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Exhibit 4-4
METHODS FOR UPDATING LAND USE INFORMATION
• Interview the local building inspector to determine location
and type of new development
Technique: Request building inspector to draw boundaries of
nejj development, noting type of new development (residential3
commercial, industrial, etc.) density and changes in use.
Level of Detail: Variable, depending on map scale, accuracy
of additions.
Cost: Minimalj basically includes staff time for interviews,
redraw of added developed areas.
• Windshield survey conducted by consultant/planning office
staff
Technique: On-site, field inspection of newly-developed
areas. Requires back-up information on recent development
in the form of building permit. Can be used to locate newly-
developed parcels or to identify new uses. The field sheet
used to record this information can be tax assessor maps
which will enable acreage to be determined.
Level of Detail: Good
Cost: Moderate, basically includes staff time for survey,
map corrections at office.
• Recent aerial photos to identify extent of recently de-
veloped areas
Techniques: Purchase of aerial photos from public agency or
private mapping company. Developed areas and densities can
be delineated from aerials; uses must be checked through
other sources (either of the above).
Level of Detail: Depends on source of aerials. Enlargements
can be made if negatives are available.
Cost: Approximately $S/sheet, plus cost of mapping new
areas.
57
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straints on future development imposed by regulations and natural resources
limits on sensitive areas. Areas where wastewater needs may occur under present
zoning regulations can then be determined.
The existing zoning regulations may not be the only land use controls operative
in the planning area. The planner should also check the local subdivision
regulations, if they exist, and any specific State or local controls exercised
on proposed land development (e.g., areas of regional concern, protection of
sensitive areas, etc.). Any existing zoning plans or land use projections should
also be obtained.
Historic and archeological resources represent limited and non-renewable dis-
tricts, building, sites, structures, and objects having significant associations
with historic, architectural, archeological, or cultural events, persons, groups,
and social or artistic movements. The project planner, under procedure speci-
fied by EPA* has responsibility for identifying resources in the initial phase
of the facilities planning process. While the exact procedures vary from State
to State, the project planner is required to identify not only resources pres-
ently on the National Register but those potentially eligible for nomination.
The plan is submitted to the State Historic Preservation Office (SHPO) and the
Department of Interior for 'determination of any adverse effects. The historic
and archeological information is very critical in the impact assessment stage.
At a minimum, in the Community Profile Stage, the project planner should
determine the existing National Register sites. The SHPO will also provide at
this time guidance regarding other potential National Register sites.
4.2.2 NATURAL AND PHYSICAL FEATURES PROFILE
Data requirements and possible data sources for developing a Natural and Physi-
cal Features Profile are tabulated in Exhibit 4-5.
Climate
Climatological information is most useful to the engineer in terms of the con-
straints that it poses for certain technical options. For example, evapotrans-
poration systems, lagoons, land application, and air sludge drying are all
climate sensitive technologies.
Topography
Topographic information at 10 foot intervals as provided on the U.S.G.S. Quad-
drangle maps is sufficient at the Community Profile stage to determine drainage
basins, severe slope areas, and areas with significant undulating terrain.
Such information may be important in determining if wastewater collection is
economically feasible, and if so, what sewer technologies may be appropriate.
*"Construction Grants Program for Municipal Wastewater Treatment Works: Hand-
book of Procedures." EPA. 1976. p. IV-52.
58
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NATURAL AND PHYSICAL FEATURES
Exhibit 4-5
^S. DATA
^v SOURCE
DATA ^v
ELEMENT \.
CLIMATE |
Annual Precipitation
Mean Temperature
Temperature Ranges
Humidity
Prevailing Winds
Evaporation Potential-
Topography
V)
t-j
§5
Soils Limitation Maps
Interpretative Reports
Frost Depth
Wet lands
Flood Hazard Areas
SURFACE WATER— \
STREAMS/RIVERS \
SURFACE WATER— PONDS/LAKES
GROUNDWATER
Drainage Areas
Flow Characteristics
Water Quality Data
Existing Water Quality
Classificat ion
Existing Uses of Water
Drainage Area
Stream Sources
Elevation
Acreage
Mean Depth
Ownership
Water Quality Data
Existing Water Quality
Classification
Existing User of Water
Areal Extent of Aquifers
Groundwater Contours
Saturated Thickness* of
Aquifers
Transmissivity *
Existing Public Wells
Average Daily Drawdown
for Wells
Water Quality Data
National Weather
Service
•
•
•
•
•
•
Local Airports
Q
O
0
O
O
Local University
O
O
O
O
O
O
0
O
O
0
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•
•
•
•
•
•
•
•
•
•
•
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•
Soil Conservation
Service
•
•
•
•
O
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O
§
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X
CO
O
cva
•
•
•
•
•
•
•
O
State Division of
Water Pollution
Control
•
•
•
•
•
•
•
•
O
Local Tax Assessor
•
Local Water
Department
•
•
O
•
•
O
O
O
•
•
•
1U
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DATA USE
Alternative Screening
n
n
it
it
it
Screening- Defining Problems
it
it
Future Growth Constraint
Future Growth: Siting
Water Quality Impacts
n
it
n
»
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II
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ft
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it
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• INDICATES PREFERRED DATA SOURCE. ''HOT NECESSARY, BUT SHOULD BE
O INDICATES ALTERNATIVE DATA SOURCE. COLLECTED IF READILY AVAILABLE
59
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Soils
At the community profile stage a generalized soils map is essential for deter-
mining the potential suitability of land application and soil absorption sys-
tems. Soil maps and accompanying interpretive reports developed by the Soil
Conservation Service of the U.S. Department of Agriculture will provide a gen-
eralized method of assessing soil permeability and soil purification capa-
bilities. While more detailed site-specific soils information may be avail-
able from well driller logs and construction feasibility studies, at this stage
such site-specific information is not necessary. It would be useful, however,
to know how much data exists and where it can be obtained.
Wetlands
Information on wetlands is used in the facilities planning process to assess
areas unsuitable for development. The information will also be used in
assessing the environmental impacts of particular facilities. Basic wetlands
areas can usually be determined from the U.S.G.S. topographic maps. Seasonal
wetlands can be determined from the Soil Conservation Service (SCS) soils maps,
if available. More interpretive data on wetlands areas may be available from
local or State natural resource inventory reports.
Flood Hazard Areas
Flood hazard areas are important to the facility planner in the siting of faci-
lities and in determining areas that pose development constraints. They may
have been defined on the basis of the 100 year floodplain for the study com-
munity as part of a HUD flood insurance rate study. In the absence of such
data, the planner will probably have to deal with a variety of conflic-
ting sources, such as HUD preliminary "flood hazard maps" which in many cases
are based on arbitrary distances from water courses. There may also be a local
floodplain regulation in the zoning ordinance which restricts development in
a floodplain area, based on arbitrary topographic contour elevation. Addition-
al site specific flood elevation information may be available as needed in
facilities siting from U.S.G.S., the State Department of Transportation, or the
local highway department. HUD may also prepare flood hazard maps on request,
in some areas.
Surface Water
Information is needed to determine the potential impact of alternative disposal
options on any surface water which might receive treated wastewater. In many
cases, water quality constraints for certain water courses, such as streams and
rivers, will be given by waste load allocations developed by water quality
management agencies. The facility planner should nonetheless examine the basic
supporting stream data used in deriving those waste load allocations (drainage
areas, flow characteristics, water uses, water quality classifications, water
quality data, etc.) There may be cases where it will be necessary to go back
to the State water quality management agency to seek a modification of the
water quality constraints as identified in the 303(e) basin plans.
Explicit waste load allocations for ponds and lakes will probably not be avail-
able. Water quality impacts related to on-site systems, in particular, may be
60
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important issues for surface water impoundments. The planner should collect
readily available information at the Community Profile stage to begin estimating
these water quality constraints. Data needed on'ponds and lakes likely to re-
ceive treated wastewater would be similar to those listed above for streams and
rivers.
Groundwater
If on-site and land application systems are likely to be recommended in the
planning process, groundwater quality impact analysis will be an important part
of the overall selection of technologies. It is essential, then, to acquire
as much readily available groundwater data as possible in the Community Profile
Stage. It is of particular importance in this stage to identify existing and
potential water supply groundwater aquifers. This identification stage should
focus primarily on water table aquifers where there is greater potential for
water quality impact from on-site systems ; well records should be examined.
Ideally, information such as the following would be collected for each of the
water table aquifers in the study area.
• areal extent;
• saturated thickness;
• transmissivity;
• flow contours;
• existing water quality;
• depth to water table with seasonal variations;
• uses.
The principal data sources of groundwater information have been developed by
the U.S.G.S. and are presented in Exhibit 4-6.
The U.S.G.S. Hydrologic Atlases, if available, are the best and most comprehen-
sive sources of information. In many areas, they will not be available, how-
ever, and the other U.S.G.S. sources plus any other easily available information
should be used. Geology and hydrogeology departments of local universities may
have useful data about the aquifers. If additional data are required later
in the process, there may be unpublished data from many sources including
U.S.G.S., the local building inspector, the local water department, area well
drillers, and utility companies, as well as from state agencies.
4.2.3 EXISTING WASTEWATER DISPOSAL PROFILE
One of the main purposes of the Community Profile is to determine the types
and extent of existing wastewater disposal practices in the study area and to
collect information which will be used to determine, as best as possible, the
adequacy of these systems.
61
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Exhibit 4-6>
U.S. GEOLOGICAL SURVEY GROUNDWATER DATA SOURCES
U.S.G.S. Topographic Quadrangle Maps: These maps are import-
ant for groundwater information because they show surface
water elevations. In some areas, surface water will be the
surface expression of an unconfined aquifer.
U.S.G.S. Geologic Quadrangle Maps (Surficial Geology): These
maps depict the extent and location of various types of uncon-
solidated materials which occur surficially in an area. They
present a planimetric view of the various types of deposits
present at the surface of the study area. The planner should
locate materials, such as sand and gravel, on the map where
porosity and permeability are favorable to the occurrence and
availability of groundwater, to estimate the areal extent of
water table aquifers.
U.S.G.S. Basic Data Reports: Basic data reports are published
by the U.S.G.S. during their investigations of groundwater
resources for given locations and/or river drainage areas.
The reports include records and logs of selected wells, test
holes, and springs; and chemical analyses of water withdrawn
from these sources. The information is presented in tabulated
form recording the exploration number, location, owner, year
completed, evaluation, depth, and water table data.
U. S.G. S. Hydroloqic Atlases: Uydrologic Atlases are published
periodically by the U.S.G.S. to describe the availability of
groundwater, stream flow characteristics, and water quality.
A variety of maps and supportive texts may be provided. Those
most often prepared include a surficial materials map for the
area, a transmissivity map depicting the availability of water
bearing formations to conduct groundwater, maps showing the
locations and potential yields from aquifers (favorability
maps), the saturated thickness of unconsolidated materials,
groundwater quality maps, and charts detailing concentrations
of various elements in the water, plus surface water data, in-
cluding stream flow characteristics.
Water Consumption Data
Estimates of current and future wastewater flows are generally based on exis-
ting water use data. Water use information is also important in the assess-
ment of groundwater recharge impacts associated with households switching
from on-site systems to centralized surface discharge systems. In accordance
with the new Construction Grants regulations, water use information may be
developed by two different methods. In areas without water use or waste-
water flow data, standardized per capita figures shall be used to estimate
62
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residential consumption.* However, the preferred method is to fully document
water use when records are available. Water use records are likely to be avail-
able only for the public water service areas. Where good water consumption data
is not available or where there is a need to disaggregate total figures into
residential, commercial, and industrial categories the engineer will have to
make estimates.
On-Site Residential Wastewater Disposal
The Community Profile should determine the location of all on-site systems, as
well as any other easily obtainable information on system performance. Later,
in the Field Work stage of the methodology, additional data will be collected
if needed. A number of data sources for information on on-site system per-
formance are presented in Exhibit 4-7. During the Community Profile prepara-
tion the engineer should plan to interview members of the Board of Health or
the local sanitarian and examine any records relevant to problem areas. It may
be better to postpone any more detailed examination of installation and repair
records until the Field Work step so that the effort can be focussed on parti-
cular areas.
Existing Sewerage Facilities
Data collected in the category should be used to determine the types and extent
of existing public and private sewage facilities and, as best as possible, the
adequacy of these systems. Past performance records should be reviewed.
The engineer should interview not only the local official responsible for the
plant operations but also the plant operator. If it is detremined that any
treatment facility needs to be upgraded or expanded then operability should
be a primary concern. More detailed analyses such as independent sampling and
technical assistance to the operator are generally more appropriate during the
Field Work step. Exhibit 4-8 summarizes the types of information which should
be collected on public or private sewerage facilities.
4.2.4 EXISTING REGULATIONS AND INSTITUTIONS
Regulator}/ Constraints
The facilities planner operates primarily within procedures outlined by the
construction grants regulations. These are important to the process of doing
a facilities plan but consideration must be given to other regulatory con-
straints posed by Federal, State, and local laws and regulations that will
affect wastewater treatment in the area. In the Community Profile, the prin-
cipal regulatory constraints should be evaluated. These constraints will be
particularly important in screening alternatives in terms of sites and treat-
ment processes. If available, the constraints posed by an applicable 208 plan
must also be determined. Exhibit 4-9 suggests the type of major regulatory
constraints that should be examined in the Community Profile stage.
*The most current EPA recommended figures can be used as a starting point.
40CFR35. Appendix A, 8.6.
63
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Exhibit 4-7
Sources of On-Site Wastewater System Performance Data
0
Board of Health: Interview Board members and local sanitarian
0 Installation and Repair Records: If available the following
information about on-site systems can be useful in evaluating
performance.
0 installation date (from Board of Health records or
general age of housing)
0 sizing (from individual installation records)
0 test results made before installation
0 historical changes in standards (^combined with the age
of the system to give an indication of size and type)
0 records of systems repaired by order of the Board of
Health
0 Septage Disposal:
0 interview septic waste haulers in the area
0 how are haulers licensed and regulated?
0 where are disposal sites and are records kept of
the number of pumpings per week?
0 State Water Pollution Control Agency:
0 the state may have jurisdiction over large on-site
systems such as schools3 hospitals, and apartment
complexes and therefore may have more detailed
records
0 Water Quality Data: It may be possible from water quality
data to verify septic tank effluent leaching
64
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INITIAL DATA REQUIREMENTS FOR EXISTING PUBLIC
OR PRIVATE SEWERAGE FACILITIES
SEWERED SERVICE AREA
0 number of users
0 population served vs. sewer capacity
0 miles of sewer line
0 sewer map
0 type, age, and condition of sewers
TREATMENT FACILITIES
0 location
0 receiving water
0 age
0 average daily flows
0 peak flows
0 flow breakdown — residential/commercial/
industrial/institutional
0 treatment process
0 influent/effluent data
0 design treatment efficiencies
0 operational problems
SLUDGE TREATMENT/DISPOSAL
OPERATIONS AND MAINTENANCE STAFFING
REVENUES/EXPENDITURES
NPDES REQUIREMENTS
65
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PRELIMINARY REGULATOR! CONSTRAINTS SCREENING MATRIX
Exhibit 4-9
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Institutional Constraints
The design of realistic alternatives must include provisions for appropriate
management of the wastewater treatment facilities. The engineer must identify
which agency or agencies are responsible for various aspects of facilities
management in order to develop an implementable management program. Even if
the community presently has no sewered areas, there are still agencies which
have various functional responsibilities for the management of existing on-site
systems. In a community which has an existing wastewater management agency
the engineer should carefully review its organization and powers.
Exhibit 4-10 presents a summary Wastewater Management Agency Profile. This
summary can be used as an interview guide during the Community Profile step
when the engineer is collecting information on an existing agency. Later in
the process it may be necessary to plan for the creation of a new wastewater
management agency or to expand the powers of an existing one. The engineer
could then refer to this summary to insure that all the major institutional
aspects are considered.
Exhibit 4-11 presents a checklist developed to assist facilities planners
in analyzing the functional responsibilities for existing on-site waste-
water management. It is sometimes difficult to determine which parties
are responsible for the; various functions in on-site management because
of the split responsibility between the public and private sector. This check-
list can also be used in evaluating the management institutions for small
public or privately-owned neighborhood wastewater management systems. The
checklist presented in Exhibit 4-11 has been completed in order to illustrate
how it might be used. Again this checklist can be used by the engineer in
developing a management plan for on-site systems as part of a recommended al-
ternative. It is important that all aspects of on-site management from design
to financing be carefully accounted for in proposed management schemes.
67
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Exhibit 4-10
WASTEWATER MANAGEMENT AGENCY PROFILE
1. Organizational Basis
A. Strategy
B. Administrative
2. Date of Creation
3. Recent Jurisdictional Changes
4. Financing Authority/Sources
A. User Charges
B. Taxation
C. Government Appropriation
D. Grants
E. Loans
F. Other sources
5. Manpower
6. Budget Analysis
A. Major Line Items
B. Debt Structure
C. Trends
7. Organizational Structure
8. Data Collected
9. Relationship with State Water Pollution Control,
Environmental Health, or Other agencies
10. Intergovernmental arrangements with other local governments
(e.g., members of sewer districts)
11. Operating Constraints
A. Funding
B. Legal
C. Manpower
D. Other
12. Other responsibilities
68
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Exhibit 4-11
ON-SITE MANAGEMENT FUNCTIONAL RESPONSIBILITIES CHECKLIST
(A completed form is shown as an example)
DESIGN
PLANNING
INSTALLATION
OPERATION
MAINTENANCE
MONITORING
ALTERATION
FINANCING
MANAGEMENT ISSUE
Design Standards
Design Engineer Licensing
Site Feasibility Analysis
Plan Review
As-built Plan
Coordination with other
local boards
Installer Registration
Performance Bond
Excavation Inspection
Leaching Field — Fill
Inspection
Leaching Field — Grade
Inspection
Backfilling Inspection
Occupancy Permit
Public Education
Pumping
Pumper Registration
Recordkeeping
Surface Water Quality
Testina
Groundwater Quality Testing
Water Quality Monitoring
Repairs
Dwelling Unit Conversions/
Enlargements
Installation Fee
User Charge
Annual Appropriations
RESPONSIBILITY
Public
//
^
//
f
/-"
>/
f
f
^
/^
f^
^
f
Private
f
A^
f
/--
/^
//
/^
Not Done
^
//
^
f
f^
f
REQUIREMENTS/COMMENTS
State Sanitation Code requirements incorporated into County
Health Code; County has added requirements for alternating
fields
State requires that system designer be a licensed sanitary
engineer or pass state certification test
County requires deep pit observation holes in addition to
state mandated perc . test; also requires soils analysis for
certain sites; site analysis witnessed by county sanitarian
County sanitarian reviews final plans within 45 days as per
state sanitation code; systems >15,000 gpd in size
forwarded to District Environmental Health Office for review;
detailed plan requirements — copy enclosed
County requires as-built plan be filed with County Health
Department prior to occupancy permit issuance
Building inspector occupancy permit contingent upon County
Health Department ok; the building inspector also screens
dwelling unit changes for additional on-site system requirements
County requires installer to file a $2,000 performance bond
with County; refunded after satisfactory system operation for
365 days
County sanitarion inspects backfilling operation; 48 hour
notice required.
