Onsite Waste water
Disposal Alternatives-
A Methodology for Evaluation
A Case History in 208 Water Quality Management Planning
1
^-rrr?rT:i:"^^snf^*^fcS
-------
-------
EPA-440/3-77-021
March 1978
ONSITE WASTEWATER
DISPOSAL ALTERNATIVES
A METHODOLOGY FOR EVALUATION
\
UJ
CD
U.S. ENVIRONMENTAL PROTECTION AGENCY
* Environmental Research Information Center* Technology Transfer
* Office of Water Planning and Standards Water Planning Division (WH 554)
401 "M" St. S.W., Washington, D.C. 20460
-------
ACKNOWLEDGEMENTS
This publication contains information prepared for the U.S. En-
vironmental Protection Agency, Environmental Research Informa-
tion Center, Office of Research anq: Development; and Water Plan-
ning Division, Office of Water Planning and Standards.
The information in this publication was prepared by Wiggins-
Rimer & Associates, Durham, North Carolina. The case history was
authored by Mr. Alan E. Rimer, P.E., with the assistance of Mr.
Roger N. Schecter, AIP. Also providing assistance was Ms. Susan K.
Wilkes, Water Quality Project Manager for the Old Colony Planning
Council
NOTICE
This publication has been reviewed by the Environmental Research Information Center and the
Water Planning Division, Office of Water Planning and Standards, U.S. Environmental Protection
Agency, and is approved for publication. Approval does not signify that the contents necessarily
reflect the views and policies of the U.S. Environmental Protection Agency, nor does any mention
of trade names or commercial products constitute endorsement or recommendation for use.
11
-------
OIMSITE WASTEWATER DISPOSAL ALTERNATIVES
A METHODOLOGY FOR EVALUATION
INTRODUCTION
Subsurface wastewater disposal problems
were identified by the Old Colony Planning
Council (OCPC) in southeastern Massachusetts
as one of the major issues to be resolved in
their areawide planning program. OCPC
therefore decided to develop a methodology i
for evaluating onsite disposal systems in their
region. Evaluations involved defining and
analyzing the causes of failures in existing sub- ;
surface disposal systems. Once the method- ;
ology was developed, it was applied to
establishing criteria for evaluating onsite -
disposal alternatives. Such criteria were useful
in coordinating design .and maintenance of on-
site disposal systems with other alternatives
such as sewers. In the future, a thorough eval- ,
uation of the various alternatives can be made
with some certainty that equal consideration
will be given to onsite disposal alternatives. :
OCPC's onsite disposal survey and the sub-
sequent evaluation of alternatives shifted
emphasis in the Region from an automatic
assumption that sewers were necessary, to a \
more careful evaluation of onsite disposal
systems. At least one community that was to
be part of a regional wastewater treatment >
facility concluded that onsite disposal facilities
were more feasible and elected to withdraw :
from the regional wastewater treatment plant j
(WWTP) plan suggested by the 201 Facilities i
Plan. One other community that was not part
of the regional WWTP facility has been recom-
mended by OCPC as a potential member.
OCPC has also been active in holding work- i
shops to educate the public and local govern- !
ment employees about subsurface disposal
systems and their general reliability with pro-
per maintenance. As a result of this effort, ex- ',
penditures for sewers have been reduced and
a more cost-effective solution of onsite disposal
has been selected for some of the involved
communities. Ultimately the waters of the
area will be protected and the communities
have been assured of a reliable, least-cost solu-
tion to their wastewater disposal problems.
The OCPC was formed in 1967 as the
regional planning agency for 13 communities
in southeastern Massachusetts (Figure 1).
