I -
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A Series About Onsite
Wastewater Treatment
Alternatives
January 2005
Authors
Lorraine Joubert, George Loomis,
David Dow, Art Gold, Diana Brennan,
and Justin Jobin
University of Rhode Island
Cooperative Extension
Water Quality Program
Kingston, RI 02881
Peter Flinker
Dodson Associates, Ltd.
Ashfield, MA 01330
Editing By
Lisa DeProspo Philo
University of Rhode Island
Cooperative Extension
Published by
University of Rhode Island
Cooperative Extension
Natural Resources Science Department
Coastal Institute
Kingston, RI 02881
This publication is available in pdf format at
www.uri.edu/ce/wg / Printed copies may be
purchased through the Cooperative Exten-
sion Education Center at 401-874-2900.
ii i i i iii ii i ii
= ‘ Ill
UNIVERSITY UI
Rhode Island
Alternative Wastewater Treatment for Individual Lots
P
Table of Contents: Alternative Wastewater Treatment for Individual Lots
Introduction I
Chapter 1: The Case Studies 2
A Stony-Soil, Coastal Site 2
A Small Summer Lot 4
A Sustainable Landscape for Lawn-Lovers 6
A Site With Unique Wetlands 8
A Small, Sandy-Soil Site 10
A Sloping, Landscaped Site 12
A Tiny Waterfront Lot 14
Chapter 2: Hints for Aesthetic Enhancement of
Systems 16
P4terqatlves to Above-Ground Treatment 16
. Paying Attention to Details 16
Placing System Components With Care 17
Chapter 3: A Checklist 18
References 18
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Introduction
The factors involved in selecting a
wastewater treatment system are
numerous. As a property owner,
you may be faced with space
limitations or other site constraints
on the property. There may be
specific treatment requirements,
and costs associated with the
installation, maintenance and
operation of the system must
be considered. The availability
of support from companies
supplying treatment components
may be another factor. Choosing
to install an alternative system
often permits fuller enjoyment
of the property while achieving
higher levels of treatment than
conventional systems offer.
This manual is the second in a
series about alternative wastewater
treatment systems. While the
manual Choosing a Wastewater Treatment
System provides detailed information about
conventional systems, modifications to those
systems, and alternative systems, the chapters
that follow highlight real-world cases where
alternative systems have overcome unique
site constraints to meet specific treatment
objectives. These case studies explore a variety
of factors involved in selecting a system and reveal
how alternative systems can permit a greater
use of property area while maintaining distinctive
architectural or natural features. In each case, the
alternative system was constructed as a repair
to a failing or substandard conventional system.
Advanced treatment technology was selected to
protect sensitive coastal waters and groundwater
supplies, because a conventional system repair
was simply not feasible or would have required
extensive and costly site disturbance.
Important Notes About This Manual
The case studies discussed within this manual
focus upon the individual site constraints that
influence the choice of wastewater treatment
system. However, choosing the most appro-
priate treatment system is equally influenced
by watershed-level factors such as watershed
susceptibility to nitrogen or bacterial inputs.
This is especially important for lots located in
coastal areas, near freshwater, or within an
aquifer. System designers should be aware
of local regulations and also may be able to
recommend treatment systems that are most
appropriate for the local area.
In addition to the benefits that accrue to prop-
erty owners, the surrounding neighborhood’s
character may be enhanced when alternative
systems are used on individual lots. Alternative
systems can support compact development to
minimize sprawl and promote pedestrian-
friendly, distinctive neighborhoods. They also
enable communities to retain their architectural
or natural features, while protecting public and
environmental health.
Alternative Wastewater Treatment for Individual Lots I
In this historical seaside village, the characterand growth of Main Street-
as well as local shelifishing - were preseived using alternative wastewater
technology. Small town and village centers in rural areas often rely on
conventional wastewater treatment technology that doesn’t meet cur-
rent state standards and can’t be made to do so in the available spaces.
Advanced wastewater technology can support the reuse of town center
buildings, while maintaining the simplicity of individual systems.
— -
Conventional wastewater treatment system siting and design standards tend to reinforce the need for large lots
and extensive property disturbance. The house on the left uses a raised “mounded” or “fill” drain field, contained
by sidewalls. This uses almost all of the available lot. An alternative treatment system would have enabled the
property owner to avoid such extensive disturbance to the yard.
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Chapter 1: The Case Studies
Case #1: A Stony-Soil, Coastal Site
This one-third acre site located in a nitrogen- and
pathogen-sensitive coastal watershed is almost
completely surrounded by a wetland. The site
has wet, glacial till soils with numerous stones
and large boulders. As a result of the high water
table, groundwater is at the surface of the lot for
several months during the wet season. The home
and the surrounding neighborhood are serviced
by a town water supply.
