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905R88102
FINAL SUPPLEMENTAL ENVIRONMENTAL IMPACT STATEMENT
Wastewater Treatment Facilities for the Columbus, Ohio Metropolitan Area
Prepared by the
United States Environmental Protection Agency
Region V
Chicago, Illinois
and
Science Applications
International Corporation
McLean, Virginia
With
Triad Engineering
Incorporated
Milwaukee, Wisconsin
August 1988
Approved by:
Valdas V. Adamkus
Regional Administrator
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APPENDIX A
BRIEFING PAPER NO. 1
WASTEWATER FLOWS AND LOADS
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• BRIEFING PAPER NO. 1
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WASTEWATER FLOWS AND LOADS
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• Supplemental Environmental Impact Statement
B USEPA Contract No, 68-04-5035, D.O. No. 40
I Columbus Ohio "Waste-water Treatment Facilities
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• Prepared By:
I SCIENCE APPLICATIONS INTERNATIONAL CORPORATION
| TRIAD ENGINEERING INCORPORATED
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WASTEWATER FLOWS AND LOADS
1. TERMS AND DEFINITIONS
2. AVAILABLE DATA
3. ANALYSIS OF AVAILABLE DATA
3.1 General
3.2 Dry Weather Flows
3.3 Water Usage
3.4 Wet Weather Flows
4. EXISTING AND PROJECTED FLOWS AND LOADS
4.1 Existing Wastewater Flows
4.1.1 Existing Average Flows
4.1.1.1 Infiltration
4.1.1.2 Industrial and Commercial Flows
4.1.1.3 Domestic Flows
4.1.2 Maximum Hourly Flows
4.1.3 Peak Process Flow
4.1.4 Wet Weather Flows
4.2 Existing Wastewater Loads
4.3 Projected Flows and Loads
5. FACILITY PLAN METHODOLOGY
5.1 Dry Weather Wastewater Flows
5.2 Design Average Daily Flows
5.3 Design Wastewater Loads
5.4 Industrial Flows and Loads
5.5 Projected Flows and Loads
5.5.1 Design Flows
5.5.2 Design Loads
6. COMPARISON OF BRIEFING PAPER AND FACILITY PLAN FLOWS AND LOADS
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INTRODUCTION
Under the direction of USEPA, a series of briefing papers are being
prepared addressing key issues in the development of the Supplemental
Environmental Impact Statement for the Columbus, Ohio, Wastewater Treatment
Facilities. The briefing papers form the basis of discussions between Triad
and USEPA to resolve important issues. The following paragraphs present the
background of the facility planning process, a description of the briefing
papers, and the purpose of this paper on flows and loads.
FACILITY PLANNING PROCESS
At the time this paper was prepared (March-August 1987) the city of
Columbus was proceeding to implement improvements at the Jackson Pike and
Southerly Wastewater Treatment Plants to comply with more stringent effluent
standards which must be met by July 1, 1988. These improvements were based
on the consolidation of wastewater treatment operations at the Southerly
plant. This one-plant alternative is a change from the two-plant operation
proposed by the city in the 1970's and evaluated in the 1979 EIS.
The development and documentation of wastewater treatment process and
sludge management alternatives for the Columbus metropolitan area has been an
extended and iterative process. The design and construction of various
system components have progressed, because of the 1988 deadline, while
planning issues continue to be resolved. As a result, numerous documents have
been prepared which occasionally revise a previously established course of
direction.
The concurrent resolution of planning issues and implementation of
various project components has made preparation of the EIS more difficult
because final facility plan recommendations are not available in a single
document.
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BRIEFING PAPERS
To facilitate preparation of the EIS, a series of briefing papers are
being developed. The purpose of the briefing papers is to allow USEPA to
review the work of the EIS consultant and to identify supplemental information
necessary for the preparation of the EIS. Six briefing papers are being
prepared as follows:
• Flows and Loads
• Sludge Management
• CSO
• Process Selection
• One Plant vs. Two Plant (Alternative Analysis)
• O&M and Capital Costs
The specific focus of each briefing paper will be different. However,
the general scope of the papers will adhere to the following format:
• Existing conditions will be documented.
• Evaluations, conclusions, and recommendations of the facilities
planning process will be reviewed using available documentation.
• Where appropriate, an independent evaluation of the future situation
and viable alternatives will be prepared.
• The facility plan and EIS briefing paper conclusions will be compared.
The briefing paper process is intended to:
• Prompt the resolution of any data deficiencies.
• Clearly establish and define existing and future conditions.
• Identify the final recommended plan which the city desires to implement.
• Provide a data base of sufficient detail to allow preparation of the
draft EIS.
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WASTEWATER FLOWS AND LOADS
This briefing paper presents an independent evaluation of wastewater
flows and loads which is based on an analysis of operating records from the
Jackson Pike and Southerly Wastewater Treatment Plants and the 1985 Revised
Facility Plan Update. The determination of wastewater flows and loads is a
key factor in the sizing of facilities, the evaluation of treatment alterna-
tives, and the evaluation of solids management scenarios. Design flows and
loads are presented for the 20-year planning period which ends in 2008. This
document is divided into six sections.
• Terms and definitions
• Available data
• Analysis of available data
• Existing and projected flows and loads
• Facility plan methodology
• Comparison of facility plan and briefing paper flows and loads
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1. TERMS AND DEFINITIONS
BOD or Biochemical Oxygen Demand: An index of Che amount of oxygen required
for the biological and chemical oxidation of the organic matter in a liquid.
Combined Sewer: A sewer which transports both wastewater and storm or surface
water in a single pipe.
Commercial/Industrial Flow: Wastewater flows from commercial businesses and
industry.
Design Average Flow; The 24-hour average flow which the upgraded and expanded
treatment facilities will be sized and designed to process.
Diurnal Peaking Factor; The factor applied to the design average flow to
account for the maximum flow rate occurring at the wastewater treatment plant
over a given 24-hour period. The peaking factor is calculated as the maximum
hourly flow rate divided by the average hourly flow rate.
Domestic Flow; Residential sewage flow.
*Dry Weather/No Bypass Flow Condition: Dry weather days when there were no
reported raw or settled sewage bypasses at the Southerly WWTP and no recorded
hours of operation at the Whittier Street Storm Tanks.
*Dry Weather Flow Condition: Any day when precipitation does not occur on a
particular day or during the day immediately preceding it.
Effluent; The flow out of a process.
High Groundwater Infiltration: Infiltration to sewers that occurs during
periods of extended wet weather when the level of the groundwater is high.
Infiltration; Water other than wastewater that enters a sewerage system,
including sewer service connections, from the ground through such sources as
defective pipes, pipe joints, connections, or manholes. Infiltration does not
include, and is distinquished from, inflow.
Inflow or RainJLnduced Flow: Water other than wastewater that enters a
sewerage system, including sewer service connections, from sources such as
roof leaders, cellar drains, yard drains, area drains, foundation drains,
manhole covers, cross connections between storm sewers and sanitary sewers,
catch basins, cooling towers, storm waters, surface runoff, street wash
waters, or drainage. Inflow does not include, and is distinguished from,
infiltration.
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Force Main: A sewer conduit which is pressurized by pumping.
Influent: Flow into a process.
Low Groundwater Infiltration; Infiltration that occurs during periods of
extended dry weather when the level of the groundwater is low.
Sanitary Sewer: A conduit intended to carry liquid and water-carried wastes
from residences, commercial buildings, industrial plants, and institutions
together with minor quantities of ground, storm, and surface waters that are
not admitted intentionally.
Storm Sewer: A sewer designed to carry only storm waters, surface run-off,
street wash waters, and drainage.
*Wet Weather Flow Conditions: Any day (or days) on which measurable precipi-
tation occurred and the single day following any day on which precipitation
occurred. The day following any day on which precipitation occurred is
defined as wet weather due to the lag in the peak rain-induced flow which is
seen at the plants as a result of in-system travel time. Defining the
following day as wet weather also accounts for the effect of in-line storage
following extended periods of wet weather.
*These definitions were developed for the analysis contained in this document.
They are not standard definitions.
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2. AVAILABLE DATA
The 1985 and 1986 operating records from Che Southerly and Jackson Pike
WWTPs were reviewed to determine existing and projected design flows and
loads. The following plant records were obtained from the city of Columbus
and Ohio EPA.
• Monthly Operating Reports for both plants from January 1985 through
December 1986.
• Monthly Report of Operations for the Jackson Pike WWTP from January
1985 through December 1985.
• Monthly Report of Operations for the Southerly WWTP from January 1985
through September 1986.
• Hours of operation of the Whittier Street Storm Tanks from January
1985 through December 1986.
• Hourly flow data for both plants for February and September 1985.
• 1985 monthly water consumption records for the Columbus Area.
• 1983 Industrial Pretreatment Report - Malcolm Pirnie.
• Sewer lengths and sizes for the Columbus Sewer System.
The Monthly Operating Reports (MORs) are submitted to Ohio EPA in
accordance with the NPDES permits. Influent flow and load data were obtained
from these reports. However, these reports did not contain precipitation
data. This information was obtained from the Monthly Report of Operations
which is submitted to the Ohio Department of Health.
The Southerly MORs include data on amounts of raw sewage bypassed and
settled sewage bypassed as well as treated flow. The Southerly plant has a
method of treatment termed Blending of Flows. When incoming flows increase to
the point where the biological portion of the plant begins to show signs of
potential washout, the flow to the biological part of the plant is fixed. The
increase in flow above this fixed flow, but less than the capacity of the
primary tanks, is bypassed around the biological portion and blended with the
final effluent, thus, receiving only primary treatment and chlorination.
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These flows are reported on Che MORs as settled sewage bypassed. If the
primary treatment facilities are operating at capacity, then all excess flows
are bypassed directly to the Scioto River through a 108-inch diameter pipe
originating in the screen building. These flows are reported on the MORs as
raw sewage bypassed. After August of 1986, no blending of flows was recorded
in the MORs for the Southerly WWTP, however, bypassing was still reported.
The Jackson Pike MORs provide flow monitoring data for the plant.
Jackson Pike does not blend as Southerly does, nor do they bypass raw sewage.
