EVALUATION OF EXTENDED AERATION TREATMENT
AT RECREATION AREAS
FEDERAL WATER
POLLUTION CONTROL
ADMINISTRATION
NORTHWEST REGION
PACIFIC NORTHWEST
WATER LADORATORY
CORVALLIS, OREGON
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EVALUATION OF EXTENDED AERATION TREATMENT
AT
RECREATION AREAS
Progress Report
A Technical Projects Report
Prepared by
B. David Clark
Regional Research Studies
Report No. PR-8
United States Department of the Interior
Federal Water Pollution Control Administration, Northwest Region
Pacific Northwest Water Laboratory
Corvallis, Oregon 97330
MARCH 1970
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FEDERAL WATER POLLUTION CONTROL ADMINISTRATION
NORTHWEST REGION, PORTLAND, OREGON
James L. Agee, Regional Director
PACIFIC NORTHWEST WATER LABORATORY
CORVALLIS, OREGON
A. F. Bartsch, Director
NATIONAL THERMAL
POLLUTION RESEARCH
Frank H. Rainwater
NATIONAL COASTAL
POLLUTION RESEARCH
D. J. Baumgartner
BIOLOGICAL EFFECTS
Gerald R. Bouck
TRAINING & MANPOWER
Lyman J. Nielson
NATIONAL EUTROPHICATION
RESEARCH
A. F. Bartsch
WASTE TREATMENT RESEARCH
AND TECHNOLOGY: Paper &
Allied Products, Food
Waste Research, Regional
Research Studies
James R. Boydston
CONSOLIDATED LABORATORY
SERVICES
Daniel F. Krawczyk
WASTE TREATMENT RESEARCH
AND TECHNOLOGY
REGIONAL RESEARCH STUDIES
Donald J. Hernandez, Chief
B. David Clark*
Barry H. Reid
Robert D. Shank!and
Harold W. Thompson
Cecil A. Drotts
Judy K. Burton
*Now assigned to National Coastal Pollution Research
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A Working Paper presents results of
investigations which are to some extent
limited or incomplete. Therefore,
conclusions or recommendations—expressed
or implied—are tentative.
-------
CONTENTS
INTRODUCTION 1
Problem 1
Purpose and Scope 2
Authority 3
Study Area 3
Acknowledgment 4
SUMMARY 7
Findings 7
Conclusions 10
Recommendations 11
STUDY PROCEDURES 13
Flow Measurement 13
Sampling 14
Analysis 16
PLANT DESCRIPTIONS 19
Crystal Mountain 19
Timberline Lodge 21
Billiards Beach 22
Sunset Bay 22
RESULTS 25
Hydraulic Loadings 25
Organic Loadings 30
System Efficiencies 31
Alkalinity and pH 39
Aeration Sludge Analysis 41
Nitrification 42
DISCUSSION 45
System Organics Removal 45
Sludge Synthesis and Endogenous Respiration .... 51
Nitrification-Denitrification 58
Solids Removal 63
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CONTENTS (Continued)
Page
DESIGN CONSIDERATIONS 65
BIBLIOGRAPHY 67
APPENDIX 69
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TABLES
Table Page
1 'Details on Crystal Mountain System 19
2 Details on Timber!ine Lodge System 21
3 Details on Bui lards Beach System 22
4 Details on Sunset Bay System 23
5 Analytical Data Summary 26
6 Summary of Hydraulic and Organic Loadings .... 28
7 Summary of Treatment Plant Removal Efficiencies . 32
8 Ratio of BOD5/VSS and COD/VSS for the Crystal
Mountain MLVSS during surveys of 2/10-19/68 and
4/26-29/68 38
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FIGURES
Figure Page
1 Study Area 5
2 Sampling Unit 15
3 Treatment Plant Flow Diagrams 20
4 Hydraulic and Organic Loadings 27
5 Percent BOD5 and COD Removals and Effluent SS. . 33
6 COD Organic Loading versus COD Removal
Efficiency for Total and Centrifuged
Effluent Samples 35
7 Sludge Volume Index (SVI) versus Loading and
Effluent SS 37
8 Alkalinity and pH Variations 40
9 Organic Loading versus Percent Nitrification . . 43
10 Filtered Effluent COD versus COD Removal Rate. . 43
11 Sludge Growth Curve 53
12 Sludge Age versus BODg Organic Loading 55
13 Sludge Age versus COD Organic Loading 57
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-ABBREVIATIONS
- Temperature, °C
- Five-day Biochemical Oxygen Demand, mg/1
COD - Chemical Oxygen Demand, mg/1
SS - Suspended Solids, mg/1
VSS - Volatile Suspended Solids, mg/1
TPO. - Total Phosphate, mg/1 as P
OP04 - Ortho Phosphate, mg/1 as P
TKN - Total Kjeldahl Nitrogen, mg/1 as N
NH., - Ammonia Nitrogen, mg/1 as N
N0? - Nitrite Nitrogen, mg/1 as N
N03 - Nitrate Nitrogen, mg/1 as N
L
0
- Influent BOD,., mg/1
0
- Effluent BOD., mg/1
0
L' - Influent COD, mg/1
L^ - Effluent COD, mg/1
MLVSS=S, - Aeration Tank Mixed Liquor Volatile Suspended Solids, mg/1
a
t - Aeration Tank Detention Time, days
Se - Effluent VSS, mg/1
T1 - Sludge Age, defined as Ib MLVSS/lb VSS wasted per day
M - BODK Removal Rate, Ib BODK Removed/1 b MLVSS-day = L -L /S t
D 0 063
M1 - COD Removal Rate, Ib COD Removed/1 b MLVSS-day = L1 - L'/S t
0 69
a - Sludge "Synthesis Ratio, Ib VSS Produced/1 b BOD,- Removed
F - BOD. Organic Loading Rate, Ib BOD,/lb MLVSS-day = L /S t
D D o a
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ABBREVIATIONS (Continued)
F1 - COD Organic Loading Rate, Ib COD/1 b MLVSS-day = L'/S t
o a
a1 - Sludge Synthesis Ratio, Ib VSS Produced/1 b COD Removed
b - Endogenous Respiration Rate, Ib VSS Destroyed/day/lb ML VSS
£ - Positive or Negative BODc or COD Removal Constant
Depending on Substrate
R - Linear Regression Analysis Correlation Coefficient
K - BOD5 Removal Rate Coefficient, day
K' - COD Removal Rate Coefficient, day
0 - van't Hoff Arrhenius Temperature Relationship Coefficient
K - -
K-
_
~ Maximum Endogenous Respiration rate, day
$ - Rate of Decay of the Endogenous Respiration rate, day"
SVI j - Sludge Volume Index
DO - Dissolved oxygen, mg/1
Hp - Horsepower
gpd - gallons per day
pH - negative logarithm of the hydrogen ion concentration
Avg - average
c - subscripts refer to centrifugal values
t - refers to total value
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ACKNOWLEDGMENT
The assistance of the Oregon State Highway Department
and Parks Department, the Mt. Hood National Forest, Zig Zag
Ranger Station, and managers at Timber!ine Lodge, Crystal
Mountain, Billiards Beach State Park, and Sunset Bay State
Park is acknowledged.
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INTRODUCTION
Problem
With the trend toward complete water systems and the rapid
present and expected future growth in recreational activities,
the disposal of waste waters from recreation areas has become
a major problem in certain areas and is of concern in all areas
with significant recreation use.
The federal nondegradation policy which, as stated in the
Guidelines for Establishing Water Standards for Interstate Waters—{
says that "In no case will standards providing for less than
existing water quality be acceptable." This has since been
interpreted to allow some degradation where economically justified
but generally can be taken as originally stated.
This policy has a direct effect on the treatment of waste-
water from recreation areas in that it demands essentially complete
treatment of all wastes discharged to a water body. In order to
provide this high level of treatment, sound design criteria must
be developed on the basic characteristics of waste waters from
recreation areas and treatment processes that will function under
extreme loading and temperature conditions and remote areas that
may receive little or no routine operation and maintenance.
Generally, most recreation areas can rely upon the septic tank
and drain-field system of disposal with little or no concern about
direct resultant effects on water quality. However, for many of
the more sophisticated camping areas that have water systems (flush
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2
toilets, showers, and in some cases complete laundry facilities)
the soil conditions are completely inadequate to take the higher
volume of wastewater and alternative methods of disposal must be
used. In many instances, package extended aeration treatment
plants have been selected for treatment because of their low
cost, high efficiency and ease in operation and maintenance.
Whether or not they are efficient and easy to operate and main-
tain has been questioned.
Purpose and Scope
In order to develop basic information and guidelines for use
in the treatment of wastes from recreation areas, the Recreational
Sites Waste Treatment Project was initiated in August 1967 at the
request of the Washington State Water Pollution Control Commsssion
and strongly supported by other state and federal agencies. The
study will be terminated in January 1970.
Specifically, the objectives of the study are to define
basic waste characteristics from recreation areas, evaluate
existing treatment processes and to develop a guide for the
planning and design of wastewater treatment facilities at
recreation areas. The study is being conducted in essentially
three phases:
Phase I: Winter Recreation Area Surveys
Phase II: Summer Recreation Area Surveys
Phase III: Pilot Plant Studies
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A progress report has been published on the basic waste
characteristics at winter recreation areas—(
This paper summarizes the findings of studies conducted
under both Phase I and II to evaluate existing extended aeration
treatment processes, and attempts to define the performance of
these plants under various temperature and loading conditions
and to provide basic information on the biological kinetics necessary
for the design of an extended aeration type biological treatment
system for recreation wastewaters.
Authority
Section 5 of the Federal Water Pollution Control Act, as
amended, authorizes the Secretary of the Interior to conduct
special studies on water pollution problems at the request of
a state or other public agency. The State of Washington has
made such a request through a letter dated July 24, 1967, to
the Federal Water Pollution Control Administration.
The Secretary of the Interior is also authorized through
Executive Order 11288 to assist other Federal agencies in the
abatement and prevention of water pollution.
Study Area
Four sites, two winter sport areas and two summer camping
areas, were selected in Oregon and Washington for study because
of their accessibility and close proximity to the Pacific
Northwest Water Laboratory in Corvallis, Oregon.
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4
The two winter recreation areas included Timber!ine Lodge
on Mt. Hood, approximately 50 miles east of Portland, Oregon, and
Crystal Mountain Ski Area near Mt. Rainier National Park,
approximately 50 miles east of Tacoma, Washington. The two
summer areas included Sunset Bay State Park on the Oregon Coast,
approximately 10 miles southwest of Coos Bay, and Bui lards Beach
State Park, also on the Oregon coast, approximately five miles
north of Bandon. Figure 1 illustrates the location of these
areas.
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PACIFIC
OCEAN
WASHINGTON
5) Crystal
Mountain
Portland ®Timberline Lodge
•Corvallis
OREGON
unset Bay State Park
• Roseburg
ullards Beach State Park
FIGURE I. STUDY AREA
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SUMMARY
Findings
1. At the two ski areas, Timberline Lodge and Crystal
Mountain, hydraulic and organic loadings were highly variable
and extremely low when compared to normal loadings for extended
aeration treatment. However, at the two summer areas, Builards
Beach and Sunset Bay, both hydraulic and organic loadings were
fairly constant due to fairly consistent use, large amounts of
infiltration and high collection system detention times.
2. The organics removal efficiency from all four plants
studied in terms of BOD5 and COD was highly variable and on
an average basis less than that considered for secondary
treatment, i.e. 85 percent removal. At the two ski areas, the
average 8005 removal efficiencies were 80 and 84 percent with a
range from 0 to over 97 percent. At the two summer areas, the
average 8005 removal efficiency was 62 and 73 percent and ranged
from 34 to 89 percent.
3. The SS removal efficiency was also highly variable at
all four plants and varied from less than 0 percent to approxi-
mately 90 percent, with an average value of 58 percent for the
ski areas and 66 percent for the summer areas. Floating sludge
in the final clarifier was noted on several occasions at both
Crystal Mountain and Timberline Lodge.
