
designed on the basis of rainfall history and area being
drained. The collected storm runoff can be drawn off at a
constant rate to the treatment system. The volume of this
contaminated storm runoff should be minimized through
segregation and the prevention of contamination. Storm
runoff from outside the plant area, as well as
uncontaminated runoff, should be diverted around the plant
or contaminated area.
B. Flow Variations
Raw waste load variations can be reduced by properly sized
equalization units. Equalization is a retention of the
wastes in a suitably designed and operated holding system to
average out the influent before allowing it into the
treatment system.
C. Spills
Spills of certain materials in the plant can cause a heavy
loading on the treatment system for a short period of time.
A spill may not only cause higher effluent levels as it goes
through the system, but may inhibit a biological treatment
system and therefore have longer term effects. Equalization
helps to lessen the effects of spills. However, long term
reliable control can only be attained by an aggressive spill
prevention and maintenance program including training of
operating personnel. Industrial associations such as the
Manufacturing Chemists Association have developed guidelines
for prevention, control and reporting of spills. These note
how to assess the potential of spill occurrence and how to
prevent spills. If every plant were to use such guidelines
as part of plant waste management control programs, its raw
waste load and effluent variations would be decreased.
D. Climatic Effects
The design and choice of type of a treatment system should
be based on the climate at the plant location so that this
effect can be minimized. Where there are severe seasonal
climatic conditions, the treatment system should be designed
and sufficient operational flexibility should be available
so that the system can function effectively.
80
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E. Treatment Process Inhibition
Chemicals likely to inhibit the treatment processes should
be identified and prudent measures taken to see that they do
not enter the wastewater in concentrations that may result
in treatment process inhibition. The common indicator of
the pollution characteristics of the discharge from a plant
historically has been the long-term average of the effluent
load. However, the long-term (yearly) average is not the
only parameter on which to have an effluent limitation.
Shorter term averages also are needed, both as an indication
of performance and for enforcement purposes.
Wherever possible, the best approach to develop the annual
and shorter term limitations is to use historical data from
the industry in question. If enough data is available, the
shorter term limitations can be developed from a detailed
analysis of the hourly, daily, weekly or monthly data.
Rarely, however, is there an adequate amount of short term
data. However, using data which show the variability in the
effluent load, statistical analyses can be used to compute
short term limits (30 day average or daily) which should be
attained, provided that the plant is designed and run in the
proper way to achieve the desired long term average load.
These analyses can be used to establish variability factors
for effluent limitations or to check those factors that have
been developed.
Hospitals
Historic effluent data from activated sludge plants treating
hospital wastes were statistically analyzed to determine
variability. The results of the analyses are shown in Table
XIII-1. Ratios of the 99 percent probability of occurrence
to the 50 percent probability, the 95 percent to the 50
percent value, and the 90 percent to the 50 percent value
were computed for each hospital. The average ratios are as
follows:
Ratio of BODS TSS
Probability Daily Monthly Daily Monthly
99/50 2.2 1.8 2.3 1.4
95/50 1.6 1.4 1.5 1.4
90/50 1.5 1.2 1.4 1.3
The 50 percent probability of occurrence values and the
maximum daily values shown in Table XIII-1 are based on
analysis of weekly grab sample data over a long period. The
99 percent, 95 percent and 90 percent probability of
81
-------
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occurrence values for the monthly average were based on
"normalized data", that is, data values were assumed to
follow a normal distribution. However, it should be
emphasized that no data points were discarded. The maximum
daily values were not normalized, as adequate long-term data
were available to form definite distribution patterns. The
occurrence of these abnormally high values, causing the
skewing in the data distribution, is indicative of unusually
poor treatment performance, probably caused by some sort of
process upset. Use of 99 percent probability of occurrence
values for BPT results in 99/50 ratios of probability within
a range considered reasonable in statistical analysis of
other treatment plant data for maximum day values. Use of
99 percent probability of occurrence values for establishing
BPT monthly variability is also recommended because use of
99 percent probability suggests that all hospitals in the
point source category could stay within the operating
envelope with minimum or no improvement to its wastewater
treatment.
The values upon which the analysis is based were determined
in the absence of regulations requiring limits on the
effluent and are calculated from an average of many, not
just the more exemplary.
The following performance factors are proposed for the
following parameters and time intervals for BPT:
Performance Factors* Performance Factorsi
for Maximum for Maximum
Parameter Monthly Effluent Day Effluent
BODj> 1.8 2.2
TSS 1.U 2.3
i 99/50 ratio of probability
Although these performance factors are somewhat low in
comparison to values found in other industries, they appear
responsible in view of the fact that waste discharges from
hospitals are relatively continuous and activated sludge
systems treating such wastes are rarely subjected to shock
loadings; hence, their performance tends to be consistent.
83
-------
The following is an illustration of how the EPA regional
offices would employ the performance factors:
BOB 5
lbs./1000
occupied
beds
Average BPT Effluent Limitations 41.1
Max. Day Effluent Adjustment Factor 2.2
Max. Monthly Effluent Adjustment Factor 1.8
Acceptable Maximum for Any One Day 90.4
Acceptable Average of Daily Values
for Any 30 Consecutive Days Shall
Not Exceed
74.0
TSS
lbs./1000
occupied
beds
53.2
2.3
1.4
122.4
74.5
Performance data available from dual-media filtration
treatment systems at this time indicates an extremely low
variability for BAT and NSPS effluent limitations, and the
ratios established for BPT have been used. These ratios may
be reevaluated, if future data indicate a better base is
available.
The adjustment factors in this section were applied to the
long-term average daily effluent limitations to develop the
effluent limitations, guidelines and new source performance
standards as presented in Sections II, IX, X and XI.
84
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SECTION XIV
ACKNOWLEDGEMENTS
This report was prepared by the Environmental Protection
Agency on the basis of a comprehensive study of this
industry performed by Roy F. Weston, Inc., under contract
No. 68-01-2932. The original study was conducted and
prepared for the Environmental Protection Agency under the
direction of Project Director James H. Dougherty, P.E., and
Technical Project Manager Jitendra R. Ghia, P.E. The
following individual members of the staff of Roy F. Weston,
Inc., made significant contributions to the overall effort:
W.D. Sitman P.J. Marks
D.R. Junkins D.A. Baker
D.W. Grogan Y.A. Lin
T.E. Taylor R.R. Wright
M. Ramathan K.M. Peil
The original RFW study and this EPA revision were conducted
under the supervision and guidance of Mr. Joseph S. Vitalis,
Project Officer, assisted by Mr. George M. Jett, Assistant
Project Officer.
Overall guidance and excellent assistance was provided the
Project Officer by his associates in the Effluent Guidelines
Division, particularly Messrs. Allen Cywin, Director, Ernst
P. Hall, Deputy Director, Walter J. Hunt, Branch Chief, and
Dr. W. Lairsar Miller, Senior Technical Advisor. Special
acknowledgement is also made of others in the Effluent
Guidelines Division: Messrs. John Nardella, Martin Halper,
David Becker, Bruno Maier and Dr. Chester Rhines for their
helpful suggestions and timely comments. EGDB project
personnel also wishes to acknowledge the assistance of the
personnel at the Environmental Protection Agency's regional
centers, who helped identify those plants achieving
effective waste treatment, and whose efforts provided much
of the research necessary for the treatment technology
review.
The following individuals supplied input into the
development of this document while serving as members of the
EPA working group/steering committee which provided detailed
review, advice and assistance. Their input is appreciated.
W. Hunt, Chairman, Effluent Guidelines Division
L. Miller, Technical Advisor, Effluent Guidelines Div.
J. Vitalis, Project Officer, Effluent Guidelines Div.
85
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G. Jettr Asst. Project Officer, Effluent Guidelines Civ.
J. Ciancia, National Environmental Research Center,
Edison
H, skovrenek, National Environmental Research Center,
Edison
M. Strier, Office of Enforcement
D. Davis, Office of Planning and Evaluation
C. Little, Office of General Counsel
P. Desrosiers, Office of Research and Development
R. Swank, Southeast Environmental Research Laboratory
Athens
E. Krabbe, Region II
L. Reading, Region VII
E. Struzeski, NFIC, Denver
Appreciation is extended to Mr. Chris Little and James
Rodgers of the EPA Office of General Counsel for their
invaluable contributions and advice.
The American Hospital Association, National Institutes of
Health, and the Veteran's Administration are recognized for
their assistance in the selection of representative
hospitals who provided data relating to RWL and treatment
plant performance.
The cooperation of the individual hospitals who offered
their facilties for survey and contributed pertinent data is
gratefully appreciated. Facilities visited were the
property of the following:
Northport V.A. Hospital (Northport, N.Y.)
Chester Country Hospital (West Chester, Pa.)
National Institutes of Health (Bethesda, Md.)