The OCPC Planning Region contains one
major city, Brockton; several urbanized com-
munities such as Avon, Abington, and Whit-
man; and a number of less developed com-
munities such as Easton, the Bridgewaters,
Hanson, and Pembroke. The 1975 population
of the region was approximately 193,700, with
nearly 50 percent of the residents living in
Brockton. Land use in the region varies con-
siderably from highly urbanized downtown
and industrial areas in Brockton to the rural
and recreation-oriented areas in the Bridge-
waters and Plymouth. Though the region was
traditionally dominated by nonurban use, the
influence of Boston, approximately 20 miles
to the north, has had an impact on develop-
ment patterns. According to a Census Bureau
survey, about 40 percent of the work force in
the region currently commutes to the Greater
Boston area.
As a result of development in the Boston
metropolitan area, growth in the Old Colony
Planning Region is expected to continue. The
population of the region through the year 1995
is projected to be 247,600.
The water resources of the area, which are
dominated by numerous ponds, substantial.
wetlands, and the drainage area of the Taunton
-------
Old Colony
Planning District
Figure 1. The Old Colony Planning Council District.
River, provide the major water supply for the
communities in the planning region. Three com-
munities rely on surface water supplies, six
depend on groundwater supplies, and one re-
lies on a combination of both. Of concern to
the OCPC was the potential for pollution of
these water resources from either onsite or
centralized wastewater disposal facilities.
With the growth of an area comes the
inevitable pressure for construction of sewers
and a wastewater treatment facility. Such
facilities are often viewed as the only method
by which a community can provide adequate
wastewater treatment. Sewers and wastewater
treatment facilities have high capital costs and
pose the continuing burden of operation and
maintenance costs. Sewers also have potential
secondary impacts that concern many commu-
nities, including increased land use resulting
from induced population growth.
Except for the City of Brockton, the older
section of Bridgewater, and a small portion of
Abington, the Old Colony planning area de-
pends on onsite disposal systems for waste-
water treatment. Because of rapid growth in
the past 20 years and because of the develop-
ment that has occurred in areas with soils
marginally suited for onsite disposal, nearly all
communities in the planning area have experi-
enced failures of subsurface disposal systems.
Many of these failures have directly affected
local water quality conditions and have been
documented by the OCPC in extensive studies.
When the Old Colony areawide planning pro-
gram was developed, it immediately recognized
the need to examine very carefully alternative
solutions to centralized sewer systems. Means
were examined for developing a comprehensive
plan to improve water quality in the area and,
potentially, to reduce secondary impacts from
the development of sewers. A plan was then
established to determine sewerage needs
for the area communities. Public conferences,
detailed literature searches, and outside con-
sultants were used to determine the need for
public sewerage as opposed to onsite disposal
and then to identify feasible alternatives to
public sewers. The OCPC then used their
findings to begin control of existing and po-
tential problems in their planning area.
-------
THE OCPC ON-LOT DISPOSAL SURVEY
As communities grow, requests for the in-
stallation of a public sewerage system generally
increase. The "pro-sewer" bias contends that ;
such a system will automatically make a com-
munity modern and enable it to grow. Such
feelings regarding the inevitable construction
of sewers were demonstrated in several engi-
neering reports completed for OCPC member
governments. One report stated, for example,
that
"Eventually the percolation proper-
ties of the soil at the leaching field
will become exhausted. Under
favorable circumstances, an on-lot
system can provide satisfactory ;
service for 10, 15, or 20 or more
years, after which time it is neces-
sary to reconstruct the leaching
system at another site." ;
In another similar report, it was stated that
"a service life of 15 or 20 years was
not unusual for a subsurface disposal
system and that a municipal sewerage
system was therefore an eventuality
in most communities."
By implication, sewers would be inevitable for
most communities because septic tanks would
last for only 15 to 20 years! This assumption
is contrary to published data.
System operation plays a very significant ;
role in determining the long-range suitability
for onsite disposal systems. If new construc-
tion is controlled so that the systems are
designed, installed, and operated properly, and
provided with suitable preventive maintenance;
then subsurface disposal systems in most areas \
can be made to last for more than 30 years. '
The OCPC was able to examine closely most
of the important factors associated with the
design, construction, and maintenance of sub- -:
surface disposal systems and, therefore, to
permit a balanced comparison of onsite systems
with sewerage alternatives. They set out to
examine each community in the planning
district and to seek answers to the following ;
questions:
How extensive are the areas of subsurface
disposal failure?
