&EPA
United States
Environmental Protection
Agency
EPA832-R-93-005d
September 1993
Reuse of Municipal
Wastewater by Volunteer
Freshwater Wetlands
Vermontville, Michigan
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INTRODUCTION
Vermontville is a rural community
located 25 miles southwest of
Lansing. The local maple
syrup industry is active; each year a
festival brings thousands of visitors to
this community of 825 residents.
Vermontville considers itself "the
sweetest little town in Michigan." There
is no evidence of the high growth and
bustle of more urban areas; in fact the
local Amish folk tie up their horses
and buggies on Main Street. Mayor
Beverly Sue Billanueva runs the town
and its only restaurant.
The Clean Water Act of the early
1970's dictated that Vermontville up-
grade its wastewater treatment capabili-
ties. In common with many other small
communities, Verniontville could not
afford to own or operate a "high tech"
physical-chemical wastewater treatment
plant. But it was situated to utilize the
land-intensive natural systems tech-
nology, and decided to do so. In 1972,
they opted for facultative lagoons
followed by seepage beds. Those seep-
age beds unexpectedly became wetlands,
a system which works remarkably well
and is liked by the operators.
Cover: Wetland number one
is bordered by lagoons and
Anderson Highway, and is in
close proximity to an operat-
ing farm. Cattails dominate
the vegetation, with a few
willow shrubs in evidence.
Late summer senescence is in
progress, the cattails are
beginning to turn brown.
Inflow
System Description
The municipal wastewater treatment
system at Vermontville, Michigan
consists of two facultative stabilization
ponds of 10.9 acres (4.4 ha), followed
by four diked surface (flood) irrigation
fields of 11.5 acres (4.6 ha) constructed
on silty-clayey soils. The system is
located on a hill with the ponds upper-
most and the fields at descending
elevations (Figure 1). After 1991, the
nineteenth year of operation, the fields
are totally overgrown with volunteer
emergent aquatic vegetation, mainly
cattail. The system was designed for
0.1 MGD and a life of twenty years.
It is presently operated at about three-
quarters of design capacity.
The Vermontville system was
intended, in the conceptual stages, to
provide phosphorus removal both by
harvesting of terrestrial grasses and by
soil-water contact as wastewater seeps
Figure 1. Layout of the
Vermontville wastewater treat-
ment system. Inflow may be
directed to either of the two
lagoons. The lagoons are
discharged into wetlands 1-3.
Wetland 4 no longer receives a
direct discharge; but seepage
water from the uphill units
re-emerges into wetland 4.
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downward from the irrigation fields.
Up to four inches of water applied over
several hours time once each week
would flood the fields briefly until the
water seeped away. The upper pond
(Lagoon 1, Figure 1), has separate
discharge lines into fields 1 and 2, and
the lower pond.(Lagoon 2) has separate
discharge lines into fields 3 and 4.
Fields 1-4 have all been colonized by
volunteer wetland vegetation, and are
now eutrophic emergent marshes.
Pond-stabilized wastewater is released
into each wetland by gravity flow
through 10-in. (0.25 m) main and
8-in (0.2m) manifold pipe having
several ground level outlets in each
wetland. The lagoons and wetlands are
terraced on a steep hillside (Figure 2),
providing ample driving force for
gravity flow. Should the water level
exceed 6 in. (15.2 cm), water would
overflow to the next wetland by means
of standpipe drain. All applied water
would seep into the ground before
leaving the treatment area.
900
880
860
840
The system is operating nearly in
this manner today. There is a constant
surface overflow from the final wetland,
made up of ground-recycled wastewater
which enters the final field at springs.
The direct surface overflow from
wetland 3 has been taken out of service.
Essentially, the system is a seepage
wetland complex and very similar to a
conventional flood irrigation facility.
The vegetation and relatively small
surface overflow from the final wetland
provides an established system in which
to evaluate the treatment aspects of
seepage combined with lateral flow-
through wetlands, the potential nutrient
removal and wildlife values of these
strictly voluntary wastewater wetland,
and the economics of the system.