Furthermore, the project personnel wish to express
appreciation to the following organizations and individuals
for the valuable assistance which they provided throughout
the study:
Joel Zakin, Northport Operations Engineer
Norman W. Skillman, President and Director of Chester
County Hospital
Louis Fragel, Chester county Hospital Engineer
Vinson Oviatt, Chief, NIH Environmental Services Branch
Donald Dunsmore, NIH Environmental Services Branch
Charles Betke, Veterans Administration (Wash., D.C.)
Edward Bertz, Director, Division of Plant Operations,
American Hospital Association
Goodrich Stokes, Assistant Director, Division of Federal
Liaison, American Hospital Association
86
-------
Edwin Hoeltke, American Society of Hospital Engineers
Clyde Sell, Office of Architecture and Engineering, HEW
Acknowledgement and appreciation is also given to Dr. Ray
Loehr for technical assistance, to Ms. Kay Starr and Ms.
Nancy Zrubek for invaluable support in coordinating the
preparation and reproduction of this report, to Ms. Alice
Thompson, Mr. Eric Yunker, Ms. Ernestine Christian, Ms.
Laura Cammarota and Ms. Carol Swann, of the Effluent
Guidelines Division secretarial staff for their efforts in
the typing of drafts, necessary revision, and final
preparation of the revised Effluent Guidelines Division
development document.
87
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SECTION XV
BIBLIOGRAPHY
Hospitals
H-1. "A Survey of a Sewage Treatment Plant at a
Tuberculosis Hospital," U.S. Army Medical Research
and Development Command, June 1959.
H-2. American Hospital Association; Hospital Statistics;
197U.
H-3. "An Evaluation of Persistency for Water Borne
Organics", Hart, F.L., et.al.; A Paper Presented at
the 30th Annual Purdue Industrial Waste Conference,
May 6-8, 1975; Purdue University, West Lafayette,
Indiana,
H-4. "Control of Mercury Pollution," American Hospital
Association, July, 1971.
H-5. DeRoos, R.L., et. al., Water Use in Biomedical
Research and Health Care Facilities, National
Institutes of Health, September 197U.
H-6. "Disposal of Hospital Infectious Solid waste to the
Sewage System" by Jay G. Kremer, et. al.; James M.
Montgomery, Consulting Engineers, Walnut Creek,
California; presented at the Purdue Industrial
Waste Water Conference, May 6-8, 1975.
H-7. "Environmental Health and Safety in Health Care
Facilities", by R. G. Bond, et. al.; University of
Minnesota, MacMillian Publishing Company, Inc.
H-8. Gesell, T.F., et.al., "Nuclear Medicine
Environmental Discharge Measurement", draft Final
Report, University of Texas Health Science Center,
Office of Radiation Programs, U.S.E.P.A.,
Washington, D.C., June, 1975.
H-9. Guide to the Health Care Field, American Hospital
Association, 1974.
H-10. Iglar, A.F. and Bond, R.G., Hospital Solid Waste
Disposal in Community Facilities, a synopsis of 310
articles by Division of Environmental Health,
89
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School of Public Health, University of Minnesota,
EPA Grant No. EC-00261-04, May 1971.
H-11 Me tabolism of Mercury Compounds in Microorganisms,
U.S. Environmental Protection Agency, Ecological
Research Series, EPA-600/3-75-007, October 1975.
H-12. "Physical-Chemical Treatment of Hospital Waste
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H-13. "Results of Survey on Utility Consumption and
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H-14. Singer, R.D., et. al,, "Hospital Solid Waste an
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H-16. Taber* s Cyclopedic Medical Dictionary, 10th
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An Industry View"; Friday, August 22, 1975; pp. A-
1, B-4.
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90
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GR-4 Barnard, J.L.; "Treatment Cost Relationships for
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91
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93
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to Comparative Costs of Sludge Dewatering by Vacuum
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Temperature ajrid the Design and Operation of
Biological Waste Treatment Plants, submitted to the
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Dictionary, 6th Edition; Reinhold Publishing
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94
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GR-49 Sax, N.I.; Dangerous Properties of Industrial
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in Water and Waste Water Laboratories, U.S. EPA
95
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Technology Transfer; EPA, Washington, D.C. 20460;
June, 1972.
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Solids Removal, U.S. EPA Technology Transfer; EPA
625/1-75-003a, Washington, D.C. 20460; January,
1975.
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in Sanitary Sewerage Systems, U.S. EPA Technology
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GR-65 U.S. EPA; Process Design Manual for Sludge
Treatment and Disposal, U.S. EPA Technology
Transfer; EPA 625/1-74-006, Washington, D.C.
20460; October, 1974.
GR-66 U.S. EPA; Effluent Limitations Guidelines and
Standards of Performance, Metal Finishing Industry,
Draft Development Document; EPA 440/1-75/040 and
EPA 440/1-75/040a; EPA Office of Air and Water
Programs, Effluent Guidelines Division, Washington,
D.C. 20460; April, 1975.
GR-67 U.S. EPA; Development Document for Effluent
Limitations Guidelines and Standards of Performance
- Organic Chemicals Industry; EPA 440/1-74/009a;
EPA Office of Air and Water Programs, Effluent
Guidelines Division, Washington, D.C. 20460;
April, 1974.
GR-68 U.S. EPA; Draft Development Document for Effluent
Limitations Guidelines and Standards of Performance
Steam Supply and Noncontact Cooling Water
Industries; EPA Office of Air and Water Programs,
Effluent Guidelines Division, Washington, D.C.
20460; October, 1974.
GR-69 U.S. EPA; Draft Development Document for Effluent
Limitations Guidelines and Standards of Performance
- Organic Chemicals Industry, Phase II Prepared by
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Roy F. Western, Inc. under EPA Contract No. 68-01-
1509; EPA Office of Air and Water Programs,
Effluent Guidelines Division, Washington, D.C.
20460; February, 1974.
GR-70 U.S. EPA; Evaluation of Land Application Systems,
Technical Bulletin; EPA 430/9-75-001; EPA,
Washington, D.C. 20160; March, 1975.
GR-71 U.S. EPA; "Projects in the Industrial Pollution
Control Division," Environmental Protection
Technology Series; EPA 600/2-75-001; EPA,
Washington, D.C. 20460; December, 1974.
GR-72 U.S. EPA; Wastewater Sampling Methodologies and
Flow Measurement Technigues; EPA 907/9-74-005; EPA
Surveillance and Analysis, Region VII, Technical
Support Branch; June, 1974.
GR-73 U.S. EFA; A Primer on Waste Water Treatment; EPA
Water Quality Office; 1971.
GR-74 U.S. EPA; Compilation of Municipal and Industrial
In-jection Wells in the United States; EPA 520/9-74-
020; Vol. I and II; EPA, Washington, D.C. 20460;
1974.
GR-75 U.S. EPA; "Upgrading Lagoons," U.S. EPA Technology
Transfer; EPA, Washington, E.G. 20460; August,
1973.
GR-76 U.S. EPA; "Nitrification and Denitrification
Facilities," U.S. EPA Technology Transfer; August,
1973.
GR-77 U.S. EPA; "Physical-Chemical Nitrogen Removal,"
U.S. EPA Technology Transfer; EPA, Washington, D.C.
20460; July, 1974.
GR-78 U.S. EPA; "Physical-Chemical Wastewater Treatment
Plant Design," U.S. EPA Technology Transfer; EPA,
Washington, D.C. 20460; August, 1973.
GR-79 U.S. EPA; "Oxygen Activated Sludge Wastewater
Treatment Systems, Design Criteria and Operating
Experience," U.S. EPA Technology Transfer; EPA,
Washington, D.C. 20460; August, 1973.
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GR-80 U.S. EPA; Wastewater Filtration Design
Considerations; U.S. EPA Technology Transfer; EPA,
Washington, D.C. 20460; July, 1974.
GR-81 U.S. EPA; "Flow Equalization," U.S. EPA Technology
Transfer; EPA, Washington, D.C. 20460; May, 1974.
GR-82 U.S. EPA; "Procedural Manual for Evaluating the
Performance of Wastewater Treatment Plants," U.S.
EPA Technology Transfer; EPA, Washington, D.C.
20460.
GR-83 U.S. EPA; Pretreatment of_ Pollutants Introduced
Into Publicly Owned Treatment Works; EPA Office of
Water Program Operations, Washington, D.C. 20460;
October, 1973.
GR-84 U.S. Government Printing Office; Standard
Industrial Classification Manual; Government
Printing Office, Washington, D.C. 20492; 1972.
GR-85 U.S. EPA; Tertiary Treatment of Combined Domestic
and Industrial Wastes, EPA-R2-73-236, EPA,
Washington, D.C. 20460; May, 1973.
GR-86 Wang, Lawrence K.; Environmental Engineering
Glossary (Draft) Calspan Corporation, Environmental
Systems Division, Buffalo, New York 14221, 1974.
GR-87 Water Quality Criteria 1972, EPA-R-73-033, National
Academy of Sciences and National Academy of
Engineering; U.S. Government Printing Office, No.
5501-00520, March, 1973.