Is a public sewerage system necessarily the
most cost-effective and environmentally
sound solution to the water quality prob-
lems caused by the failing systems?
Though these questions imply an anti-treat-
ment-plant bias, they were based on the
reactions of area residents who felt strongly
that a central wastewater treatment plant was
not the only answer to wastewater disposal.
The above questions suggest several assump-
tions that were considered.
» A public investment in sewers should be
made only where public health and water
quality problems are caused by failing on-
lot systems or where failure is likely to
occur as a result of increased growth.
Public investments should not be made in
those areas that serve only industries and
, would have no public health or other
water quality benefits.
Public sewers are not necessarily the most
cost-effective solution or the most environ-
mentally sound solution for wastewater
disposal.
DETERMINING EXISTING ON-LOT
DISPOSAL PRACTICES !
The Old Colony areawide planning program
implemented a rigorous methodology to deter-
mine existing onsite disposal problems. The
first step was to establish just what constituted
a failure or problem in regard to onsite systems.
After examining many failures, the problems
were divided into two types: (a) septic systems
that caused water quality problems, and
(b) septic systems that had some degree of
operational problem.
The OCPC recognized that though definitions
of onsite disposal problems may vary around
the country, an adequate data collection effort
is required by any region before reaching con-
clusions about the acceptability of onsite
disposal systems. Several ways to collect infor-
mation on the onsite disposal systems in the
area were examined. Initially, the 1 >cal board
of health in each community was contacted;
-------
Septage
hauler
questionnaire
1
Water
quality
data
State
data
files
1 1
Land/use
soils
information
Local board
of health
questionnaire
J
Determination
of likely
problem areas
Windshield
survey
Residential
questionnaires
Defined
problem
areas
1
Confirmation
of problem areas
with health boards
Figure 2. Data collection methology for onsite disposal system failure areas.
but a decision was soon made not to rely solely
on information available from this source. It
was reasoned that many homeowners might
have been reluctant to make their problems
known to the board of health for fear that they
they might incur large costs for replacing
their systems. Figure 2 shows the general ap-
proach used by OCPC to collect information
on failing systems in the area and thus to iden-
tify areas prone to failure. The initial data
sources utilized for screening existing and po-
tential problem areas included the following:
Septage haulers questionnaire. A ques-
tionnaire was sent to haulers serving each
community. Included with the question-
naire was a map of the community on
which the hauler was asked to identify
areas where homes required frequent
pumping.
Land use/soils information. - The OCPC
compiled existing land use information
for each community in eight categories
(single and multi-family residential, com-
mercial, industrial, public land, agricul-
tural land, utilities, and vacant land).
After this information was compiled on
a base map for each community, soil
suitability maps prepared by the U.S.
Soil Conservation Service were used as
overlays. Areas with dense development
on marginal or unsuitable land for onsite
disposal were considered potential areas
of subsurface system failures.
Board of Health questionnaire. - Each
local Board of Health was sent a question-
naire and a local map on which they were
asked to indicate areas of the community
where homes had onsite sewage disposal
problems.
State department of environmental
health. - The complaint file for subsur-
face disposal problems was examined.
-------
Water quality data. As part of the area-
wide planning effort, an intense water
quality sampling program was initiated ;
during two 2-month segments of the year,
and 69 surface and groundwater sites were
sampled. The sites were distributed over ,
the entire planning area. Parameters
used to determine the presence of
subsurface disposal leachate included total
and fecal coliform, fecal strep, ammonia, ;
nitrate, and phosphorus.
From this five-stage data collection proce-
dure, various areas within each community in
the planning area were identified either as hav-
ing a high potential for subsurface disposal
failures or as actually experiencing problems.
