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THE HISTORY OF
THE PROJECT
Ducks, geese, elk? These are not
usual inhabitants of a wastewater
treatment system. But in Cannon
Beach, Oregon, particularly in the
fifteen acres of the wooded wetlands
cells of the system, they are a common
sight. How did this come to pass?
Let's look a little closer. The City of
Cannon Beach had a problem—how
to treat and dispose of its wastewater.
With much citizen involvement, a cost-
effective ecologically-interactive waste-
water treatment facility was created.
This Environmental Protection Agency
(EPA) funded "Innovative/Alternative"
treatment system uses an existing
wooded wetland to provide the final
stage of the treatment process.
Here's the story. The three-celled
sewer lagoon complex in existence at
the time of the passage of the Clean
Water Act of 1972 could not meet the
more stringent effluent quality stand-
ards set by the Oregon Department
of Environmental Quality (DEQ).
In response to this situation, the City
began a Facilities Plan. The completed
plan recommended options for system
upgrading which met with considerable
community opposition.
At this point in 1977, a Sewer
Advisory Board was formed. The City
of Cannon Beach is a resort community
and during the tourist season the popu-
lation swells from a permanent size
of 1,200 to many times that number.
Any design considered by the Sewer
Advisory Board would have to be able
to accommodate these large fluctuations
in wastewater flows.
Confrontation led to a City commit-
ment to pursue a biological solution
instead of more high-tech treatment
units to upgrade the treatment system.
The bureaucratic struggle that ensued
lasted eight years and the remarkable
result of these meetings was the consol-
idation of a set of ideas which emerged
as yet another facility plan addendum.
The issues deliberated included: the use
and integrity of the wetlands, elk habitat,
chlorination, point of discharge, birdlife,
the extent of ecological upset, berming
and baffling, fencing costs, and the risks
Confrontation led to a City
commitment to pursue a
biological solution instead of
more high-tech treatment units
to upgrade the treatment system.
Effluent structures during
winter flooding (when wetlands
are typically not operated). .
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Typical vegetation in the
majority of the wetlands
(brush, sedges, and ferns).
W '••i.'j&W." V',%*iV&r.
&• ;«5?»«f ,1^'4-W-?
of using new treatment techniques.
It is a tribute to the professionals
representing the various agencies
involved in these meetings that, in spite
of diverse and sometimes disparate
responsibilities and divergent goals,
negotiations took place in a spirit of
cooperation and compromise sufficient
to allow development of an approvable
treatment scheme.
This scheme, the wetlands marsh
wastewater treatment system, appeared
in draft Facilities Plan Addendum No. 2
in October, 1981 arid became final in
March, 1982. The Plan subsequently
was adopted by the City Council and
approved by all the appropriate agencies
through the State Clearinghouse review
process. Shortly thereafter, a grant
application was completed and submit-
ted to the DEQ and EPA and approval
of funding for the project was granted
in September, 1982.
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DESIGN
How does the treatment facility
work? Contrary to popular
belief, raw sewage, or waste-
water as engineers prefer to call it, is
over 99% pure water. About half of it
comes from toilets and most of the rest
is from kitchen sinks, showers, bathtubs,
and washing machines. The Cannon
Beach treatment system consists of a
four-celled lagoon complex followed by
two wooded wetland cells which serve
as a natural effluent polishing system.
The objective of the wetland treat-
ment is to meet water quality require-
ments with minimal disturbance to the
existing wildlife habitat. Dikes, contain-
ing water control structures, formed the
wetland cells, constituting the only
physical alteration to the natural
wetland. The fifteen acres of wetlands
are primarily red alder, slough sedge
and twinberry, including the remnants
of an old growth spruce forest. These
wetlands act as a natural filter to
complete the treatment process, and the
wildlife is not disturbed.