GR-88 Weast, R., editor; CRC Handbook of Chemistry and
Physics, 54th Edition; CRC Press, Cleveland, Ohio
44128; 1973-1974.
GR-89 Weber, C.I., editor; Biological Field and
Laboratory Methods for Measuring the Quality of
Surface Waters and Effluents," Environmental
Monitoring Series; EPA 670/4-73-001; EPA,
Cincinnati, Ohio 45268; July, 1973.
GR-90 APHA, ASCE, AWWA, and WPCF, Glossary of_ Water and
Wastewater Control Engineering, American Society of
Civil Engineers, New York, 1969.
GR-91 Bailey, W. Robert and Scott, Elvyn G; Diagnostic
Microbiology, 4th Edition; The C.V. Mosby Company,
St. Louis; 1974.
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SECTION XVI
GLOSSARY
Hospitals
Amalgam. Any alloy of mercury with another metal or other
metals. Silver amalgam is used as a dental filling.
Autoclave. A heavy vessel with thick walls for conducting
chemical reactions under high pressure. Also an apparatus
using steam under pressure for sterilization.
Cathartic. A medicine for stimulating evacuation of the
bowels.
Catheter. A slender tube inserted into the body passage,
vessel or cavity for passing fluids, making examinations,
etc.
Culture. A mass of microorganisms growing in a media.
Developer. A chemical used to produce a picture from an
exposed film, plate or printing paper.
Diagnostic Services. The processing or deciding the nature
of a diseased condition by examination of the symptoms.
Diuretic. A drug used to increase the secretion and flow of
urine.
Fixer Solution. A chemical used to render photographic
emulsions insensitive to light.
Geriatric Hospital. A facility that specializes in the
treatment of diseases of old age.
"Hypo". A synonym for fixer solution.
Orthopedic Hospital. A facility that specializes in the
treatment of deformities, diseases, and injuries of the
bones, joints, muscles, etc.
Pathological Wastes. Waste material that is potentially
infected.
Radiograph. A picture produced on a sensitized film or
plate by x-rays.
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Sterilization. The complete destuction of all living
organisms in or on a medium; heat to 121°C at 15 psig for 15
minutes.
Tablet. A small, disc-like mass of medicinal powder used as
a dosage form for administering medicine.
Tissue Fixative. A chemical used to preserve tissue
material for subsequent examination.
Viruses. (1) An obligate intracellular parasitic
microorganism smaller than bacteria. Most can pass through
filters that retain bacteria. (2) The smallest (10-300 urn
in diameter) form capable of producing infection and
diseases in man or other large species. Occurring in a
variety of shapes, viruses consist of a nucleic acid core
surrounded by an outer shell (capsid) which consists of
numerous protein subunits (capsomeres). Some of the larger
viruses contain additional chemical substances. The true
viruses are insensitive to antibiotics. They multiply only
in living cells where they are assembled as complex
macromolecules utilizing the cells* biochemical systems.
They do not multiply by division as do intracellular
bacteria.
General Definitions
Abatement. The measures taken to reduce or eliminate
pollution.
Absorption. A process in which one material (the absorbent)
takes up and retains another (the absorbate) with the
formation of a homogeneous mixture having the attributes of
a solution. Chemical reaction may accompany or follow
absorption.
Acclimation« The ability of an organism to adapt to changes
in its immediate environment.
Acid. A substance which dissolves in water with the
formation of hydrogen ions.
Acid Solution. A solution with a pH of less than 7.00 in
which the activity of the hydrogen ion is greater than the
activity of the hydrcxyl ion.
Acidity. The capacity of a wastewater for neutralizing a
base. It is normally associated with the presence of carton
dioxide, mineral and organic acids and salts of strong acids
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or weak bases. It is reported as equivalent of
because many times it is not known just what acids are
present.
Acidulate* To make somewhat acidic.
Act. The Federal Water Pollution Control Act Amendments of
1972, Public Law 92-500.
Activated Carbon. Carbon which is treated by high-
temperature heating with steam or carbon dioxide producing
an internal porous particle structure.
Activated Sludge Process. A process which removes the
organic matter from sewage by saturating it with air and
biologically active sludge. The recycle "activated"
microoganisms are able to remove both the soluble and
colloidal organic material from the wastewater.
Adsorption. An advanced method of treating wastes in which
a material removes organic matter not necessarily responsive
to clarification or biological treatment by adherence on the
surface of solid bodies.
Adsorption Isotherm. A plot used in evaluating the
effectiveness of activated carbon treatment by showing the
amount of impurity adsorbed versus the amount remaining.
They are determined at a constant temperature by varying the
amount of carbon used or the concentration of the impurity
in contact with the carbon.
Advance Waste Treatment. Any treatment method or process
employed following biological treatment to increase the
removal of pollution load, to remove substances that may be
deleterious to receiving waters or the environment or to
produce a high-quality effluent suitable for reuse in any
specific manner or for discharge under critical conditions.
The term tertiary treatment is commonly used to denote
advanced waste treatment methods.
Aeration. (1) The bringing about of intimate contact
between air and a liquid by one of the following methods:
spraying the liquid in the air, bubbling air through the
liquid, or agitation of the liquid to promote surface
absorption of air. (2) The process or state of being
supplied or impregnated with air; in waste treatment, a
process in which liquid from the primary clarifier is mixed
with compressed air and with biologically active sludge.
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Aeration Period. (1) The theoretical time, usually
expressed in hours, that the mixed liquor is subjected to
aeration in an aeration tank undergoing activated-sludge
treatment. It is equal to the volume of the tank divided by
the volumetric rate of flow of wastes and return sludge.
(2) The theoretical time that liquids are subjected to
aeration.
Aeration Tank. A vessel for injecting air into the water.
Aerobic. Ability to live, grow, or take place only where
free oxygen is present.
Aerobic Biological Oxidation. Any waste treatment or
process utilizing aerobic organisms, in the presence of air
or oxygen, as agents for reducing the pollution load or
oxygen demand of organic substances in waste.
Aerobic Digestion. A process in which microorganisms obtain
energy by endogenous or auto-oxidation of their cellular
protoplasm. The biologically degradable constituents of
cellular material are slowly oxidized to carbon dioxide,
water and ammonia, with the ammonia being further converted
into nitrates during the process.
Algae. One-celled or many-celled plants which grow in
sunlit waters and which are capable of photosynthesis. They
are a food for fish and small aquatic animals and, like all
plants, put oxygen in the water.
Algicide. Chemical agent used to destroy or control algae.
Alkali. A water-soluble metallic hydroxide that ionizes
strongly.
Alkalinity. The presence of salts of alkali metals. The
hydroxides, carbonates and bicarbonates of calcium, sodium
and magnesium are common impurities that cause alkalinity.
A quantitative measure of the capacity of liquids or
suspensions to neutralize strong acids or to resist the
establishment of acidic conditions. Alkalinity results from
the presence of bicarbonates, carbonates, hydroxides,
volatile acids, salts and occasionally borates and is
usually expressed in terms of the concentration of calcium
carbonate that would have an equivalent capacity to
neutralize strong acids.
Alum. A hydrated aluminum sulfate or potassium aluminum
sulfate or ammonium aluminum sulfate which is used as a
settling agent. A coagulant.
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Ammonia Nitrogen. A gas released by the microbiological
decay of plant and animal proteins. When ammonia nitrogen
is found in waters, it is indicative of incomplete
treatment.
Ammonia Stripping. A modification of the aeration process
for removing gases in water. Ammonium ions in wastewater
exist in equilibrium with ammonia and hydrogen ions. As pH
increases, the equilibrium shifts to the right, and above pH
9 ammonia may be liberated as a gas by agitating the
wastewater in the presence of air. This is usually done in
a packed tower with an air blower.
Ammonification. The process in which ammonium is liberated
from organic compounds by microoganisms.
Anaerobic. Ability to live, grow, or take place where there
is no air or free oxygen present.
Anaerobic Biological Treatment. Any treatment method or
process utilizing anaerobic or facultative organisms, in the
absence of air, for the purpose of reducing the organic
matter in wastes or organic solids settled out from wastes.
Anaerobic Digestion. Biodegradable materials in primary and
excess activated sludge are stabilized by being oxidized to
carbon dioxide, methane and other inert products. The
primary digester serves mainly to reduce VSS, while the
secondary digester is mainly for solids-liquid separation,
sludge thickening and storage.
Anion. Ion with a negative charge.
Antagonistic Effect. The simultaneous action of separate
agents mutually opposing each other.
Antibiotic. A substance produced by a living organism which
has power to inhibit the multiplication of, or to destroy,
other organisms, especially bacteria.
Aqueous Solution. One containing water or watery in nature.
Aquifer. A geologic formation or stratum that contains
water and transmits it from one point to another in
quantities sufficient to permit economic development
(capable of yielding an appreciable supply of water).
Aqueous Solution. One containing water or watery in nature.