Once problem areas were defined, it Was neces-
sary to obtain more specific information about
potential and actual failures in the identified
areas.
Another approach to more positive defini-
tion of existing problem areas included the :
distribution of questionnaires to all homes in
the identified areas. The one-page question-
naire asked the following:
Number of bedrooms :
Type of wastewater disposal system :
Problems experienced
Times that problems occur j
Average annual maintenance costs i
Awareness of problems with neighbors'
systems
After the survey information from residen-
tial areas was compiled and problem areas were
defined with OCPC criteria, the identified prob-
lem areas were reconfirmed with the respective
boards of health as the final step in the process.
Once the problem areas for each community
were defined, they were plotted on a map and
examined as to how pervasive the problem was ;
in a particular community. Determination was
also made as to whether rehabilitation or com-
plete reconstruction (such as a mound system
or location of the system at a remote site)
would be required. Such factors were then
used to evaluate alternatives available to the
community. :
This methodology worked quite well with
respect to the identification of problem areas,
but it was inconclusive in two respects:
a) determination of the severity of subsurface
disposal problems, and b) identification of the
specific cause of the problem. Thus the meth-
odology was useful for eliminating areas from
consideration and assisted in pinpointing
specific problem areas, but it could not be site
specific as to cause and effect.
As a result of this study, it was concluded
that in the future the survey should consider
the following:
The reliability of each data source should
be considered very carefully and evalu-
ated along with other available data.
Water quality data must be interpreted
carefully. They can: generally be used to
isolate problem areas, but they may PC'
be good for identification of site-spc -"c
locations. Fecal strep data should bt ?d
to differentiate human from animal
waste sources.
Once major problem areas have been
identified, additional work should be done
to determine the specific cause of the
problem (poor siting, installation, or
maintenance, etc.). This information
might be gathered by either site-specific
visits or more detailed questionnaires.
CONSIDERATION OF FUTURE WASTE
DISPOSAL NEEDS
Many factors must be considered when
evaluating community use of onsite disposal
systems for periods of up to 20 years.
i
Population projection factors such as
zoning, lot sizes, and land available for
development
System operation factors such as mainte-
nance and regulations enforcement
Water quality factors resulting from
intensive land use.
Population projections are essential to esti-
mating future needs. They can be based on
-------
the available developable land in a community
and on current zoning. Such a comparison of
population and land could indicate the satura-
tion population for a community, but it also
raises several less tangible questions. For
example, should the projection be based on
known soils limitations, or should sewers be
used to accommodate the growth that might
not take place otherwise? How should sewers
be used as a tool for channeling growth within
a metropolitan area? These questions are
numerous, and the OCPC concluded that such
value judgments should be made by the com-
munity. Some communities might be more
willing to grow than others, but planners and
engineers should factor these desires into
their projections.
Plans for the future must also consider exist-
ing septic systems. Generally, little informa-
tion is available on the installation, construc-
tion, operation, and maintenance of older sys-
tems. Incomplete building and septic system
permits are often the only data available. One
must therefore determine how many systems
currently in place might fail. A partial answer
to this question can be found in the data from
the OCPC survey.
Water quality is another important consider-
ation. In New England, water recreation on
small manmade and natural lakes is quite
important. Thus any degradation of water
quality resulting from subsurface system
features is a cause for real concern, as is any
policy that permits such a situation to continue.
The intense use of subsurface disposal systems
and their eventual impact on water quality can
be measured, but they must be carefully
weighed in light of the various alternatives
available.
MANAGEMENT OF SUBSURFACE
DISPOSAL SYSTEMS TO INSURE
LONG-TERM USE
If onsite systems are selected, how does a
community ensure that the system will continue
to be successful? Old Colony believes that sys-
tem maintenance is the key. Figure 3 illustrates
the major components of such a maintenance
system. Failure in any of the areas shown
increases the likelihood of problems. Manage-
ment components must be fully integrated and
regulated by one agency, either at the local or
regional level; but such agencies exist in very
few locations.