A thorough study of water quality and
other aspects of system was conducted
in 1978, by Dr. Jeffrey Sutherland of
Williams and Works and Professor
Frederick Bevis of Grand Valley
University. This work was sponsored
by The National Science Foundation.
Lagoon 1
Figure 2. Cross section of
the Vermontville wastewater
treatment system. The units are
set on a steep hillside, with
large driving forces for the
gravity flow from lagoons to
wetlands. Elevations shown on
the left are in feet above sea
level. Overflow occurs out of
wetland 4 to the right.
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HYDROLOGY
PERMITS
Di
. tiring 1990, approximately 29
|MG of wastewater was intro-
duced into the lagoons. This was
a dry year. Evaporation exceeded rain-
fall and snowmelt, leaving only about
22 MG to discharge to wetlands 1,2,
and 3. There was no lagoon discharge
to wetland 4. About 7 MG were lost
to evaporation in the wetland cells,
13 MG infiltrated to groundwater, and
2 MG overflowed from wetland 4 to
the receiving stream.
Wetland 4 receives its water from
interior springs fed by the groundwater
mound under the upgradient wetlands,
most importantly wetland 3. The direct
discharge to wetland 4 was
discontinued, since it was in
close proximity to the system
outflow point, and was
clearly short-circuiting water
across wetland 4. Effluent
discharged from the system
has therefore passed through
the lagoons, then through the
upper wetlands, the soils
under the site, and finally
through the last wetland.
Ti
I he facility operates under an
NPDES Permit issued by
Michigan DNR. The outflow
from wetland 4 is to an unnamed
tributary of the Thornapple River,
which is protected for agricultural uses,
navigation, industrial water supply,
public water supply at the point of
water intake, warm water fish and total
body contact recreation. There are
presently no industrial dischargers. The
discharge limitations from the treatment
wetlands (Table 1) are set for a design
flow of 0.1 MGD. Discharge is limited
to the ice free high flow periods from
May 1-October 31.
Table 1 . Discharge limitations for the
Vermontville wastewater treatment facility. •
Parameter
• CBOD5
TSS
NH4-N
TP
DO
pH
Dates
4/15-4/30
c /-\ n /o r\
o/ 1 -y/ou
10/1-10/31
4/15-4/30
5/1-10/31
4/15-4/30
5/1-9/30
10/1-10/31
All Year
4/15-4/30
5/1-9/30
10/1-10/31
All Year
Daily Daily 30-Day 7-Day
Minimum Maximum Average Average
25mg/l 17mg/l
14lb/d 21 Ib/d
10 mg/l 5mg/l
4.2 Ib/d 8.3 Ib/d !
16mg/l 11 mg/l
9,2 Ib/d 13.3 Ib/d
20 mg/l 30 mg/l
30 mg/l 45 mg/l
7 mg/l
2.2 mg/l
5 mg/l
1.0 mg/l
0.83 Ib/d
5 mg/l
6 mg/l
5 mg/l
6.5 9.0
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WATER QUALITY
Compliance Monitoring
The overflow from final wetland field
4 contains a fairly constant volume of
effluent which has seeped from the
higher elevation wetlands, flowed
through the ground, and entered field
4 springs. This treated effluent is of high
quality, as is the ground water recovered
from the project's monitoring wells.
The outflow is monitored weekly.
Total suspended solids (TSS) was well
within permit limits at all times during
1990 (Figure 3), indicating that the
wetlands had effectively filtered and
settled particulate material.
Carbonaceous biological oxygen
demand (CBOD) also remained within
30-day average permit limits in 1990,
and there was only one excedance of
the seven-day permit limit of 5 mg/1.
The CBOD load in the surface
discharge was less than 10% of that
allowed by the permit.