County Health Department must approve Building Inspector
occupancy permit at each change of ownership in a dwelling
unit.
Brochure on appropriate user habits for on-site systems
distributed at issuance of occupancy permit; also published
semi-annually in local newspaper
Occupany permit tied to a mandatory pumping of septic tank
once every three years; notice mailed to occupant at appro-
priate time; pumpout receipt required to be mailed back
within 60 days after pumping.
Private pumpers who serve homeowners are regulated by an
annual registration form; required to return a copy of each
form co county upon appropriate septage disposal
Through the occupancy permit renewal process and septage pump-
out receipts, County is tracking performance of all systems;
failures being correlated with user habits (through special
survey) as-built plans and soils
County Sanitarian monitors nitrate levels for public wells
that are in densely developed areas; water department conducts
water quality analvsis as per state requirements
County regulates all repairs as if they were new installations;
same regulatory process must be adhered to
County Building inspector notifies County Sanitarian of
dwelling unit changes for possible additional on-site
disposal requirements
County requires a $75 fee for reviewing design plans,
witnessing site feasibility analysis, and witnessing
installation
County levies a $25 user charge for the renewal of all
occupancy permits to cover administrative expenses
Health Department receives an annual appropriation from
the County general fund for department budget
69
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CHAPTER 5
TECHNICAL PROBLEM IDENTIFICATION
When the Community Profile has been drafted, wastewater management planning can
begin. The remaining planning effort has been broken down into two major parts:
the first (presented in this chapter) involves problem definition and identifi-
cation of technical options for each problem area; the second, (dealt with in
Chapter 6) involves generation and evaluation of wastewater management alterna-
tives for the community as a whole, and development of the recommended plan.
Thus, the analysis developed during this planning stage will be the foundation
from which the engineer will generate solutions to wastewater management prob-
lems. During this stage, the engineer must complete several tasks to advance
from a Community Profile based on secondary sources to the generation of alter-
native plans for the community. It is here that the greatest increase in effort
over the traditional facilities planning process is anticipated, since it is here
that additional information, not traditionally incorporated into the planning
process, will be generated and analyzed.
The tasks involved in Technical Problem Identification have been summarized in
a five step planning process. It will frequently be necessary to repeat
steps based on public input or as additional information is incorporated. The
proposed planning process is meant to be used as a guide, with the engineer
modifying it to fit the local situation. It may be practical to perform some
tasks simultaneously or in a different order. However, all the tasks are im-
portant for the fair evaluation of a range of alternative systems and therefore
should be conducted. The Board and State and Federal reviewers should be satis-
fied that careful consideration has been given to the points raised in this
methodology.
The five tasks are discussed in detail below with case study examples to illus-
trate the important points. Exhibit 5-1 schematically summarizes the planning
process presented in this chapter and suggests likely points of public review
and consequential revisions.
5.1 PROBLEM AREA IDENTIFICATION
Here the engineer synthesizes the material gathered during the previous stage
to define what is known and what is not known about wastewater management prob-
lems in the study area. The goal of this analysis is to identify problem areas
where the existing wastewater management facilities are inadequate for the pro-
jected development or incompatible with the overall plan. Thus, an area with
properly functioning on-site systems can still be defined as a problem area if
an extreme increase in density is expected over the twenty year planning period.
70
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Exhibit 5-1
TECHNICAL PROBLEM IDENTIFICATION
Problem Area Ident'
sf•lcat^on (5.1) \
Preliminary Technology Evaluation
for each Problem Area (5. 2)
^Public
T
Field Work Design and Data Collection (5. 3)
Technology Evaluation 2
•^Public j
T
•>y Problem Area (5.4)
input ^^ --------- -- •----.
'Selection of Technical Options
by Problem Area (5. 5)
71
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Exhibit 5-2
PROBLEM AREA IDENTIFICATION PROCESS
Are undeveloped lota currently
served by seuers?
Are existing faailities
adequate to serve
projected development?
Would conventional on-site systems
adequately serve projected
development?
Are on-site systems
compatible uith the
overall plan?
Is the projected
level of development
desirable?
Yes
problem
area
Three categories of information are used as criteria in identifying a problem
area. While the actual limits will vary from location to location, an evalua-
tion focused on the following topics will provide a good basis for problem
area identification:
• growth patterns and development potential;
• performance of existing wastewater facilities;
• potential sites for wastewater and residuals disposal.
Exhibit 5-2 summarizes the questions which should be answered during the prob-
lem area identification process. It is inevitable that there will be insuffi-
cient data about some areas to determine whether or not there is a wastewater
management problem. In these cases, additional data generated during the field
work step will be used to more accurately define problem areas. It is important
that the uncertainties be acknowledged and proposed data collection efforts be
presented to the public.
72
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5.1.1 GROWTH PATTERNS AND DEVELOPMENT POTENTIAL
One of the most critical issues facing the facilities planner is that of esti-
mating the size and location of future growth within the community. These
projections are necessary to insure that the planned facilities are adequate to
handle a reasonable amount of growth. Both the technical feasibility and the
desirability of future development must be assessed. Significant public invol-
vement will be necessary to insure that the growth implications of any plan are
acceptable to both the Board and the community.
The engineer, with the assistance of the Board, will make projections of growth
patterns and development potential based on information gathered from inter-
views, land use maps, zoning maps and by-laws, subdivision regulations, master
plans, and other sources. The projections can then be used in the identifica-
tion of problem areas and the Preliminary Technology Evaluation for each prob-
lem area. The growth and development assumptions and their possible wastewater
management ramifications can then be presented to the public. Based on the
reaction to the presentation, it is likely that the projections and relevant
technical evaluation will have to be revised.
The range of land use data sources varies widely and the number of potential
land use categories found in these sources is almost unlimited. There is also
the problem of identifying existing land uses and separating this information
from permitted land uses as established by zoning ordinances. For the purposes
of evaluating land development potential for a commmunity, existing information
may be too detailed or in an awkward format. One technique which may prove use-
ful in dealing with these problems is the classification by land use status. A
map can be developed summarizing data from various sources using the following
three categories:
• Developed Land is defined as all parcels which have already been
developed.
• Developable Land is defined as any parcel which may legally be de-
veloped. Physical characteristics of the site which may make devel-
opment prohibitively expensive are not of concern at this point.
Privately-owned land currently used for agriculture and recreation
should be included.
• Undevelopable Land includes all land which cannot be legally devel-
oped. This category includes all public or privately-owned land held
in fee simple specifically for the purpose of recreation or conserva-
tion. Power company and utility rights-of-way would also be consi-
dered undevelopable.
Of course, as with all procedures recommended here," the categories can be
modified to reflect the local conditions where required. For example, redevel-
opment may be occuring in some communities. Increased densities or conversion
from seasonal to year-round occupancy can have a significant impact on the per-
formance of existing wastewater facilities.
In each facilities plan, the engineer will have to decide how to distinguish
developed from developable areas since each vacant lot can seldom be identified.
73
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Whatever criteria the engineer selects to define "developable" should be
applied uniformly throughout the community. It is very likely that the cri-
teria will be modified durihg the categorization.
If the Construction Grants program in the State has a fixed policy on the fund-
ing of collector sewers, the engineer may wish to develop a map showing where
collectors might be grant eligible. If there is a set maximum distance between
connections, for example, the engineer could define an "ineligible" category to
cover those areas where development is so sparse that provision of traditional
gravity sewers would not be fundable. Certainly, the provision of this type of
information to the community early in the process would help them in establish-
ing their goals.
This land use status classification process was utilized in the case studies
and example maps are shown in Exhibit 5-3.
5.1.2 PERFORMANCE OF EXISTING FACILITIES
The objective of this analysis is to identify the areas of a community where
there are either existing or anticipated wastewater management problems so that
efforts can be focused on solving these problems. The identification of poten-
tial problems will allow the engineer and the community to take preventive steps.
This goal is achieved by determining where the performance of existing waste-
water management equipment is known to be adequate or inadequate, as well as
where there is insufficient information to make such a determination. This
evaluation should include consideration of the performance of privately-owned
individual on-site systems as well as centralized collection and treatment faci-
lities. Where the adequacy of performance is unknown, determinations should be
made as to what types of information would be needed to make a more detailed
evaluation. If it is clearly shown that the performance is inadequate, the data
should be reviewed to determine whether the failures are due to poor O&M or equip-
ment failures. In most cases, some additional research will be needed on confirmed
problem areas as well as on areas where the adequacy of performance is undetermined.
How does one evaluate performance in an undeveloped area where there are no
facilities? Here, the engineer should be concerned with expected performance
of wastewater facilities which would normally be installed under current codes,
given the development density presently permitted. In order to make this assess-
ment the engineer must determine the adequacy of the local code and its enforce-
ment. If the code and its enforcement are good, then the engineer does not have
to be concerned unless more development is desired than would be permitted by
the code. If the code or its enforcement are not adequate, regulatory and insti-
tutional changes should be evaluated as part of the planning process. Exhibit
5-4 illustrates how the performance of existing facilities was evaluated in the
Hilltown case study.
For each study area, criteria based on local conditions must be established to
identify on-site system failures. The percentage of the systems in an area
which must be failing before the area is considered a problem also needs to be
defined. Information on the magnitude and the distribution of on-site failures
is critical to the generation of alternative wastewater management schemes. The
dimensions and causes of failures can be used to determine whether the commu-
74
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Exhibit 5-3
GROWTH PATTERNS AND DEVELOPMENT POTENTIAL
The following maps illustrate how diverse the results of a develop-
ment potential analysis can be. In the case of Eilltown, a large
part of the community is institutionally undevelopable (state and
national forests and parks). Thus, the potential wastewater gener-
ating area is actually much smaller than the study area. Further,
there are very few large tracts of developable land, with most
growth projected for sites interspersed throughout the already par-
tially developed areas.
In contrast to this situation, Seatown has no areas.which are insti-
tutionally undevelopable (the utility right-of-way would qualify
except it is not within the district's jurisdiction)3 and there are
large tracts of undeveloped but developable land. Milltown presents
a more complex situation with several relatively developed centers
and a considerable amount of developable land.
In the case of Milltown and Hilltown traditional planning documents
such as plat maps, water district service maps, and county land use
maps were used extensively to develop these data. In the case of
Seatown, there were few traditional sources available. However, the
use of aerial photographs and a windshield survey proved sufficient.
If Seatown had been a more diverse community, the lack of land use
maps would have been a greater handicap* and funds would have been
included in the Grant Application to provide for collecting land use
data.
MILLTOWN
DEVELOPMENT POTENTIAL
WATER BODIES
UNDEVELOPABLE
DEVELOPED
DEVELOPABLE
75
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SEATOWN
DEVELOPMENT POTENTIAL
HJ DEVELOPED
^DEVELOPABLE
POWER PLANT
-------
Exhibit 5-4
MOTOWN
Existing Facilities
TRUNK SEWER
CREEK
SERVICE pi ON-SITE
AREA L-1 SYSTEM
Cited from Eir-soh & Co.
PERFORMANCE OF EXISTING FACILITIES
The map indicates which parts of Hilltown currently have access to
the sewer system and which parts are dependent on on-site waste-
water disposal.
A review of operation at the sewage treatment facility which has
been in operation since 1970 indicates that: the facility has had
no major equipment or operational problems, and the disposal ponds
have been functioning satisfactorily with no overflows. Based on
this review, it was determined that there are no wastewater manage-
ment problems within the sewered district.
The remainder of Water Districts 2 and 3 and all of District 1 are
dependent on on-site systems. The facilities planning process was
initiated by the State regulatory officials in anticipation of sur-
face and groundwater pollution problems as a result of extensive on-
site wastewater disposal. The State's action was based on the re-
sults of surface water testing over recent years which indicated an
77
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Exhibit 5-43 p. 5
increase in various pollutant indicators, threatening the water sup-
ply as well as ambient water quality.
The engineers reviewed the State data giving the Board the benefit
of an expert opinion. This review indicated that within the limits
of the data an increasing contamination of the stream was indicated.
However3 the data was limited enough to warrant a more detailed ex-
amination of the issue.
Conventional on-site systems in the area generally consist of a sep-
tic tank and leach field although a considerable number of the ex-
isting systems are quite old and likely to be substandard. In the
case of Eilltown the county—which has been responsible for over-
seeing the installation of on-site systems—only began keeping in-
stallation records in 1961. Since that time the Uniform Plumbing
Code (UPC) has been the basis for the local standards, although
good building practice would have warranted compliance with the UPC
even prior to the county's adoption of the code. A review indicates
that there were substantive changes in the UPC in both 1952 and
1963.
Using these milestones the engineers proceeded to analyze the mag-
nitude of the substandard system problem. Data on the number of
units in the area at various periods were taken from the census
tract information and from building permit records. Assumptions
were made in order to deal with conflicting data resources and a
summary table was developed. This analysis indicates that over 50%
of the existing systems are probably substandard based on current
codes, even assuming good installation and maintenance practice.
From the practical assumption of very questionable installtion con-
trol on the majority of old systems and nonexistent maintenance be-
fore failure, it seems quite reasonable to assume that a consider-
able amount of inadequately treated effluent is being recharged
from systems which appear from the surface to be functioning pro-
perly. This information will also be valuable in evaluating alter-
native on-site systems, by providing a basis for estimating the
number of anticipated replacements.
An effort was made to determine if any public agency had conduc-
ted a comprehensive ivestigation into septic tank performance and/
or maintenance in the study area. No such studies had been made
and there were no good sources of secondary information as to the
maintenance and failure rate.
Thus, based solely on the evaluation of the performance of existing
facilities the engineer has a good indication that the areas with ac-
cess to the existing sewer system were not problem areas while those
areas dependent on on-site treatment and disposal should all be
identified as potential problem areas. However, there were definite
indications that more research was needed before a final determi-
nation could be made.
78
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Exhibit 5-4, p. 3
SUMMARY OF PROBABLE SEPTIC TANK AND SUBSURFACE DISPOSAL SYSTEMS
45%-1148 Units range in age from 1-12 years and were built
to 1963 UPC standards or better.
16%-411 Units are older than 12 years of age, but were
probably constructed to 1952 UPC standards or
better (shorter leach line and smaller septic
tank standards than current regulations would
allow).
23%-600 Units constructed subsequent to 1952 UPC stan-
dards j but prior to County ordinance implemen-
tation.
16%-417 Units were probably constructed prior to 1950
without benefit of regulatory agency inspection.
These systems may be inadequate in design,
capacity} materials of construction, etc.
Total - 2576
nity can rely on on-site disposal in the future. If it is determined that on-
site systems can provide a viable option, it then must be determined how many
existing systems would have to be repaired or replaced. The level of detail
needed for a facilities plan must be carefully considered. At this point, the
engineer may only wish to estimate a percentage of the systems which need re-
placement and/or repairs.
It is important to advance to the next step in the process, the preliminary
evaluation of alternative by problem area. In an area where the performance of
on-site systems is inadequate or undetermined, the engineer should first de-
termine whether the continued use of on-site systems is likely. If con-
tinued dependence on on-site systems is unlikely, then further consideration of
the cause of failures is unnecessary. On the other hand, if there is a possi-
bility that an on-site management district might be a viable alternative, then
additional information on performance and the causes of failure may be required.
5.1.3 OPTIONS FOR WASTEWATER AND RESIDUALS DISPOSAL
The objective of this analysis is to locate potential disposal sites within the
community for wastewater effluents and residuals. This includes sites where on-
site disposal is appropriate as well as sites for centralized discharges. Exhibit
5-5 summarizes the analyses of wastewater and residuals disposal options for the
Seatown Case Study area. In some communities the number of discharge points will
be very limited, while in other communities there may be many locations suitable
for on-site disposal of effluent. Central business districts frequently have
severe limits on on-site disposal, making collection and transport the only
79
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Exhibit 5-5
OPTIONS FOR WASTEWATER AND RESIDUALS DISPOSAL
As there is no sewage treatment to generate sludge, residuals dis-
posal in Seatown currently involves transport of septage to a county
landfill. A disposal permit for stabilized, dried sludge is expec-
ted to be easy to obtain from the county. If large scale dependence
on septic tanks is to be continued, some form of septage stabiliza-
tion and dewatering prior to disposal or reuse would be recommended.
Disposal of wastewater effluents presents a greater problem. In the
coastal areas where there is relatively high-density development,
poor soil permeability, and a high groundwater table, the continued
use of individual soil absorption systems (SAS) for effluent dispo-
sal would be unsatisfactory. For both the developed coastal area
and the less developed central areas, the use of large scale land
application disposal techniques would not be practical because of
the high groundwater, poor soils and heavy rainfall. Similarly,
the region is climatically unsuited for the use of either individu-
al or community sized evaporation facilities for disposal. These
constraints eliminate all disposal options for the coastal problem
areas except surface water discharge. Individual SAS may be appro-
priate in the central problem areas if growth controls are imple-
mented.
In reviewing the logistical problems of surface water discharges,
there appear to be two basic options. One option would be to dis-
charge wastewater into the power plant cooling water canal where a
considerable degree of mixing can be achieved because of the large
flows. The second option would be to discharge directly to the Bay
using diffusion equipment. Preliminary review indicates that the
cost of constructing an off-shore discharge with equivalent mixing
and dilution as expected in the cooling canal would be very high.
Also, the lack of land for a treatment facility adjacent to the
coast is a factor against surface water discharge directly to the
bay.
logical options. In cases with very severe water quality constraints the en-
gineer may wish to consider evaporation ponds with no discharge.