4. The effluent suspended solids was found to vary directly
with the SVI and inversely with the organic loading over the
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8
range of values encountered in this study. At loading levels
below 0.1 Ib COD/lb MLVSS-day, the SVI increased rapidly with
a concurrent rise in effluent SS.
5. There was a significant reduction in alkalinity
through all four systems studied which generally corresponded
with increased nitrification. It was also noted that the raw
sewage alkalinity at the two ski areas during weekday operation
was considerably less than the average weekend values.
6. At the two ski areas, the pH in the aeration basins
and final effluent decreased significantly, and was extremely
variable with 100 percent changes noted overnight. At the two
summer areas, the effluent pH was low (<6.0) but not as variable
as at the ski areas.
7. Microscopic analysis of the aeration basin activated
sludge at the two ski areas indicated a highly dispersed floe
with active protozoan populations and large numbers of
filamentous fungi. The fungi was identified as Geotrichum
condidum at Crystal Mountain.
8. Percent nitrification through the four systems studied
was significantly less than reported in the literature for
similar organic loading conditions.
9. The organic removal rate was calculated on the basis
of completely mixed activated sludge theory, assuming a rate
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9
proportional to the soluble effluent concentration. COD data
were used for this determination because of the high degree
of nitrification in the effluent of the four plants studied
and its effect on the 6005 test. This total relationship was
assumed to be M1 = K'l_e ± 2 (terms are defined in Abbreviations)
10. For the properly buffered systems, the COD removal
/i/i \
ratev ' was calculated as 0.017/day at 20°C. For the low,
variable pH systems, the rate was considerably lower, approxi-
mately 1/8 that of the normal system, at 0.0022/day at 20°C.
11. The Z term in the total organic removal relationship
was calculated as -0.078 for the properly buffered systems and
-0.072 for the variable pH systems. The negative sign of this
term indicates a nonbiodegradable portion of the influent waste.
12. The rate of sludge production was calculated assuming
steady state conditions, a sludge regrowth rate directly
proportional to substrate concentration, and a variable endogenous
respiration rate dependent on sludge age and temperature. This
gave the relationship
(terms are defined in Abbreviations).
13. The sludge synthesis ratio, a, was calculated as 0.54
Ib VSS Produced/1 b BOD5 removed or 0.33 Ib VSS Produced/1 b COD
removed.
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10
14. The maximum endogenous respiration rate, t> . was
fflaX
calculated as 0.052/day at 20°C with a decay coefficient, $,
of 0.02/day.
Conclusions
1. Overall design of extended aeration activated sludge
systems treating the highly variable recreation wastewater
will result in low organic loadings during low flow periods
that may result in an inefficient system due to pH problems,
nitrification-denitrification, reduced organic removal rate,
and a highly dispersed aeration sludge with poor settling
characteristics.
2. A peak flow rate, on the order of 10 times the
average daily flow, should be considered in the design of
final clarifiers treating recreation wastewaters due to the
possibility of carryover of suspended solids at the higher
peak flow rates.
3. The organic removal rate in terms of COD is highly
dependent on stable pH conditions in the aeration basin of a
biological system and may be severely reduced if conditions
are not stable.
4. The high correlation coefficients obtained through
linear regression analysis of the COD removal data appears to
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11
5. The sludge synthesis ratio (a) is not seriously
affected by unstable low pH conditions.
Recommendations
Where secondary treatment is the desired standard, the
use of extended aeration activated sludge systems for the
treatment of recreation wastes should be discouraged unless
adequate assurance can be given that the plant will be properly
operated and maintained, including proper sludge wasting
facilities and/or an adequately designed solids removal
process is added to the system either in the form of a polishing
pond or a filtration unit.
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STUDY PROCEDURES
Flow Measurement
At Crystal Mountain, flow to the treatment plant was measured
with a 60° V-notch weir installed on the effluent side of the plant
clarifier. A water stage recorder* with a three-day chart was
used to record the weir height which was then converted to flow.
The recorder Was installed on January 12, 1967, and removed on
April 29, 1968.
At Timberline Lodge, wastewater flow is measured continuously
by a 22.5° V-notch weir on the effluent side of the plant chlorine
contact chamber. The recorder is equipped with a totalizer which
was read daily during each survey period.
At Bullards Beach State Park, a water stage recorder* was
installed in the wet-well of a small pump station that precedes
the treatment plant. Flow was calculated from water stage
differences and a known volume-stage relationship. This recorder
was installed in May 1968 and removed in October 1968.
At Sunset Bay State Park, a totalizing flow meter at a pump
station preceding the treatment plant was read daily during the
survey period at the time of sample collection.
*Leopold-Stevens Type F Recorder. Use of product and company
names is for identification only and does not constitute endorsement
by the U. S. Department of the Interior or the Federal Water Pollution
Control Administration.
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14
Sampling
Two surveys were made at Timber! ine Lodge from January 20-29,
1968 and May 10-13, 1968. Samples were collected from the
influent sewer, aeration basins, and clarified effluent.
Grab samples of the raw wastewater were collected every hour
using an automatic sampler and then composited proportional to
flow.
Grab samples of each aeration basin were collected once per
day and mixed in equal proportions.
The clarified effluent sample was collected using an automatic
sampler constructed at the Pacific Northwest Water Lab. This
device consisted of a small pump operating continuously. The flow
passed through a double chambered funnel with a solenoid valve
that operated off a recycle timer. Every minute for five seconds,
the timer activated the solenoid which directed the flow into an
iced sampling container. Figure 2 illustrates this sampling
apparatus.
Three surveys were made at Crystal Mountain from February 11-19,
March 8-12, and April 26-29, 1968. During the March 8-12 survey,
the National Alpine Ski Championship was being held at the Crystal
Mountain area. Composite samples were collected from the raw
wastewater and clarifier effluent and a daily grab sample was
collected from the aeration tank. The method of sampling was the
same as that used in the Timberline Lodge surveys.
Single surveys were made at Bui lards Beach and Sunset Bay
State Parks both during the period from June 14-20, 1968. Samples
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Sampling Unit
Pump and
Sampling Timer'
Unit Timer
110 volt Plug
Sample Container—I
Drain
• Pump
FIGURE 2. SAMPLING UNIT
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16
were collected daily from the raw wastewater, aeration basin and
clarified effluent. The raw wastewater sample at both areas was
'collected and"composited automatically using-the device shown in
Figure 2. This sampler is similar to the pump sampler described
previously, except that the unit can be battery operated. The
unit was programmed to collect sample volumes in proportion to
the average flow distribution at each area. The aeration tank
sample was a grab sample collected once per day, and the final
clarifier sample was collected in the same manner as described
previously for the Timberline Lodge surveys.
All samples were iced during collection and while in transit
to the Pacific Northwest Water Laboratory in Corvallis, Oregon.
Samples for COD analysis were preserved with concentrated sulfuric
acid and samples for nitrogen and phosphorous analysis were
preserved with mercuric chloride.
Unpreserved samples were used for all other analyses. Analysis
of unpreserved samples for BODc occurred within a 24-hour period.
In order to check the change in BOD5 during sample shipment, a grab
sample was collected on January 12 from the Timberline Lodge raw
sewage, stored at 5°C, and then analyzed for BOD5 after four
hours and 28 hours. There was less than 10 percent difference in
the values which is within the accuracy of the BOD5 test.
Analysis
All laboratory analyses, with the exception of centrifuged
BOD5 and COD, TPO. and OPO., were performed in accordance with the
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17
2/
12th Edition of Standard Methods-. Field analyses were made for
temperature, D.O., pH, and percent solids in the aeration basin.
D.O. and pH were measured using battery-operated probes. Percent
solids was measured in accordance with Standard Methods.
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PLANT DESCRIPTIONS
Each of the systems is described below with pertinent
details given regarding the types and sizes of facilities
available and the type of area served. Figure 3 also illustrates
the flow diagram of each system.
Crystal Mountain
The treatment system at this area presently serves only a
portion of the total facilities which includes a day lodge,
administration building and two overnight lodges.
Treatment consists of screening, comminution, complete mix,
biological aeration, clarification with return sludge facilities
and final disposal to a subsurface drain field. Aeration is
provided by a mechanical surface aerator on a timed basis. Table 1
gives pertinent details regarding volumes and capacities for this
system.
TABLE 1
DETAILS OF CRYSTAL MOUNTAIN TREATMENT SYSTEM
Facility Description
AERATION TANK Square concrete construction
Dimension 21' x 21' x 11 1/4'
Volume 37,000 gallons
Aerator 10 Hp mechanical aerator
CLARIFIER Circular radical flow
Surface area 201 ft.2
Volume 14,850 gallons
Overflow weir length 47 ft.
SLUDGE RETURN Air lift pump
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Screening
and
Comminution
Aeration Basin
Final Clarifier
Raw Sewage
lOhp. Aerator
Return Sludge
Drain
Field
CRYSTAL MOUNTAIN PLANT
Screening
and
Comminution
Raw Sewage
Aeration Basin
a
5hp
'Aerator
O
5hp
'Aerator
Aeration Basin
Gas Chlorinator
o
Return Sludge
Chlorine
Contact
Tank
To
Stream
TIMBERLINE LODGE PLANT
Hypochlorite
Screening
Raw Sewage
Aeration Basin
«-Pipe Diffuser
Chlorine
Contact
Tank
Gravity Return
Sludge
BULLARDS BEACH AND SUNSET BAY PLANTS
FIGURE 3. TREATMENT PLANT FLOW DIAGRAMS
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21
Timberline Lodge
The treatment system at this area serves all facilities at
the ski area which essentially includes only a combined overnight-
day lodge with a restaurant and lounge.
The treatment system consists of screening and comminuting the
raw sewage, secondary biological treatment in two 30,000 gallon
aeration tanks each with a 5 Hp mechanical surface aerator, secondary
clarification, chlorination of the final effluent with a gas
chlorinator and baffled chlorine contact chamber. Like Crystal
Mountain, the aerators at this plant are on a timed basis. Table 2
gives pertinent details of this system.
TABLE 2
DETAILS OF TIMBERLINE LODGE SYSTEM
Facility
Description
AERATION TANK
Volume
Aeration
CLARIFIER
Volume
Surface Area
Overflow weir length
Chlorine contact chamber
Volume
2 - 19' x 19' x 12' concrete tanks
30,000 gallon/tank
2 - 5 Hp mechanical aerators
Rectangular concrete basin
19' x 6' x 12'
11,050 gallons
114 ft.
12 ft.
Rectangular basin with over-
under redwood baffles
2,175 gallons
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22
Bui lards Beach
The treatment system at this area serves the overnight
campground with 128 camp sites and a day-use area with a single
bathhouse.
Treatment is provided by a small extended aeration package
plant with a capacity of 11,000 gallons per day (gpd). The
package plant provides screening, aeration with diffused aerators,
clarification with sludge return by gravity and chlorination prior
to discharge to the Coquille River.
Table 3 gives pertinent details of the system.
TABLE 3
DETAILS OF BULLARDS BEACH SYSTEM
Facility 'Description
AERATION
Volume 11,000 gallons
Aerators Pipe diffusors with air
compressors
CLARIFICATION
Volume 920 gallons
Surface area 40 ft.2
Sunset Bay
The treatment system at this area receives the septic tank
effluent from an overnight campground with 137 camp sites, and a
large day-use area.
The treatment plant is also a packaged extended aeration system
with 17,000 gpd capacity of the same type as that at Bui lards Beach.
After chlorination, the effluent is discharged to the Pacific Ocean.
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23
Pertinent details are given in Table 4.
TABLE 4
DETAILS OF SUNSET BAY SYSTEM
Facility Description
AERATION TANK
Volume 17,000 gallons
Aerator Diffused aerators
CLARIFIER
Volume 1,430 gallons
Surface area 60 ft.
