Ecological Research Series
STUDIES ON LAKE RESTORATION BY
PHOSPHORUS INACTIVATION
Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Corvallis, Oregon 97330
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into five series. These five broad
categories were established to facilitate further development and application of
environmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The five series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. ,, Socioeconomic Environmental Studies
\
This report has been assigned to the ECOLOGICAL RESEARCH series. This series
describes research on the effects of pollution on humans, plant and animal
species, and materials. Problems are assessed for their long- and short-term
influences. Investigations include formation, transport, and pathway studies to
determine the fate of pollutants and their effects. This work provides the technical
basis for setting standards to minimize undesirable changes in living organisms
in the aquatic, terrestrial, and atmospheric environments.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/3-76-041
April 1976
STUDIES ON LAKE RESTORATION BY PHOSPHORUS INACTIVATION
by
William D. Sanvilie
Arnold R. Gahler
Julie A. Searcy
Charles F. Powers
Ecological Effects Research Division
Corvallis Environmental Research Laboratory
Corvallis, Oregon 97330
U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
CORVALLIS ENVIRONMENTAL RESEARCH LABORATORY
CORVALLIS, OREGON 97330
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DISCLAIMER
This report has been reviewed by the Corvallis Environmental
Research Laboratory, U. S. Environmental Protection Agency, and
approved for publication. Mention of trade names or commercial
products does not consitiute endorsement or recommendation for use
by the U. S. Environmental Protection Agency.
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CONTENTS
Sections Page
List of Figures iv
List of Tables v
Acknowledgements vi
I Introduction 1
II Summary 9
III Conclusions 10
IV Recommendations 11
V Methods and Materials 12
VI Results 14
VII Discussion 39
VIII Comparison of Results with the 1969 Aeration Study 41
IX Addendum - 1972 42
X References 44
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LIST OF FIGURES
No. Page
1 Bathymetric map of Clines Pond showing sampling sites 4
2 Total phosphorus-surface 18
3 Total phosphorus-bottom 19
4 Orthophosphate-phosphorus-surface 20
5 Orthophosphate-phosphorus-bottom 22
6 Ammonia-surface 23
7 Ammonia-bottom 24
8 Total Kjeldahl nitrogen-surface 25
9 Total Kjeldahl nitrogen-bottom 26
10 Soluble iron-surface and bottom 28
11 Soluble manganese-surface and bottom 29
12 Alkalinity-surface 30
13 Alkalinity-bottom 31
14 Oxygen (% saturation)-surface 33
15 Oxygen (% saturation)-middle 34
16 Oxygen (% saturation)-bottom 35
17 pH-surface 36
18 Water transparency 37
19 Chlorophyll a-average of surface and bottom 38
20 Phytoplankton-total clump count-average of surface
and bottom 40
21 Phytoplankton-modified clump count-average of surface
and bottom 41
IV
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LIST OF TABLES
No. Page
1 Reduction in total phosphorus and soluble silica in 3
a natural soft water by treatment with metal salts
2 Summary of Cline's Pond limnological data 6
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ACKNOWLEDGEMENTS
We thank Richard Whitmer and Kevin Drost who aided in the application
of the sodium aluminate and the collection of field data and Gerald Schuytema
and Donald Hatler for the many hours spent enumerating the phytoplankton
samples.
Special appreciation is given to Lester, Maria and Lee Roy Cline for
use of their pond as the experimental site.
VI
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SECTION I
INTRODUCTION
Reduction of in-lake nutrient levels through nutrient inactivation
is one technique being evaluated for the restoration of excessively
eutrophic lakes. Such treatment may be required for numerous shallow
lakes or ponds and those lakes possessing poor flushing characteristics,
even though external supplies of excess nutrients are prevented from
entering the system. The advantages of nutrient inactivation over other
restoration methods are relatively low cost, ease of application, wide
scope of applicability, and use of low or non-toxic chemical or mineral
additives (as compared with the use of copper sulfate or algicides, for
example). Selected metal ions have shown potential as nutrient inactiva-
tion substances. These have the disadvantage of forming flocculent
hydrous oxides which may be resuspended by wave action and currents in
shallow lakes. Also, bacterial solubilization of phosphates of aluminum,
calcium, and iron may occur under some conditions (1, 2, 3, 4, 5).
Harrison et al., (6) have shown that sediment bacteria from Upper Klamath
Lake, Oregon, are able to liberate phosphate from normally insoluble
phosphates under anaerobic conditions. Such activity could hamper
efforts toward permanent lake restoration by nutrient inactivation using
metal ions, but periodic rejuvenation could be accomplished by subsequent
additional treatments. Also, such resolubilization might not constitute
as significant a problem in deep, stratified lakes.
Existing technology of potential applicability to nutrient inacti-
vation is oriented toward the removal or immobilization of phosphorus.
Numerous methods, mostly based on chemical precipitation or ion-exchange
mechanisms, effectively remove phosphrous from sewage effluents (7, 8).
Chemical methods include treatment with lime, alum, alum-lime, and iron
(1). Fly ash has been found by Tenny and Echelberger (9) to significantly
decrease phosphorus concentrations in water from highly eutrophic Stone
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Lake, Michigan. In 1968, Lake Langsjon, Sweden, was treated with Boliden
pellets (primarily aluminum sulfate) (10, 11). The lake showed definite
improvement with a reduction in algal blooms during the summer following
treatment; however, a second treatment in 1970 was necessitated because
of additional sewage inflow to the lake. In 1970, Horseshoe Lake,
Wisconsin, appeared to be improved by treatment with alum (12). A
decrease in total phosphorus was apparent, hypolimnetic phosphorus
concentrations did not increase during thermal stratification, trans-
parency increased slightly, dissolved oxygen remained higher, and nuisance
algal blooms which occurred in previous years were absent following
treatment.
In 1969, an investigation was begun in our laboratory to determine
the practicality of nutrient inactivation by chemical methods. The
studies were designed to determine the total phosphorus removal capabili-
ties of various chemical substances in both laboratory and field situations
In a 1974 publication, Peterson et al. (13) describe a more extensive
laboratory evaluation of chemical inactivants which was conducted in
this laboratory subsequent to the study being described in this report.