The Constraints
A nitrogen- and bacteria-sensitive coastal
site
• Stones and large boulders
• Ahighwatertable
The Existing System
A 500-gallon cesspool
The Solution
• A recirculating media filter
• A bottomless sand filter drainfield
Replacing the cesspool with a conventional
septic system would have drastically altered
the site. Most of the yard area would have been
required for the system; boulders would have
been excavated and trees removed. Four feet
of gravel would have been brought in to raise
the drainfield above the water table, and a pump
would have been installed to move septic tank
effluent to the raised drainfield. In the absence
of a level 25-foot area surrounding the drainfield,
retaining walls would have been constructed to
contain the fill material. Because of the degree
of excavation and amount of fill material required,
the cost of this conventional system would have
far exceeded the cost of the alternative system.
In addition, the landscape alterations required
by the conventional system would have altered
stormwater movement and aggravated the already
wet site conditions.
2 Alternative Wastewater Treatment for Individual Lots
The existing system for this site consisted of an
approximately 500-gallon cesspool, which was
pumped four times a year. An auxiliary drainfield
line was also present. A shallow pool of water
covered the cesspool during the wet season which
would flow through a neighboring lot and then into
the adjacent coastal wetland.
Surfacing cesspool before repair -- near house.
The typical conventional septic system fix would completely alter the lot, and most of the yard would be
required.
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A recirculating media filter was selected as the
treatment unit that could effectively overcome the
constraints presented by the site. A bottomless
sand filter was added to provide additional
treatment. With this system, the wastewater
flows from the house into a septic tank with two
pumps controlled by separate timers. One pump
recirculates the effluent to a media filter, and the
other disperses this blended effluent to the raised
bottomless sand filter, located on the highest point
in the yard.
The media filter was selected for its small
footprint and nitrogen-reducing performance.
In fact, this alternative system provides a minimum
of 50% nitrogen removal to help protect nearby
coastal waters. The bottomless sand filter was
the only drainfield option available for this high
water table site. It provides bacterial reduction
and avoids large amounts of fill material. The
alternative system significantly minimizes site
disturbance and surface topography changes
that would have altered stormwater movement.
It blends into the landscape, among boulders
and trees, while providing a much higher level of
treatment than a conventional system could offer.
Thus, the use of an alternative treatment system
on this real-world site maintained distinctive natural
and architectural features of the property while
protecting public and environmental health.
C
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tator Unit RecIrculating
- - Textll Pump Chamber v t-
E.iefl Retur
Septic
Tank
. Pipes Drain
Field
Lot size is 80 feet by 175 feet
,
Road
Alternative Wastewater Treatment for Individual Lots
H, e Fr fl HOUSt;
Flow from the house enters septic tank (A), recirculates
to the media filter (B) and is then pumped to the bot-
tomless sand filter for final treatment and dispersal (C).
The alternative system fits into the landscape, amid
boulders and trees while providing a much higher level
of treatment than a conventional system.
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Case #2: A Small Summer Lot
Homes in this low-lying, sandy soil coastal plain
are primarily seasonally-occupied, and they often
experience intense summer use. The home on this
site, like most of the older homes in this working
class summer resort neighborhood, dates back
to the period between the 1 950s and 1 970s. The
house is situated on a small, 50-foot by 100-foot
lot. In fact, lots of five thousand square feet are
common for the area. The site is approximately
300 feet from a coastal pond. Well and septic
system setbacks are rarely met, and wells on both
the case study site and a neighboring lot were
approximately 50 feet from the failed cesspool.
The goal for this site was to maintain the
architectural and natural elements of the
neighborhood by avoiding large, obtrusive,
raised fill systems. An additional goal was to
remove nitrogen and bacteria in order to protect
groundwater supplies as well as the nearby
coastal pond.
A conventional solution for the small size of
this lot would have been to install deep galleys.
However, the water table on this site is too
shallow for such a system, and galleys do not
achieve the necessary level of nitrogen and
bacteria reduction.
To save limited space, a modular recirculating
media filter was placed under a cantilevered
room of the house, leaving the remaining 15-foot
by 50-foot usable backyard space for the septic
tank and shallow, narrow drainfield. Wastewater
from the home enters the septic tank, where it then
recirculates to the media filter that fits in the crawl
space under the cantilevered room of the house.
The wastewater is dosed to the shallow, narrow
drainfield where additional treatment occurs.
The Constraints
• Asmalliot
• Low-lying, sandy soil in a nitrogen- and
bacteria-sensitive coastal area
• Intense summer use
• Nearby private wells
The Existing System
Afailed cesspool
The Solution
• A modular recirculating media filter
• A shallow, narrow drainfield
4 Alternative Wastewater Treatment for Individual Lots
The house sits on a narrow 5000 square foot lot, with
little room for a conventional septic system.
An aerial view of the flat coastal plain, where many dense summer colonies were established in the days
before septic systems were commonplace.