In many small communities the disposal of properly stabilized residuals does
not present the problem it frequently does in larger metropolitan areas. How-
ever it is important for the engineer to consider which sludge and septage treat-
ment and disposal techniques are compatible with the disposal options available.
In most small communities landfilling of sludge and/or septage is common prac-
tice. However this practice is generally not acceptable unless the residuals
have been stabilized and dewatered. The engineer should carefully examine
current residuals disposal practices.
80
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When evaluating possible treatment and disposal sites, the engineer should con-
sider the characteristics achieved by various stabilization processes.*
Institutional issues can be very important when considering septage disposal
options. It may be best to transport septage to an existing wastewater treat-
ment plant which has sufficient capacity to accept such loads. This identifica-
tion of a disposal site outside of the jurisdiction may be very realistic for
some cases. Similarly it may be reasonable to establish regional septage treat-
ment centers.
If treated septage and/or sludge are to be disposed of locally, some form of
land application or landfill may be appropriate. If disposal sites are
limited, the engineer should focus on the selection of technologies which mini-
mize generation of residuals or effluent. Water conservation or waterless
toilets may help reduce effluent disposal problems. Treatment processes with
low sludge generation can help the residuals disposal issue.
5.2 PRELIMINARY TECHNOLOGY EVALUATION FOR EACH PROBLEM AREA
At this point in the planning process the engineers and the community have a
good idea of what the existing and potential wastewater management problems
are and where they are located. They also have an understanding of the exist-
ing facilities performance and other characteristics of the study area which
might influence the selection of the best management option.
Before embarking on the collection and analysis of original data, a preliminary
evaluation of technologies by problem areas is recommended. The objective is
to eliminate generic options which are clearly inappropriate—because they will not
work or are very costly—so that the data collection efforts can be directed
toward developing only that information needed to select among feasible tech-
nologies. In other words, the goal is to maximize the usefulness of expendi-
tures for original data collection.
The term "generic option" is used to describe a group of technologies which all
accomplish a task, although by various means. For example, pressure sewers,
vacuum sewers and gravity sewers all convey liquid waste from one point to an-
other, and therefore constitute a generic technological option of sewage trans-
port.
In order to complete a preliminary evaluation of the generic options for each
problem area, the engineer must have a good understanding of the options.
While engineering firms generally have a thorough understanding of conventional
gravity sewers and secondary treatment facilities, their understanding of other
technologies appropriate for small communities may be less complete, and some
guidance may be required.
*See the information on technologies in Appendix A.
81
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While the engineer would need detailed cost and design information to develop
criteria for selecting among the various technologies within a generic group,
there are characteristics common to the group which can be used to determine
whether any of the technolgies might be appropriate for a particular problem area.
For example, waterless toilets as a generic option would cover all closed system
toilets which do not generate sanitary sewage. These would include recycling
toilets, toilets using liquids other than water as the carriage medium, incin-
erating toilets, composting toilets, and perhaps others. The use of any of
these technologies would require retrofitting for existing structures, adaptation
on the part of the users to a "different" toilet, and some level of maintenance
and operation by the user. The engineer can use these common characteristics to
determine whether the generic technology should be examined in more detail or
eliminated early in the planning process.
The generic technology flow charts presented as Exhibits 5-6 and 5-7 summarize
various transport, treatment and disposal options for wastewater and residuals.
Brief descriptions of specific technologies are presented in Appendix A. In
general, representatives of manufacturers will be more than happy to provide
performance analyses, which may give valuable background information on the
less common technologies.
The decision tree presented in Exhibit 5-8 has been developed to assist the
engineer in systematically reviewing the data base assembled thus far to deter-
mine which technologies still appear reasonable and what additional information
would be required to reduce the number of options. By documenting why various
generic technologies are being eliminated at this stage, the engineer can ade-
quately demonstrate that the technologies have been considered without going
through a useless exercise of developing detailed cost-effectiveness analysis
for options which are clearly inappropriate.
The decision tree begins with the evaluation of the performance of existing
facilities. In the large majority of cases, the existing wastewater management
facilities in a small community problem area will be on-site, thus eliminating
the entire left hand side of the decision tree. In cases where there is a cen-
tralized system, the engineer would focus on the left hand side, eliminating
the questions regarding on-site systems. There may be some instances where a
single problem area is presently served by both on-site and centralized facili-
ties. In such a case the engineer would have to address both sides of the de-
cision tree. Exhibits 5-9 and 5-10 illustrate how the decision tree has been
used to screen alternative technologies for two different communities.
82
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Exhibit 5-6
GENERIC WASTEWATER TECHNOLOGIES FLOW CHART
RAW WASTEWATER
TRANSPORT
OFF-SITE
ON-SITE
ANAEROBIC
ON-SITE
AEROBIC
SEPTIC
EFFLUENT
TRANSPORT
OFF-SITE
PRIMARY TREATMENT
SOLIDS REMOVAL
/
ON-SITE
DISPOSAL
ON LAND
X
ON-SI1
FILT RAT IOts
FECTION Ats
TREATMENT
AND REUSE
SECONDARY TREATMENT
SOLIDS AND ORGANICS
REMOVAL
*
DISPOSAL TO
SURFACE WATER
DISPOSAL ON
LAND
v^ ^X inputs
•jif liquid residuals generated
I I generic technologies
"j^ solid residuals generated
I I generic disposal options
83
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Exhibit 5-7
GENERIC TECHNOLOGIES FLOW CHART
SOLID RESIDUALS
V ^
STABILIZATION
\
DEWATERING
LAND APPLICATION
DEh'ATERING
COMPOSTING
"fr
Landfill
inputs
I I generic technologies
I I generic disposal options
liquid residuals generated
Exhibit 5-8
DECISION TREE
PRELIMINARY TECHNOLOGY EVALUATION FOR EACH PROBLEM
Centralized
f Existing m
Facilities
Performing
Adequately
Performing
Inadequately
Performing
Inadequately
Performing
Adequately
Treatment
Inadequate
Correctable
by improved
O&M
-
\
Collection
Inadequate
Some structural
modification
required
Proper O & M
would correct
problem
Required „ ,
„. . , Replacement
Structural
Modifica-
tions
Transport
Modifications
on-site
Centralized
Neighborhood
Insufficient
Capacity
Inappropriate
Technology
New System
84
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Exhibit 5-5
SEATOWN
PROBLEM AREAS
PRELIMINARY TECHNICAL EVALUATION FOR SEATOWN PROBLEM AREAS
Based on their common characteristics, the six Seatown problem areas
can be grouped into two categories for the purposes of the prelimi-
nary technology evaluation. The coastal problem areas (1, 2, 3, and
4) are all densely populated and suffer current wastewater manage-
ment problems; the Central problem areas (5 and 6) are largely un-
populated but could anticipate wastewater management problems if
developed to higher densities.
The following is a summary of the Preliminary Technology Evaluation
for these two problem area categories using the decision tree. Since
there are no centralized collection and treatment facilities in
these problem areas, the left -hand side of the decision tree is eli-
minated in both cases.
The problem in the Coastal areas is well defined, and little field
work is necessary to evaluate alternatives.
In the Central areas, the major question is the demand for develop-
ment, and additional information is needed to determine the density
that could be adequately served by on-site systems.
85
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Exhibit 5-9, p. 2
SEATOWN COASTAL PROBLEM AREAS (1, 2, 33 & 4)
Centralized
p Existing
Facilities
Performing
Adequately
Performing
Inadequately
Correctable
by improved
OSM
Collection
Inadequate
-
On-site
Performing
Inadequately
Some structural
modification
requi red
Performing
Adequately
Proper O s M
would correct
problem
Transport
Modifications
on-site
Insufficient
Capacity
Centralized Neighborhood
Inappropriate
technology
Hew System
Rehab.
DECISION POINT
DATA DESIRED
A
TECHNOLOGIES ELIMINATED
Existing on-site Systems
Modified On-site Systems
Determine optimal scale for collection system
-identify potential disposal sites
-obtain accurate land use data
-receive input from community
REASON
-water quality analysis indicates contamination
with septic tank effluent
-all parties interviewed confirmed system fail-
ures.
-large number of illegal direct connections to
drainage ditches
-poor permeability} high water table, heavy
rainfall
-most existing units are on very small lots
-continued high density development is desired
86
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Exhibit 5-5, p. 3
SEATOWN CENTRAL PROBLEM AREAS (5 & 6)
Centralised
_ Existing
Facilities
Performing
Adequately
Performing
Inadequately
Treatment
Inadequate
\
Correctable Required
by improved Structural
OSM Modifica-
tions
\
Collection
Inadequate
S V
_ .~ . _\ .
»«**««•»«<* *«"»»>•
—•*• On-site
1
Performing
Inadequately
Some structural
modification
required
Performing
Adequately
Proper OSM
would correct
problem
Insufficient
Capacity
Transport
Modifications
on-site
Centralized Neighborhood
Inappropriate
Technology
New System Rehab.
DECISION POINT
DATA DESIRED
1 and 2
More specific information on performance needed
-conduct house to house survey in area
-interview septic haulers
Determine types, frequency and location of fail-
ures and feasibility of rehabilitation
-house to house survey
-plat maps
-soil tests
Determine the number of current and projected re-
habilitations and replacements
-analyze age of systems and sanitary codes in
effect at various times
-carefully review Board of Health enforcement
records for the area
-interview septage haulers
Determine optimal scale for collection system
-identify potential disposal sites
-obtain accurate land use data
-receive input from community
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Exhibit 5-10
PRELIMINARY TECHNOLOGY EVALUATION FOR A MID-WESTERN COMMUNITY
This example is based on a hypothetical midwestern farm community
where there have been a significant number of on-site failures,
both in the small town and on the farmsteads. The community con-
sists of approximately 50 farmsteads and a small cross-roads center
with about 15 residences and 10 commercial or municipal buildings.
The lot size in the center is generally less than 1/4 acre.
The community has been divided into two problem areas: the cen-
ter of town and the farmsteads. A moderate amount of growth is ex-
pected in the town, with very little growth expected in the out-
skirts. The preliminary technology evaluations for the problem areas
are summarized by the diagrams and charts.
A review of the Community Profile for the farmsteads indicates that
the on-site systems, which were generally installed SO to 50 years
ago, have had a poor performance record over the past ten years.
With the exception of a few systems which, have been completely replaced,
most of the farmsteads are depending on very old, substandard sys-
tems. It is unlikely that even if properly maintained the systems
could provide adequate service over a twenty year planning period.
Because of the long distances between farms, the engineer focussed
on on-site treatment and disposal. The number of systems to be re-
placed or rehabilitated could not be determined from the information
available.
However the analysis of soils data indicated two general conditions
so two typical leach fields could be designed. An estimate of how
many of each type of system would be used Was made from the soils
maps. Since most existing systems could not be expected to perform
adequately for the next twenty years, the engineers decided for
costing purposes to assume that new septic tanks and leach fields
would be installed at each farmstead.
For the purpose of the facilities planning process, therefore, it
was determined that field work to evaluate every system was not
warranted. The assumption of complete replacement is, of course,
extremely conservative and would have to be justified by supporting
data on system age and performance. Therefore, the engineer decided
to carefully examine the Board of Health files and interview the
local septage haulers. If the result of this field work indicated
the assumption to be inaccurate, then some revision would be re-
quired.
The preliminary evaluation of the technical options for the center
of town revealed that the lots are too small to permit extensive
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Exhibit 5-10, p. 2
DECISION TREE
FARMSTEAD PROBLEM AREA
Perforoiing
Adequately
Centralised "** ""
\
Existing __
Facilities
Performing
Inadequately
Performing
Inadequately
On-site
' \
ing • Psrforaing
Treatnent
,Inadequate
\
Correctable Required
by inproved Structural
OSM Modifica-
tions
Collection
Inadequate
Replacement
Some structural
modification
required
\
Adequately
Proper 0 « H
would correct
problea
Centralized
Insufficient
Capacity
Inappropriate
Technology
*|«ft»pOIt Moairications
~S \ on-site
/•' \ /\
liWMJ neighborhood / 1 \
X \
New System Rehab.
DECISION POINT
ADDITIONAL INFORMATION NEEDED
Confirm assumption that most systems are very old,
and few would be adequate for the 20 year plan-
ning period.
OPTIONS ELIMINATED
REASON
Continued use of
Existing Systems
O&M of Exi-sting On-site
Transport of Effluent
-Consensus of regulators, Board of Health
-Failures are too serious and frequent, and sys-
tems are old, substandard and over loaded
-Distances between units is too large
replacement or rehabilitation of on-site disposal systems. This
fact combined with land availability makes the use of community
leach fields the preferred option if continued use of septic tanks
is anticipated. It was therefore determined that additional infor-
mation on the performance of individual leach field was not re-
quired and that a conservative approach calling for new septic
tanks would be taken for cost estimating purposes.
Thus the focus of additional data collection should be on the suita-
bility of possible community leach field sites. Soil testing and
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Exhibit 5-10, p. 3
DECISION TREE
CENTER OF TOM PROBLEM AREA
Centralised "*-
_Existing
" Facilities
• On-site
Performing
Adequately
Performing
Inadequately
Treatment
Inadequate
Correctable
by improved
OSM
\
Col]
ttOK ,
^ ., / \
JUSCfUirfiQ ^k *_
^^^ . _ RCpiflCCBteflt R
-------
5.3 FIELD WORK DESIGN AND DATA COLLECTION
Once the preliminary technology evaluation for each problem area has been com-
pleted, the engineer should have a good idea of what information will be needed
to narrow the range of options and to develop the plans necessary for cost-
effectiveness analysis. Additional information will inevitably be needed to
complete a cost-effectiveness analysis of integrated programs to serve the en-
tire community. Therefore, Field Work to generate the specific information re-
quired consists of original data collection, interviewing and retrieval of ad-
ditional secondary source data.
While every facilities planning area presents a unique set of problems for data
collection, there are some guidelines which are useful to remember. A Field
Work plan should be developed to make the most of limited resources. On the
basis of the preliminary evaluation, the engineer should determine what infor-
mation is really needed. A list of potential sources and an organized plan of
data collection should be developed to reduce the number of repeat visits and
overall costs.
The possibility of retaining expert opinions should be examined at this point
since the engineer can clearly define what tasks such consultants could com-
plete. While preliminary budgets for expert consultants must be submitted with
the planning grant application, the actual scopes of work to be done by consul-
tants should only be developed at the point where the project engineer knows
what information would be most useful. Because it is not always possible to
predict the level of uncertainty, modifications to the planning budget may be
required.
The engineer should evaluate the performance of existing centralized facilities
using both secondary sources and original data collection. If current treat-
ment plants are not meeting their discharge permit requirements, it is import-
ant to find out why. For example, if the problem is only the management of a
well-designed and correctly-sized system, this can be corrected with training,
technical assistance, and other operations support, without any requirement for
large scale upgrading or modification. On the other hand, if the problem is
poor design, some modification of the capital equipment may be required. If
the problem is simply insufficient treatment capability or hydraulic overload,
then upgrading and expansion may be necessary.
The engineer should work with the operators of any existing plants and obtain
information on the variation in wasteloads over time, effluent quality, opera-
ting procedures and so forth. Any unusual operating problems should be noted,
so that they can be considered in the generation of alternatives and the select-
ion of systems.
Exhibit 5-11 uses the Hilltown case study to illustrate the field work conduc-
ted to evaluate the performance of existing on-site systems. The techniques
illustrated in this example combined with the analyses of the same area during
Problem Area Identification (Exhibit 5-4) provide some good ideas for data col-
lection and analysis on this difficult question.
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Exhibit 5-11
HILLTOWN - ON-SITE SYSTEMS
Based on the Preliminary Technology Evaluation of the problem areas
in Hilltown currently dependent on on-site systems, it was deter-
mined that the continued use of such systems might be desirable.
However additional information on current system performance and ex-
pected performance of future systems was needed before a final deci-
sion could be made. In addition the Board wanted to confirm allega-
tions that septic tank effluents were contaminating the stream and
threatening the water supply.
The town's engineer initiated a surface water sampling program which
was carried out during the peak population months of June and July.
The results of the program confirmed the conclusions reached by
the State. Further, the results indicated definite presence of syn-
thetic detergents in the streams. This supported the assumption
that the contaminants are man-generated and not the result of inter-
mittent animal defecation in the surface waters.
Records for septage disposed at the local landfill revealed that a
large number of truck loads had been dumped. However, without ad-
ditional information it was difficult to convert the figure for
number of truck loads dumped at the landfill to a number of septic
tanks pumped, or to determine whether the pumping was simply a
maintenance procedure or the result of septic system failure. To
make these judgments the engineers interviewed the major septage
haulers. These interviews revealed that virtually all pumpings were
a result of malfunctions in the systems such as backed-up building
sewers, blocked leach lines or septic tank, surfacing effluent, or
malodorous condition.
On the basis of this information, the data on truckloads trans-
ferred to the "landfill was used to estimate that 9 to 10% of the
existing systems suffer failures each year. The haulers indicated
that one of the problems was tree root intrusion, which is more
serious in systems serving seasonal dewellings. Some seasonal re-
sidents have all but given up on clogged leach fields and used
their septic tanks as holding tanks; several systems are pumped
more than once per year.
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Several technologies for the detection of septic tank failures are currently
being tested. Among these are remote sensing by aerial photography* which
detects areas where there is surface breakout of 'septic tank effluent and sep-
tic detection along shorelines** which detects leaching of effluents into sur-
face water bodies. If there is a question as to whether existing systems are
performing adequately or it is important to locate which specific systems are
failing, the engineer may wish to investigate the use of such a technology.
However, such advanced methods should only be employed in situations where the
continued use of existing on-site systems is seriously contemplated. Frequent-
ly this level of detail would be more appropriate in the Step II Design.
Interviewing with both agencies and users can provide important original data
on the performance of on-site systems. The Management Agency Profile presented
in Exhibit 4-10 outlines the types of information about an agency the inter-
viewer should request. It may be valuable to survey some of the residents and
commercial users, particularly in areas where performance problems are not well
defined and continued use of on-site systems is contemplated. Experience with
mail surveys has indicated that the random nature of responses makes the re-
sults very difficult to use in actual facilities planning, though potentially
useful in gaining a sense of the community preferences. Therefore, it is rec-
ommended that surveys be used in areas where door-to-door personal interview-
ing is logistically feasible. Even with the use of volunteer organizations as
interviewers, a community-wide survey would only be recommended in very small com-
munities. An example Residential Survey Form is presented in Exhibit 5-12.