The Role of Design
Research into the design of subsurface
disposal systems turned up considerable vari-
ances in design parameters throughout the
country. The reason is that local or county
health departments generally have regulatory
power over onsite sewage disposal, and there is
a variety of State and local relationships. In
Massachusetts, for example, the State auto-
matically assumes responsibility for all sub-
surface disposal systems over 57 M^ (15,000
gpd) and can modify local ordinances to con-.
form to the State code for smaller systems.
Subsurface system
maintenance components
Good
system
design
Plan
review
Installation
inspection
Ongoing
system
maintenance
Figure 3. Subsurface disposal system maintenance program.
-------
The variability in design regulations among
the States concerning tank sizing, depth to
water table, distance to water courses, and
percolation testing must be evaluated on the
basis of local conditions. Based on the data
collected, Old Colony concluded that one of
the more important design factors was the
construction of a pit for percolation tests.
Percolation testing is an area where a standard-
ized procedure could be used to insure con-
sistent practice and some measure of correlation
between results from different areas. Variations
in design of conventional septic systems also
reflect disagreements as to how the system
works. Local experience, not systematic
research and study,"1 often dictates the standards
used for construction of the percolation pit.
Results can be deceptive, because poor mainte-
nance practices often cause a properly designed
system to fail.
Based on Old Colony's experience, member
communities were urged to examine carefully ;
the design practices used in their area and to
base the recommendations for design (and :
particularly percolation testing) on a more
systematic understanding of the process.
Another design factor noted during the
needs survey was that many of the systems
that are now failing were in fact cesspools.
Cesspools were not prohibited by the State
Sanitary Code until 1962, and enforcement of
this prohibition was often delayed until the i
late 1960's:. ;
Siting is another factor that directly affects
system design. Common sense dictates that ;
future subsurface disposal problems can be
minimized by simply avoiding areas where
there are unsuitable soils, high water tables, or
other potential water quality problems. '
The OCPC also set about to dispel the myth
that a large .4 to .8 hectares (1 or 2 acre) lot
size is necessary to support a subsurface
disposal system. It was demonstrated that a '
two-bedroom house with four inhabitants and
a garbage grinder, built on the worst soils :
acceptable to the Massachusetts Environmental
Code (based on percolation test results) would
require approximately 93 to 112 square meters
(1,000 to 1,200 square feet) for the septic tank
and leaching field. With an average house of
158 square meters (1,700 square feet), a home
could be built on a 930 square meter (10,000-
square-foot) lot, given other zoning bylaw
set-back restrictions. Claims that an absolute
minimum of 3720 square meters (40,000
square feet) were required to avoid septic fail-
ures were not found to be valid. But the use
of a smaller lot assumes that soils are suitable
for installation of an onsite system. OCPC
concluded that to minimize water quality
problems, lot size and other 'siting controls
should be essential design components in a
nonsewered alternative.
Plan Review and Installation
Two more important considerations in sub-
surface disposal system maintenance are plan
reviews for new construction and subsequent
installation/inspection procedures. These two
components of the subsurface disposal system
maintenance program are synergistic. In their
work plan, OCPC examined planning methods
and evaluated inspection procedures used
during installation. For example, health agents
in the planning area cited poor construction
procedures were used when developers installed
septic tanks over a short period of time
throughout a subdivision. Listed, below are
procedure developments that should be care-
fully controlled to insure that the leaching
field will function properly:
Plan review:
Review plans for compliance with statutes
Check soil characteristics
-Witness percolation tests
Review water saving measures
Inspection program:
Inspect construction in three, stages:
a) Before installation of'stone in the
trench :
b) Before backfilling and after all installa-
tion is complete
c) After backfilling
-------
Insure that leaching field is properly sloped
Insure proper conformance to original
design.
OCPC found that the review of plans, wit-
nessing of percolation tests, and construction
inspections required during installation takes
time and expertise commodities that many
of their member communities did not have.
