Reference Publications

NAT'L INST. OF l 81-2210

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Onsite Wastewater Systems — Current

Practices and a Proposed Basis for

Evaluation

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March 1981

Fred Winter

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81-2210

1981

'enter for Building Technology

*ational Engineering Laboratory

.S. Department of Commerce

ational Bureau of Standards

Washington, DC 20234

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NBSIR 81-2210

*40 ONSITE WASTEWATER SYSTEMS - CURRENT

PRACTICES AND A PROPOSED BASIS FOR

EVALUATION

JUL 2 0 1981

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Fred Winter

Center for Building Technology

National Engineering Laboratory

U.S. Department of Commerce

National Bureau of Standards

Washington, DC 20234

March 1981

Prepared for Department of Housing and Urban Development

Division of Energy, Building Technology and Standards

Office Policy Development and Research

Washington, DC 20410

U.S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director
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TABLE OF CONTENTS

Page

PREFACE iii

ABSTRACT iv

ACKNOWLEDGMENTS v

1. INTRODUCTION 1

2. PROJECT DESCRIPTION 3

2.1 Project Objectives 3 2.2 Project Scope 3

3. CLASSIFICATION OF ONSITE WASTEWATER ELEMENTS AND SYSTEMS 5

4. DOCUMENTATION OF THE ONSITE WASTEWATER SYSTEMS REVIEWED 8

5. ONSITE WASTEWATER SYSTEMS EVALUATION BASIS 30

5 . 1 Performance Criteria ....... 30

5.2 Classification of Site Conditions and Rating of Onsite

Systems . 31

5.3 System Selection Based on Site Conditions 31

6 . REQUIREMENTS FOR DEMONSTRATION PROJECTS 40

7 . RECOMMENDATIONS ... 44

7.1 Recommendation of Wastewater Systems for Demonstration 44

7 . 2 Recommendation for Research 47

BIBLIOGRAPHY 50

REFERENCES 53
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TABLE OF CONTENTS (Continued)

Page

APPENDIX 55

A. COMPILATION OF ONSITE WASTEWATER SYSTEMS 56

SUMMARY OF THE FIELD TRIPS 59

DISCUSSION OF WASTEWATER SYSTEMS AS VIEWED FROM THE FIELD TRIPS 70

C.l Composting Toilets 70

C.2 Chemical Toilets 71

C.3 Incinerating Toilets 71

C.4 Vacuum Toilet System 72

C.5 Aerobic Systems 73

C.6 Mounds 74

C. 7 E-T Beds 75

D. ONSITE WASTEWATER DEMONSTRATION PROJECTS 79

E. SOME ASPECTS OF ONSITE WASTEWATER TOPICS 84

E.l The Aspect of the User’s Acceptance 84

E.2 The Aspect of Acceptance by Codes 84

E.3 The Aspect of Health 87

E.4 The Aspect of Maintenance 94

E.5 Economic Aspects 94

E.6 The Aspects of Soil Evaluation 96

E. 7 Grey Water Systems 98

F. ADDITIONAL SOURCES OF INFORMATION ON ONSITE WASTEWATER SYSTEMS 101

F. l Literature 101

F.2 Conferences Related to Onsite Wastewater Systems 102

F.3 Organizations Dealing With Onsite Wastex^ater Systems 102

F.4 Manufacturers Marketing Wastewater Package Plants 102
LIST OF TABLES

Page

Table 1. Matrix of Onsite Wastewater System vs. Site Conditions .... 32

Table 2. List of Input Parameters for Onsite Wastewater System

Evaluation 33

Table 3. Proposed Rating Criteria for Onsite Wastewater Elements ... 34

Table 4. Application of a Rating Scheme for Onsite Wastewater

Elements 35

Table 5. Site Conditions Appropriate to the Onsite Wastewater

Devices 36

Table 6. Proposed Timetable for Onsite Wastewater Project 43

Table 7. Wastewater Devices Observed or Reviewed in the Project .... 56

Table 8. Absorption Area Requirements for a Single Family Residence

Comparison Between Septic Tanks and Aerobic Tanks 74

Table 9. Failure or Malfunction of Systems Reviewed 76

Table 10. Results of the Survey on Attitudes Towards Recycled

Wastewater Conducted by "Pure Cycle" 85

Table 11. Public Attitude Ratings Toward Reuse for Various Usages - Conducted by the State of California ...................... 86

Table 12. Relative Frequencies for Reasons of Nonacceptance of Full

Reuse of Reclaimed Water - Conducted by the State of

California 86

Table 13. Maximum and Minimum Values for Areas of Septic Tank Soil

Absorption Systems Required by State Codes 88

Table 14. State Onsite Wastewater Policies 89

Table 15. Wastewater Disease Outbreaks in 1971-1975 93

Table 16. Etiology of Waterborne Disease Outbreaks in 1971-1975 93

Table 17. Waterborne Disease Outbreaks by Type of System

in 1971-1975 93

Table 18. Waterborne Disease Outbreaks by Type of Deficiency 93

Table 19. Distribution of Wastewater Loading Between Grey and

Black Water 99

x
LIST OF FIGURES

Page

1. Classification of Onsite Wastewater System Elements 7

2. Large Type Compost Toilet 9

3. Small Type Compost Toilet 9

4. Oil Flush Toilet System 11

5. Incinerating Toilet 12

6. Packaging Toilet 12

7. Suds Toilet 14

8. Vacuum Drainage and Vacuum Toilet 15

9. The Microphor Toilet 17

10. The Macerator Toilet 17

i 11. European Flush Down Toilet 18

12. Pressurized Tank Toilet 18

13. Septic Tank 20

14. Aerobic Tank 21

15. Rotor Disc 21

16. Recirculating Sand Filter 23

17. Sewage Electro Osmosis 24

18. Mound System 26

19. Evapotranspiration Bed 26

20. Grey Water Recirculation for Toilet Reuse 29

21. USDA Soil Textural Classification 97

22. Clivus Multrum Grey Water Filter 100

23. University of Wisconsin Grey Water Filter 100
PREFACE

This report is one of a group documenting National Bureau of Standards

(NBS) research and analysis efforts in developing water conservation test

methods, models for technical and economic analysis, and strategies for

implementation and acceptance of practices. This work is sponsored by the

Department of Housing and Urban Development, Office of Policy Development

and Research, Energy, Building Technology and Standards Division, under

Interagency Agreement H-48-78.

Certain trade names and company products are identified in this report.

In no case dees such identification imply that the products are necessarily

the best available for the purpose for which they were mentioned.

iii
ABSTRACT

A review of onsite wastewater systems and wastewater recirculation/reuse

devices based on the literature and field inspections of systems in actual

settings and usage is presented. Based upon the observations, an evaluation

basis for onsite wastewater systems is proposed. Criteria and requirements

for conducting and monitoring demonstration projects is presented. Wastewater

systems identified as potentials for demonstration projects are suggested.

Topics requiring further study are identified and recommended for specific

research.

Key Words: Onsite wastewater systems; wastewater disposal; wastewater

recirculation; wastewater reuse; wastewater treatment;

water conservation.

IV
ACKNOWLEDGMENTS

Appreciation is hereby expressed to the following organizations and persons who

devoted their time and provided the investigator with information and material

for this report:

o Larry Waldorf from the Appalachian Regional Commission, Washington, D.C.

o David Salisbury from Boyd County, Kentucky

o William Hill from Valley Septic Products, Gettysburg, Pennsylvania

o Lyman Schooley from Montgomery County, Maryland, EPA

o Frank Reeves from R. M. Thornton, Inc., Washington, D.C.

o Curtis Bohlan from the Eastern Environmental Controls, Maryland

o J. Tailor from the Virginia Highway Department

o Bill Johnson and Bill Armstrong from N.C. Highway Department

o Dr. R. Carlile and R. Rubin from North Carolina State University

o Stanley Thompson, Sperryville, Virginia

o Merril B. Glasser from the Department of Health, Maryland

o Gunar and Heather Baldwin, Thornton Gore Enterprises, New Hampshire

o Eugene Moreau from the Department of Human Services, Maine

o William Bullard from Thetford Corporation, Michigan

o Jay Bastion from the Department of Transportation, Michigan

o Jerry Tyler, Bob Siegriest and Dean Cliver from the University of Wisconsin,

Madison, Wisconsin

o Mark Palmer and Binx Selbey from Pure Cycle, Boulder, Colorado

o Mike Whitmore from Boulder County Department of Health, Boulder, Colorado

o Dr. Foresti and Mr. Bowl from the Eton Water Cyk, Maryland

o Dick McCulloh from "AQUA SAVER," Maryland

v

1 . INTRODUCTION

The needs for innovative onsite wastewater systems and wastewater reuse devices

as means for solutions to oroblems immerging from conventional centralized

wastewater systems and septic tanks, has been expressed and documented in

numerous publications. The following facts are cited in reports, research

papers and surveys related to this topic:

o One third of the population in the United States live in homes with septic

tanks for wastewater treatment systems. Failure of these systems result in

a nuisance to the homeowners or to the occupants of the adjacent dwellings

and/or hazards to the environment by polluting the ground water and other

sources of water supply.

o A large portion of the land in the United States has soils of marginal

characteristics and is not suitable for septic tanks and wastewater soil

absorption systems.

o The high and rising costs of gravity sewers and centralized wastewater

systems call for alternatives for the reduction of the overall costs of

housing.

o Increase in demand for water and the depletion of potable water resources,

in particular, in the Southwest call for water conservation measures.

o A trend of the population to moving to rural areas where centralized

systems cannot be reached and onsite wastewater treatment is the only

solution to the household wastewater treatment and disposal problems.

o Sewage moratoria in suburban areas hinders the development of such communities and unreasonably escalates the cost of land to which services are available

.

The material reviewed, communications with professionals, and field observations

revealed the growing needs for innovative onsite wastewater systems in this

country. Methods are therefore required to provide an evaluation basis of

existing technologies and newly developed devices and equipment for onsite

wastewater systems.

Within the past two decades, information and experience has been accumulated for

onsite wastewater systems and system elements such as soil absorption systems,

aerobic treatment units and low flush toilets, through research, demonstration

projects, and actual usage. It appears that the greatest need is to collect and

classify the findings into well defined test cases where systems successes and

failures can be analyzed and general conclusions drawn for future references.

However, more research is required in several disciplines of onsite wastewater

systems to arrive at conclusions and issues that are still debatable and are subject to opinions in the absence of a finalized scientific data base. Further

work is required to establish a data base on systems reliability and limitations,

systems suitability to specific site conditions, systems economic feasibility

1
and the aspect of health of onsite wastewater systems. This material is

essential for the code writing groups so that they have adequate information

for incorporating innovative onsite wastewater systems in the building codes,

and for the legislative agencies throughout the country so that they have

a sufficient degree of confidence for approving innovative onsite wastewater

systems. Topics and problem areas, identified in the course of this project

are described in Chapter 7.

2
2 . PROJECT DESCRIPTION

2 . 1 Project Objectives

The tasks undertaken in the project had the following objectives:

- Documentation of the state of the art of onsite wastewater systems and

water recirculation/reuse devices.

- Develop recommendations to establish a basis for systems evaluation.

Provide guidelines for HUD in selection of systems for demonstration.

- Identify problem areas in onsite wastewater systems for future

investigation

2 . 2 Scope of Activities Carried Out

Literature Search

The literature search revealed that a large number of works have been

written in the subject of onsite wastewater systems. The material

Reviewed for this project is cited in the sections of bibliography,

references, and Appendix F.l of this report.

Conferences and Seminars Attendance (see Appendix F.2)

Visits to Research Organizations

The visits to research organizations were conducted for the purpose

of observing the testing facilities and the ongoing research programs

in onsite wastewater systems (see Appendix F.3)

Visits to Manufacturing Plants (see Appendix F.4)

Visits to County and State Health Departments

Visits to health departments were for the purpose of studying the

personnel’s attitude towards innovative wastewater systems, policies

regarding the approval of systems, viewing field inspection procedures

and observing the performance of wastewater systems under their

jurisdiction.

3
2.2.3 Field Trips

Field trips were conducted to closely observe innovative wastewater systems in

actual operation. Information was obtained on the degree and frequency of the

required maintenance, repairs and the needs for replacements of parts.

Operational problems and failures of onsite systems were experienced. The

trips furnished the opportunity for studying the advantages and disadvantages

of various installations and their applicability to various site conditions.

Conversations with the homeowners and occupants furnished information on the

user's attitudes and user's acceptance of innovative wastewater systems. As

witnessed, assessment on the performance of the systems can only be attained

through extensive field inspections where onsite wastewater systems are observed

in "real life" situations.

Field trips were made in states in the East, the Midwest, and the State of

Colorado. The field trip findings were documented in 25 field trip reports

and their summary is described in Appendix B.

This activity has provided the broadest and most significant source of

information and illuminated the following aspects in innovative onsite

wastewater systems:

a. Problems of operation and maintenance.

Breakdown of moving parts, malfunction of systems controls and

unavailability of replacement parts.

b. Problems of users acceptance.

Innovative wastewater systems are not readily accepted primarily because

of lack of proper preparation and education.

c. Problems of improper design.

Improper system design yielded inefficient performance, frequent

breakdowns and/or prohibitive costs of operation.

d. Problems of proper choice of system to the requirements of the site

conditions

.

Systems failure because considerations were not given to the particular

site conditions and/or systems limitations.

e. Problems in onsite wastewater demonstration projects.

Demonstration projects and their problems as witnessed in the field trips are described in Appendix D.

4
3 . CLASSIFICATION OF ONSITE WASTEWATER ELEMENTS AND SYSTEMS

Onsite wastewater management starts from the water supply to the household and

ends xtfith the final disposal of the treated wastewater effluents. The system

may incorporate a wastewater package which handles all the undergoing stages

of the process, or it may include one or more elements for eliminating the

particular problem at the site.

Figure 1 and the following outline represent a general breakdown of the elements

to be considered in onsite wastewater systems.

I. Water Supply System

o Community (municipality) supply system

o Onsite (well) supply system

o Onsite wastewater recirculation/reuse

o Water conservation appliances and fixtures

II. Generation of Wastewater

Input: from fixtures and appliances

Output: to drains, sewer lines

o Black Water - Wastewater from the water closet (W.C.) and kitchen sink

o Grey Water - All wastewater excluding the wastes from the water closet

and kitchen sink

III . Wastewater Treatment

Input: from drain lines, sewers Output: to treatment unit, i.e., septic tank, aerobic unit, sand filter,

disinfection

o Blackwater Treatment

o Greywater Treatment

o Combined Treatment

IV. Wastewater Disposal

Input: from treatment unit

Output: transport lines and disposal systems

o Ground disposal, i.e., soil absorption systems,

o Surface disposal, i.e., creeks, lakes, rivers, oceans,

o Atmospheric disposal, i.e., evapotranspiration systems,

o Elimination, i.e., incineration,

o Transfer, i.e., transfer to centralized locals.

5
V. Wastewater Recovery

o Recirculation of effluencts - water reuse for:

Grey water for gardening

Grey water for toilet reuse

- Grey water for potable reuse

- Black water for water closet

Combined water for water closet

Combined water for gardening

o Recovery of nutrients (compost)

o Recovery of energy (methane)

i

6
Water Supply System

~T

l

I

I

I J

Figure 1. Classification of Onsite Wastewater System Elements.

7
4. DESCRIPTION OF ONSITE WASTEWATER SYSTEMS (1)

A brief description of the systems and their principles of operation is

presented. The description of the following systems is based on manufacturers

catalogs, technical publications and information obtained by the investigator

from his field trips. This study provided a basis for recommendations of some

of these systems for onsite wastewater demonstration projects. The inherent

advantages and disadvantages of some of these systems are described in Chapter 7.

4 . 1 Toilets

Composting Toilets

Composting toilets operate on the principle of biological aerobic decomposition. This process takes place by various species of aerobic microorganisms

that thrive in the environment as long as air is present in the organic waste

material. These organisms digest the waste materials and in the process break

up the organic wastes to deliver a humus-like odorless product. For proper

performance, the system requires air circulation, moisture, temperature of at

least 35 C and a carbon to nitrogen ratio of approximately 30.

Composting toilets are classified into "large type" and "small type".

The Large Type Composting Toilet (Fig. 2) In the large type system, the

wastes from the toilet fall into a tank of approximately 120 cubic feet

generally located in the basement. A garbage chute to the tank is normally

installed in the kitchen for the disposal of all the organic kitchen wastes.

The tank contains air ducts and a vent which extends to the roof for air

circulation. Peat moss or saw dust must occasionally be added to the tank

for maintaining a satisfactory level of the carbon/nitrogen ratio. The

decomposed wastes are occasionally removed from the tank at a frequency which

depends on its usage. An ordinary usage of a family of four, may not require

emptying the tank for at least one year. The decomposed products may be used

as fertilizers for gardening.

The Small Type Composting Toilet (Fig. 3) In the "small type" system, the

toilet wastes fall in the container directly under the toilet. The system

has approximate overall dimensions of 120 cm (length) x 50 cm (width) x 60 cm

(height) (40 x 20 x 25 inches)

.

Air is mechanically supplied by a fan with the vent extended through the roof.

The temperature in the tank is controlled by a heating coil of ordinarily 130

watts and a thermostat to maintain a temperature level (35 C) in the wastes.

Some models also have a humidity control device for maintaining the moisture

level in the tank. Decomposed material is scrubbed off by a rod and fall into

a tray for periodic removal. Due to the relatively small size of the tank the

system is less stable as compared to the "large volume" type and requires more

frequent maintenance. Improper balance of the air flow, humidity, temperature

This description presents an overview of the systems studied. No attempt

was made to evaluate a particular product, but mainly to describe the

inherent features and the principles of operation, of the presently

available systems.

8
Air Vent

Kitchen Chute Toilet

Air

Optional

Mid-section

Figure 2

Large Type Compost Toilet

Figure 3

Small Type Compost Toilet

(Source: The Mulbank)

9
and organic matter ratio may cause foul odors, flies and rapid accumulation of

liquids in the tank. A new model which has recently reached the market operates

at higher temperatures and powers a mixing device which loosens up the waste

matter in the composting chamber for a more efficient supply of oxygen in the

system.

The Carousel Toilet The Carousel toilet is similar to the large type composting

toilet since the wastes drop to a holding composting tank located under the

toilet. The tank is circular and contains four chambers. Depending on its

frequency of usage the tank is periodically rotated so that each chamber collects

the incoming wastes separately. A family of four may need to rotate the

composting chamber once in six months. According to the manufacturers specifications, the system requires a 150 mm (6 in) vent, a fan and a 150 watt heater.

Oil Flush Toilets (Fig. 4) This system utilizes mineral oil as a flushing

medium which is recirculated in a closed system. The system is composed of an ordinary toilet (one company uses teflon coated toilets for better rinse

and scour action) a holding tank, pumps and a series of filters. After

flushing the toilet, the wastes settle to the bottom of the tank and the oil

is recirculated through the filters back to the W.C. tank. The oil in the

system is disinfected by chlorine tablets prior to filtration. The filters

must be periodically replaced and a small percentage of oil replenished. The

wastes are periodically pumped out, hauled to a processing plant or incinerated

on site. Up to the present time, these systems have been limited for use only

in public places, such as highway rest areas and park facilities.

Chemical Toilets Chemical toilets are generally designed for recreational

areas and vehicles but have also been used to a limited extent in homes. All

chemical toilets operate by chemically degrading the incoming waste matter by

the insertion of a biodegradable chemical agent to the fixed quantity of water

in the bowl. The small portable type can be used for twenty applications

after which the decomposed wastes are disposed of. Larger models are recirculating systems utilizing a filter and a recirculating pump where

flushing of the bowl takes place after each usage. These systems may be used

for 80 flushes before requiring disposal and recharge of a new chemical dose.