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Two houses are shown in the left of the
photo below. The drain field can be seen
in the center, with the coastal pond in the
background approximately 300 feet away.
A separate shallow, narrow drain field for
the neighboring lot can be seen in the
background of the photo below. The
recirculating media filter is shown, left and
below, located in the crawl space under the
cantilevered bay window.
Road
Septic Treatment
Tank Unit
. Pipes Drain
Field
Al
Lot size is 50 feet by 100 feet
‘Recirculating Split-
The system layout above shows the septic tank (A),
media filter (B) and drain field (C). Wastewater from
the home enters the septic tank, where it then recir-
culates to the media filter in the crawl space, then is
dosed to the shallow narrow drain field where addi-
tional treatment occurs.
I; ,
WeII
a
CD
C
Drainfield Pump
Alternative Wastewater Treatment for Individual Lots 5
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Case #3: A Sustainable Landscape
for Lawn-Lovers
This one-third-acre lot is located in a flat coastal
plain with sandy soils and an eight-foot-deep water
table. Homes in this area are typically 1950s vin-
tage, with about half occupied year-round. The
existing system consisted of a cesspool that had
hydraulically failed and was surfacing. The home-
owner’s primary objective was to maintain a
vigorously growing turf on the landscaped site.
Another important objective for this site was
to remove nitrogen, so although a conventional
system easily could have been accommodated on
the lot, it would not have provided the desired treat-
ment level. A standard trench drainfield or shallow
leaching chambers may also have been used as
a conventional option, although the homeowner
would have missed the opportunity to reuse the
moisture and nutrients for his lawn that are circu-
lated by the alternative system that was chosen.
The system selected was a septic tank followed by
a pump tank that doses a drip-irrigated field. The
drip irrigation tubing was installed six inches below
ground surface to maximize nutrient and moisture
use by the turf. Although the yard was large
enough to accommodate almost any technology,
the drip irrigation fit well on the site because there
was sufficient space to accommodate the required
amount of drip tubing. Recycling wastewater in
the irrigation system has the additional benefit
of conserving well water that the homeowner
would have used to water the lawn.
In this system, wastewater from the home enters
the septic tank where solids settle. Effluent flows
to the dosing tank and is pumped through disc fil-
ters that remove fine organic particles that might
clog the drip irrigation lines. A sand-lined, shallow
narrow drainfield was also installed as a backup
to the drip field.
• A nitrogen-sensitive coastal site
• A landscaped lot with well established and
valued lawn
The Existing System
Afailed cesspool
The Solution
• A septic tank and a disc filter
• A dosed, drip-irrigated field
• Reuse of treated wastewater to maintain
lawn
6 Alternative Wastewater Treatment for Individual Lots
The Constraints
w’ •• k
A Fertilizer Caution
The application of fertilizers to promote
lawn growth can offset the nutrient reduc-
tion achieved by an alternative waste-
water treatment system. To promote a
healthy lawn using sustainable practices,
experts suggest that you use no more
than one pound of slow-release fertilizer
per one thousand square feet and that
you return clippings to the lawn.
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Septic Treatment
L_J Tank Unit
Drain Dosing Tank
Field and Pipes
;ti
o
—
Driveway
Lot size is approximately one-third of
The layout of the drip irrigation system is shown above.
Wastewater from the home enters the septic tank (A)
where solids settle. Effluent flows to the dosing tank
(B) and is pumped through disc filters that remove fine
organic particles that might clog the drip irrigation lines
(C). A sand-lined, shallow, narrow drain field (D) was
also installed as a backup to the drip field but has not
been used.
The drip irrigation lines drawn in green on the photo,
right, were installed with a vibratory plough thai caused
little disturbance to the lawn. In addition, the contractor
was able to minimize further damage by removing and
then replacing topsoil in the areas of installation.
0
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Alternative Wastewater Treatment for Individual Lots
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Case #4: A Site With Unique Wetlands
This sandy soil lot is half of an acre and is located
close to a small, yet environmentally-important,
vernal pool. Vernal pools are a type of wetland
that occur primarily during the wet spring season,
and they provide a unique habitat for threatened
species of amphibians. These vernal pools are
located throughout several sites in this portion
of the community. The topography of the site is
slightly rolling, and it has a high water table at
about three feet. This home, along with others
in the neighborhood, relies on well water. The
existing system on the site was a failed, bed-type
drainfield.
The primary treatment objective in this
process of selecting a wastewater system was
to maximize bacteria and phosphorus removal,
enhancing the protection of the drinking water
well and the unique wetland feature.