Additional information about existing water quality or potential water quality
impacts of various technical options may also be desired. Many engineering
firms have sufficient in-house expertise to design a surface water sampling
program and to analyze the results. Surface water analysis can be used, as in
the Hilltown example, to confirm contamination by septic tank effluent. How-
ever, firms frequently do not have this type of expertise in groundwater analy-
sis, where the number of variables is even greater. When it is necessary to
assess the groundwater water quality impacts of land application systems, the
engineer should first determine if groundwater is a serious issue. Clearly,
water table aquifers which are used for drinking water supply present the most
critical groundwater resource to be protected. It is similarly important to
protect aquifers which feed surface water bodies which are sensitive to nutrient
contamination. Groundwater quality and flow analysis including well sampling,
development of flow nets and dye testing may be warranted. Particular concern
should be placed on areas where homes have both private wells and septic tanks,
areas around public wells and areas near sensitive surface water bodies.
As stated above, each community will possess a unique set of circumstances for
field work design. Therefore, the engineer must carefully develop a field
work plan before initiating original data collection. By planning the field
work in advance, it should be possible to maximize the returns from data col-
lection.
*Environmental Photographic Interpretation Center.
**"Septic Leachate Detection - A Technical Break Through for Shoreline Lake
System Performance Evaluation", W.B. Kerfoot
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Exhibit 5-12 REQUEST FOR INFORMATION ON WASTEWATER DISPOSAL
The information on this form will be strictly confidential. Specific information from this form will be released for
public review.
ADDRESS:
1. WHAT TYPE OF WASTEWATER DISPOSAL SYSTEM DO YOU HAVE? septic tank/leaching field cesspool
discharge to surface water other (location of discharge:
2. WHEN WAS THE SYSTEM INSTALLED?
3. RAVE YOU HAD ANY PROBLEMS WITH YOUR UASTEUATER DISPOSAL SYSTEM? yes
4. PLEASE TELL ME THE TYPES OF PROBLEM THAT BEST DESCRIBE OH DESCRIBED YOUR SITUATION. (CHECK MORE THAN ONE IF
NECESSARY. )
slow drainage in sink and other water using appliance odors outside
toilet sometimes backs-up liquid is visible an the ground surface Other
5. HOW OFTEN DO YOU HAVE PROBLEMS WITH YOUR SYSTEM?
weekly monthly frequently other
6. IN WHAT SEASONS DO YOU GENERALLY HAVE PROBLEMS? (CHECK MORE THAN ONE IF APPROPRIATE.)
spring summer fall winter
7. DO YOU HAVE PROBLEMS AFTER PERIODS OF FREQUENT OR HEAVY RAINFALL? yes no
8. HOW HAVE YOU COPED WITH THE PROBLEMS?
a. pumping * HOW OFTEN? weekly monthly winter
t WHAT IS THE COST OF PUMPING?
b. restricting water use » HOW?
repairing system 1 » PLEASE DESCRIBE
d. other
(IF NO REPAIRS, SKIP TO QUESTION 10.)
9. IF YOU HAD YOVR SYSTEM REPAIRED, CAN YOU PLEASE TELL ME
• WHEN HAS IT DONE? • HOW MUCH DID IT COST?
• WHAT WAS DONE?
WHO DID IT?
* HAVE YOU HAD MORE THAN ONE MAJOR REPAIR DONE ON YOUR SYSTEM? Yes No
IF YES, DESCRIBE
10. HOW OFTEN DO YOU HAVE YOUR SYSTEM PUMPED?
once a year once every two years once every three years
11. HOW MUCH DOES IT COST TO HAVE YOUR SYSTEM PUMPED?
12. WHAT WATER USING APPLIANCES DO YOU HAVE? dishwasher garbage disposal
washing machine connected to the disposal system washing machine not connected to the disposal system
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Exhibit 5-12, p. 2
REQUEST FOR INFORMATION ON WASTEWATER DISPOSAL
IS. WHEN WAS YOUR HOUSE BUILT?
14. WHAT IS THE APPROXIMATE SIZE OF WUR HOUSE LOT?
15. HOW HANI PEOPLE LIVE IN WUR HOUSEHOLD? ages: 0-12 22-18 18 & over
16. HHEN IS WUR HOUSE OCCUPIED? year round seasonally month occupied
17. DO ANY OF WUR NEIGHBORS ON YOUR STREET HAVE PROBLEMS WITH WASTEWATER DISPOSAL? yes
• mi DOES IT APPEAR THERE IS A PROBLEM?
liquid is visible cm the ground surface odor frequent pumping
other (explain) ________„________^^__—^^______^_____________^__________
18. DO YOU FERTILIZE YOUR LAWN ANNUALLY? Yes No
• APPROXIMATELY HOW MANY POUNDS OF FERTILIZER DO YOU APPLY?
19. DO YOU HAVE ANY COMMENT YOU WOULD LIKE TO MAKE?
THASK YOU FOR YOUR TIME. THERE WILL BE PUBLIC MEETINGS ON WASTEWATER PLANNING ANNOUNCTED IN
. I HOPE YOU HAVE THE OPPORTUNITY TO ATTEND.
5.4 TECHNOLOGY EVALUATION BY PROBLEM AREA
This is an iterative step where the engineer takes the information developed
during the Field Work and applies it to the task of further narrowing the
range of technical options for the individual problem areas. The objective is
to reduce the number of options to make the development of community wide con-
cepts an easier task. Thus, where the results of Field Work indicate that cer-
tain options are not feasible, the range can be narrowed. Where field work
has provided additional information but that information is not sufficient for
selecting among alternatives, the data can be used in performing more detailed
cost-effectiveness analysis which would then be indicated.
5.5 ACCEPTABLE GENERIC OPTIONS BY PROBLEiM AREA
This step involves public review of the Technology Evaluation. It is important
that public acceptability of various technical alternatives be assessed before
detailed cost-effectiveness analysis is completed. It makes little sense to
prove that a technology would be most cost-effective if the community will not
accept it. This step reflects the importance of an active public participation
effort at this point in the planning process.
It is likely that a public meeting will not generate sufficient interest in
the community to insure that all questions are raised. The engineer should be
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prepared to spend the time necessary to generate as much interest in the plan-
ning process as possible. Press releases should be prepared regularly for the
local paper so that the various options under consideration are introduced be-
fore any public meeting rather than reported after the fact. In larger commu-
nities a citizens advisory committee may be used. The members of this group
can help disseminate information about the planning process. It may be possible
to enlist the services of non-profit community organizations such as the Scouts
or a high school civics classto help distribute leaflets and generate interest
in the planning process.
In any case, it is unlikely that the community will be unanimously in favor of
any single proposal. There will always be divergent points of view, particularly
on controversial issues such as the provision of services to only a portion of
the community or the impacts on growth. In preparing documents for presentation
to the public, the engineer should be careful to address the questions most like-
ly to be raised by the residential user:
• What will it cost?
• Will this mean more development in my neighborhood?
• How much development?
• Will I be subsidizing the people in the center of town (or vice versa)?
Clearly, some of these questions are appropriate early in the problem area iden-
tification step while others would be more appropriately addressed in the anal-
ysis of overall programs for the entire community. However, it is likely that
they will all be raised at this point and the engineer should be prepared to
either answer the questions or explain why they cannot be answered as yet.
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CHAPTER 6
GENERATION AND EVALUATION OF SYSTEMS FOR THE COMMUNITY AS A WHOLE
The previous two chapters have presented methods for identifying wastewater
management problems and devising ways to solve local problems using new facili-
ties or non-structural controls. The goal of this stage of the planning is to
integrate those solutions for the individual problem areas into community-wide
systems which will effectively abate the pollution problem. Moreover, this
stage must evaluate these proposed community-wide systems, so that the best can
be chosen for implementation.
This is a difficult problem, and it is worthwhile to consider for a moment how
difficult it might be. In Milltown, for example, there were 10 problem areas.
Three to five generic technologies were developed for each problem area. By
choosing combinations of these technologies for the problem areas, it would be
easy to generate perhaps 40 community-wide systems for evaluation (and the num-
ber of possibilities is much larger). These possibilities would not even in-
clude such details as the type of transport system or treatment plant to be
used, or whether land disposal should be surface or subsurface. Considera-
tion of collection, treatment, and disposal technologies would at least triple
the total, so that it would conceivably be necessary to prepare and evaluate
detailed plans for 100 or more different systems.
Obviously, this is impossible. More important, most of these combinations would
be unreasonable and could never be implemented. Therefore, a procedure is
needed which will reduce these hundreds of options to a few, with detailed cost-
effective and environmental evaluations performed only on those few. The
screening of options done at each point must be consistent with the information
available about them. Rough estimates should be used in the initial screening,
with more detailed information developed when needed. Public participation
will be important throughout.
Several evaluation criteria have to be considered, including:
• overall cost-effectiveness;
• local costs for all parts of the system;
• distribution of local costs (who pays and who benefits);
• dependability and risk;
• public acceptability;
• direct environmental impacts;
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• operability;
• land use and development impacts, with consideration for what
these potential changes would mean to the community and the
environment;
• other socio-economic impacts.
There are five major decisions which must be made, and the remainder of this
chapter is organized around those five decision points. They are:
• initial decision on system structure and discharge points for
all wastes (6.2);
• a decision on the boundaries for all sewer service areas, and on
the placement of projected growth (6.3);
• a decision on the technologies to be used for each area (6.4);
• decisions on management procedures, cost allocation, and
staging (6.5);
• selection of the final recommended plan (6.6).
Exhibit 6-1 shows the organization in a flow chart. In addition, Sec-
tion 6.1 describes a number of the critical issues which arise in evaluating
projects, and which must be considered.
6.1 EVALUATION ISSUES
The basic question is "which mix of options for the community should be imple-
mented?" Under each of the proposals, all wastewater must be handled in
an acceptable and environmentally sound manner. Therefore, according to EPA
regulations, each must be evaluated for its cost-effectiveness, as well as its
other impacts—primarily environmental and socio-economic—on the community,
with a goal of selecting the best community-wide system option. To do this, it
is necessary to know how to evaluate the various options. The major factors
were listed in the introduction to the chapter, but care is required if each is
to be considered correctly.
It is a basic assumption that all the proposed systems must provice acceptable
service to the residents and firms of the community, even though the method
varies. In other words, the wastewater must be handled in an "environmentally
sound manner" and one that is acceptable to the community. Any systems which
do not meet such requirements should not be considered further. Public parti-
cipation is important to assess acceptance of various technologies.
The residents must pay both the public and private costs of the system. For a
fair evaluation, then, we must be concerned with the full costs of the system
to all users. Cost-effectiveness from the national viewpoint is the key meas-
ure for receiving EPA grants, but local costs are also important. Care must
be taken to avoid analyzing incomplete systems, where the costs are not com-
parable across technologies.
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Exhibit 6-1
GENERATION AND EVALUATION OF COMMUNITY SYSTEMS
System Structure and
Discharge Points (6.2)
Defining Approximate Boundaries
for Sewering Service Areas (6. 3)
Technologies Selection (6.4)
Management3 Cost Allocation
and Detailed Evaluation (6. 5)
Final Recommendations (6. 6)
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For example, one of the easiest ways to bias an analysis against on-site alter-
natives is to consider the full on-site system in the costing, but to start
counting sewer costs at the street. The house connection can be extremely ex-
pensive in some cases, and should be considered as part of the wastewater man-
agement system.
Another way of analyzing incomplete systems is to analyze one system (i.e., a
sewer) for its service area, while analyzing another (e.g., a septic tank main-
tenance program).for the community as a whole. The latter may serve more sites,
and thus incur higher costs. It is our view that management is required for the
community as a whole, and that all costs should be included in comparative
analysis, even such things as an individual's cost for septic tank pumping. By
requiring that all systems be evaluated for the entire area, the: costs can be
consistently compared and will not be biased towards the more limited options.
Design Lives: The salvage value evaluations, and the other portions of the
cost analysis, require that design lives be estimated for the various techno-
logical options. For on-site systems, however, these design lives are diffi-
cult to estimate, since there is limited experience with them in-place. It is
assumed here that 20 years is the design life of new on-site systems.
Therefore, a septic tank—soil absorption system installed under the plan would
be assumed to last 20 years for the cost-effectiveness analysis. Similarly,
in an area served with existing septic tanks, if 2% currently required major
rehabilitation and new leaching fields each year, it is assumed that 2%
would require rehabilitation each year over the design period. Detailed
cohort analyses for existing systems may also be done, if past changes in
in standards may have affected design life.
Certain technologies or components have known design lives which are relatively
short, for example, the pumps for pressure sewers. It is assumed, though,
that the piping for pressure sewers will last as long as the pipes for
conventional sewers. Where there is limited other information, then, the
engineer should attempt to make reasonable assumptions about design lives and
point out these assumptions in a table for comment by reviewers in the community,
State agencies and EPA.
Time-staging; Delaying (and discounting) future investments can reduce the cost
of systems. This is desirable in many cases; for example, in Milltown, there
was a trailer park with subsurface disposal on very small lots. In the problem
area identification phase, it became apparent that it would probably be only a
matter of time before failures became common in this area, and systems would
need to be installed, so the community systems include suggestions for this
area.
However, no action is required now, and it may not be necessary to do anything
for 10 years or so. Therefore, this phase of the overall project is suggested
for later implementation.
Phasing of projects is suggested for study in the EPA Cost-Effectiveness Analysis
Guidelines. However, it can bring about some problems in evaluation, particu-
larly when different systems are staged differently. Assume, for example, that
the options are to build a collection system and treatment plant, or to set-up
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an on-site management district. Also assume (for the moment) that the on-site
district is slightly cheaper. By phasing the collection system, and assuming
that the areas to be served would require nothing while they awaited sewer con-
struction, it might be possible to make the sewer system appear less expensive.
This is just another example of incomplete analysis. Actually, the areas which
were planned to receive sewers in 10 or 15 years would need some sort of man-
agement system in the interim, and ignoring the costs of such a system would
simply bias the analysis in favor of sewers. The complete systems to be compared
should not only provide service to all households in the community, but provide
such service for the full 20-year planning period. Staging plans can save a
great deal of money, but they do not make problems go away, and the costs of
meeting those problems while waiting for the staged investment should be
considered.
Conflicts Between Cost-Effectiveness and Community Preferences; Standard pro-
cedure has been to provide grant assistance only for the most cost-effective
alternative, except in very special cases. With the implementation of the
Clean Water Act, this procedure has been modified in two ways: in many cases,
the community can build excess capacity it desires without losing its Federal
grant; and, Alternative and Innovative technologies can be selected if they
are no more than 15% more costly than conventional systems.
However, if a community prefers to fund a land application system (qualifying
as Alternative) that is 20%, or even 16%, more expensive than a traditional
system, it will not be able to receive a grant for the project. It would have
to either build the project selected by EPA, or fund the land application sys-
tem locally, perhaps with some State assistance. There is no mechanism under
the regulations for the EPA to give a grant of less than 75% for projects
which are not the most cost-effective even if the community is willing to
pay the difference.
This sort of conflict is likely to occur in small communities, particularly
when Alternative and Innovative technologies are being evaluated; it is likely
to lead to some problems in applying the regulations.
Distribution of Costs: The distribution of costs may be important, parti-
cularly in the final details of the analysis. For example, it may make a big
difference whether repairs and rehabilitation of on-site systems are the res-
ponsibility of the management district, or of the individual householder. Con-
sider the case of a community which is partly served by sewers and treat-
ment plant, and partly by on-site systems with a management district. The com-
munity could lump all costs together and charge a uniform user fee. Alter-
natively, it could charge those in the sewer service areas their portion of the
total costs, and those in the on-site area their portion. Issues related to
distribution of costs are likely to be extremely significant politically.
Environmental Impacts; These must be considered, and there are two types of
direct impacts that are likely to be of interest. One is the direct environ-
mental impacts of the facilities, which are probably small. All facilities
are assumed to meet water quality standards, assuming proper design,construc-
tion, and operation so the comparisons will be between facilities which exceed
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standards by different amounts, or which discharge to different water bodies.
Some consideration of aerosols, odors, facility esthetics, and the like may be
required. The second type of direct impact consists of short-term problems
arising from construction, and these are also likely to be insignificant.
More important than the direct impacts, though, are the indirect ones, which re-
quire some measure of land use change. If wastewater facilities change the
capacity of an undeveloped area from 100 new homes before the sewer to 500 after
construction, this should be identified. The same is true if the shift is from
100 to 50. Such shifts can affect land values, of course, but they can also
affect future growth patterns, and the demands for other services. Impacts on
land use and development should be estimated as part of the screening process,
and stated as part of the final evaluation and recommendations. This is an
area where public participation is likely to be of critical importance. Land
use change may be the source of all the major environmental and socio-economic
impacts in some areas, and needs to be considered throughout the evaluation.
6.2 SYSTEM STRUCTURE AND DISCHARGE POINTS
In most small communities, there are relatively few options for where to dis-
charge the waste. In two of the three case studies, for example, the discharge
points were fixed, and the major issue was the extent of sewering (a question
addressed in detail in Section 6.3). In communities such as these, where
natural conditions and existing constraints severely limit the disposal options,
this stage of the evaluation can, in fact, be eliminated.
On the other hand, some communities are as complicated as the Milltown case pre-
sented in Exhibit 6-2. Several different choices may exist for each problem
area, ranging from waterless toilets and graywater discharge,to connection to
a large-scale sewer system with downstream discharge. The first step in such
cases is to identify a range of possible alternatives, using the results of the
previous chapter. The presentation does not need to include all combinations;
instead, it describes a limited set of choices which show certain characteris-
tics (e.g., maximum use of on-site system; maximum use of group subsurface dis-
posal; maximum extent of sewering).
These system concepts can be defined in a number of ways. However, it is like-
ly that the major evaluation factors can easily be derived from public input.
For example, one natural dimension along which to design such concepts is the
level of centralization, which can be translated into the extent of sewering of
problem areas. Several concepts can be developed which show different amounts
of centralization, with all such concepts solving the problems in each area.