The major diversion point for Jackson Pike flows occurs at the Whittier Street
Storm Tanks before the flows even reach the plant. The tanks are capable of
acting as a holding system for the excess flows until the flow in the
interceptor subsides and they can be bled back into the system and carried to
the Jackson Pike plant. If the flows exceed the capacity of the tanks, they
overflow to the Scioto River. Flows can also be directly bypassed along side
the tanks, through an emergency bypass, to the Scioto River.
Flow monitoring did not take place at the Whittier Street Storm Tanks
until November of 1986. However, hours of operation of the storm tanks were
recorded during 1985 and 1986 on the Monthly Report of Operations. The fact
that hours of operation were reported does not necessarily mean there was
bypassing or overflowing occurring at the tanks. It only means that the gates
were open and flows were being diverted into the tanks. In November of 1986,
the city began monitoring the overflow but not the bypass. Therefore, the
data is still incomplete with respect to determining the total volume of flow
entering the Scioto River at the Whittier Street facility.
Hourly flow data was obtained for February and September of 1985 for both
plants. These months represent the periods of minimum and maximum water
consumption respectively. This hourly flow data was used to determine a
diurnal peaking factor which is calculated by dividing the peak hourly flow by
the average hourly flow. This diurnal peaking factor is multiplied by the
design average flow to determine a peak hourly flow for use in sizing the wet
stream treatment facilities.
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Dry weather flows were determined through an analysis of 1985 and 1986
flow data. However, only 1986 flow data was used to determine wet weather
flows. An analysis of 1985 MORs showed that data on raw and settled sewage
bypasses at Southerly were not complete. Up until August of 1985, only a
bypass flow rate (MGD) was reported with no duration specified. These
bypasses did not always occur 24 hours a day, therefore, these rates could not
be converted to the volume bypassed during that day. In August of 1985,
monitoring of the duration of the bypasses began which provided a more
accurate determination of the volume of the bypasses. Therefore, the 1986
calendar year data were used to estimate wet weather flows.
Wet weather total system flow can not be determined solely based on the volume
of flow arriving at the Jackson Pike and Southerly WWTPs. There are numerous
points of combined sewer overflow throughout the Columbus Sewer System. The
Jackson Pike service area has several regulator chambers and overflow
structures in addition to the Whittier Street Storm Standby Tanks discussed
previously. The Southerly service area includes an overflow structure at
Roads End and the Alum Creek Storm Standby Tank. There is no comprehensive
flow monitoring data available for the regulators, overflows, and storm tanks.
The city began monitoring the overflows at the Whittier Street facility in
November of 1986. However, they did not monitor the bypass line at the
Whittier Street facility. The city also began monitoring some of the other
points of combined sewer overflow; but according to the MORs, the flow
monitoring equipment malfunctioned frequently which provided no data. Thus,
the only flow data included in the wet weather analysis, other than plant flow
data, was that which was reported for the Whittier Street overflow during
November and December.
The Industrial Pretreatment Report prepared by Malcolm Pirnie in 1983 was
used to estimate the industrial and commercial flows. This report quoted
figures on industrial and commercial flows based on 1980 water and sewage
records. Due to the lack of more recent quantification of industrial and
commercial flows, these figures were updated for this document using 1985
population figures.
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3. ANALYSIS OF AVAILABLE DATA
The following sections present an analysis of the wastewater flow data.
This analysis was developed independently of that presented in the facility
plan as a check of the assumptions and methodologies. It was prepared using
Monthly Operating Reports (MORs) for the Jackson Pike and Southerly WWTPs and
precipitation data and water usage records for the city of Columbus. Using
these records, wet weather and dry weather flows were developed for each
plant. Dry weather flows were compared to water consumption data to aid in
the interpretation of monthly flow variations.
3.1 GENERAL
Jackson Pike and Southerly MORs and precipitation data for the 1985 and
1986 calendar years were used to establish existing wastewater flows. The
following sections will discuss existing wet weather and dry weather flows.
In order to determine wet and dry weather flows, each daily record was
categorized accordingly. Wet weather was defined as any day on which
measurable precipitation occurred and the single day following the last day on
which precipitation occurred. The day following one on which precipitation
occurred is defined in this analysis as wet weather due to the lag in the peak
rain induced flow which is seen at the plants. This lag is a result of in-
line storage and in-system travel time. The remainder of the daily records
were categorized as dry weather. Weather conditions for 1985 and 1986 are
summarized in Table 3-1 using these classifications. There were a total of
144 days in 1985 and 130 days in 1986 on which measurable precipitation
occurred. Wet weather days totaled 212 for 1985 and 197 for 1986. There were
153 dry weather days for 1985 and 168 for 1986.
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TABLE 3-1. WEATHER CONDITION SUMMARY
Precipitation* Days of Measurable Wet Weather Dry Weather
Month (inches) Precipitation (Count) Days (Count) Days (Count)
1985
January 1.26 16 21 10
February 1.67 12 17 11
March 3.78 17 24 7
April 0.56 11 17 13
May 4.96 12 17 14
June 1.41 12 20 10
July 6.88 5 7 24
August 2.34 10 16 15
September 1.18 4 6 24
October 1.98 11 18 13
November 10.67 21 28 2
December 1.81 13 21 10
TOTAL 38.50 144 212 153
1986
January 1.54 12 16 15
February 2.96 16 22 6
March 2.61 11 17 14
April 1.31 13 21 9
May 2.47 13 19 12
June 5.53 11 17 13
July 3.60 8 13 18
August 1.61 6 11 20
September 3.44 8 13 17
October 4.16 9 13 18
November 3.00 11 18 12
December 2.81 12 17 14
TOTAL 35.04 130 197 168
* Measured at Port Columbus Airport
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3.2 DRY WEATHER FLOWS
Construction Grants 1985, which is the USEPA guide for the preparation of
facility plans, recommends that design flows for treatment works be determined
based on existing base flow; estimated future flows from residential, com-
mercial, institutional and industrial sources; and nonexcessive I/I.
Traditionally, base flows are established using dry weather flow.
Dry weather days were classified as indicated in the previous section.
By definition, they include any day on which measurable precipitation does not
occur that day or during the day immediately preceding it. In applying this
definition to plant data, it was found that bypasses occurred in the system on
several days which would be categorized as dry weather. Bypasses are
monitored at the Southerly WWTP and reported in the records as settled sewage
bypassed and raw sewage bypassed. The Jackson Pike WWTP does not bypass at
the plant. However, when flows increase beyond plant capacity, the gates are
opened at the Whittier Street Storm Tanks and flows are diverted to the tanks
before they reach the Jackson Pike WWTP. When the gates are open at the
Whittier Street facility, it is considered to be in operation. Flows diverted
through the Whittier Street Storm Tanks were not monitored until November of
1986, but the hours of operation of the storm tanks are reported on the
Jackson Pike WWTP records. Days with reported hours of operation were
considered as bypass days.
Closer examination of the days with reported bypassing and storm tank
hours showed that the majority occurred after an extended wet weather period.
Those that did not follow an extended wet weather period were assumed to be
related to operational problems at the plant. Therefore, in establishing dry
weather flows, only dry weather/no bypass days were considered.
Using the classification of dry weather/no bypass, monthly average flows
were determined for the 1985 and 1986 calendar year. These flows are
presented in Table 3-2. In evaluating these flows, the 1985 and 1986 averages
for each plant were very close. The maximum and minimum combined values both
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TABLE 3-2. DRY WEATHER/NO BYPASS MONTHLY AVERAGE FLOWS (MGD)
Month
1985
January
February
March
April
May
June
July
August
September
October
November
December
TOTAL
AVERAGE
1986
January
February
March
April
May
June
July
August
September
October
November
December
TOTAL
AVERAGE
Count
7
5
2
3
8
9
19
11
24
11
0
5
104
10
0
1
8
11
10
13
20
17
10
2
8
110
Jackson Pike
75.86
79.20
82.00
81.30
83.88
78.89
80.47
75.18
73.38
72.31
ND
81.62
77.27
78.53
ND
80.73
82.52
76.66
80.33
81.32
77.13
75.87
78.08
70.30
79.06
78.33
Southerly
56.44
60.74
60.55
58.92
60.88
55.14
58.40
51.85
50.64
52.57
ND
61.54
55.40
56.23
ND
62.50
57.69
48.21
58.34
55.79
55.74
55.18
53.25
54.30
60.98
55.52
Combined
132.30
1 39 . 94
142.55
140.22
144.76
134.03
138.87
127.03
124.02
124.88
ND
143.16
132.67
134.76
ND
143.23
140.21
124.87
138.67
137.12
132.87
131.05
131.33
124.60
140.04
133.85
ND - No dry weather/no bypass days
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occurred in 1985. The dry weather combined maximum monthly average of 145 MGD
occurred in May of 1985, and the dry weather combined minimum monthly average
of 124 MGD occurred in September of 1985.
The maximum monthly average dry weather flow of 145 MGD which occurred in
May is considered to represent a high groundwater condition due to the large
amount of precipitation and extended wet weather periods in this month. It
had the second highest monthly precipitation for 1985 of 3.92 inches. The
highest occurred in November, but there were no dry weather/no bypass days in
November. May had eight dry weather/no bypass days which occurred during two
4-day periods.
The minimum monthly average dry weather flow of 124 MGD which occurred in
September of 1985 is considered to represent a low groundwater condition due
to the extended dry period which occurred during that month. September of
1985 had 24 dry weather/no bypass days which occurred during one 22-day period
and one 2-day period. This was the highest number of dry weather/no bypass
days recorded in one month for the 24 month (1985 and 1986) data base that was
evaluated.
The 1985 flows closely approximate the 1986 dry weather/no bypass maximum
monthly average of 143 MGD and the minimum monthly average of 125 MGD.
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3.3 WATER USAGE
Information on water usage for the Columbus area was obtained from the
Columbus Division of Water - 1985 Annual Report. These flows were evaluated
to gain further insight into the groundwater condition. The total amount of
water pumped to residential, commercial, and industrial customers in the
Columbus area during the 1985 calendar year was 44 billion gallons. Using
the 1985 population figure of 870,000 people, developed by Ohio Data Users
Center, the water usage figure was converted to 139 gallons per capita per day
(gpcd).