A single-pass sand filter was selected for this
site because it is a reliable pathogen removal
technology, used for more than 100 years to
treat water and wastewater. The single-pass
sand filter is more effective in removing bacteria
than a recirculating filter, which excels in nitrogen
reduction. In addition, single-pass sand filters are
larger than recirculating media filters, and space
was available on this site. The shallow, narrow
drainfield provides additional nitrogen and bacteria
removal to protect groundwater and phosphorus
treatment to protect the vernal pool from nutrient
enrichment.
This system required little site alteration,
which prevented disruption of the wetland
buffer and allowed existing landscaping to
remain. A conventional septic system would
have required clearing, regrading, and filling to
adjust for slopes and to raise the drainfield at
least two feet to achieve the required separation
to groundwater.
In this alternative system, wastewater from the
home enters the septic tank. This effluent is then
dosed to the single-pass sand filter. Final treated
effluent is then dispersed to a shallow, narrow
drainfield.
The Constraints
• A nearby, environmentally-important
vernal pool
• A bacteria- and phosphorus-sensitive
area
• Some existing landscaped area
The Existing System
• A failed bed-type drainfield
The Solution
• A single-pass sand filter
• A shallow, narrow drainfield
The layout for a single-pass sand filter system on the
lot with nearby well and wetlands is shown above.
Wastewater from the home enters the septic tank (A),
and this effluent is then dosed to the single-pass sand
filter (B). Final treated effluent is then dispersed to a
shallow narrow drain field (C).
8 Alternative Wastewater Treatment for Individual Lots
[ Septic Treatmen l
L......JTank Unit
Pipes rT Drain
Field
Lot size is 210.5 feet by 220 feet Driveway
.
-
Vernal pools, wnicn oy aerinition exist only in the
spring, support a unique variety of plants and animals
that have adapted to these special conditions, These
include a number of endangered amphibians that are
easily displaced by any disturbance to nearby areas.
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Two-Compa th flt 7 f
Sepf}cTank .
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Sand ther j . .
DOsingPump 4,; I: —
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Filter with Pump
Disçharge
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This photo provides a more detailed view of the lot. Wastewater flows by gravity from the home to a two-compartment septic tank. (The shadow of the house is visible
on the left of the photo.) A pump located in the second half of the tank dispenses effluent to the sand filter, which is located just below the ground surface. The treated
effluent is then pressure-dosed to the shallow drain field. These units were installed without disturbing the existing landscaping and wooded wetland edges.
Alternative Wastewater Treatment for Individual Lots 9
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Case #5: A Small, Sandy-Soil Site
With a total area of 6,000 square feet, this
site has extremely limited usable space to fit a
house, septic system, well, and parking area. In
addition, the site is located directly on the shore
of a nitrogen-sensitive coastal pond that has been
closed to shellfishing due to high bacteria levels,
and nutrient enrichment at the shoreline of the
property has caused an overabundant growth
of nuisance algae. A dug well drawing from a
shallow freshwater lens provides water to the
1950s vintage home. The existing failed system
consisted of a series of two 55-gallon steel drums,
an approximately 300-gallon steel septic tank, and
a 600-gallon cesspool.
The primary objective for this site was to
choose a wastewater treatment system that
would retain existing landscaping and natural
features within this coastal neighborhood,
including views of the property from the water,
while protecting the coastal pond and nearby
well from nitrogen and bacteria. An equally
important consideration was the small size
of the lot.
Until a few years ago, the conventional option
for such small lots with deep, sandy soils would
have been a septic tank followed by deep concrete
leaching chambers. This type of system has
an extremely small footprint but provides little
treatment. Instead, a septic tank, recirculating
media filter, and shallow, narrow drainfield were
chosen as an alternative system for this site.
Wastewater from the house enters the septic tank
where effluent is then pumped to the recirculating
media filter. The treated effluent is then dosed to a
two-zone shallow, narrow drainfield, half of which
is located under the clothes line in between the
home and the fence at the lot line.
The Constraints
• Sandy soils
• An adjacent, nitrogen-sensitive
coastal pond
• Existing high bacteria levels
• Extremely limited usable space
The Existing System
• Two 55-gallon steel drums
• 300-gallon steel septic tank
• 600-gallon cesspool
The Solution
• A recirculating media filter
• A shallow, narrow drainfield
The house occupies a narrow lot with a
sandy beach directly on a coastal pond.
A small space between the house and the
fenced property line on the right, which
now accommodates a clothesline, is the
only available space for a drain field.
Overabundant growth of nuisance
algae caused by nutrient enrichment at
the shoreline of this property is shown
at right.
Alternative Wastewater Treatment for Individual Lots
I.,,
-------
Pond
Septic Treatment
Tank Unit
• Pipes • r J ° Well
n N
The layout for a recirculating media filter system for a
lot with limited space is shown above. Wastewater from
the house enters the septic tank (A) where effluent is
then pumped to the recirculating media filter (B). The
treated effluent is dosed to a two-zone shallow narrow
drain field (Cl and C2).