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RESULTS
Pertinent analytical and field data is summarized for each
area in Table 5 and complete data is provided in the Appendix.
Figure 4 illustrates the variation in aeration detention time
and organic loading at each of the four plants studied.,
Hydraulic Loadings
Data on the hydraulic loading is presented in Table 6 in
terms of average daily theoretical detention time in the aeration
basin and the hydraulic surface loading on the final clarifiers.
For the two ski areas, the aeration detention time was
highly variable and on an average basis, considerably greater
than normally found in extended aeration treatment. At Timber!ine
Lodge, the detention time varied from 3.8 to 15.8 days with an
average of 8.9 days for the two survey periods. The average
detention time for the weekdays monitored (weekdays are considered
as 9:00 am Tuesday through 9:00 am Friday) was approximately 11.5
days while the average for weekends (9:00 am Saturday through
9:00 am Monday)* was 6.0 days. The most severe shock load in
terms of daily change was from 10.4 to 3.8 days or approximately
a three-fold increase in flow. At Crystal Mountain, the detention
time varied from 0.8 to 14.3 days with an average of 3.6 days
for the three survey periods. The average for the weekdays
monitored was 6.2 days and 2.8 days for the weekends.
*Monday is considered as part of the weekend because flows were
measured from 9:00 am to 9:00 am and the flow measured Monday
would include flows from Sunday.
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TABLE 5
ANALYTICAL DATA SUMMARY
BOD Mg/1
Period
Timberline
Lodge
1/21-29
Timberline
Lodge
5/10-13
Crystal
Mountain
2/11-19
Crystal
Mountain
3/8-12
Crystal
Mountain
4/26-29
Bui lards
Beach
6/11-20
Sunset
Bay
6/14-20
Location
Inf
Aer
Eff
Inf
Aer
Eff
Inf
Aer
Eff
Inf
Aer
Eff
Inf
Aer
Eff
Inf
Aer
Eff
Inf
Aer
Eff
Total
485
—
70
320
—
47
400
1730
135
228
2550
. 80
393
1211
51
79
--
30
92
--
22
Filtered
250
—
13
.._
—
16
__.
32.2
18.6
64.2
26.6
__
32.8
18.0
_ _
--
10.4
_ _
--
64
COD
Total
833
—
230
580
—
172
953
4128
216
470
3850
206
650
5450
195
220
--
53
188
--
41
Mg/1
Fi 1 tered
380
—
67
__
—
74
__
218
89
__
—
77
__
236
53
__
25
« _
--
19
SS
Mg/1
470
2150
145
171
2025
86
405
3599
222
282
3390
121
395
4260
120
75
997
25
59
717
20
VSS
Mg/1
410
1885
125
149
1865
75
367
3154
191
246
2990
97
385
3950
108
__
--
— _
--
—
TP04
Mg/1
13.2
--
10.2
11.4
—
10.3
16.6
—
11.5
7.9
--
7.1
11.3
_-
10.0
5.2
2.6
8.3
6.8
TKN NH3 I>
Mg/1 Mg/1
71.10 43.5
__
26.9 12.5
44.1 13.6
—
15.6 2.9
91.2 29.1
262 47.0
59 31.9
54.1 11.4
153 21.0
32.3 19.7
86.3 15.4
226 26.3
34.5 26.0
46.32 39
14.87 12.74
73.73 65.8
24.77 27.46
Mg/1
0.30
--
27.76
0.33
--
10.2
0.35
30.60
28.40
0.18
10.10
10.90
0.35
45.20
45.60
0.03
22.19
0.03
38.74
Alk
Mg/1
247
75
61
133
80
13
320
170
93
212
133
35
252
120
n
195
43
3
282
54
4
PH
7.2
5.7
5.3
6.2
5.7
5.2
6.4
6.7
6.7
6.8
6.6
6.6
6.8
6.2
5.7
7.1
6.1
5.4
7.3
6.5
5.3
Temp
°C SVI
—
10.5
__ __
10.1 380
--
_ _ __
3.6 146
—
__ __
6.0 248
—
__
5.0 372
— _
15.7 67
--
__
13.4 48
--
Average
flow.gpd
8,720
7,625
9,250
23,100
7,000
7,900
12,870
-------
14
12
IO
8
o
o
0.3O
I
to
5
2 020
o
o
0)
-«> 0.15
O.IO
0.09
0 i
U1MMU
TIMBERLINE LODGE
CRYSTAL MOUNTAIN
r i SMTWT
BOLLARDS BCH SUNSET BAY
FIGURE 4. HYDRAULIC AND ORGANIC LOADINGS
-------
TABLE 6
SUMMARY OF HYDRAULIC AND ORGANIC LOADINGS
AREA
Timber! ine Crystal Bui lards Beach Sunset Bay
Loading Average Range Average Range Average Range Average Range
Detention
Time, Days 8.9 3.8-15.8 3.6 0.8-14.3 1.3 1.2-1.6 1.3 1.2-1.6
Clarifier Sur-
face Loading,
gpd/ft2 61 33-139 65 12-234 210 -- 210
Ib BOD/
Ib MLVSS-day 0.031 0.004- 0.048 0.002-0.136 0.056 0.025-0.116 0.065 0.055-0.093
0.062
Ib BOD/
1000 ftVday 3.0 — 6.5 — 4.2 — 3.8
Ratio of average
weekend loading
to average week-
day loading 1.3 1.5-6.0 3.2 2.0-17.0
-------
29
The hydraulic loading on the final clarifiers at the two
ski areas was equally as variable as the aeration detention
time. At Timberline Lodge, the average daily rate varied from
33 to 139 gpd/ft2 and at Crystal Mountain from 12 to 234 gpd/ft2
These values are not unusually high on the basis of normal
design rates of 400-600 gpd/ft2, but it should be remembered that
they are average daily rates, whereas, design is on the basis of
peak rates. On the basis of peak flows, which are on the order of
ten times the average daily flow rate—, the maximum surface
loadings would be 1,390 gpd/ft2 for Timberline Lodge and 2,340
gpd/ft2 for Crystal Mountain, both of which exceed design values.
The hydraulic loadings found at both the summer parks,
Sunset Bay and Bullards Beach, were quite constant during all
days of the survey period with a total range in aeration detention
times from 1.2 to 1.6 days and an average surface loading on the
final clarifiers of approximately 210 gpd/ft2. The reason for
the constant loading at Bullards Beach is attributed primarily
to an extremely high rate of infiltration. It is estimated that
there was over 5,000 gpd of infiltration to the system during the
survey period which accounts for 60-70 percent of the entire
wastewater volume. This high rate tends to dampen any fluctuations
from wastewater contributed through actual camper use. The
constant flow at Sunset Bay is attributed to detention time in
the collection system prior to being pumped to the plant and
infiltration. Each rest station at this area has a septic tank
-------
30
that precedes the actual wastewater discharge to the treatment
plant. The combination of long collection system detention time
and infiltration tend to dampen any hydraulic loading fluctuations
Organic Loadings
The organic loading on all four systems studied was quite
low for extended aeration biological systems. Normally, an F
value of 0.1 to 0.2 Ib BOD5/lb MLVSS-day is used in design. In
terms of volumetric capacity, this would be on the order of
15-20 Ib BOD5/1,000 ft3 of aeration capacity. At the two ski
areas, the average organic loadings were quite low compared to
the normally ,used design values and were highly variable on a
day to day basis. Timberline Lodge loadings were less variable
than those at Crystal Mountain due to the more consistent usage
at this area. At Timberline Lodge, the average organic loading,
F, was 0.031 with a range from 0.004 to 0.062. It can be noted
that even the highest loading found was well below the average
design value of 0.10. The difference between weekend and weekday
loadings was not as great as might be expected from a ski area
with a ratio of 1.3 for the average weekend to average weekday
loading. At Crystal Mountain, the organic loading, F, averaged
0.048 with a range from 0.002 to 0.136; There was considerable
variation from weekday to weekend loadings as indicated by the
average ratio of 3.2 with a value as high as 17 noted on one
occasion. In terms of volumetric loadings, the average values
were 3.0 and 6.5 Ib BOD5/1,000 ft3 for Timberline Lodge and
Crystal Mountain, respectively.
-------
31
The organic loading at Billiards Beach and Sunset Bay were
by comparison to the two ski areas quite consistent with respective
average ratios of 0.056 and 0.065 and ranges from 0.025 to 0.116
and 0.055 to 0.093. There was little difference noted between
weekdays and weekends. The average Ib BOD /l,000 ft3 ratio was
3
4.2 for Bullards Beach and slightly lower at 3.8 for Sunset Bay.
Like the two ski area systems, both Bullards Beach and Sunset Bay
are underloaded on an average basis.
System Efficiencies
The efficiency of all four plants studied on the basis of
BOD(-> COD and SS was quite variable as shown by Table 7 and
illustrated by Figure 5.
At Timberline Lodge, the average total BODs removal
efficiency was 84 percent with a range from 55 to 97 percent.
The average COD removal efficiency was 71 percent and the average
suspended solids removal was 59 percent with a range from 0 to
96 percent.
The Crystal Mountain system generally performed similar to
the Timberline system with perhaps a little more variability.
The average total BODg, COD and SS removals were 80, 70, and 57
percent, respectively. A high degree of variability, though, is
indicated by the fact that the removal of all three parameters
varied from actually less than 0 percent to over 90 percent.
-------
TABLE 7
SUMMARY OF TREATMENT PLANT REMOVAL EFFICIENCIES
Parameter
% Total BOD5
% Centrifuged
BOD5*
% Total COD
% Centrifuged
COD*
% ss
Timber line
Average
84
98
71.0
90.0
59
*Based on comparison of total
Lodge
Kange
55-97
92-99
36-92
75-94
0-96
influent
Crystal Mountain
Average
80
94
70
89
57
analysis to
Range
0-94
81-97
0-90
76-96
0-95
centrifuged
Bui lards Beach
Average
62
87
74
86
67
effluent analysis
Range
34-79
84-93
56-84
82-91
0-85
Sunset
Average
73
92
75
90
66
Bay
Range
42-89
89-93
60-87
88-92
0-89
-------
i
o"
o
at
IOO
8O
60
4O
2O
|
o
o
o
IOO
80
60
40
20
O
TOO
600
4OO
SOO
E
co
3 2OO
IOO
O
I
PSSMTWTPSS fSSM FSSM
CRYSTAL MOUNTAIN
SMTWTFISM rtSM
TIMBERLINE LODOE
FSS'MIWT FSSMTWT
BULLARDS BCH SUNSET BAY
FIGURE 5.
PERCENT
AND EFFLUENT SS
B009 AND COO REMOVALS
-------
34
Builards Beach system had an average 800$ removal of 62
percent, a COD removal of 74 percent, and SS removal of 67 percent.
The Sunset Bay system averaged 73 percent 8005 removal, 75 percent
COD removal and 66 percent SS removal. The reason for the higher
COD efficiency relative to BODs is attributed to nitrification
in the BODs test on the effluent samples. Table 10 is a graph
of the effluent 8005 versus COD, and illustrates this point by
having a positive BODs value when the COD is zero.
Also given in Table 7 is the percent efficiency for BODs
and COD removal based on centrifuged effluent samples. These
data indicate that the BODs and COD efficiency of the systems
could be improved from 10-20 percent through more efficient
removal of effluent suspended solids.
Figure 6 shows the COD loading versus percent COD- removed
on the basis of total effluent analysis and centrifuged effluent
analysis. This figure also indicates the considerable effect
of suspended solids carryover in the final effluent which becomes
of greater significance as the loading decreases. It can be
seen that if the loading decreases from 0.2 to 0.1 Ib COD/1b
MLSS-day, the efficiency based on total sample analysis decreases
from 78 percent to 75 percent, but the efficiency based on
centrifuged samples increases from 91 percent to 93 percent.
-------
Legend
Timb«rlin«
Crystal Mm.