Some recommendations for relieving the
inspection problem by funding a staff member
to perform the noted duties are as follows:
Hire a full-time health agent and increase
installation permit fees to help cover the
costs.
Where appropriate, and when funds are
unavailable, consider the services of a
full-time health agent for two or more
towns.
Have on retainer a professional environ-
mental or civil engineer to serve as a
representative and agent of the local
board of health. His services could be
paid directly by increased fees from the
developer or homeowner.
When a subdivision is constructed, have
the developer's design engineer (licensed
by the State for subsurface disposal
system design, installation, and inspec-
tion) certify that the construction was
done in compliance with regulations.
Each community will have its own manage-
ment system based on local regulations although
it should be consistent with state regulations.
It was concluded, however, that local authori-
ties should regulate local onsite sewage disposal
and it should not be a state function.
System Preventive Maintenance
Evaluations of communities within the plan-
ning area showed that the regulation of septic
tank system management by the public
authorities extended only to design regula-
tions, plan review, and installation inspection.
In no case had any community extended its
regulatory programs to maintenance after the
system had been installed.
One of the most prevalent causes of septic
tank failure is poor maintenance. People may
be unaware of the subsurface disposal system
they have, and they are frequently unaware of
how to deal with it. OCPC found that most
homeowners simply did not understand the
workings of their septic tank or how to main-
tain it. They concluded that maintenance was
one of the more important issues to be
addressed if onsite systems were to be con-
sidered as serious permanent wastewater
disposal options in 208 planning.
The OCPC also recognized that maintenance
should begin with water conservation, and not
just consider septic tank pumpouts. Since a
subsurface disposal system should be per-
ceived as a system, everything from inhouse
appliances to the soil structure below the
absorption field is important. It was concluded
that there were four elements in areawide plan-
ning that should be considered when establish-
ing a system maintenance program: (1) waste-
water reduction, (2) waste segregation,
(3) septage removal, and (4) leaching field
alternation.
Wastewater Reduction
Per capita water consumption in this country
is generally quite high, and thus most sanitary
codes require that subsurface disposal systems
be designed to accommodate such flows.
Reduced water consumption is a desirable sys-
tem maintenance practice. If it were prudently
employed, OCPC concluded that a substantial
reduction in water to be treated in the system
could be made without seriously affecting the
life style of the user. Reduced volume to be
treated should increase system efficiency and
ultimately permit the design of smaller
systems.
OCPC determined that two primary areas
for domestic water consumption reductions in
the typical household are toilets and shower-
heads. Figure 4 illustrates the impact of modi-
fying just those units.
Waste Segregation
Homeowners need to understand what types
of waste should be kept out of the septic sys-
tem to insure long-term maintenance of the
8
-------
50 _
.t;
o.
Water reaching
subsurface
disposal
Without water
saving devices
With water
saving devices
Water consumed
Flushing toilets
Showering & bathing
Note: Based on average daily use of 50 gallons/capita/day
Figure 4. Water reduction impacts ,on wastewater flows to subsurface system.
system. A particular problem is with kitchen ;
. grease, which is often discharged down the sink
drain rather than placed in the garbage. Home-
owners who have subsurface disposal systems
should be discouraged from installing garbage
grinders. A homeowner's maintenance book-
let should be distributed to detail the types of
waste that should be kept out of the system.
Septage Removal
One of the most common causes of system
failure is clogging of the absorption field by
solids that escape from the septic tank. Solids
should be pumped out periodically. Many
homeowners are unaware that sludge builds up
in the septic tank and have no idea that they
have a problem until the system fails. Various
means exist to insure septage removal, but
there is some question about the period of
time that should elapse between pumpings.
Every areawide planning agency must consider
what is required for its particular situation.
OCPC has concluded, however, that pumping/
inspection are beneficial and should be done
on a regular basis (about once every year). A
number of different approaches can be taken:
Passive approach a postcard reminder
every 3 years to have the system pumped.