Another dimension of interest may be the ability of the system to serve new
growth, which is likely to be a concern in many communities. Various concepts
can be prepared which will affect the potential for new development,
and these can be presented to the Board for review. In any case, each
concept should be defined to include:
• an acceptable generic option for each problem area;
• any necessary management or facilities for non-problem areas;
• disposal sites for all effluents and residuals.
102
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Exhibit 6-2 , p. 1
SYSTEM CONCEPTS FOR MILLTOWN
Milltown is an extremely complicated small community for wastewater
management, with 10 district problem areas and a large number of
non-problem areas (largely undeveloped). In generating community-
wide alternatives, several options for the individual problem areas
were developed using the methods of Chapters 4 and 5. These were
arrayed as shown in the first table. Solutions we-re then chosen
which would make the maximum use of on-site sysetms, and which would
maximize centralized treatment and disposal, as well as four inter-
mediate concepts, also shown in the tables and maps.
Rough costs were developed for each system. These showed that
concept #6 was much more expensive than the others.
A map was prepared showing the areas where excess capacity in the
centralized system would be likely to have the strongest effect on
growth, by highlighting the undeveloped areas close to the proposed
trunk lines. Much of the work in this stage was directed at deter-
mining whether the potential discharge sites for the individual
problem areas were actually available, and acceptable. Sites for
subsurface disposal were found for all the suggested locations, but
no land application sites could be found for problem area #1, Since
the costs of treatment and stream discharge for that problem area
did not appear to be extreme, the land application option was elim-
inated there.
The results of this stage can be summarized as follows:
• concept #1, with its dependence on retrofit of on-site
systems, was unacceptable to the community;
0 concept #6, maximum sewering, was undesirable because
of its apparent high cost and its potential for induced
development;
103
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Exhibit 6-2, p. 2
MILLTOWN COMMUNITY-WIDE CONCEPT DEVELOPMENT
Problem Area
1
2
3
4
5
6
7
8
9
10
Community -Wide Concept
1
E-K
C
C
D
E
H
B-C
E
D
B
2
E-K
B
B
B
B
B
B-C
B-C
B
B
3
K
B
B
B
J
B
F
B-C
B
G
4
A
A
A
A
B
B
F
B
B
A
5
A
A
A
A
A
B
F
B
B
A
6
A
A
A
A
A
A
A
A
A
A
A Convey to treatment outside area
B Convey to common SAS
C Mounds where required
D Water conservation and retrofit alternating SAS
E Waterless toilet; use existing system for graywater
F Connect 4 more houses to existing sewer system and common
septic tank, install common SAS.
G Treat for direct discharge
H No action until failures
J Convey to package plant for land application
K Convey to treatment plant, with disposal by rapid infiltration
104
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Exhibit 6-2, p. 3
SUMMARY OF COSTS FOR EACH CONCEPT
(thousand $)
Capital costs
Federal/ state
grants
Local Capital
costs
Annual O&M
Annual O&M +
Debt Service
Present Value
Ranking
Community -wide Concept
1
$1,468
1,380
88
101
111
3,543
No3
2
4,373
4,111
202
121
151
6,503
Yes
3
4,979
4,681
290
160
194
7,083
Yes
4
6,581
6,186
395
165
211
8,452
Yes
5
7,106
6,680
426
176
226
9,033
Yes
6
9,545
8,972
573
154
323
12,010
No4
94% of construction costs without salvage
2at 6 5/8% for 20 years
2
technologies unacceptable to the public, based on open meetings
4
too expens^ve
105
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uL 6-2, p. 4
CONCEPT #2: ON-SITE AND COMMUNAL SYSTEMS
, (OMMff
Sewer to Treatment
and Land Disposal
Sewer, Common
Disposal Field
j Add Common SAS and f
Mounds
CONCEPT #4: CENTRAL SEWER SERVICE AREA
Sewer, Common
Disposal Field
Treatment Plant
Sewer Service
Area
106
Add Common SAS
and Mounds
-------
tx.lu.b
-------
This step can be complex, as shown in Exhibit 6-2. On the other hand, it may
be relatively simple, almost to the point of being trivial, as shown for Sea-
town in Exhibit 6-3. In either case, these concepts should be presented to the
Board, along with evaluation data including:
• rough system cost estimates, probably from cost curves (total
capital cost, annual O&M, life cycle cost, grant eligibility);
• estimates of the extent to which each concept could serve pro-
jected new development, shaded on a map.
By clearly stating the constraints and resulting limitations in this step, the
engineer helps the community reach a concensus on where to focus future analy-
sis. This concensus is the basic goal of this step in the methodology.
6.3 DEFINING APPROXIMATE BOUNDARIES FOR SEWER SERVICE AREAS
This stage in the analysis may have to be performed twice. Ideally, one would
choose the area to be served by sewers at the same time as one chose the trans-
port technology. However, both steps are complicated, and the analysis quick-
ly becomes unwieldly. In defining sewered area boundaries, therefore, it is
useful to initially work with whatever transport technology appears likely to
be least-cost, and then check the results once technologies are selected in
the next step.
The goal of this step is very simple: to define the extent and maximum flow of
all sewer service areas for each concept, and to determine how much of the com-
munity will continue to use individual on-site systems. To do this analysis,
it is necessary to identify a range of sensible options for the various sewer
service areas, preparing estimates of costs and of impacts on development. Ex-
plicit decisions on time-staging and on excess capacity should, if possible,
be addressed later. However, the projected sewer service areas may include
undeveloped land, and this would raise issues of excess capacity and funding
eligibility.
In some cases, such as Exhibit 6-4 for Hilltown, the number of options may be
quite small. In others, there may be several options open to serve the exist-
ing development, and even more when extensions to undeveloped land are consi-
dered. Some of these options may involve combinations of collection technol-
ogies including conventional gravity, effluent pump or grinder pump pressure,
vacuum, or small diameter gravity sewers. The cost analysis must include
both eligible and ineligible costs with the local cost highlighted.
Two concerns are paramount for determining the extent of sewers: tradeoffs be-
tween centralization and on-site technologies for existing development; and ex-
tension of sewer service areas into undeveloped land.
The major difficulty is determining what level of detail on sizing and cost-
effectiveness is necessary for the task of defining sewer service areas. The
following procedure has been developed for optimizing the size of each sewer
service area.
First, the desired range of sewer service areas for the community should be
mapped on the basis of the concepts developed earlier. Then for EACH SERVICE
108
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Exhibit 6-2
SEATOWN
CONCEPT DEVELOPMENT
Centralized discharge location
for areaa 1, 2, 3, and 4.
CONCEPT DEVELOPMENT FOR SEATOWN
The Seatown analysis is probably typical of the level of effort
required in this step of the community-wide evaluation and was, in
fact, trivial. There was only one feasible discharge point for a
wastewater treatment plant: in the cooling water input channel for
the power plant (another community uses the output channel). Land
application was not feasible, because of wet climate, high ground-
water table and poor soils. Continued use of on-site technologies
was only possible in problem areas 5 and 6, given current problems
in areas 1-4. While surface water discharge options, such -as long
discharge pipes, could have been investigated, it was clear upon
minimal analysis that the channel was the most reasonable surface
discharge point. The major issue was how far to extend sewers, a
question which is a major topic of the next stage of the community-
wide analysis.
Therefore, there is only one concept developed here: discharge of
all collected wastes into the power plant cooling water input chan-
nel after treatment to secondary quality. This concept is shown
on the map.
109
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Exhibit 6-4
r
j
HILLTOWN
Preferred Alternatives for
J Individual Problem Areas
CHOOSING SEWER SERVICE AREAS FOR HILLTOWN
The map shows the preferred alternatives for the individual
problem areas in Hilltown, with the major developed areas (#s 1, 4,
and 5) served by collection and secondary treatment. The two
smaller central districts (areas 2 & 3) would be served by indivi-
dual on-site systems with management. The concepts developed in
the first stage of the analysis included:
o separate sewer systems for areas 1 and areas 4 & 5, with
on-site management in areas 2 and 3;
o sewering of all areas, with a single plant.
The use of an on-site district for all problem areas was rejected
because it would not solve existing problems: many of the systems
could not be brought up to standard with management and rehabilita-
tion. Such a district would, however, be better than nothing, so it
was recommended as a short-term option.
In the western area, three levels of sewer service were considered
in the first stage: local subsurface disposal, centralized land ap-
110
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Exhibit 6-4, p.2
plication in the area, and transport outside the area. The first
was rejected because of land acquisition problems, since there are
few areas in Hilltown with acceptable slopes, and those are prime
development sites (or already developed). Centralized land appli-
cation was possible, but suitable sites were unavailable; building
a treatment plant as a precursor to land application was evaluated,
but would have been much more expensive than transport to the east-
ern areas.
Therefore, the only available concept was centralized service, ser-
ving both the eastern and western areas of the community. The exist-
ing treatment plant and disposal areas would be expanded to treat
the wastewater from both areas. The remaining questions were rela-
ted to the actual extent of service at the edges, and in problem
areas 2 and 3.
Given that an interceptor from area 1 to the treatment plant would
have to pass through areas 2 and 3, marginal analysis showed it
cheaper to connect these areas than to perform frequent rehabilita-
tion of failing on-site systems.
Marginal analysis could also have been used at the edges of the pro-
posed sewer systems, but this was dispensed with by using a rule of
thumb: since the problem in the area was soils of low permeability,
it was assumed a density of one house per two acres was acceptable,
and that on-site disposal could be performed for these low-density
lots at less cost than sewering. This assumption will be checked
in the detailed design studies for Step II of the grants process
and is only a simplification for planning. The result is that
areas developed at higher densities were provided sewer service,
with on-site management for the low density sites.
Thus, the problem area alternatives were quickly reduced to one sys-
tem concept, where technologies could be compared: general collec-
tion and transport to an expanded treatment plant with land applica-
tion at the current site.
TIT
-------
AREA the engineer should:
• order the options from smallest to largest extent of service;
• estimate the population served in each service option, based on the
future community growth (work with the local officials).
• take the smallest option and - using the most promising collection and
treatment technologies - estimate collection and treatment costs for
the design population;
• do the same for the next smallest option. Then compare the follow-
ing costs:
a. cost per household served, for the larger service area
b. cost per household served for the same area, but with only
a portion sewered. This will be a weighted average of
the per household costs for households served in the
smaller sewer service area and the per household costs for
conventional on-site systems for the remaining household.
• if the cost per household for the larger option for that service area
is lower than the cost per household of the smaller sewered option
(plus necessary on-site systems), proceed to the next larger option
and repeat the, comparison; if the cost is higher, stop and select the
least cost option.
By the marginal analysis approach, it should be possible to select the best
size for each service area, though this may not be best when all service areas
are considered together. Exhibit 6-5 provides an example of this marginal
analysis approach for a hypothetical service area.
Once the best sizes have been selected for each service area, the engineer
should work with local officials to allocate the projected growth over the
next 20 years among the sewer service areas and the areas served with individual
systems (see Exhibit 6-6). Total costs and local shares should then be compared
among community-wide systems, using the service area boundaries developed.
The result will be an estimate, for a given sewer technology, of how far sewer
service should be extended for each service area, and this is the desired out-
put for this stage of the process.
6.4 TECHNOLOGY SELECTION
By this point, the sewer service areas, if any, and the possible points of
wastewater disposal have been defined. Thus, this step is directed at defining
the technologies to be used for each subsystem of wastewater transportation,
treatment, and disposal, either on-site or centralized, as well as preparing
detailed cost estimates.
The collection systems must be laid out for the areas served, and elevations
identified to determine pumping requirements. Alternative collection techno-
logies must be considered in this cost analysis where applicable, though con-
sistency across areas is useful. This is the focus on the Hilltown example,
112
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Exhibit 6-5
D + m = Units in extended
service area
• = Units in
service area
a a
a a
m m m
Disposal Area
AN EXAMPLE OF MARGINAL ANALYSIS OF SEWER SERVICE AREAS
Consider the extended and basic sewer service areas show in the map.
In the extended,90 households are served by collection and centralized
disposal. In the basic, only 60 households are served by the same tech-
nology 3 reduced somewhat in size, the other SO are distributed around
the community in areas where conventional on-site systems are acceptable,
The cost per household for the extended system was estimated at $3800.
Because of economies of scale3 the unit cost for the basic system was
$4700. However, the costs per household of conventional on-site in
acceptable areas was only $1500.
To compare the costs of serving all 90 households under the two systems,
it is useful to look at either total costs or a weighted average:
Service Area
Basic
Extended
Technology
Sewered
On-site
Mix
Sewered
Units Served
~60
30
90
90
Unit Cost
$4,700
1,500
3,633
3,800
Cost
$282, 000
45, 000
327,000
342,000
While the difference is not large, the cost of the smaller sewer system
including the cost of on-site systems for residences not connected is less
than the cost of the extended sewer system. In addition, limits on grant
eligibility for capacity to serve new growth may increase the local share
for a system serving the larger service area, accentuating the difference.
1X3
-------
Exhibit 8-6
GROWTH ALLOCATION IN SEATOWN
The basic concept for Seatown involved providing sewer service to
problem areas 1-4, while leaving problem areas 5 and 6 served by
on-site management, and zoned for relatively large lots. The table
shows how future growth was allocated to the individual problem
areas to meet the project population for the year 2000. Here,
much of the development goes to the coastal areas at high densities,
made possible by provision of sewer service; most of the remaining
development is placed in problem area 6, where the soils are rela-
tively good, and where there is good transportation to other parts
of the region.
The engineer can develop a tentative allocation such as this, but
it is important to have such allocations approved by the Board.
Decisions on the allocation of future growth are likely to be
politically important, but are also necessary for the sizing of
wastewater collection and transport networks.
SEATOWN GROWTH ALLOCATION
Problem Area
1*
2*
3*
4*
5
6
Track II
Total
Population
in 1976
465
2218
162
241
0
297
213
3596
New Growth
288
2382
309
418
185
595
187
4404
Population
in 2000
753
4600
471
659
185
932
400
8000
*Sewered
114
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shown in Exhibit 6-7. At the same time, options for wastewater, sludge, and
septage treatment must be evaluated and estimates made of unit costs, which should
be more detailed and site specific than the generic ones of the earlier stages.
To do both of these analyses, it is first necessary to estimate the required
capacity for each collection and treatment system, using the anticipated devel-
opment patterns from the previous stage.
For the comparison of technologies, the engineer should usually assume that time-
staging is irrelevant, and work with the design population. In other words, assume
that the optimal mix of technologies to serve the full community at the end of
the planning period will also be the best choice now. Time-staging to reduce
current costs will be considered later, in the final stage of the evaluation
(Secton 6.5), since it should not affect the choice of systems—only the deci-
sion of what to build now.
The evaluation criteria include:
• cost, both total and local share (including public and private);
• local environmental impacts of the facilities;
• ease of operation and maintenance (which includes use of similar
technologies wherever possible);
• public acceptance;
• performance (and risk).
Since the systems are well-defined at this point, the cost analysis can follow
the EPA Cost-Effectiveness Analysis Guidelines (except for time-staging and
other cost reduction measures). Complete costs should be estimated, grant-
eligibility should follow the Guidelines, planning horizons and salvage values
should be chosen as applicable for the technologies. All costs should be in-
cluded, whether public or private, (including, for example, house connections).
In other words, the evaluation should follow Step 1 requirements.
It may be necessary to repeat some of the earlier analyses at this point.
For example, extremely high land costs for disposal within a problem
area could imply that it should be served by an outside facility rather
than a series of communal drain fields. Similarly, analysis of pressure
sewer collection might also show benefits from expanding the sewer service area,
which was defined based on the costs of gravity systems. Or, public comment
might lead to changes in the handling of future growth. However, these itera-
tions should be limited in scope, so that the goals of this stage can be
achieved.
Some of the analyses in this step can be piecemeal. For example, it is possible
to take a given wasteload and set of disposal requirements and estimate the
costs of a number of different treatment options; the same is true for collect-
ion technology. The only interaction arises when the collection systems being
compared handle different types of wastes (e.g. conventional gravity sewers carry-
ing raw sewage compared to small diameter sewers carrying septic tank effluent).
115
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Exhibit 6-7, p.l
TECHNOLOGY SELECTION IN HILLTOWN
Three technologies were considered for wastewater transport for
Hilltown, under the assumption that the existing treatment plant
and disposal system would be expanded to serve the additional
loads:
o conventional gravity sewers;
o low pressure sewers with grinder pumps;
o vacuum collection systems.
For all options3 septage disposal was assumed to be effected at
the expanded treatment plant. STEP pressure sewers, with lower
maintenance costs than grinder pumps, were eliminated by the
engineer because of the expected high costs for replacement of
existing septic tanks.
The first table presents the present worth for the capital costs,
and also for operations and maintenance, based on Federal grants
of 75% for the conventional gravity sewers and 85% for the pres-
sure and vacuum sewers and the treatment plant, plus state grants
of half of the remaining grant eligible amounts in each case.
The lives for all sewers are assumed to be 50 years, with salvage
values computed after 20, and costs for replacement of short-
lived items such as grinder pumps are included in the annual O&M.
The table shows the total present worth for the system and the
present worth of the local share, as well as the local costs per
household per year (all in constant dollars).
Note that all costs include the house connections ("service lat-
erals") and that all systems have the same number of households
served. All systems also transport all wastes from the house-
holds. Thus, while the cost analysis does not include costs in
the unsewered areas, the costs are consistent across all options.
On the basis of this analysis of technologies, vacuum sewers
were selected as the recommended option from this stage of the
evaluation. They were also believed in this case to lead to less
construction impact than conventional sewers, and to have similar
maintenance requirements to the grinder-pump pressure sewer option.
The potential costs for serving new growth were analyzed for the
three systems by looked at the incremental costs of new services,
as shown in the second table.
116
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Exhibit 6-7, p. 2
HILLTOWN COST SUMMARY
CONVENTIONAL
GRAVITY
Transport System
PRESSURE VACUUM
Total Present Worth
Grant Eligible Amount
Conventional Grant at 75%
Alternative Grant at 85%
State Grant
Present Worth to District**
Present Worth Per Residence
Average Monthly Charge Per
Residence
$11,102,284
8,678,200*
5,554,720
1,092,454
1,015,513
3,449,497
2,029
15.'97
$8,523,577 $7,926,520
6,283,381 5,829,520
5,340,874
471,253
2,711,450
1,595
12.56
4,955,092
437,214
2,544,214
1,497
11. 78
*1,285,240 at 85% (sewage treatment plant and a few grinder pumps
in outlying areas); $7,392,960 at 75% (gravity sewers).