Total phosphorus in the surface
discharge was also well within permit
limits, with an average 1990 value of
0.24 mg/1 compared to the permit level
of 1.0 mg/1 (Figure 4). The same was
true for ammonium nitrogen, which
averaged 0.86 mg/1 compared to the 2.2
mg/1 permit requirement. Both phospho-
rus and nitrogen display considerable
variability, which is characteristic of
many wetland systems. The seasonal
trends in ammonium nitrogen^—an
increase followed by a decrease—have
been observed at other sites, and are
therefore probably real. They are likely
due to the changing processes of plant
uptake and decomposition.
Figure 3. Both CBOD and
TSS fluctuate in the outflow
from the wetlands, but the
seasonal averages are quite low;
3.5 mg/lfor CBOD; 4.2 mg/l
for TSS. (Data are for 1990)
20
CBOD, mg/1
TSS, mg/1
r~r~r
120 150
May
180 210 240 270 300
June July August September October
Yearday
Figure 4. The nutrients
phosphorus and ammonium
nitrogen were well within limits
in the wetland outflow in 1990.
The seasonal average total
phosphorus was 0.24 mg/l;
ammonium nitrogen averaged
0.86 mg/l.
2.0_
120 150 180 210 240 270 300
May June July August September October
Yearday
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Dissolved oxygen averaged 7.0 mg/1
in 1990, with a range from 5.4 to 9.4,
which included a four excedances of
minor nature. pH ranged from 6.6 to
7.2, well within the permit range.
Fecal coHform counts (Figure 5)
are within limits for surface water
discharges, but are higher than at other
comparable wetland sites.
Research Results
Some of the more detailed water
quality results for 1978 are summarized
in Figure 6. Greater than two-fold dilu-
tion across the system was evident in
the decreasing chloride concentration
from 280 mg/1 in the effluent to 124 mg/1
in the ground water. Pond effluent was
25% diluted with respect to influent.
Although a few inches of precipitation
in excess of evaporation from the ponds
occurred during the summer, the 25%
dilution was more importantly due to
excessive snow and ice meltwater added
to the ponds in spring 1978. The 25%
dilution between the pond effluent and
the water standing in the wetlands was
due principally to a large number of
sampling dates coinciding with signifi-
cant rainfall. Greater than 20 inches
(50.8 cm) of rain fell in the 4 ]/i months
from June to mid October, which was
approximately 50% higher than the
normal rate. The decrease in concentra-
tion between irrigation fields and
ground water was due to .mixing of
wastewater with more dilute ambient
ground water.
Phosphorus was removed to the
extent of around 97% between the
-1000=
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« 100=
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ffl
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£
10-
i i I i I I i i i i i i i i i i i i i i i i i
120 150 180 210 240 270 300
May June July August September October
Yearday
wetland fields and the ground water,
which was sampled from monitoring
wells placed at depths ranging from
roughly 10 ft. to 25 ft. (3.0 m to 7.6 m)
below the wetland floors. Most removal
of phosphorus occurs in the upper
3 ft. (0.9 m) of soils judging from a
small number of lysimeter samples
which averaged 0.11 mg/1 total P and
0.06 mg/1 ortho-P, with ranges of
0-0.3 mg/1 and 0-0.2 mg/1, respectively.
The average removals of phosphorus
effected in the upper 3 ft. (0.9 m) of
soils were approximately 95%.
Levels of nitrate-nitrogen increased
approximately 60% between the pond
discharge and the wetland standing
water, indicating that aerobic bacteria
were at work in the wetland waters.
On the other hand, the sediments were
anaerobic as evidenced in the fetid
odor which evolved when they were
disturbed. Loss of some of the nitrate
by denitrification was apparently
Figure 5. Fecal coliform
bacteria counts also fluctuate
in the outflow from the
wetlands, but the seasonal
average is quite low; the
geometric mean value was 77.
(Data are for1990)
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occurring. Lysimeter samples showed
nitrate-nitrogen ranging from 0.0 to
0.9 mg/1, which suggested that denitri-
fication of approximately 60% of the
nitrate occurred in the shallow wetland
soils. The ambient ground water
contained higher levels of nitrate-nitro-
gen than did the seeping wastewater,
perhaps indicating some further nitri-
fication during passage through the soil.