Billiards Beach
Sunset Bay
O
*
D
A
lOOr
o 90
o
0>
or
Q 80
O
u
a>
« 70
a»
0.
60
50
0.10 0.20
COO Organic Loading Ib COO/lb MLVSS-day
0.30
FIGURE 6-
COD ORGANIC LOADING VS COD REMOVAL
EFFICIENCY FOR TOTAL 8 CENTRIFUGED
EFFLUENT SAMPLES
-------
36
Figure 7 illustrates the relationship between sludge
volume index (SVI), effluent suspended solids, and organic
loading. Over the range of values encountered in these surveys,
the effluent suspended solids was found to vary directly with
SVI and inversely with organic loading. For example, if the
organic loading was 0.1, the SVI would be approximately 130
and the effluent SS would be approximately 90 mg/1. If the organic
loading was increased to 0.2, the SVI would decrease to 40 and
the effluent SS would decrease to 20 mg/1.
It should be noted, though, that Figure 7 is based on an
average of data obtained in each survey; and if the individual
data points were plotted, there would be considerable scatter to
the Timberline and Crystal data. The cause of this scatter is
attributed to a floating sludge problem which was observed on
several occasions at both plants. The problem was not noted at
either Bui lards Beach or Sunset Bay.
Table 8 gives data on the BOD5 and COD values of the MLVSS
for the Crystal Mountain system during the period of February 10-19
and April 26-29. During the first period, the data indicated
average ratios of 0.54 mg BOD5/mg VSS and 1.25 mg COD/mg VSS.
During the second period, the BOD,-/VSS ratio had decreased to
0.3, but the COD/VSS ratio remained constant at 1.30. Corresponding
sludge ages for these periods were 122 days and 190 days,
respectively. The theoretical ratio for COD/VSS is approximately
1.4 and agrees quite closely with the data in Table 8. However,
the ratio for BODc/VSS, which was expected to be on the order of
-------
300
200
X
O)
•o
Q>
E
100
O
100
Effluent Suspended Solids mg/l
200
400
300
X
a>
•o
200
a»
o>
TJ
100
Legend
Timberline o
Crystal *
Bullards 0
Sunset Bay A
O.I
0.2 0.3
Ib COD/lb MLVSS-day
0.4
0.5
FIGURE 7. SLUDGE VOLUME INDEX (SVI) VS
LOADING AND EFFLUENT SS
-------
38
TABLE 8
RATIO OF BOD5/VSS AND COD/VSS FOR THE CRYSTAL
MOUNTAIN MLVSS DURING SURVEYS OF 2/10-19 and 4/26-29
Date
2/10
11
12
13
14
15
16
17
18
19
Average (2/10-19)
4/26
27
28
29
BOD5/VSS
0.59
0.49
0.51
0.48
0.48
0.42
-
0.65
0.60
0.63
0.54
0.36
0.25
0.31
0.26
COD/VSS
1.28
1.08
1.27
1.16
1.30
1.02
1.51
1.53
1.10
1.28
1.25
1.38
1.42
1.20
1.21
Average (4/26-29) 0.30 1.30
-------
39
0.2-0.3 at the high sludge ages encountered, was considerably
greater than this during the first period, but agrees fairly
well during the second period.
The higher ratio during the earlier survey may be attributed
to nitrification in the BODg analysis and the fact that the
system had been operating only for 3-4 weeks prior to the survey
and perhaps only 5-10 days at a significant loading level. This
would indicate, then, a true sludge age considerably lower than
the 122 days calculated on the basis of Ib solids under aeration/lb
solids wasted/day.
Alkalinity and pH
Figure 8 illustrates the variation with day of week in
influent and effluent alkalinity and pH for each of the four
plants studied.
At both Timberline Lodge and Crystal Mountain, there was
considerable variation in the influent alkalinity and pH. On
weekdays the alkalinity dropped to approximately 1/2 to 1/3
the weekend value and the pH dropped accordingly.
In the effluent, the Timberline system showed an average
decrease in alkalinity of 153 mg/1 or approximately 81 percent.
There was a corresponding decrease in average pH from 6.7 to
5.2 with a value as low as 3.9 in the final effluent. The
Crystal Mountain system had an average decrease in alkalinity of
215 mg/1 or over 82 percent. The average decrease in pH through
the system was not as severe as at Timberline being from 6.7 to
-------
LEGEND
Jnflutnt—©—
Final Effluent—A—
SM TWT PSSM P8SM
TIMBERLINE LODGE
PSSMTWTPSS FSSM fSSM
CRYSTAL MOUNTAIN
FSSMTWT
BULLARDS BCH SUNSET IAY
FIGURE 8, ALKALINITY AND pH VARIATIONS
-------
41
6.3. The low pH value at Crystal was 5.0 which occurred during
the third survey.
At Bullards Beach and Sunset Bay, the influent alkalinity
and pH increased approximately 50 mg/1 for alkalinity and 0.5
pH units. As shown by Figure 6, the alkalinity in the effluent
was less than 10 mg/1 for all days except one when it increased to
approximately 30 mg/1. For Bullards Beach, this represents an
average decrease in alkalinity of 192 mg/1 or over 98 percent,
and for Sunset Bay a decrease of 278 mg/1 or nearly 99 percent.
As could be expected with this large decrease in alkalinity, the
average pH decreased significantly in the effluent from 7.1 to
5.4 for Bullards Beach and 7.3 to 5.3 for Sunset Bay. It is of
interest to note that for Sunset Bay the major reduction in pH
occurred in the final clarifier rather than in the aeration basin
as was the case for the other units studied.
Aeration Sludge Analysis
During the first surveys at Timberline Lodge (January 21-29)
and Crystal Mountain (February 11-19), the activated sludge in
the aeration basins was subjected to a qualitative microscopic
analysis.
At Timberline Lodge, the analysis indicated a protozoan
population with free swimming ciliates, and a few stalked ciliates.
There were very few rotifers identified, a large number
of filamentous fungi and a few green algae. The floe was described
as being highly dispersed.
-------
42
At Crystal Mountain, there was a good protozoan population
primarily of stalked ciliates. No free swimming ciliates or
rotifers were found. There was a considerable amount of fungi
present which was identified as Geotrichum condidum. The floe
was described as being highly dispersed.
Nitrification
Figure 9 illustrates the percent nitrification, measured as
quantity of (NO., + NC^) in the effluent divided by quantity
of total nitrogen in the influent, versus organic loading (Ib BOD-/
Ib MLVSS-day) for the four plants studied. This figure also
illustrates a normal curve at approximately 20°C as reported by
3/
Eckenfelder—. Nitrification at all four plants is less than 20
percent at a loading of 0.10 Ib BOD5/lb MLVSS-day. Compared to
essentially 100 percent, nitrification under normal pH and
temperature conditions at this loading, it can be noted that
nitrification at the areas studied is depressed considerably.
-------
o" 60
Lro
50
£ 30
LEGEND
Timberline
Crystol Mtn.
Bui lords Bch.
Sunset Bay
•After Eckenfelder (3)
' O
0 O.I 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
Organic Loading, Ib BODg/MLVSS-day
I.I
1.2
FIGURE 9. ORGANIC LOADING vs % NITRIFICATION
-------
DISCUSSION
This section of the report will first discuss organic removal
kinetics, biological synthesis and respiration rates, nitrification
and denitrification, loading effects and how these relationships
apply to the systems studied.
System Organics Removal
The total efficiency of a treatment system in removing
organic matter expressed as COD or BOD,-must consider two forms
of organic matter in the effluent: (1) the soluble portion, and
(2) the portion contributed by organic solids which from an
activated sludge process would be principally biological cells.
In terms of COD, the total removal efficiency can be
expressed by the relationship:
E = L°
where
x 100
E = total COD removal efficiency
L' = total influent COD
LE = total effluent COD
where L; = soluble effluent COD
LS = effluent COD due to solids
Soluble COD
The rate of soluble COD removal in a biological treatment
system is related to the quantity of active microorganisms present,
-------
46
the length of time the organisms are in contact with the food
source and the quantity of COD present—/ This concept can be
expressed mathematically as:
^ = KSL (1)
dt a
where ^ = rate of change of COD with time
K1 = COD removal rate, time"
Sg = average concentration of active micro-
organisms under aeration as measured by
volatile suspended solids, mass/volume
L = COD remaining in reactor, mass/volume
By making a material balance around a completely mixed biological
treatment system, the following relationship can be developed—*—*—.
L°s ' L° = K'i; or M' = K'L^ (2)
3
M1 = L^ - Le/Sat, Time"1
L' = influent organic matter, mass/volume
Lg = soluble effluent organic matter,
mass/volume
t = aeration detention time,
Equation 2 passes through the origin which indicates that
when L' = 0, M' =0 or vice versa. However, this is seldom the case
because of the organic matter that is associated with SS and a
portion which is nonbiodegradable. Therefore, equation 2 is normally
seen as M1 = KV ± 2- (3)
where 2- is the combination of positive removal due to SS
settling out or negative removal due to nondegradable organic matter.
-------
47
Equation 3 is of the form, y = ax-b which plots as a straight
line on cartesian coordinates with a slope equal to (a) and inter-
cept equal to (b). Therefore, by plotting M' versus L1 on
cartesian coordinates, a straight line should result with a slope
equal to the substrate removal rate (K1) and an intercept equal to
£. However, since (K1) is temperature dependent and all data obtained
in these surveys are at different temperatures, they should be adjusted
before they can be compared on an equal basis. This can be done
using the van't Hoff Arrhenious temperature relationship:
K - K n1'20
KT ~ K20° (4)
where KT = reaction rate at temperature T
Kp0 = reaction, rate at 20°C
T = temperature
0 = temperature coefficient
Values have been reported for 0 in the literature ranging from
3 4 5 6/
1.0 to 1.08 ' ' * 'depending on the type of treatment system
being used. A typical value for activated sludge treatment of
domestic waste is 1.038 as reported by Pohl— and will be used in
this report.
Figure 10 represents Ib COD removed per Ib MLVSS-day, M1,
converted to 20°C, for the data obtained from the four plants
studied in this report, data for properly buffered activated sludge
systems obtained in two surveys of the Camp Angel 1 Job Corps Center
plant during August 1967 and January 1968, and data from Pomona,
California, reported by Jenkins and Garrison—( It will be noted
that two separate curves can be drawn for these data.
-------
LEGEND
Timberline
Crystal Mtn.
Bullards Bch.
Sunset Bay
Camp Angell
Pomona,Calif, after
Garrison 8 Jenkins (7)
a
A
0.8
0.7
J)
2 0.5
51 0.4
o
E
a: Q g
o
o
o
£ 0.2
"s
O.I
M'= 0.017 Le'-0.078 (R = 0.986)
M'=0.0022Le'-0.072 (R = 0.72I)
50
Le' Filtered Effluent COD mg/l
IOO
FIGURE 10. FILTERED EFFLUENT COD vs COD
REMOVAL RATE
-------
49
Linear regression analysis of the data indicate a 20°C
COD removal rate of 0.017/day for the plants at Sunset Bay,
Pomona, California, and Camp Angell, and 0.0022/day for the
Timberline Lodge, Crystal Mountain, and Bullards Beach plants.
The correlation coefficients of 0.986 and 0.721 for the two
curves, respectively, appear to verify the linear model used
to describe the reaction rate kinetics. It will be noted that
the curves have a negative intercept which can be interpreted
to mean that there is a portion of the substrate that is
nonremovable regardless of loading level. This is not unusual
when using COD as a measure of organic substrate because there
is normally a portion of the COD which is nonbiodegradable and,
therefore, not removable in a biological system. If the intercept
were positive, this would indicate significant contribution of
COD due to SS.
To investigate whether or not the removal rate was temperature
dependent as previously assumed, regression analyses were performed
on the Timberline, Crystal, and Bullards data before and after
temperature adjustments. The correlation coefficient was improved
from 0.674 to 0.721 which, although not a major improvement,
still appears to confirm the temperature dependency of the
removal rate coefficient.