Lot size is approximately 55 feet by 110 feet
Two views of the recirculating media
filter system are shown at right. Half
of the drain field is located under the
clothes line, in between the home and
the fence at the lot line.
Alternative Wastewater Treatment for Individual Lots 11
Gravel
Driveway
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Case #6: A Sloping, Landscaped Site
This one-half-acre lot has rocky, glacial-till soils,
well-established landscaping, and many obstacles
that render the site with little usable space in which
to fit a conventional septic system repair. Although
the site has a fairly deep water table and municipal
water service, the adjacent coastal pond, located
approximately one block from the site, is sensitive
to nitrogen and bacterial inputs. This site’s slope
directs stormwater runoff directly to the coastal
pond.
Due to the slope of this lot, a conventional
system would have required extensive clearing
with large amounts of machine time and gravel
fill to enable level areas for drainfield lines.
Equally importantly, a conventional system
would have provided little nitrogen removal.
The alternative system selected had to fit into an
area under an existing raised deck to save space
and to preserve the existing landscaping. A series
of alternative treatment units were chosen as the
most effective method of wastewater treatment.
These include a septic tank with a pump that
doses a single-pass media filter, an ultraviolet
light disinfection unit, and a shallow, narrow
drainfield.
Wastewater from the house enters the septic tank
where effluent is dosed to the single-pass media
filters located under the deck. Treated wastewater
then flows through the ultraviolet light disinfection
unit and is dosed to the shallow, narrow drainfield
adjacent to an existing fern garden.
The media filters come in pre-packaged modular
units that provide flexibility in siting, simplify
installation, and enable limited site disturbance
to the lot during construction. The ultraviolet
light disinfection unit provides an additional level
of bacterial removal to help reduce the pollution
risk from this system.
Using an alternative system on this sloping,
landscaped site eliminated extensive filling
and regrading of the lot, maintained the natural
elements of the landscape, and achieved high
levels of nitrogen and bacterial removal.
The Constraints
• Well-established landscaping
• Sloping lot
• Rocky soils
• An adjacent, nitrogen- and bacteria-sensi-
tive coastal pond
The Existing System
• A conventional septic tank
• A bed-type drainfield with some hydraulic
failure
The Solution
• A septic tank with a pump
• A single-pass, modular, media filter
• An ultraviolet light disinfection unit
• A shallow, narrow drainfield
Alternative Wastewater Treatment for Individual Lots
The sloping lot increases the potential impact of a
conventional system.
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The system is designed fora sloping site where bacterial
removal is important. The layout is shown at left.
Wastewater from the house enters the septic tank (A)
where effluent is dosed to the single-pass media filters
(B) located under the deck. Treated wastewater flows
through an ultra violet light disinfect ion unit (C) and then
is dosed to the shallow narrow drain field (D).
Lot size is approximately half an acre
Q)
a.
The modular media filters were located under the raised
deck (photo, bottom left) to save space and fit into the
existing landscape.
Alternative Wastewater Treatment for Individual Lots .
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Case #7: A Tiny Waterfront Lot
Homes on postage stamp sized lots had little
impact on water quality when first built decades
ago. But now, with years of infill development
and the shift to year-round use, the summer
cottage neighborhood has hastened the loss
of recreational and commercial use of a water
The next example is one such lot, located on a
peninsula, surrounded by a poorly flushed coastal
pond that is permanently closed to shellfishing
due to bacterial levels. The pond is also showing
signs of nitrogen enrichment. This roughly 4,000
square-foot lot has very limited space, and a
conventional system would neither fit on the site
nor would it protect the pond. Even the most
advanced treatment systems would not fit in the
available space on this lot.
In order to meet the space and treatment
demands of this site, a system incorporating
fixed activated sludge technology was
installed. This is a space saver system
because the treatment unit itself actually rests
within the septic tank, eliminating the need
for separate space to fit the treatment unit. A
recirculating media filter also would have been
appropriate for this site, but it would have used
slightly more space. This technology, followed
by an ultraviolet light disinfection unit, minimizes
inputs of nitrogen and bacteria from this particular
lot, protects the receiving water body, and has
as small a footprint as possible. This example
illustrates the use of alternative technology to
maintain the quaint charm of a neighborhood,
while allowing the landowner to renovate and
revitalize his home.
The Constraints
• Extremely limited usable space
• A nitrogen- and bacteria-sensitive coastal
area
The Existing System
• 325-gallon steel septic tank
• A bed-type drainfield in contact with the
water table during the wet season
The Solution
• Fixed activated sludge technology
• An ultraviolet light disinfection unit
• A shallow, narrow drainfield
Alternative Wastewater Treatment for Individual Lots
resource.
A small footprint system was required for this lot with
very limited space. The existing house was originally
a seasonal home with a building footprint less than 600
sq. ft (above). With remodeling, the footprint was slightly
enlarged (below). The number of bedrooms remained
the same, keeping potential occupancy at the same
level and preventing an increase in nutrient loading.