Aquarium experiments were used in 1969 to test the effectiveness of
aluminum, lanthanum, calcium, and zirconium hydroxides in decreasing
phosphorus concentration in waters from eutrophic lakes in Oregon. In
all cases, phosphorus concentration and algal production were greatly
reduced. Some reduction of soluble silica was also accomplished. The
chemical results of these experiments are summarized in Table 1.
In 1970, limited field tests were conducted using two nylon-
reinforced polyvinylchloride (PVC) enclosures measuring 4.8 x 4.8 x 3.6
m deep (16 x 16 x 12 feet). Both enclosures were open at the bottom
and, when placed in the pond, effectively isolated two water columns and
contiguous bottom sediments. Aluminum sulfate (10 mg Al/1) was added to
enclosure A, and enclosure B (Figure 1) served as a control. Results of
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TABLE 1. REDUCTION IN TOTAL PHOSPHORUS AND SOLUBLE SILICA IN A NATURAL SOFT WATER BY TREATMENT WITH
METAL SALTS (ALKALINITY 60-70 mg CaC03/l)
Metal
Al
Al
Al
Al
La
La
Zr
Zr
Solution of
Chemical
Added
Boliden Pellets
NaA102
Boliden Pellets
NaA102
LaCl3
LaCl3
ZrOCl2
ZrOCl9
Concen-
tration
(mg metal/1 )
2.5
5.0
50.0
50.0
5.0
50.0
4.4
50.0
Total
Phosphorus
(mg P/l
before
treatment)
0.26
0.16
0.16
0.16
0.15
0.12
0.26
0.56
Total
Phosphorus
(mg P/l
after
treatment)
<0.01
0.03
<0.01
<0.01
0.06
0.04
<0.01
0.04
Soluble
Silica
(mg SiO /I
before
treatment)
32
39
39
40
Soluble
Silica
(mg SiO?/l
after
treatment)
20
16
8
32
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A-Treated Pool
B-Control Pool
SI.S2
Sampling Sites
85m
1
(N
0 5 10
55m
Meters
FIGURE 1. Bathemetric map of Cline's Pond showing sampling sites
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these tests were inconclusive, primarily because of a tendency for the
enclosed water to stagnate relative to the open pond. However, phytoplank-
ton numbers and chlorphyll ^concentrations in the treated enclosure
were lower than in the control. Total carbon and total Kjeldahl nitrogen
were also lower in the experimental enclosure, again indicating decreased
production. Pronounced differences in phosphorus concentrations in the
two enclosures were not observed.
We decided to extend our studies to a field evaluation of nutrient
inactivation. The objectives were three-fold: (1) to scavenge the
phosphorus, (2) to prevent the return of soluble phosphorus from the
sediment interstitial water to the overlying water, and (3) to observe
the effect of the treatment upon the biota of the pond.
Cline's pond, a 0.4 ha (1 acre) pond constructed in 1953 and located
approximately 32 km (20 miles) north of Corvallis, Oregon, was selected
as the experimental site. The pond received surface runoff from a 1 ha
(2.5 acre) drainage area which is usually planted in a forage crop or
sugar beets. Several small, intermittent springs supplied some subsurface
water; other possible ground water infiltration was not evaluated. The
maximum depth was 4.9 m (16 ft) with an average depth of 2.4 m (8 ft)
(Figure 1). The pond was stocked annually by the owner with 8-10 cm (3-
4 inch) rainbow trout finger!ings which were fed between 90-140 kg (200-
300 pounds) of commercial fish food each year. Limnological data had
been collected on the pond for three years and indicated a high degree
of eutrophy; heavy growths of blue-green algae had occurred routinely,
and severe oxygen depletion, high nutrient levels, and low water trans-
parency had been the norm. Summer thermal stratification occurred in
the deeper parts of the pond, and mild winter temperatures usually
precluded the pond's freezing over. Limnological data for 1969, 1970,
and 1971 are shown in Table 2.
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TABLE 2. SUMMARY OF CLINE'S POND LIMNOLOGICAL DATA
Depth3 'b
P-total (mg/1)
P-ortho (mg/1)
N-ammonia (mg/1 )
N-nitrate (mg/1)
N-nitrite (mg/1 )
N-total Kjeldahl (mg/1)
C-total (mg/1)
C-soluble organic (mg/1)
Fe-soluble (mg/1 )
Fe-total (mg/1)
Mn-soluble (mg/1)
Mn-total (mg/1)
Si-soluble (mg/1)
Alkalinity (mg CaCOyi)
DO (% Saturation)
DO (mg/1)
PH
S
B
S
B
S
B
SB
SB
SB
SB
SB
SB
SB
SB
SB
SB
SB
S
M
B
S
M
B
S
B
1971
4/15-9/15
Avg.
.06
.09
.01
.01
.03
.03
<.01
<.002
1.1
15
8
.16
.78
.20
.56
3.3
32
no
99
32
10.0
9.2
3.2
7.4
7.0
Min-Max.
.01 -
.02 -
<.01 -
<.01 -
<.01 -
<.01 -
<.01 -
<.002-
.5 -
8 -
2 -
.02 -
.30 -
<.01 -
.10 -
1.5 -
22 -
77 -
67 -
2 -
7.0 -
6.1 -
.0 -
6.5 -
6.5 -
.11
.33
.02
.02
.13
.15
.09
.007
2.5
28
16
.63
3.50
1.30
1.58
5.9
47
152
122
96
13.4
11.1
9.7
9.5
7.5
1970
4/15-9/15
Avg.
.29
.35
.03
.09
.22
.56
<.01
.003
2.6
22
6
.92
1.84
.78
.74
6.3
46
98
41
9
8.4
3.7
.8
8.8
7.2
Min-Max
.13 - .60
.18 - .48
<.01 - .09
<.01 - .28
<.01 - .84
<.01 - 1.40
<.01 - .04
<.002- .009
.9 - 7.0
8 - 34
2 - 14
.20 - 1.70
.50 - 3.70
<.01 - 1.95
.12 - 1.35
1.7 - 11.0
31 - 61
22 - 200
9 - 96
2 - 17
2.0 - 16.5
.9 - 8.7
.2 - 1.7
6.7 - 10.9
6.4 - 8.9
1969 Control
4/15-9/15
Avg.