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Arithmetic Mean. The arithmetic mean of a number of items
is obtained by adding all the items together and dividing
the total by the number of items. It is frequently called
the average. It is greatly affected by extreme values.
Azeotrope. A liquid mixture that is characterized by a
constant minimum or maximum boiling point which is lower or
higher than that of any of the components and that distills
without change in composition.
Backwashinq. The process of cleaning a rapid sand or
mechanical filter by reversing the flow of water.
Bacteria. Unicellular, plant-like microorganisms, lacking
chlorophyll. Any water supply contaminated by sewage is
certain to contain a bacterial group called "coliform",
B at eria, Coliform Group. A group of bacteria, predominantly
inhabitants of the intestine of man but also found on
vegetation, including all aerobic and facultative anaerobic
gram-negative, non-sporeforming bacilli that ferment lactose
with gas formation. This group includes five tribes of
which the very great majority are Eschericheae. The
Eschericheae tribe comprises three genera and ten species,
of which Escherichia Coli and Aerobacter Aerogenes are
dominant. The Escherichia Coli are normal inhabitants of
the intestine of man and all vertbrates whereas Aerobacter
Aerogenes normally are found on grain and plants, and only
to a varying degree in the intestine of man and animals.
Formerly referred to as B. Coli, B. Coli group, and Coli-
Aerogenes Group.
Bacterial Growth. All bacteria require food for their
continued life and growth and all are affected by the
conditions of their environment. Like human beings, they
consume food, they respire, they need moisture, they require
heat, and they give off waste products. Their food
requirements are very definite and have been, in general,
already outlined. Without an adequate food supply of the
type the specific organism requires, bacteria will not grow
and multiply at their maximum rate and they will therefore,
not perform their full and complete functions.
(BADCT) NSPS Effluent Limitations. Limitations for new
sources which are based on the application of the Best
Available Demonstrated Control Technology. See NSPS.
Base. A substance that in aqueous solution turns red litmus
blue, furnishes hydroxyl ions and reacts with an acid to
form a salt and water only.
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Batch Process. A process which has an intermittent flow of
raw materials into the process and a resultant intermittent
flow of product from the process.
(BATEA) BAT Effluent Limitations. Limitations for point
sources, other than publicly owned treatment works, which
are based on the application of the Best Available
Technology Economically Achievable. These limitations must
be achieved by July 1, 1983.
Benthic. Attached to the bottom of a body of water.
Benthos. Organisms (fauna and flora) that live on the
bottoms of bodies of water.
B_io_assay_. An assessment which is made by using living
organisms as the sensors.
Biochemical Oxygen Demand (BOD). A measure of the oxygen
required to oxidize the organic material in a sample of
wastewater by natural biological process under standard
conditions. This test is presently universally accepted as
the yardstick of pollution and is utilized as a means to
determine the degree of treatment in a waste treatment
process. Usually given in mg/1 (or ppm units), meaning
milligrams of oxygen required per liter of wastewater, it
can also be expressed in pounds of total oxygen required per
wastewater or sludge batch. The standard BOD is five days
at 20 degrees C.
Biota. The flora and fauna (plant and animal life) of a
stream or other water body.
Biological Treatment System. A system that uses
microorganisms to remove organic pollutant material from a
wastewater.
Slowdown. Water intentionally discharged from a cooling or
heating system to maintain the dissolved solids
concentration of the circulating water below a specific
critical level. The removal of a portion of any process
flow to maintain the constituents of the flow within desired
levels. Process may be intermittent or continuous. 2) The
water discharged from a boiler or cooling tower to dispose
of accumulated salts.
BOD5. Biochemical Oxygen Demand (BOD) is the amount of
oxygen required by bacteria while stabilizing decomposable
organic matter under aerobic conditions. The BOD test has
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been developed on the basis of a 5-day incubation period
(i.e. BOD5) .
Boiler Slowdown. Wastewater resulting from purging of solid
and waste materials from the boiler system. A solids build
up in concentration as a result of water evaporation (steam
generation) in the boiler.
(BPCTCA) BPT Effluent Limitations. Limitations for point
sources, other than publicly owned treatment works, which
are based on the application of the Best Practicable Control
Technology Currently Available. These limitations must be
achieved by July 1, 1977.
Break Point. The point at which impurities first appear in
the effluent of a granular carbon adsorption bed.
Break Point Chlorination. The addition of sufficient
chlorine to destroy or oxidize all substances that creates a
chlorine demand with an excess amount remaining in the free
residual state.
Brine. Water saturated with a salt.
Buffer. A solution containing either a weak acid and its
salt or a weak base and its salt which thereby resists
changes in acidity or basicity, resists cha.nges in pH.
Carbohydrate. A compound of carbon, hydrogen and oxygen,
usually having hydrogen and oxygen in the proportion of two
to one.
Carbonaceous. Containing or composed of carbon.
Catalyst. A substance which changes the rate of a chemical
reaction but undergoes no permanent chemical change itself.
Cation. The ion in an electrolyte which carries the
positive charge and which migrates toward the cathode under
the influence of a potential difference.
Caustic Soda. In its hydrated form it is called sodium
hydroxide. Soda ash is sodium carbonate.
Cellulose. The fibrous constituent of trees which is the
principal raw material of paper and paperboard. Commonly
thought of as a fibrous material of vegetable origin.
Centrate. The liquid fraction that is separated from the
solids fraction of a slurry through centrifugation.
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Centrifugation. The process of separating heavier materials
from lighter ones through the employment of centrifugal
force.
Centrifuge. An apparatus that rotates at high speed and by
centrifugal force separates substances of different
densities.
Chemical Oxygen Demand (COC). A measure of oxygen-consuming
capacity of organic and inorganic matter present in water or
wastewater. It is expressed as the amount of oxygen
consumed from a chemical oxidant in a specific test. It
does not differentiate between stable and unstable organic
matter and thus does not correlate with biochemical oxygen
demand.
Chemical Synthesis. The processes of chemically combining
two or more constituent substances into a single substance.
Chlorination. The application of chlorine to water, sewage
or industrial wastes, generally for the purpose of
disinfection but frequently for accomplishing other
biological or chemical results.
Clarification. Process of removing turbidity and suspended
solids by settling. Chemicals can be added to improve and
speed up the settling process through coagulation.
Clarifier. A basin or tank in which a portion of the
material suspended in a wastewater is settled.
Clays. Aluminum silicates less than 0.002mm (2.0 urn) in
size. Therefore, most clay types can go into colloidal
suspension.
Coagulation. The clumping together of solids to make them
settle out of the sewage faster. Coagulation of solids is
brought about with the use of certain chemicals, such as
lime, alum or polyelectrolytes.
Coagulation and Flocculation. Processes which follow
sequentially.
Coagulation Chemicals. Hydrolyzable divalent and trivalent
metallic ions of aluminum, magnesium, and iron salts. They
include alum (aluminum sulfate) , quicklime (calcium oxide),
hydrated lime (calcium hydroxide), sulfuric acid, anhydrous
ferric chloride. Lime and acid affect only the solution pH
which in turn causes coagulant precipitation, such as that
of magnesium.
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Coliform. Those bacteria which are most abundant in sewage
and in streams containing feces and other bodily waste
discharges. See bacteria, coliform group.
Ccliform Organisms. A group of bacteria recognized as
indicators of fecal pollution.
Colloid. A finely divided dispersion of one material (0.01-
10 micron-sized particles), called the "dispersed phase"
(solid), in another material, called the "dispersion medium"
(liquid).
Color Bodies. Those complex molecules which impart color to
a solution.
Color Units. A solution with the color of unity contains a
mg/1 of metallic platinum (added as potassium
chloroplatinate to distilled water). Color units are
defined against a platinum-cobalt standard and are based, as
are all the other water quality criteria, upon those
analytical methods described in Standard Methods for the
Examination of Water and Wastewater, 12 ed., Amer. Public
Health Assoc., N.Y., 1967.
Combined Sewer. One which carries both sewage and storm
water run-off.
Composite Sample. A combination of individual samples of
wastes taken at selected intervals, generally hourly for 21
hours, to minimize the effect of the variations in
individual samples. Individual samples making up the
composite may be of equal volume or be roughly apportioned
to the volume of flow of liquid at the time of sampling.
Composting. The biochemical stabilization of solid wastes
into a humus-like substance by producing and controlling an
optimum environment for the process.
Concentration. The total mass of the suspended or dissolved
particles contained in a unit volume at a given temperature
and pressure.
Con duct ivit y. A reliable measurement of electrolyte
concentration in a water sample. The conductivity
measurement can be related to the concentration of dissolved
solids and is almost directly proportional to the ionic
concentration of the total electrolytes.
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Contact Stabilization. Aerobic digestion.
Contact Process Wastewaters. These are process-generated
wastewaters which have come in direct or indirect contact
with the reactants used in the process. These include such
streams as contact cooling water, filtrates, centrates, wash
waters, etc.