-------
Pond
-
Lot size is 50 feet by 100 feet
Treatment
Unit
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fin
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AB-,
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Septic
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Pipes
J!Drain
b 1 Field
As shown in the diagram (left), wastewater from the
house enters the septic tank (A) and flows through
the fixed activated sludge system (B). Treated
wastewater flows through an ultraviolet light dis-
infection unit (C) and then is dosed to the shallow
narrow drain field (D). The fixed activated sludge
unit sits inside the septic tank, producing a small
system footprint (right).
N
.
Bldwer
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Co
a)
>
a
Alternative Wastewater Treatment for Individual Lots
i ump tsasin with
UV DisinfecUon Unit
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Chapter 2: Hints for Aesthetic Enhancement of Alternative Systems
This chapter attempts to help the reader
understand the fundamental principles of system
placement, setback, landscaping, and aesthetic
issues that often determine how the property
owner and neighbors feel about the system.
Although it is the designer’s responsibility to make
sure the system meets all of these parameters, it is
certainly advantageous for a homeowner to have
basic knowledge about how a system should look,
how it can fit the home landscape, or how it can
blend into a subdivision without looking obtrusive.
The following case studies illustrate how attention
to the aesthetic impacts of a system can produce
a finished product that blends more naturally into
the surrounding environment.
Alternatives to Above-Ground Treatment
using a conventional (gravity-fed) drainfield. The
media filter serves the house on the left, where
only a corner is barely visible; the fence behind
the tank and filter mark the adjoining property
boundary with the house in the background.
The recirculating media filter, which is raised well
above the original ground surface and landscaped
with native shrubs, uses up more space than
actually needed. It effectively limits the owner’s
use of that portion of their property and creates
an aesthetic concern.
Incorporating the following simple changes
would have allowed the homeowner greater
use of the yard space.
Paying Attention to the Details
It is important to consider how the system will blend
with surrounding properties. In the photo (below)
the site in the foreground shows a treatment
system with a shallow, narrow drainfield. This is
apparent by the strips of greener grass. When
the neighbor to the rear decided to replace his
system with a similar advanced treatment system,
the installer took care to line up the drainfields for a
neater look. This is a minor point, but a nice touch
from an installer who put a little extra thought and
effort into system aesthetics.
• Tank risers should be trimmed flush with
the ground surface so a lawn mower could
move directly over them.
• A second pump could have been used to
dose a shallow, narrow drainfield rather
than using a conventional gravity-fed
drainfield.
This would have required one more pump, but the
advantages would be:
1) the media filter would be flush with the ground
surface, blending into the existing landscape
more easily;
2) a shallow narrow drainfield could have been
installed easily with minimal disturbance of
the yard; and
3) the shallow narrow drainfield would also
provide additional wastewater treatment.
Recent studies show additional nitrogen and
total phosphorus removal rates in shallow
drainfields range, respectively, from 33 to 55
percent annually and from 55 to 100 percent
annually (Holden, 2004).
16 Alternative Wastewater Treatment for Individual Lots
On this small flat coastal plain lot (photo, below)
located in the watershed of a nitrogen-sensitive
coastal pond, a recirculating media filter was
installed to achieve a state-imposed discharge
standard of at least 50 percent total nitrogen
reduction. Although this technology was a good
choice for this area from a treatment and space
allocation perspective, the designer insisted upon
.A : :
I
A single family home with a raised, recirculating media
filter and conventional gravity flow drainfleld.
. ... .
A conscientious installer, paying careful attention to
detail, lined up the drain field lines on these two separate
lots to produce a more orderly and aesthetically pleasing
look.
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Placing System Components With Care
Two adjoining lots in a coastal pond neighborhood upgraded failed septic
systems using advanced treatment systems. Recirculating media filters,
followed by bottomless sand filter drainfields, were used to achieve several
objectives. These systems needed to achieve nitrogen and bacterial
removal, needed to fit on a small lot, and needed to accommodate high water
table conditions. The orange line shown in the photo marks the property
boundary; the treatment unit is outlined in yellow, and the bottomless sand
filter is on the right of the pine tree (below, left).
Unfortunately for the homeowner, the system components became the
focal point of the landscape when placed in a highly visible, open area. An
alternative placement scenario could have been to site the treatment unit
along the property boundary, as shown in the foreground. The bottomless
sand filter could have been designed as a long narrow rectangle and sited
along the hedge line to the right of the current location, as shown with the
dashed blue line. In addition to opening up more usable space, a long
rectangular bottomless sand filter configuration actually functions more
effectively, and it is easier to install and maintain.