**Total present worth minus State and Federal grants.
Gravity
Pressure
Vacuum
Incremental Costs for New
Households (Present Worth)
Construction O&M Total
$ 66,236 $10,000 $77,036
$206,985 $69,733 $276,718
$ 84,815 $69,733 $154,548
Total Local Present Worth:
Existing and New Users
$3, 526, 5Z3
$2,988,168
$2, 6983 762
Here, it was assumed that the new development would fill in un-
developed lots, near the wastewater transport network. The new
construction costs for gravity sewers would be for service
laterals, while the pressure system would require 200 new grinder
pumps, with associated O&M. For the vacuum system, no new central
vacuum stations would be required, though valves would be necessary
at the households. It was assumed that short-lived equipment would
require maintenance, and that pumping costs would increase because of
the increased flows.
Thus, the incremental costs to serve new development were lowest
for the gravity sewer system, and highest for the pressure sewer
system. Since it was assumed that the new development would not be
grant eligible, these costs are added directly to the local share.
However, they do not shift the relative rankings of the three systems,
so the vacuum system was selected.
117
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One important criteria is that the systems be both operable and maintainable;
another is that they be likely to work. At the very least, these criteria im-
ply that the various systems in the community be compatible: that, as much as
possible, similar technologies are used throughout. While the Exhibit 6-4 for
Hilltown showed three types of collection technologies as optimal for three
types of areas, Exhibit 6-7 selects a single technology to be added to the ex-
isting system.
Innovative technologies involve more risk than conventional or alternative
technologies, and this would, in the abstract, be a drawback. However, the
Federal government has decided to absorb some of that risk, in an attempt to
develop and demonstrate these innovations. The big risks for the community
come not when the proposed system is innovative, but when the choice is a
conventional system which should work in theory, but is poorly designed or
badly operated. Thus, ease of operation and maintenance is desirable for any
treatment or transport system.
The compatability of the technologies is also a factor in sludge management.
In most small communities, septage disposal will be a consideration, unless all
areas are served with sewers carrying unprocessed wastewater. On the other
hand, ST3P sewers might be desirable if only a small part of the community is
served, because septage collection and treatment would be required for the in-
dividual systems. This septage collection system could easily be extended to
the sewer service area as well. If the plan calls for septage to be landspread,
jand a compatible sludge from wastewater treatment can be generated, the same
systems for stabilization and disposal could be used.
Environmental considerations apply in this stage as well. In the choice of
technologies, issues such as construction impacts are likely to be extremely
important. In addition, localized impacts such as odors and esthetics may be
the deciding points between various treatment and residuals disposal options.
Public participation in this step will allow the engineer to assess how im-
portant these impacts are in the particular situation, along with providing
more information about the ability of the community to operate and maintain
the suggested systems. While several concepts may still be under considera-
tion, it is necessary that the technologies fit the needs of the com-
munity. Public participation is one of the best ways to evaluate
these community needs.
The result of this stage of the analysis will be a set of well-defined systems
with identified service areas and technologies, which could serve the
population at the end of the 20-year planning horizon.
6.5 MANAGEMENT, COST ALLOCATION, AND DETAILED EVALUATION
The final stage in the analysis bf community-wide systems, and in the pre-
paration of the Step 1 plan, is to take the systems defined by the earlier
stages and perform a detailed cost-effectivenesss and environmental evaluation
on them, repeating earlier steps if improvements can be made.
Where the installation of a sewer system has been deemed necessary, it has
been general practice to consider in the cost-effective analysis only the
costs related to providing the sewer services. However, there are usually
118
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many existing units outside of the service area which will continue to rely on
on-site systems. In order to make a fair comparison between various community-
wide options it is important that the costs of maintaining and ultimately re-
placing these systems must be considered. Even if the responsibility for in-
dividually-owned systems remains exclusively with the owner, capital costs for
individual systems installed by developers should be estimated. It is particu-
larly important that provisions be made to insure the long term operation of
these outlying privately-owned systems in order to avoid the public costs as-
sociated with connecting such units to a collection system in the future.
The Cost-Effectiveness Analysis Guidelines* require that options be analyzed
for their full costs, which is interpreted here as the full costs of
wastewater service for the complete community, including maintenance of
existing and future on-site systems. It requires consideration of time-
staging of construction, which is straightforward given the following:
o the initial population
o estimates of scale economies, and
o the desired system structure at the end of the planning period.
Therefore, all the necessary information for the cost-effectiveness analysis
is available from the earlier stages of the process.
The same is true for the analysis of direct and indirect environmental impacts:
for each concept, all sites have been located, and technologies have been
chosen for them. Locations of projected new development have been defined for
each option, and excess capacity for growth can be estimated from the sizes
of the various transport and treatment facilities. Therefore, it is possible
to map where extra development is feasible under each option, and present these
results. Exhibit 6-8 provides an analysis of growth issues for Seatown. An
excess capacity map can be used along with methods for estimating municipal
service costs (school, police, etc.) to evaluate the local costs of growth
above or below the design level.
The institutional aspects, however, remain to be defined. One institutional
issue is cost allocation. In presenting the results, it is useful to present
costs for an average resident in the community, but it is even more useful
to present the actual expected costs to each class of residents. In this stage,
therefore, alternative cost sharing arrangements should be defined, and esti-
mates made of how the system costs will be allocated to those provided with
different types of service. In other words, the operations and maintenance
arrangements and financing methods must be selected, with alternatives pre-
sented to the community. In many cases, this is fairly easy: the wastewater
district should own and manage any centralized facilities, so the major
questions arise with respect to on-site and communal systems. These can be
privately owned and managed under a permit system, privately owned and pub-
licly managed, or publicly owned and managed. In the first case, the resident
must comply with regulations, but pays all costs for maintenance, pumping, and
—where necessary—rehabilitation. In the second option, the resident pays
user charges to the local district, which performs the necessary maintenance,
though this probably does not cover rehabilitation. In the final option, the
*Appendix A of 40CFR35.
119
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Exhibit 6-8
PLAN
Fully
grant-eligible
system
Increased inter-
ceptor and pump
capacity
Addition of inter-
ceptors for the
Central areas
MAXIMUM SYSTEM
CAPACITY (Persons)
coastal
8,520
12,000
12,000
central total
1,412 9,932
1,412 12,412
6,000 18,000
CAPITAL
local
0.36
1.16
2.66
COSTS (Million $)
federal
2.04
2.04
2.04
total
2.40
3.20
4.70
POTENTIAL FOR GROWTH IN SEATOWN
After the initial negotiation with the grant officials, it was agreed
that the grant-eligible design population for Seatown would be 8,000.
However, the community was still interested in considering the provis-
ion of service to accomodate a population of up to 18,000 by the year
2000. The Board asked the engineer to analyze the local cost of pro-
viding the additional capacity.
The engineer first analyzed systems designed to meet the needs of the
grant-eligible population based on the allocation of expected growth
described in Exhibit 6-6. The recommended plan called for conventional
gravity sewers and secondary treatment for the Coastal problem areas,
with continued use of septic tanks with alternating SAS (either individ-
ual or cluster) in the Central problem areas.
In the Coastal areas, the actual capacity of the proposed sewer system
was somewhat greater than the design population because of hydraulic
design constraints. With relatively minor changes in interceptor
sizes and pumping station capacity the overall capacity of the sewer
system could be increased at a low marginal cost (although the local
share of capital costs triples).
The engineer also evaluated providing additional excess capacity at
the treatment facility at this time as opposed to staging it to meet
future needs, and looked at the cost of providing interceptors for
the central areas as an inducement to growth.
While it was not cost-effective to provide the excess plant capacity
at this time, the three options for the transport system were presented
to the community, and are shown in the above table.
120
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public body provides wastewater service for all households and collects user
charges to pay for the service. All construction., operation, and maintenance
tasks are performed by the public agency, or firms under contract to it.
However, these are just the basic classes of arrangements, and the details are
extremely important. These details need to be evaluated for the particular
case by the engineer, and presented to the community. Costs for the various
options may be affected slightly by the organizational arrangement, and the
distribution of costs depends greatly on the financing methods chosen. For
example, in the above list, on-site system failure can be the responsibility of
either the resident or the community; similarly, the costs of larger facilities
can be paid by the people using those particular facilities, or by the community
as a whole since all receive service of equal quality.
Exhibit 6-9 presents the distribution of costs under various institutional ar-
rangements for Hilltown, using the vaccum sewer option. Besides the cost al-
location, there are a number of other institutional considerations which must
enter in this step. The primary one is that every necessary component of system
design, installation and operation must be provided by some part of the insti-
tutional structure. Exhibit 4-11 showed the necessary management functions,
and was suggested for us as a checklist to analyze the powers and responsibili-
ties of the various existing institutions. It is repeated here as Exhibit 6-10
since the engineer must ensure that each of these management functions is the
responsibility of some institution, though this may require establishing some
new institutional arrangements.
Institutional issues such as these need to be decided here, since this is the
final evaluation step. At this point, technical options have been analyzed for
each problem area, and used to identify system concepts. Those concepts have
been developed into complete wastewater management options by first analyzing
disposal sites and overall characteristics of the concepts, then choosing a
reasonable range of sewer service areas, selecting technologies for collection,
treatment and disposal, and finally evaluating the cost-effectiveness,
environmental impacts, and institutional arrangements for these full systems.
All that is left is for the community, through the wastewater agency and the
public meeting, to select the best available system and submit the Step 1 plan.
6.6 FINAL RECOMMENDATIONS
It is assumed here that the engineer is familiar with the requirements for a
Step 1 plan, which vary somewhat from state to state. The previous section
followed the methodology to the point of preparing detailed cost and environ-
mental impact assessments of the best alternative systems for the community, and
developing recommended institutional structures. At this point, it is time for
the engineer to present these data to the Board for selection of the recommended
plan, and to present the recommended plan and alternatives to the community at
the public hearing. Given an effective public participation program throughout
the planning process, though, this should be relatively straightforward.
The Step 1 plan, with its associated environmental assessment, must be signed
by the Board, since the Board was designated by the community as the responsible
121
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Exhibit 6-9
DISTRIBUTION OF COSTS IN HILLTOWN
There are innumerable ways to charge for wastewater service. In
a system suoh as Hilltown, involving an existing sewer system, a
proposed system, and some households served by neither, the
question of how the charges should be allocated is complex.
The total bill is about $270,000 annually; there are several
options for dividing these costs among the residents in the com-
munity. One of the simplest is just to have a service district
which provides all households with wastewater service, incurs
all costs, and divides them equally: this would amount to an
assessment of about $8. 74 per month to all households.
If the district served only the sewered areas, the assessment
for those served would be $9.42/month, and the average cost for
those with individual systems would be about $6.20 per month.
On the other hand, the range of costs for individual systems would
be large, because of variations in pumping frequency and need
for replacement. In any year some would pay nothing, others up
to several thousand dollars.
A community-wide management district could even out these payments
by dividing the costs for the few replacements each year among
all users. With public ownership, the household would pay a fixed
charge of $6.20 per month for a permit, annual inspection, pumping
when necessary^, and any rehabilitation or reconstruction which
would be required.
In the sewered areas, the local capital costs could be paid in
several ways, but the most common are
o complete averaging among the users;
o costs allocated by water flow metering, and
o frontage and connection fees.
In the first and second all costs are divided among all users,
leading to the average assessment of $9.42/month. In the latter,
households in the new service area pay for the feet of sewer line
frontage they have, plus the full costs of their house connection
line, plus a user fee (an average of about $10.43/month). Households
122
-------
Exhibit 6-9, p.2
in the old service area pay any remaining debt service and interest,
plus about $4.25/month in user fees.
Putting all these costs together for this option leads to the following:
o New Sewer Service Area: average costs of service of
$10.43/monthj paid through, user charges or through a
combination of frontage, connection, and user charges;
o Old Sewer Service Area: user charges of $4.25/month;
o Individual On-Site Systems: an average of $6.20/month for
permitting operation, maintenance, and replacement distributed
very unevenly across the systems.
Because high private costs for rehabilitation will lead to
problems in replacing failing on-site systems, and because the
community wishes to promote sewer connection in the areas
where on-site systems are currently affecting water quality,
it is recommended that the community implement options which
equalize the costs across systems served in similar ways.
There are three recommended options:
#1: Charge each type of user a class rate:
o $6.20/month for individual on-site systems,
including permits, inspections, maintenance,
rehabilitation, and district management costs;
o §4.25/month for households served by the
existing sewer system;
o $10.43/month for households served by the
new sewer system and added plant capacity.
#2: Treat all s&wer system users equally:
o $6.20/month for individual on-site systems;
o $9.42/month for sewered households.
#3: Treat all users equally:
o $8.74/month for all households, with the
district taking responsibility for all costs
except those caused by customer negligence.
123
-------
Exh-ib-it 6-10
ON-SITE MANAGEMENT FUNCTIONAL RESPONSIBILITIES CHECKLIST
(A completed form is shown as an example)
3
i
5
a,
INSTALIATION
OPKKATION
MAINTENANCE
MONITORING
ALTERATION 1
FINANCING
Design Standards
Design Engineer Licensing
Site Feasibility Analysis
Plan Review
As-built Plan
Coordination with other
local boards
Installer Registration
Performance Bond
Excavation Inspection
Leaching Field— ?ill
Inspection
Leaching Field-- Srade
Inspection
Backfilling Inspection
Occupancy permit
Public Education
Pumping
Pumper Registration
Recordkeeping
Surface Water Quality
Groundwater Quality Testing
Water Quality Monitoring
Repairs
Dwelling Unit Conversions/
Enlargements
Installation Fee
User Charge
Annual Appropriations
HE.
Public
^
iS
r
r
^
^
^
f
^
r
r
f
r
SONSIB^LITX
Private
r
r
r
t/
r
^
f^
Not Don*
r
//
^
r
f
>/
REQUIREMENTS/COMMENTS
State Sanitation Code requirements incorporated into County
Health Code; County has added requirements for alternating
fields
State requires that system designer be a licensed sanitary
engineer or oass state certification test
County requires deep pit observation holes in addition to
state mandated perc. test; also requires soils analysis for
certain sites; site analysis witnessed by county sanitarian
County sanitarian reviews final plans within 45 days as per
state sanitation code; systems >15,000 gpd in size
forwarded to District Environmental Health Office for review;
detailed plan requirements— copy enclosed
County requires as-built plan be filed with County Health
Deoartment prior to occupancy oernut issuance
Building inspector occupancy permit contingent upon County
Health Department ok; the building inspector also screens
dwelling unit changes for additional on-site system requirements
County requires installer to file a $2,000 performance bond
with County; refunded after satisfactory system operation for
365 days
County sanitarion inspects backfilling operation; 48 hour
notice required.
County Health Department must approve Building Inspector
occupancy permit at each change of ownership in a dwelling
unit.
Brochure on appropriate user habits for on-site systems
distributed at issuance of occupancy permit; also published
semi-ar.nualiy in local newspaper
Occupany permit tied to a mandatory pumping of septic tank
once every three years; notice mailed to occupant at appro-
priate time; pumpout receipt required to be mailed back
within 60 days after pumping.
Private pumpers who serve homeowners are regulated oy an
annual registration form; required to return a copy of eacn
form to county uoon appropriate septage disposal
Through the occupancy permit renewal process and septage pump-
out receipts. County is tracking performance of all systems;
failures being correlated with user habits (through special
survevl as-built plans and soils
County Sanitarian monitors nitrate levels for public wells
that are in densely developed areas; water department conducts
water quality analvsis as per state requirements
County regulates all repairs as if they were new installations;
same regulatory process must be adhered to
County Buildir.g inspector notifies County Sanitarian of
dwelling unit changes for possible additional on-site
disposal requirements
County requires a $75 fee for reviewing design plans,
witnessing site feasibility analysis, and witnessing
installation
County levies a. S25 user charge for the renewal of all
occupancy permits to cover administrative expenses
Health Department receives an annual appropriation from
the County general fund for department budget
124
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local body. In addition, the Step II application should be prepared at this
time, though EPA must make a determination of whether an Environmental Impact
Statement is required before the Step II grant application can be processed.
Existing EPA guidance, and information provided by the State, should provide
all the necessary instructions for these documents, which can be prepared
based on the analysis employing the methodology described here.
125
-------
APPENDIX A
UNIT PROCESSES AND TECHNOLOGY OPTIONS
TABLE NUMBER TITLE
A-l HOUSEHOLD WASTEWATER GENERATION, 127
A-2 ON-SITE TREATMENT ALTERNATIVES, 128
A-3 ON-SITE EFFLUENT TREATMENT/DISPOSAL OPTIONS, 129
A-4 TRANSPORT ALTERNATIVES, 130
A-5 CENTRALIZED TREATMENT OPTIONS, 132
A-6 CENTRALIZED EFFLUENT DISPOSAL, 135
A-7 SOLIDS STREAM TREATMENT OPTIONS, 136
A-8 DISPOSAL OF SOLIDS, 137
126
-------
TABLE A-l
HOUSEHOLD WASTEWATER GENERATION
FIXTURE
OPTION
EFFECT
COMMENTS
Toilet
Others
Conventional water closet
Low flush (2-3 gal/flush)
Very low flush (<1 gal/flush)
Waterless toilets:
composting
incinerating
Recycle toilets
Pressure reducing valve
Low-flow shower heads and
flow restrictors
Faucet controls
Water conserving appliances
Hot water pipe insulation
Moderate flow reduction; increased
pollutant concentrations
Significant flow reduction; increased
pollutant concentrations
Renewal and treatment of toilet waste;
significant flow reduction
Total combustion of toilet waste;
significant flow reduction
Removal and treatment and/or storage of
toilet wastes—significant flow
reduction
Moderate flow reduction; increased
pollutant concentrations
Low to moderate flow reduction
Low overall flow reduction
Moderate to significant flow reduction
Maintains water temp, in pipe; moderate
water savings
Effective; requires 4-5 gal. water per flush
Retrofit effective; well demonstrated
Some units require small air compressor;
retrofit effective; well demonstrated
Small units use heating element; retrofit with large
unit may be difficult; residuals removal required
periodically
High energy requirement; ash removed periodically
May use oil or water—base flushing fluid; generally
too expensive for individual homes; residuals
removal required
Retrofit effective; well demonstrated
Simple low-cost retrofit; can be effective depending
on user habits
Retrofit effective
Retrofit effective; cost equivalent to conventional
appliances
Retrofit may be difficult
-------
TABLE A-2
ON-SITE TREATMENT ALTERNATIVES
OPTION
to
CO
Septic Tank
Aerobic Sysltem
COMMENTS
Well-demonstrated, low-cost; requires
removal of septage every 3-5 years,-
effluent does not tr.eet secondary standards
Most systems well demonstrated; high O&M
requirements; process control required;
potential to produce secondary effluent;
periodic sludge removal required.