Continuous Process. A process which has a constant flow of
raw materials into the process and resultant constant flow
of product from the process.
Contract Disposal. Disposal of waste products through an
outside party for a fee.
Cryogenic. Having to do with extremely low temperatures.
Crystallization. The formation of solid particles within a
homogeneous phase. Formation of crystals separates a solute
from a solution and generally leaves impurities behind in
the mother liquid.
Curie. 3.7 x 1010 disintegrations per second within a given
guantity of material.
Degreasing. The process of removing greases and oils from
sewage, waste and sludge.
Demineralization. The total removal of all ions.
Denitrification. Bacterial mediated reduction of nitrate to
nitrite. Other bacteria may act on the nitrite reducing it
to ammonia and finally N2 gas. This reduction of nitrate
occurs under anaerobic conditions. The nitrate replaces
oxygen as an electron acceptor during the metabolism of
carbon compounds under anaerobic conditions. A biological
process in which gaseous nitrogen is produced from nitrite
and nitrate. The heterotrophic microoganisms which
participate in this process include pseudomonades,
achromobacters and bacilli.
Derivative. A substance extracted from another body or
substance.
Desorption. The opposite of adsorption. A phenomenon where
an adsorbed molecule leaves the surface of the adsorbent.
Diluent. A diluting agent.
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Disinfection. The process of killing the larger portion
(but not necessarily all) of the harmful and objectionable
microorganisms in or on a medium.
Dissolved Air Flotation. The term "flotation" indicates
something floated on or at the surface of a liquid.
Dissolved air flotation thickening is a process that adds
energy in the form of air bubbles, which become attached to
suspended sludge particles, increasing the buoyancy of the
particles and producing more positive flotation.
Dissolved Oxygen (DO) . The oxygen dissolved in sewage,
water or other liquids, usually expressed either in
milligrams per liter or percent of saturation. It is the
test used in EOD determination.
Distillation. The separation, by vaporization, of a liquid
mixture of miscible and volatile substance into individual
components, or, in some cases, into a group of components.
The process of raising the temperature of a liquid to the
boiling point and condensing the resultant vapor to liquid
form by cooling. It is used to remove substances from a
liquid or to obtain a pure liquid from one which contains
impurities or which is a mixture of several liquids having
different boiling temperatures. Used in the treatment of
fermentation products, yeast, etc., and other wastes to
remove recoverable products.
DC Units. The units of measurement used are milligrams per
liter (mg/1) and parts per million (ppm), where mg/1 is
defined as the actual weight of oxygen per liter of water
and ppm is defined as the parts actual weight of oxygen
dissolved in a million parts weight of water, i.e., a pound
of oxygen in a million pounds of water is 1 ppm. For
practical purposes in pollution control work, these two are
used interchangeably; the density of water is so close to 1
g/cm3 that the error is negligible. Similarly, the changes
in volume of oxygen with changes in temperature are
insignificant. This, however, is not true if sensors are
calibrated in percent saturation rather than in mg/1 or ppm.
In that case, both temperature and barometric pressure must
be taken into consideration.
Dual Media. A deep-bed filtration system utilizing two
separate and discrete layers of dissimilar media (e.g.,
anthracite and sand) placed one on top of the other to
perform the filtration function.
Ecology. The science of the interrelations between living
organisms and their environment.
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Effluent. A liquid which leaves a unit operation or
process. Sewage, water or other liquids, partially or
completely treated or in their natural states, flowing out
of a reservoir basin, treatment plant or any other unit
operation. An influent is the incoming stream.
Elution. (1) The process of washing out, or removing with
the use of a solvent. (2) In an ion exchange process it is
defined as the stripping of adsorbed ions from an ion
exchange resin by passing through the resin solutions
containing other ions in relatively high concentrations.
Elutriation. A process of sludge conditioning whereby the
sludge is washed, either with fresh water or plant effluent,
to reduce the sludge alkalinity and fine particles, thus
decreasing the amount of required coagulant in further
treatment steps, or in sludge dewatering.
Emulsion. Emulsion is a suspension of fine droplets of one
liquid in another.
Entrainment Separator. A device to remove liquid and/or
solids from a gas stream. Energy source is usually derived
from pressure drop to create centrifugal force.
Environment. The sum of all external influences and
conditions affecting the life and the development of an
organism.
Equalization Basin. A holding basin in which variations in
flow and composition of a liquid are averaged. Such basins
are used to provide a flow of reasonably uniform volume and
composition to a treatment unit.
Eutrophication. The process in which the life-sustaining
quality of a body of water is lost or diminished (e.g.,
aging or filling in of lakes) . A eutrophic condition is one
in which the water is rich in nutrients but has a seasonal
oxygen deficiency.
Evapotranspiration. The loss of water from the soil both by
evaporation and by transpiration from the plants growing
thereon.
Facultative. Having the power to live under different
conditons (either with or without oxygen).
Facultative Lagoon. A combination of the aerobic and
anaerobic lagoons. It is divided by loading and thermal
stratifications into an aerobic surface and an anaerobic
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bottom, therefore the principles of both the aerobic and
anaerobic processes apply.
Fatty Acids. An organic acid obtained by the hydrolysis
(saponification) of natural fats and oils, e.g., stearic and
palmitic acids. These acids are monobasic and may or may
not contain some double bonds. They usually contain sixteen
or more carbon atoms.
Fauna. The animal life adapted for living in a specified
environment.
Fermentation. Oxidative decomposition of complex substances
through the action of enzymes or ferments produced by
microorganisms.
F i11 e r, T ri ck1inq. A filter consisting of an artificial bed
of coarse material, such as broken stone, clinkers, slate,
slats or brush, over which sewage is distributed and applied
in drops, films for spray, from troughs, drippers, moving
distributors or fixed nozzles. The sewage trickles through
to the underdrains and has the opportunity to form zoogleal
slimes which clarify and oxidize the sewage.
Filter, Vacuum. A filter consisting of a cylindrical drum
mounted on a horizontal axis and covered with a filter
cloth. The filter revolves with a partial submergence in
the liquid, and a vacuum is maintained under the cloth for
the larger part of each revolution to extract moisture. The
cake is scraped off continuously.
Filtrate. The liquid fraction that is separated from the
solids fraction of a slurry through filtration.
Filtration, Biological. The process of passing a liquid
through a biological filter containing media on the surfaces
of which zoogleal films develop that absorb and adsorb fine
suspended, colloidal and dissolved solids and that release
various biochemical end products.
Flocculants. Those water-soluble organic polyelectrolytes
that are used alone or in conjunction with inorganic
coagulants such as lime, alum or ferric chloride or
coagulant aids to agglomerate solids suspended in aqueous
systems or both. The large dense floes resulting front this
process permit more rapid and more efficient solids-liquid
separations.
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Flocculation. The formation of floes. The process step
following the coagulation-precipitation reactions which
consists of bringing together the colloidal particles. It
is the agglomeration by organic polyelectroytes of the
small, slowly settling floes formed during coagulation into
large floes which settle rapidly.
Flora. The plant life characteristic of a region.
Flotation. A method of raising suspended matter to the
surface of the liquid in a tank as scum-by aeration, vacuum,
evolution of gas, chemicals, electrolysis, heat or bacterial
decomposition and the subsequent removal of the scum by
skimming.
Fractionation (or Fractional Distillation). The separation
of constituents, or group of constituents, of a liquid
mixture of miscible and volatile substances by vaporization
and recondensing at specific boiling point ranges.
Fungus. A vegetable cellular organism that subsists on
organic material, such as bacteria.
Gland. A device utilizing a soft wear-resistant material
used to minimize leakage between a rotating shaft and the
stationary portion of a vessel such as a pump.
Gland Water. Water used to lubricate a gland. Sometimes
called "packing water."
Grab Sample. (1) Instantaneous sampling. (2) A sample
taken at a random place in space and time.
Grease. In sewage, grease includes fats, waxes, free fatty
acids, calcium and magnesium soaps, mineral oils and other
nonfatty materials. The type of solvent to be used for its
extraction should be stated.
Grit Chamber. A small detention chamber or an enlargement
of a sewer designed to reduce the velocity of flow of the
liquid and permit the separation of mineral from organic
solids by differential sedimentation.
Groundwater. The body of water that is retained in the
saturated zone which tends to move by hydraulic gradient to
lower levels.
Hardness. A measure of the capacity of water for
precipitating soap. It is reported as the hardness that
would be produced if a certain amount of CaC03 were
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dissolved in water. More than one ion contributes to water
hardness. The "Glossary of Water and Wastewater Control
Engineering" defines hardness as: A characteristic of water,
imparted by salts of calcium, magnesium, and ion, such as
bicarbonates, carbonates, sulfates, chlorides, and nitrates,
that causes curdling of soap, deposition of scale in
boilers, damage in some industrial processes, and sometimes
objectionable taste. Calcium and magnesium are the most
significant constituents.