.17
.56
.01
.02
.05
.95
.04
.010
2.5
46
126
62
19
10.8
5.7
1.7
8.7
6.8
Min-Max
.09 - .30
.14 - 1.85
<.01 - .04
<.01 - .05
.02 - .07
.08 - 4.25
<.01 - .10
.004- .010
1.3 - 9.1
33 - 76
73 - 197
7 - 117
0 - 69
6.2 - 16.1
.6 - 10.4
.0 - 6.4
7.7 - 9.6
6.5 - 8.2
1969 Aerated 1971
6/30-9/15 6/30-9/15
Avg.
.19
.44
.02
.03
.21
.71
.0.1
.010
2.5
46
124
56
17
10.4
5.6
1.6
6.9
6.6
Min-Max
.09 - .36
.12 - 1.55
<.01 - .07
<.01 - .06
.04 - .10
.04 - 4.25
<.01 - .03
.004- .120
1.1 - 8.9
27 - 86
30 - 125
24 - 86
0 - 80
2-7 - 11.1
2.1 - 7.6
.0 - 7.0
6.4 - 8.4
6.3 - 7.0
Avg.
.08
.09
.01
.02
.03
.05
<.01
<.002
1.5
38
116
96
25
10.0
7.8
2.3
7.7
7.0
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TABLE 2. SUMMARY OF CLINE'S POND LIMNOLOGICAL DATA (continued)
Depth3 'b
Secchi disc (cm)
Temperature (°C)
Chlorophyll a
(mg/m )
Phytoplankton
clump count
modified clump
count
Chloride (mg/1)
Sodium (mg/1)
Potassium (mg/1 )
Sulfate (mg/1)
Total hardness (mg/1)
Conducti vi ty (umhos/cm )
Volatile suspended solids
(mg/1)
Suspended solids (mg/1)
S
M
B
SB
SB
SB
SB
SB
SB
SB
SB
SB
SB
SB
1971
4/15-9/15
Avg.
117
18.6
18.0
15.8
54
17,698
42,561
12.0
10.9
.4
<10
34
120
4.7
6.7
Min-Max.
55 -200
11.0- 25.
11.0- 24.
10.0- 21.
2 -179
9.0- 16.
8.9- 16.
.2- .
<10 -<10
25 - 55
160 -138
1.0- 20.
1.0- 28.
1970
4/15-9/15
Avg.
90
8 21.7
8 18.7
5 15.4
187
26,740
192,563
0 4.0
0 7.0
7
10
40
117
0 8.0
0 12.0
1969 Control 1969 Aerated 1971
4/15-9/15 6/30-9/15 6/30-9/15
Min-Max Avg.
12
17
15
11
8
4
5
<10
34
99
1
1
-180 46
.0- 28.5 21.5
.5- 21.1 18.5
.7- 19.8 17.6
-1682 56
20,526
50,188
.0- 4.0
.0- 8.0
-<10
- 46 39
-135 111
.0- 28.0
.0- 36.0
Min-Max Avg. Min-Max Avg.
30 - 75 74 40 ^130 125
15.1- 27.2 22.1 18.6- 22.5 21.6
13.3- 22.1 19.5 18.0- 22.5 20.7
10.4- 21.2 18.6 16.0- 22.4 18.7
27 -117 26 13 - 55 49
17,511 5,433
22,995 58,005
33 - 52 41 34 - 58 39
93 -157 115 101 -181 126
S, surface; M, middle; and B, bottom.
DSB, average of surface and bottom.
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In 1969, Cline's Pond was the site of an aeration-destratification
experiment; this study has been reported by Malueg et al. (14). The
pond was separated into equal experimental and control sections with
polyethylene sheets. The experimental section was aerated and the other
was left undisturbed as a control. Unless otherwise indicated, 1969
data referred to in the present report apply only to the control section.
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SECTION II
SUMMARY
Sodium aluminate effectiveness as a nutrient inactivant to control
eutrophication was evaluated in Cline's Pond, a 0.4 ha farm pond near
Con/all is, Oregon. Ability of the inactivant to scavenge phosphate in
the water column, to prevent resolublization of phosphate, and to inhibit
primary production was of primary concern. Evaluation was based on
limnological comparison of the pond following inactivation with antecedent
data obtained over the preceding two years. In general, total phosphate,
ammonia, total Kjeldahl nitrogen, iron, manganese, and algal standing
crop were lower following inactivation than during the two previous
years. Increased transparency and more uniform distribution of dissolved
oxygen and pH suggested an improvement in water quality. A shift in
dominance from blue-green to green algae was indicated. Firm conclusions
as to the effectiveness of the sodium aluminate treatment cannot be
drawn, however, because of a lack of uniformity of limnological parameters
in the pond during the two years before initiation of the experiment.
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SECTION III
CONCLUSIONS
Data obtained from this study and others using similar techniques
indicate that the use of chemical substances to immobilize algal nutrients
may be a feasible and practical technique for reducing primary produc-
tivity, in eutrophic lakes. The experiment reported here suggested some
reduction in both biological and chemical symptoms of advanced eutrophy,
using an aluminum compound to decrease the availability of phosphorus in
the system. The necessity of comparing the 1971 results with antecedent
data make the results difficult to interpret. Variation in the chemical
and biological data of the latter are sometimes greater than between
these and the 1971 experimental data. Overall, it appears that the
aluminum treatment did reduce the eutrophic status of the pond and that
no obvious toxicity problems resulted. The method does appear promising
for restoration of eutrophic lakes lacking significant flowthrough,
where nutrient influx can be controlled. In other cases where nutrient
input is not curtailed or internal recycling continues, inactivation
treatment on some periodic basis might prove feasable.
10
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SECTION IV
RECOMMENDATIONS
Further studies should be conducted using a variety of possible
nutrient inactivation compounds. This will require extensive laboratory
experimentation to determine efficiencies, duration of effectiveness,
and possible adverse environmental effects. Field testing and prolonged
observation will be necessary to determine effectiveness in the natural
environment where an array of factors, impossible to duplicate in labor-
atory testing situations, may occur.