-------
TABLE A-3
ON-SITE EFFLUENT TREATMENT/DISPOSAL OPTIONS
OPTICS
USE
COMMENTS
to
P
Filtration
Disinfection
Halogens
Ultraviolet
Ozone
Surface discharge-
Evapotranspiration
Soil absorption systems
Conventional (leaching
fieIds, trenches,
chanters, pits)
Modified dosing tanks,
pressure distribution
Alternate fields
Mounds
Treatment/Reuse
Auxiliary treatment before surface
discharge
Before surface discharge
Transport of effluents to the air
by evaporation and transpiration
Transport of effluent to groundwater
by means of sub-surface application
Gravity distribution
Provides for resting of soils and better
effluent distribution
Provides annual resting of soils
Allows subsurface disposal in areas
with high groundwater
Toilet flushing, lawn watering, etc.
Demonstrated; requires moderate operation and maintenance,
pumping usually required
Not widely demonstrated; chemicals required
In development; high OfiM costs
In development; high OEM costs
Demonstrated; relatively simple discharge outlets required;
regulatory problems likely
Demonstrated; very climate sensitive; high land requirements
in most installations; high construction costs
Demonstrated effective in good soils; generally low cost
compared to other on-site alternatives
Useful in marginal solids to retard clogging; most significant
in large systems (see 2.5); moderate OSM
High construction costs; demonstrated and effective
High construction costs; demonstrated and effective
May be applied to segregated waste streams (e.g. greyweter) ;
many variations possible; may have hiqh capital and OSM
costs
-------
TABLE A-4
TRANSPORT ALTERNATIVES
Conventional Gravity Sewers
Grinder Pump Pressure
Sewer s
Vacuum Sewers
Hauling (holding tank
and truck)
PHYSICAL CONSTRAINTS
CONSTRUCTION
A. Flat or changing topo and
basement drains may require
Deep Cuts
B. Bed rock
C. Groundwater
A. Few restrictions on topo,
bedrock , groundwater
B. Requires grinder pump and
holding tank for each
connection to main
A. Less constraints than
conventional but greater
than pressure
A. Requires holding tank at
each connection to main
OPERATION
A. Place below frost line;
lift stations may be re-
quired
B. Deep Cuts, lift stations
increase costs substantially
C. Infiltration
A. Place below frost line
B. Power source required at
each connection to main
C, Pump maintenance
A. Place below frost line
B. Vacuum valve at each
connection to main
C. Central vacuum pump
A. Regular pumping of holding
tanks
B. Requires availability of
treatment plant or land
application site (winter
storage)
COWtENTS
Well demonstrated
Advantages : No pretreatment required
No on-site equipment required
Public acceptance
Concept and design well demonstrated. Additiona.
needs in hardware and maintenance.
Advantages: Uses small diameter plastic pipe
installed near grade
Cost is less dependent on site
constraints
No infiltration/inflow
Needs demonstration : hardware , maintenance
Advantages: Cost is less dependent on site
constraints; reduces water use
No I/I
Well demonstrated, but costly
Advantages : Best suited fcr isolated residences
without on-site disposal alterna-
tives or interim handling
H
U)
-------
TABLE A-4
TRANSPORT ALTERNATIVES
ALTERNATIVES
PHYSICAL CONSTRAINTS
CONSTRUCTION
OPERATION
Septic Tank Effluent Pump
(STEP) Pressure Sewers
J-1
CO
Few restrictions on topo,
bed rock, groundwater
Requires septic tank, holding
tank and effluent pump at
each connection to main
A. Place below frost line
B. Power source required at
each connection to main
C. Pump and septic tank
maintenance
D. Odor control (?)
E. Effluent treatment
Concept and Design well denonstrated:
Additional needs in hardware, maintenance,
effluent treatment and odor control.
Advantages: Same as grinder pressure sewers
plus pumps are less costly and
somewhat easier to maintain.
Partially treated effluent.
No I/I
Small Diameter Gravity
Sewers (Effluent)
A. Flat or changing topo and
basement drains require
Deep Cuts
B. Bed rock
C. Groundwater
D. Septic tank required at each
connection to main
A. Place below frost line; lift
stations may be required
B. Deep Cuts, lift stations
increase costs
C. Infiltration
D. Septic tank maintenance
E. Odor control (?)
F. Effluent treatment (?)
Needs demonstration; scouring velocities/pipe
slope maintenance, man holes/cleanouts, odors
Advantages: Small diameter pipe, lower
scouring velocities, potentially
less stringent requirement for
manholes
-------
TABLE A-5
CENTRALIZED TREATMENT OPTIONS
Process
Preliminary
Grit Chamber
Bar Screen
Preaeration
Prechlorination
Comminution
Primary
Primary Clari-
fication
Fine Screening
Secondary
Anaerobic
Septic/Imhoff
Tanks
Suspended Bio-
mass (Biolytic
Tank)
Fixed Biomass
(Submerged
Filters and
Discs)
Aerobic Treatment
Intermittent
Sand Filters
Fixed Biomass
Trickling Filters
Level of
Process
Control
Objectives Required
Removal of grit, Low
dirt
Removal of large Low
solids
Odor con tr o 1 and Low
grease removal
Odor control and Low
grease removal
Grinding of Low
solids
Removal of inert* Low
organic solids
Removal of inert* Low
organic solids
Sedimentation/ Low
flotation sludge
reduction
Sedimentation/ Moderate
flotation High
secondary
Secondary and Moderate
nitrogen
removals
Secondary or Low
auxiliary
Roughing and Moderate
secondary
C O N S T R
Land Climate
Low None
Low None
Low None
Low None
Low None
High None
Low None
Low, unit is None
subsurface
to Low None
Low None
High Requires
cover or
special op-
eration in
winter
Moderate Requires
cover in
winter
A I N T S
Operation
May be maintenance
problem due to abrasion
Same as above
Requires Q&M of
aeration equipment
Handling of chlorine
Equipment durability;
Stand-by unit required
Solids must be removed
Solids must be removed;
Equipment durability
Periodic maintenance
Same as above
Requires pre-settled
waste)
Requires auxiliary
treatment;
Requires pre-settled
wastes. Alternate units
may require power
Pre-settled waste;
May require power
Waste Stream Generated
Grit and dirt
Screenings
Scum
Scum
None
Primary sludge
Screenings
Septage
Sludge
Sludge
Periodic sand and
solids removal
Moderate biological
sludge production
Comments
Relatively simple process
Relatively simple process
Relatively simple process
Relatively simple process
Well demonstrated
Very well demonstrated
Well demonstrated
Well demonstrated
Experimental, may be well
suited to wastes with high
BOD
Experimental
Well demonstrated
Simple, low cost
Well demonstrated;
Simple, less susceptible
to upset than suspended
biomass;
May be built above ground
-------
TABLE A-5
CENTRALIZED TREATMENT OPTIONS
Process
Bio Discs
Emergent
Vegetation
Suspended Biomass
Activated sludge
(conventional
and contact
stabilization)
Extended Aera-
tion
Oxidation Ditch
Stabilization
Ponds
Auxiliary
Polishing Ponds
Filtration
Low rate or in-
termi t ten t sand
Mechanically
cleaned high
rate, pressure,
and upflow
filters
Recirculating
sand filters
Expanded Bed
Biological
Filters
Ob3ectives
Roughing and
secondary
Secondary or
auxiliary
Secondary
Secondary
Secondary
Secondary
Solids and
organics removal
removal
Solids and
organ ics remova 1
Solids removal
Solids and
organics removal
Auxiliary
treatment
Level of
Process
Control
Required.
Moderate
Low to
Moderate
High
Moderate
to High
Moderate
Low
Low
Low
Moderate
to high
Low
Moderate
CONSTRAINTS
Land Climate
Moderate Requires
to low cover in
winter
Very high Seasonal
operation
only
Low Treatment
reduced in
cold weather
Moderate Treatment
reduced in
cold weather
Moderate Treatment
to High reduced in
cold weather
reduced in
cold weather
High Treatment
reduced in
cold weather
High to Requires
Moderate cover or
special op-
eration in
winter
Low None
High Special non-
recycling
operation in
winter
Low ?
Operation
Pre-settled waste;
Required power
Pretreated
Pre-settled waste best;
Substantial power
requirements
Less pretreatment re-
quired than convention-
al A.S.; substantial
power requirements
Odor control; Optional
algae control for
nutrient removal
Odor control
Alternate units;
May require power
Alternate units;
Substantial power
requirements
Periodic maintenance;
Requires a pump
Requires pretreatment of
wastes;
Requires power
Waste Stream Generated Comments
Moderate biological sludge Well demonstrated for large
production flows
Crops Demonstrated, needs more info
on cold weather operation
High biological sludge Well demonstrated
production Susceptible to upset from
influent flow or quality
variations
Moderate to low biological Well demonstrated; simple;
sludge production Can accept raw waste; Less
susceptible to upset
Optional Well demonstrated; simple;
low cost
None Well demonstrated; simple;
low cost,- effluent suspended
solids may be relatively higl>
preaeration of septic efflu-
ents may be required
None Same as above
Periodic sand and solids Well demonstrated; simple;
removal low cost
Solids carried in backwash Well demonstrated; O&M
water requirements
None Being demonstrated
? Experimental
-------
TABLE A-5
CENTRALIZED TREATMENT OPTIONS
Process
Chemical Precipita-
tion
Chemical Oxidation
Ion Exchange
Chemical
Adsorption
Level of
Process
Objectives Required Land
Solids and phos- High Low
phorus removal
Organic removal, High Low
odor control
N and metal High Low
removals
Solids and High Low
organic removal
CONSTRAINTS
Climate Operation Waste Stream Generated
None Chemical feed equipment; Increased sludge
Mixing, floculation and production
settling required;
Power may be required
None Handling of dangerous
chemicals;
Power required
None Media must be regen- Regenerate
erated;
Power required
None Media must be regen- Ash or regenerate
erated;
Comments
Well demonstrated; good for
phosphorus removal; help in
upgrading
Used only for special
application
More research need for
wastewater applications.
Susceptible to organic
fouling
Well demonstrated; used only
where extremely high quality
Power r equ i red
effluent is required
-------
TABLE A-6
CENTRALIZED EFFLUENT DISPOSAL
PROCESS
Disinfection
Halogens
Radiation
Ozone
Land Disposal
Land Application
Infiltration
Soil Absorption
(subsurface)
Evaporation Ponds
Surface Discharge
LEVEL OF PROCESS
CONTROL
Low - Mod.
High
High
Mod. - High
Low - Mod.
Low
LOW
Low
CONSTRAINTS
LAND
Low
Low
Low
High
Mod.
Mod.
High
Low
CONSTRUCTION
None
None
None
Sufficient depth to
ground water and bedrock;
high soil percolation
rates ; flat topography ;
holding lagoon outside
of flood plain
Sufficient depth to bed-
rock and groundwater;
high perk rates; out-
side of flood plain
Same as above
Sufficient depth to bed-
rock and groundwater;
low soil permeability
or lined
None
CLIMATE
Effectiveness varies
with temperature
None
None
Very sensitive to
climate; may be
limited to seasonal
operation
May require special
operation in winter
Generally none for
continental US
Very sensitive to
climate
None
OPERATION
Chemical handling difficul-
ties; over dosing can be
harmful to receiving waters
Requires thin film of
wastewater ; maintenance
or complex equipment
Maintenance of sophisticated
electrical and mechanical
equipment; on-site genera-
tion reduces chemical
handling problems
Vegetation management;
disinfection may be re-
quired
Disinfection may be re-
quired; alternating
beds
Minimal OSM
Odor and insect control
None
COMMENTS
Hell demonstrated; chlorine
as liquid or hypochlorites
is most commonly used .
Hell documented in non-
wastewater applications;
frequently not economically
competitive
Needs demonstration, particu-
larly for small flows
Hell demonstrated
Hell demonstrated; low cost;
low OSM
Hell demonstrated; land
above subsurface leach field
may be used for recreation
May use combination infiltra-
tion/evaporation
Demonstrated
U)
Ln
-------
TABLE A-7
SOLIDS STREAM TREATMENT OPTIONS
OPTION
Dewatering
Sand Drying Beds
Centrif ugation
Filtration (vacuum
or pressure)
Thickening
Stabilization
Chemical Oxidation
Chemical treatment
Lagoon
Aerobic or
anaerobic digestion
Composting
IMPACT
Reduction in wa.tej
content
Increase sol ids
content
Effective
Effective
Nay be effective
Effective
Effective
REQUIREMENTS
High land requirements
Energy costs
High energy, control, and
chemical requirements
Some energy required
Chemicals and power
Chemicals and power
Land
Process control and equipment
Land and bulking material
WASTE STREAM GENERATED
Dry sludge and supernatant
Dry sludge and supernatant
Dry sludge and supernatant
Supernatant and thickened
sludge
Stabilized sludge or sept age
for dewatering
Stabilized sludge or septage
for dewatering
Stabilized sludge or septage
for dewatering
Stabilized sludge or septage
for dewatering
Compost for marketing,
distribution
COMMENTS
Low cost but may require stabilized
sludges, long drying periods, and
cover .
Significant O&M requirements;
cht-mical conditioning required
Generally not recommended for small
communities because of process
control requirements
Often precedes dewatering
May constrain land application of
the sludge; demonstrated
Demonstrated
Demonstrated; odor and insect
problems
Demonstrated
Being demonstrated; dewatering re-
quired as a precursor; labor-
intensive
en
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TABLE A-8
DISPOSAL OF SOLIDS
OPTION
Landfill
Land Application
Market
(e.g. compost)
Incineration
PROCESS
CONTROLS REQUIRED
Leachate, runoff and cover
Application rate, runoff
control, crop and ground-
water monitoring
Market must be well established;
pricing, distribution and
regulatory structure may be
required
High energy and process control
LAND
AREA
low
mod..
mod.
CRITICAL
FACTORS
Careful site evaluation
required
Toxics and nutrient
loadings; pH. , soil
cation exchange
capacity, permeability
Same constraints as
application to land
Ash must be disposed of
,Air pollution require- ;
ments must be met
ADVANTAGES
Low cost; useful for most
solids
Uses materials as resources
Potential revenue generat.;
accomplishes resource
recovery
Not cost effective for
small communities
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APPENDIX B
COMMUNITY PROFILE SUMMARY, HILLTOWN
1.0 INTRODUCTION
The Hilltown Case Study area consists of. three unincorporated water districts
on the western slopes of a mountain range. Water Districts Number Two and
Three are adjacent communities in a valley, while Number One is located in a
neighboring watershed (Exhibit 1).*
1.1. GROWTH AND DEVELOPMENT
1.1.1 POPULATION AND ECONOMIC BASE
The results of a special 1978 census (Exhibit 2) indicate that the studied
area is predominently seasonal, single family residences. While only 35% of
the 3,010 housing units are permanently filled, the peak season occupancy of
these residences is 7,609 persons. Adding transient visitors and summer
students, the peak summer population could reach about 12,613, almost five
times the permanent population of 2,648 (Exhibit 3).
Previous to the 1978 census, all population figures were estimated from U.S.
Census data from a tract which contains several communities not included in the
study area (Exhibits 4 to 12). It is not surprising that the results of the
1978 census varied slightly from these estimates. The actual 1978 permanent
population is somewhat larger than the 1980 population predicted in the facili-
ties plan. However, the methodology used to determine the estimated rate of
growth is still valid and the projected saturation year-round population of
10,095 (Exhibit 13) may be reached somewhat earlier.
Both the facilities plan and the 1978 census show that the area's seasonal
population seems to be growing faster than its permanent one. Water district
Number Two has the largest percentage of permanent residents (40%) and unde-
veloped lots, while Number One has the smallest percentage of both. The over-
all permanent population density is about 2.55 persons per dwelling (Exhibit 13)
The economic base of the communities is quite sound. Despite the fact that
over half of the residents are over fifty years old and about a quarter
*In order to give a more concise narrative of the study area profile, all tables
figures, and supporting documents were located in an appendix to the Community
Profile. The exhibits have been omitted from this presentation. The objective
is to illustrate a community profile summary, not to provide complete information
about Hilltown. In this case, the supporting data presented in the various
exhibits was quite lengthy.
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of the principal wage earners are retired or unemployed, the average annual in-
come is about $13,600 (Exhibits 14 to 18). The primary sources of employment are
the various services provided for tourists and retired residents (Exhibit 19).
It is too early to assess the impact of the recently passed Proposition 13 on
the ability of such communities to provide services such as those proposed in
the 1978-1979 budget (Exhibits 20 to 22) .
1.1.2 LAND USE
Existing development consists of a commercial core area, surrounded by one
family mountain resort and general residential areas (Exhibits 23 to 28) . Over
98% of all dwelling units are single family houses, with mobile homes accounting
for about 60% of the remainder.
National forest, State park and other controlled developed areas lie beyond
these developed areas (Exhibit 29). Undeveloped and forest areas comprise over
60% of the study area.
1.2 NATURAL AND PHYSICAL FEATURES
1.2.1 CLIMATE
Generally, the area is hot and dry in the summer and wet in the winter, with
most of the average yearly precipitation of 24 inches occuring between November
and April (Exhibits 30 to 32). Consequently, during the summer peak water loads,
the rainfall is usually less than an inch per month and the streamflow lessens
or ceases.
1.2.2 SOILS, TOPOGRAPHY, AND HAZARDS
The main problem with soils data for the study area is that the agencies with an
interest in the subject either have not reviewed the area because it is remote,
unincorporated and non-agricultural, or have only highly generalized information.
Granite rocks which consist of undifferential granodibrite and tonalite underlie
the entire study area (Exhibit 33). When weathered, these rocks form a decom-
posed granite (residium) which is found mainly on the gentler slopes (Exhibit 34).