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The L985 average dry weather/no bypass flow of 136 HGD from Table 3-2 can
be converted Co 156 gpcd using the population figure for 1985 of 870,000
persons. The per capita water pumpage (139 gpcd) value is 17 gpcd or approxi-
mately 12 percent less than the wastewater (156 gpcd) value. This 17 gpcd
difference may be the result of high infiltration in the sewer system, not all
the sewer customers being water customers, or a result of illegal connections
to the sewer system.
Table 3-3 compares the monthly average water pumped to the Columbus area
vs. monthly average dry weather/no bypass wastewater flows. The table shows a
higher wastewater flow than water pumpage for the spring months. This could
be due to more sewer customers than water customers as discussed in the
previous paragraph. However, it could also be a result of a greater amount of
infiltration from a high groundwater condition. September, on the other hand,
which had 24 dry weather/no bypass days had an average water pumpage figure
17.72 MGD greater than the wastewater figure. The high water purapage figure
could be attributed to lawn sprinkling due to the extended dry period. The
low wastewater flow indicates that less infiltration is entering the system,
which is a result of a low groundwater condition.
TABLE 3-3 1985 WATER PUMPAGE VS. WASTEWATER FLOW
Month
January
February
March
April
May
June
July
August
September
October
November
December
Average Water
Pumped (MGD)
111.23
108.32
109.65
115.60
120.33
128.53
127.15
130.66
141.74
124.88
117.23
116.46
Average Dry Weather/
No Bypass Flow (MGD)
132.30
139.94
142.55
140.25
144.75
134.03
138.87
127.03
124.02
124.88
ND
143.16
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3.4 WET WEATHER FLOWS
A limited data base was reviewed with respect to wet weather flows.
Insufficient data was available to quantify the total wet weather flow for the
entire Columbus system.
The only data evaluated in determining wet weather flows was that which
was reported from monitoring flows arriving at the plants from January through
December 1986 and data reported from monitoring overflows at the Whittier
Street Storm Tanks during November and December of 1986. The flow data
collected at the Southerly and Jackson Pike plants is the only data that was
collected for an entire year. Flow data was collected at the overflow located
at the Whittier Street Storm Tanks during November and December of 1986.
However, no flow data was gathered from the bypass at Whittier Street. From
October through December of 1986, flow monitoring was performed at various
other overflows and regulators within the Columbus combined sewer system.
However, it was never performed at all the points of combined sewer overflow
during the same month, and according to the MORs, the flow monitoring
equipment malfunctioned frequently.
Wet weather days were categorized as discussed in Section 3.1. Wet
weather being defined as any day on which measurable precipitation occurs and
the single day immediately following any day on which measurable precipitation
occurs.
A total flow was calculated for each wet weather day during 1986. This
total flow includes the following:
• Southerly treated sewage.
• Southerly settled sewage bypassed.
• Southerly raw sewage bypassed.
• Jackson Pike treated sewage.
• Whittier Street sewage overflow volumes (November and December only).
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Table 3-4 shows Che average and maximum daily wet weather flows for
January through December of 1986. As shown in the table, the maximum wet
weather flow of 309.52 MGD occurred in March. The actual day was March 14,
1986. On March 12, the reported precipitation was 0.71 inches and 0.51 inches
was reported for March 13. It must be remembered that this flow only
includes the flow arriving at the plants. It does not include any bypassing
that may have occurred at the numerous points of combined sewer overflow
throughout the system.
Wet weather flows are discussed in more detail in the CSO briefing paper.
TABLE 3-4. WET WEATHER FLOW DATA
Wet Weather
Maximum
Month
January
February
March
April
May
June
July
August
September
October
November
December
Total
1986
Days (Count)
16
22
17
21
19
17
13
11
13
13
18
17
197
Daily Average (MGD)
165.31
298.62
309.52
155.02
160.98
227.60
184.29
158.61
165.23
266.00
223.73
294.24
309.52
Average (MGD)
147.73
183.01
181.62
143.68
137.46
152.45
154.75
137.00
147.27
161.47
149.80
178.64
156.24
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4. EXISTING AND PROJECTED FLOWS AND LOADS
This chapter describes the development of average daily and peak hourly
flow rates and daily loadings of TSS (total suspended solids) and BOD which
are used to evaluate facility planning recommendations. The following sections
present the existing flows and loads developed for the Columbus WWTPs from an
independent analysis of the 1985 and 1986 plant data, as well as projected
flows and loads for the 2008 design year.
An analysis of existing conditions established the current average day
flows. This current condition is subsequently dissagregated into domestic,
infiltration, industrial, and commercial flows. A diurnal peaking factor and
a process peaking factor are established to project peak flow rates which will
be used in sizing some of the WWTP unit processes. Wet weather flows are
discussed briefly with a more detailed discussion included in the CSO packet.
The analysis also includes a review of existing influent BOD and TSS
loads. BOD and TSS loads are used to determine sizings for WWTP unit
processes and to aid in the selection of the alternative treatment processes.
Wastewater flows and loads are projected for the design year (2008) using
existing per capita flows and loads and 2008 population projections.
4.1 EXISTING WASTEWATER FLOWS
This section presents the existing average flow, maximum hourly flow,
peak process flow, and wet weather flow as determined from analysis of
available data.
4.1.1 Existing Average Flows
According to USEPA guidelines, WWTP design flows are determined based on
existing dry weather flows and non-excessive I/I. As discussed in Section
3.2, dry weather flows were determined based on a dry weather/no bypass
condition. Therefore, the existing average flow was determined through an
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analysis of dry weather/no bypass flows. The 1985 and 1986 combined Jackson
Pike and Southerly maximum monthly average dry weather/no bypass flow from
Table 3-2 was selected. This combined flow of 144.76 MGD occurred in May of
1985 and was based on 83.88 MGD for Jackson Pike and 60.88 MGD for Southerly.
In subsequent paragraphs, this flow of 145 MGD is further broken down into
infiltration, industrial, commercial, and domestic flows. In Section 4.3,
population projections are used to increase this flow for the design year.
4.1.1.1 Infiltration
No current infiltration/inflow report was available for the Columbus
sewer system; therefore, wastewater flow, water use, and precipitation data
were evaluated to estimate infiltration.
The maximum monthly average dry weather/no bypass flow of 145 MGD
occurred in May of 1985. The data base consists of two 4-day periods of dry
weather/no bypass conditions. This month, which had 3.92 inches of
precipitation, had the second highest monthly rainfall recorded during 1985.
Therefore, it is safe to assume that May would represent a high groundwater
condition resulting in increased infiltration. November had the highest
precipitation with 10.67 inches, but there were no dry weather/no bypass days
during that month.
September of 1985 had the lowest combined monthly average dry weather/no
bypass flow of 124.02 MGD for the 1985 and 1986 calendar years; and it had
24-dry weather/no bypass days which occurred in one 2-day period and one
22-day period. Due to the extended dry weather period, it is assumed to
represent a low groundwater condition. Water usage figures presented in
Section 3.3 reinforce May and September as representing high and low
groundwater conditions. The difference of 20.74 MGD between the high
groundwater month (May) and the low groundwater month (September) represents
that portion of the total infiltration which is attributable to a high
groundwater condition. However, this is only a portion of the total amount of
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infiltration occurring since there is also some infiltration occurring during
low groundwater conditions. Therefore, the amount of infiltration occurring
during low groundwater conditions must be determined and added to the 20.74
MGD in order to establish a total infiltration rate.
In the absence of a current infiltration/inflow report other methods of
estimating infiltration must be used. A common method involves using monthly
water records to establish the domestic, commercial, and industrial portion of
the wastewater flow. The remainder of the wastewater flow is then assumed to
be infiltration.
Since September 1985 has been established as a low groundwater month,
water usage rates from this month will be used. As reported in Table 3-3, the
September 1985 water pumpage rate is 141.74 MGD. Literature states that
approximately 60 to 80 percent of water becomes wastewater. The 20 to 40
percent which is lost includes water consumed by commercial and manufacturing
establishments and water used for street washing, lawn sprinkling, and
extinguishing fires. It also includes water used by residences that are not
connected to the sewer system as well as some leakage from water mains and
service pipes. If it is assumed that 70 percent of the water becomes
wastewater, then the return flow for September would be 99.22 MGD. Referring
to Table 3-3, the wastewater flow for September is 124.02 MGD. The difference
between the actual wastewater flow (124.02) and the expected wastewater flow
(99.22) is 24.80 MGD. This value is assumed to represent the amount of
infiltration occurring during a low groundwater condition. Thus, the total
infiltration occurring during high groundwater conditions is obtained by
adding 20.74 MGD to 24.80 MGD. This total infiltration figure of 45.54 MGD,
converts to 52 gpcd.
It must be remembered that 52 gpcd is only a rough estimate of
infiltration. It is not known if all of the water customers are sewer
customers or if all the sewer customers are water customers. Some sewer
customers may have their own private wells. In addition, the consumptive use
of the brewery and the other industries is unknown.
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It is, however, considered to be a non-excessive infiltration rate when
compared to infiltration rates in the USEPA document entitled Facility
Planning - 1981 Construction Grants Programs. This document states that 2000
to 3000 gpd/inch-diaraeter mile is considered a non-excessive infiltration rate
for sewer systems with lengths greater than 100,000 feet. The Columbus Sewer
System has a total length of 9,975,000 feet which converts to an estimated
32,930 inch-diameter miles. Multiplying the inch-diameter miles by 2000
gpd/inch-diaraeter mile results in 66 MGD or 76 gpcd. Therefore, 52 gpcd of
infiltration would be considered non-excessive.
The Revised Facility Plan Update uses a peak infiltration rate of 72
gpcd. Divided between the two plants, it is 82 gpcd for Jackson Pike and 58
gpcd for Southerly. Assuming more detailed information was available to
establish this number for the facility plan and considering 72 gpcd is also a
non-excessive infiltration rate according to the USEPA document, it will be
used in this briefing paper as the existing infiltration rate. It converts to
22.1 MGD for Southerly and 40.1 MGD for Jackson Pike, totaling 62.2 MGD for
the entire Columbus Sewer System. This number will be held constant through-
out the planning period.