Heavy Metals. A general name given for the ions of metallic
elements, such as copper, zinc, iron, chromium, and
aluminum. They are normally removed from a wastewater by
the formation of an insoluble precipitate (usually a
metallic hydroxide).
Hydrocarbon. A compound containing only carbon and
hydrogen.
Hydrolysis. A chemical reaction in which water reacts with
another, substance to form one or more new substances.
Incineration. The combustion (by burning) of organic matter
in wastewater sludge.
Incubate. To maintain cultures, bacteria, or other
microorganisms at the most favorable temperature for
development.
Influent. Any sewage, water or other liquid, either raw or
partly treated, flowing into a reservoir, basin, treatment
plant, or any part thereof. The influent is the stream
entering a unit operation; the effluent is the stream
leaving it.
In-Piant Measures. Technology applied within the
manufacturing process to reduce or eliminate pollutants in
the raw waste water. Sometimes called "internal measures"
or "internal controls".
Ion. An atom or group of atoms possessing an electrical
charge.
Ion Exchange. A reversible interchange of ions between a
liquid and a solid involving no radical change in the
structure of the solid. The solid can be a natural zeolite
or a synthetic resin, also called polyelectrolyte. Cation
exchange resins exchange their hydrogen ions for metal
cations in the liguid. Anion exchange resins exchange their
hydroxyl ions for anions such as nitrates in the liquid.
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When the ion-retaining capacity of the resin is exhausted,
it must be regenerated. Cation resins are regenerated with
acids and anion resins with bases.
Lagoons. An oxidation pond that received sewage which is
not settled or biologically treated.
LC 50. A lethal concentration for 50% of test animals.
Numerically the same as TLm. A statistical estimate of the
toxicant, such as pesticide concentration, in water
necessary to kill 50% of the test organisms within a
specified time under standardized conditions (usually 24,48
or 96 hr).
Leach. To dissolve out by the action of a percolating
liquid, such as water, seeping through a sanitary landfill.
Lime. Limestone is an accumulation of organic remains
consisting mostly of calcium carbonate. When burned, it
yields lime which is a solid. The hydrated form of a
chemical lime is calcium hydroxide.
Maximum Day Limitation. The effluent limitation value equal
to the maximum for one day and is the value to be published
by the EPA in the Federal Register.
Maximum Thirty Day Limitation. The effluent limitation
value for which the average of daily values for thirty
consecutive days shall not exceed and is the value to be
published by the EPA in the Federal Register.
Mean. The arithmetic average of the individual sample
values.
Median. In a statistical array, the value having as many
cases larger in value as cases smaller in value.
Median Lethal Dose (LD50). The dose lethal to 50 percent of
a group of test organisms for a specified period. The dose
material may be ingested or injected.
Median Tolerance Limit {TLm). In toxicological studies, the
concentration of pollutants at which 50 percent of the test
animals can survive for a specified period of exposure.
Microbial. Of or pertaining to a bacterium.
Molecular Weight. The relative weight of a irolecule
compared to the weight of an atom of carbon taken as exactly
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12.00; the sum of the atomic weights of the atoms in a
irolecule.
Navigable Waters. Includes all navigable waters of the
United States; tributaries of navigable waters; interstate
waters; intrastate lakes, rivers and streams which are
utilized by interstate travellers for recreational or other
purposes; intrastate lakes, rivers and streams from which
fish or shellfish are taken and sold in interstate commerce;
and intrastate lakes, rivers and streams which are utilized
for industrial purposes by industries in interstate
commerce.
Neutralization. The restoration of the hydrogen or
hydroxyl ion balance in a solution so that the ionic
concentration of each are equal. Conventionally, the
notation "pH" (puissance d'hydrogen) is used to describe the
hydrogen ion concentration or activity present in a given
solution. For dilute solutions of strong acids, i.e., acids
which are considered to be completely dissociate (ionized in
solution), activity equals concentration.
New Source. Any facility from which there is or may be a
discharge of pollutants, the construction of which is
commenced after the publication of proposed regulations
prescribing a standard of performance under section 306 of
the Act.
Nitrate Nitrogen. The final decomposition product of the
organic nitrogen compounds. Determination of this parameter
indicates the degree of waste treatment.
Nit rification. Bacterial mediated oxidation of ammonia to
nitrite. Nitrite can be further oxidized to nitrate. These
reactions are brought about by only a few specialized
bacterial species. Nitrosomonias sp. and Nitrococcus sp.
oxidize ammonia to nitrite which is oxidized to nitrate by
Nitrobacter sp.
Nitrifiers. Bacteria which causes the oxidation of ammonia
to nitrites and nitrates.
Nitrite Nitrogen. An intermediate stage in the decompo-
sition of organic nitrogen to the nitrate form. Tests for
nitrite nitrogen can determine whether the applied treatment
is sufficient.
Ni t r o ba ct er ia. Those bacteria (an autotrophic genus) that
oxidize nitrite nitrogen to nitrate nitrogen.
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Nitrogen Cycle. Organic nitrogen in waste is oxidized by
bacteria into ammonia. If oxygen is present, ammonia is
bacterially oxidized first into nitrite and then into
nitrate. If oxygen is not present, nitrite and nitrate are
bacterially reduced to nitrogen gas. The second step is
called "denitrification."
Nitrogen Fixation. Biological nitrogen fixation is carried
on by a selected group of bacteria which take up atmospheric
nitrogen and convert it to amine groups or for amino acid
synthesis.
Nitrosomonas. Bacteria which oxidize ammonia nitrogen into
nitrite nitrogen; an aerobic autotrophic life form.
Non-contact Cooling Water. Water used for cooling that does
not come into direct contact with any raw material,
intermediate product, waste product or finished product.
Non-contact Process Wastewaters. Wastewaters generated by a
manufacturing process which have not come in direct contact
with the reactants used in the process. These include such
streams as non-contact cooling water, cooling tower
blowdown, boiler blowdown, etc.
Nonputrescible. Incapable of organic decomposition or
decay.
Norma1 Solution. A solution that contains 1 gm molecular
weight of the dissolved substance divided by the hydrogen
equivalent of the substance (that is, one gram equivalent)
per liter of solution. Thus, a one normal solution of
sulfuric acid (H2SOjft, mol. wt. 98) contains (98/2) U9gms of
H2S01 per liter.
NJrDES. National Pollution Discharge Elimination System. A
federal program requiring industry to obtain permits to
discharge plant effluents to the nation's water courses.
NSPS. New source performance standards. See BADCT effluent
limitations.
Nutrient. Any substance assimilated by an organism which
promotes growth and replacement of cellular constituents.
Operations and Maintenance. Costs required to operate and
maintain pollution abatement equipment including labor,
material, insurance, taxes, solid waste disposal, etc.
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Organic Loading. In the activated sludge process, the food
to micoorganisms (F/M) ratio defined as the amount of
biodegradable material available to a given amount of
microorganisms per unit of time.
Osmosis. The diffusion of a solvent through a semipermeable
membrane into a more concentrated solution.
Oxidation. A process in which an atom or group of atoms
loses electrons; the combination of a substance with oxygen,
accompanied with the release of energy. The oxidized atom
usually becomes a positive ion while the oxidizing agent
becomes a negative ion in (chlorination for example) .
Oxidation Pond. A man-made lake or body of water in which
wastes are consumed by bacteria. It receives an influent
which has gone through primary treatment while a lagoon
receives raw untreated sewage.
Oxidation Reduction (OR). A class of chemical reactions in
which one of the reacting species gives up electrons
(oxidation) while another species in the reaction accepts
electrons (reduction). At one time, the term oxidation was
restricted to reactions involving hydrogen. Current
chemical technology has broadened the scope of these terms
to include all reactions where electrons are given up and
taken on by reacting species; in fact, the donating and
accepting of electrons must take place simultaneously.
Oxidation Reduction Potential (ORP). A measurement that
indicates the activity ratio of the oxidizing and reducing
species present.
Oxygen, Available. The quantity of atmospheric oxygen
dissolved in the water of a stream; the quantity of
dissolved oxygen available for the oxidation of organic
matter in sewage.
Oxygen, Dissolved. The oxygen (usually designated as DO)
dissolved in sewage, water or another liquid and usually
expressed in parts per million or percent of saturation.
Ozonation. A water or wastewater treatment process
involving the use of ozone as an oxidation agent.
Ozone. That molecular oxygen with three atoms of oxygen
forming each molecule. The third atom of oxygen in each
molecule of ozone is loosely bound and easily released.
Ozone is used sometimes for the disinfection of water but
more frequently for the oxidation of taste-producing
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substances, such as phenol, in water and for the
neutralization of odors in gases or air.
Parts Per Million (ppm). Parts by weight in sewage
analysis; ppm by weight is equal to milligrams per liter
divided by the specific gravity. It should be noted that in
water analysis ppm is always understood to imply a
weight/weight ratio, even though in practice a volume may be
measured instead of a weight.
Pathogenic. Disease producing.
Percolation. The movement of water beneath the ground
surface both vertically and horizontally, but above the
groundwater table.