The removal rate of 0.017/day for the Camp Angell, Pomona,
and Sunset Bay data when converted to a BOD,- basis is quite
comparable to data reported in the literature that range from
0.02 to 0.04/day.
-------
50
On the other hand, the rate of 0.0022/day obtained from the
Timberline, Crystal, and Billiards data is extremely low and is
attributed principally to low and variable aeration pH and the
fact that the raw waste is unsettled prior to treatment3*10'11/.
Of these factors, variable aeration pH is perhaps the most
significant, particularly at the lower temperatures encountered
at Crystal and Timberline.
Eckenfeldei—' reports that a rapid change in pH will decrease
the respiratory activity of biological organisms by as much as 75
percent; and this effect is compounded at low temperatures. While
low pH in the aeration basins will reduce the organic removal rate
significantly for a normal bacterial population, a fungi dominated
population will develop that operates quite efficiently at pH levels
as low as 2.5-^- . Therefore, if the pH level does drop, but remains
steady, little loss in organic removal efficiency should be noted
when the system reaches steady state conditions. This was indicated
by the data obtained at Sunset Bay, which operated at a low, but
rather steady pH level of 5.1 to 5.5, and had a normal organic
removal rate comparable to those reported in the literature.
The second factor that would tend to reduce the removal rate
is the fact that the waste at Timberline, Crystal, and Bullards is
unsettled with approximately 30 percent of the total organic load
in the form of suspended solids. It is reasoned that the portion
of organic matter in the form of solids would be degraded at a
lower rate than the soluble portions. Since most of the values
-------
reported in the literature are for settled or principally soluble
substrates, it seems reasonable to expect a rate somewhat lower
for systems without primary settling. As mentioned before, though,
this is not considered a major factor.
That portion of the effluent COD due to solids, LS, can be
expressed by the relationship XS , where X is the ratio of COD to
VSS and SQ is effluent VSS. In terms of COD, the ratio X should
be relatively constant for a given substrate with a theoretical
value of 1.42 for a pure biological solid. However, there is
usually a portion of nondegradable VSS in the aeration basin which
lowers the ratio. In surveys at Crystal Mountain, this ratio varied
from 1.25 to 1.30.
Sludge Synthesis and Endogenous Respiration
Since the quantity of new cells produced must eventually be
disposed either in the effluent or through separate wasting, it
is extremely important to have an estimate of the actual
quantity produced in order to design sludge wasting and holding
facilities. This is also important from an economic standpoint
because in many installations sludge handling and disposal facilities
may amount to as much as 50 percent or more of the total plant
costs (capital plus operation and maintenance).
Incoming organic material, expressed as COD or BOD5, is
utilized by the microbiological population in a biological treatment
system for new cell-growth and metabolic energy. This can be
expressed as:
Organic Matter + bacteria + 02+ new bacterial cells +
Stable end products (C02, N03, H20)
-------
52
It can be further expressed by the following relationship if a
materials balance is made around a biological reactor at steady
state conditions,
V = aM - b(QT~20) (5)
where T' = Sludge age or Ib MLVSS/lb VSS wasted
per day
a = Fraction of COD or BOD,- removed to produce
new VSS or Ib VSS prodticed/lb COD or BOD,.
removed per day
T-20 T-20
0 = Temperature correction factor equal to 1.038
T = Temperature, °C
b = Fraction of VSS destroyed through self-
respiration or endogenous respiration, Ib VSS
destroyed/1 b MLVSS per day
Monod—'has defined the growth rate (a) of pure cultures of
microorganisms on defined substrates to be related to the concen-
tration of a growth limiting substrate. However, it has been
shown ' * 'that a first order approximation of the Monod equation—',
i.e., where the sludge growth rate is directly proportional to
substrate concentration, can be used to estimate the growth rate
in activated sludge treatment of domestic wastewater.
From inspection of a normal activated sludge growth curve,
as shown in Figure 11, it can be seen that the endogenous decay
rate can be described by an exponential function of sludge age
-------
c
o
u
c
o
o
O)
o
Sludge Age
FIGURE II- SLUDGE GROWTH CURVE
-------
54
or that
which can be reduced to the form
(7)
bT - be-*T (8)
where b- = endogenous rate at sludge age T, days
b = maximum endogenous rate
$ = rate die-off constant
by integration from the limts b = 0 at T = °° and b = b at T = 0.
rnaX
This assumes that the endogenous rate b is a maximum at a sludge
age of 0 days which is not exactly true because of the growth
period of up to one day, but should be sufficiently accurate for
this analysis and most applications. This is particularly so
since the growth period of one day is small compared to the die-
•
off period.
Equation 5 then can be written as
VT, = aM - b e~*T' O-0381"20) O)
max
Equation 9 has been curve-fitted to the data obtained in
surveys at the four recreation areas as well as data from Pomona,
California— and the constants a, b__ , and $ evaluated. This was
max
done on the basis of both BOD,- and COD.
On the basis of BOD5 data, the sludge synthesis fraction, a,
equalled 0.54, b ,„ was equal to 0.052, and $ was equal to 0.02.
max
The resulting equation with these constants is shown together with
the survey data in Figure 12. It can be seen that the relationship
describes the data quite well.
-------
Timbtrlin*
Crystal Mtn.
Bullard* Beh
Surutt Bay
O
*
a
0.10
a»
o»
a»
o»
0.05
-= 0.54M-0.052e-°-02T
0 0.05 0.100
Organic Loading (M) Ib B000 Removed/lb MLVSS-day
FIGURE 12- SLUDGE AGE VS BOD5 ORGANIC LOADING
-------
56
On the basis of COD data, including Pomona, California data,
the sludge synthesis fraction was equal to 0.33, and both bmav
IllaX
and $ were the same as for the BOD5 relationship. The resulting
equation and the data are illustrated in Figure 13 and again, it
can be seen that there is good agreement between actual data
and predicted data.
The sludge synthesis fraction, a, on the basis of BOD5 data
agrees quite well with values reported in the literature. Both
the National Sanitation Foundation^/ and McCarty and Broderson^7
reported values of 0.53. The value of 0.33 calculated on the
basis of COD data also agrees quite well with the value reported
by Jenkins— and on the basis of BOD5/COD relationship of approximately
0.58 (See .. Table 9, appendix) appears reasonable. The maximum
endogenous rate (t>max) of 0.052 is quite low compared to the
value of 0.18 used by Eckenfelder—', National Science Foundation—
187
and McCarty and Broderson—, but agrees closely with the value
reported by Jenkins-'of 0.04. Since most of the work supporting
the higher value of 0.18 was done on a laboratory bench scale basis,
perhaps the difference between the two values is due to scale
effects from the laboratory to the field. At any rate, it is felt
that the values reported here and by Jenkins— are more reliable
since they are based on actual full scale systems
While the predicted relationship between sludge age and
organic removal rate given by equation 9 appears to describe the
actual process satisfactorily, it should be noted that the equation
-------
Legend
0.25
0.20
0.15
a>
o>
< O.IO
a>
o>
0.05
A
Timber-line
Cryttol Mtn.
Bullard* Bch.
Sunset Boy
Q
A
l/T=o.33rvr-o.o52e~a°2T
0.5
COO Organic Loading M'
1.0
FIGURE 13- SLUDGE AGE VS COD ORGANIC LOADING
-------
58
does not distinguish any possible pH effects from extended sludge
age effects on the endogenous rate. However, it is felt that
the equation should be satisfactory in most instances of recreation
waste treatment for the reason that low variable pH appears to be
a characteristic of systems that are loaded below an average of
0.10 Ib COD/lb MLVSS-day and have extreme loading variations
from day to day. Therefore, the extended sludge age, which generally
in a completely mixed system, also means low loadings and low pH
appear to be related.
Nitrification - Denitrification
This aspect of the operation of an extended aeration
biological treatment system is extremely important in the control
of the efficiency of the system. Nitrification can have a
significant effect on pH which in turn affect the organic removal
rate and solids removal efficiency. In a study of 14 small, extended
aeration systems in Massachusetts, the Massachusetts Public Health
207
Department— concluded that nitrification will cause a decrease
in pH in soft water areas and create an environment favorable for
filamentous microorganisms. Findings from this study support
essentially the same conclusion.
The oxidation of organic nitrogen to NO- requires stoichiometrically
one mole of alkalinity per mole of organic nitrogen converted. This
-------
59
is shown by the following set of reactions:
Org N + bacteria — »• NHg
NH3 + H20 ^ NH* + OH"
OH" + C02 ^ HC03
NH~ + 202 ^ 2H+ + NO" + H20
2H+ + 2HCO" ^> H2C03
H2C03 T± C02 + H2°
Adding these reactions together gives the following net reaction
Org N + HCOg + 202 -+ N0~ + H20
Stated another way, the oxidation of 1 Ib of Org N as N
requires 3.6 Ib of alkalinity as CaCO-.
The oxidation of NH., which in normal domestic sewage accounts
for approximately 90% of the organic nitrogen due to the conversion
in the sewer from organic nitrogen to NH. is given, by the net
reaction,
NH + 202 + HCO^ -»• 3H20 + NO" + 2C02
and requires 7.2 Ib of alkalinity as CaC03 per Ib NH- as N oxidized.
The essential difference between the two reactions is that in
the first reaction one mole of alkalinity is produced in the oxidation
of Org N to NH., thereby, decreasing the net requirement from one
mole to two moles. In the second reaction, the same thing occurs,
but the mole of alkalinity produced is measured as part of the
influent alkalinity and the net requirement remains as two moles.
-------
60
It should be noted, however, that these reactions are an
oversimplification of an extremely complex biochemical reaction,
and may not yield the 2 to 1 or 1 to 1 molar ratios shown above.
On the basis of an average of the survey data obtained from all
four plants, approximately 7.5 Ib of alkalinity was required per
Ib of N02 + N0_ produced which is close to the maximum value of
7.2 ib for NH. ion oxidation and the biochemical simplification
made above may be sufficiently accurate for most purposes.
The nitrification reaction has been reported to be a
function of sludge age, organic loading, dissolved oxygen,
temperature and pH.
Each of these parameters are discussed with possible methods
for controlling nitrification where soft waters and associated
pH problems may occur.
3 /
Regarding sludge age, Eckenfelder^-'reports that the sludge
age or organism retention time must be greater than their growth
rate or they will be washed from the system. Generally, sludge
ages on the order of 5 days or greater are necessary for
nitrification. In extended aeration systems, the sludge age nearly
always exceeds five days and this is not a parameter which can
be controlled if it is desired to limit nitrification.
On the basis of organic loading, normally nitrification wm
start at a value of approximately 1.0 Ib BOD/ Ib MLSS at 20°C
in clarified sewage with essentially complete nitrification at
organic loadings of 0.2-0.3 Ib BOD5/lb MLSS. This is illustrated
by Figure 9.
-------
61
127
Regarding pH, it has been reported—'that the optimum pH
range is 7.5-8.5 with a decrease in pH causing a decrease in
nitrification. This may be one reason why the percent nitrification
was low in the systems studied.
Temperature is also an important variable affecting the
percent nitrification. The dependence of the growth rate of
197
Nitrosomonas sp. has been described by Downing—'to vary according
to the empirical relationship.
MT = M15 • 1.23(T"15) (7)
where
M,c = growth rate of Nitrosomonas sp.
15 at 15°C
MT = growth rate of Nitrosomonas sp.
1 at T°C
T = Temperature, °C
which indicates that a temperature change from 20°C to 10°C would
reduce the growth rate by a factor of approximately 3 and since
the percent nitrification would follow the growth rate of the
organisms, this would also be reduced by a factor of three.