4.1.1.2 Industrial and Commercial Flows
»•
Current information on industrial and commercial wastewater flows was not
available. Therefore, estimates were made by updating those values presented
in the Columbus Industrial Pretreatment Program Report as prepared by Burgess
and Niple. The Burgess and Niple values were updated proportional to the
increase in population from 1980 to 1985 since they were based on 1980 water
consumption records. The 1985 Estimates of industrial and commercial flows
are presented in Table 4-1.
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TABLE 4-1. INDUSTRIAL AND COMMERCIAL FLOW ESTIMATES
1980 1980 1985 1985
1980 Industrial Commercial 1985 Industrial Commercial
Population Flow (MGD) Flow (MGD) Population Flow (MGD) Flow (MGD)
Jackson Pike 472,503 8.7 4.3 489,000 9.0 4.
Southerly 368,228 6.7 3.1 381,000 6.9 3.
TOTAL 840,731 15.4 7.4 870,000 15.9 7.
The analysis of variations in the dry weather/no bypass flows between
weekdays and weekends gives an indication of the magnitude of the industrial
and commercial flows. Table 4-2 presents a summary of the weekly flow
variations for the two plants.
TABLE 4-2. 1985 DRY WEATHER/NO BYPASS WEEKLY FLOW VARIATIONS (MGD)
Jackson Pike Southerly TOTAL
Weekday 78.71 55.37 134.08
Weekend 73.80 54.92 128.72
Difference 4.91 0.45 5.36
% Difference 6.2 0.8 4.0
From Weekday
Referring to Table 4-1, it can be seen that the total commercial and
industrial flow for Jackson Pike in 1985 is 13.5 MGD. Relating this to the
4.91 MGD difference in flow between weekdays and the weekend, suggests that
approximately 35 percent of the flow from commercial and industrial sources
in the Jackson Pike service area is from sources which operate on a weekday
schedule. Southerly, on the other hand, with 10.1 MGD industrial and
commercial flow, appears to have only 4 percent of its industrial and
commercial contributing flow sources operating on a weekday schedule.
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4.1.1.3 Domestic Flows
Domestic flows were estimated simply by subtracting infiltration,
industrial, and commercial flows from the maximum dry weather/no bypass flow
of 145 MGD. The Jackson Pike domestic flow is 30.4 MGD and Southerly is 28.8
MGD. Table 4-3 presents the breakdown of the existing flow for each plant and
the two plants combined.
TABLE 4-3. 1985 ESTIMATED FLOWS
Jackson Pike Southerly Total
Design Average 84 61 145
Flow (MGD)
• Infiltration 40.1 22.1 62.2
• Industrial 9.0 6.9 15.9
• Commercial 4.5 3.2 7.7
• Domestic 30.4 28.8 59.2
4.1.2 Maximum Hourly Flow
Just as demand for water fluctuates on an hourly basis, so do wastewater
flow rates. Fluctuations observed in wastewater flow rates tend to follow a
diurnal pattern. (See Figure 4-1.) Minimum flow usually occurs in the early
morning hours when water use is low. The flow rates start to increase at
approximately 6 a.m. when people are going to work, and they reach a peak
value around 12 noon. The flow rate usually drops off in the early afternoon,
and a second peak occurs in the early evening hours between 6 p.m. and 9 p.m.
In general, where extraneous flows are excluded from the sewer system, the
wastewater flow-rate curves will closely follow water-use curves. However,
the wastewater curves will be displaced by a time period corresponding to the
travel time in the sewers.
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Diurnal curves are also affected by Che size of the community. Large
communities with more industrial and commercial flows tend to have flatter
curves due to industries that operate on a 24-hour schedule, stores and
restaurants that are open 24 hours a day, and to the expansiveness of the
collection systems. These 24-hour operating schedules also result in more
people working second and third shift, thus altering normal flow patterns.
Longer travel times in the collection system dampen peak flows observed at the
WWTP.
An existing average flow of 145 MGD was determined in Section 4.1.1.
This flow was determined from average dry weather flows and it is generally
used in the design of wastewater facilities to determine quantities of
chemicals needed, O&M costs, labor, and energy requirements. However, the
peak hourly flow must be used for hydraulic sizing of pumps. Therefore, a
diurnal peaking factor must be determined and applied to the design average
flow to provide a peak hourly design flow.
Figure 4-2 presents wastewater flow rate curves for the Jackson Pike and
Southerly plants compiled from September 1985 dry weather/no bypass days. The
diurnal peaking factor was determined for the Jackson Pike and Southerly WWTPs
through an analysis of hourly wastewater flows for February and September
1985. These two months represent minimum and maximum water consumption,
respectively for 1985. The 1985 months were chosen since the existing average
flow occurred in May of 1985. Diurnal peaking factors were calculated by
dividing the maximum hourly flow by the average hourly flow for each dry
weather/no bypass day during February and September. These values are listed
in Tables 4-4 and 4-5.
The maximum diurnal peaking factor seen at Jackson Pike during this
period was 1.40, and at Southerly it was 1.51. Jackson Pike's value of 1.40
occurred several times and was selected as the diurnal peaking factor for
Jackson Pike. Southerly's maximum value of 1.51, however, was considered to
be excessive. It occurred, only once, on September 21 when the average hourly
flow was at a low of 45 MGD. The next peaking factor in the series was 1.37
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TABLE 4-4. HOURLY FLOW DATA SOUTHERLY WWTP
Average Hourly Peak Hourly
Date
2/4/85
2/8/85
2/9/85
2/16/85
2/17/85
2/18/85
2/19/85
2/20/85
2/26/85
2/27/85
2/28/85
9/1/85
9/2/85
9/3/85
9/4/85
9/5/85
9/6/85
9/7/85
9/8/85
9/9/85
9/10/85
9/11/85
9/12/85
9/13/85
9/14/85
9/15/85
9/16/85
9/17/85
9/18/85
9/19/85
9/20/85
9/21/85
9/22/85
9/28/85
9/29/85
* Peaking
Flow (MGD)
56.2
55.8
54.6
69.5
67.6
69.0
71.2
75.0
87.1
81.3
82.5
48.8
49.4
53.1
52.2
52.5
50.4
51.3
49.0
50.7
53.2
53.9
51.9
40.1
54.0
49.8
52.0
51.2
52.2
51.8
49.9
45.0
51.3
51.3
50.3
Factor = Peak
Flow (MGD)
58.0
63.0
65.0
83.0
79.0
78.0
78.0
81.0
97.0
90.0
85.0
56.0
62.0
62.0
59.0
57.0
57.0
60.0
56.0
54.0
57.0
61.0
59.0
55.0
64.0
57.0
64.0
55.0
58.0
57.0
58.0
68.0
68.0
62.0
59.0
Hourly Flow
Peaking*
Factor
1.03
1.13
1.19
1.19
1.17
1.13
1.10
1.08
1.11
1.11
1.03
1.14
1.26
1.17
1.13
1.09
1.13
1.17
1.14
1.07
1.07
1.13
1.14
1.37
1.19
1.14
1.23
1.07
1.11
1.10
1.16
1.51
1.33
1.21
1.17
Weather
Condition
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
Average Hourly Flow
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TABLE 4-5. HOURLY FLOW DATA JACKSON PIKE WWTP
Date
2/4/85
2/8/85
2/9/85
2/16/85
2/17/85
2/18/85
2/19/85
2/20/85
2/26/85
2/27/85
2/28/85
9/1/85
9/2/85
9/3/85
9/4/85
9/5/85
9/6/85
9/7/85
9/8/85
9/9/85
9/10/85
9/11/85
9/12/85
9/13/85
9/14/85
9/16/85
9/17/85
9/18/85
9/19/85
9/20/85
9/21/85
9/22/85
9/28/85
9/29/85
* Peaking
Average Hourly
Flow (MGD)
76.0
73.0
69.0
91.0
87.0
92.0
91.0
92.0
98.0
95.0
99.0
69.3
72.0
76.9
81.0
81.3
79.5
75.6
72.1
78.7
79.0
76.0
71.7
73.7
69.3
72.4
72.3
73.4
72.9
72.6
70.0
67.0
70.6
68.5
Factor = Peak Hourly
Peak Hourly
Flow (MGD)
94.0
96.0
89.0
102.0
106.0
102.0
98.0
103.0
106.0
104.0
102.0
86.0
89.0
104.0
96.0
95.0
94.0
94.0
92.0
96.0
92.0
90.0
85.0
86.9
96.8
88.0
96.0
92.0
88.8
89.0
90.0
94.0
99.0
83.0
Flow
Peaking*
Factor
1.24
1.32
1.29
1.12
1.22
1.11
1.08
1.12
1.08
1.09
1.03
1.24
1.24
1.35
1.19
1.17
1.18
1.24
1.28
1.22
1.16
1.18
1.19
1.18
1.40
1.22
1.33
1.25
1.22
1.23
1.29
1.40
1.40
1.21
Weather
Condition
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
DRY
Average Hourly Flow
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which is more representative of the maximum diurnal peaking factor seen at the
Southerly plant. Thus, 1.4 was chosen as a representative diurnal peaking
factor for both plants.
4.1.3 Peak Process Flow
A peak process flow must be developed for use in sizing the various wet
stream processes. This flow establishes the maximum process capability of the
wet stream treatment facilities. Flows greater than the peak process flow
will cause the treatment facilities to operate beyond their intended design
criteria. Sustained operation above the peak process flow may result in a
violation of permit limits.
The peak process flow is most reliably established through an analysis of
existing flow. This approach was not possible in the Columbus system due to
the nature of the flow record. As discussed in Section 2, the flow records
for the two Columbus plants provided limited information regarding the amount
of sewage bypassed. As a result a reliable record of the total flow arriving
is not available. Furthermore, peak wastewater flows normally include some
combined sewage. A combined sewage overflow study, which will define a CSO
control strategy, is currently being prepared by the city. The impact of the
CSO recommendation on the wastewater treatment facilities will be evaluated at
the conclusion of that study.
In the 1979 EIS, the following empirical formula was utilized to develop
a peak process flow, due to the absence of a comprehensive flow record.
Peak Process Flow = 1.95 (Average Daily Flow) °'95
Lacking flow information which would substantiate a peak process flow,
the 1979 EIS formula provides a reasonable method for developing a peak
process flow. Based on the 2008 average design flow of 154 MGD, the formula
yields a peak process flow of 233 MGD. This corresponds to a process peaking
factor of 1.5.