The soil text (Exhibits 35 to 36) summarizes the underlying area. Water
District Number One, at an elevation of about 6,100 feet, has thin topsoils
and deeper residium underneath with relatively good permeability. Water
District Number Two is similar except for its portion adjacent to the Creek.
This latter area is underlain by deep deposits of soil or extremely weathered
permeable residium that should have excellent percolation. Thf; Third Water
District soils, frcm colluvial deposits, similarly have excellent permeability.
As with the First District, the topsoils are thin. Together, these two districts
reach elevations from 4,900 to 6,400 feet.
The flatter areas on the western portion of Water District Number One and the
central eastern area of the Second District are underlain by ancient lake bed
deposits. The topsoils covering these deposits should possess good permeability
but a high water table frequently saturates the area.
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Ancient lacustrine deposits were also found in Saunders Meadow. This area is
underlain by porous organic silty sands for a depth of at least eight feet, and
like the faults is underlain by a shallow water table. Similarly, the areas
may have evolved from ancient landslides, producing a risk of reactivation from
remotely generated earthquakes. A fault 3.5 miles away from the area has a
recurrence interval of 100 years for producing seismic shaking of intensities
ranging from XII to XIII in the portion of the service area nearest to the fault.
While there are no official records on storms or floods, from past heavy rain,
water damage seemed most likely on low-lying parcels, especially on homes in
the floodplain by the Creek.
1.2.3 SURFACE AND GROUND WATER
The surface water in the Districts has varying degrees of contamination, while
the ground water is low in coliform bacteria (Exhibits 37 to 45). The Creek
begins relatively unpolluted in Water District Number Three. This District's
water supply comes from stream and spring diversions above the developed areas.
When this supply is not sufficient, seven wells are available for use.
The Creek then continues into Water District Number Two through the several com-
mercial districts, where it begins to show higher coliform bacteria levels. All
areas, except for the north and west areas of Water District Number One, drain
north to the Creek. After the Route 43 crossing and between a trailer park and
the USC campus, the Creek becomes swampy for a while. Around this area, there
are also animals nearby and tributaries from the flats and Water District Number
One. Water District Number Two still relies on a stream diversion, as well as
local wells, to obtain water. The First Water District, which is not located
adjacent to the stream, relies solely on wells (Exhibits 46 to 48).
1.3 EXISTING WASTEWATER DISPOSAL PROFILE
1.3.1 WATER CONSUMPTION
The water consumption for the year 1975-1976 was over 18,000,000 cubic feet
(Exhibit 49). The water requirements for Water District Number Two—the major
users—has dropped almost 40% since 1975, probably from user conservation. As
of 1976, the total well capacity for the three Districts was around 1,500 GPM
and Creek diversion rights 571 GPM from January to July (Exhibit 50).
1.3.2 ON-SITE RESIDENTIAL WASTEWATER DISPOSAL
In Improvement District Number 2A (Exhibit 51), there were 332 connections to
gravity sewers as of 1977. All other lots used on-site septic systems—including
150 housing units and numerous vacant lots in the Improvement District that chose
not to be connected. In 1961, records of septic tanks and sub-surface disposal
installations began to be recorded, and leach field and septic tank size
controlled by Health Department Standards. The previous facilities report
mentioned that some septic tanks installed before 1961 were pumped as often
as every two months, since some of the earliest systems were nothing more
than 55 gallon drums. About 887 septic tanks that are still in use were
built before 1961. Many of these systems are old and need some cleaning
and/or improving.
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1.3.3 EXISTING PUBLIC SEWERAGE FACILITIES
The public gravity sewer completed in 1970 is available to all the residents in
the Improvement District—even though some are still using septic tanks (Exhibit
52). Currently, this 0.2 mgd package sewage plant comprises a mixing zone, re-
creation zone, settling basin (clarifier), aerobic sludge digester and effluent
chlorine contact zone (Exhibits 53 to 54).
There is space available to add a second unit to the plant, which is located on
the western edge of the Second Water District. There has been no inflow/infil-
tration nor significant operational problems associated *with the plant facili-
ties (Exhibits 55 to 57).
Treated effluent from the facilities is transported under two miles to the efflu-
ent disposal ponds. These five ponds serve as evaporation/percolation ponds and
as a storage pond, from which pumps draw water that is disposed of by surface
irrigation in the adjacent hillsides. The buildup of biological solids at the
bottom of the ponds limits the percolation. Currently, the loss of water is
mainly due to irrigation and evaporation, not percolation.
1.4 EXISTING REGULATIONS AND INSTITUTIONS
1.4.1 REGULATORY CONSTRAINTS
There are discharge specifications for the existing treatment plant discharge to
the evaporation/percolation ponds and water supply, as well as effluent and water
supply monitoring guidelines (Exhibit 58). Similarly, the Wastewater Reclamation
Criteria (Exhibit 59) presents the water quality level needed for wastewater used
in various reclamation processes. In addition, sampling, reporting and reclama-
tion plant regulations are given as well as the reliability requirements for
uses permitting primary effluent.
The Septic Tank Ordinance (Exhibit 60) sets requirements for onsite waste-
water systems, including specifications for location, capacity, size, site
testing and installation.
The State Guidelines stipulating how surface water must be treated if used as a
water supply (Exhibit 61) are based on raw water quality data and other source
characteristics. Water Districts Numbers One and Three are defined as a Case I,
while Number Two is a Case II under these guidelines. It is in the best interest
of the community to prevent any degradation of their surface water supply sources
which would result in reclassification and thus greatly increased water supply
costs.
1.4.2 INSTITUTIONAL PROFILE
Currently, the water districts have set up one agency with the person in charge
of the Facilities Report having responsibility for water quality.
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APPENDIX C
GLOSSARY
201; Section 201 of P.L. 95-200, which details the construction grants program.
208; The area-wide wastewater management section of P.L. 92-500.
208 Agency; The planning agency responsible for completing and implementing
area-wide water quality management plans.
40 CFR 35; The chapter of the Code of Federal Regulations concerned with the
Construction Grants Program.
303e; River basic planning, required by Section 303e of P.L. 95-217.
701: Comprehensive community planning funded by the U.S. Department of Housing
& Urban Development under Section 701 of the Housing & Community Development
Act of 1956.
A-95; Mandatory intergovernmental review of Federal projects, established by
the Office of Management and Budget Circular A-95.
The Act: The 1977 Clean Water Act (P.L.95-217) which amended the Federal Water
Pollution Control Act of 1972 (P.L. 92-500).
Activated Sludge: A secondary treatment biological process used to remove
various components of the influent wastewater. This is included as a
conventional technology.
Alternative Technology: See section 2.2.2, page 13.
Ambient Water Quality; The existing stream or impoundment water quality.
Applicant: The local body authorized to apply for construction grants and
which will operate and maintain the proposed facility. The Applicant can be
a town, a county, a utility district, or a regional authority although it is
referred to as the municipality in the Act and regulations.
Aquifer; a geological formation of permeable rock, sand or gravel that serves
as a reservoir for groundwater.
Authorized Agent: The governmental subdivision which is authorized to represent
the applicant in the construction grants process, for example a Sewer Board.
In this manual the authorized agent is referred to as the Board.
Board; In this manual, the applicant's authorized agent.
Black Water; Wastewater generated from the toilet.
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CAC; Citizen's Advisory Committee, one form of public involvement.
Circular Reasoning; See proof by assumption.
Clearinghouse; See A-95. Besides the regional and state clearinghouse reviews
under A-95, this term may also mean the EPA Small Wastewater Flows Clearinghouse
established to provide a disemination point for information and research related
to technologies (see page 3).
COE; U.S. Army Corps of Engineers (Civil Projects)
Community: The group of persons within the service area who are in a position
to influence how and where services are provided. This group could include, in
addition to the officials of the Applicants Authorized Agent, other elected and
appointed officials, interested citizens, and special interest groups. In the
cases where a referendum or vote of town meeting is required, all eligible
voters are included in this group.
Coventional Technology; Proven systt-ms which are not alternative or innovative
(see 2.2.2) .
Cost-Effectiveness; A procedurespecified by the Construction Grants Program to
determine the most efficient alternative nlan (Appendix A of 40 CFR 35 pro-
vides guidelines).
Design Life; The period for which equipment or an entire facility can be
expected to perform adquately,
Design Period; The number of years for which the planned facility is expected
to provide service, generally twenty years under the construction grants program.
Developable; See section 5.1.1, page 74.
Developed; See section 5.1.1, page 74.
Discounting: The process of analyzing future costs and revenues to consider
the effects of interest and inflation, and make all dollar amounts comparable
on an equivalent basis.
EDA: Economic Development Administration, U.S. Department of Commerce.
Effluent; partially or fully treated wastewater flowing out of a treatment
facility.
EIS; Environmental' Impact Statements as required by the National Environmental
Policy Act.
Engineer: The registered engineer actually performing the work for the grantee.
While the engineer could be a staff member of the grantee, in small communities
a consultant is generally retained.
Evapotranspiration Systems; Systems which depend on evaporation and transpira-
tion (loss of water from plants) for wastewater disposal.
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FMHA: Farmers Home Administration, U.S. Department of Agriculture.
Generic Technologies; A term used in this manual to describe the group of tech-
nologies which use different methods to perform the same task.
Gravity Sewer; A collection system where gravity is used to transport waste-
water from the homes to a centralized treatment or disposal facility. Periodi-
cally the wastewater may be pumped to a higher elevation , but energy costs are
generally low since water flows downhill. Most gravity sewers are conventional
technologies; small diameter gravity sewers transporting septic tank effluent
qualify as alternative technology.
Greywater: All non-toilet household wastewater.
HUD: U.S. Department of Housing and Urban Development.
Hydraulic Overload: A condition when the quantity of wastewater flowing into
a facility exceeds its design capacity.
I/I; Inflow and Infiltration; a term used in the Construction Grants regula-
tions to identify water entering a wastewater collection system through damaged
pipes or illegal connections.
Indirect Impact: Another term for secondary impacts.
Infiltration: Seepage of a liquid through the solid soil. It may also refer
to the seepage of effluent into the ground to the aquifer or of ground water
into cracked or broken sewers.
Influent: Wastewater as received at a treatment facility.
Land Application: A method for distributing partially or fully treated waste-
water onto land where it receives further treatment by the soils and eventually
reaches the ground water. Land application can either be subsurface (leaching
fields) or surfp.ce (irrigation, landspreading with a truck, etc.). In some
cases, land treatment may be used as a treatment step alone, with underdrains
to collect the effluent for disposal elsewhere. Generally considered alterna-
tive or innovative.
Leaching Fields; The most commonly used on-site disposal technique consisting
of tiles which distribute septic tank effluent for subsurface land application.
This is a type of soil absorption system.
Lagoon/Stabilization Pond: An impoundment designed to enhance the natural
purification of wastewater without major input of energy by allowing enough
time and mi:-:in^ for biologic activity.
Natural Resource Limitation Areas; Land which is particularly sensitive to
development, such as steep hillsides, wetlands and floodplans. Also referred
to as sensitive areas.
Non-Degradation; A water quality classification used to denote a water body
to which no pollutants may be legally added.
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NPDES; National Pollutant Discharge Elimination System which requires that all
treatment plants discharging into surface waters obtain a permit from the U.S.
Environmental Protection Agency specifying effluent quality.
O&M; Operation and maintenance of a wastewater facility.
On-Site System; A self-contained system which provides both treatment and
disposal of wastewater on an individual lot.
On-Site Management District; A public entity authorized to operate and control
public or privately-owned on-site systems.
Potable; Drinkable.
Pre-Application: The phase of the Grants Program where the Grantee—frequently
with the assistance of a consulting engineer—prepares an application for Step 1
grant funds.
Present Worth; An estimate of the amount of money which would now equal all
future costs of the wastewater system. It is the sum of all construction and
O&M costs for the design period, discounted to the present.
Pressure Sewers; A collection system in which wastewater is pumped under pres-
sure frcm homes into a pressurized main and conveyed to an existing collection
system or directly to treatment/disposal. Grinder pump pressure sewer systems use
individual grinder pumps to pump raw sewage from each home. STEP systems utilize
simpler pump to convey septic tank effluent.
Priority List; An annual state ranking of projects, which is developed by
consideration of the severity of current problems, and used to decide which
projects receive funding.
Proof By Assumption; See circular reasoning.
Public Hearing; An open meeting held by the grant applicant to obtain formal
comments on a plan. Notification of the public through newspaper and other
media advertisements is required. A transcript of the hearing is maintained.
Public Meeting: An informal meeting frequently used as a means to develop
public participation in a program. No legal record of the meeting is necessary.
Public Participation; A program required by the construction grants program
to insure that citizens have been consulted and informed throughout the
planning process.
Receiving Waters; Streams into which treated wastewater is discharged.
Reserve Capacity: Capacity included in facilities above that needed to serve
current connections, accommodate future growth. Excessive levels of reserve
capacity are not eligible for Construction Grants.
Residuals; The by-products of wastewat«r treatment processes. These include
sewage sludge, septage, and waste liquid flows from dewatering operations as
well as emissions to the air.
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Reviewers; State and/or EPA staff responsible for administering the Grants
Program in each state. This responsibility includes review of grant applica-
tions, facilities plans, and facilities designs, plus supervision of construc-
tion.
Rural States: States which are required by the construction grants program to
set aside 4% of their allotment for funding of innovative and alternative tech-
nologies in rural areas. These states have a rural population of 25% or
greater:
Alabama Kentucky New Hampshire South Dakota
Alaska Louisianna New Mexico Tennessee
Arkansas Maine North Carolina Vermont
Delaware Michigan North Dakota Virginia
Georgia Minnesota Oklahoma Washington
Idaho Missouri Oregon West Virginia
Indiana Mississippi Pennsylvania Wisconsin
Iowa Montana South Carolina Wyoming
Kansas Nebraska
Salvage Value: The anticipated value of any portion of a facility, including
the land, at the end of the design period,
SCS; Soil Conservation Service, U.S. Department of Agriculture.
Secondary Impacts: Effects of a project arising through induced changes in
population, economic growth and land use, and the environmental effects result-
ing from these changes.
Sensitive Areas; See Natural Resources Limitation Areas.
Septage; The solid and liquid material removed from a septic tank during
pumping.
Service Area; The geographical area in which the Grantee is responsible for
providing wastewater management services.
Sludge: The precipitated solid matter produced in the sewage treatment
process. (2-5% solids, 95-98% water)
Soil Absorption System (SAS); A subsurface land application system for waste-
water disposal (e.g., a leach field).
Spray Irrigation System; A method of land application in which effluent is
sprayed over agricultural fields.
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Step I: Facilities planning grants for the study of wastewater management
options and the selection of the most cost-effective level and type of treat-
ment.
Step II: Facilities grants for the design of the most cost-effective
alternative as determined by the Step I process. During this phase plans and
specifications for the new facilities and/or management program are developed.
Step III; Grants for the implementation of the plans designed in Step II. This
generally includes the construction of facilities.
Surficial: Of or relating to the surface.
Time Staging: Scheduling construction of phases of a project over time to meet
future demands for service.
Trickling Filters: A fixed film biological wastewater treatment process
capable of producing an effluent of secondary standard quality; one of
several conventional processes for treatment of wastewater.
Unconfined Aquifer: A ground water reservoir which is continually recharged by
water seeping through the soil from the surface. Also known as a water table
aquifer.
Undevelopable: See section 5.1.1, page 74.
Uniform Plumbing Code: A code of practice frequently adopted by state regula-
tory authorities as the basis of building codes.
U.S.F.S.: United States Forest Service, U.S. Department of Agriculture
U.S.G.S.: United States Geological Survey, U.S. Department of the Interior.
Water Table Aquifer: See unconfined aquifer.
Waste Load Allocations: The maximum amount of a given substance that a surface
water body can receive. Discharges will be issued a permit for only a portion
of the theoretically acceptable waste load, as set by the state in the 303e
plan.
Wetlands: Low lying lands which frequently have standing water on them such
as swamps, marshes, and meadows; see natural resource limitation areas.
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
REPORT NO.
EPA-600/8-80-030
3. RECIPIENT'S ACCESSION NO.
TITLE AND SUBTITLE
5. REPORT DATE
Planning Wastewater Management Facilities for
Small Communities
6. PERFORMING ORGANIZATION CODE
August 1980 (Issuing Date)
AUTHOR(S)
Patricia L. Deese and James F. Hudson
8. PERFORMING ORGANIZATION REPORT NO.
PERFORMING ORGANIZATION NAME AND ADDRESS
Urban Systems Research and Engineering, Incorporated
36 Boylston Street
Coston, Massachusetts 02138
10. PROGRAM ELEMENT NO.
35B1C
11. CONTRACT/GRANT NO.
68-03-2614
2. SPONSORING AGENCY NAME AND ADDRESS
Municipal Environmental Research Laboratory—Gin. ,OH
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
13. TYPE OF REPORT AND PERIOD COVERED
Final 9/77-6/79
14. SPONSORING AGENCY CODE
EPA/600/14
5. SUPPLEMENTARY NOTES
Project Officer: Robert P. G. Bowker (513) 604-7620
6. ABSTRACT
This manual presents a set of procedures for planning wastewater management
facilities for small communities and is directed at areas with populations of
under 10,000. It is designed to aid engineers and the communities they serve in
evaluating various options for treatment and disposal of wastewater, which range
from septic tanks and on-site disposal fields to conventional gravity sewers and
centralized treatment plants. Information and techniques are presented for
recognizing and evaluating wastewater management problems frequently faced by
small communities and for planning the range of facilities which will solve those
problems, giving due consideration to costs, community characteristics, and growth
management.
Part 1 of the manual was prepared to give an overview of the planning process
and the regulatory context under which it fits and is likely to be useful for
local officials, concerned citizens, and engineers active in wastewater planning.
Part 2 is a technical reference, showing the details of the planning process with
examples from case studies.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
Community planning
Town planning
Waste treatment
Waste water
Wastewater facilities
planning small
communities
13B
18. DISTRIBUTION STATEMENT
Release to public
19. SECURITY CLASS (ThisReport)
Unclassified
21. NO. OF PAGES
158
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2220-1 (Rev. 4-77}
148
»US GOVERNMENT PRINTING OFFICE 19SQ-&57-165/0088
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