A point that is noteworthy, particularly in regard to the
considerable effect of nitrification on pH and general system
efficiency is the high concentration of organic nitrogen in
the raw wastewater of the recreation areas studied. In general,
the concentration was nearly double that which is normally expected
from a domestic sewage. It can be seen, then, that a combination
of high organic nitrogen with low or even normal alkalinity could
-------
62
result in pH problems if a high percentage of nitrification occurs.
In addition to aeration pH problems, a high percentage of
nitrification in the aeration basin of an activated sludge system
may have a significant effect on the efficiency of the final
clarifier due to rising or floating sludge through denitrification.
Denitrification can be described by the equation
2 N0~ -»• 302 + N2 |
and can occur with a highly nitrified effluent in the final
clarifier because the active microbes continue their respiration.
If free dissolved oxygen is not available, oxygen is obtained
through reduction of the nitrates producing nitrogen gas which
bubbles off and floats the sludge. This sludge will not settle
once it has been floated and will be carried out of the clarifier,
thereby lowering the efficiency of the plant for suspended solids,
BODg and COD. The floating sludge noted at both Crystal and
Timberline is attributed to denitrification. This problem can
be controlled by reducing the sludge detention time in the clarifier.
It is generally recommended that this time be on the order of
four to six hours, but in practice, the sludge age can be used as
a good guideline. With a low sludge age, and a high oxygen
uptake rate, the time should be on the low side; say on the order
of four hours. However, if the sludge age is high and the oxygen
uptake rate is low, then a higher retention time can be used. This
can be controlled by the rate of sludge return to the aeration
basin. Long sludge retention times may have a practical application
-------
63
in some situations where the loading is very low during the week
and high during the weekends. It may then be possible to accu-
mulate and store the sludge for a day prior to expected heavy
loadings and then return it concurrent with the high loadings.
This then would reduce the effect of the shock load. This concept
21 /
of reducing shock loads has been expressed previously by Eckenfeldet—
and may, indeed, have application.
Solids Removal
As indicated by Figure 7, which gives the relationships
between sludge volume index, effluent suspended solids and organic
loading, the settleability of the sludge deteriorates rapidly at
organic loadings below 0.1 Ib COD/lb MLVSS-day. This is attributed
to two main factors: dispersed poor settling floe and filamentous
fungi.
It has been widely reported by Eckenfeldei—, McKinney—'and
others that at low organic loadings, a highly dispersed microbial
population develops that is composed of single cells and cell
fragments, which have very poor settling characteristics. Apparently,
this begins to occur at the areas studied at loadings below 0.1 Ib COD/
Ib MLVSS-day or approximately 0.05 Ib BOD5/lb MLVSS-day. The other
contributing factor is filamentous fungi which begin to develop
at pH levels below 6.0. Analysis of the sludge at both Crystal
Mountain and Timberline indicated significant concentrations of
fungi which is not surprising with the low aeration pH at these
-------
64
areas. The development of the fungi can also be attributed to
low loadings because of the relationship between organic loading
nitrifications and reduction in alkalinity and pH. As indicated
by Figure 9, significant nitrification began to occur at organic
loadings below 0.1 Ib BOD5/lb MLVSS-day.
Other factors that will effect the solids removal efficiency
is the hydraulic loading on the clarifier in terms of surface
loading (gpd/ft2) and the sludge detention time. If the surface
loading, which can also be equated to sludge rise velocity, exceeds
the settling velocity of the sludge, then the sludge will be
carried out of the system. At the four systems studied, the average
surface loading's were well below those values normally used
in design of activated sludge systems. However, when considering
the peak flow rates, the surface loadings were excessive, and in
all probability, contributed significantly to the solids carryover.
The sludge detention time is a factor because if it is too
long, the clarifier will tend to go anaerobic in the inner layers
of the sludge blanket, creating conditions for denitrification and
floating sludge. Since floating sludge was noted on several
occasions at both Timberline Lodge and Crystal Mountain, It
is surmised that both systems had long hydraulic detention times
/
in the clarifiers that allowed the development of anaerobic
conditions. The sludge return rate was not measured so that no
actual values can be computed for the clarifier detention times.
-------
DESIGN CONSIDERATIONS
In the design of an extended aeration activated sludge
system to treat a recreation waste, the following comments and
discussion are offered for the consideration of the design
engineer or the plant operator.
The organic loading should be considered, perhaps as the
most important variable involved and will be highly dependent
on having accurate waste flow and strength estimates. Since the
minimum load level of 0.05 Ib BOD5/lb MLVSS-day is considered
the critical level, the conservative design approach used by many
agencies and firms in the past cannot be considered adequate.
The maximum level will usually be dictated by the maximum
allowable soluble BODg in the effluent, but as a general rule
should probably be kept below 0.5 Ib BOD5/lb MLVSS-day.
The limitations in the sludge return system and levels of
MLVSS that can be maintained in the aeration basin will generally
dictate the average organic loading level to be used.
If the organic loading level is maintained in the range
discussed above, the sludge should not become highly dispersed,
but remain flocculent and the possibility of pH problems occurring
will be minimized. This is particularly true for ski areas where low
temperatures will also hold down the percent nitrification. It
should be noted, though, that if the raw waste has sufficient
s
alkalinity, then in most instances, it would be better to encourage
nitrification.
-------
66
It is recognized that much of the material presented in
this report lacks sufficient verification on which to base actual
design recommendations; and consequently, much of the material
is presented as information only. In the final report from the
Recreation Project, results will be presented on controlled
pilot plant studies that have been designed to answer many of
the questions that will arise. In addition, a recommended
design approach will be given that incorporates much of the
information presented in this report.
-------
BIBLIOGRAPHY
1. Clark, B. D. Basic Waste Characteristics at Winter Recreation
Areas. Progress Report, Pacific Northwest Water Laboratory,
Corvallis, Oregon, August 1968.
2. Standard Methods for the Examination of Water and Wastewater,
12th Edition, American Public Health Association, New
York, 1965.
3. Eckenfelder, W. W., Jr. New Design Advances in Biological
Treatment of Industrial Wastes, Seventeenth Annual
Meeting of Oklahoma Industrial Waste and Pollution
Control Conference, November 1966.
4. Macini, J. and E. C. Barnhart. Design of Aerated Lagoons,
Advances in Water Quality Improvement, University of
Texas Press, 1966.
5. Streeter, H. W. and E. B. Phelps. "A Study of the Pollution
and Natural Purification of the Ohio River," U. S. Public
Health Service Bulletin No. 196, 1925.,
6. Pohl, E. F. "The Effect of Low Temperatures on Aerobic Waste
Treatment Processes," Unpublished M.S. Thesis, University
of Washington, 1967.
7. Jenkins, P. and W. E. Garrison. "Control of Activated Sludge
by Mean Cell Resistance Time," Journal Water Pollution
Control Federation. Vol. 40, No. 11, Part 1, November 1968.
8. Eckhoff, D. W. and D. Jenkins. Transient Loading Effect in
The Activated Sludge Process, Proceedings - Third
International Conference of Water Pollution, Research,
Munich, WRCF, 1967.
9. Jenkins, D. and A. B. Menon. The Fate of Phosphorus in
Sewage Treatment Processes, Part I - Primary Sedimentation
and Activated Sludge. SERL, University of California,
Berkeley, California, 1967.
10. Eckenfelder, W. E. and D. J. O'Connor. Biological Waste
Treatment, Pergamon Press, London, 1961.
-------
68
11. Eckenfelder, W. E. "Comparative Biological Waste Treatment
Design," Journal Sanitary Engineering Division, ASCE,
Vol. 93, No. SA6, December 1967.
12. McKinney, R. E. Microbiology for Sanitary Engineers,'McGraw-
Hill Company, Inc., 1962.
13. Keefer, C. E. and J. Meisel, "Sewage and Industrial Wastes."
27, 3, 982, 1951.
14. Brower, 6. and L. Gaddis. "Filamentous Waste Treatment
Systems at Low pH," Journal Water Pollution Control
Federation, Vol. 41, 2, R61, February 1969.
15. Monod, J. "Reserches Sur la Croissance des Cutures Bacterounes."
Herman et Cie, Paris, 1942.
16. Smith, H. S. "Homogeneous Activated Sludge/2," Water and
Wastes Engineering. July 1967.
17. "Package Sewage Treatment Plants Criteria Development,
Part I, Extended aeration." National Sanitation
Foundation, Ann Arbor, Michigan, September 1966.
18. McCarty, P. L. and D. F. Broderson. "Theory of Extended
Aeration Activated Sludge," Journal Water Pollution
Control Federation, Vol. 34, No. 11, November 1962.
19. Downing, A. L. Population Dynamics in Biological Systems,
Third International Conference on Water Pollution
Research, Munich. 1966.
20. "A Study of Small, Complete Mixing, Extended Aeration, Activated
Sludge Plants in Massachusetts," New England Interstate
Water Pollution Control Commission, December 1961.
21. Eckenfelder, W. E., Notes on an informal lecture given by
Eckenfelder, Corvallis, Oregon. Sponsored by CH?M.
January 20, 1968.
-------
APPENDIX
-------
TABLE 3. TIMBE3LINE LODGE RAW SEWAGE
Analysis
Mg/1
BODt
BODC
CODt
C'ODg.
TS
TVS
SS
TVSS
Lab pH
Alk
Field pH
TP04
OP04
NH
3
N03
N02 .
KM
Cl
TH
CaH
1/21
485
245
899
540
853
586
420
390
8
294
7.3
12.6
6.8
-
-
-
89,2
-
26
22
1/22
540
340
9F
-
-
-
-
-
7.2
360
6.7
14.5
7.4.
-
-.
-
112.7
-
36
30
1/23
620
2:i5
994
-
620
474
480
400
6.5
112
6.0
12 A
6.7
-
0.12
0.06
49.3
-
36
31
1/24
460
225
868
377
570
414
380
300
6.5
96
6.0
9.8
4.7
-
0.2
0.08
44.6
-
27
22
1/25 1/26
330 450
215
827 869
459 320
1000
730
600
540
6.7
131
6.2
16.5
6.9
22.7
0.27 0.08
0.21 0.08
57.6 49.3
_
24
23
1/27
430
265
536
296
-
-
-
-
7.7
349
7.1
14.1
6.6
5.9
0.49
0.11
105.3
_
29
19
1/29
388
205
659
-
-
-
-
-
7.8
384
7.2
12.5
7.6
102
0.07
0.03
203.0
_
35
26
5/10
145
-
286
-
350
196
92
80
6.4
122
5.6
9.5
4.4
8.0
0.08
0.05
44.0
23
21
20
5/11
19P
-
533
-
432
180
156
130
-
130
5.5
14.9
7.7
16.9
0.59
0.08
56.0
13
40
37
5/12
280
-
710
-
570
448
244
212
6.0
115
5.7
9.7-
3.6
15.9
0.12
'0.08
32.4
14
' 23 ..
1
5/13
345
-
790
-
860
384
192
172
6.2
165
5.8
. . _ . .
-
•-
-
•'• T
-
.. 140
' 29 . -
25
Ave.
395
250
749
398
657
426
321
278
6.8
205
6,2
12.7
6.2
28.5
,. ...22
,09
76.6
48
.30
23
-------
TABLE 9. TIMBERLINE LODGE RAM SEWAGE (Continued)
Analysis 1/21 1/22 1/23 1/24 1/25 1/26 1/27 1/29 5/10 5/11 5/12 5/13 Ave.