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The 1.5 process peaking factor was evaluated relative to the 1986
available flow data to assess the extent of its range. The 1986 flow record
includes flows treated at Jackson Pike and Southerly and also the flows which
are bypassed at Southerly. The flow record does not include flows which were
bypassed at Whittier Street or any other combined sewer overflows. The 1986
average flow of the two plants was 145 MGD. Applying the 1.5 process peaking
factor to this average flow yields a peak process flow of 218 MGD. Comparing
this flow with the 1986 record indicated that the daily flow rate of 218 MGD
was exceeded only nine days during the year or approximately 2.5 percent of
the time. In light of these few exceedances, the 1.5 process peaking factor
established by the 1979 EIS provides a reasonable approach to establish a peak
process flow.
4.1.4 Wet Weather Flow
The maximum monitored wet weather flow as determined from 1986 records
and discussed in Section 3.4 is 309.52 MGD. This flow occurred on March 14.
It includes 95.57 MGD for the Jackson Pike WWTP and 213.95 MGD for the
Southerly WWTP. The Southerly flow can be broken down into 78.05 MGD
receiving complete treatment, 30.30 MGD receiving primary treatment and
chlorination, and 105.60 being bypassed directly to the Scioto River. Note
that this maximum wet weather flow only includes flow that arrives at the
treatment plants. Any flow being bypassed at the various points of combined
sewer overflow is not included.
4.2 WASTEWATER LOADS
Monthly average influent TSS (total suspended solids) and BOD (biochemical
oxygen demand) loads were determined for all weather conditions. These loads
are presented in Tables 4-6 and 4-7.
The sampling point at Jackson Pike for TSS and BOD concentrations is
located at the grit chambers on the O.S.I.S. Therefore, the samples do not
represent the flow from the Big Run Interceptor. The O.S.I.S. carries in
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TABLE 4-6. 1985 AVERAGE BOD LOADS (Ib/day)
Month
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
OcC.
Nov.
Dec.
ANNUAL
Jackson Pike
BOD
118,466
109,094
104,532
97,918
97,831
109,632
94,384
93,591
88,619
104,161
96,483
92,466
100,702
Southerly
BOD
91,187
82,506
82,819
87,777
89,108
85,513
84,649
86,073
98,992
105,446
76,140
76,992
87,258
Total
BOD
209,653
191,600
187,351
185,695
186,939
195,145
179,033
179,664
187,611
209,607
172,623
169,458
187,960
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TABLE 4-7. 1985 and 1986 MONTHLY AVERAGE TSS LOADS (Ib/day)
Jackson Pike
Southerly
Total
Month
Jan.
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
ANNUAL
1985 TSS
120,331
121,223
136,509
110,170
136,038
158,045
153,317
126,033
114,192
121,086
148,916
105,969
129,347
1986 TSS
115,923
120,583
129,050
124,532
133,613
139,516
113,282
108,853
129,688
139,653
112,099
104,965
122,665
1985 TSS
99,391
108,739
107,085
106,911
108,516
99,145
105,571
91,308
95,424
93,693
99,165
97,948
101,042
1986 TSS
87,633
91,508
94,313
92,109
89,700
95,078
93,421
100,996
101,437
100,830
88,952
86,313
93,535
1985 TSS
219,722
229,962
243,594
217,081
244,554
257,190
258,888
217,341
209,616
214,779
248,081
203,917
230,389
1986 TSS
203,556
212,091
223,363
216,641
223,313
234,594
206,703
209,849
231,125
240,483
201,051
191,278
216,200
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approximately 65 to 70 percent of the flow at Jackson Pike. Plant staff
believe that the flow arriving through the O.S.I.S. contains the majority of
the industrial flow in the Jackson Pike service area. Samples taken from the
O.S.I.S. have always been used to establish waste loads for the total flow to
Jackson Pike. The Southerly flow is sampled between the screens and the grit
chambers. Thus, the samples are representative of 100 percent of the flow
entering the Southerly plant.
Only 1985 data were used to determine existing BOD loads because there
were insufficient data available for 1986. There were only 304 days of
reported BOD values for Jackson Pike in 1986. There were 341 days of data for
Jackson Pike in 1985. Southerly reported BOD values on 362 days in 1986 and
364 days in 1985.
The 1985 annual average BOD load for Jackson Pike, as presented in Table
4-6, is 100,702 Ib/day. The maximum monthly average load is 118,466 Ib/day,
and it occurred in January. The ratio of maximum monthly average to the
annual average results in a peaking factor of 1.2.
The 1985 annual average BOD load for Southerly, as shown in Table 4-6, is
87,258 Ib/day. The maximum monthly average load, which occurred in October,
is 105,446 Ib/day. The peaking factor, as determined by dividing the maximum
monthly average by the annual average, is 1.2.
1985 and 1986 data were used to establish TSS loads for Jackson Pike and
Southerly. Jackson Pike had 365 and 363 days of TSS data for 1985 and 1986,
respectively. There were 364 days of TSS data reported for Southerly for both
years.
The average TSS load was obtained by computing the average of the annual
averages for 1985 and 1986. The Southerly 1985 and 1986 average is 97,289
Ib/day; and Jackson Pike is 126,006 Ib/day. Peaking factors were established
for each year in the same manner as was used for BOD loads. The peaking
factors for Jackson Pike are 1.2 and 1.1 for 1985 and 1986, respectively. The
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higher value of 1.2 was chosen as Che Jackson Pike TSS peaking factor. The
Southerly TSS peaking factors are 1.1 for both 1985 and 1986. Table 4-8
summarizes the 1985 and 1986 average and peak BOD and TSS loads.
TABLE 4-8. 1985 AND 1986 BOD AND TSS LOADS
BOD LOADS
• Average (Ib/day)
(lb/capita day)
• Peak (Ib/day)
• Peaking Factor
TSS LOADS
• Average (Ib/day)
(lb/capita day)
• Peak (Ib/day)
• Peaking Factor
Jackson Pike Southerly
100,702
0.206
118,466
1.2
POPULATION
126,006
0.258
151,207
1.2
489,000
87,258
0.229
105,446
1.2
97,289
0.255
107,018
1.1
381,000
Total
187,960
0.216
223,912
1.1
223,295
0.257
251,925
1.1
870,000
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A summary of the 1985 population figures and historic wastewater flows
and loads is presented in Table 4-9. These quantities were used as a basis
for projecting flows and loads to the design year.
TABLE 4-9. 1985 FLOWS AND LOADS
Jackson Pike Southerly TOTAL
Total Flow
Ave. (MGD) 84 61 145
• Infiltration 40.1 22.1 62.2
• Industrial 9.0 6.9 15.9
• Commercial 4.5 3.2 7.7
• Domestic 30.4 28.8 59.2
BOD Load (Ib/day) 118,500 105,400 223,900
TSS Load (Ib/day) 151,200 107,000 258,200
Population 489,000 381,000 870,000
4.3 PROJECTED FLOWS AND LOADS
This next section presents flows and loads projected to the 2008 design
year.
Table 4-10 presents the flows of Table 4—9 in per capita/connection
form. These data further reinforce the figures presented in Table 4-9 since
they represent reasonable values in agreement with the literature.
Holding infiltration and industrial flows constant and using the existing
per capita commercial and domestic flows (Table 4-10) and the population
projections for 1988 and 2008, wastewater flows were projected for 1988 and
2008.
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— TABLE 4-10. 1985 PER CAPITA/CONNECTION FLOWS
Jackson Pike Southerly TOTAL
Per Capita
Domestic Wastewater Flow (gpcd) 62.2 75.6 68.1
• Per Capita
Commercial Wastewater Flow (gpcd) 9.2 8.4 8.9
• Per Capita
Industrial Wastewater Flow (gpcd) 18.4 18.1 18.2
I Per Capita
Industrial, Commercial, and
Domestic Wastewater Flow (gpcd) 89.8 102.1 95.2
• Per Capita
Infiltration (gpcd) . 82 58 72
Per Connection
Commercial Wastewater Flows'
(gal/connection day) ND ND 816.7
• Per Connection
™ Industrial Wastewater Flows
(gal/connection day) ND ND 62,109
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1985 Per Capita
Water Pumped
Industrial, Commercial, and
Domestic (gpcd) ND ND 139.1
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1985 (Industrial, Commercial, and
• Domestic) Water Pumped to Wastewater
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Discharge Factor ND ND .976
SOURCE: City of Columbus, Division of Sewerage and Drainage, December 1986
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There was insufficient information available to disaggregate the existing
industrial loads and the expected future industrial loads from the total.
Therefore, the existing total per capita BOD and TSS loads from Table 4-8 were
multiplied by the population projections and the respective peaking factors to
obtain the 1988 and 2008 projected loads. In doing so, growth of industrial
contributions is proportional to residential growth.
Table 4-11 presents the 1988 projected population, flows, and loads for
each plant; and Table 4-12 presents the projected design average flows and
loads for the 2008 design year.
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1
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TABLE 4-11. 1988
Jackson Pike
Total Flow
Ave. (MGD) 84.8
• Infiltration 40.1
• Industrial 9.0
• Commercial 4.6
• Domestic 31.1
BOD Load (Ib/day) 123,400
TSS Load (Ib/day) 154,500
Population 499,000
TABLE 4-12. 2008
Jackson Pike
Total Flow
Ave. (MGD) 87.9
• Infiltration 40.1
• Industrial 9.0
• Commercial 5.0
• Domestic 33.8
BOD Load (Ib/day) 134,600
TSS load (Ib/day) 168,600
Population 544,600
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PROJECTIONS
Southerly
61.7
22.1
6.9
3.3
29.4
106,900
109,100
389,000
PROJECTIONS
Southerly
66.0
22.1
6.9
3.7
33.3
121,300
123,800
441,400
TOTAL
146.5
62.2
15.9
7.9
60.5
230,300
263,600
888,000
TOTAL
153.9
62.2
15.9
8.7
67.1
255,900
292,400
986,000
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5. FACILITY PLAN METHODOLOGY
The following sections summarize the design wastewater flows and loads
proposed in the facility plan and the methodology used in their development.