Levels of TKN and ammonia-
nitrogen seemed not to change much
between the pond discharge and the
wetland waters. But this constancy was
likely only apparent, with organic
nitrogen and ammonia probably
being produced through anaerobic
decomposition in the wetland sediments
and being consumed in the aerobic
wetland waters.
Incoming Wastewater
TP=5.3
C1=280
TKN=81
N03N=1.3
Lagoon Discharge
TP=1.8
C1=207
TKN=6.5
NO3N=1.0
mtm.
Lysimeter @ 3ft
Groundwater
^01=124
NO3N=1.4
Wetland Discharge
TP=2.1
C1=157
TKN=5.0
NO3N=1.2
mum
Surface
Outflow
TP=0.64
JC1=123
Figure 6. Profiles of water
quality in 1978. Lagoons
and wetlands and soils are
functioning to remove
nutrients in this system.
During the early life of the
facility, there were lagoon
discharges directly to wetland
4; and there was surface
overflow directed from
wetland 3 to wetland 4. This
resulted in some short-circuit-
ing to the surface outflow,
and consequently higher
phosphorus numbers than in
the present mode of operation.
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VEGETATION
WILDLIFE
The wetlands were observed to
contain eight plant communities
in 1978. These included areas
dominated by grassland, duckweed,
cattail and willow. In 1991, the grassland
and duckweed communities were no
longer significant. The wetlands are now
dominated entirely by cattail and willow
shrubs and trees.
Standing crops (above ground plant
parts) for the wetlands varied from a
minimum of 830 to over 2,200 gm/m2 in
the wetlands in 1978. Visual estimates in
1991 indicate that the standing crops are
presently somewhat higher than that
maximum, and more uniform. There
appears to be approximately 3,000
gm/m2 at all locations, not counting
trees. Because the wetlands are located
on an exposed hillside, winds can and do
blow down the cattails. The result is a
patchy stand of cattail, about three
meters in height where it is erect, and
flat on the surface elsewhere.
The phosphorus in the prevailing
cattail standing crop is significant
compared to the phosphorus released
into the wetlands. Cattail harvesting
would therefore be a means of reducing
effluent phosphorus. But harvesting is
not needed for phosphorus removal in
seepage wetland settings where sub-
surface soil types and volumes are
adequate to effect phosphorus removal
before effluent ground water reaches
receiving streams. The expense and
difficulty of harvesting further preclude
its use at Vermontville.
Casual observation reveals the
wastewater-grown wetlands have
significantly added to the
acreage of suitable, adequately isolated
habitat for waterfowl and other wildlife
in the Vermontville area. Natural,
interrupted zones of attached aquatic
plant life fringe the nearby Thornapple
River, but these are narrow, small and
easily accessible to fisherman and
other recreationists. The wastewater
wetlands are part of a restricted public
access area.
The Vermontville volunteer wetland
system created marshland habitat
suitable for waterfowl production other-
wise not present in the immediate area.
Many other types of birds also nest in
the marshes, including red-wing black-
birds, American coot, and American
goldfinch. Waterfowl (blue-winged teal
and mallard), shorebirds (gallinule,
killdeer, lesser yellow-legs, and sand-
piper) and swallows use the wetland
pond system for feeding and/or resting
during their migration. Great blue
heron, green heron, ring-neck pheasant,
and American bittern have also been
seen frequenting the wetlands.
These volunteer wetlands are also
important habitat for numerous
amphibians and reptiles. These include
snapping and painted turtles, garter
and milk snakes, green and leopard
frogs, bullfrogs and American toads.
Muskrats inhabit the wetlands, while
raccoon, whitetail deer, and woodchuck
are seen feeding in the wetlands.
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OPERATING AND MAINTENANCE ACTIVITIES
Very little wetland maintenance
has been required at Vermontville.
The berms are mowed three or
four times per year, for aesthetic reasons
only. Water samples are taken on a
weekly frequency at the surface outflow.