Nutrient inactivation appears to be a promising tool for reducing
the severity of algal blooms in excessively eutrophic waters. It should
be particularly valuable in situations where nutrient input has been
reduced and a recycling of nutrients between the water and sediment
prevents a reduction in algal productivity. Application of a low or
non-toxic inactivant on a periodic basis may prove a valuable management
tool where non-point sources cannot be controlled. However, use of this
technique should be carefully evaluated because our present knowledge
does not allow the prediction of long range environmental effects.
Additions of foreign materials to a water body should be considered only
when all other possibilities have been evaluated.
11
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SECTION V
METHODS AND MATERIALS
On April 15, 1971, prior to the development of a major blue-green
algal population, the pond was treated with sodium aluminate. The pond
water was poorly buffered (total alkalinity approximately 30-50 mg/1 as
Ca(XL) and the sodium aluminate solution had to be neutralized with
concentrated hydrochloric acid prior to its introduction into the pond
to prevent drastic changes in pH. Sodium aluminate (NaAlO,,) was dissolved
in pond water in 200 1 (55 gallon) metal drums. The neutralized slurry
of aluminum hydroxide and water was pumped to a second metal drum in a
small boat. Distribution from the boat was initially through a 3 m (10
ft) perforated PVC manifold system clamped to the transom. The slurry
was released about 0.3 m (1 ft) below the surface of the water through a
series of spray nozzles. However, the nozzles clogged after about one
half of the solution had been applied and the remaining slurry was
sprayed directly on the water surface from an open hose. Mixing was
achieved by the backwash of the boat propeller during application and by
rapid traverses of the pond after application was completed. A total of
227 kg (500 Ib) of sodium aluminate and 265 kg (585 Ib) of hydrochloric
acid were used in the treatment, corresponding to a final average concentra^
tion in the pond of 10 mg Al/1. The 1971 cost for the sodium aluminate
and hydrochloric acid were $102.00 and $60.00, respectively.
Water samples were collected from two locations, SI and S2 (Figure
1), which were three and four m deep, respectively. Samples for chloro-
phyll a^ and phytoplankton were collected from the surface, middle and
bottom of each location, and samples for chemical analyses were collected
only from the surface and bottom. Chlorophyll a, pH, and Secchi disc
12
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measurements were made weekly. The remaining chemical, physical and
biological determinations (see Table 2) were on a biweekly schedule.
All parameters were measured one week prior to treatment, the day
following treatment, one week from the day of treatment, and every two
weeks thereafter. Chemical analyses were conducted in accordance with
EPA methods (15). Transparency was measured with a black and white 20cm
Secchi disc, dissolved oxygen and temperature with an Electronic Instru-
ments Limited Model 15A Dissolved Oxygen Meter, pH with a Beckman Zero-
matic II pH meter, and conductivity with an Industrial Instruments,
Inc., Model RC 16B2 Conductivity Bridge. Chlorophyll a_ analysis followed
the method of Strickland and Parsons (16).
Phytoplankton were preserved as a three percent formalin mixture
and the preserved samples were counted using a one ml Sedgewick Rafter
counting chamber. Most organisms were identified to genus and some of
the more abundant forms to species. Two different methods were used in
interpreting the phytoplankton data. Originally enumeration was by the
standard clump count (17), but a "modified clump count" was subsequently
employed to obtain a better estimate of actual cell numbers. The standard
clump count considers all organisms of one type in contact with one
another as single organisms, thus generally underestimating the number
of cells, particularly where filamentous or colonial forms are involved.
The filamentous bluegreen Anabaena was the major bloom-forming organism
in Cline's Pond. In order to emphasize its cell numbers rather than
chain numbers, an average number of cells was determinated for approxi-
mately 100 chains. This was multiplied by the total number of chains
counted in each sample to determine the number of cells present. This
method is referred to as the modified clump count."
13
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SECTION VI
RESULTS
Averages of the sampling depths (surface, bottom, or surface and
bottom) at sites SI and S2 are presented in Figures 2 through 21 and
Table 2. Maximum and minimum values are also given in Table 2 to suggest
the magnitude of observed variation. The data used in the comparison
extend from April 15 to September 15 of each year.
Total phosphorus concentrations, which were of particular interest,
did not change greatly immediately after treatment. The average for the
surface at the two stations was 0.043 mg P/l one week prior to treatment
and 0.041 mg P/l one day after treatment. There was an increase from
0.027 to 0.076 mg P/l in the average total phosphorus concentration in
the bottom water of stations SI and S2 during the same time periods;
this increase was confined almost totally to the bottom of the deeper
east station where the total phosphorus increased from 0.020 to 0.104 mg
P/l. In the shallower west station, levels were 0.034 mg P/l before
treatment and 0.048 mg P/l after treatment. Total phosphorus concentra-
tion in 1971 remained lower and did not fluctuate to the degree observed
in the previous two years (Figures 2 and 3).
The 1971 orthophosphate-phosphorus values showed little difference
before or immediately after treatment. Surface samples collected on
April 8, one week prior to treatment, averaged <0.01 mg P/l as did those
collected April 16, the day following treatment. A comparison of averages
of the sampling period indicates practically no differences in orthophos-
phate-phosphorus between the 1971, 1970, and 1969 seasons except for the
1970 bottom samples. Surface orthophosphate-phosphorus concentrations
for three years were 0.01, 0.03, and 0.01 mg P/l, respectively: bottom
concentrations were 0.01, 0.09, and 0.02 mg P/l. Figure 4 indicates the
relative similarity of surface orthophosphate-phosphorus values during
14
-------
0.6 r
0.5
N
CL
E0.4
*
CO
ID
o:
00.3
Q.
CO
O
CLQ.2
0
1971
1970
1969
SURFACE
FEB
M
M
J J
MONTHS
0
N
FIGURE 2. Total phosphorus-surface
-------
2-Or
Q_
8
1-6
1-4
cr
o
x
Q_
CO
O
O
0-6
0-4
0-2
O1
1971
1970
1969
BOTTOM
FEB M
IM J J
' MONTHS
A
0
N
FIGURE 3. Total phosphorus-bottom
16
-------
09r
CL -08
?
07
LU
£ -°6
CO
o
CL -05
O
g -04
CO
CO
o
X
Q_
CO
O
X
Q_
03
02
0
0
1971
1970
1969
SURFACE
FEB M AIM J J
MONTHS
A
0
N
FIGURE 4. Orthophosphate-phosphorus-surface
-------
most of the growth season; Figure 5 shows that bottom values were generally
lower and more stable in 1971.