Incinerating Toilets Incinerating toilets have had some use in homes. Their

applicability is limited because of high energy cost; in addition, foul odors

may be produced while the wastes are being incinerated.

Incinerating Toilets - Gas Fired When the seat cover of the toilet is raised

the hopper flap opens, permitting the waste matter to fall into the incinerating chamber, at which time, a vent in the rear of the unit opens for air

circulation through the system. Upon closing the seat cover, the hopper flap

closes, an igniter coil generates a spark igniting the fuel gas which burns

up the bowl's contents. The system normally requires a 1/4 lb. of propane

gas per usage. Incinerating time is approximately 10 minutes.

Incinerating Toilets - Electricity Operated (Fig. 5) Incineration involves

an electrical heating element which typically draws 2400 watts for ten minutes.

Some systems require a longer time for complete incineration (up to 40 minutes)

however, the incinerating cycle may be interrupted, and the system used, before

10
RESTROOM FIXTURES

Figure 4

The Oil Flush Toilet Svstem

11
Ignition

Power Burner

Blower Assembly

Exhaust

Blower

Assembly

Packaged Wastes

Figure 6

Packaging Toilet

12
termination of the previous incineration occurred. The systems reviewed

require a plastic liner which must be placed in the bowl before usage. (The

cost of this plastic liner is approximately 8q-per usage.)

Packaging Toilets (Fig. 6) Packaging toilets are used in Sweden and Norway

in recreational areas and summer homes. A long plastic foil is placed in the

toilet. The wastes drop into this foil and are sealed by heat to form leakproof

sausage-like packages. Fourty usages are available for one continuous foil,

after which a new cassette is placed in the toilet. The electrical requirements for the system amount to one kilowatt hourzfor 3400 packaging operations.

Provisions must be made for the disposal of the packaged wastes.

Freezing Toilets Freezing toilets are in use in Norway. The toilet contains

a 6 gallon bag to store the wastes which are kept frozen and consequently

produce no odors. The heat removed as part of the freezing process is transferred to the seat for the user's comfort. Provisions must be made for the

disposal of the wastes.

Suds Operated Toilets (Fig. 7) The suds operated toilet, a Japanese invention,

operates on a principle of constant release of a foaming surfactant to obtain

cleansing of the bowl. This material, claimed to be biodegradable, is stored

in a small tank located on the toilet and is used for continuously sudsing the

rear section of , the bowl. Flushing takes place upon pushing a button to

actuate an electro-magnetic foaming device to completely cover the toilet

surface with suds; the "foam" solution continues to flow down the toilet and

seals off odor by filling the space around a synthetic rubber flap valve (in

lieu of a water filled trap) . In its external features this plastic toilet

which requires one cup of water per flush, is similar in appearance to a regular water closet. The toilet may be installed in an apartment building

requiring no venting since there is no water trap seal. The installation uses

a special holding tank which contains a hopper which collects the wastes and

all grey water is piped into that holder. When the wastewater in the hopper

reaches about two gallons, the hopper is tilted and evacuates the contents

into the drain pipe with sufficient water sweeping. This system has been used

in Japan successfully according to the manufacturer's claim.

Vacuum Toilets Sewage System (Fig. 8) This system consists of a uniquely

designed toilet, drainage system, vacuum pumps, and a vacuum collecting tank.

The system is maintained at a partial vacuum of 380 mmHg. The toilet contains

a mechanism where by flushing takes place with the opening of the drainage

line, and drawing water and contents of the bowl by suction to the tank. The

toilet requires two quarts per flush. The system has its advantages in its

substantial reduction of water and its independency of topography since the

transport medium is by vacuum action as compared to the conventional gravity

fed sewer system. Its shortcomings are in its dependency on maintaining

vacuum, generation of high noise level at the time of the toilet’s flush,

succeptibility to blockages due to the small diameter of the drainage system

and succeptibility to failure of the flush valve due to its complex, intricate

mechanism.

13
Figure 7

The Suds Water Closet

14
Figure 8

Vacuum Toilet System

15
The Microphor Toilet (Fig. 9) This toilet uses two liters (a half gallon) of

water per flush, and operates with the following flush cycle: Upon actuating

the flush mechanism, a flapper valve in the toilet opens and the wastes with

the initial water in the bowl drop into a chamber at a low point in the

toilet. The chamber is then air pressurized to 50 psi from a pressure tank

and forces the wastes out. The cycle is terminated with the water seal trap

refill. The components of the system are: a ceramic toilet similar in

appearance to an ordinary water closet, an actuating mechanism, a compressor

and a pressure tank.

Hacerator Toilet (Fig. 10) The flush cycle is initiated upon depressing a flush button. A pump creates vacuum in the system to draw the wastes into

the toilet chamber, where maceration of the solids by a cutting wheel takes

place. The slurry is then evacuated through a small one inch pipe through a two inch trap seal down stream. The system requires one and one-half liters

of water. The toilet housing resembles a compost toilet in its external

features and contains a stainless steel bowl under which the macerator pump

and waste trap are situated.

Pressurized Tank Toilet (Fig. 11) Pressurized tank toilets operated by a compressor system or utilize the pressure of the household water supply

thereby increasing the available energy for flushing, as compared to the

conventional toilet tank where the available potential energy is a function

of the head of water in the tank. Several toilet configurations are at

present available. A system observed has an ordinary bowl. With the pressurized compressor tank, the toilet requires only eight liters (two gallons) per

flush. A Canadian firm markets a plastic toilet. Aside from its tank which

is pressurized by the water supply existing pressure, it has other features

such as a flush nozzle to direct the wastes to its outlet and a chamber to

which the water and wastes enter before evacuation. The chamber also contains

the seal trap. This toilet requires only four liters (one gallon) per flush

and has been approved by the Canadian Standards Association.

Two Step Flush Water Closet A mechanism is inserted in the conventional

water closet tank which enables selective flushing of either all the water

contents in the tank or a partial quantity: according to the needs, thus

enabling saving of water up to 40 percent as compared to the ordinary toilet.

European Wash Down Toilets (Fig. 12) European Wash Down Toilets are used

throughout the world. They usually require 9 liters (2 1/2 gallons) of water

per flush. A new type manufactured by Ifo in Sweden requires three liters

(less than one gallon) per flush. European toilets operate on the principle

of weir action where the water coming from the rim builds up a hydraulic

head to create a weir action, contrary to the common American toilets which

operate by syphonic action utilizing a large hydraulic head and a more

effective flush resulting in a more superior cleansing action as compared to

the flush down toilets. Syphonic toilets, however, require a larger quantity

of water primarily for the inducement of the syphonic action. They typically

require 19 liters (5 gallons) and the relatively new Water Saver types

require up to 15 liters (4 gallons)

16
Microphor Toilet

Figure 10

Macerator Toilet

17
* Figure 11

Pressurized Tank Toilet

Figure 12

A Typical European Flush Down Toilet

18
4 . 2 Wastewater Treatment Systems

Septic Tanks - Anaerobic Treatment System (Fig. 13) Septic tanks are the

simplest onsite wastewater treatment systems in their design, installation,

and operation. The primary purpose of the septic tank is to protect the soil

absorption system from becoming clogged by solids suspended in the raw wastewater. This is accomplished by the design of the tank which provides a chamber

for the retention of the settleable and floatable material; and affects the

outflow of relatively clear effluents to the soil absorption field. The

anaerobic environment in the tank enables the decomposition and partial treatment of the wastewater by the anaerobic organisms which naturally thrive in the

wastewater influents. Most tanks have a similiar construction and they vary

primarily by their size, which in all codes in the country is determined by the

number of the bedrooms in the house. The septic tank is the most economical

means of onsite wastewater treatment and functions adequately provided the soil

underlying the absorption field has the properties for acting as a wastewater

filtration medium and for handling the wastewater hydraulic loading.

Aerobic Treatment Units (Fig. 14) Aerobic wastewater systems decompose the

wastewater pollutants by aerobic microorganisms. Aerobic systems of all forms

have some mechanical means to maintain a level of dissolved oxygen thereby

enabling aerobic organisms to thrive in their natural surroundings, feed on the wastewater nutrients and decompose the sewage. It has been established

that among the pertinent parameters evaluated in wastewater systems the

reduction in biochemical oxygen demand (B.O.D.), the aerobic process is more

efficient as compared to the anaerobic process in septic tanks. It has been

claimed and demonstrated that the soil absorption systems are better maintained

when subjected to effluents from aerobic systems.

Flow Through Type Aerobic Units This is a simple form of aerobic treatment

where air is continuously diffused in the wastewater chamber for maintaining

a level of dissolved oxygen (D.O.) in the range of 2-3 ppm.

Batch Type Aerobic Units Several system configurations are available. In

principle the system contains process control devices for a 24 hour operating

cycle which includes aeration, quiescent period and a pump out. This is a more efficient process as compared to the flow through type, in particular,

for the prevention of solids carry over resulting in hydraulic surges. Its

shortcoming is in its susceptibility to malfunctions of its control mechanisms.

Rotor Disc - Aerobic Units (Fig. 15) The system is composed of a shaft and

a series of discs partially submerged in the wastewater which continuously

rotates at a slow speed of 3 rpm. The discs provide a large contact area for

bacteriological growth. Results indicate a high performance efficiency in the

removal of wastewater parameters such as B.O.D., suspended solids, nitrogen

and phosphates.

19
INSPECTION .-PORTS

Figure 13

Septic Tank

20
Figure 14

Aerobic Tank (Batch Type)

(Source: Eastern Environmental Controls Inc.)

Figure 15

Rotor Disc Unit

(Source: CMS Rotor Disc)

21
4.3 Sand Filters

Sand filters have been used as effective wastewater systems, in particular,

for achieving a water quality acceptable for surface discharge. The treatment

of the incoming wastewater is achieved in the upper sand layers where a biological mat is formed. The effluents leaving the filter undergo disinfection

before final discharge. The most common parameter for measuring the filter's

performance is the present B.O.D. removal which normally range in values from

75 to 95 percent. The predominant parameter of the filter are the sand grains

size and size distribution defined as "effective size" and "uniformity

coefficient." The effective size will determine the wastewater loading rates

expressed in gallons per day per square foot (gal/day/sq. ft), the frequency of

required maintenance, namely, the removal of the clogged upper layers and the

present B.O.D. reduction. Several sand filter configurations have been in use.

The Buried Sand Filter A bed is excavated and underlain collector pipes are installed. A layer 30 cm (1 ft.) of gravel is placed followed by a layer of

sand 90 cm (3 ft.). Drain tile is then placed and covered by gravel 30 cm

(1 ft.). The bed is then covered by top soil. The capacity of systems of

that type range from three to six liters (0.75 to 1.5 gallons) per day per

square foot.

The Recirculating Sand Filter (Fig. 16) The system consists of a septic tank,

a sand filter and a recirculating tank. The wastewater from the septic tank

flows to the recirculating tank from which it is pumped to the filter and

recycled back to the recirculating tank. Thus, every quantity of wastewater

makes several passes going from the recirculation tank and back to the filter

reducing the level of pollutants in each cycle. It has been claimed, although

data was not found in the literature, that the performance of this system as compared to an ordinary sand filter, is more reliable in delivering treated

effluents of consistant degree of effluent quality.

4.4 The Sewage Electro-Osmosis System (Fig. 17) The sewage electro-osmosis

system is constructed for increasing the infiltration rate of septic tank

effluents into soils composed of heavy clays which otherwise would fail as wastewater absorption systems. As explained by its inventor [1], the system

creates an electric field in the soil and by electrolysis, a dissociation

of the water into hydrogen and oxygen. The hydrogen is liberated from the

soil and sewage effluent. The oxygen in the soil maintains aerobic conditions

for aerobic wastewater digestion in addition to the increase infiltration rate

down the soil strada.

The system is constructed as follows:

Adjacent and parallel to the trench line, a hole 120 x 60 x 90 cm (4 x 2 x 3 ft.)

is prepared and filled with dolomite rock. This rock column makes up the anode

of the system. Some 30 feet away, a second hole is dug and filled with carbon

and 120 cm (4 ft.) graphite piles. This column makes up the cathode. In the

electrolytic process, the oxygen flows towards the anode to the trench region.

The system hardly requires any maintenance and proved to be very effective. Up

to the present, these systems were installed only in the western states.

22
,raw sewage

float

valve

Miter effluent

•water

level at time

of discharge

open sand filter

.underdrain

bleed- wi _

line ^r

^) . recirculating pump

•recirculation tank

Figure 16

Recirculating Sand Filter

23
T

T: Leaching trench

A: Rock filled anode

C: Carbon filled calhode

ST: Effluents from septic tank

Figure 17

Sewage Electro-Osmosis

24
4 . 5 Soil Absorption Systems

Failure of septic tank systems usually manifests itself by seepage of the

septic tank effluents to the ground causing the contamination of the ground

water or sewage backup in the house plumbing because of soil clogging. System

failure is then attributed to the soil absorption system rather than the septic

tank itself. Thus, the soil absorption system should have the capability of

handling the hydraulic loading in transporting the effluents into the ground

and the capability to purify the effluents to some acceptable degree. If the

underlying soil meets the above criteria, conventional septic tanks and tile

fields work well, otherwise, the following alternatives are at present in use

for soil absorption systems.

Multiple Alternating Soil Absorption Fields Soil clogging and crusting result

from continuous i^astewater loading. "Resting” of the clogged drain fields

allows for at least a partial restoration of the soil absorption system to its

initial permeability. A design of a multiple alternating fields which diverts

the effluent intermit tantly by a planned sequential schedule may restore and

rejuvenate systems which otherwise would have failed.

The Mound System (Fig. 18) Mound systems have been in use for several years.

They are constructed to meet the following problems in the existing soil stratum:

- Slowly permeable soils

- Shallow permeable soils over creviced bed rock

- Permeable soils with high water tables

The mounds are so designed and sized that they can handle the daily wastewater

flows without surface outflow and that the basal area, which is the natural

soil area beneath the mound will be sufficiently large to conduct the effluent

into the underlying top soil. A clean medium size sand is used as the fill

material and gravel is used in the trenches in which the perforated pipe

network is laid. Top soil covers the upper zone of the mound. Best results

are obtained with pressurized mounds where the effluents are pumped and

injected under low pressures (2-3 psi) . This assures even distribution of

effluents throughout the mound.

4 . 6 Wastewater Disposal Through The Atmosphere

Evapotranspiration Beds (Fig. 19) Evapotranspiration (E-T) beds are designed

for soils which are composed of very heavy clays where the percolation rates

cannot meet the effluent hydraulic loads or in areas where no effluent soil

infiltration is allowed. The beds are constructed by excavating an area to

approximately two feet deep. The area is enveloped by a plastic sheet and

filled with a layer of gravel, sand and top soil on which vegetation is grown.

The operation of E-T systems may be critical as it relies totally on the

balance between the incoming effluent loads, precipitation and evapotranspiration

which consists of transpiration, the movement of water through the plants to

the atmosphere and evaporation, the movement of water vapor from the soil to

the air.

Mechanical Rotating Discs Evaporation This system is composed of a series of

discs partially immersed in the effluents holding tank. The discs which

rotate at a low speed provide a large surface area for evaporation. The

25
Figure 18

Mound System

Figure 19

Evapotranspiration Bed (cross-section)

26
diameter of the disc typically is six feet and the length of the total unit

is 19 feet. As compared to E-T beds, this system requires a smaller area and is

less dependent on precipitation. Being a mechanical system, its susceptibility

to mechanical failures, in particular, breakage of the disc’s shaft is the

disadvantage of the system. This system is limited to regions where freezing

conditions do not occur.

Surface Discharge-Spray Irrigation Surface irrigation as a means for disposal

are used by more than 1300 sewage treatment plants throughout the country and

were also observed in individual onsite wastewater systems. The application

of this method is also dependent on the infiltration rate of the surface

layer, slope and depth of water table. Important consideration must be given

to the spread of microorganisms through the air as an aerosol or the deposit

on plants and vegetable, therefore, spray irrigation is usually preceded by

disinfection. Positive use of irrigation is attained by the utilization of

the dissolved nutrients in wastewater for the benefits of the irrigation crops.

4 . 7 Lagoons

Lagoons are used for treating effluents of small communities. Lagoons are classified according to their mode of operation. Oxidation ponds are dependent

primarily upon photosynthesis for maintaining an oxygen content in the effluents.

Aerated lagoons operate by aeration with mechanical means. Anaerobic lagoons

digest the wastewater effluent by anaerobic processes. For onsite systems,

aerated lagoons are probably most suitable. Lagoons require maintenance and

observation as their ongoing processes are very much dependent on climatic

changes which effect their microorganismic ecosystem and consequently, the mode

and degree of the wastewater treatment.

4 . 8 Wastewater Recycling and Reuse Systems

Black Water Recycling for Toilet Flush Water Reuse

Several publications report on self contained recirculation toilets. No

prorietary product of relatively simple hardware was found on the market.

McGill University has done research on wastewater recirculating toilets where

the wastewater decomposition would be accomplished by continuous aeration,

however the results were not satisfactory. It is probably difficult to attain

a reliable system with that mode of operation unless advanced and expensive

hardware is incorporated.

Black and Grey Water Recycling for Toilet Flush Water Reuse Only one wastewater package designed to treat black and grey water to a quality which is

appropriate for effluent recirculation was observed in operation. The system

entails three basic components to carry out the processes, ultra filtration

for the removal of fine suspended particles and a water polishing process for

disinfection by a U/V light and carbon treatment for the removal of odor. The

system produces a very clear effluent with extremely low turbidity. (See Field

Trip No . 16)

27
Grey Water Recirculation for Toilet Flush Water Reuse (Fig. 20) Several

systems are available. The mode of operation is similar in all the presently

available types and involves the collection of all the household grey water

into a holding tank (except for the kitchen sink wastes) filtration and

disinfection by iodine or chlorine. The system includes back flow prevention

devices to guard against grey water flowing to the potable water supply,

overflow to the drainage system and stand-by provisions from the water supply

source, should the recycled grey water be depleted. This type of treatment

is probably adequate from a health stand point, however residues of particles

remain unfiltered and causes turbidity of visible magnitude, in the recycled

water in the water closet bowl which has a greyish appearance (as observed in

the field trips)

.

Total Wastewater Treatment - Recirculation and Reuse for Potable Water Only

one system which treats wastewater to the degree rendered to be of potable

quality was reviewed and observed in operation. Details on the processes are

in Field Trip Report No. 19. At present the company manufactures one model

for single family homes only. The system utilized advanced technology

including microprocessing for monitoring. The quality of the water produced

is high and from the data observed, meets and surpasses the requirement of

any known code. The cost of this system is relatively moderate, however, the

company will construct this system subject to the condition that at least 150

individual units are built in a radius of 50 miles. In that case a center is

formed from which servicing, operation and maintenance are provided.

28
Figure 20

Grey Water Recirculation for Toilet Reuse

(Source: Aqua Saver)

29
5. ONSITE WASTEWATER SYSTEM EVALUATION BASIS

5 . 1 Performance Criteria

Performance criteria for onsite systems must address the following requirements

in order to attain acceptability by the regulatory bodies and the homeowners:

Adequate Effluent Quality

System Reliability

Aesthetic Acceptability

Simplicity

Economic Feasibility

Specifications for the above requirements vary from system to system depending

on both the intended functional performance of the systems and the local

regulatory requirements. Several standards for specific systems exist such

as NSF Standard 40 for individual aerobic wastewater treatment plants [2] and

NSF Standard 41 for wastewater reuse systems [3]. The need for performance

standards for all types of systems exists; however, as systems vary in design,

intent of usage and configuration, it is more plausible to require test data

from manufacturers on the capability of the system in the following categories:

1. Effluent Quality

Expected effluent quality from the system and range of critical values

of the pertinent effluent parameters.