Mg/1
Hours in
Composite 24 24 24 12 12 24 24 7 24 C/lL/ C/T C/T 19
Flow 12,400 10,400 6,000 4,800 9,800 5,200 9,200 12,000 3,800 5,700 15,800 5,200 8,358
!L/ C/T = Composited with time
-------
TABLE 10
TIMBERLINE LODGE AERATION
Date
1/20
1/21
1/22
1/23
1/24
1/25
1/26
1/27
1/28
1/29
3/22
3/23
3/24
3/25
3/26
5/10
5/11
5/12
5/13
SS mg/1
1375
2300
1720
1280
1740
2330
2620
2320
2300
2760
1888
-
2480
1620
1292
2300
2250
1900
1650
Analysis
TVSS mg/1
1250
2030
1520
1080
1520
2030
2280
2040
2000
2440
1641
-
2156
1416
984
2100
2100
1780
1480
Lab Field
pH pH
-
-
-
-
-
-
-
-
-
-
6.7 4.2
6.3
6.8 5.8
7.1 5.1
6.6 5.1
5.2 4.0
4.2
5.6 4.6
6.3 4.6
ALK mg/1
32
73
65
26
32
2
58
126
150
112
200
-
90
73
56
93
86
79
60
-------
TABLE 11
TIMBERLINE LODGE CLARIFIED
Analysis
Mg/1
BODt
BODC
COD
CODC
TS
TVS
SS
TVSS
PH
Alk
TP04
OP04
NH3
N03
N02
KN
TH
CaH
1/20 1/21
220
-
538 576
51a/
791
534
440
400
6.8
47
13.92
7.40
-
24.28 22.82
.84 .17
44.6 45.5
27
22
1/22
35
18
586
66b/
-
-
-
-
6.6
44
9.07
7.53
7.56
32.28
.25
56.4
26
22
1/23
43
16.5
106
63
-
-
-
-
4.5
-
9.69
7.31
12.80
31.50
1.14
14.0
39
29
1/24
34
12
90
64a/
416
238
32
20
4.2
-
9.80
6.48
9.70
30.80
<.01
10.2
49
32
1/25
45
6
287
404
194
-
-
3.9
-
9.69
6.89
5.60
30.30
<.01
24.3
42
26
1/26
15
4
67
51 a/
380
174
24
12
4.1
-
10.78
6.68
6.30
33.20
<.01
8.8
40
32
1/27
25
9
90
58a/
382
194
32
24
4.1
-
9.69
5.89
6.60
27.40
<.01
3.1
54
28
1/28
51
9
148
87a/
410
218
64
48
6.8
56
9.80
6.84
19.80
21.40
<.01
27.1
22
21
1/29
79
9
182
98a/
370
174
140
64
7.2
97
9.30
6.84
31.50
20.80
.49
34.7
22
18
3/22
90
8
370
102
-
- -
120
107
7.0
54
10.60
8.10
7.40
15.70
1.67
21.3
-
-
3/23
83
11
257
-
-
13
20
-
-
9.00
8.20
6.70
1.40
.75
21.7
-
-
3/24
138
11
305
-
-
172
156
4.9
3
11.20
8.00
15.70
5.97
1.05
29.6
-
-
3/25
80
9
210
-
-
56
60
5.7
6
10.10
7.00
15.50
4.47
4.69
27.9
-
-
3/26
73
8
288
-
-
48
36
6.9
27
11.10
6.40
9.80
6.79
8.67
24.0
-
-
5/10
44
8.5
128
71
-
-
76
64
4.8
17
9.40
6.90
<.10
1.13
.08
10.5
-
-
5/11 5/12 5/13
32 78 34
679
193 260 105
78 67 80
_
_
168c/ 281 c/ 44
151 a/ 253a/ 36
5.4 5.3
11 - 11
11.70 9.70 -
5.70 8.00 -
4.50 4.30 -
13.30 10.90 -
.40 4.87 -
16.1 20.1 -
- - -
_
- Estimated on basis of 1.31 mg COD/mg VSS
«, - Estimated on basis of BOD^ = 0.42 COD-10 (mg/1)
c/- Estimated on basis of 0.90 VSS/SS
-------
TKN as N
TABLE 12
CRYSTAL MOUNTAIN RAW SEWAGE
•I—
(/)
^
^
co
200
380
420
290
136
120
7.2
167
4.5
3.1
8.9
0.1
0.11
o
^
CO
330
710
1000
800
540
490
7.5
248
14.1
5.8
13.7
0.07
0.12
co
150
290
340
172
192
180
8.1
270
6.6
4.3
14.1
0.11
0.04
VO
CM
•*
183
310
504
364
168
164
6.7
167
5.1
3.5
8.2
0.2
0.06
r>.
CM
^
^1-
198
337
528
328
296
260
7
208
9.5
6.5
14.6
0.32
0.1
00
CM
•*
450
680
848
624
340
340
7.8
347
13.5
8.8
15.5
0.3
0.13
o>
CM
«*
740
1270
1160
896
780
780
7.7
283
17.3
11.6
23.4
0.07
0.21
112
103 60.0
72
83
94 114.4 40.5 54.1 70.3 51.3
42
59 126 118
-------
TABLE 12
CRYSTAL MOUNTAIN RAW SEWAGE (Continued)
(All values in mg/1 except pH, Color, and Flow)
(/>
•r- Or— CM co «* vo r-. co CT> o •— vo r«~ oo o>
(/> " i— r— i— i— i— i— i— i— i— CO CT> i— i— CM CM CM CM
>> >•» ^ . >•» '—. ^ ^ ^ ^ '—. ^.^"^^^ — -^^.-^
•— CVJCM cvjev4<\jcMcsjcv»
-------
TABLE 13
CRYSTAL MOUNTAIN AERATION
Date
2/10
2/11
2/12
2/13
2/14
2/15
2/16
2/17
2/18
2/19
3/8
3/9
3/10
3/11
3/12
4/26
4/27
4/28
4/29
BODt
1295
1520
1700
1625
1625
1600
-
1750
2275
2175
-
1650
700
6800
1038
1925
1118
863
938
(All values in mg/1 except pH,
BOD,, COD. COD,. SS TVSS
c t c
40
24
26
13
53
64
-
27
29
14
90
45
48
75
63
62
14
28
27
2904
3455
4355
4046
4498
3951
4689
4427
4345
4609
4900
4540
1270
4600
3900
7460
6440
3420
4480
195
153
188
190
207
202
309
357
198
178
-
-
-
-
-
320
264
180
180
2460
3640
3750
3830
3780
4250
3350
2750
4230
3950
3640
2400
3450
4080
3370
5680
4670
2920
3800
2120
3060
3280
3330
3300
3700
2900
2650
3750
3450
3170
2130
3060
3590
2970
5180
43501/
2700
3560
and temperature,
pH ALK NH3
7.0
7.3
7.2
6.8
-
-
7.2
6.9
7.0
6.9
6.5
6.8
7.0
7.1
6.5
6.5
6.4
7.0
6.9
-
262
276
154
68
50
186
173
225
130
129
134
176
155
71
-
178
160
144
43.5
51.6
.50.9
33.7
31.3
-
24.6
31.2
42.3
19.7
13.4
19.3
25.4
25.6
21.4
25.5
25.8
29.4
24.4
°C)
N03
10.00
.05
7.87
9.00
9.79
-
10.40
8.97
4.83
3.25
12.50
8.90
1.05
1.51
1.98
47.70
46.60
41.40
44.70
N02 KN
12.60 -
.18 285
18.70 309
30.60 284
27.90 261
-
25.30 247
22.20 202
21.10 243
22.20 -
8.24 117
11.70 114
1.64 220
1.94 249
1.20 65.4
.01 259
<.01 260
.02 162
.01 224
TEMP
6
4.5
5
3
2
1
1
5
5
6
6
6
6
6
6
3.5
5.5
5
6
a/= Estimated from COD data on basis of 1.42 mg COD/mg VSS
-------
TABLE 14
CRYSTAL MOUNTAIN EFFLUENT
Analysis
BODt
BODC
CODt
CODC
TS
TVS
SS
VSS
pH
Alk
Turb
Color
TPO,
0
CM
60
24
185
90
388
196
108
68
5.6
-
35
-
8.85
r—
•^
CM
66
32
153
97
324
172
92
64
7.6
130
-
75
8.40
All values in mg/1
CM co «3-
^ ^ ^
CM CM CM
47
18
129
83
332
176
24
24
7.8
176
50
75
8.20
150
12
243
88
448
228
112
104
7.4
109
33
75
8.70
330
9
876
159
900 1
620
660
570
-
69
-
-
22.10
except pH, turb(Jackson turbidity units) and color (Cobalt units)
in 10 !••» CO » >». ^»
CMCMCM CM CM CO CO CO CO CO «3"
318
24
976
133
130
820
700
610
-
22
-
-
18.30
78a/ 38
17a/ 17
171 200
90
476 450
250 280
144 52
120 48
6.5 6.0
31 20
41 38
80 60
9.40 10.40
56
17
271
86
580
388
100
100
7.0
123
25
80
10.30
205
16
328
89
368
184
232
204
7.3
156
20
40
10.20
65
18
150
53d/
284
152
74
36
6.1
13
27
40
5.60
64
18b/
163
53d_/
284
145
84
44
6.2
17
30
40
6.30
97
45
400
136d/
240
132
202
36
6.7
49
28
100
7.20
62
26
154
72d/
275
120
63
32c
6.9
72
27
75
9.10
62
26
160
72d/
530
370
67
48
6.3
23
32
120
7.10 1
53
17
289
51d/
472
264
182
56
5.9
14
35
75
0.30
r-
CM
*t
59
-
171
51
516
316
88
40
5.0
1
38
100
9.60
00
CM
<•
46
17
169
51 d/
460
256
90
48
5.3
3
36
100
9.90 1
-------
TABLE 14
CRYSTAL MOUNTAIN EFFLUENT (CONT'D)
—~ : All values In mg/1 except pH, turb(Jackson turbidity units; and color (cobalt units; ; ~~
£ 2^~£^££---coo^2:=2cS£i§3a
IQ pj{\|CMCMCMCMCMCMCMCMfOC')rOCOCO^'«d'<3'^-
c
<
OP04 5.94 5.90 5.90 6.00 6.80 9.80 9.00 9.00 8.20 7.30 4.10 4.80 5.50 7.30 5.50 9.10 9.10 9.00 -
NH3 16.2 44.7 56.3 46.3 23.3 - 16.1 17.0 28.9 38.0 10.7 11.6 22.4 29.5 24.6 26.6 24.5 24.5 28.5
N03 14.80 9.65 6.85 6.99 -36.20 - 37.0036.4023.00 3.73 7.00 5.70 .53 .49 .6845.6046.3044.9041.30
N02 15.60 13.80 13.80 20.30 1.30 - 1.25 1.33 1.53 12.20 15.90 17.20 1.99 2.43 2.81 .03 .01 .04 4.15
KN - 69,0 64.0 59.6 93.0 - 34.8 32.0 61.0 58.4 18.1 20.4 50.1 33.1 39.7 39.0 29.8 28.2 41.0
Cl 54 62 60 69 58 69 61 63 68 62 46 48 47 65 87 48 46 45 50
a/= estimated value oft basis of VSS and COD-p
B/= estimated value oh basis of comparison with data for 3/8
c/= estimated value on basis of average SS/VSS for 3/8, 9, 10, 12
d/= estimated value on basis of BOD5 = 0.42 COD-10
-------
TABLE 15 TIMBERLINE LODGE TREATMENT PLANT
FIELD DATA SHEET
Influent
Date
3/22/68
3/23/68
3/24/68
3/25/68
3/26/68
5/10/68
5/11/68
5/12/68
5/13/68
Temp.
°C
24.0
19.5
17.5
17.5
18.0
14.0
13.0
12.0
12.0
pH
7.3
6.8
6.9
6.8
6.9
5.6
5.5
5.7
5.8
Time
1130
1115
1135
1125
1130
0900
1030
0930
0930
Temp.
°C
14.2
13.5
14.5
13.5
12.5
10.5
10.0
10.0
10.0
Aeration
PH
4, 3
6.3
6.0
5.1
5.1
4.0
4.2
4.6
4.6
% Solids
16
0
17
15
11
70
75
72
63
D.O.a/
27.5
12.5
6.0
33.5
55
73
67
63
72
Time
1050
1120
1140
1140
1140
1000
0830
0815
1000
Temp.