Ammonia concentrations were generally lower following nutrient
inactivation. No changes were observed immediately after treatment;
values remained between 0.01 and 0.04 mg N/l for the first month. Both
surface and bottom values remained relatively constant throughout 1971
(Figures 6 and 7), never exceeding 0.16 mg N/l throughout the growth
season. The extreme variation in bottom concentrations that occurred in
1969 and 1970 should be noted; on several occasions, the bottom concentra-
tion exceeded 1.00 mg N/l. Average values for the three years illustrate
the same trend: 0.03, 0.22, and 0.05 mg N/l, respectively, for 1971,
1970, and 1969 surface concentrations and 0.03, 0.56 and 0.95 mg N/l for
the bottom.
Nitrite, nitrate, and organic nitrogen did not change greatly after
treatment; nitrite remained <0.001 mg N/l and nitrate varied from <0.01
to 0.03 mg N/l during the initial two months after treatment. Organic
nitrogen decreased from 0.70 to 0.54 mg N/l on the surface and from 0.95
to 0.84 mg N/l on the bottom following sodium aluminate application.
Average nitrite and nitrate concentrations were low during all three
years. Nitrite was <0.002, 0.003, and 0.010 mg N/l, respectively, for
1971, 1970, and 1969, and nitrate was <0.01, 0.04, and 0.01 mg N/l.
Total Kjeldahl nitrogen (Figures 8 and 9) followed a pattern similar to
organic nitrogen, dropping slightly immediately after treatment with an
increase in surface values during mid-July (Figure 8). The surface and
bottom total Kjeldahl nitrogen averages were lower in 1971 than in
either 1970 or 1969: 1.1, 2.6, and 2.5 mg N/l, respectively, for the
three years.
13
-------
28i-
26-
24-
22
1971
1970
1969
BOTTOM
I
II
II
II
ii
E
LiT
Q_
CO
O
X
Q_
O
20
8
I I
CO
CO
z>
cr
o
0
£ -°8
o
X
Q_
06
04
02
0
FEB
M
M J J
MONTHS
0
FIGURE 5. Orthophosphate-phosphorus-bottom
19
-------
.Or
0.8h
2 0.6
E
^0.4
0.2
0
1971
1970
1969
SURFACE
FEB
M
t
M
J J
MONTHS
0
N
FIGURE 6. Ammonia-surface
-------
197
1970
1969
0-4H
O1
FEB M
M J J
MONTHS
A
0
N
FIGURE 7. Ammonia - bottom
-------
7.0r
ro
6.0
5.0
2:
01
£
4.0
3.0
2.0
LU
- 1.0
1971
1970
1969
SURFACE
FEB
M
M
J J
MONTHS
N
FIGURE 8. Total Kjeldahl nitrogen-surface
-------
1971
1970
1969
BOTTOM
lO.Or
ro
CJ
\ 8.0
z:
O>
E
-,"6.0
Q 4.0
LJ
\- 2.0
0
FEB M
M
J J
MONTHS
A
0 N
FIGURE 9. Total Kjeldahl nitrogen-bottom
-------
Total carbon and soluble organic carbon were measured in 1971 and
1970. Concentrations did not change significantly after treatment, but
did increase gradually during the season. Surface and bottom averages
for total carbon were 10 mg C/l before and 9 mg C/l one week after
treatment. A peak of 25 mg C/l was reached on September 7, 1971.
Surface and bottom averages for soluble organic carbon followed a similar
trend; 6 mg C/l before treatment 5 mg C/l after treatment, and a peak of
12 mg C/l on September 7. Average total carbon concentrations were 8.3
mg C/l in 1971 and 6.0 in 1970.
Iron and manganese measurements were not obtained immediately
before or after treatment, nor at any time in 1969. Averages for 1971
were consistently lower than those for 1970 (Figures 10 and 11). Average
soluble iron was 0.16 mg Fe/1 in 1971 and 0.92 in 1970. Total iron
averaged 0.78 mg Fe/1 in 1971 and 1.84 in 1970. Manganese followed a
trend similar to iron. Average soluble manganese was 0.20 mg Mn/1 in
1971 and 0.78 in 1970. Average total manganese was 0.56 mg Mn/1 in 1971
and 0.74 in 1970. The discrepancy in the average soluble and total
manganese values for 1970 cannot be reconciled. The estimated resolution
of the analytical method is 0.01 mg Mn/1.
A slight decrease in soluble silica occurred immediately after the
addition of the sodium aluminate. The surface concentration decreased
from 4.7 mg Si02/l to 3.7 following treatment. The surface-bottom
average for 1971 was 3.3 mg Si02/l and 6.3 for 1970. Soluble silica was
not measured in 1969.
Total alkalinity averaged 24 mg/1 as CaC03 before inactivation at
both the surface and bottom. It remained at that level for about one
month (Figures 12 and 13), increasing to about 40 mg/1 by the end of the
summer. The seasonal averages for 1971, 1970, and 1969 were 32, 46, and
46 mg/1 as CaC03 indicating a slight overall reduction after treatment
of the pond.
24
-------
1-2
1-0
0-8
0-6
0-4
0-2
0
- 2-0
CD
L_
? 1-8
CD
U- 1-6
UJ
_J
CD
Z> 1-4
1971
1970
SURFACE
t
O
(D
1-2
1-0
0-8
0-6
0-4
0-2
BOTTOM
/ \
/
/
I/
APRi M
FIGURE 10.
i
J J A S 0
MONTHS
Soluble iron-surface and bottom
25
N
-------
i-2r
i-O -
0-8-
0-6
0-4
0-2
0
1971
1970
SURFACE
LJ
_l
CD
Z)
_l
o
CO
2-Or
1-8
1-6
,.4
1-2
1-0
0-8
0-6
0-4
0-2
BOTTOM
/
\
/
V^ /
XV ''''"...
/!