The Revised Facility Plan Update (RFPU) and the General Engineering Report and
Basis of Design (GERBOD) were used to prepare this discussion. The following
sections include:
• Dry Weather Wastewater Flows
• Design Average Daily Flows
• Design Loads
• Industrial Flows and Loads
• Projected Design Flows and Loads
The facility plan developed existing dry weather wastewater flows to
approximate a low groundwater condition. These flows were projected to the
2015 design year. Then average daily flows were developed to approximate
average infiltration under a high groundwater condition and these flows were
projected to the 2015 design year. The 2015 average daily flows approxi-
mating average infiltration under a high groundwater condition were selected
as the design average flows for use in alternative development in the facility
plan.
Existing waste loads were determined and projected to the 2015 design
year. Two scenarios were developed for future additional flows and loads from
undocumented industrial growth. However, since neither of these scenarios was
included in the design average flows and loads, it appears that a decision was
made not to plan for future undocumented industrial growth. The last section
summarizes the facility plan's selected design wastewater flows and loads.
5.1 DRY WEATHER WASTEWATER FLOWS
The Revised Facility Plan Update developed dry weather flows to
approximate low infiltration under low groundwater conditions. Monthly
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Operating Reports (MORs) were used to determine dry weather wastewater flows
through three different methods.
• An average daily flow was derived for the 1984 dry months (July and
August).
• A 50th percentile flow was determined from 40 randomly selected dry
weather days between 1982 and 1984.
• An average daily flow was derived for the dry months of 1979
through 1984.
The GERBOD states that flows of 74 MGD for Jackson Pike and 53 MGD for
Southerly were determined from the first method listed above using 1984 dry
months. The report states that the flows developed by the other two methods
closely approximate these flows, but a direct comparison is not provided.
The 1983 population for each WWTP service area was selected as the
population value to be used for calculation of gallons per capita per day
(gpcd) flow factors. The 1983 Southerly population was determined to be
356,901 and the Jackson Pike population was determined to be 470,979.
Calculated gpcd flow factors are 149 gpcd for Southerly and 157 gpcd for
Jackson Pike which results in a system-wide average of 153 gpcd. By
comparison, a system-wide average of 152 gpcd was calculated in the Original
Facility Plan based upon 1975 flow data.
Utilizing population projections developed in the Revised Facility Plan
Update (presented in Table 5-1) and the gpcd flow factors discussed above, dry
weather flows were projected for each plant for the years 1988, 2000, and
2015. Table 5-2 presents these flows.
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TABLE 5-1. FACILITY PLAN POPULATION PROJECTIONS
Service Area Year
Jackson Pike
Southerly
TOTAL
1988
487,644
382,783
870,427
2000
531,366
420,495
951,861
2015
573,052
459,992
1,033,044
SOURCE: Revised Facility Plan Update - URS Dal ton 1985
TABLE 5-2. PROJECTED DRY WEATHER FLOWS (MGD)
Service Area Year
1988 2000 2015
Jackson Pike 77 83 90
Southerly 58 63 69
TOTAL 135 146 159
SOURCE: Revised Facility Plan Update - URS Dalton 1985
5.2 DESIGN AVERAGE DAILY FLOWS
The Revised Facility Plan Update developed design average daily flows to
approximate average infiltration under high groundwater conditions. Flow
values were obtained from Monthly Operating Reports (MOR). Forty-five days
were randomly selected from the years 1982 through 1985 based on the following
criteria:
• .Weekdays only
• No significant rainfall on the sample day
• No significant rainfall for 24 hours prior to the sample day
• No reported bypassing
The 50th percentile flow values were derived from probability plots
for each WWTP. The Jackson Pike flow was determined to be 84 MGD, and the
Southerly flow was determined to be 59 MGD.
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The WWTP service area population figures for 1984 of 475,909 for Jackson
Pike and 363,097 for Southerly were used to convert the above flows to gpcd
flow factors. Jackson Pike was calculated at 177 gpcd and Southerly was
calculated at 162 gpcd. Table 5-3 shows the breakdown of the flow factors as
presented in the RFPU.
TABLE 5-3. DESIGN AVERAGE FLOW FACTORS (gpcd)
Jackson Pike Southerly Total
Flow Component Service Area Service Area Service Area
Domestic
Industrial
Infiltration
Total 177 162 171
Source: Revised Facility Plan Update - URS Dalton 1985
Using population projections (Table 5-1) and total gpcd flow factors
developed for each WWTP, design flows were projected for the years 1988, 2000,
and 2015. These flows are shown in Table 5-4.
TABLE 5-4. DESIGN AVERAGE FLOWS (MGD)
Year
80
15
82
80
24
58
80
19
72
Service Area
Jackson Pike
Southerly
TOTAL
1988
86
63
149
2000'
94
68
162
2015
101
75
176
SOURCE: Revised Facility Plan Update - URS Dalton 1985
5.3 DESIGN LOADS
Existing wasteloads were determined by randomly selecting 80 days from
MORs for each WWTP based on the following criteria:
• 40 days during the low infiltration season - July, August, September
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• 40 days during the low temperature season - December, January,
February
• Years 1982, 1983, 1984
• No significant rainfall on the selected day.
• No significant rain for 24 hours prior to the selected day
• No bypassing
• Weekdays only
The parameters selected for analysis were BODc, TKN, phosphorus,
suspended solids, and flow.
Probability plots were constructed from these calculated loads for both
the low infiltration season and the low temperature season. The 80th
percentile loads were chosen from the low infiltration plots. These loads
were used in calculating projected loads for 1988, 2000, and 2015.
Adjustments were made for the Anheuser-Busch Brewery. It was assumed that the
existing loads and flow from the brewery are the following:
• BOD = 35,260 Ib/day
• SS 13,400 Ib/day
• Flow =3.13 MGD
For future projections it was assumed that the brewery would increase
to its maximum monthly average BODc limit of 45,000 Ib/day.
Table 5-5 presents the Revised Facility Plan Update's design wasteloads
for the Jackson Pike and Southerly WWTP.
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TABLE 5-5. DESIGN WASTELOADS (Ib/day)
Jackson Pike
Design
Year
1988
2000
2015
1988
2000
2015
BOD5
127,150
137,060
148,620
117,060
123,730
131,740
Suspended
Solids
145,780
157,130
170,390
180,020
116,450
126,550
TKN
16,700
18,000
19,520
14,570
15,760
17,260
Total
Phosphorus
5,459
5,884
6,380
4,595
4,991
5,467
Southerly
SOURCE: Revised Facility Plan Update - URS Dalton 1985
5.4 INDUSTRIAL FLOWS AND LOADS
The Revised Facility Plan Update presented tables which included
additional flow and loading allowances for future, undocumented industrial
growth. This growth was only assumed to affect the Southerly plant. No
reason was provided for this assumption. Flow projections for both dry
weather and design average flow were increased by 2 MGD and 4 MGD after 1988
to account for the possibility of undocumented growth in the industrial
sector. Table 5-6 presents dry weather flow projections with the additional
flow allowances of 2.0 MGD and 4.0 MGD for undocumented industrial growth.
Table 5-7 presents design average flow projections with the same flow
allowances.
TABLE 5-6. DRY WEATHER FLOW PROJECTIONS FOR UNDOCUMENTED INDUSTRIAL GROWTH
(2 MGD/4 MGD FLOW ALLOWANCES)
Service Area
Jackson Pike
Southerly
TOTAL
SOURCE: Revised Facility Plan Update - URS Dalton 1985
Year
1988
77/77
58/58
135/135
2000
83/83
65/67
148/150
2015
90/90
71/73
161/163
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TABLE 5-7. DESIGN AVERAGE FLOW PROJECTIONS FOR UNDOCUMENTED INDUSTRIAL GROWTH
(2 MGD/4 MGD FLOW ALLOWANCES)
Year
Service Area 1988 2000 2015
Jackson Pike 86/86 94/94 101/101
Southerly 63/63 70/72 77/79
TOTAL 149/149 164/166 178/180
SOURCE: Revised Facility Plan Update - URS Dalton 1985
The increase in industrial flow could also increase the wasteload
projection. Therefore, the facility planners also revised their wasteload
projections to reflect the 2/4 MGD flow increases. Since the industrial flow
increase was only added to the Southerly WWTP, the increase in wasteloads will
only affect the Southerly plant. Table 5-8 presents these revised wasteload
projections for Southerly.
TABLE 5-8. DESIGN WASTELOAD PROJECTIONS (Ib/day)
ADJUSTED FOR UNDOCUMENTED INDUSTRIAL GROWTH
SOUTHERLY WWTP
Design
Year
2 MGD Allowance
1988
2000
2015
4 MGD Allowance 1988
2000
2015
BOD,;
117,060
138,730
146,740
117,060
163,730
171,740
Suspended
Solids
108,820
122,170
132,230
108,020
131,610
141,710
TKN
14,510
16,510
18,010
14,510
17,760
19,260
Total
Phosphorus
4,595
5,066
5,542
4,595
5,191
5,667
SOURCE: Revised Facility Plan Update - URS Dalton 1985
The flows and loads which included an allowance for undocumented
industrial growth were not used as a basis for alternative development, which
assumes no industrial growth during the planning period.
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5.5 PROJECTED DESIGN FLOWS AND LOADS
This section summarizes the facility plan's projected design flows and
loads.
5.5.1 Design Flows
The Jackson Pike and Southerly projected 2015 design average daily flows
of 101 MGD and 75 MGD, respectively, were chosen by the facility plan as the
basis for development. These flows were presented in Section 5.2.
Since the Revised Facility Plan Update chose the one-plant alternative,
the design flows for Jackson Pike and Southerly were combined resulting in an
average daily design flow of 176 MGD to be treated at Southerly. Peak process
design was then calculated as 300 MGD by multiplying the design average flow
by a peaking factor of 1.7. The peak process flow of 300 MGD is used to size
the wet stream treatment facilities. There is no supportable information in
the facility plan on how the peaking factor was derived. There is reference
to the fact that anything greater than 1.7 would adversely affect process
efficiency under average flow conditions. In subsequent correspondence and a
clarifying telephone conversation with the city's consultant, it was
determined that 1.7 was based on a hydraulic constriction between the existing
primary clarifiers and aeration basins at the Southerly WWTP. The consultant
indicated that each existing train is limited to an average to peak flow ratio
of 44 MGD to 75 MGD. The 44 MGD average flow is based on mass loading to the
aeration basins, and the 75 MGD peak flow is based on the hydraulic capacity
of the existing conduits between the primary clarifiers and the aeration
tanks. In light of the fact that the CSO study is incomplete and that
analyses of wet weather data was limited, the 1.7 peaking factor was
considered appropriate by the city and their consultant.