°C
14.5
14.0
14.0
14.0
12.5
10.0
10.0
8.0
8.0
CLA
pH
5.2
6.1
6.4
6.5
5.4
5.3
6.0
6.0
6.0
EFF
Time
1140
1140
1150
1145
1145
1115
1200
1100
1105
Air Totalizer
Temp. RD6
°C gal
52050
52330
52924
53282
53478
9.0 71270
12.0 71550
4.5 72340
8.0 72600
i/ % Saturation
-------
TABLE 16. CRYSTAL MOUNTAIN
FIELD DATA SHEET
Influent
Date
2/08/68
2/09/68
2/10/68
2/11/68
2/12/68
, 2/13/68
2/14/68
2/15/68
2/16/68
2/17/68
2/18/68
2/19/68
3/08/68
3/09/68
3/10/68
Temp. °C
-
-
-
6.5
6.0
8.0
5.0
4.0
6.0
6.0
6.0
6.5
4.0
5.0
6.0
PH
-
-
-
6.3
6.1
6.6
6.7
-
6.5
6.7
6.2
6.4
6.9
6.7
6.7
Aeration
Temp. °C
-
-
6.0
4.5
5.0
3.0
2.0
1.0
1.0
5.0
5.0
6.0
6.0
6.0
6.0
PH
-
-
7.3
6.9
6.5
6.2
6.3
-
6.2
6.8
6.4
7.4
6.7
6.6
6.4
% Solids
-
-
31
42
75
45
43
47
45
49
75
74
80
75
80
D.O.
-
-
32
31
34
55
48
-
40
46
31
33
29
21
10
Final
Temp. °C
-
-
6.0
6.0
5.5
6.0
6.0
5.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
pH
-
-
7.1
6.7
6.8
6.3
6.5
-
6.4
6.6
6.9
7.2
5.5
6.5
6.6
Ai r
Temp. °C
-
-
7.0
0.0
1.0
-4.0
0.0
-7.0
-4.0
0.0
2.0
6.0
-4.0
-1.0
-1.0
-------
TABLE 16. CRYSTAL MOUNTAIN
FIELD DATA SHEET (CONT.)
Influent
Date
3/11/68
3/12/68
4/26/68
4/27/68
4/28/68
4/29/68
Temp. °C
6.0
6.0
6.0
6.0
6.0
7.0
PH
6.8
6.7
7.0
6.6
6.7
6.9
Aeration
Temp. °C
6.0
6.0
3.5
5.5
5.0
6.0
PH
6.5
6.6
6.9
6.0
6.0
6.0
% Solids
94
83
92
93
90
91
D.O.
14
23
64
29
30
59
Final
Temp. °C
6.0
6.0
4.0
5.5
6.0
6.0
PH
7.2
6.9
7.2
6.2
6.4
6.4
Air
Temp. °C
+1.0
+1.0
1.0
9.0
15.0
14.0
-------
TABLE 17. BULLARDS BEACH RAW SEWAGE
(All values in mg/1 except for pH)
Analysis-
Temp. °C
Flow, gpd
TS
TVS
SS
COD
BOD5
TOC
NH3
N02
N03
TKN
TP04
OPO
4
Alk
PH
TH
Fe
6/14/68
15.0
6957
300
--
24
147
50
32
30.1
.017
<.001
36.4
4.13
1.43
158
6.7
105
11300
6/15
15.0
7646
536
--
100
225a/
lOOb
48
37.7
.023
<.001
47
5.30
0.88
--
--
85
--
6/1 6 : 6/17
15.0 15.0
7816 8210
392
__
64
140
54a_/
36
37
.019
<.001
43
4.60
1.47
176
7.2
77
9.440
6/18
15.0
8065
370
--
100
193
82
40
42.2
.023
<.001
51
5.10
2.18
202
7.1
66
11.600
6/19
15.0
8262
396
--
100
220a_/
97
45
48.5
.027
<.001
58
7.10
3.20
233
7.2
69
8.720
6/20
15.0
8268
410
--
60
182
90
45
38.5
.009
..003
42.5
5.0
2.76
205
7.3
63
7.260
Ave.
15.0
7889
400.7
--
75
185
79
41
39
0.02
0.0013
46.32
5.2
195
7.1
77.5
9.664
a_/= Based on relationship, BOD5 = 0.525 COD-20
-------
TABLE 18. SUNSET BAY RAW SEWAGE
(All values in mg/1 except for pH)
Analysis
Temp. °C
Flow, gpd
TS
TVS
SS
COD
BOD5
TOC
NH3
N02
N03
TKN
TP04
OP04
Alk
PH
TH
Fe
6/14/68
17.0
12737
440
276
44
196
97
40
67.4
.021
.014
80
8.90
6.20
287
7.2
78
1740
6/15
16.0
14250
400
216
156
188
77
44
59.4
.016
.013
67
7.50
5.90
260
7.3
7.6
1090
6/16 6/17
16.0 16.0
12073 14573
416
156
40
171
78
42a/
59.5
.007
.009
79
8.40
6.00
262
7.4
90
1310
6/18
14.0
10826
450
196
48
175
75
43
68.3
.021
.004
72.9
--
—
286
7.4
77
1160
6/19
15.0
13166
388
216
28
208
82
47
68.5
.017
.004
72
--
—
297
7.3
63
1230
6/20
16.0
12546
480
276
36
189
81
45
71.7
.009
.026
71.5
--
—
303
7.4
70
1090
Ave.
15.7
12881.6
429
223
59
188
82
47
65.8
0.015
0.012
73.73
--
—
282.5
7.333
75.67
1270
Based on relationship of BODs = 3.28TOC-59
-------
TABLE 19. BULLARDS BEACH AERATION
Analysis
TVS mg/1
SS mg/1
Alk mg/1
pH
6/14/68
--
1280
19
5.85
6/15
--
900
19
5.7
6/16
--
920
37
6.2
6/17
--
1080
19
5.8
. 6/18
--
1200
25
5.9
6/19
--
neoi/
90
6.8
6/20
--
1120
93
6.6
Ave.
--
997.1
43.14
6.121
a/ = Estimated value
Analysis
TVS mg/1
SS mg/1
Alk mg/1
PH
6/14/68
700
780
52
6.4
TABLE
6/15
640
7601/
39
6.2
20.
6/16
660
740
69
6.7
SUNSET BAY
6/17
504
780
32
6.3
AERATION
6/18
800
860
58
6.6
6/19
960
760
82
6.7
6/20
1060
900
49
6.6
Ave.
760.6
717.1
54.43
6.5
a/= Estimated value
-------
TABLE 21. BULLARDS BEACH CLARIFIER EFFLUENT
Analysis
TVS
SS
COD
CODC
BOD
BODC
TOC
NH3
N02
N03
TKN
TPO>,
4
OPO,
4
• Alk
pH
Fe
6/14/68
28b
53
2i§y
33
8
17
11.2
.52
19.9
11.8
1.79
1.12
2
5.1
5.480
6/15
15b
37
20a/
18a/
7
16
13
1.18
20.1
14.6
2.57
1.26
8
5.9
5.810
6/16
28
62
29
36a/
13
20
14
1.16
20
21.2
3.70
1.59
4
5.5
6.170
6/17
20b_/
45a/
22
24
7
18
12.6
.84
21.4
16.9
2.15
1.43
2
5.4
2.542
6/18
48
66a_/
18a/
38
6
18
12
1.05
20.6
14.9
2.00
1.71
1
4.9
5.080
6/19
24b/
60
33
34
16a_/
18
13.4
1.13
21.5
13.5
2.29
1.90
3
5.2
4.360
6/20
10k/
45
33
24
16a/
18
13
1.14
24.8
11.2
3.40
2.40
3
5.7
2.180
Ave.
25
52.6
25.2
31
11.8
17.86
12.74
1.003
21.19
14.87
2.60
1.60
3.286
5.386
4.517
a/= Estimated from relationship BOD5 =0.67 COD-6.5
b/= Estimated from 1.15 mg COD/mgSS
-------
TABLE 21. SUNSET BAY CLARIFIER EFFLUENT(CONT.)
ANALYSIS
TVS
SS
COD
CODC
BOD
BODC
TOC
NH3
N02
N03
TKN
TP04
4
Alk
pH
Fe
6/14/68
168
9b/
26a/
16
11
4.5a/
12
24.7
.092
35.9
19.2
3
5.4
0.022
6/15
284
49b
76a/
20
45
7
13
24.4
.063
36.5
31.9
1
4.7
0.981
6/16
196
40b/
66
20
38
7
17
24.8
.06
36.4
25.5
1
4.7
0.581
6/17
256
3
24
22
10a/
8.5a/
19
30.1
.32
34.9
29.8
14
6.4
0.581
6/18
264
8b/
29
20
—
7
19
29
.065
40.2
20.1
1
5.3
0.291
6/19
264
24b/
44
16
23. 5a/
4.5
17
30
.12
40.1
22.1
5
5.8
0.254
6/20
740
4
24
19
10a/
6.5
16
29.2
.11
43.8
2
5.1
0.254
Ave.
310.3
20
25.29
19
21.6
6.4
16.14
27.46
.1186
38.26
24.77
3.857
5.343
0.441
ay= Estimated from relationship BODg = 0.67-COD-6.5
b/= Estimated from 1.15 mg COD/mgSS
-------
TABLE 22. SUNSET BAY
Field Data Sheet
Influent
Date
June 14
June 15
June 16
June 17
June 18
June 19
June 20
Temp.
17°C
16°C
16°C
16°C
14°C
15°C
16°C
pH
6.7
6.9
6.4
6.6
6.8
6.8
6.6
Time
1300
1330
1400
1430
1330
1330
1335
Temp.
13°C
13°C
14°C
13°C
13°C
14°C
14°C
Aeration
pH
5.2
5.5
5.1
5.3
5.4
5.3
5.1
%Solids
4
3
3
3
5
3
3
D.O.
4.8
4.2
4.5
4.7
4.0
4.4
4.7
Temp.
13°C
13°C
13°C
13°C
13°C
14°C
14°C
Effluent
pH
5.8
5.9
5.7
5.8
6.0
5.9
5.8
Totalizer
gallons
3730777
3745027
3757100
3771673
3782499
3795665
3808211
Air
Temp.
18°C
21 °C
13°C
14°C
12°C
14°C
14°C
-------
TABLE 23. BULLARDS BEACH
FIELD DATA SHEET
Influent
Date
6/14/68
6/15/68
6/16/68
6/17/68
6/18/68
6/19/68
6/20/68
Temp °C
15°
15°
15°
15°
15°
15°
15°
pH
7.8
7.4
7.2
7.6
7.7
7.5
7.7
Time
0900
0910
0930
0920
0906
0900
0905
Aeration
pH
5.4
5.6
5.3
5.5
5.6
5.6
'5.5
%Solids
7
5
3
8
5
10
9
D.O.
3.7
3.3
3.0
3.6
3.5
3.6
3.6
Effluent
Temp. °C
16°
17°
16°
16°
14°
15°
16°
PH
5.9
6.1
5.8
5.7
5.9
5.8
5.8
Cl Resid.
ing/1
.20
.22
.21
.24
.21
.22
.22
Air
Temp. °C
15°
15°
15°
15°
14°
16°
13°
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TABLE 24. AVERAGE COD ORGANIC LOADING AND EFFICIENCY
Area
Timber! ine Lodge
Crystal Mountain
Bui lards Beach
Sunset Bay
Date
1/21-29
5/10-13
2/11-19
3/08/12
4/26-29
6/14-20
6/14-20
Average
COD Loading
IbCOD/lbMLVSS-day
(Adjusted to 20°C)
0.084
0.051
0.125
0.138
0.049
0.126
0.245
Average COD
Removal Efficiency
Total
72.5
70.4
77.3
56.2
70.0
76.0
78.2
Centrifuged
92.1
87.3
90.6
83.6
92.0
89.0
90.0
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