The discharge risers within the wetlands
are visited and cleaned periodically
during the irrigation season. There is
essentially nothing to be vandalized, and
there have been no repairs required.
The dikes are monitored for erosion,
which has not been a significant
problem. Muskrats build lodges and
dig holes in the dikes; and woodchucks
also dig holes in the
berms. Therefore, a
trapper is allowed on
the site to remove these
animals periodically.
The operator also
periodically tears the
muskrat lodges apart.
There are no bare
soil (tilled) areas to
be plugged through
siltation caused by rain
splash, spray irrigation,
or flood-suspension of
inorganic soils. The
Vermontville wetlands
showed buildup of
three or four inches
(0.1 m) or organic
residues largely in the
form of cattail straw
after six irrigation
seasons (1972-78). That
litter mat is still of the
same thickness today,
but is accompanied by a small accretion
of new organic sediments and soils.
There was one attempt to burn the
accumulated detritus, which proved to
be difficult, and of no value in the system
operation or maintenance. The amounts
of this material have not compromised
the freeboard design of the embank-
ments over the system's 19+ year
operational period. Tree control has not
been practiced at Vermontville, and the
wetlands now contain willow trees up to
several meters in height. No hydraulic
problems have been experienced due
to these trees, or any other cause.
Wetland number two contains
more and larger willows.
Together with the narrow
leaved cattail, these two species
dominate the wetland.
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COSTS
CONTACTS
The Vermontville ponds and
wetlands cost $395,000 to build in
1972. Much of this expense was
incurred for grading, because of the
uneven topography of the site.
The operating and maintenance costs
associated with the wetlands portion of
the treatment system are quite low. In
1978, these were approximately $3,500
per year, of which $2,150 was labor and
field costs, and the balance for water
quality analytical services. In 1990, these
same costs totalled about $4,200, includ-
ing $3,400 for labor and field costs.
The treatment system is under
the supervision of Mr. Tony
Wawiernia, Superintendent,
Department of Public Works,
121 South Main Street, Vermontville,
MI 49096. Phone (517) 726-1429.
The designers and engineers for this
facility were Williams and Works, Inc.,
611 Cascade West Parkway S.E.,
Grand Rapids, MI 49506.
Phone (616) 942-9600.
Professor Fred Bevis visits the site
with his students on a regular basis,
and collects information on vegetation
and other aspects of the ecosystem.
Fred is Chairman of the Department of
Biology, Grand Valley State University,
Allendale, MI 49401.
Phone (616) 895-3126.
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The ponds at Vermontville are
set into a hillside that drops
off more than 70 feet. This
view of lagoon 2 shows the
high and wide berms that this
relief necessitates. In late
summer, these are covered with
a profusion of wildflowers.
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FURTHER INFORMATION
The 1978 research work is detailed
in a report to The National
Science Foundation under Grant
No. NSF ENV-20273, May 1978. This
report is available from the National
Technical Information Service. Confer-
ence reprints summarizing the work
were prepared, and may be obtained
by contacting Professor Bevis:
Applied Ecology Group
11628104th Ave.
West Olive, MI 49460-9632
Sutherland, J. C. and F. B. Bevis, 1979.
Reuse of Municipal Wastewater by
Volunteer Fresh-Water Wetlands.
IN: Proceedings of Wetland Reuse
Symposium, Vol. 1, p. 762-781.
AWWA Research Foundation,
Denver, CO.
Bevis, F. B., 1979. "Ecological
Considerations in the Management of
Wastewater-Engendered Volunteer
Wetlands," presented at the Michigan
Wetlands Conference, MacMullan
Center, Higgins Lake, MI.
A brief summary description also may
be found in:
Sutherland, J. C., 1982. "Michigan
Wetland Wastewater Tertiary Treatment
Systems," Chapter 16 in: Water Reuse,
E. J. Middlebrooks, ed., Ann Arbor
Science Publishers, Inc., Ann Arbor, MI.
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