; i
/ i
t *
: \
\
\
. \
: A \
J L
APRl M J JASON
I MONTHS
FIGURE 11. Soluble Manganese-surface and bottom
26
-------
ro
60
o"50
u
O
o
E40
230
_
<20
10
1971
1970
1969
SURFACE
MAR
t
M
X
MONTHS
N
FIGURE 12. Alkalinity-surface
-------
ro
CO
90
80
70
o"160
o
o
o
E50
<
_j
<
30
20
1971
1970
1969
BOTTOM
MAR
t
M
J J A
MONTHS
0
N
FIGURE 13. Alkalinity-bottom
-------
The percent saturation of oxygen differed between 1971 and the
previous years (Figures 14, 15, and 16). Surface and mid-depth satura-
tion levels were more uniform after treatment and did not exhibit the
extremes observed in 1970 and 1969. Average saturation values for the
surface, middle, and bottom in 1971 were 110, 99, and 32 percent, respec-
tively. Average values for the same period and depths in 1970 were 98,
41 and 9 percent, and for 1969, they were 126, 62, and 19 percent.
The hydrogen ion concentration (pH) of the water did not change
significantly after treatment with neutralized sodium aluminate. The pH
was 7.0 before treatment and 6.9 the day following. Surface pH remained
nearly constant (between 7.0 and 7.5) well into June (Figure 17). The
data for 1970 and 1969 showed higher averages than 1971. Average sur-
face values for 1971, 1970, and 1969 were 7.4, 8.8, and 8.7; those for
the bottom were 7.0, 7.2 and 6.8.
Transparency was somewhat increased in 1971, particularly compared
to 1969 (Figure 18). The Secchi disc reading immediately before treat-
ment was 177 cm and decreased to 100 cm four hours after treatment. It
increased slightly the following day to 115 cm, and one week following
treatment had increased to 160 cm. The summer average in 1971 was 117
cm as compared to the 1970 average of 90 cm and the 1969 average of 46
cm (Figure 18).
Average water temperatures were similar during the three years,
although the 1971 values were somewhat less. Surface, middle, and
bottom average temperatures (°C) were 18.6, 18.0, 15.8 for 1971; 21.7,
18.7, 15.4 for 1970; and 21.5, 18.5, 17.6 for 1969.
Biological data suggested a slight reduction in standing crop in
1971 compared to the previous years. Chlorophyll a_ (Figure 19) did not
change greatly immediately after treatment. Surface and bottom values
29
-------
1971
1970
1969
SURFACE
200r
o
j=
<
o:
3
h-
601
CO
o
201
LJ
CD
>-
X
O
801
40l
Q
APR
T
M
J A
MONTHS
0
N
FIGURE 14. Oxygen (% saturation) -surface
-------
140
20
O
00
v
0s
UJ
80
60
X 40
O
20
1971
1970
1969
MIDDLE
"APR
M
J A
MONTHS
0
N
FIGURE 15. Oxygen (% saturation) -middle
-------
1971
1970
1969
BOTTOM
lOOr
CO
IN3
O
Q
'APR
f
J A
MONTHS
S
N
FIGURE 16. Oxygen (% saturation) -bottom
-------
00
CO
I2r
10
X
Q. 9
8
MAR
1971
1970
1969
SURFACE
M
J J
MONTHS
N
FIGURE 17. pH - surface
-------
240
CO
200
o 160
0)
Q 120
o
LJ 80
O)
40
0
1971
1970
1969
\
\
\
MAR
A
t
M
MONTHS
0
N
FIGURE 18. Water transparency
-------
1000
800
600
400
"E
_
I
CL
O
o:
o
o
?00
100
80
40
20
10
8
'APR M
f
J
J A
MONTHS
0
N
FIGURE 19. Chlorophyll a^-average of surface and bottom
35
-------
o
one week prior to treatment were 7.3 and 7.2 mg/m , respectively, and
one day after treatment decreased to 6.4 on the surface, but increased
to 9.1 near the bottom. Surface and bottom averages for the three year
period were 43 mg/m3 (1971), 187 mg/m3 (1970), and 54 mg/m3 (1969).
Concentrations of chlorophyll a_ were greatly reduced during the two
months immediately following the application of the sodium aluminate as
compared to the same time interval in 1970 and 1969 (Figure 19).
Indications of a somewhat reduced standing crop were also found in
the phytoplankton counts. Neither the clump count nor the modified
clump count showed a sizable reduction in phytoplankton immediately
after treatment (Figures 20 and 21). On a seasonal basis, however, both
methods of counting suggested a reduction in cell numbers for 1971. The
averages of surface and bottom clump counts for 1971, 1970, and 1969
were 17,000, 26,700, and 20,500 cells/ml, respectively. For the modified
clump count, averages for the same period were 42,500, 192,600, and
50,200 cells/ml.
Figures 20 and 21 indicate the peak algal growth periods. Anabaena
was the predominant blue-green; each year a spring bloom of A. affinis
and a late summer bloom of A. helicoidea occurred. The magnitude of the
blooms was not as great in 1971 as previously. Speciation apparently
changed with the treatment; Catena viridis and Planktosphaeria were
present in 1971, but were not recorded during the previous two years.
Green algal peaks of Ankistrodesmus, Kirchneriella, and Scenedesmus
occurred during midsummer of all years, but the magnitude was greater in
1970 than either 1969 or 1971.
36
-------
1971
1970
1969
Ankistrodesmus
Trochelomonas
APR A M
J A
MONTHS
0
N
FIGURE 20.
Phytoplankton-total clump count-average
of surface and bottom
37
-------
lAnoboeno
'\
to
M
FIGURE 21
J A
MONTHS
Phytoplankton-modified clump count-average
of surface and bottom
38
-------
SECTION VII
DISCUSSION
The chemical, physical, and biological criteria suggested improve-
ment in the water quality of Cline's Pond following addition of sodium
aluminate. Chlorophyll a^ phytoplankton counts and organic nitrogen
seem to indicate a reduced algal standing crop when compared to 1970 and
1969. Secchi disc measurements showed a moderate increase in transparency
in 1971. Dissolved oxygen did not exhibit the large fluctuations,
associated with heavy algal blooms, observed in previous years.
The sodium aluminate addition to Cline's Pond was expected to
directly reduce phosphorus concentrations. Average total phosphorus
decreased markedly following sodium aluminate addition and remained at
low levels throughout the year. This was probably the result of adsorp-
tion or bonding of phosphorus to the aluminum hydroxide floe and precipita-
tion of the particulate matter. However, orthophosphate-phosphorus
levels in 1971 were about the same as those observed in the previous two
years, except that increases that occurred in the mid and late summer in
1970 and 1969 were not observed in 1971.