2. System Reliability

Mechanical reliability of the system and its components, susceptibility

to stress and shock loading, means of system control.

3. Aesthetic Acceptability

Description of features which require special maintenance and change

in user’s habits.

4. Simplicity

Simplicity in operation and replacement of parts. Information should

be provided whether the system is designed to be maintained by the

homeowner, by an ordinary plumber, or requires a maintenance contract

with the manufacturer.

5. Economic Feasibility

Cost of the system (i.e., of design, acquisition, construction, energy/

fuel, maintenance, replacement of parts).

30
With the above performance information, a decision can be made as to the

suitability of the system in meeting specific requirements such as water

consumption, B.O.D. loading, turbidity, maximum cost, etc.

5 .

Classification of Site Conditions and Rating of Onsite Systems

Two considerations must be anticipated in establishing the basis for systems

evaluation: They are

Given the site conditions, what is the most appropriate system to be

selected for the site?

Given a wastewater system, under what site conditions will it function

effectively?

This dual problem may be represented as in Table 1 where the horizontal

entries list all the possible site conditions (S^, S„..S.) and the vertical

entries represent the available wastewater systems (0 , d^..O.) such that the

figure N. . represent the rating of system j as applied to sit^ condition i.

Such an undertaking, however, is too difficult to obtain as it involves too

many considerations that cannot be expressed by one unique rating. The

following tables are therefore constructed instead:

Table 2 lists the site conditions to be considered for onsite system installation. Table 3 lists the wastewater system's attributes to be considered for

system selection. Three rating levels are ranked, for which "A" is considered

as "very favorable" and "C" regarded as "not favorable."

In Table 4, the ratings of the wastewater systems reviewed are presented. This

scheme is very general. Some attributes such as "water saving" and "reduction

in blackwater" can be quantified while most others are subject to judgement

and qualitative assessment. In addition, each system must be viewed from its

intended use perspective. A system may be too costly for an individual home;

however, when applied to a multifamily setting or a cluster of homes it may be

regarded as cost effective. For example, the reliability of Evapotranspiration

(E-T) beds was rated as "B" in Table 4, E-T systems perform well in arid

regions but are susceptible to failure in cold, high precipitation regions.

As an illustration, the following information can be drawn from Table 4 on the

vacuum toilet system: Relatively expensive, provides for about 50 percent in

water saving, nearly 100 percent in black water reduction, poor record of

acceptability, requires special construction considerations, and not acceptable

by codes.

5 . 3 System Selection Based on Site Conditions

Table 5 lists some of the systems reviewed and identifies site conditions for

which these systems are likely to perform adequately.

31
Table 1

Matrix of Onsite Wastewater System Selection

vs. Site Conditions

System 0^

Site Conditions S.

x

1 2 i •

1

2

3

•

•

3 N. ,

•

•

•
Table 2. List of Input Parameters for Onsite Wastewater

System Evaluation

PARAMETER SITE CONSIDERATIONS

I. Geography - Climate Cold, moderate, warm

Humid, dry

Precipitation: low, medium, high

II. Home Setting Rural remote, rural, suburban, urban

III. Means of Wastewater Disposal

1. Degree of Disposal No disposal, limited means for

disposal, available disposal

2. Point of Discharge Ground, creek, potable body of water,

recreational body of water, ocean, sewer

IV. Availability of Water Resources Wqter shortage, adequate water supply

V. Home Layout

1. Lot size

2. Lot topography

3. Soil conditions

Small, medium, large

Level ground, moderately slop, steep

Slowly permeable soil, shallow permeable

soil over bedrock, permeable soil with

high watertable

VI. Demography

1. Population size

(number of homes)

2. Family size

3. Population density

4. Population forecast

1, 2-5, 6-20, 20-100, over 100 families

1, 2, 4, 8

Sparce, moderately dense, dense

Decreasing, stable, increasing

VI. Population Background

1. Population income

2. Population education

Very low, low, medium, high

Low, medium, high

VII. Prospect for construction or extension of a central system

No prospect, connection to a central

system in five years

33
Table 3

Proposed Rating Criteria for Onsite Wastewater Elements

Parameter to be Rated Rating Criteria

A B C

1. Economic Consideration- Cost Subject to - Initial cost, acquisition, shipment

and installation

- Maintenance

- Replacement of parts

- Running cost

- Overhaul cost

- Disposal cost

- Energy recovery

Establish basis such as annual cost,

from which relative rating is derived. Low Cost Medium Cost

- High Cost r1

2. Water Saving 100% 50% no saving -

3. Reduction of Blackwater 100% 50% no reduction

4. Reduction of Greywater 100% 50% no reduction

5. User’s Acceptance subject to:

noise, odor, appearance,

visitor’s reaction

highly

acceptable

Acceptable

with

reservations

questionable

6. Requirements for routine

maintenance and service

Equivalent to

5 min/month

or less

Equivalent

to

20 min/month

Equivalent

to

1 hr/month

7. Requirements for periodic

system check

no requirementonce a monthonce a week

8. System reliability subject to:

Safety, health hazard, susceptible

to shock loads, dependability on specialized personnel, and

availability of replacement parts.

Highly

reliable

reasonably

reliable questionable

:

y

9. Special requirements on design

(to accommodate system)

no special

requirements

Some design

considerations

Major design

consideration

10. Market Availability

(system and parts)

readily

available

reasonably

available

May require

3 month wait -

11. Product stage of development

A consumer

product

Well developed

innovative

system

Experimental

limited field

data

12. Code Acceptance Accepted by

most major

codes

started

gaining

acceptance

no acceptance _

34
Table 4

Application of a Rating Scheme for Onsite Wastewater Elements

ATTRIBUTES

SYSTEM

-u

CO 0O

/ s

0c

0o

u:

00 c>

CO onc

01

4.1

c

o c

>» 0

CJ 3 U

3

V TJ ^

OS <V Q;

•-)

<v w

Xt 4l -C i eg Lj -x a a

<J Qj <0 QJ (J

L, (j as c -r

ai Cl c

C0 c

01 C 0/ Cj CO 3

3: t

<V c •— u > 3 L. C 3

oc cn

>

-c

rp

a> or

0) x c

s» O

4:C 3 X •-» U c

4J

•f £ • 1

-c - ^

-j c a

^ o £ CJ

<r cc

1. Compost Toilet - Large Volume B B A - B B B A A C B

2. Compost Toilet - Small Volume A B A - B C C B A B C

3. Oil Flush Toilets C B A - C C C C B C c

4. Chemical Toilet A B A - C B A A A A c

5. Microphor Toilets A B B - B B B A A B A

6. Incinerating Toilet

Electricity Operated

C B A - C B B C B B C

7. Incinerating Toilet B B A - B B B B B B c

8. Pressurized Tank Toilet A B B - A A A A C B A

9. Packaging Toilet - - - - - - - - -

10. Freezing Toilet - - • - - - - - - -

11. Vacuum Toilet C B A - C C B B c C c

12. Suds Operated Toilet - B A - - - c C c

13. Macerator Toilet A B A - B A A A B A c

14. Dual Flush Toilets A B B - A A A B c B c

15. Wash-Down European Toilet A B B - A A A A A A c

16. Grey Water System for

Toilet Reuse

C B C - B A B B C A c

17. Total Wastewater Systems,

Toilet Reuse

C B A - B B B A B B B

18. Total Wastewater Systems,

Total Reuse

C A A A B B B B C C c

19. Aerobic Units B C C C B B B B A A A

20. Evapotranspiration Beds B C A A B B B B B C B 21. Mounds B C A A B B A A B C A

22. Spray Irrigation A B A A B B B B B A B 23. Greywater Disposal by

Sand Filtration

A C C A A B B A B B B

35
Table 5

Site Conditions Appropriate to the Onsite Wastewater Devices

SYSTEM

SITE CONDITIONS FOR WHICH SYSTEM

MAY BE CONSIDERED APPROPRIATE

1. Compost Toilet - Large Volume

Climate: moderate, warm (cold may be considered)

Home Setting: rural, rural remote

Means of Wastewater Disposal: no means of

disposal

Availability of water resources: water shortage

Home Layout:

Lot Size: small

Lot Topography: steep terrain

Soil Conditions: impervious, over bedrock

Demography:

Population Size: 1 family

Family Size: 1-10

Population Density: sparse

Population Educational Level: high

2. Compost Toilet - Small Volume

i Same conditions as in 1 except:

System restricted to 3 users

3. Oil Flush Toilet Application for Homes: questionable

System is designed for public use (highway

rest areas)

4. Chemical Toilets Application for Homes: questionable

System is designed for mobile homes, and

public facilities. May be used for a temporary arrangement to accomodate 1-4

people.

5. Microphor Toilets Means of Disposal: limited means of disposal

Availability of Water Resources: water shortage

Soil Conditions: slowly permeable soil

36
Table 5 (continued)

SYSTEM

SITE CONDITIONS FOR WHICH SYSTEM

MAY BE CONSIDERED APPROPRIATE

6. Incinerating Toilets - Electricity OperatedHome Setting: rural

Means of Disposal: no disposal, ground water only

Availability of Water Resources: water shortage

Home Layout:

Lot Size: small

Lot Topography: steep

Population Density: sparse

7. Incinerating Toilets - Gas

Same as 6, and may be preferred as its incinerating

efficiency is higher

8. Pressurized Tank

Toilet

May be applied anywhere with the potential of

water saving of 40% of toilet use water

May serve an apartment house

9. Packaging Toilet Information on the systems performance was not

obtained

10. Freezing Toilet The systems serve summer homes in Sweden and

Norway

11. Vacuum Toilets Home Setting: urban

Means of Disposal: limited means of disposal

Availability of Water Resources: Water shortage

Home Layout:

Lot Topography: very steep terrain

Demography:

Population Size: 100-200 families

Population Density: very dense

Population Background:

Note: System may require a high degree of

maintenance

12. Suds Operated

Toilet

Means of Disposal: total disposal

Availability of Water Resources: water shortage

13. Macerator Toilet Means of Disposal: total disposal

Availability of Water Resources: water shortage

37
Table 5 ( continued

)

SYSTEM

SITE CONDITIONS FOR WHICH SYSTEM

MAY BE CONSIDERED APPROPRIATE

14. Recirculating

Toilet

Means of Disposal: grey water only

Availability of Water Resources: water shortage

15. Dual Flush Toilet Potential Water Savings 40% (black water)

16. Wash Down European

Toilet

Potential Water Savings 50% (black water)

17. Grey Water Systems for

Toilet Reuse

Means of Disposal: total disposal

Availability of Water Resources: water shortage

18. Total Waste Water

System for Toilet

Reuse

Means of Disposal: no disposal

Availability of Water Resources: water shortage

Home Layout:

Lot Size: small

Lot Topography: steep terrain

Soil Conditions: impervious over bedrock

Demography:

Population Size: 6-20

Population Density: moderately dense to dense

19. Total Wastewater System

for Total Reuse

Same site conditions as for 18. May be suitable

for very severe water shortage areas.

20. Septic Tank - Mound

System

Home Setting: rural remote to suburban

Degree of Disposal: total disposal

Point of Discharge: ground

Availability of Water Resources: adequate

Home Layout:

Lot Size: moderate

Lot Topography: level to moderately slopy

Soil Conditions: slowly permeable

shallow permeable

permeable with high water

table

38
Table 5 (continued)

SYSTEM

SITE CONDITIONS FOR WHICH SYSTEM

MAY BE CONSIDERED APPROPRIATE

21. Aerobic Tank - Mound

Same as system 20. Aerobic system may be more

efficient in delivering effluent to the mound

of higher quality

Comparison between system 20 and 21 needs further

study

22. Aerobic Tank - E-T BedGeography-Climate: low to moderate precipitation

Means of Disposal: no means of disposal

Availability of Water Resources: moderate

Home Layout:

Lot Size: medium, large

Lot Topography: level ground

Soil Conditions: impervious or when no percolation is mandatory

Demography:

Population Density: sparse to moderately

dense

23. Grey Water Disposal

System by Sand

Filtration and

Disinfection

Used in conjunction with composting toilet

systems where the grey water

39
6 . REQUIREMENTS FOR DEMONSTRATION PROJECTS

The causes of wastewater project shortcomings and failures as discussed in

Appendix D are summarized:

- Insufficient data collection and site evaluation prior to the project

start

.

Improper choice of system.

Small size of sample (for conclusion drawing)

.

Improper system design.

Inadequate maintenance program.

No immediate benefits to the homeowner from the project.

No concern by the homeowner in the project.

Insufficient time allocation for the duration of the project.

Based on these observations the following requirements are recommended for

demonstration projects of innovative wastewater installations.

1 . Establish Specific Objectives to Specific Problems

The demonstration project objectives should be specified in an explicit

manner and call for solutions to specific wastewater problems to specific

site conditions.

2 . Allocation of Time for the Field Work

A minimum of three years is recommended for the field study after installation

work is completed and occupancy usage begun. The time periods at the site

should be divided as follows:

one year of extensive monitoring maintenance and sampling,

two years of observation permitting the users to operate the system in a normal unmonitored manner, according to specifications, while visits and

sampling are only randomly carried out.

3 . Preliminary Effort - Data Collection

Data of performance of conventional systems installed in the same location or

of location of similar conditions should be collected, if not already available, to enable comparison and final assessment of the project.

4 . System Specifications

The project demonstration contractor must provide a comprehensive program plan

to include the following elements:

A. Test Program

1. Criteria for testing and data gathering

2. Criteria for evaluating the quality of wastewater effluents

40
B. Construction

Supervision of system construction

C. Maintenance, Monitoring, Sampling

1. Present a program for maintenance, monitoring and sampling

procedures for the first year of the field demonstration.

2. Present a program for random visits and sampling for the

last two years of the program.

5 . Size of Test Samples (number of homes involved)

The demonstration project should be composed of a sufficiently large sample

size consisting of units of the same type, such that a meaningful statistical

inference can be drawn from the final results.

6 . Appropriate Choice of Home Dwellers

An alternative waste disposal system is generally constructed to meet the

following needs:

From the homeowner's needs: Eliminate nuisance, anguish and expense

From the community's needs: Retain the integrity of the environment,

maintain health and sanitary requirements.

From the legal aspect: Meet code requirements intended to serve both needs.

It is obvious that the three needs are interrelated; however, the individual

homeowner may not have the same perception. An occupant /owner may let a system

fail and dump partially treated wastes into a nearby creek as long as the

house and its immediate environment are not affected. Depending upon the

homeowner's educational background, attitude and personal habits, it will

probably be found that all homeowners are concerned to various degrees with

the first of the above mentioned aspects; fewer numbers of owners/occupants

are concerned with the second aspect; the responsible officials and a very

select few are concerned with the last item. As the success of the demonstration project is very much dependent on the homeowners attitude and cooperation,

it is desirable to have homeowners or occupants of high concern to keep the

system running and guard against any malfunction even when a threat to their

immediate surroundings is not likely to happen. Generally, the site localities

should be where higher educational backgrounds generate interests and motivation;

however, sites with needs for innovative treatments may not always have that

level in the population sample. It may be desirable to establish a policy

whereby the homeowner will contribute some part in financing the capital cost

of the project with later "rewards" as incentives to maintain interests.

From the field inspection trips, it was found that systems built at the

expense of the homeowners worked adequately, while many of the ones provided

at no cost were failing or abandoned.

41
Timetable for Wastewater Disposal System Demonstration

Table 6 outlines a possible schedule of tasks for a demonstration project.

The first 27 months is the period of testing to establish the theoretical

base for the performance of the system, and the last 27 months is the period

of observation at which random visits are made. In the second period, the

most information comes from the user's feedback, where actual field data is

obtained for final evaluation.

42
Proposed

Timetable

for

an

Onsit e

Wastewater

Demonstration

Project

00

CSl c

cc

rvC

in

<T

CNI o cO TO 60 •H O c

*J *4

C >4 44 c TO TO *4 *4

CD *4 E •H 1*4 CL

u E c M *4 o E

TO 03 TO

O TO TO c i—

03 E U* 3 c 03 o *4 TO 3 u O' 0

*4 E 03 (* TO •H TOJ *4 *4 03 *4 a *4 *4 C

TO 03 TO 03 c TO TO >4 E c E TO *4 03 *4 u T3 pH TO 3 *4 oc 03 44 o C TO *4 pH TO c *4 pH

4- TO

C TO3 03 4* *4 44 44 TO c 44 c 1*4 03 C -a 03 3

44 TO <*4 TO 03 TO

C 0 c 44 cr

*J •H 44 44 >

TOJ *4 TO3 *4 V4 *4 U-4 TO *4 C 03 C c 00 0 o -o TO E U 3 3 TO TO c 1*4 1*4 c TO 03 0 C TO 0 c E •H TO TO — T3 TO 3 1 >4 o C a *4 TO TO o. TO C E pH o

o 03 •H •H C o TO TO TO 1*4 03 TO

TO 03 3 TO

U 1* o TO TO 0 *4 44

U

u *-> *4 O" *4 TO TO •H E >> <*4 TO 03C

W

TO TO 1* TO 1 *4 *4 *4 TO 1 TO 1 >4 TO c

X) •o TO

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43
7. RECOMMENDATIONS

7 .

1

Recommendation of Wastewater Systems for Demonstration

Demonstration projects will consist of systems from the following categories:

- Systems whose performance adequacy has been proven with reasonable

certainty, in which case reaffirmation of their capabilities and worth

is the major objective of the project.

- Innovative systems of incomplete field experience where testing their

capabilities and limitations is the major objective.

In either case, redundant backup features will be required, and in some cases,

provisions for "hook-up" to a conventional system are desirable should

failure take place.

7.1.1 Systems Recommended for Demonstration

7. 1.1.1 Low Flush Toilets for Water Conservation and Wastewater Reduction

o European Flushdown Toilets

Provides a 40 percent reduction of the total household toilet flush

water with no anticipated problems except for a slightly large need for

cleaning the toilet surfaces.

o Two-Step Flush Toilet Mechanisms for Ordinary Toilets

Provides a 40 percent reduction of the total household toilet flush

water

.

o Pressurized Tank Toilets

Several designs are available for water reduction in the range of 50-80

percent as compared to the water consumption of the "water saver" (3 1/2

gal. syphonic toilet), which provides for a 30 percent saving relative

to the five-gallon toilet.

o The Microphor Toilet

Provides a 90 percent reduction as compared to the five gallon toilet

water usage.

Limitations: Economic constraints, i.e., capital costs of compressor and

parts plus some maintenance and power costs. The toilet operates with

moving mechanical components which generally is an undesirable feature in

principle for water closets. This toilet has been approved by the major

model codes and has started gaining acceptance.

44
The Composting Toilet of the Large Type

The system is reasonably well suited for the following home settings:

Rural to remotely rural settings

Sparcely populated areas where no advantage can be attained by

community type wastewater systems

Areas of no means of wastewater disposal

Large families (compost tank can be enlarged)

Limited water resources

System Limitations:

Problems of users' acceptance. The users must be informed of the systems

workings and given instructions for operation of the systems.

- Maintenance

Special consideration for the home design

May be undesirable for installation in cold climate regions

7. 1.1. 2 Wastewater Systems

R.ecirculating Grey Water Systems for Toilet Flush Water Reuse

These systems are very simply constructed, do not require sophisticated

components and can be maintained by the homeowner or an ordinary plumber.

System acceptance should not pose a problem except for the formation of high

levels of turbidity in the recycled grey water in the toilet bowl. The

system can be accomodated in any setting where water conservation and/or a reduction in the total wastewater is required.