Active approach subsurface disposal
systems owned and operated by a public
sanitary district.
Active approach the local board of
health or county could issue a subsurface
disposal permit that requires renewal
every 3 years and proof of pumping
before renewal. :
Leaching Field Alternation
OCPC determined that alternating absorption
fields during the course of normal operation is
a particularly beneficial practice for septic sys-
tem longevity. If the field is rested for a period
of time, its ability to regain of maintain its
absorptive capacity is enhanced.
IMPLEMENTATION OF FINDINGS
After the information on problem areas was
reviewed by each local board of health, the
-------
C"
E
RJ
a>
**
5,
CO
"a
CO
rf
jto
"«
-C
S * t! IS -
QC O cn*O
4J Q, OJ QJ
a. « -o *->
J« C*3 S 5
u o cr ia C
U 4J !^ (/> OL
jd i.
0 01 O *»
t. CuXZ +* O
24-1 >r« "O
o z &- in
*-^ o Oi ui
'r-j QJ C C
O> C fO CL
Blsil
"o
a
CO
co
Q>
O
in o *J ra c
*" U QJ QJ JE
QJ oj in c in o
S in QJ +J ra
OJ *r~ cn S- L.
in x: ra o 01
4-» 3fe o. c x:
r~ en in -o
o c -i- m o
XT *r- QJ 3 ^D +J
^ t ^ o-^ ^
x: o QJ
x: QJ »+-
r ui ui 4^ x:
ra ra c E c:
x: c: J- o *->
(J QJ O *4-
r- QJ CL S« O
x: t. E OJ o *»-
C i- 4-> QJ
*r- O -O (0 3 in
4-» *f- OL O
X QJ XI 0)
XJ C U> 4-»
o o QJ e I-
1 -0 O4-> X> E
L. QJ m T- QJ
OJ t- QJ OJ J£ 3 4J
+» o E > c: cr in
2 in in x: +J ZJ ui
o
Q.C
05 CCS
COh-
QJ QJ
Q. C ,
o
M- 4-> 1
o in ,
u
in T3 i
L. co v
QJ (0 0
O
U)
in -o
QJ QJ
r XI
O =
c:
|I .*
30 c
.^^ .CD
°-JB r-
O) O ^^
4J C CJ
(U (I) «^
S- i- *-
g^ Q.
0 c 41%
(J -r- W
o«, CO
O* O)
s- Q- ^i^
ra - UJ
~J °~ <
b> H
II
CO CO
CD ><
-Jtyj
kis
:p|
U1C b
8*1
.-Is
0
n"
'
1
* <
X
«u
;
i.
s=>
<
t £5
za: '
II
l-Lpl , fe
3 ^ /-V^j'
a /'-vrv-i
N!-. . p:
il | 11 £:
d \ ? te '«5
5 ) 11 "
' 1>^ pi o
43^ r .C
O
Q
1
c
2
cu
5
1
0
CL
CU
(/I
x;
4-1
F SOLIDS ir
0
Q ^
_J O
UJ t
EXCESSIV!
overfloi
cu
c
rO
J_
o
'oi
>
i/) O
cu c
c
+J ro
C 1
Q. Q.
QJ
4- 1
£1 O
|g
1^
1 H
Cfl
_;
0 <
D- U
0
i_
^
O
- i_
0)
jroundwat
o
i a!
CT> .
S.^~'£
O o t
M i.
O
a.
o
cu
Ol
Is
. 12
.1 i
£ a_
° CO
(0 CC
C71 LLJ
c o:
.c UJ
u x
SS
_j 3-
cu O
"~ o
CO >-
0 0
0 Q
ce
c
OJ
u
i-
c
s s
o
+J O
Q.
CU 13
C CO
C -C
0 -M
|3
r- in
s s
(O i
1- O
o s_
cu
11
c
CU -*
U O
** o
fO Q)
C
o
u
C t/I
1- C
15
^ '
U Q.