The substantially lower ammonia levels observed during the 1971
season suggested a reduced level of production, in that there appeared
to exist relatively little decomposable organic matter. Kjeldahl-N was
likewise lower in 1971 than in the preceding two years.
Although a short-term bloom of Anabaena occurred in August after
the sodium aluminate treatment, spring blue-green blooms of Anabaena and
Aphanizomenon as in 1969 and 1970 were not repeated. In 1971, the
spring peak consisted of a filamentous green alga, Catena viridis, and
several other green coccoid forms. As shown by the chlorophyll a values,
the algal biomass during the 1971 spring pulse was less than in previous
39
-------
years. Midsummer levels however, exceeded those which occurred in 1969.
This may be partially explained because the chlorophyll ^analytical
technique employed in 1971 varied somewhat from that in 1969. The
higher midsummer phytoplankton counts can be partially explained by lack
of an accurate conversion factor in 1969. The conversion factor was
calculated after the samples had been stored for two years.
Some changes in algal species composition were noted following
treatment of the pond. Catena viridis, which constituted the 1971
spring pulse, had not been recorded previously as was the case for
Planktosphaeria. Aphanizomenon was important in 1969, decreased in
1970, and was not observed in 1971.
Application of the aluminum hydroxide floe did not appear to result
in any deleterious effects on the observable biota. Rainbow trout
exhibited no signs of stress, and those taken from the pond after treat-
ment were in excellent condition. None of the trout appeared to die as
a result of treatment and some remained for harvesting in the spring of
1972. Data were not collected on the benthos.
One possible adverse effect of neutralized sodium aluminate addition
is an increase in conductivity due to the introduced Na+ and Cl~ ions.
If sufficient buffering capacity is present, addition of a second substance
to neutralize the first may be unnecessary and increases in the conduc-
tivity may not represent a serious problem. In soft water bodies,
particularly where outflow is slight, significant increases in conductivity
might occur if repeated application is necessary.
40
-------
SECTION VIII
COMPARISON OF RESULTS WITH THE 1969 AERATION STUDY
The aeration experiment, referred to earlier, started on June 30,
1969, when aeration of the experimental section began. Mechanical
difficulties delayed the experiment farther into the growing season than
had been intended; therefore, results were not as clearcut as desired.
Table 2 summarizes data relating the findings of the aeration
study. Comparison of results with those of the present nutrient inactiva-
tion study over a comparable period (6/30 to 9/15) yield some interesting
insights into the dynamics of the two techniques. Quantitatively,
standing crop was not affected by the aeration process. A pronounced
qualitative difference in algal forms occurred, but standing crop measure-
ments were about the same in both the experimental and control sections.
Nutrient inactivation seemed to reduce algal biomass and changed the
species composition. In both cases, the apparent change was toward an
increase in the number of green algal forms at the expense of the blue-
greens. Total phosphorus and ammonia were reduced more by the sodium
aluminate addition than by aeration, and orthophosphate-phosphorus
remained lower. The pH of the system, however, was more stab-le during
aeration. Dissolved oxygen remained at higher levels during the present
study than during aeration; this effect could have been a result of
delaying the aeration study until after the occurrence of the spring
algal bloom. This delay may have resulted in an excessive oxygen demand
of the settled and decomposing organic material or resuspension of the
sediment during the aeration process.
41
-------
SECTION IX
ADDENDUM-!972
A much reduced sampling schedule was continued into 1972 in an
effort to determine the long term effectiveness of the sodium aluminate
treatment. Samples were collected on a monthly basis from December,
1971, until the termination of the study in July, 1972. Data collection
beyond this time was impossible because necessary physical modifications
of the pond required draining and removal of accumulated sediments.
Chlorophyll a_, Secchi disc and phytoplankton measurements indicate the
pond returned to a state of relatively high productivity the year following
treatment. The maximum chlorophyll a_ concentrations occurred one month
earlier in 1972, but were of the same magnitude as the 1971 values. A
very qualitative description by one of the project personnel indicated
that the Anabaena bloom observed in 1972 was equal in magnitude to any
previously observed in the pond. The minimum Secchi disc measurements
for 1972 were 45 cm, about the same as observed during the maximum
growth period the previous year.
Phytoplankton data also suggested a shift toward greater eutrophy
the second year; an increase in the number of organisms and a shift
toward a blue-green algal population occurred. Qualitatively, the
spring bloom of green coccoid forms observed during the three previous
years was apparently replaced by a green flagellate population. Catena
viridis, a large portion of the April-June 1971 population, did not
appear in significant numbers in 1972.
Chemical parameters indicated a similar trend. The 1972 nutrient
levels were either comparable to the 1971 levels or somewhat greater.
Total phosphorus values were greater in 1972, but orthophosphate-
phosphorus, soluble silica and inorganic nitrogen were approximately the
same. Data interpretation is difficult because of samples were collected
42
-------
once a month in 1972 as opposed to an average of three times each month
in 1971. Changes resulting from biological processes were impossible to
assess because phytoplankton could develop into bloom populations and
then disintegrate within the sampling interval of 1972.
The infrequency of sampling combined with any modification of the
growth pattern resulting from climatic variation could partially account
for the observed chemical and biological differences between 1971 and
1972. However, the sodium aluminate treatment apparently did not signi-
ficantly reduce algal standing crop the second year. The increased
standing crop could have resulted from a number of factors, but the most
likely are: (1) renewal of nutrients from slope runoff and ground water
from surrounding fertilized fields (2) bacterial degradation of the
precipitate, (3) mixing of the precipitate and sediment so that a seal
no longer covered the bottom sediments or (4) a dilution and loss of the
precipitate resulting from heavy winter rains. Further research will be
necessary before a definitive conclusion can be reached as to the pro-
longed effectiveness of the sodium aluminum treatment.
A concluding observation should note that no long term acute aluminum
toxicity problems developed. Rainbow trout survived into the second
year and a few survived into 1974. A large population of zooplankton
and frogs have remained. Although no quantitative samples were collected,
visual observation suggests a minimal modification of the fauna resulting
from the sodium aluminate addition.