The system is suitable for serving an individual home. Appreciable reduction

in cost may be attained when used in apartment houses to serve several families,

with a common treatment and recirculation system.

Recirculation of Total Wastewater for Toilet Flush Water Reuse

The "Cycolet" - Thetford Corporation

At present, this system is primarily designed to meet needs of public

facilities where water shortage exists, and the land is unsuitable for soil

absorption systems, or the local real estate cost is high for allocating land

for wastewater treatment and disposal. These systems are relatively costly

and not suited or designed for individual homes. This system may be appropriate to serve an apartment house of five or more families in an urban and

suburban setting.

45
Septic Tank - E-T Systems

This system is suitable for rural and suburban settings in the south western

states and any region of dry climate and low precipitation. Its applicability

to the eastern states is questionable. Redundant features should include

standby beds to be used in case severe climatic conditions such as high

precipitation and/or unusually long freezing periods which may cause system

loading values to fall outside the design criteria. The beds should be serially

designed to constitute several E-T compartments so that the systems downstream

are being used only when the upstream systems have been loaded to their full

capacity. Such a design will facilitate obtaining data on critical values and

minimum area requirements for sizing E-T beds. Water conservation applicances

and fixtures such as low flush toilets and low flow shower heads are highly

desirable as they may result in an appreciable reduction in the total E-T bed

size.

Septic Tank - Mounds Systems

Septic tank - mounds systems are presented with a greater degree of confidence'

than E-T systems, as more experience has been gained about them. They are applicable throughout the country and design criteria have been established by

experienced organizations such as the University of Wisconsin and the

North Carolina State University.

7.1.2 Systems of Limited or Questionable Application

Vacuum Toilet System Requires a high degree of maintenance. Noisy

when flushing takes place. Improper cleaning

of the surface of the bowl frequently occurs. With the present design features, the system

applicability for homes is questionable.

Definitely not cost effective for individual

home installation.

Suds Operated Toilet

Macerator Toilets

Small Type Compost

Toilet

The information obtained is not sufficient to

draw conclusions on its applicability. Information

on the Japanese experience is required.

The systems reviewed are designed for recreational

areas and vehicles. With modified toilet design

macerator toilets may be used in homes.

The systems are designed mainly for summer homes.

Systems for year around usage are limited to

three users. They may find application for remote

rural areas with no means of wastewater disposal.

The homeowners must have a positive attitude

towards the systems and willing to take the

appropriate measures for maintenance and operation.

46
7.1.3 Systems Not Recommended for Demonstration

The following systems are not recommended for year around application:

Designed for summer homes and recreational

areas only.

Designed for summer homes and recreational areas.

Designed for summer homes, recreational areas

and vehicles. Limited application for year

around, permanent settings.

Designed for summer homes. High consumers of

energy. May create odors during the time of

incineration. Limited application for year

around homes.

Designed for public usage such as state highway

rest areas. Requires high maintenance and

frequent replacement of parts. Will require

sludge disposal at relatively frequent time

intervals

7 . 2 Recommendation for Research

As earlier mentioned, a great deal of work has been done in all disciplines

related to onsite wastewater systems. The literature, however, has revealed

the following: Conflicting conclusions from seemingly similar projects,

data outputs confined to isolated test cases with no immediate application

for generalization and in turn, information of too general a nature which

cannot be applied to specific cases. Apparently, this is part of the learning

process in light of the nature of onsite systems which may vary from site to

site. A need certainly exists to survey all the innovative systems installed,

define their site conditions in terms of soil evaluation, climatic conditions

and the characteristics of wastewater loadings together with the evaluation

of their performance and economics. This will furnish a broad data base and

onsite wastewater systems. The following topics need further investigation:

1 . Effects of aerobics on soil absorption systems

The effect of aerobic treatment units in comparison to septic tanks has

been a topic of quite a few research programs and demonstrations. It appears,

however, that final conclusions have not been drawn as yet.

A need remains to establish under what conditions are aerobic systems superior

to septic tanks and, in particular when are they economically feasible as applied to tile fields, mounds and E-T beds.

Packaging Toilets

Freezing Toilets

Chemical Toilets

Incinerator Toilets

Oil Flush Toilets

47
2

.

Evapotranspiration Systems

Study under what climatic conditions E-T systems are viable, and the

frequency of the systems failure by ponding when applied in various

climatic conditions. A similar evaluation is required for the relatively

new mechanical rotating disc evaporation system.

3.

Mounds

Similar studies compared to the E-T beds are still required for the mound

systems, in particular, what are the critical underlying clay-soil properties

for which mounds can be expected to perform adequately.

4 . Effect of Electro-Osmosis on Soil Absorption Systems

Electro-Osmosis systems were reported to work well in the west. No information

was seen on their effectiveness in the east; furthermore, recent findings

discredited their merits and effectiveness. Further work is needed for a more

reliable data base.

5 . Combined Black and Grey Wastewater

Comparison of the performance of soil absorption systems of various

compositions subject to application of combined wastewater and grey water.

This topic has been under study by the University of Wisconsin.

6 . Long-term Effects of Grey Water Recirculation for Toilet Flush Water Reuse

Several systems are presently available. These systems use very simple means

of treatment which includes a relatively coarse filter and disinfection by

iodination or chlorination. A study of long-term effects of recirculation is

needed to evaluate the accumulation and the possible increase in concentration

of hazardous treated effluenty residues. Study the degree of the required

disinfection for the prevention of any microbiological hazards from the

production of spray and droplets upon toilet flushing.

7 . Water Exchange in Low Flush Toilets

The revised standard ANSI A 112.19.2-1980 for Vitreous China Plumbing Fixtures

has a new "water exchange" performance criterion that a "dilution ratio of at

least 100 shall be obtained in each initial flush."

No information is available whether this dilution ratio is necessary or sufficient in terms of disease transmission potentials. It is expected that

the "dilution ratio" will be much lower in low flush toilets. A study is

therefore required for establishing the "safe dilution ratio" so that low

flush, water conserving toilets can be evaluated.

48
8 . Wastewater Transport from Low Flush Systems

As water has been the principal transport medium for moving the solid

wastes in the drain lines, low flush toilets may affect the wastewater

transport capabilities of the drainage system. Analytical work is -at present

conducted at the National Bureau of Standards for investigating this problem.

Field work will probably be required for verification of the mathematical

modeling performed at the MBS.

49
Bibliography

1. Microbiology, by Michael J. Pelezar, Jr., Roger D. Reid, E.C.S. Chan,

McGraw-Hill Book Company, 1968 Fourth Edition.

2. Water Reuse Symposium, Proceedings Vol. 1, 2, 3, March 25-30, 1979.

Co-Sponsored by American Water Works Association Research Foundation,

Office of Water Research and Technology (U.S. Department of the

Interior), U.S. Army Medical Research and Development Command,

U.S. Environmental Protection Agency, National Science Foundation,

Water Pollution Control Federation.

9 3. Management of Small Waste Flows, EPA Publication 600/2-78-173, Grant

No. R-302374

.

4. Residential Water Re-Use, by Murray Milne, California Water Resources

Center, University of California/Davis, Report No. 46, September 1979.

5. Home Sewage Treatment, Proceedings of the Second National Home Sewage

Treatment Symposium - 1977, American Society of Agricultural Engineers.

6. Evapotranspiration Method of Wastewater Disposal by Kenneth M. Lomex

and Paul N. Winn, Horn Point Environmental Laboratories, Center for

Environmental and Estuarine Studies, University of Maryland.

7. Manual of Grey Water Treatment Practice, by John H. Timothy Winneberger,

Published by Ann Arbor Science Publishers, Inc., 1974.

8. Segregation and Separate Treatment of Black and Grey Household Wastewaters to Facilitate Onsite Surface Disposal, by Robert Sregrist, Small

Scale Waste Management Project, University of Wisconsin.

9. A Study of Methods of Preventing Failure of Septic Tank Percolation

Systems, by P. H. McGauhey and J. H. Winneberger, Sanitary Engineering

Research Laboratory, College of Engineering and School of Public Health,

University of California, Berkeley, October 31, 1965, Serial Report No.

65-17.

10. A Study of the Biological Aspects of Failure of Septic Tank Percolation

Fields, by P. H. McGauhey, G. T. Orlob, J. H. Winnenberger , Sanitary

Engineering Research Laboratory, University of California, Berkeley.

11. Alternatives to Septic System Home Wastewater Disposal in Northwest

Arkansas, by Cheryl L. Peterson, Arkansas Water Resources Center, Thesis

and Dissirtation Series, Report No. 7, University of Arkansas, 1977.

50
12. A Study of Flow Reduction and Treatment of Waste Water From Households,

by James R. Baily, Richard J. Benoit, John L. Dodson, James M. Ilobb

,

Herold Wallman, Prepared for Federal Water Quality Administration,

Department of the Interior, Program #11050 FKE, December 1969.

13. Individual Onsite Wastewater Systems, Proceedings of NSF National

Conferences, 1974-1978, Edited by Nina McClelland, Ann Arbor Science,

Ann Arbor, Michigan.

14. The Effect of Aerobic and Anaerobic Household Sewage Pre-treatment on Seepage Beds, by R. Laak, 1966, University of Toronto, Department of

Civil Engineering.

15. Standard Methods for the Examination of Water and Wastewater, 1975,

14th Edition. Published by American Public Health Association,

Washington, D.C.

16. Study of Water Recovery and Solid Waste Processing for Aerospace and

Domestic Applications, Prepared under Contract NAS9-12503, National

Aeronautics and Space Administration, Houston, Texas. Grumman Aerospace

Corporation, Bethpage, New York, Dec. 1972.

17. Clogging and Unclogging of Septic Systems Seepage Beds, by J. M. Harkin,

M.D. Jawson, Soil Sciences Department, University of Wisconsin.

18. Use of Physical Methods to Expand Soil Survey Interpretations of Soil

Drainage Conditions by J. Bauman, Soil Science Society of America,

Volume 37, No. 3, May-June 1973.

19. The Economics of Urban Sewage Disposal by Paul B. Downing,

Fredrick A. Praeger, Publishers, New York - Washington - London.

20. Sewage Disposal by Evaporation - Transpiration by Edwin R. Bennet

,

et al, Colorado University, Boulder, September 1978, EPA/600/2-78/163

21. Pilot Plant Study Nitrogen Removal in a Modified Residential Subsurface

Sewage Disposal System, Suffolk County Department of Health Services and

William F. Cosolich Associates, P. C. Hauppauge, New York, Oct. 1977.

22. Sewer Moratoria Causes Effects Alternatives. The Department of Housing

and Urban Development - July 1977.

23. Treatment and Disposal Alternatives for Domestic Sewage Management.

The Department of Housing and Urban Development - April 1977.

51
24 . Household Wastewater Composition and Properties by: Lars Karlgren,

Krister Ljungstom, Eskil Olsson, Viktor Tullander Bulletin M77 :16E,

The National Swedish Institute for Building Research, 1979.

25. Recycled - Water Sanitary Waste Disposal System by: William Joseph Shoupp.

Dissertation submitted to the Graduate School of West Virginia University,

Morgantown, West Virginia, 1978.

26. Household Energy Conservation Study. Final Report, April 1978.

G.E. Report No. 78SDS 4219. General Electric, Valley Forge Space

Center. P.0. Box 8555, Philadelphia, Pennsylvania 19101.

27. Appropriate Sanitation Alternatives - A Field Manual, Energy, Water

and Telecommunications Department. The World Bank, October 1978.

28. Demonstration of Non-Aqueous Sewage Disposal System, Environmental

Protection Agency Series EPA-670/2-73-088 , Dec. 1973.

29. Final Environmental Impact Statement (EIS) on Mound System for Private

Waste Disposal, October 1979, The State of Wisconsin.

52
References

1. Electro-osmosis, A Proven Soil Absorption Sewage System, Environmental

Consulting Associates, 5522 Atlas Street, Los Angeles, California.

2. NSF - National Sanitation Foundation, STANDARD 40, Individual Aerobic

Wastewater Treatment Plants.

3. NSF - National Sanitation Foundation, STANDARD 41, Wastewater Recycle/

Reuse and Water Conservation Systems.

4. Dindal, Daniel L., Soil Organisms and Stabilizing Wastes, SUNY College

of Environmental Science and Forestry, Composting and Recycling

Conference, July/August 1978.

5. Nichols, H. Wayne, Analysis of Bacterial Population in the Final Product

of the Clivus Multrum, Center for the Biology of Natural Systems,

Washington University, St. Louis, Missouri.

6. Ilberg, H. and Zanker, K. J. , Water Conservation Measures in Plumbing

Vacuum Sewage System - Israeli Experience, the Standards Institution of

Israel, Sponsored by the U.S. National Bureau of Standards, Contract

No. NBS (G)-IOO-IS-ST-TBT, December 1973.

i 7. Report on the Preliminary Economic Study of Vacuum Sewage Scheme at

Yellow Elder Gardens and Big Pond Nassau, Bahamas, December 1978. By

D. Tilakaratue, Water & Sewerage Corporation.

8. Bernhart, Alfred P., Treatment and Disposal of Waste Water from Homes

by Soil Infiltration and Evapo transpiration. University of Toronto

Press, 1973.

9. Tanner, C.B. and Bouma, J. , Influence of Climate on Subsurface Disposal

of Sewage Effluent, College of Agriculture and Life Sciences, University

of Wisconsin, Madison, Wisconsin.

10. Hoover, M.T., G.W. Peterson and D. D. Fritton, Utilization of Mound

Systems for Sewage Disposal in Pennsylvania Department of Agronomy,

The Pennsylvania State University.

11. Pasrew, Lee, Evapotranspiration as an Alternative to Septic Systems in

Rural Metropolitan Washington, Division of Planning, Office of Community

Development, Montgomery County, Maryland, March 1979.

12. Waldorf, Larry, Rural Sanitation, The Appalachian Regional Commission,

Washington, D.C.

13. Glasser, Merril B. , Garrett County Home Aeration WTastewater Treatment

Project, 1973-74, Environmental Health Administration, Bureau of Sanitary

Engineering, Maryland State Department of Health and Mental Hygiene.

14. Rex, Connie C. , Consumer Acceptance of Water Recycling, Marketing Research

Department, Pure Cycle Corporation, Boulder, Colorado, September 1977.

53
15. Stone, Ralph and Company, Inc., Wastewater Reclamation, Socio-Economic,

Technology and Public Acceptance, Distributed by NTIS, U.S. Department

of Commerce, May 1974.

16. On-Site Wastewater Treatment Alternatives (Notes for a 2-day seminar

from Jan. 15, 1980) by Applied Science Through Research and Engineering,

Charlottesville, Virginia.

17. State of Maine - Plumbing Code, Subsurface Wastewater Disposal Regulations,

Department of Human Services, Division of Health Engineering.

18. Rural Wastewater Disposal Alternatives, State Water Resources Control

Board, State of California Office of Planning and Research, Interagency

Agreement W6-028-40, September 1977.

19. Evaluation of Microbiology Standards for Drinking Water, EPA/570/9-78-00c

,

1978.

20. Wellings, Flora Mae; Lewis, Arthur L. ; Mountain, Carrol W. ; and

Pierce, Virginia, Demonstration of Virus in Groundwater After Effluent

Discharge into Soil, Epidemology Research Center, Tampa, Florida.

21. Gerba, Charles P.; Wallis, Craig; and Melnick, Joseph L. , Microbiological

Hazards of Household Toilets: Droplet Production and the Fate of Residual

Organisms, Department of Virology and Epidemology, Baylor College of

Medicine, Houston, Texas. American Society for Microbiology - Applied

Microbiology Journal, March 1975.

22. Cliver, Dean 0., Infection with Minimal Quantities of Pathogens from

Wastewater Aerosols, Proceedings of Symposium on Wastewater Aerosols and

Diseases, September 19-21, 1979, EPA Sponsorship.

23. Fancy, John, Individual Aerobic Plant Operation and Maintenance, P.0

Box F, Waldboro, Maine.

24. Siegrist, Robert L., Segregation and Separate Treatment of Black and

Grey Household Wastewaters to Facilitate Onsite Surface Disposal, Small

Scale Waste Management Project, University of Wisconsin - Madison,

College of Agriculture and Life Sciences.

25. Siegrist, Robert L. , Management of Grey Water (See Ref. 24).

26. Winter, Fred, "Field Trip Reports" from the Project "Sewerless Devices

Evaluation Basis", the National Bureau of Standards. Letter Report to

the Department of Housing and Urban Development, Division of Energy,

Building Technology and Standards, June 20, 1980.

54
APPENDIX

55
A. Compilation of Onsite Wastewater Elements and Systems Reviewed

Table 7 contains the list of the systems reviewed, their manufacturers

name and reference to the field trips for which these systems were visited.

TABLE 7

Wastewater Devices Observed or Reviewed in the Project

Observed Reference

Item System Manufacturer (number) to Trip No.

Waterless Toilets

1 Composting Toilets Clivus Mult rum over 5 5, 11, 12,

Large Volume Type

Toa Throne

15, 20

Carousel *

2 Composting Toilets Mulbank over 5 13, 14, 15

Small Volume Type

Humus 1 24

3 Oil Flush Toilets Monogram Industries 2 9, 15

4 Chemical Toilets Western Field 1 13

(nearly waterless)

Jensen

Monogram Industries 1 20

5 Incinerator Toilets

Gas Fired

Incinolet 2 15

6 Incinerator Toilets Incinomod 2 15

7 Packaging Toilets Factosm, Sweden

8 Freezing Toilets Osby, Norway

9 Suds Toilets

(nearly waterless)

Nepon, Japan *

56
Table 7, continued

Low Flush Toilets

10 Vacuum Toilets and

Draina ge

Colt Industries

Mansfield

2 2

11 The Microphor Microphor Inc. 3 7

12 Macerator Toilet Monogram Industries *

13 Pressure Tank,

Toilet

"Flushmale, Water

Control Products

1 7, 14

Int. Water Saver,

Canada

*

14 European Flush

Toilets

Manufacturer

Throughout Europe

15 Two-Step Flush

W.C. Mechanisms

**

Aerobic Treatment Systems -

16 Aeration-Flow Through Bi-A-Robi 3 1. 15

17 Aeration-Batch Type Chromaglass

Jet Aeration

Eastern Environmental

Control

20

systems

were observed

1, 4, 6,

13, 15,

20, 25

18 Rotor Disc System CMS Equipment,

Canada

* Systems seen in exhibits.

** Two-step flush mechanisms are at present tested and evaluated at the

National Bureau of Standards.

57
Table 7, continued

Soil Absorption Systems

19 Multiple Alternating

Leach Field —

20 Electro Osmosis —

21 Evapo transpiration — over 5 1, 6, 9,

Beds 20, 25

22 Mounds — over 5 4, 10, 20,

24, 25

23 Sand Filters — over 5 10, 13, 15

Wastewater Reuse Package Plants

24 Blackwater - Ecol-Sanitary

,

Recirculating Toilet Canada

25 Grey Water Water Cyk 1 22

Recirculation

for Toilet Reuse

Aqua Saver 1 23

26 Total Wastewater Pure Cycle 1 16

Treatment and

Recirculation for

Toilet Reuse

Corporation

27 Total Wastewater

Treatment to Potable

Water Quality

Pure Cycle 1 19

28 Lagoons — 2 17, 20

29 Spray Irrigation — 1 10

30 Rotating Discs - Evaporation

58
B . Summary of the Field Trips Conducted

The following are summaries of the twenty five field trip reports written of

trips to onsite conducted in the course of this study. (See Preference 26) .

Field Trip No. 1

Date of Visit: March 5, 1979

Location Sites: Catlellsburg , Boyd County, Kentucky

Persons Contacted: Mr. David Salisbury - FIVCO (606) 739-5191

Referred by Mr. Larry Waldorf from the Appalacian

Regional Commission in Washington, D.C.