In the adjoining lot shown below, right, similar redesign would have allowed
greater use of the property and avoided the need for costly landscaping
to camouflage treatment units. The property boundary, as shown by the
orange line, extends beyond the left side of the photo, with space at the
corner of the property, left of the telephone pole, for the treatment unit.
The bottomless sand filter, located in front of the shed at the rear of the
property, currently blocks the shed door, preventing it from opening fully.
The bottomless sand filter could have been designed in a long rectangular
shape and sited along the hedge following the property boundary on the
left.
Two properties where redesign of system components would allow greater use and aesthetic enjoyment.
Alternative Wastewater Treatment for Individual Lots
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Chapter 3: A Checklist
The case studies in the previous chapters
offer basic tips to help systems blend into the
home landscape. When systems are sited
with care and with attention to detail, system
owners and neighbors can appreciate the
flexibility of the technology and focus upon
the aesthetic quality of the property rather
than the treatment system. The following
is offered as a checklist for fitting alternative
systems into the landscape:
Site Aesthetics
El Work with the existing topography,
buildings, and vegetation to blend
components into the landscape.
o Will any treatment units be above
ground? Special care is needed to fit
these into the landscape unobtrusively.
El Place components along existing edges
such as vegetation borders, shrub rows,
driveways, or stone walls.
El Whenever possible, avoid putting units
in the middle of lawns or other open
spaces.
o Use natural materials such as wooden
timbers and rocks to encase the sides of
treatment units.
o Small modular treatment units can be
tucked into crawl spaces and under
decks, provided access is maintained.
Property Enjoyment
D Where possible, locate treatment units
and drainfields away from high-use
areas.
El Electrical panel boxes can be noisy, as
switches controlling pumps go on and
off. These should be located on the
outside of utility walls or high-use areas
such as garages, entryways, or kitchens
where refrigerators, air conditioners,
or other utilities already create some
noise.
El When locating shallow, narrow
drainfields in playing fields, cover
inspection ports with turf for safety but
tag them beforehand with metal markers
to easily identify with a metal detector
when maintenance is due.
o Activated charcoal pads can be inserted
at the top of dra infield inspection ports if
odors are a problem.
System Functioning
El Keep in mind the convenience and
safety of maintenance providers. Locate
panel box for easy access.
o Use grade changes to avoid an additional
pump. For example, when using a
recirculating system, locate the bottom
of the treatment unit up gradient of the
inlet of the recirculating tank, thereby
allowing gravity flow back to the tank.
References
Joubert, L., P. Flinker, G. Loomis, D. Dow,
A. Gold, D. Brennan, and J. Jobin. 2004.
Creative Community Design and Wastewa-
ter Management. Project No. WU-HT-00-30.
Prepared for the National Decentralized
Water Resources Capacity Development
Project, Washington University, St. Louis, MO,
by University of Rhode Island Cooperative
Extension, Kingston, RI. Available online at
http://www.ndwrcdp.org/publications.cfm and
through the National Small Flows Clearing-
house, Morgantown,WV.
H & R Environmental Consultants. 1998.
Assessing Waste water Options for Small
Communities, Trainer’s Manual for Local
Decision Makers. The National Environmental
Training Center for Small Communities. Mor-
gantown, WV.
Holden, S.A. 2004. Nutrient Leaching From
Shallow-Narrow Drainfields. Department of
Natural Resources Science, Master of Sci-
ence Thesis. University of Rhode Island,
Kingston, RI.
University of Minnesota Extension Service.
1998. Alternative Wastewater Treatment Sys-
tems. Residential Cluster Development Fact
Sheet Series. University of Minnesota.
Photo credits — unless otherwise noted all
system diagrams are from the University of
Rhode Island Cooperative Extension Water
Quality Program.
Further information about alternative waste-
water treatment can be found at:
http://www.uri.edu/ce/wp
http://www.onsiteconsortium org
http://wwwnesc.wvu.edu/nsfc/nsfc _ index.htm
18 Alternative Wastewater Treatment for Individual Lots
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This series is condensed from “Creative Community Design and Wastewater Management”, prepared by URI Coop-
erative Extension for the National Decentralized Water Resources Capacity Development Project (NDWRCDP).
The full report is available at the NDWRCDP website at http://www.ndwrcdp.org/publications.cfm
For additional information, please consult the other manuals in this series:
The Creative Community Design and Wastewater Management report was supported by the National Decentralized Water Resources Capacity Develop-
ment Project (NDWRCDP) with funding provided by the U.S. Environmental Protection Agency through a Cooperative Agreement (EPA No. CR82788 1-
01-0) with Washington University in St. Louis. This report has been reviewed by a panel of experts selected by the NDWRCDP. The contents of this
report do not necessarily reflect the views and policies of the NDWRCDP, Washington University, or the U.S. Environmental Protection Agency, nor does
the mention of trade names or commercial products constitute endorsement or recommendation for use.