43
-------
SECTION X
REFERENCES
1. Alexander, M. Introduction to Soil Microbiology. New York, John
Wiley and Sons, 1961. p. 358-361.
2. Wood, E. J. F. Marine Microbial Ecology. New York, Reinhold
Publishing Corp., 1965. p. 114-115.
3. Wood, E. 0. F. Microbiology of Oceans and Estuaries. New York,
Elsevier Publishing Co., 1967. p. 102, 267.
4. Johnson, H. W. The Solubilization of "Insoluble" Phosphates. V.
The Action of Some Organic Acids on Iron and Aluminum Phosphates.
New Zealand Journal of Science (Wellington). 2^2):215-218, June,
1959.
5. Sperber, J. I. Solution of Apatite by Soil Microorganisms Producing
Organic Acids. Australian Journal of Agricultural Research (Melbourne),
9J6):782-787, November 1958.
6. Harrison, M. J., R. Y. Morita, and R. E. Pacha. Solubilization of
Inorganic Phosphate by Bacteria from Upper Klamath Lake Sediments.
Limnology and Oceanography. V7(l ):50-57, January 1972.
7. Federal Water Pollution Control Administration. Nutrient Removal
and Advanced Waste Treatment. U.S. Department of the Interior,
Portland, Oregon. February 1969. 226 p.
8. Ames, L. L. Alumina Columns for Selective Removal of Phosphorus
from Wastewaters. Federal Water Pollution Control Administration,
U.S. Department of the Interior, Cincinnati, Ohio. 1969.
44
-------
9. Tenny, M. W. and W. F. Echelberger. Fly Ash Utilization in the
Treatment of Polluted Waters. Presented before: Second Ash Utili-
zation Symposium. Pittsburg, Pennsylvania. March 10-11, 1970.
69 p.
10. Jernelov, A. Phosphate Reduction in Lakes by Precipitation with
Aluminum Sulfate. In: Fifth International Conference in Water
Pollution Research. New York, Pergammon Press Ltd., ]_: I 15/1-1
15/6, 1971.
11. Landner, L. Personal Communication. Swedish Water and Air Pollution
Research Laboratory, Stockholm, Sweden. 1970.
12. Peterson, J. 0., J. P. Wall, T. L. Wirth and S. M. Born. Eutro-
phication Control: Nutrient Inactivation by Chemical Precipitation
at Horseshoe Lake, Wisconsin. Department of Natural Resources,
Madison, Wisconsin. Technical Bulletin No. 62. 1973. 20 p.
13. Peterson, S. A., W. D. Sanville, F. S. Stay, and C. F. Powers.
Nutrient Inactivation as a Lake Restoration Procedure-Laboratory
Investigations. U. S. Environmental Protection Agency. Corvallis,
Oregon. Publication EPA-660/3-74-032. October 1974. 118 p.
14. Malueg, K. W., J. R. Tilstra, D. S. Schults, and C. F. Powers. The
Effects of Induced Aeration Upon Stratification and Eutrophication
Processes in an Oregon Farm Pond. Geophysical Monograph Series
Vol. 17, Man-Made Lakes: Their Problems and Environmental Effects.
W. C. Ackerman, G. F. White, and E. B. Worthington (Eds.). American
Geophysical Union, Washington D.C. 1973. p. 578-587.
15. Methods for Chemical Analysis of Water and Wastes. U.S. Environmental
Protection Agency, Cincinnati, Ohio. 16020--07/71. 1971. 312 p.
45
-------
16. Strickland, J. P. H. and T. R. Parsons. A Manual of Sea Water
Analysis, Second Edition. Fisheries Research Board of Canada,
Ottawa. 1965. p. 117-124.
17. Standard Methods for the Examination of Water and Wastewater.
American Public Health Association, Inc., New York. 1966. p. 662-
665.
46
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
EPORT NO. .
EPA-600/3-76-041
3. RECIPIENT'S ACCESSION* NO.
4. TITLE AND SUBTITLE
Studies on Lake Restoration by Phosphorus
Inactivation
5. REPORT DATE
April 1976
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
W. D. Sanville, A. R. Gahler, J. A. Searcy and
C. F. Powers
8. PERFORMING ORGANIZATION REPORT NO
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Corvallis Environmental Research Laboratory
E.P.A.
200 SW 35th Street
Corvallis, Or 97330
10. PROGRAM ELEMENT NO.
1BA608
11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
Same as 9
13. TYPE OF REPORT AND PERIOD COVERED
Final April 1969-July 1972
&. SPONSORING AGENCY CODE
E.P.A. - O.R.D.
CERL
15. SUPPLEMENTARY NOTES
16. ABSTRACT
Cline's Pond, a 0.4 ha farm pond 32 km north of Corvallis, Oregon, was treated
with sodium aluminate to evaluate a nutrient inactivation technique to control
excessive eutrophication. Primary consideration was given to the evaluation of its
ability to scavenge phosphate in the water column, to the prevention of resolubliza-
tion of phosphate during the growth season, and to the inhibition of primary
production. Interpretation of the results was based on a comparison of limnological
data collected after nutrient inactivation with antecedent information obtained the
two years prior to the present study. This made some of the results rather
ambiguous. However, total phosphate, ammonia, total Kjeldahl nitrogen, iron and
manganese were generally lower and dissolved oxygen, transparency and pH suggested
some improvement in water quality. The algae appeared to shift from a predominantly
blue green to a green population and there was an indication of a reduced algal
standing crop. A comparison is given of the results of an aeration study conducted
on the same pond two years earlier. Continued observation into a second growth
season indicated a reduced effectiveness as compared with the year of treatment.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group
*
Eutrophication;- Algal Control, Nutrient
''
Removal',' Aluminate, Aluminum, Aeration
Inactivation, Cline's
Pond
06 06
3. DISTRIBUTION STATEMENT
Release Unlimited
19. SECURITY .CLASS (This Report)'
Unclassified
20. SECURITY CLASS (This page)
Unclassified
21. NO. OF PAGES
53
22. PRICE
EPA Form 2220-1 (9-73)
47
it U. S. GOVERNMENT PRINTING OFFICE: 1976697-056(80 REGION 10
------- |