Systems: Aerobic Wastewater Units - Boyd County Demonstration Project

This setting encompasses 36 dwelling units in a rural community. The waste

disposal systems include aerobic units from six manufacturers with various

configurations of wastewater disposal such as E-T bed, direct stream

discharge and recirculation, and reuse for toilet flush water.

Systems Performance as Observed and as Described by the Users

The individual systems are rated from satisfactory to failure:

Wastewater recirculation system: The system operates well and solves

the problem of water shortage experienced by the homeowner.

- Aerobic Units: Malfunctioning of the aerobic unit pumps.

E-T bed: Failure of the bed resulting in flooding.

General problem: Lack of systems maintenance.

Field Trip No . 2

Date of Visit: March 9, 1979

Location of Site: White Flint Shopping Center, Rockville, Maryland

Person Contacted: Mr. George Pontias, Maintenance Supervisor

(301) 881-1780

System: Black Water Waste Disposal Vacuum Drainage

The system is connected to 150 toilets via two and four inch PVC pipe lines.

The wastewater goes to two 2,000 gallon storage tanks. Vacuum pumps keeps the

vacuum in a range of 18" Kg (shutoff) to 10" (restart) vacuum. Wastes are evacuated directly to a sewer line with no prior treatment.

Water consumption per flush: 1 liter (quart)

Manufacturer: Colt Industries

59
Problems

- Pipe lines get clogged but only with the use of paper towels, handy-wipes

and similar heavy paper material.

- Some problems in loss of vacuum (but not significant)

.

- Some problems in flushing mechanisms - needle valve has to be reset to

obtain the 1 pint flush.

Normally, these problems are manageable and the system works well except

for inherent problems with the present system design resulting in a high

noise level upon flushing the toilet and occasional incomplete cleansing

of the toilet bowl. f

Field Trip No. 3

Date of Visit: March 13, 1979

Location Site: Montgomery County, Maryland

Person Contacted: Mr. Wallace from Montgomery County

Department of Environmental Protection

Construction of Wells & Septic Tanks - (301) 468-4192

Purpose of Visit: Study soil evaluation procedures for the

approval of construction of septic tanks.

Soil evaluation in the county is performed by the "soil percolation test."

Soil Percolation Test Criterion: A minimum of 1 inch per 30 minutes.

Limitations of the validity and reliability of this test were realized. As

observed, "perc test" results in one property varied from 1/8" to 7" per

30 minutes.

Field Trip No. 4

Date of Visit: March 16, 1979

Location of Sites: Montgomery County

Person Contacted: Mr. Lyman Schooley from Montgomery County EPA - (301) 468-4126

Systems : Aerobic Units and Mounds

The three systems visited are composed of aerobic units of the "batch type" and

mounds. The units worked adequately, with the aerators diffusing air into the

effluents. From the three mounds observed, one was not working properly, as seen by the soggy ground around it.

Apparent reasons for its failure: Improper construction practices and lack of

proper maintenance of the mound crown.

60
Field Trip No. 5

Date of Visit: March 21, 1979

Location Site: Industrial Building in Washington, D.C.

Person Contacted: Mr. Frank Reeves, R. M. Thornton, Inc.

(301) 350-5000

System: Large Volume Composting Toilet and Grey Water System

The systems have been in operation for 20 months and serve the office staff.

The grey water system is composed of a roughing pea gravel filter and the

treated grey water are used for gardening. No complaints were expressed by

the users.

Field Trip No. 6

Date of Visit: April 4, 1979

Location Sites: Montgomery & Fairfax Counties

Person Contacted: Mr. Curtis Bohlan from the Eastern Environmental

Controls (301) 778-0967

Systems : Aerobic Units and E-T Beds

Three systems were observed. The units are of the batch type and worked well.

A minor malfunction occurred in one unit. A five hour power failure caused a five hour time lag in the aerator’s operating cycle. The cycle control was

reset and the system was restored to normal operating conditions. The beds

were dry and seem to function well.

Field Trip No . 7

Date of Visit: April 11, 1979

Location Site: Kent Island, Queen Ann County, Pier No. 1 Motel

Person Contacted: Mr. Morris, Motel owner (301) 643-5011

Systems : Pressurized Tank Toilets and the Microphor Toilet

Twenty-two toilets are installed in the motel bathrooms. The toilets operate

on a pressure of 40-55 psi and require 2 gallons per flush. No complaints

were expressed from the motel owner. One Microphor toilet is installed for

observation only and is very rarely used. Some malfunction was observed in

this toilet performance which manifested itself by water splashing out because

of improper watertightness of the flapper valve.

61
Field Trip No. 8

Date of Visit: April 20, 1979

Location Sites: Rest Areas on US 64 in the vicinity of Charlottesville,

Virginia

Person Contacted: Mr. J. Tailor from the Virginia Highway Department

(804) 786-2859

Systems : Oil Flush Toilet System

Extended Aeration with Water Reuse for Toilet Flushing

The oil flush toilet system serves fifteen toilets in the rest area. The

system has been in operation for three months. Complaints were expressed by

the rest area attendants regarding leakage of mineral oil. An appreciable

amount of oil is drained with the wastes during disposal and in the time of

the replacement of the filter. Complaints were expressed on poor performance

of the incinerator resulting in incomplete incineration and in its excessive

energy consumption of fuel oil.

The extended aeration system has been successful, trouble-free and cost

effective, delivering a high degree of effluent quality and retrieving most

of the wastewater (95 percent) for toilet flush water reuse.

Field Trip No. 9

Date of Visit: May 21, 1979

Place of Visit: State Highway 70 in Craven County, North Carolina

Wastewater System in a rest area. Persons Contacted: Mr. Bill Johnson and Jim Armstrong from the

Highway Department (919) 733-2920

System: Oil Flush Toilet System and Grey Water E-T System

The oil flush toilet system serves nine toilets and three urinals. The

system has been recently constructed and no working experience has been

obtained. A recent inquiry indicated that in the first year of usage of

the system, mechanical problems occurred causing offensive odors from the

toilets

.

62
Field Trip No. 10

Date of Visit: May 22, 23, 1979

Place of Visit: North Carolina State University and Waste Disposal

Systems in the vicinity of Raleigh, North Carolina

Person Contacted: Robert Rubin, from the Biological & Agricultural

Engineering (919) 737-2675

Purpose of Visit: To learn about the activities of North Carolina State

University in onsite waste disposal systems and take

part in a field tour.

Systems Observed:

Sand filters, recirculating sand filter, spray irrigation system, pressurized

mounds and aerobic unit. The aerobic system seemed to be failing. The

aeration pump was not in operation and the dark untreated sewage was observed

in the aerator tank.

Field Trip No. 11

Date of Visit: June 27, 1979

Location: Sperryville, Virginia

Person Contacted: Mr. Stanley Thompson (703) 987-8714

System: Large Volume Composting Toilet

The system serves a family of three. The compost tank is connected to two

toilets placed in two levels in the house. The system has been used for

eighteen months to the full satisfaction of the homeowner.

Field Trip No. 12

Date of Visit: July 2, 1979

Location: Office building in Washington, D.C.

Person Contacted: Mr. Fox, Institute of Local Self Reliance - 232-4108

System: Large Volume Compost Toilet

The system was installed for demonstrating the feasibility of waterless

toilets, and has been in operation for two and one-half years. The office

has a staff of 15 but only 10 persons use the compost toilet (the rest prefer

to use the conventional facilities). The system has been working well.

63
Field Trip No. 13

Date of Visit: July 18, 1979

Location Sites: Garrett County, Maryland

Persons Contacted: Merril B. Glasser - Environmental Health Administration,

State of Maryland (301) 334-3965

Edgar Harman - Oakland Department of Health

(301) 334-8111

Systems : Aerobic Units , Sand Filter Beds , Chemical Toilet , Small Type

Compost Toilets

Aerobic Units : The systems were installed as part of a demonstration project

in 1973 and were under observation for a one-year period. Of the three sites

visited, two systems were abandoned, one of which delivers raw effluent to a nearby ditch. The third was not in operation at the time of the visit

(apparently for saving of electricity) but was reactivated to proceed normal

operation.

Sand Filter Beds : The beds serve private homes and were designed by the

county. The clear odorless effluent flows to a nearby creek. The beds

function adequately.

• Chemical Toilet : Used by a single person in a home having no plumbing

facilities and provided a solution of water conservation and wastewater

disposal

.

Small Type Compost Toilets : Two homes were visited. In one home, the toilet serves two persons and works well. In the other, the toilet has been failing:

creating offensive odors, accumulating liquids and attracting flies. Reasons

for failure: Improper vent design, possible system overloading from the family

of four and incorrect seeding of organic material into the wastes, for maintaining the proper carbon to nitrogen ratio.

Field Trip No. 14

Date of Visit: July 24, 1979

Location of Site: New Hampshire

Person Contacted: Mr. Gunnar Baldwin, Thorton Gore Enterprises, Inc.

(603) 726-3295

Systems : Small Type Compost Toilets , The Microphor

Small Type Compost Toilets: The toilets were observed in three homes. The

homeowners expressed satisfaction with them. Some problems occur in time of

large social gatherings as these systems are designed for, at most, three

persons

.

Microphor Toilets : The toilets were observed in a private home and in a restaurant. The system performed adequately.

64
Field Trip No. 15

Date of Visit: July 25 and 26, 1979

Location of Site: Augusta, Maine and Vicinity

Person Contacted: Mr. Eugene Moreau, Dept, of Human Services, Augusta, Maine

(207) 289-3826

Systems : Composting Toilets - Large and Small Type , Oil Flush Toilets , Incinerator Toilets - Gas and Electric , Grey Water Disposal Systems , Aerobic Systems , Sand Filters

Compost Toilets of the Large Type : Several systems were observed in year

around settings, summer homes, restaurants and schools. All worked well except

for the one in the school which failed apparently because of excessive usage

and lack of adequate maintenance.

Compost Toilets of the Small Type : Observed in summer homes and a high school

dormitory. The toilets installed in the dormitory for the male students were

failing, manifested by a high accumulation of solid wastes in the toilets and

liquids in the disposal trays.

Oil Flush Toilets : Observed in a state highway rest area. The toilets are manufactured by Monogram Industries. No serious problems were reported by the

facility attendants.

Incinerator Toilets - Gas Operated : Observed in two homes. No complaints

were expressed by the owners.

Incinerator Toilets - Electricity Operated : Observed in two public places.

The one installed in a court house had been abandoned because of offensive

odors to the neighbors in the time of incineration. The other, installed in

a library, has limited usage to the library staff only.

Grey Water Disposal System : Used in homes where compost toilets handle the

black water wastes. The grey water is filtered, disinfected by U/V or chlorination and then discharged to the ocean.

Aerobic Systems : Observed in several installations. No problems reported.

Sand Filters : Observed in several installations. Some serve large systems,

such as restaurants in the waterfront. No problems reported.

Field Trip No. 16

Location: Ann Arbor, Michigan

Date of Visit: November 1, 1979

Person Contacted: William Bullard - Thetford Corporation

(313) 769-6000

65
System: "Cycolet" Wastewater Package

This package contains hardware for wastewater recirculation and reuse for

toilet flush water. The trip included a visit to the company’s manufacturing

facilities and observation of a system in normal usage.

Field Trip No . 17

Location: Michigan, Monroe County and Vicinity

Date of Visit: November 2, 1979

Person Contacted: Jay Bastion from the Department of Transportation

Systems : Oil Flush Toilets , Septic Tank Lagoon System

These systems serve state highway rest areas.

Oil Flush Toilets: The following problems were reported by the station's

attendants: Dirty surfaces remain after flushing, malfunction of the

macerator pump, corrosion of copper tubes and malfunction of the controls

in the holding tank.

Field Trip No. 18

Location: The University of Wisconsin, Madison, Wisconsin

Dates of Visit: November 5 and 6, 1979

Person Contacted: Jerry Tyler (608) 263-3137

The purpose of this trip was to see the ongoing research programs of the

university in onsite systems. The University has been very active in this

in particular, in the topics of grey water studies and soil absorption

wastewater systems, with emphasis in finding optimal solutions for wastewater dosage into the soil absorption beds.

Field Trip No. 19

Location: "Pure Cycle," Boulder, Colorado

Date of Visit: November 7, 1979

Person Contacted: Robert 0. Menkes (303) 449-6530

System: "Pure Cycle" Wastewater Package

"Pure Cycle" is a package for wastewater recirculation and reuse for drinking.

The trip included a visit to the manufacturing facilities and to a home where

one system is being used (no information was obtained from the users)

.

66
Field Trip No. 20

Location: Boulder County, Colorado

Date of Visit: November 8, 1979

Person Contacted: Mike Whitemore from Boulder County Department of

Health (608) 441-3530

Systems : Compost Toilets - Large Type , Chemical Toilet , Septic

Tank - Mound System , Septic Tank - E-T Bed , Aeration Unit - Lagoon System

Compost Toilets : The problems experienced with the toilet observed were the

hardening of the waste pile in the compost tank and excessive accumulation

of liquids. The reasons to this failure were attributed to improper venting

of the system.

Recirculating Chemical Toilets: Situated in a small diner which also was used as a home. The owners experienced unpleasant odors and breakage of

parts, apparently because of excessive usage.

Septic tank - E-T Beds : Several systems were observed. All perform well.

Aeration Unit - Lagoon System : One system was visited. The system worked

adequately.

Field Trip No. 21

Date of Visit: November 30, 1979

Location of Site: Upper Occoquan - Northern Virginia

Person Contacted: Mr. Ehalt - (703) 830-2200

System: 15 MGD Advanced Wastewater Plant

The purpose of the trip was to review the elements of an advanced large

wastewater system. This plant serves a population of 70,000 in Northern

Virginia. The system was designed to meet the problem of increased discharges

of conventionally treated effluents to the Occoquan Watershed in Virginia.

The system delivers a very high quality effluent, of nearly potable water

quality to the watershed. The solid wastes products are being handled by

composting.

Field Trip No. 22

Date of Visit: December 19, 1979

Location of Site: Washington, D.C.

Person Contacted: Mr. Bowl, Eaton Water Cyk (301) 821-8892

67
System: Grey Water Recycle System for Toilet Flush Water Reuse

The system is installed in a house and is under study by Dr. Foresti from

the Catholic University. The installation is composed of a grey water

collection network, holding tank, and filters. Prior to recirculation,

the effluents are disinfected by iodination. The system appears to function

well except for noticeable turbidity of the water in the toilet bowl.

Field Trip No. 23

Date of Visit: January 16, 1980

Location of Site: Queen Ann County, Maryland

Person Contacted: Dick McCulloh, "Aqua Saver" - (301) 644-9550

System: Grey Water Recycle for Toilet Flush Mater Reuse

This installation is similar to the one described in Field Trip No. 22,

except that disinfection of the recirculated wastewater is done by chlorination. The system was installed in a home after approval was granted by

the county and constructed to reduce the total wastewater flow to the

septic tank. The homeowner experienced no problems during its three months

of operation and the turbidity appearing in the bowl is not troublesome for

him.

Field Trip No. 24

Date of Visit: January 23, 1980

Location of Sites: Gettysburg, Pennsylvania and Vicinity

Person Contacted: Mr. William Kill from V.S.P., Valley Septic Products

(717) 334-9135

Systems : Small Community Wastewater Systems, Compost Toilet - Small Type

Small Community Wastewater System : The system serves nine families and is

composed of two large capacity batch type aerobic units and a large mound.

At the time of the visit, the aerators were not operating due to malfunctions

of the relays and dark scum showed in the tanks. (The system is fairly new

and does not work to its full capacity as yet)

.

Compost Toilet: The system is installed in a grocery store and serves three people, generally with no problems. In the past, the fan broke which

created a very unpleasant odor. The fan was immediately replaced and the

odor was eliminated.

68
Field Trip No. 25

Date of Visit: March 17, 1980

Location of Sites: Montgomery County

Person Contacted: Lyman Schooley from Montgomery County EPA

Systems : Mounds and E-T Beds - Montgomery County Demonstration Project

Five systems with combinations of septic tanks, aerobic units and E-T

beds were installed in 1977 and monitored for a one year period. At the

time of the visit, all the systems exhibited some form of failure from

ponding of a clear effluent to flooding of dark raw sewage with unpleasant

odor. Of the mounds visited in this trip, some worked well and some exhibited surface ponding around their base.
c. Discussion of Wastewater Systems as Viewed from the Field Trips

As mentioned earlier, the activity of the field trips illuminated the

aspects involved in onsite innovative wastewater systems, in spite of the

small sample size inspected and reviewed. The conclusions drawn on the

systems performance are based upon visual inspection, information from the

home occupants, and discussions with the engineers, manufacturers and

State Health representatives who accompanied the investigator on the trips.

Table 9 lists systems failures or malfunctioning as observed on the trips.

The following discussion is based on the field trip observations and the

literature.

C . 1 Composting Toilets

Composting toilets have been a topic of controversy for quite some time

because of their unique mode of operation and various problems involved.

Theoretically, compost toilets form a well balanced, naturally managed

ecosystem composed of communities of microorganisms which inhabit the

wastes, creating a food web where one colony thrives on the other and

finally transform the wastes into a stabilized odorless organic matter and

soil humus [4]. Also, test results [5] from laboratories indicate that

the end product is harmless and consists of soil borne organisms which are found in any ordinary soil. Compost toilets require certain conditions such

as proper air, and temperature, moisture and a fixed carbon to nitrogen

ratio, otherwise, they may fail. Needless to say, failure of a composting

toilet is a very unpleasant experience. Another inherent limitation's the

fact that one cannot take the system for granted with no maintenance and

as one user expressed it "you have to build your house around them."

Since people's life-style and personal habits vary, the composition of the

waste products vary from household to household and consequently uniform

maintenance policies cannot be prescribed.

Each individual has to experiment with the system and discover from his

experience, the optimal procedures for running the compost toilet. The

toilets certainly have an "odd shape" similar to an outhouse toilet and to some people their appearance may not be appealing. Some systems had a "slightly musty odor," which was, however, bearable and caused no alarm.

The breaking in period is another aspect to take into consideration. It

generally takes one year for the system to reach normal operating conditions.

In that period, one may experience accumulation of liquids in the tank, odor

and flies.

Of course, the problem of acceptance is the most critical aspect. Of interest

was an installation in Washington, D.C. The "large type" compost toilet is

installed in the Institute of Local Self Reliance. This organization is in

the energy conservation business. One may expect the employees of such an organization to welcome the system and use it with no reservations. However,

out of fifteen staff personnel, six preferred to use conventional facilites.

70
In the course of the trips, successes and failures were witnessed. The

failures are described in Table 9. Due to their large composting chamber,

the "large volume" type composting toilets are more stable, less susceptible

to variations in wastes loadings and the mode of failure less critical as compared to the small systems. Failure of composting toilets is manifested

by intolerable odors, flies and accumulation of liquids in the tray compartment at the bottom. The reasons for failure were attributed to improper

venting and overloading. This system cannot accommodate more than three

persons. Of interest was a phenomenon observed in year-round dormitory for

boys and girls of high school age. There were two small type composting

toilets in the girl's bathroom which worked reasonably well while in the

boy’s bathroom failures took place. This also repeated itself when the

facility usage was switched, namely, the girl's had no problem and the boy's

toilets failed. The differences in toilet habits between the sexes, in

particular, the differences in use of toilet paper probably accounted for

the difference of performance, as the additional paper normally used by the

female students sustained a more appropriate carbon to nitrogen ratio.

Composting toilets may work well provided the proper operating conditions are met with proper attention given to them. They may be suitable for individual

homes in rural settings, and in areas of limited water resources.