Design of the wooded wetland waste-
water treatment system, along with
improvements to the existing lagoon
system, began in December, 1982. The
design of treatment system improve-
ments and the wetland system centered
around meeting stringent effluent limi-
tations imposed by the DEQ. Techni-
cally speaking, the wastewater treat-
ment focuses primarily on the reduction
of both biochemical oxygen demand
(BOD) and suspended solids (TSS).
The average monthly limitations were
10 mg/1 of BOD and TSS during dry
1998 Dry Weather Design
Population, Flows and Loading
Population Equivalents 4065
Lagoons
Flow
Ave. Detention Time
BOD
TSS
Wooded Wetland
Flow
BOD
TSS
0.68 mgd
7-15 days
817lbs/day
817lbs/day
0.42 g/ac/day
~l4Tbs/ac/day
18lbs/ac/day
weather and 30 mg/1
of BOD and 50 mg/1
of TSS above
Ecola Creek back-
ground levels during
wet weather.
The principal mech-
anisms in achieving
BOD and TSS reduc-
tions in wetland systems are sedimenta-
tion and microbial metabolism. Absence
of sunlight in the canopy covered
wooded wetland contributes to signi-
ficant algae die-off and subsequent
decomposition. The two-celled wetland
system was designed with multiple influ-
ent ports into the first cell, multiple
gravity overflow into the second cell,
and a single discharge from the second
cell to Ecola Creek. Each cell was
designed with approximately 8.0 acres
surface area to be operated in series.
Improvements to the existing lagoon
system were to provide capacity through Effluent structures and
. •« 1 • __.__.C^ C\f\O Tl* n-r-r ft n t-» + /^ -V*C± f\ . , 1 . 1 • . .
the design year of 1998. They centered
around three major improvements:
upgrading the hydraulic capacity of the
system; decreasing the loading to the
facultative lagoon system with the addi-
tion of an aerated lagoon; and adding a
chlorine contact chamber to provide
adequate disinfection before discharging
to the wetland marsh system.
The operational strategy developed
around: 1) operating the upgraded
facultative lagoon system during the
wet weather period of the year, and 2)
operating the aerated/facultative lagoon
system along with the wooded wetland
system during the dry weather season.
vegetation located in
north dike.
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V--
cl WOP
AB ....
1,2,3
S
. Aeration Basin
. Facultative lagoons
. Sludge disposal pits
C Chlorine contact chamber
WOP , Winter outfall pipe
Cell 1, Cell 2 .... Wetland treatment cells
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CONSTRUCTION AND OPERATION
Construction of the wastewater
facility improvements began in
July 1983 and the facility offi-
cially began operation in June 1984
when flows from the facultative lagoons
were initially pumped into the wetland.
The system was initially operated with
the aerated lagoon effluent flowing in
series to the three facultative lagoons,
with chlorinated effluent pumped to the
wetland cells which were operated in
series. The discharge from the system
into Ecola Creek is approximately
25% to 50% of the influent flow with
the remainder lost through evapotran-
spiration and seepage. The wetlands
cells were initially operated at an
approximate average depth of one foot
and a detention time of 10-14 days.
Lagoon effluent BOD and TSS have
averaged 27 mg/1 and 51 mg/1 respec-
tively, while the wetlands effluent BOD
and TSS averaged 6 mg/1 and 11 mg/1
respectively. Background water quality
in Ecola Creek has averaged 6 mg/1
BOD and 13 mg/1 TSS. The wetland
removes an average of 12% of the
influent BOD while removing 26% of
influent TSS. Operating efficiency has
improved over time with respect to
BOD and TSS. In 1991, an average of
only 3 mg/1 of BOD was discharged.
For TSS, the past two years have shown
average discharge concentrations of
2 and 5 mg/1 respectively. These rates
were significantly lower than those of
five out of the first six years of operation.