An additional 130 MGD for CSO control is added on to the peak process
flow of 300 MGD and this total flow of 430 MGD is considered as the peak
hydraulic flow. There are conflicting statements in the facility plan
regarding which treatment processes will be sized for 430 MGD. In Chapter 2,
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it is stated that flows between 300 MGD and 430 MGD will be processed through
primary settling and chlorination. In Chapter 12, it appears that only the
influent pumps and bar racks and screens are being sized for 430 MGD.
5.5.2 Design Loads
Section 5.3 presented design loads determined in the facility plan
through analysis of Jackson Pike and Southerly plant records. In addition to
these loads, the facility plan presents loads contributed by the additional
flows conveyed to the plant during peak hydraulic flow conditions. These
additional flows are considered to be diverted from Whittier Street.
Table 5-9 presents the design loadings for the year 2015 including the loads
from Whittier Street flows.
TABLE 5-9. DESIGN LOADINGS (Ib/day)
Parameter Southerly Jackson Pike Whittier St. Total
BODr 131,740 148,620 10,000 290,360
TSS 126,550 170,390 20,000 316,940
TKN 17,260 19,520 1,300 38,080
P 5,467 6,380 400 12,247
SOURCE: Revised Facility Plan Update - URS Dalton 1985
/
Since the Revised Facility Plan Update chose the one-plant alternative,
the loads listed in the Total column in the previous table were used as the
basis for development of alternatives.
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6. COMPARISON OF BRIEFING PAPER AND FACILITY PLAN FLOWS AND LOADS
This section summarizes the design flows and loads developed in the
facility plan and those developed by this briefing paper. Table 6-1 provides
a comparison between the two.
TABLE 6-1. COMPARISON OF DESIGN FLOWS AND LOADS
Facility Plan
Briefing Paper
149
2015
176
1.7
300
290,360
316,940
147
2008
154
1.5
231
255,900
292,400
1988 Projected Average Flow (MGD)
Design Year
Design Average Flow (MGD)
Process Peaking Factor
Peak Process Flow (MGD)
Design BOD Load (Ib/day)
Design TSS Load (Ib/day)
The 1988 projected average flows are very close, being 149 MGD in the
facility plan and 147 for this briefing paper. The projected design average
flows of 176 MGD for the facility plan and 154 MGD for this briefing paper
vary by 22 MGD (14 percent) due to different design years that result in a
difference in population projections. The facility plan flows are based on
the year 2015 and the briefing paper flows are based on a 2008 design year.
For purposes of comparison, the facility plan design, average flow was brought
back to the year 2008. Using the 2008 population projections developed for
the EIS and the gpcd flow figures used in the facility plan, the facility plan
flows for 2008, presented in Table 6-2, are 96 MGD for Jackson Pike and 72 MGD
for Southerly. This total flow of 168 MGD for both plants is 14 MGD (9
percent) higher than the briefing paper flow of 154 MGD.
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TABLE 6-2. FACILITY PLAN POPULATION AND FLOW PROJECTIONS
Flow Values (gpcd)
1988
• Population
• Flow (MGD)
2000
2015
Population
Flow (MGD)
2008
• Population*
• Flow (MGD)**
Population
Flow (MGD)
Jackson Pike
177
487,644
86
531,366
94
544,600
96
573,052
101
Southerly
162
382,783
63
420,495
68
441,400
72
459,992
75
TOTAL
171
870,427
149
951,861
162
986,000
168
1,033,044
176
Source: Revised Facility Plan Update - 1985
*EIS population projections.
**Developed for comparison with briefing paper 2008 design flow.
Thus, even if the design years are the same and the population projec-
tions are the same, the design flows still differ slightly. This difference
is because the flow projections made in the briefing paper were developed by
holding the infiltration and industrial portions of the flow constant and
increasing only the commercial and domestic flows proportional to the popula-
tion increase, whereas the flows in the facility plan were developed by
increasing all of the flow, including infiltration and industrial,
proportional to the population increase. Projected increases in infiltration
do not appear justified if the population increase is located within the
existing service area. The facility plan does not document why an increase in
infiltration should be planned for. Projected industrial increases should be
based on documented industrial growth by existing industries and/or policy
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decisions by the municipality Co plan for future undocumented growth.
Furthermore, such industrial growth should be an identifiable part of the
total design loads since capital cost recovery for the added capacity must be
addressed.
The projected peak process flows are 231 MGD and 300 MGD for the briefing
paper and facility plan, respectively. These flows differ significantly due
to differences in design average flows and different peaking factors. The
reasons for the different design average flows were discussed in the previous
paragraphs. The peaking factor is 1.5 for the briefing paper and 1.7 for the
facility plan. The 1.5 peaking factor for the briefing papers is consistent
with the peaking factor used in the original EIS. The facility plan's peaking
factor of 1.7 is based on the maximum hydraulic capability of the conduits
between the primary clarifiers and aeration basins in the existing trains at
the Southerly WWTP.
A breakdown of the briefing paper and facility plan projected BOD and TSS
loads is presented in Table 6-3. The differences in loads are partially due
to differences in design years and also due to the inclusion of loads from
Whittier Street. For comparison purposes, Table 6-4 presents the facility
plan loads brought back to 2008 without the Whittier Street loads. These
loads were decreased to the year 2008 using EIS population projections and
load factors developed in Section 4.2 of this document. In comparing the
briefing paper loads to the 2008 facility plan loads, it was found that the
loads are within 5 percent of each other. Therefore, the 2008 facility plan
loads will be used as the basis for further EIS evaluations.
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TABLE 6-3. COMPARISON OF FACILITY PLAN AND BRIEFING PAPER DESIGN LOADS
Design Year
Jackson Pike
• BOD (Ib/day)
• TSS (Ib/day)
Southerly
• BOD (Ib/day)
• TSS (Ib/day)
Whittier Street
• BOD (Ib/day)
• TSS (Ib/day)
TOTAL
BOD (Ib/day)
• TSS (Ib/day)
Facility Plan
2015
148,620
170,390
131,740
126,550
10,000
20,000
290,360
319,940
Briefing Paper
2008
134,600
168,600
121,300
123,800
255,900
292,400
TABLE 6-4. 2008 PROJECTED LOADS
Jackson Pike
• BOD (Ib/day)
• TSS (Ib/day)
Southerly
• BOD (Ib/day)
• TSS (Ib/day)
Total
• BOD (Ib/day)
• TSS (Ib/day)
Facility Plan
141,600
161,600
126,600
121,300
268,200
282,900
Percent Difference
EIS From Facility Plan
134,600 -4.9
168,600 +4.3
121,300 -4.2
123,800 +2.1
255,900 -4.5
292,400 +3.2
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Summary
Table 6-5 summarizes Che 2008 flows and loads which will be used as a
basis for further EIS analysis. The 2008 average flows developed in this
briefing paper will be utilized. They were developed based on 1985 and 1986
plant records, industrial flow data from the 1983 Industrial Pretreatment
Report, and the facility plan infiltration values. A process peaking factor
of 1.5 is applied to this average flow to obtain the peak process flow. The
facility plan BOD and TSS loads brought back to 2008, without the Whittier
Street loads, will be utilized as the design loads. Further documentation is
required and has been requested to verify the industrial flows and
infiltration value.
TABLE 6-5. 2008 PROPOSED EIS FLOWS AND LOADS
Jackson Pike Southerly Total
Average Flow (MGD) 88 66 154
Peak Process Flow (MGD) 132 99 231
BOD Load (Ib/day) 141,600 126,600 268,200
TSS Load (Ib/day) 161,600 121,300 282,900
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APPENDIX B
BRIEFING PAPER NO. 2
SOLIDS HANDLING ALTERNATIVES
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• BRIEFING PAPER NO. 2
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SOLIDS HANDLING ALTERNATIVES
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• Supplemental Environmental Impact Statement
- USEPA Contract No. 68-04-5035, D.O. No. 40
I Columbus Ohio Waste-water Treatment Facilities
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• Prepared By.
I SCIENCE APPLICATIONS INTERNATIONAL CORPORATION
| TRIAD ENGINEERING INCORPORATED
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SOLIDS HANDLING ALTERNATIVES
1. EXISTING SLUDGE MANAGEMENT SYSTEMS
1.1 Jackson Pike
1.2 Southerly
2. DEVELOPMENT OF SLUDGE MANAGEMENT ALTERNATIVES
2.1 Jackson Pike Sludge Management Alternatives (Two-Plant Scenario)
2.1.1 Jackson Pike Sludge Management Alternative JP-A
2.1.2 Jackson Pike Sludge Management Alternative JP-B
2.1.3 Jackson Pike Sludge Management Alternative JP-C
2.2 Southerly Sludge Management Alternatives (Two-Plant Scenario)
2.2.1 Southerly Sludge Management Alternative SO-A
2.2.2 Southerly Sludge Management Alternative SO-B
2.2.3 Southerly Sludge Management Alternative SO-C
2.2.4 Southerly Sludge Management Alternative SO-D
2.2.5 Southerly Sludge Management Alternative SO-E
2.2.6 Southerly Sludge Management Alternative SO-F
2.3 Southerly Sludge Management Alternatives (One-Plant Scenario)
3. EVALUATION OF SLUDGE MANAGEMENT ALTERNATIVES
3.1 Cost Effectiveness of Sludge Management Alternatives
3.2 Sludge Dewatering
3.3 Planned System Redundancy
3.4 Ultimate Disposal Plan
3.4.1 Distribution and Marketing of Composted Sludge
3.4.2 Land Application of Digested, Dewatered Sludge
3.4.3 Landfilling of Incinerated Dewatered Sludge
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INTRODUCTION
Under Che direction of USEPA, a series of briefing papers are being
prepared addressing key issues in Che development of the Supplemental
Environmental Impact Statement for the Columbus, Ohio, Wastewater Treatment
Facilities. The briefing papers form the basis of discussions between Triad
Engineering and USEPA to resolve these key issues. The following paragraphs
present the background of the facility planning process, a description of the
briefing papers, and Che purpose of this paper on solids handling alterna-
tives.