Their merits: They are completely waterless, have very little operating

expenses, and can be maintained by the homeowner.

Their disadvantages: May require a change in life-style and acceptance;

susceptible to failure if proper maintenance is not carried out.

C.2 Chemical Toilets

Chemical toilets are designed for recreation vehicles and situations of

occasional use. They are generally not intended to be used in houses on a year-round basis. Chemical toilets were seen in remote low income areas used

by single individuals. Attempt to use chemical toilets in a small restaurant

in a rural region in Colorado resulted in failure apparently due to system

overloading. Obviously the owner of this establishment was ill advised as this system should not have been installed in the first place.

C. 3 Incinerating Toilets

Incinerating toilets have their merits since they leave hardly any residue

requiring disposal; however, with the rising costs of fuel, their operation

costs limit their advantages, and therefore, their application to home

installation is questionable. Gas fired incinerating toilets were observed

in summer homes in remote rural areas. The toilets were very favorably

accepted in spite of their high operation costs. Electric incinerating

toilets were observed in public facilities. One system visited was abandoned

because it emmitted offensive odors through its vent during the incinerating

cycle, and caused discomfort to the neighbors in the adjacent homes. The

other toilet was observed in a public library. Its use was limited to the

71
library staff. The problem of offensive odor was witnessed in this system

also. It was noted that the incinerating time cycle is rather long (30 minutes).

Incineration may be interrupted prior to complete incineration for another

usage, however, this inherent feature of the long incinerating cycle is

undesirable. In comparison to the compost toilets, incinerating toilets are probably more aesthetically acceptable, also, the problem of offensive odors can be overcome by proper venting installation. However, the high running cost

of operation is inherent in the systems and probably discounts its application

for homes.

C . 4 Vacuum Toilets and Drainage Systems

Vacuum sewage drainage is used as an efficient medium for wastewater transport.

Its advantages are; the independency of the site on the topography of its

terrain and the usage of smaller conduits sizes as compared to the conventional

gravity fed systems. Vacuum toilets, incorporated in the system, require only

one to two quarts of water per flush. The following three case studies are briefly described:

1. White Flint Shopping Center in Rockville, Maryland. The system has been

in operation for three years and serves 150 toilets. The system was visited in

March 1979. The plumbing attendant expressed satisfaction with the system,

however, the following problems occur:

- Pipe lines get clogged when excessive paper towels and "handy wipes" are

used.

Problems with the flushing mechanisms.

- Loss of vacuum in the drain lines.

Excessive noise upon flushing

Incomplete cleansing of the toilet's surfaces.

2. Vacuum Sewage System in Carmiel, Israel [6]. The system was constructed

in 1967 and served two hundred families most of whom lived in apartment houses.

The following problems occurred frequently:

Loss of vacuum in the drain lines.

Clogging of the drain lines because of flushing bulky materials and because

of formation of calcium deposits in the lines.

Failure of the toilets intricate flushing mechanism.

Excessively high noise upon flushing the toilet. A fact which aggrevated

the system had been its design, which was in a series configuration such

that any failure incapicitated all the homes downstream. The investigator

had spent a day at that site in 1973. On that day a maintenance crew had

been trying an acid dose treatment for clearing the deposit formation

in the drain lines. Fortunately, a redundant conventional sewage system was constructed with the vacuum drainage. As the problems increased in

frequency and severity, a time was reached that it was more economical

to abandon the system and replace it with a conventional standby system.

72
3. Vacuum System in Nassau, Bahamas [7]. The vacuum sewage toilet system

has been used in Nassau for over ten years. Some 1000 units have been reported

in 1977 which serve private apartments, a large hotel and public housing

projects. A report issued [24] indicates similiar problems as described for

the system in Israel. The economic analysis in that report indicates that

from the costef f ectiveness view point it would be desirable to abandon the

system and construct a new conventional system instead.

It is apparent that the vacuum drainage-toilet system needs major improvements,

in particular, in the design of the toilet, to make it feasable and more

reliable for residential application.

C. 5 Aerobic Wastewater Treatment

Aerobic systems have been in use for the last two decades and are approved by

some states plumbing code such as Maine and Pennsylvania. The following

statements appear in the brochure of an aerobic system manufacturer:

"By changing the existing septic tank from anaerobic state to aerobic,

not only will the efficiency of biological decomposition increase* from

15-30 percent to 80-95 percent, but it will reconvert the seepage fields

and the soil around them back to their natural aerobic condition" ...Since

the wastewater effluents then have a high dissolved oxygen (DO) content,

it develops an attractive environment for air breathing microbes ...to

rejuvenate the soil by controlling the propagation of bacteria, thus

keeping soil pores open."

These positive statements on the performance of aerobic processes are backed

up by several researchers such as Dr. A. Bernhart from the University of

Toronto who states that [8]

"A seepage bed area of about 700 sq. ft. using soil infiltration and

evapotranspiration is sufficient in clay-loam soil under aerobic conditions

while 14,000 sq. ft. are required if conditions are anaerobic."

These findings are highly favorable; however, no other known researcher was able to duplicate or come close to such results. It has been claimed that the

energy generated in the form of heat in aerobic processes also contributes to

increased evaporation at the soil absorption beds. Theoretical calculation of

this heat production indicates that the heat contribution to evaporation by

aerobic decomposition amounts to less than one percent [9], Most of the research

findings indicate a marked reduction of the BOD effluent of the aerobic systems

as compared to the reduction in septic tanks but no appreciable differences on the reduction of the total suspended solids in the secondary treatment effluents.

In septic tanks, reasonably representative figures will be a reduction in BOD

from 200 mg/1 to 160 mg/1 as compared to aerobic systems where the reduction is

from 200 to 40 mg/1. It has been recommended to apply these facts in sizing of

waste disposal fields with the use of the following equation [8]

i

/BOD + SS

Ae = As / 250

73
Where

"As" is the required area with use of a septic tank and "Ae" is the

adjusted area when an aerobic unit is used. "SOD" and "SS" are the

values in mg/1, the biochemical oxygen demand and the suspended

solids of the effluents from the secondary treatment system.

An inspection of this equation shows that even for very favorable conditions

an aerobic system will yield only a 20 percent reduction in field sizing.

Some states allow for a reduction in the absorption field when aerobic units

are used. Table 8 and the following statements are taken from the code of

the State of Pennsylvania.

TABLE 8

Absorption Area Requirements for Single Family Residences

Comparison Between Septic Tanks and Aerobic Tanks

(a) "The following figures shall show absorption area requirements

for the effluents of single family residences, including allowances for

garbage grinders and automatic sequence washing machines":

ft Septic Tanks Aerobic Tanks

Average Percolation Rates Z (Sqi. ft. /bedroom) (Sq. ft. /bedroom)

0-5 min/ inch

6-15 min/ inch

16-30 min/ inch

31-45 min/ inch

46-60 min/ inch

61 or more min/ inch

unsuitable

175

250

300

330

unsuitable

unsuitable

120

170

200

220

unsuitable

It is noted that the effectiveness of aerobic systems is still subject to

opinions by various professionals in the field. When a comparison is made

between the performance of septic tanks and aerobic units, the viability of

the aerobic systems is questionable. The aerobics require a smaller size

of soil absorption systems, however, their higher capital costs, power and

maintenance cost probably overshadow their benefits. The field inspection of

30 aerobic systems seen indicated that one third of the installations had

some form of failure such as pump breakdowns, improper functioning of the air

diffusers and malfunction of the control systems. Some systems were not

properly maintained and some were entirely abandoned because of lack of

replacement parts and/or excessively frequent failures.

Therefore it has been the tendency of various researchers to retain the septic

tanks which require very little maintenance and direct the efforts towards the

improving the performance of soil absorption systems.

C. 6 Mounds

Twenty mound system installations were observed in the field trips. Most

systems performed adequately, retaining a dry surface in their immediate

surroundings. Failing systems were observed in Montgomery County, Maryland.

74
The ground around these mounds was soggy, which indicated that the underlying

soil was of very marginal properties and could not absorb the effluents coming

from the mound. Reasons for failure may be attributed to poor construction

practices such as soil smearing or soil compaction at the time of the system

installation, which upset the natural permeable properties of the soil and

caused an early failure of the systems. A large amount of mound failures were

also reported in the state of Pennsylvania [10] . The reasons for failure were

because the underlying soil was of extremely heavy clay; also, the systems

constructed were gravity fed mound and not pressured, which may have resulted

in uneven effluent distribution in the mound.

When properly designed and constructed, a mound is an appropriate alternative

to conventional soil absorption systems. Mounds may be constructed to

properly blend with the home and its surrounding landscape.

Mounds receive the wastewater effluents from either conventional septic tanks or from aerobic treatment tanks. As mentioned earlier, it is claimed by some professionals that the performance of the mound is more effective with aerobic

wastewater effluents as compared to the septic tank effluents. This argument

needs further study and verification.

C. 7 Evapotranspiration (E-T) Beds

As mentioned earlier, the performance of E-T beds is more sensitive in comparison

to mounds systems as they form a closed system and do not depend on the soil

surroundings. They are also dependent on climatic conditions. E-T beds were

observed to work very well in the state of Colorado and probably work well in

any region of relatively dry climate and low precipitation. The adequacy of

their performance in areas of high precipitation is marginal. Systems observed

in the east were not entirely successful. A system observed in Kentucky was a total failure. The E-T bed was soggy with puddles of water in some areas causing inconvenience to the homeowner. A similar mode of E-T beds failures

were observed in Montgomery County, Maryland.

Evapotranspiration beds are designed according to the following equation [11]:

(V/A) = ET - P

3 where: V = total volume of effluents to^the bed in meter

A = area of the E-T bed in meter

ET = evapotranspiration in a water column in the bed in meters

P = precipitation in meters

V/A = the water column in the bed in meters

This expression represents the balance between wastewater loading, evapotranspiration and precipitation required at all periods and obviously the

period with lowest "ET" and highest "P" values are the critical ones. If

disposal is entirely dependent upon the bed, the value for (ET-P) should be

positive at all times, namely, evapotranspiration should exceed precipitation. This situation rarely exists in most regions east of the Mississippi

River where at least one of the following climatic factors are prevalent:

high precipitation, low temperature, high humidity and snow. Thus, the

feasibility of E-T systems in such areas is questionable, as indeed

witnessed in the systems observed in the East.

75
TABLE 9

Failures or Malfunction of Onsite Wastewater Systems Reviewed

System Mode of Failure Possible Cause of Failure

Composting Toilets Strong odor from toilet System overloaded

Large Volume Type Accumulation of liquids

in tank

Vent pipe clogged

Composting Toilets Unbearable smell Too many users (4)

Small Volume Type Flies hovering all around

No decomposition of wastes

High accumulation of

liquids

Improper venting

Improper dosing of

composting agents

(observed in several

cases

)

Incinerating Toilets

Electricity Operated

Strong odor from vents

Long time of incineration

Improper vent design

(observed in two cases)

Chemical Toilet Strong odor from toilet Malfunction of

recirculating pump

Over usage

Improper choice of

system for its

purpose of usage

Oil Flush Toilets System observed in a state highway rest area

Dirty surfaces in the

toilet’s well

Note: This improper

functioning was observed in one oil*

flush system. Another

manufacturer coats the

toilets with tephlon

which apparently

provides for better

cleansing of the

toilet in which case

no foul surfaces were detected

.
Table 9- continued

System Mode of Failure Possible Cause of Failure

One system observed incorporated an incinerator for the

disposal of the waste. The system encountered operating

problems resulting in incomplete incineration of the

wastes with exhorbitant costs of oil fuel.

Microphor Toilet Water splashed out of the

fixture during flush.

The flapper valve did not

seal the bottom chamber when

pressure was applied.

Note: This was noticed in one toilet only and may not

be a prevalent problem.

Vacuum Toilets Relatively high noise Noise is inherent with the

level upon flushing present design

Improper cleansing of Water does not reach all the

the bowls bowl surfaces

Blockages (not frequent) Use of paper towels and

of the drain lines diapers

Another system observed Most problems were

in Israel (1971) attributed to improper

encountered the design and improper

following problems: maintenance. Noise level

- Blockage in lines is inherent in the

- Failure of the flushing

mechanism

- Loss of vacuum (leakage)

- Blockages of the traps

system's operation.

and the PVC drainage pipes

- High noise level

Aerobic Tanks No aeration Failures were observed in

30% of systems seen:

Sewage has a dark grey - Aerator pump breaks

color, formation of - Malfunction of the

scum with unpleasant controls such as freezing

odors. of the relays and timers.

- No provisions for system'

restoration after

electric power failure

- No maintenance

77
Table 9, continued

System Mode of Failure Possible Cause of Failure

E-T Beds Flooding of the bed Improper sizing of the bed

Bed is soaked with with

waste effluents

Area subject to high precipitation

Bed located in low ground receiving

water from the surroundings in

addition to the waste effluents

Moun ds The slopes on the mound

and its surroundings

are soggy and muddy

- Mounds base is located on very

heavy clay soil

- The mound was constructed with

improper soil material

- The aerobic unit has not been in

operation for quite some time

- Generally very poor maintenance

of the system (as readily

observed by the wild growth of

grass and vegetation on the

mound)

78
D . Onsite Wastewater Demonstration Projects

Any onsite wastewater demonstration project entails the introduction of an advanced wastewater technology for presenting feasible solutions tp one

or more of the following problems which exist in the selected site:

1. Conventional systems - very costly. (i.e., problems of small

communities, in particular, in rural spafcely populated areas).

2. Failure of existing conventional wastewater systems.

The systems do not meet the wastewater effluent quality criteria

and may be an environmental hazard and/or a nuisance to the

community.

3. Conventional wastewater systems consume too much water in a region

of limited water resource and wastewater reuse devices are needed.

4. Conventional systems cannot be accomodated in the site because of

space, topography and geological constraints.

5. Conventional systems are not permitted by regulation.

Sewer moratoria on existing centralized wastewater systems restrict

further housing development or septic tank construction permit was

not granted after a failure of the onsite soil evaluation test.

The measure of success of any demonstration project is the realization that the

selected wastewater handling/ treatment system provided an adequate solution as indicated by the inspection, monitoring and laboratory sampling program, and

from the feedback furnished by the homeowners while the systems were under

observation. Beyond the project demonstration period, the same maintenance

should continue as the project, in effect, still goes on. The system may be

considered to have accomplished its goal even if the system failed provided

that clear and sound conclusions were drawn from it for future alterations and

improvements

An overview of demonstration projects observed on the sites visited and

studied from the literature is presented to point out successes and failures

resulted from improper system planning, design, construction and/or maintenance.

Section 6, "Requirements for Demonstration" outlines the minimal essential

requisites for a demonstration or any project of innovative nature. In the

following reviewed cases those criteria were not fully met.

Vacuum Sewage System in Carmiel, Israel [6]

The town of Carmiel is situated on a rocky steep terrain and has had limited

water resources. Thus, water shortage and wastewater transport problems

necessitated an alternative wastewater system. The vacuum sewage system

seemed to be a viable wastewater alternative as it provides a solution to

both problems. The system was installed in 1967. The problems, which were described earlier in this report were increasing in frequency until finally

the system was abandoned in 1973.

79
The following reasons for failure of the system can be partly attributed to

improper planning and partly due to unanticipated problems which may occur with innovative projects:

o Improper design of the drainage system. The wastewater transport system

which was constructed in a series arrangement certainly aggrevated the

situation, as localized problems propagated downstream and upset a large

size of the plumbing network.

o There was no planned maintenance program and no periodic inspection.

o The problem of system rejection by the users because of the toilets

noise upon flushing has been a serious one and could possibly be avoided

by preliminary testing; in which case the system probably would not have

been installed. One may note, however, that in similiar installations

in the Bahamas no complaints of that nature were expressed by the occupants of the dwellings.

The significant positive feature in this project was the construction of a redundant conventional system which was successfully taken advantage of,

almost as soon as it was decided to abandon the vacuum system.

Boyd County Experience [12]

Boyd County Demonstration is a project initiated by the Appalachian Regional

Commission which funded 100 percent of the equipment and maintenance for the

first year. The project is situated in the State of Kentucky in the heart of

Appalacia, a rural sparcely populated region of very low to middle income

families. Conventional centralized sanitation facilities would have been

too costly and septic tank systems not reliable since the local soils cannot

provide adequate percolation. The project objectives were to demonstrate the

feasibility of innovative onsite individual wastewater systems. The project

employed a "system approach" where the community’s individual wastewater

systems were managed by a County Sanitation District. This public body took

responsibility for supervision and maintenance of the systems. As a start,

the project entailed 36 homes which incorporated wastewater systems of various

configurations as follows:

Aerobic units from six manufacturers

- Disposal systems such as E-T beds, sand filters with stream discharge

and leach fields

Wastewater recirculation for toilet flush reuse

Continuous test data (1976, 77) indicated reasonably careful monitoring and

data collection program of the pertinent wastewater parameters.

A one day trip in the winter of 1979, observation of some of the installations

in the homes, and a talk to some of the homeowners indicated various aspects of

the systems, both positive and negative:

80
Aerobic System with Effluent Recirculation for Toilet Water Reuse

The system is composed of a holding tank which collects the aerated

effluent. The treated wastewater is then disinfected and recirculated

for toilet flush water reuse. The unit provided a significant

improvement to the homeowner who expressed entire satisfaction with

the system. Prior to its installation, he had acute water shortage

as his well did not deliver sufficient water to the household.

- Aerobic Units

Malfunction of the unit electrical control mechanisms.

Breakdown of the unit aerator pump.

System overloading.

Evapotranspiration Bed

Apparent improper design of the E-T bed resulted in flooding of the

front yard and caused a serious inconvenience to the homeowner.

The general impression was that except for the person receiving the recycling

device, the other homeowners were not concerned nor did they express appreciation

for obtaining these systems which probably did not add to their quality of life

appreciably. As it turned out, the systems were not maintained for quite some

time, apparently, for lack of man-power. Based on the general state of the

systems as observed at the time of the visit, the following criticisms may be

stated

Sustained satisfactory performance was not experienced as the

maintenance was not carried out throughout the period up to the

day of the investigator's visit.

- The benefits of the innovative systems of the project cannot be

fully assessed because the systems have not been appreciated by

the homeowners.

Garrett County Home Aeration Wastewater Treatment Project [13]

This project was conducted by the Environmental Health Administration of the

Maryland State Department of Health and Mental Hygiene. The project objectives

were the evaluation of aerobic wastewater systems subjected to actual working

conditions and testing aspects such as wastewater stress loading and detergent

foaming problems. The system was installed in Garrett County, Maryland, in

homes which "had experienced some degree of septic tank system failure." [13]

Five aerobic units manufactured by five different manufacturers were installed.

An extensive program of maintenance and sampling of the treated wastewater

effluents was conducted for a period of one year (1973, 74). This project may

be regarded as successful in as much as the outlined objectives within the

period were achieved. Also, the conclusions drawn from this project were

useful and provided material for future applications. However, a visit to the

site in the summer of 1979 revealed the following:

81
Out of three systems observed, two were entirely abandoned and one was not

in operation at the time of the visit. (The users would occasionally shut the

system down, apparently to conserve electrical energy) . Of the two abandoned

systems, the owners claimed that they had continuous pump failures but they

had no one to turn to for maintenance and repair. In one case, the owner

expressed dissatisfaction with the system since black partially treated

effluent comes from his soil absorption system and flows by gravity to a ditch

alongside his house. In the second case the aerator pump broke. The aerobic

unit has been functioning as an ordinary septic tank. The anaerobic effluents

flow from the tank, by gravity, to some form of a soil absorption system located

alongside Deep Creek Lake. The pump failure caused no concern to the owner, as

it did not create any noticable problems. It is apparent that in the latter

two cases the failure of the systems did not affect the owner terribly, since

otherwise they would find some way to ameliorate their situation. This fact

poses the question whether these sites were a proper choice for demonstration.