CL QJ
P 5J H
Si!
cu
I
0)
o
o
o
^
e
Q)
3
I
Si
CU
* **-
= g-
QJ in o
in 4->
ra OJ in
*** o 4J en
k» >>..==!
»r- g XT
O 3 Ci
*O O
,1
QJ ra
ra i
,-.^ g.4^x: >,£ al
>«~ *j & u ra ra Qi
4J o. 5 c ra m cn-t-»
£
0)
0.
(0
O
I
S3
fig"
= 1-8
Ulg, , .
iz'i^j
i O in ra
t i in j
Ml:
UJ * °
c
a> S
> t.
S "S
>, . S-.S-
QJ C -f- CL
x: o x:
H- 'f- O T3
4J ra
i ra QJ a>
. j j- __i -I-
u j- *- at in ai M-
J C3 O CL 4-» CL OI
JOE c o x: c
31 =J QJ 4-> -r-
3 =-g&s-s fce
a *- nj Qt rara QJ*O
«0 X» QJ 4-» >
- L. * t. O QJ
> O W -M H- CJ X:
= , u) .- in 4-»
I Q) Q) 3 -O 4J Q>
QJ
in QJ
s«
QjC-c Q. O
I Q£ n
iSg--
S^'S^
S O +J ra
5 t. ro t, E
i (§ Q.J-i ° QJ
ac in *J
ra 01 -i
O QJ (J Ul
** W x: u
t, E QJ O
in
_ . i_ u ist o :=
at o -f- *r- c
to ra 4-> LU
°|23C
S^ O. O ^s *-
§s u 25 °
: ... M- c
lo'S-.i!'
ii§
g"o
a. a
v o
_ t* 0) > t/1
QJ (U > -I-
« « o ^ «
. . - c j
i O c -i
n 3E "~
. ^* x: i
'o4""
> a>
oj
a
o
a
I
C t.
i M
o . tP 4J
° y
-
C B W 0
tJ tP O iP
0) O W C
n vi a< a)
a0" 'a, I
i
m u U O
j= ra c M
3 CU -U
P (PC
C CO < O
o - -rt 0
5 rH *J -H
-O -H CJ 4J
O CU 3
(fl C 4-) <-4
H 3 O ^H
Q
2 Q
2UI
-------
OCPC began to examine the alternatives avail-
able to correct the identified needs. Up to
seven alternatives (which included everything
from advanced waste treatment to onsite
disposal) were examined in detail for each of
the communities studied. <
Although this case study does not examine
the evaluation strategy for each community, '
the impact of the work that OCPC had done !
on defining onsite disposal problems was
clearly demonstrated. Onsite disposal was
technically feasible in nearly all parts of the
planning area and was a cost-effective solution:
in most situations. Through these studies, 201'
plans are being re-evaluated and the location
of a proposed regional wastewater treatment
plant is being reconsidered in light of a better ;
understanding of subsurface disposal systems.
The OCPC has also communicated the find-
ings of their survey to their member commu-
nities through workshops, seminars, and other
public forums. A direct mail approach was
utilized during the fall of 1977 when they sent
homeowners a brochure on septic tank main-
tenance (Figure 5). Use of this brochure im-
proved public relations with the member
communities. The OCPC and member com-
munities feel that a reasonable plan for re-
gional water quality and for protection of indi-
vidual homeowners has resulted from this
effort. :
The result of the onsite wastewater disposal
survey has been to modify the proposed 201
facilities plans, to change homeowners percep-
tion of septic tanks, and to present cost-
effective disposal options to communities in
the OCPC area. The methods developed for
the onsite disposal survey and the evaluation
procedures used to derive alternatives for
wastewater disposal shall lead to improved
water quality for the areawide planning com-
munity.
11
*U.S. GOVERNMENT PRINTING OFFICE: 1978 757-140/6668
-------
------- |