Permeabili ty. The ability of a substance (soil) to allow
appreciable movement of water through it when saturated and
actuated by a hydrostatic pressure.
pH. The negative logarithm of the hydrogen ion
concentration or activity in a solution. The number 7
indicates neutrality, numbers less than 7 indicate
increasing acidity, and numbers greater than 7 indicate
increasing alkalinity.
Phenol. Class of cyclic organic derivatives with the basic
chemical formula C6H5OH.
Phosphate. Phosphate ions exist as an ester or salt of
phosphoric acid, such as calcium phosphate rock. In
municipal wastewater, it is most frequently present as
orthophosphate.
Phosphorus Precipitation. The addition of the irultivalent
metallic ions of calcium, iron and aluminum to wastewater to
form insoluble precipitates with phosphorus.
Photosynthesis. The mechanism by which chlorophyll-bearing
plant utilize light energy to produce carbohydrate and
oxygen from carbon dioxide and water (the reverse of
respiration).
Physical/Chemical Treatment System. A system that utilizes
physical (i.e., sedimentation, filtration, centrifugation,
activated carbon, reverse osmosis, etc.) and/or chemical
means (i.e., coagulation, oxidation, precipitation, etc.) to
treat wastewaters.
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Point. Source. Any discernible, confined and discrete
conveyance, including but not limited to any pipe, ditch,
channel, tunnel, conduit, well, discrete fissure, container,
rolling stock, concentrated animal feeding operation, or
vessel or other floating craft, from which pollutants are or
may be discharged.
Pollutional Load. A measure of the strength of a wastewater
in terms of its solids or oxygen-demanding characteristics
or other objectionable physical and chemical characteristics
or both or in terms of harm done to receiving waters. The
pollutional load imposed on sewage treatment works is
expressed as equivalent population.
Polyelectrolytes. Synthetic chemicals (polymers) used to
speed up the removal of solids from sewage. These chemicals
cause solids to coagulate or clump together more rapidly
than do chemicals such as alum or lime. They can be anionic
(-charge) , nonionic (+ and -charge) or cationic (^charge
the most popular). They are linear or branched organic
polymers. They have high molecular weights and are water-
soluble. Compounds similar to the polyelectrolyte
flocculants include surface-active agents and ion exchange
resins. The former are low molecular weight, water soluble
compounds used to disperse solids in aqueous systems. The
latter are high molecular weight, water-insoluble compounds
used to selectively replace certain ions already present in
water with more desirable or less noxious ions.
Population Equivalent (PE). An expression of the relative
strength of a waste (usually industrial) in terms of its
equivalent in domestic waste, expressed as the population
that would produce the equivalent domestic waste. A
population equivalent of 160 million persons means the
pollutional effect equivalent to raw sewage from 160 million
persons; 0.17 pounds BOD (the oxygen demand of untreated
wastes from one person) = 1 PE.
Potable Water. Drinking water sufficiently pure for human
use.
Potash. Potassium compounds used in agriculture and
industry. Potassium carbonate Can be obtained from wood
ashes. The mineral potash is usually a muriate. Caustic
potash is its hydrated form*
Freaeration . A preparatory treatment of sewage consisting
of aeration to remove gases and add oxygen or to promote the
flotation of grease and aid coagulation.
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Precipitation. The phenomenon which occurs when a substance
held in solution passes out of that solution into solid
form. The adjustment of pH can reduce solubility and cause
precipitation. Alum and lime are frequently used chemicals
in such operations as water softening or alkalinity
reduction.
Pretreatment. Any wastewater treatment process used to
partially reduce the pollution load before the wastewater is
introduced into a train sewer system or delivered to a
treatment plant for substantial reduction of the pollution
load.
Primary Clarifier. The settling tank into which the
wastewater (sewage) first enters and from which the solids
are removed as raw sludge.
Primary Sludge. Sludge from primary clarifiers.
Primary Treatment. The removal of material that floats or
will settle in sewage by using screens to catch the floating
objects and tanks for the heavy matter to settle in. The
first major treatment and sometimes the only treatment in a
waste-treatment works, usually sedimentation and/or
flocculation and digestion. The removal cf a moderate
percentage of suspended matter but little or no colloidal or
dissolved matter. May effect the removal of 30 to 35
percent or more BOD.
Process Waste Water. Any water which, during manufacturing
or processing, comes into direct contact with or results
from the production or use of any raw material, intermediate
product, finished product, by-product, or waste product.
Process Water. Any water (solid, liquid or vapor) which,
during the manufacturing process, comes into direct contact
with any raw material, intermediate product, by-product,
waste product, or finished product.
Putrefaction. Biological decomposition of organic matter
accompanied by the production of foul-smelling products
associated with anaerobic conditions.
Pvrolysis. The high temperature decomposition of complex
molecules that occurs in the presence of an inert atmosphere
(no oxygen present to support combustion).
Quench. A liquid used for cooling purposes.
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Raw Waste Load (RWL). The quantity (kg) of pollutant being
discharged in a plant's wastewater. measured in terms of
some common denominator (i.e., kkg of production or m2 of
floor area) .
Receiving Waters. Rivers, lakes, oceans or other courses
that receive treated or untreated wastewaters.
Recirculatipn. The refiltration of either all or a portion
of the effluent in a high-rate trickling filter for the
purpose of maintaining a uniform high rate through the
filter. (2) The return of effluent to the incoming flow to
reduce its strength.
Reduction. A process in which an atom (or group of atoms)
gain electrons. Such a process always requires the input of
energy.
Refractory Organics. Organic materials that are only
partially degraded or entirely nonbiodegradable in
biological waste treatment processes. Refractory organics
include detergents, pesticides, color- and odor-causing
agents, tannins, lignins, ethers, olefins, alcohols, amines,
aldehydes, ketones, etc.
Residual Chlorine. The amount of chlorine left in the
treated water that is available to oxidize contaminants if
they enter the stream. It is usually in the form of
hypochlorous acid of hypochlorite ion or of one of the
chloramines. Hypochlorite concentration alone is called
"free chlorine residual" while together with the chloramine
concentration their sum is called "combined chlorine
residual."
Respiration. Biological oxidation within a life form; the
most likely energy source for animals (the reverse of
photosynthesis).
Retention Time. Volume of the vessel divided by the flow
rate through the vessel.
Retort. A vessel, commonly a glass bulb with a long neck
bent downward, used for distilling or decomposing substances
by heat.
Reverse Osmosis. The process in which a solution is
pressurized to a degree greater than the osmotic pressure of
the solvent, causing it to pass through a membrane.
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Salt. A compound made up of the positive ion of a base and
the negative ion of an acid.
Sanitary Landfill. A sanitary landfill is a land disposal
site employing an engineered method of disposing of solid
wastes on land in a manner that minimizes environmental
hazards by spreading the wastes in thin layers, compacting
the solid wastes to the smallest practical volume, and
applying cover material at the end of each operating day.
There are two basic sanitary landfill methods; trench fill
and area or ramp fill. The method chosen is dependent on
many factors such as drainage and type of soil at the
proposed landfill site.
Sanitary Sewers. In a separate system, pipes in a city that
carry only domestic wastewater. The storm water runoff is
handled by a separate system of pipes.
Screening. The removal of relatively coarse, floating and
suspended solids by straining through racks or screens.
Secondary Treatment. The second step in most waste
treatment systems in which bacteria consume the organic part
of the wastes. This is accomplished by bringing the sewage
and bacteria together either in trickling filters or in the
activated sludge process.
Sedimentation, Final. The settling of partly settled,
flocculated or oxidized sewage in a final tank. (The term
settling is preferred).
Sedimentation, Plain. The sedimentation of suspended matter
in a liquid unaided by chemicals or other special means and
without any provision for the decomposition of the deposited
solids in contact with the sewage. (The term plain settling
is preferred) .
Seed. To introduce microorganisms into a culture medium.
Settleable Solids. Suspended solids which will settle out
of a liguid waste in a given period of time.
Settling Velocity. The terminal rate of fall of a particle
through a fluid as induced by gravity or other external
forces.
Sewage, Raw. Untreated sewage.
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Sewage, Storm. The liquid flowing in sewers during or
following a period of heavy rainfall and resulting
therefrom.
Sewerage. A comprehensive term which includes facilities
for collecting, pumping, treating, and disposing of sewage;
the sewerage system and the sewage treatment works.
Silt. Particles with a size distribution of 0.05mm-0.002mm
(2.0mm). Silt is high in quartz and feldspar.
Skimming. Removing floating solids (scum).
Sludge* Activated. Sludge floe produced in raw or settled
sewage by the growth of zoogleal bacteria and other
organisms in the presence of dissolved oxygen and
accumulated in sufficient concentration by returning the
floe previously formed.
Sludge, Age. The ratio of the weight of volatile solids in
the digester to the weight of volatile solids added per day.
There is a maximum sludge age beyond which no significant
reduction in the concentration of volatile solids will
occur.