It is probable that prior to that project the degree of failure of the existing

wastewater disposal systems was not very severe so that the effect of the

innovative system cannot be assessed and evaluated.

Montgomery County (Maryland) E-T Systems Demonstration [11]

This project for evapotranspiration systems was initiated by the Office of

Community Development (OCD) in the county and funded by the Metropolitan

Washington Council of Governments (COG). The project objectives were:

1. To determine the feasibility of Evapotranspiration in the Washington

Metropolitan Area.

2. If E-T beds are found to be feasible, present recommendations of E-T

systems, regarding design, construction, and operation.

Five E-T systems were installed in the county in the summer of 1977 with the

following variables and configurations:

- Geometry: bed, trench, mound.

- Treatment Type: septic tank, aerobic tank.

Base Lining: no base lining, with plastic lining.

The systems were under observation for one year during which the parameters

related to weather, flows, chemical and biological conditions were sampled and

measured on a weekly basis.

In their final report the researchers concluded "that the test system did in

fact accommodate the flow pattern generated." Their finding, though, indicated

that two of the sites did exhibit problems of overflowing and ponding.

A recent visit to four of the five sites revealed the following:

Ponding of effluents in all the sites, two of which had dark

liquid with foul odor surfacing. In the two systems containing

82
the aerobic treatment tank, one was in operation and the other seemed to be

abandoned. The project may be criticized in thefollowing areas:

1. Lack of continued maintenance resulted in obscuring the outcome

of the project as conclusions cannot be drawn regarding the

feasibility and effectiveness of the system.

2. Conclusions reflected in the final report were perhaps premature, as the

system was under observation for only 12 months whichis not a sufficient

period for conclusions and final assessments for systems which are strongly dependent upon climatic conditions.

3. The demonstration was conducted on a small scale with a small sample size,

and too many variations of systems configurations. A better approach

would have been to reduce the number of variables under study and concentrate on one or at most two parameters, so that more meaningful and

conclusive information could have been drawn for the monitored period and

beyond

Shortcomings and Limitations of Demonstration Programs

It appears that demonstration programs may have the following shortcomings:

i 1. Insufficient collection of data on the sites prior to the project start.

If this information is not complete, full assessment of the demonstrated

innovative system cannot be obtained.

2. Insufficient funds or manpower for providing adequate maintenance

and observation. In this case, the system may fail and the project will

be self-defeating with erroneous conclusions drawn from it.

3. A small sample size for the demonstration. A small sample size will

furnish results with little statistical significance. The size of the

project depends on the available funds allocated for the project;

however, if funds are not available for a sufficiently large project, the

usefulness in starting the project is questionable.

4. Insufficient time for system observation. Sufficient time must be

allocated to ascertain that a steady mode of operation was achieved

so that the system will continue to operate in the same mode after

the demonstration project had officially ended.

5. User's acceptance, cooperation and participation. The success of a demonstration project depends to a very large extent on the users’

acceptance, and the project’s importance in solving the immediate

wastewater problems. It would probably be advantageous if the homeowners

participate in some of the equipment cost. As seen, free systems given

to the homeowners were not always appreciated and consequently not

maintained

In the above described demonstration projects, at least one of the

categories was not met.

33
E. Aspects of Onsite Wastewater Systems

E. 1 . The Aspect of User's Acceptance

The problem of user's acceptance has its impact to various degrees in most

innovative wastewater systems. Contrary to conventional, centralized systems,

which are taken for granted, innovative systems require considerations which

range from periodic system check to an overall radical change of the homeowner's

personal habits and life style. Any required awareness from the users has a nuisance demerit and affects his general attitude. The vacuum toilets produce

a high sound upon flushing and may be disqualified for that reason alone. The

composting toilets require a radical change in habits and attitude, from the

standpoint of daily usage and maintenance. Their external shape may be

appalling and, as mentioned earlier, a considerable percentage of people are reluctant to use these devices.

The problem of acceptance is a concern and a subject for numerous surveys

conducted on attitudes towards the usage of reclaimed water. Table 10 indicates

the results of the survey conducted by "Pure Cycle" [14] on consumers attitude

in drinking recycled wastewater. These results may be encouraging to Pure Cycle

as only 24 percent are crossed off their list of prospective customers of

wastewater package system. However, from the community view such results are discouraging if one considers a large community recycling system which may be

imposed on the community as a w*hole. A more detailed survey was conducted in

the State of California [15] and included ten communities with a sample of 100

per community. This survey examined several parameters involving the attitude

towards various usages of recycled wastewater such as garden irrigation, fishing,

bathing and drinking. Table 11 indicates the degree of acceptability for these

usages. In addition, these surveys indicated that acceptance is a function of

the user's educational level, a well known fact which has been established in

other studies too. Table 12 lists the relative frequencies for reasons of

nonacceptance of full reuse of reclaimed wastewater. It is noted that the

psychological reason is the most dominant factor. Apparently, people who

expressed resentment did not know the fact cited by EPA that 50 percent of the

population of the U.S. drink recycled water of some form or another. Therefore,

the major effort for the promotion of innovative systems has to be through

public education by various dissemination programs and the news media.

E. 2 The Aspect of Codes Acceptance

Codes and regulatory agencies may be viewed as agents which block the promotion

of innovative wastewater technology or as buffers against the introduction of

devices which may be a threat to public health due to water borne diseases or a nuisance to the homeowner because of problems such as mechanical failures and

excessive maintenance. Almost all innovative systems have the inherent problem

of lack of experience, incomplete data base for evaluation and some probability

of failure. Therefore, the incorporation of innovative systems into codes is a long process and the following two questions are raised by legislative personnel

and manufacturers:

84
TABLE 10

Results of the Survey on Attitudes Towards

Recycled Wastewater Conducted by "Pure Cycle"

Does the idea of drinking recycled water bother you?

Yes 28%

No 67%

Don't know 5%

Water recycling is the reuse of sewage and waste water after it has

been purified. If the quality of the recycled water is as good or better than municipal water, would you drink recycled water?

Yes 76%

No 18%

Don't know 6%

Do you think ways of recycling household sewage and waste water

should be studied and made available to the homeowner?

Yes 94%

No 1%

Don't know 5%

If a water recycling system is completely fail/safe, would you

favor or oppose the use of such a system?

Favor 81%

Oppose 11%

Don ' t know 8%

85
TABLE 11

Public Attitude Ratings Towards Reuse for Various Usages

Conducted by the State of California

Use

% of acc . a Rank Acceptability category

Garden irrigation 88.4 4

Toilet 88.3 3

Park/golf course 87.7 1 Factory 87.6 2 Most acceptable

Farm irrigation 83.6 6

Scenic lakes 82.9 5

Boating/ f ishing 72.4 7 Laund ry 67.3 9 Moderately acceptable

Beaches 65.9 8

Bathing 61.4 10

Food canning 49.5 11

Cooking 48.1 12 Least acceptable

Drinking 39.1 13

TABLE 12

Relative Frequencies for Reasons of Nonacceptance

of Full Reuse of Reclaimed Wastewater

Conducted by the State of California

Reason Percent

1. Psychological 43.7

2. Lack of purity 16.4

3. Can cause disease 10.3

4. Lack of experience 9.2

5. Danger through improper plant operation 7.2

6. Undesirable chemicals added 5.6

7. Prefer other sources/methods 3.1

8. Taste/odor problems 2.1

9. Body contact undesirable 1.8

10. Unreasonable treatment cost 0.7

86
If data and field experience is not available, how could the system be

approved?

If the system is not approved, how is it possible to obtain sufficient

field data?

Review of plumbing codes make one realize the large variations in procedures

and requirements. Table 13 presents minimum and maximum values for conventional septic tank soil absorption systems as specified in the State Codes.

These variations are for systems that have been in use for several decades.

These differences cannot be explained and are not related to any scientific

findings nor can they be attributed to climatic or other specific requirements

among the states. If such variations exist for conventional systems, one may

expect larger variations in innovative wastewater systems. Table 14 is a compilation of the onsite wastewater policies [16] as administered by all the

states in the country.

Policies vary from state to state and also between counties of the same states

as described in Table 14. One may even find special regulations in townships.

The tendency is generally to stay on the conservative side and approve innovative systems in special conditions such as replacements of failing systems.

The State of Wisconsin still does not approve the construction of mounds in

spite of the experience and know-how gained in the state through the University

of Wisconsin. This state will approve only 3 percent of mound construction

requests throughout the state and a maximum of 5 percent for an individual

county. Boulder County in Colorado will let ten innovative systems be constructed for observation. The State of Maine [17] may be noted „as having a plumbing code which includes progressive approaches and regulatory provisions.

This code specifies requirements for experimental systems, allows for the

reduction of soil absorption fields when water saving devices are used and

approves waterless toilets such as chemical toilets, compost toilets and

incinerator toilets.

It may be noted that the national plumbing model codes do not specify

requirements for innovative systems. Requirements for onsite wastewater

systems are specified only for septic tanks and conventional tile fields.

E. 3 The Aspect of Health in Onsite Wastewater Systems

The problem of health and safety of wastewater systems has been very much

debated and various views have been expressed. This problem was very well

addressed and defined in [18] as follows:

"From the public health point of view, there are two basic criteria for the

safety of an onsite system:

Is the system safe in terms of disease transmission in theory?

Is the system safe in terms of disease transmission in practice?

87
TABLE 13

Maximum and Minimum Values for Areas Septic Tank Soil Absorption Systems

Required by State Codes

Subject Maximum Value Minimum Value

Septic tank capacity in gallons

by number of bedrooms:

1 bedroom 1000 500

3 bedrooms 1500 900

Setback distance drainfield to

well in feet 300 50

Required soil depth below bottom

of trench in feet—min. 4' no minimum

38
1ABLL 14

Onsite Wastewater Policies by States

8

tsl 3

3

23

U)o

1. Permitting Authority:

State • a • 0 • • • • • • Local • • • 0 • • m • • 0 • • Other 0

2. Minimum State Rule*? • « • 0 0 • 9 • » • • • 9 %

3. Alternatives used: Convent lonal ly • • • 0 0 • _ • 9 • • -2—1 • Expei lac in a 1 1 y • • • 0 • 0 • • • . • •

A. Alternatives.

Septic Tanks • • • 0 0 # • • • % •

• I

I • 9 Home Aerobic Plants • • 0 • • 9 • • • • • % Bleckwater Recycle Devices •

1 I Greyvater Recycle Devices Integrated Black-Creyvacer Devices Composting Toilets

Tile Fields Elevated Sand Hounds

ETET-1 Pressure Sewers Vacuus Sewers Grinder Pumps Wastewater Incinerator*

Other*

• • •

1 - 4— —1— 4 % — 1 • • # • • • • 1 » •

1

• • • 0 • • 9 0 \ • ».L •

1 •

1

• 0 0 0 0 • • •

• • • • • • •

0 0 • # • • • • i • • • • 9 • • •

» %

• • • # • • -2—|

• •

•

1

Recirculating

Flltera

Stabilization

Ponds

"O

CC 41 T3 w

C 3 C -C

a. —

ho C md C C

aw 2

«

s. U = i

JZ X

® 0

V5 a. |

l>oub

1e

Sand

Filters

1 -

r: -3

c oJ • | <s. -|

we m

•D c/M C

J

6L «kj

J L

3. Tile Field Sizing Criteria

Reduction for Hoae Aerobic Plente? Surface Discharge Permitted

Filtration Required Disinfection Required

F Std. 40 Used Conformance Tasting Required

Use By Law

Code Regulation

Policy

Listing Required

AiiHilonal Teaclna Reouirad

No.

Bedras,

Garbage

Grind..

Wash.

Mach.

USPHS

Manual

Perc

Teat

Soil

Survey,

Perc

Teat,

No.

Bedrms.

Perc

Teat

USPHS

Manual s

0

*-» c

IT. u

01 *o

fr- 01 m

u

u

oi c

a. z

Soil

Survey

Perc

Teat

Perc

Teat

Anticipated

Flow

Perc

Test

m

3ei

(/i s

Oo

C/3 3

s

0

0> 0 1 i

A

u

ho • 41 0

a- z

Soil

Survey

Perc

Test

>

u.o

41

in <t £

^

4) S — <

3

W

- x ! ft.

0. LT. 0. Z

• #

• • 0 • • •

t

0 • • • • • • • • • • • 0 •

• •

•

• # • • • • • • • .

1 • • • •

6. Are Recycle Syetcas UeedT Fluid Used For: Flushing Only

Lawn Watering

Laundry

Showe r Drinking

• 0 • •

0 9

• • 0 0 • 0

r

, •

(1)

7. Program Change* Prompted 0 • • •

i MSP PU* Copy Law

Code Regulation

Policy

9 • ] #

a % • • 1 • 0 % • t • f

• • • 9 • 0 # • 0 • ]

Compiled from "Onsite. Wastewater

Treatment Alternatives" by "ASTRE"

(Applied Science Through Research & Engineering)

(1) Policy virlM from county to county

(2) Only permit septic tank /til* field laatallatlam*

(3) On* aultlple county health department

(4) NSF or equivalent required

(3) Local laalth Oapartaaat* are ea aataaalaa •( U< State IT tvapo transpiration

*T-1 trap* traaapl rat lea -Lai lit rat lea

89
TABLE 14, CONTINUED

e a

1. Permitting Authority:

State • • • • • 9 a • 0 9

Local • • • • a • • • • ' 0 0 9 •

Ot he r • 2. Minimum Scale Rules? • • 9 • • 9 9 9 •

3. Alternatives used: • • • • • 9 ~Tj

Conven c ional 1

• # • • • 0 • • • • • • E*pe r 1 mental ly • • • • • • *

4, Alternatives:

Septic Tanks • • • • • 9

• • • • •

• 0 r^—

a • | Home Aerobic Plants • • • • # 9 • • , Blackwater Recycle Devices • • •

' Greywater Recycle Devices • Integrated Black-Creywater Devlcea m • 9 • 1 Composting Toilets • 9 0 • • • • • 9 •

1

Tile Fields • • 0

Elevated Sand Mounds 9 9 • • 9 aim! 0

ET 0 • • • e

1 e 9

ET-1 Pressure Sewers Vacuus Sewers Grinder Pumps Wastewater Incinerators

Others

• • 9 • ! *

\ m • • • 9

. m 9 • 9 • 0

• 9 • 0

•o§ ffi «u u

a? a w

o —

Aw U. m

*T3 *0 5 J

•

u

93

JCu

ace1

2

Lagoons,

ElectroOsmo

..

Overland

Flow

Sewage

Osmosis U2

in •

c *

0

c t

ac c

•§

0

to•

.J

•

e

0

0m

2

A

H

c 1 3 1 C T- U «| C X! » Uj

« c. • 1 0 >

a.

8 l mi V)

5. Tile Plaid Suing Crltarla

Reduction for Home Aerobic Plante? Surface Dlacharge Permitted

Filtration Required Disinfection Required NSF Std . 40 Used Conformance Testing Required

Use By Law

Code Regulation

Policy

Llatlng Required Additional Testing Required

ca

O 1/5 X X

a.

• t/3 AW 3

m« -

U *T3 ,2.8

Perc

Test

Soil

Profile

&

Site

Evaluation

Soil

Profile

&

Site

Evaluation

Perc

Test

Anticipated

Flow

Perc

Test

HUD

Std.

a

c

(aT

4 • a a c H

(. £3

USPHS

Manual

Perc

Rate

«

•

it H

Uu

V

aSoil

Profile

and

Site

Evaluation

Perc

Test,

Soli

Pro-1

file

&

Site

Eval.

Perc

Test

USPHS

Manual

>

C 3

C —

— a. • TT 3 V

<c •

> a

UJ —

5. 3

• • f • • 9 •

•

• 0 • • • 0 9 • • 9 • 0

• •

a 0

• 9 T 9 0 0 • (4) • 9 • • •

6. Are Racycle Syatema Used? Pluld Used For: Flushing Only

Lswn Uecerlng

Laundry

Shower Drinking

Other

• 0 • •

• •

0 •0

#

7. Program Changes Prompted

By 1977 Clesn Weter Act DSP Pile Copy Lew

Code Regulat Ion Policy

• • 0 •

9 • 0 0 9 m

• • _3_i

(1) Policy varlaa from county to county

(2) Only permit aaptlc tank/tile field lnatallatlooa

(3) One multiple county health department

(*) «SF or equivalent required

(3) Local Health Departments are an eatanaloo of Che State IT leapotranaplratlon

IT-1 •eapotranaplratloo- Infiltration

90
TABLE 14, CONTINUED

<

H

C

E

0coz

0

1

8

£o

UJQO

5

<

5 u*

U4CO

on on 5B

£

§

<

Z

c

at> s

1. Permitting Authority:

State

Local

lit her

r

-

1 0 • 0 • • 0 0

1 • 0 • • • 0 _ 1 ni • . 2. Minimum State Rules? • 0 0 0 0 0 • 0 —• . 3. Alternatives used: Convent lonal ly Experimentally

0 0 0 0 0 0 0 • • • 0 0 0 0 0 0 0 0

• 0 0 0 0 0 0 0 0 0 4. Alternatives.

Septic Tanks

Home Aerobic Plants Blackwaier Recycle Device* Creyvater Recycle Devices Integrated B1 ack-Greyvater Devices Composting Toilets

Tile Fields Elevated Sand Mounds

ETET-1 Pressure Sewers Vacuum Sewers Grinder Pumps Waatewater Incinerators

Others

• • 0 0 0 0 •

j •

• • 0 • •

0 • rr^

0 • —

0 0 0 •

Y — 1 0 • 0 0 0 0 • • • • • 0 0 0 0 • • 0 • ^Tl

0 0 0 0 • • 0 •

0 0 0 0 • 0 • 9

0 0 0 • • 0

0 0 • • • •

0 • r —

0 0 • 0 • 0

m

e

0

0

«c Spray

Irrigation

Pressure

Dosing

Gal

leys

Flow

Diffusers

c

0

a.aoW

9

at m*A

m

in

1

j

>- o

43

a.

J. Tile Plaid Siting Criteria

Soils

Evaluation

Soil

Survey/Prof

lie

No.

of

Bedrooms

Perc

Test

i i

V 0

a. ou

•

4) a* -s 03

O 0

u z

a.—1 u — •

0 41 in

Soil

Profile,

Perc

Test.

No.

Bedrooms

Soil

Profile

1

Perc

Test

I

Anticipated

Flow

i

Soil

Survey,

Perc

1

Test.

Antic.

Flow S

oo

u

•o M 07 « ca V

f- o

u

4) 0

0. z

Perc

Test

No.

of

Bedrooms

Pare

Teat •

•H

Uw

0

4-

|Jn m

a. 0

3

Induction for Home Aerobic Plants?

Surface Discharge Permitted

Filtration Required Disinfection Required

1/3 'll 1

1 • • 0 0

1 • 0 0

0 0 I MSP Std. 40 Used Conformance Testing Required

• • • % • • • • • 0 0 |

•

j Use By Law

Code Regulation

Policy

Listing Required

Additional Testing Required

| 0

j 0 • •

1 • • • 0

(4 ) • 0 • • • 0 • i i • • 0 •

J •j 6. Are Recycle Systems Used? Fluid Used For: Flushing Only

Lawn Watering

Laundry

Shower Drinking

Other

0 • • • • |

0 • • • 0 0

0 • • • i i 0 • 0 -i •

| •

i • 1 7. Program Changes Prompted

By 1977 Clean Water Act 0

1

MSF Pile Copy Lav

Code Regulation

Policy

•

0 0 0 0 • 0 • • • 0 0 •

•

(1) Policy varies from county to eomty

(2) Only permit septic tank/tlle field Installations

(3) One multiple county health department

(4) NSF or equivalent required

(3) Local Health Departments are an cstcnalon of the State

ET Evapotranaplratlon

ET-1 Evapotranaplratlon- Inf lit rat Ion

91
From the theoretical point of view, any safe system must isolate potential

disease causing organisms from possible means of transmission by vector,

(agents capable of transferring pathogens) human contact, or water pollution.