This material is based upon work supported in part by the Cooperative State Research, Education, and Extension Service, U.S. Department of Agriculture,
under Agreement No. 00-51130-9775. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s)
and do not necessarily reflect the view of the U.S. Department of Agriculture.
Development of these condensed reports was made possible by the Block Island and Green Hill Pond Watershed National Decentralized Wastewater
Demonstration Project, funded by the US Environmental Protection Agency. This “Safewater” project is a community effort by the Towns of South Kings-
town, Charlestown, New Shoreham and the University of Rhode Island to protect, recycle and sustain local water resources. The Rhode Island Depart-
ment of Environmental Management Nonpoint Pollution Program and the Town of South Kingstown provided funds for printing.
Cooperative Extension in Rhode Island provides
equal opportunities in programs and employment
without regard to reace, color, national origin, sex
or preference, creed or disability. University of
Rhode Island, U.S. Department of Agriculture, and
local governments cooperating. This is contribu-
tion #4069 of the College of the Environment and
Life Sciences, University of Rhode Island.
Ntion
Decen mllz.d
water
R
C.—
Development Project
( )
CSREES Rhode Island
New England l)epartment of
Pogiond Wo$o jaIty Puogiom Fnvlroii mental
\laiiagnieiil
SAF WA ER
Alternative Wastewater Treatment for Individual Lots 19
N.+.o ’ ,aI D.o.,’,.. zo ,i W,,s., R.s. ..
k Copo +y . -$ Po. 1 .d
Creotive Community De5Igr, and
Wartewat.r Monog.m.nt
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Acknowledgements
The authors would like to recognize the many
individuals who contributed example projects
using decentralized systems to support creative
development designs, those who provided
supporting information on wastewater treatment
technologies or land use issues, and others who
generously assisted in reviewing this document.
These contributors include: Ken Anderson;
Randall Arendt; Joseph Bachand; Todd Chaplin;
Marilyn Cohen; Keith Dobie; \NiIliam Faulkner;
Robert Gilstein; Ray Goff; Steven Goslee;
Bruce Hagerman; Mary Ellen Horan; Paul
Jestings; Joefta Kirk; Deborah Knauss; Tony
Lachowicz; James Lamphere; Susan Licardi;
Craig Lindell; Geoffrey Marchant; Scott Millar;
Brian Moore; Scott Moorehead; Vincent Murray;
Ray Nickerson; Douglas Ouellette; Jon Schock;
M.. Shepard Spear; Gus Walker.
Special thanks to the West Virginia University
National Small Flows Clearinghouse for use
of wastewater treatment system illustrations;
Gary Blazejewski and Kaytee Manchester, URI
Natural Resources Science, for assistance in
graphics and final report preparation.
Several of the example onsite and cluster
decentralized wastewater treatment systems
shown in this manual are demonstration systems
constructed by the University of Rhode Island
Cooperative Extension Onsite Wastewater
Training Center as repairs for research, training
and outreach. Construction and monitoring of
these systems was funded by the RI AquaFund,
the National Onsite Demonstration Project,
Phase II; the EPA Block Island and Green
Hill Pond National Community Decentralized
Wastewater Treatment Demonstration Project;
the RI DEM Nonpoint Pollution Program (section
319) and the Town of Glocester, RI. These are
all functioning systems in regular use located
on private residential or commercial property.
We recognize the extra care and attention
taken to design and construct these innovative
wastewater treatment systems by the members of
the RI Independent Contractors and Associates.
We also thank the RI Coastal Resource
Management Council and the RI Department of
Environmental Management for their cooperation
in demonstration system permitting and for their
support for use of decentralized wastewater
treatment systems to protect water resources
and promote sustainable development.
Appreciation is expressed to the NDWRCDP
for their support of this work and review by the
project steering committee and staff:
Principal Investigator
Jay R. Turner, D.Sc., Washington University
Project Coordinator
Andrea L. Arenovski, Ph.D.
Project Steering Committee:
Coalition for Alternative Wastewater Treatment
Valerie I. Nelson, Ph.D.
Consortium of Institutes for Decentralized
Wastewater Treatment
Ted L. Loudon, Ph.D., P.E.
Mark Gross, Ph.D., P.E.
Electric Power Research Institute
Raymond A. Ehrhard, RE.
Tom E. Yeager, P.E.
National Onsite Wastewater Recycling
Association
Jean Caudill, R.S.
National Rural Electric Cooperative Association
Steven P. Lindenberg
Scott Drake, P.E.
Water Environment Research Foundation
Jeff C. Moeller, P.E.
Members-At-Large:
James F. Kreissl
Richard J. Otis, Ph.D., P.E.
Jerry Stonebridge
Members of the Rhode Island Independent Contractors and Associates, URI, and Brian Moore, RI DEM.
20 Alternative Wastewater Treatment for Individual Lots
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