Sludge, Digested. Sludge digested under anaerobic
conditions until the volatile content has been reduced,
usually by approximately 50 percent or more.
Solution. A homogeneous mixture of two or more substances
of dissimilar molecular structure. In a solution, there is
a dissolving medium-solvent and a dissolved substance-
solute.
Solvent. A liquid which reacts with a material, bringing it
into solution.
Solvent Extraction. A mixture of two components is treated
by a solvent that preferentially dissolves one or more of
the components in the mixture. The solvent in the extract
leaving the extractor is usually recovered and reused.
Sparger. An air diffuser designed to give large bubbles,
used singly or in combination with mechanical aeration
devices.
Sparging. Heating a liquid by means of live steam entering
through a perforated or nozzled pipe (used, for example, to
coagulate blood solids in meat processing).
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Standard Deviation. The square root of the variance which
describes the variability within the sampling data on the
basis of the deviation of individual sample values from the
mean.
Standard Raw Waste Load (SRWL). The raw waste load which
characterizes a specific sutcategory. This is generally
computed by averaging the plant raw waste loads within a
subcategory.
Stillwell. A pipe, chamber, or compartment with
comparatively small inlet or inlets communicating with a
main body of water. Its purpose is to dampen waves or
surges while permitting the water level within the well to
rise and fall with the major fluctuations of the main body
of water. It is used with water-measuring devices to
improve accuracy of measurement.
Stoichiometric. Characterized by being a proportion of
substances exactly right for a specific chemical reaction
with no excess of any reactant or product.
Stripper. A device in which relatively volatile components
are removed from a mixture by distillation or by passage of
steam through the mixture.
Substrate. (1) Beactant portion of any biochemical
reaction, material transformed into a product. (2) Any
substance used as a nutrient by a microorganism. (3) The
liquor in which activated sludge or other material is kept
in suspension.
Sulfate. The final decomposition product of organic sulfur
compounds.
Supernatant. Floating above or on the surface.
Surge tank. A tank for absorbing and dampening the wavelike
motion of a volume of liquid; an in-process storage tank
that acts as a flow buffer between process tanks.
Suspended Solids. The wastes that will not sink or settle
in sewage. The quantity of material deposited on a filter
when a liquid is drawn through a Gooch crucible.
Svnergistic. An effect which is more than the sum of the
individual contributors.
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Synergistic Effect. The simultaneous action of separate
agents which, together, have greater total effect than the
sum of their individual effects.
Tertiary Treatment. A process to remove practically all
solids and organic matter from wastewater. Granular
activated carbon filtration is a tertiary treatment process.
Phosphate removal by chemical coagulation is also regarded
as a step in tertiary treatment.
Thermal Oxidation. The wet combustion of organic materials
through the application of heat in the presence of oxygen.
TKN (Total K-jeldahl Nitrogen) . Includes ammonia and organic
nitrogen but does not include nitrite and nitrate nitrogen.
The sum of free nitrogen and organic nitrogen in a sample.
Tim. The concentration that kills 50* of the test organisms
within a specified time span, usually in 96 hours or less.
Most of the available toxicity data are reported as the
median tolerance limit (TLm). This system of reporting has
been misapplied by some who have erroneously inferred that a
TLm value is a safe value, whereas it is merely the level at
which half of the test organisms are killed. In many cases,
the differences are great between TLm concentrations and
concentrations that are low enough to permit reproduction
and growth. LC50 has the same numerical value as TLm.
Total Organic Carbon (TOC). A measure of the amount of
carbon in a sample originating from organic matter only.
The test is run by burning the sample and measuring the
carbon dioxide produced.
Total Solids. The total amount of solids in a wastewater
both in solution and suspension.
Total Volatile Solids (TVS). The quantity of residue lost
after the ignition of total solids.
Transport Water. Water used to carry insoluble solids.
Trickling Filter. A bed of rocks or stones. The sewage is
trickled over the bed so that bacteria can break down the
organic wastes. The bacteria collect on the stones through
repeated use of the filter.
Turbidity. A measure of the amount of solids in suspension.
The units of measurement are parts per million (ppm) of
suspended solids or Jackson Candle Units. The Jackson
Candle Unit (JCU) is defined as the turbidity resulting from
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1 ppm of fullerfs earth (and inert mineral) suspended in
water. The relationship between ppm and JCU depends on
particle size, color, index of refraction; the correlation
between the two is generally not possible. Turbidity
instruments utilize a light beam projected into the sample
fluid to effect a measurement. The light beam is scattered
by solids in suspension, and the degree of light attenuation
or the amount of scattered light can be related to
turbidity. The light scattered is called the Tyndall effect
and the scattered light the Tyndall light. An expression of
the optical property of a sample which causes light to be
scattered and absorbed rather than transmitted in straight
lines through the sample.
Volatile Suspended Solids (VSS). The quantity of suspended
solids lost after the ignition of total suspended solids.
Waste Treatment Plant. A series of tanks, screens, filters,
pumps and other equipment by which pollutants are removed
from water.
Water Quality Criteria. Those specific values of water
quality associated with an identified beneficial use of the
water under consideration.
Weir. A flow measuring device consisting of a barrier
across an open channel, causing the liquid to flow over its
crest. The height of the liquid above the crest varies with
the volume of liquid flow.
Wet Air Pollution Control. The technique of air pollution
abatement utilizing water as an absorptive media.
Wet Oxidation. The direct oxidation of organic matter in
wastewater liquids in the presence of air under heat and
pressure; generally applied to organic matter oxidation in
sludge.
Zeolite. Various natural or synthesized silicates used in
water softening and as absorbents.
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SECTION XVII
ABBREVIATIONS AND SYMBOLS
A.C. activated carbon
ac ft acre-foot
Ag. silver
atin atmosphere
ave average
B. boron
Ba. barium
bbl barrel
BOD5 biochemical oxygen demand, five day
Btu British thermal unit
C centigrade degrees
C.A. carbon adsorption
cal calorie
cc cubic centimeter
cfm cubic foot per minute
cfs cubic foot per second
Cl. chloride
cm centimeter
CN cyanide
CCD chemical oxygen demand
cone. concentration
cu cubic
db decibels
deg degree
DC dissolved oxygen
E. Coli Escherichia coliform bacteria
Eq. equation
F Fahrenheit degrees
Fig. figure
F/M BOD5 (Wastewater flow)/ MLSS (contractor volume)
fpm foot per minute
fps foot per second
ft foot
g gram
gal gallon
gpd gallon per day
gpm gallon per minute
Hg mercury
hp horsepower
hp-hr horsepower-hour
hr hour
in. inch
kg kilogram
kw kilowatt
kwhr kilowatt-hour
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L(l) liter
L/kkg liters per 1000 kilograms
Ib pound
m meter
M thousand
me milliequivalent
mg milligram
mgd million gallons daily
min minute
ml milliliter
MLSS mixed-liquor suspended solids
MLVSS mixed-liquor volatile suspended solids
MM million
mm millimeter
mole gram-molecular weight
mph mile per hour
MPN most probable number
mu millimicron
NRC Nuclear Regulatory Commission
NO3> nitrate
NH3-N ammonium nitrogen
-------
TABLE XVIII
METRIC TABLE
CONVERSION TABLE
TIPLY (ENGLISH UNITS) by TO OBTAIN (METRIC UNITS)
ENGLISH UNIT ABBREVIATION CONVERSION ABBREVIATION METRIC UNIT
e ac
e-feet ac ft
.tish Thermal
nit BTU
.tish Thermal
nit/Pound BTU/lb
do feet/minute cfm
>ic feet/second c£s
)ic feet cu ft
)ic feet cu ft
)ic inches cu in
pree Fahrenheit °F
it ft
.Ion gal
.Ion/minute gpm
rsepower hp
;hes in
:hes of mercury in Hg
mds Ib
.lion gallons/day mgd
.e mi
jnd/square
Inch (gauge) psig
aare feet sq ft
oare inches sq in
i (short) ton
d yd
0.405
1233.5
0.252
ha
cu m
kg cal
0.555
0.028
1.7
0.028
28.32
16.39
0.555 (°F-32)*
0.3048
3.785
0.0631
0.7457
2.54
0.03342
0.454
3,785
1.609
kg cal/kg
cu m/min
cu m/min
cu m
1
cu cm
°C
m
1
I/sec
kw
cm
atm
kg
cu in/day
km
(0.06805 psig +1)* atm
0.0929
6.452
0.907
0.9144
sq m
sq cm
kkg
m
hectares
cubic meters
kilogram-calories
kilogram calories/kilogram
cubic meters/minute
cubic meters/minute
cubic meters
liters
cubic centimeters
degree Centigrade
meters
liters
liters/second
killowatts
centimeters
atmospheres
kilograms
cubic meters/day
kilometer
atmospheres (absolute)
square meters
square centimeters
metric ton (1000 kilograms)
meter
* Actual conversion, not a multiplier
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