From the practical viewpoint, the system must be relatively "fail-safe,"

or else adequate provisions must be made to insure that users of the system

will operate it in such a way that its performance approaches theoretical

criteria.

However, the question of public safety is not the same as public health

acceptability . Acceptability implies a value judgment in which potential

benefits are weighed against potential risks. Thus "safety" is an obj ective

quantitative measure of performance under theoretical or practical conditions,

while a judgment as to acceptability takes into account the human context of

the problem including preferences, economics, available resources, and needs.

Tables 15 through 18 indicate outbreak of diseases from various wastewater

systems [19]. Health authorities report outbreaks of hepatitis, diarrhea and

meningitis as a consequence of failing septic tanks. Reports indicate detection

of polio virus in 100 feet deep wells located 300 feet from the edge of a wastewater drain field. Viral tests were conducted by the University of

Florida [20] which revealed the presence of virus in 20 foot wells after heavy

rains. Alarms have been expressed on the microbiological hazards of household

toilets and the role of aerosols in the epidemiology of disease transmission by

toilets [21, 22]. Similar questions have been raised in regard to undisinfected

spray irrigation systems. For both cases, it was found that the particle size

of the aerosols are in the range capable of reaching the lower respiratory

tract. How severe these problems are 'in actual practice has not been established

as yet. These problems become more serious with the use of water-saving low

flush toilets and recirculating systems since their concentration of pollutance

in the wastewater effluent is expected to increase. Test data from the Pure

Cycle purified effluents indicate a very high degree of treatment. The

question always remains how reliable is that system designed to treat wastewater

to potable quality and what is the probability that some unforeseen chemical

agent or pathogene may enter the system without being detected by the built in

alarm and cause undesirable effects. Some quotations from a report issued by a medical epidemiologist [18] sums up the inherent problems of this matter:

"... In our opinion, it is not possible to do an analytic

epidemiological study which would yield conclusive results and

the money expended would be wasted . . . Accidents with composting

and reclamation will occur and though we do not believe that

hazard is great, the potential does exist for communicable

disease transmission."

The statement cited in reference [18] is more encouraging and has more practical implications, in particular, in policy making for innovative

onsite wastewater systems.

"... acceptability of a particular system must be determined

by local public health officers on the basis of the best available

information and experience together with particular needs and

conditions .

92
TABLE 15. WATERBORNE DISEASE OUTBREAKS

1971-1975

1971 1972 1973 1974 1975 - TOTAL

Outbreaks

Cases of Illness

19

5182

29

1638

26

1774

25

8356

24

10879

123

27829

TABLE 16. ETIOLOGY OF WATERBORNE OUTBREAKS

1971-1975

Acute Gastrointestinal Illness

Hepatitis - A

Shigelloses

Giardiasis

Chemical Poisoning

Typhoid

Salmonelloses

Enterotoxigenic E. coli

Total

OUTBREAKS CASES OF ILLNESS

63 17,752

14 368

14 2,803

13 5,136

12 511

4 222

2 37

1 o O 3

123 27,829

TABLE 17. WATERBORNE OUTBREAKS BY TYPE OF SYSTEM

1971-1975

OUTBREAKS CASES OF ILLNESS

Municipal Systems 37 18,633

Semi-Public Systems 70 9.058

Individual Systems 16 138

Total 123 27,829

TABLE 18. WATERBORNE DISEASE OUTBREAKS BY TYPE OF

DEFICIENCY 1971-1975

OUTBREAKS CASES OF ILLNESS

Untreated Surface Water* 19 5,729

Untreated Ground Water 38 3,958

Treatment Deficiencies 39 10,139

Distribution System Deficiencies 15 7 , 468

Miscellaneous 12 535

Total 123 27,829

* Includes seven outbreaks of giardiasis in which surface water was chlorinated

but not filtered.

•93
E. 4 The Aspect of Maintenance

Most failures observed in the field trips were attributed to the inadequacy

of maintenance of the wastewater systems. A system may be highly efficacious

in principle; however, lack of proper maintenance will be self-defeating for

the system, as its true capabilities could not be demonstrated. This happened

to the Composting Toilets which were criticized and attained some degree of

notoriety as failing systems. The reason for the failure of composting toilets

as observed in the trips was attributed to the user’s lack of information on

the workings of the system and consequently improper maintenance.

Aerobic systems are very susceptible to malfunction and require a considerable

Amount of maintenance. As earlier mentioned, a large percentage of aerobics

were observed to fail or perform inadequately because of mechanical failures

primarily in the control devices of the systems. The major aerobic system manufacturers are under the NSF testing program and these products bear the NSF seal

of approval. NSF tests these aerobics under simulated, controlled, field

conditions for a period of six months. Although the systems are subjected to

rigorous test programs which include elements such as "stress testing" and

"shock loading," these procedures do not entirely represent field conditions.

At best, one may say that these tests are reasonably good indicators to the

performance of actual conditions provided, the systems are treated in the field

in a similar way that they are being tested in the NSF laboratories which

generally is not the case . These facts strongly indicate that systems should

be approved only on condition that the homeowner submits a detailed maintenance

program which will be carried out by experienced personnel from the manufacturer’s staff or a local representative. Mention should be made of the company

John Fancy, Inc [23]. This company operates in the State of Maine as a maintenance and servicing outfit of aerobic wastewater systems. It serves some 450

systems on a contractual basis. Each system is visited at a frequency of at

least once in eight weeks for inspection and service. This company also provides

emergency service normally taken care of within two days. It appears that in

order that proper maintenance will be given, a planned and controlled program,

either by a private organization or a legislative unit, is imperative.

E. 5 Economic Aspects of Onsite Wastewater Systems

With the rising cost of conventional centralized wastewater systems, which

may reach $12,000 per "hook-up," onsite wastewater systems become more and

more attractive as an alternative cost effective system. With good soil

and site conditions, the septic tank - tile field is by far the most economic

wastewater treatment and disposal system. When the soil on the site is of

marginal properties, alternative systems should be considered. Aside from

performance of the system and capability in meeting effluent quality levels,

the costs of the system will be the final factor in the decision making

process among the available alternatives. The costs of the system will

generally be broken down into the following components:

1. First cost

System design

System cost of acquisition

System construction and installation

94
2. Annual or monthly cost

Maintenance and service charges

- Replacements of parts (pumps, compressors, filters)

- Power costs

Cost of disinfectants (iodine, chlorine)

Based on present or future forcasted interest rates and the system life, all

cost factors are converted to a common basis to furnish a total annual or monthly cost. Water conservation devices and recycle/reuse systems will include

a reduction in cost due to the reduced water consumption and reduction in total

wastewater influents. Unfortunately, many rating policies adopted by water

supply agencies do not provide for reduced rates with reduction of water consumption. Furthermore, some wastewater treatment companies base their charges on the B.O.D. loading; thus a reduction in the wastewater flow will not be reflected

in a reduction of the total charges of wastewater treatment and disposal.

Whenever possible, it will be more economically feasible to construct a system

common to a community or serving a cluster of homes as the total costs are shared by several homeowners.

The following is the first cost for an aerobic wastewater system-mound package

as presented by a consultant in a private inquiry for a cluster of homes as compared to a similar system for an individual home:

Individual System : (Jan. 1980 figures)

Aerobic Unit-One smal^ model

Mound System - 600 ft in area

Total Installation cost

$2500

2000

$4500

Community System (9 homes)

Two large aerobic units

A large 6000 ft mound

Total installation cost

$12900

20000

$32900

or $3640 per home

We note an appreciable saving per home for the clustered system, in addition

to the advantages in systems management and maintenance which is more sufficient

and economical for a community system as compared to an individual home. Other

systems are presently manufactured for individual homes only, but probably have

greater economic potential when designed for several homes or for an apartment

house. The following is cost of a recycled grey water system for toilet water

reuse as given by the manufacturer:

System cost

Installat ion

Sump pump (if required)

Maintenance and Materials

$3500

100 ($250.00 for retrofit)

250

80 per year

This system can be designed on special orders for more than one family. A

package serving a family of four will cost approximately $6000, (as quoted by

a manufacturer) a substantial reduction in cost per family. Some systems

cannot exist unless they are part of a large community. As mentioned earlier,

"Pure Cycle" in Boulder, Colorado manufactures wastewater package plants for

95
individual homes of wastewater treatment to drinking quality. The total cost

of the system is $10,000 (including average cost of excavation and construction).

However, the company requires some 150 units located in a radius of 50 miles

so that they can establish a center for monitoring and prompt servicing.

The concept of innovative onsite systems is relatively new. With the advance

of the state-of-the-art and with the incorporation of onsite innovative

systems into the public codes, patterns of normal usage will be evolved. As

the onsite systems become ordinary consumer products, an economic data base

will be established for system economic evaluation.

E. 6 Soil Evaluation for Wastewater Effluents Absorption Systems

There is no doubt that the soil underlying the homeowner's property is and will

always be the most effective and least expensive media for onsite treatment and

disposal of the household wastewater. The soils serve several tasks: as a wastewater purifying medium, as a wastewater disposal medium, as means for

groundwater recharge and may serve as a medium (if desirable) for replenishing

nutrients to the ground. The problem has always been to describe and quantify

the soil properties and parameters which play a role in the quality and transport

of wastewater from the secondary treatment device (septic tank, aerobic system)

to the ground. Construction of septic tank - soil absorption system with no prior soil evaluation or incorrect evaluation may result in the failure of the

system.

The procedures and requirements for soil evaluation vary among the various

legislative bodies in the country. Some require a "perc test" only and some require a broader, extensive 'test of general soil evaluation and has to be

performed by a registered evaluator. Perc tests have been traditionally used

for years. This test measures the percolation rate of water in the underlying

soil as an indicator of its capacity in removing the hydraulic loadings of the

wastewater effluents to the ground. This test is made by digging several

trenches in the lot to depths of four feet and 10 feet, drilling holes of six

inches in diameter and 12 inches in depth in the trenches and pre-soaking the

holes with water 24 hours before the test. Water is then poured to the holes

and the time for the water to drop one inch is recorded. The acceptable values

are in the range of five - 60 minutes per inch. It is often argued and

established by most professionals that this test is inadequate and certainly

insufficient to provide sufficient information on the soil characteristics.

In observing "perc tests" conducted in several sites in Montgomery County,

Maryland, it was noted in one test site, perc test values varied from seven to

240 minutes per inch. This large spread in values clearly indicate that the

validity of soil evaluation based on perc test is questionable.

In considering soil evaluation, the "perc test" as specified by most codes is one component of the soil properties. Soil evaluation in the broader aspect

includes the following soil and geological characteristics:

Soil Classification

The best known is probably the textural classification of the U.S.

Department of Agriculture referred to as "classification triangle"

where the percentages of the soil constituents, i.e., sand, silt,

clay, are determined (figure 21).

96
'h

percent sand

GUIDE FOR USDA SOIL TEXTURAL CLASSIFICATION

Figure 21

USDA Soil Classification

97
The nature of the constituents composition will serve to indicate soil

attributes such as soil absorption and water infiltration capacity. The

smaller the particle size, the larger the water retaining capacity due to

surface tension forces. On the other hand, the larger the particle size, the

larger the pores between the particles. Clay soils tend to develop a crusty

layer which impede infiltration.

- Geologic Characteristics

Physical and chemical composition and structural properties of

the underlying bed rock is examined. A bed containing fractured

bedrock may pass the effluents directly to the ground water.

Topography

The slope of the terrain is determined. Excessive slopes do not

retain water and cannot be used as soil absorption systems.

- Determination of High Ground Water

High ground water should not reach close to the soil absorption

system to prevent the contamination of the ground water.

Aside from these underlying natural conditions, the treatment of the soil while

construction takes place plays a role on the soil capacity. It has been shown

through research that soil "smearing" and soil compaction during construction

alters appreciably the soil properties.

All these properties make it difficult to describe the soil uniquely in

particular for design criteria for onsite systems. In reference to research

and demonstration projects, a detailed soil evaluation is of high significance

for the purpose of defining the input conditions and concluding for which soil

conditions was success or failure attained.

E. 7 Grey Water Systems

Segregation of the wastewater household into grey and black water has been

a topic of significant importance and research for the past decade [24, 25].

Wastewater separation to form two distinct household effluent systems offers

a potential for efficient handling as grey and black water differ in their

characteristics; in their total flow, temperature, chemical constituents and

biological aspects. A typical distribution in the home, of the major

parameters between the grey and black water is given in Table 19 [24].

98
Table 19

Distribution of Wastewater Loading Between Grey and Black Water

Parameter

Percent

Grey Water

Distribution

Black Water

Flow 65 35

bod

5 63 37

Suspended Solids 39 61

Nitrogen 18 82

Phosphorus 70 30

Pathogenic Organisms Very low Vast majority

These figures indicate that black water and grey water systems require different

wastewater treatment considerations, in particular, for the following aspects:

- Hydraulic loading of the system and physical sizing.

The oxygen demand of the system.

Soil absorption systems behavior.

Aspect of health hazards and disinfection.

Immediate application of wastewater segregation is required in the following

areas

Waterless Toilets

As waterless toilets gain acceptance, the households greywater treatment and

disposal form distinct systems. From the waterless toilets used at present,

the composting toilet of the ’’large type" is most widely used. Depending on regulatory requirements and the user’s options, the grey water is either

disposed of or reused for irrigation and gardening. Grey water treatment by

sand filtration and surface discharge was proposed by the University of Wisconsin,

as shown in Figure 22. Similar arrangements were observed at sites in the

State of Maine. The State of Maine requires disinfection of the effluents

prior to lake or ocean discharge which is carried out by chlorination or U/V

disinfection. Clivus Multrum, M.S.A., Inc. designed a "roughing filter"

composed of sand and pea gravel as in Figure 23, whose effluents are rendered

safe for gardening and green house applications.

Grey Water Recirculation for Toilet Flush Water Reuse

These systems were described in previous sections of this report. These

systems offer a substantial reduction in total wastewater loadings and a possible 40 percent reduction for water conservation.

99
Figure 22

The Clivus Multrum Grey Water Filter

INSULATED COVER

o VENT

j _ SPLASH

_Lk PLATE

1 DISTRIBUTIOIrr

• 1 *» ; .

' ' SAND

II* •

'

i L

- ’ ... PEA gravel’ '• *." *

• *• /.!

1 • ;

• ~ a “IT7 CGARSe'

° ; °

* STONE * *

» « • o » i- . • . * „ /V. - r : CONCRETE SLAB /

^COLLECTION PIPE

Figure 23

The University of Wisconsin Grey Water Filter

100
Grey Water Sweep Systems

Grey water may be used as sweep systems to supplement wastewater transport

requirements for efficient drainage performance. Such systems require only

storage facilities and control for occassional grey water release and

backflow prevention devices.

F. Additional Sources of Information on Onsite Wastewater Systems

The following sources of information are essential in any study on onsite

wastewater systems:

F.l Literature

Aids for Literature Search

NASA - National Aeronautic and Space Administration

Scientific and Technical Information Facility

Baltimore-Washington International Airport

P.0. Box 8757, MD 21240

Entering key words such as "onsite wastewater systems," "sanitary

systems," "water conservation," to the computer literature search

system developed by NASA, results in an output of a long list of

material related to this subject.

University of Wisconsin

Small Scale Waste Management Project

University of Wisconsin - Madison

College of Agriculture and Life Sciences

The University of Wisconsin has been very active in onsite

wastewater systems. Their finding is documented in numerous

publications entitled "Small Scale Waste Management Projects"

EPA Publication EPA-600/2 - 78 - 173

Management of Small Waste Flows

This publication prepared (under grant) by the University of

Wisconsin has valuable information on topics such as management,

requirements and research findings of onsite wastewater systems.

101
F.2 Conferences Related to Onsite Wastewater Systems

National Sanitation Foundation (NSF) Conference on Individual Onsite

Wastewater Systems. This conference took place in the fall of 1979

and is given annually in Ann Arbor, Michigan.

This gathering provides an excellent opportunity for a followup of the

ongoing research activities and information on experience gained with

new onsite wastewater technologies.

Environmental Protection Agency (EPA) Conference on Alternative and

Innovative Wastewater Systems. This conference periodically takes

place throughout the country mainly for informing professionals such

as contractors and legislators on the activity of EPA and its grant

programs. In addition, topics related to the state-of-the-art are

presented..

- Water Reuse Symposium. This bi-yearly symposium took place in the

spring of 1979 in Washington, D.C. Numerous topics were presented

on wastewater reclamation, resulting in three volumes of proceedings

with a total of 3,000 pages of printed material, from 155 papers.

F.3 Organizations Dealing with Onsite Wastewater Systems

The University of Wisconsin

This university is highly active in onsite wastewater systems, in

particular, in wastewater soil absorption systems and grey water

systems

The North Carolina State University

This university has been active in soil mechanics as applied to

wastewater soil absorption systems.

National Sanitation Foundation

This organization has been writing standards for wastewater systems

and testing systems which bear the NSF seal of approval, such as,

aerobic units and wastewater recirculation devices.

F.4 Manufacturers Marketing Wastewater Package Plants

Pure Cycle, Boulder, Colorado

This company manufactures individual wastewater recycling package

plants, with a degree of treatment of potable water quality.

102
Thetford Corporation, Ann Arbor, Michigan

This company manufactures wastewater recycling systems, with a degree of treatment acceptable for water reuse, for toilet flushing.

Aqua Saver, Baltimore, Maryland

This company manufactures recirculating grey water systems for

toilet reuse.

i

103
iU '

i

-

.

'
NBS-1 14A (REV. 9-78)

U.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET

1. PUBLICATION OR REPORT NO. NBSIR 81-22102.Gov'L Accession No,

4. TITLE AND SUBTITLE

ONSITE WASTEWATER SYSTEMS — Current Practices and

a Proposed Basis for Evaluation

5. Publication Date March 1981

6. Performing Organization Code

7. AUTHOR(S)

Fred Winter

8. Performing Organ. Report No.

9. PERFORMING ORGANIZATION NAME AND ADDRESS

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, DC 20234

10. Project/Task/Work Unit No. 742-1379

11. Contract/Grant No.

12. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street, city, st*te, ZIP)

Department of Housing and Urban Development

451 7th Street, SW

Washington, D.C. 20410

13. Type of Report & Period Covered Final

14. Sponsoring Agency Code

15. SUPPLEMENTARY NOTES

|

i Document describes a computer program; SF-185, FIPS Software Summary, is attached.

16. ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant bibliography or

literature survey, mention it here.)

A review of onsite wastewater systems and wastewater recirculation/reuse

devices based on the literature and field inspections of systems in actual

settings and usage is presented. Based upon the observations, an evaluation

basis for onsite wastewater systems is proposed. Criteria and requirements

for conducting and monitoring demonstration projects is presented. Wastewater

systems identified as potentials for demonstration projects are suggested.

Topics requiring further study are identified and recommended for specific

research

17. KEY WORDS (six to twelve entries ; alphabetical order; capitalize only the first letter of the first key word unless a proper name;

separated by semicolons)

Onsite wastewater systems; water conservation; wastewater disposal; wastewater

recirculation; wastewater reuse; wastewater treatment.

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