City of Cannon Beach
Wastewater Treatment Facility: Effluent Quality
50-1
40-
Wetlands Effluent
I Background
30-
BOD
(mg/1)
20-
10-
1984 1985 1986 1987 1988 1989 1990 1991
Jul-Oct Aug-Sep Jun-Oct Jul-Oot May-Oct Jun-Nov May-Dot May-Oct
Year
City of Cannon Beach
Wastewater Treatment Facility: Effluent Quality
Wetlands Effluent
| Background
TSS
(mg/l) 40 -
1984 1985 1986 1987 1988 1989 1990 1991
Jul-Oct Aug-Sep Jun-Oct Jul-Oct May-Oct Jun-Nov May-Oct May-Oct
Year
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COSTS AND BENEFITS
The system has been a success.
Performance of the system has
exceeded expectations as the
effluent has come close to meeting the
10/10 effluent limitations without consid-
ering the background water quality. The
City has met its monthly permit require-
ments with only one exception with
respect to concentrations in the first
eight years of operation. The water qual-
ity impact on the creek has been signifi-
cant, only 25% of the mass discharge
loading directly reaches the creek.
The capital costs of the total system
improvements were $1.5 million in
1983. Of that, approximately 40% was
classified innovative and alternative
under the provisions of the Federal
Clean Water Act, thus higher funding
was provided by EPA. The City received
an approximate 80% grant from the
EPA. A significant portion of the City's
share has been financed through a loan
from Farmers Home Administration.
The total Sewer Department's 1992-
1993 budget is approximately $600,000.
The total operational costs of the pond/
wetland treatment facility represents
approximately 12% of this figure. Staff
includes one full-time operator who
devotes approximately half of Ms time
to plant operation and laboratory work,
a weekend public works utility person,
and a summer student intern.
Sewer billings are based on water
usage, using a base rate of $7.50 for
the first 6QO cubic feet and $1.25 for
each additional 100 cubic feet. This
rate has remained unchanged since
1983. A 10% across-the-board increase
is currently under consideration.
Elk browse on their long-time
path to Ecola Creek, along the
edge of the wooded wastewater
wetland, just 700 feet from ~
downtown Cannon Beach.
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A NATURE STUDY SITE
Treatment of facultative lagoon
effluent through the use of a
natural wooded wetland has been
demonstrated as an effective method
over the eight years of operation. The
City's direct discharge to Ecola Creek
has been reduced and it's quality has
been improved resulting in unproved
water quality for the creek. The capital,
operation, and maintenance costs utiliz-
ing the wetland treatment system are
significantly less than alternative
systems. The treatment lagoons and
wetland cells are a physical reality and
an integral part of the City. Involvement
in this sewerage project has resulted in
a heightened awareness of the physical
setting in which we live, the biological
processes of which we are a part, and
the society in which we function.
The City has cooperated with the
school system in setting up a partner-
ship. Educational materials that inte-
grate social studies and science have
been developed cooperatively using a
City liaison person and resource
teacher. As well as serving as a nature
study site, the treatment marsh has
been the focus of programs, devised by
Citizen Education. Waterfowl have
been monitored by citizen effort. Tours ,
are conducted for environmentally
oriented classes; for groups of teachers,
for sewer operators, for those seeking
wastewater treatment solutions for their
communities and for local citizens, as
well as any interested individuals.
The organic nature of the sewerage
facilities, the lack of offensive odor
and the open layout of the facility
contribute to a land use scheme that
has a minimal disruption to the environ-
ment. Very few visitors realize that
the City's sewerage facilities are just
700 feet from the downtown shopping
area! Within the site, the stream flows,
trees and plants grow, and animals and
birds come and go. Numerous species of
wild ducks can be seen on the lagoons,
elk can be seen hi the wetlands area,
fishing, walking, and bird watching take
place here.
This brochure is dedicated to the memory of
Don Thompson, "The Thinker and the Doer
of the Cannon Beach Sewer."
Contributors—Dan Elek, Jerry Minor and
Francesca Dethgen
Produced by—Woodward-Clyde Consultants
Graphic Design—Chris Dunn
EPA Project Manager—Robert Bastian
Within the site, the stream
flows, trees and plants grow,
and animals and birds come
and go.
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