FACILITY PLANNING PROCESS
At the time this paper was prepared (March-August 1987) Che city of
Columbus was proceeding to implement improvemenCs aC Che Jackson Pike and
Southerly WasCewater TreaCmenC Plants to comply with more stringent effluent
standards which must be met by July 1, 1988. These improvements were based
on the consolidacion of wasCewaCer treatment operations at Che SouCherly
plant. This one-plant alternative is a change from the two-plant operation
proposed by Che cicy in Che 1970's and evaluated in the 1979 EIS.
The development and documentation of a wastewater treatment process and
sludge management alternatives for the Columbus metropolitan area has been an
extended and iterative process. The design and construction of various
system componenCs have progressed, because of Che 1988 deadline, while
planning issues continue Co be resolved. As a resulc, numerous documenCs have
been prepared which occasionally revise a previously esCablished course of
direction.
The concurrent resolution of planning issues and implementation of
various project components has made preparation of the EIS more difficult
because final facilicy plan recommendacions are noC available in a single
document.
B-l
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BRIEFING PAPERS
To facilitate preparation of the EIS, a series of briefing papers are
being developed. The purpose of the briefing papers is to allow USEPA to
review the work of the EIS consultant and to identify supplemental information
necessary for the preparation of the EIS. Six briefing papers are being
prepared as follows:
• Flows and Loads
• Sludge Management
• CSO
• Process Selection
• One Plant vs. Two Plant (Alternative Analysis)
• O&M and Capital Costs
The specific focus of each briefing paper will be different. However,
the general scope of the papers will adhere to the following format:
• Existing conditions will be documented.
• Evaluations, conclusions, and recommendations of the facilities
planning process will be reviewed using available documentation.
• Where appropriate, an independent evaluation of the future situation
and viable alternatives will be prepared.
• The facility plan and EIS briefing paper conclusions will be compared.
The briefing paper process is intended to:
• Prompt the resolution of any data deficiencies.
• Clearly establish and define existing and future conditions.
• Identify the final recommended plan which the city desires to implement.
• Provide a data base of sufficient detail to allow preparation of the
draft EIS.
B-2
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SLUDGE MANAGEMENT ALTERNATIVES
This briefing paper reviews Che facilities planning process and
subsequent efforts by the city relative to the development and adoption of a
sludge management alternative. The briefing paper is divided into four
sections as follows:
Section 1 - Existing Sludge Management System.
Section 1 defines the current sludge processing and disposal practices of
the Jackson Pike and Southerly plants. It establishes a foundation from
which potentially viable sludge management alternatives can be
identified.
Section 2 - Development of Sludge Management Alternatives
In Section 2 potentially viable sludge management alternatives are
identified and developed sufficiently to allow a comparative evaluation.
Section 3 - Evaluation of Sludge Management Alternatives
Section 3 evaluates the sludge management alternatives that were
developed. The alternatives are evaluated with respect to the analysis
of the briefing paper and in light of the recommendations of the
facilities planning process and subsequent planning and preliminary
design documents.
Section 4 - Planning Issues to be Resolved
In Section 4 the issues that developed through this analysis are
highlighted to facilitate discussion and resolution.
The primary sources of information utilized in preparing this briefing paper
included:
• Revised Facilities Plan Update, September 30, 1985
• General Engineering Report and Basis of Design, January 1, 1986
• Preliminary Design Evaluation of Sludge Dewatering, December 12, 1986
B-3
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1. EXISTING SLUDGE MANAGEMENT SYSTEMS
l.l JACKSON PIKE
Figure 1 presents Che sludge processing and disposal schematic currently
in operation at Jackson Pike. The sludge processing operations include:
• Primary sludge (PS) thickening in primary clarifiers
• Centrifuge thickening of waste activated sludge (WAS)
• Thickened sludge storage and blending (i.e. PS and WAS)
• Stabilization by anaerobic digestion or thermal conditioning
• Centrifuge dewatering
Dewatered sludge is disposed of in one of the following ways:
• Dewatered sludge is incinerated and the ash product is ultimately
landfilled.
• Dewatered sludge is land applied in an agricultural reuse program.
The Jackson Pike facility currently produces 230-250 wet tons per day of
dewatered sludge at a cake solids concentration of about 17 percent. On a dry
weight basis approximately 50 dry tons per day (dtpd) of dewatered solids are
produced for ultimate disposal. Based on recent operating records, approxi-
mately 50 percent of the dewatered sludge is incinerated and 50 percent is
land applied.
Table 1 identifies and describes the existing sludge management
facilities at Jackson Pike. The facility has provisions for short-term
storage of both PS and WAS outside of the main liquid processing stream. The
centrifuges for thickening of WAS were originally installed in 1975-76 and are
estimated to have a remaining useful life of approximately 10 years.
Thickened sludge storage and blending is accomplished using a secondary
digester. The anaerobic digestion facilities consist of eight primary
digesters constructed in 1937, and eight secondary digesters constructed in
B-4
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1950. Current practice utilizes two of the secondary digesters as short-term
sludge holding facilities. One digester is used as a mixing and blend tank as
identified previously, the second provides for storage of digested sludge
prior to dewatering. Based on information furnished by the city, the
structural integrity of the digesters is adequate; however, the mechanical
components have reached their useful life. The thermal conditioning units
have performed better than those at Southerly and have been maintained in good
operating condition, however, some process piping and mechanical
rehabilitation of the system is warranted. The centrifuge dewatering
equipment is less than 10 years old and has been rated as adequate for future
use. The multiple hearth incinerators were rebuilt in 1978-79. The units are
estimated to have 15-20 years of remaining useful service.
The existing land application program is accomplished through contract
operations. A local contractor is responsible for transport and spreading of
the sludge. The application program is operated approximately 260 days per
year, 5-6 days per week, applying 70 to 200 wet tons per day, 17 percent
solids, of dewatered cake depending on seasonal demand. In 1985, approxi-
mately 5800 dry tons of sludge were land applied, in 1986 approximately 6800
dry tons of sludge were applied. Dewatered sludge is normally removed from
the Jackson Pike site on a uniform basis to either land application under
favorable weather conditions or to storage sites located near the application
sites. The city also has utilized the Jackson Pike ash lagoons for temporary
short-term storage of dewatered cake. The city is pleased with the
performance of the application program. They believe land application has
been satisfactorily received by the community and tha't continuation of the
program should be included as part of any future planning. Adequate
application acreage appears available within a reasonable haul distance from
the treatment facility. Short-term storage of dewatered sludge has recently
been difficult and the city should address this problem if land application is
part of the future sludge management alternative.
Currently, incinerator ash is slurried and pumped to ash lagoons. The lagoons
are periodically dredged with the ash taken to a landfill. Plant staff have
B-7
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indicated that private landfill operators have declined to accept the ash.
Consequently, the only repository for the ash has been the city-owned
landfill.
1.2 SOUTHERLY
Figure 2 presents the sludge processing and disposal schematic currently
in operation at Southerly. The sludge processing operations include:
• Primary sludge (PS) thickening in primary clarifiers
• Centrifuge thickening of waste activated sludge
• Thickened sludge blending (i.e., PS and WAS)
• Centrifuge dewatering
Dewatered sludge is disposed of in one of the following ways:
• Dewatered sludge is incinerated and the ash product is ultimately
landfilled.
• Dewatered sludge is hauled to the composting facility and distributed
as a soil conditioner.
The Southerly facility currently produces 350-400 wet tons per day of
dewatered sludge at a cake solids concentration of about 17 percent. On a dry
weight basis, approximately 64 dry tons per day (dtpd) of dewatered solids are
produced for ultimate disposal. Based on recent operating records,
approximately 70 percent of the dewatered sludge is incinerated and the
remaining 30 percent is composted.
Table 2 identifies and describes the existing sludge management
facilities at Southerly. Primary sludge is thickened to approximately 4.5
percent in the primary clarifiers. The thickening of WAS by solid bowl
centrifuges was installed and operating in the latter part of 1986. The PS
and WAS is directed to separate tanks in a Sludge Control Building where it is
mixed prior to being pumped to the dewatering centrifuges.
B-8
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The anaerobic digestion facilties have not been operational since 1978,
but are currently undergoing rehabilitation. The anaerobic digestion system
at Southerly consists of four primary and two secondary digesters. The
thermal conditioning units have not operated at Southerly for almost 10 years.
Chloride stress corrosion which led to equipment deterioration and continuous
mechanical problems caused the abandonment of the thermal conditioning units.
The existing sludge dewatering facility at the Southerly plants consists
of six centrifuges which produce a final cake solids of 16-20 percent.
Dewatered sludge is disposed through incineration or composting. There are
two eight-hearth incinerators at Southerly which are each capable of burning
150 wet tons per day at 20-percent solids. Two new incinerators are in the
final stages of construction and start-up. The new incinerators will each
have a disposal capacity of 260 wet tons per day based on approximately 20
percent solids in the dewatered cake.
Dewatered sludge which is not incinerated is hauled by city-owned
vehicles to the composting facility where it is mixed, dried, screened, and
cured as a soil conditioner. The composting facility can normally accept 30
percent of the volume of solids produced by the Southerly plant with peak
capacity of 50 percent under ideal conditions. These ideal conditions relate
to dry weather and cake solids concentration.
Currently, the ash is placed in on-site ash lagoons. These ash lagoons are
periodically cleaned with the ash being removed to the city-owned landfill.
B-ll
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2. DEVELOPMENT OF SLUDGE MANAGEMENT ALTERNATIVES
Preliminary evaluations necessary to establish a foundation for the
preparation of the EIS required that alternative sludge management schemes be
identified and developed. The sludge management alternatives were formulated
in light of several goals and objectives. These goals and objectives included
the following:
• The sludge management alternatives must consist of processing and
disposal options that will provide for environmentally sound
processing and ultimate disposal of sludge.
• The alternative must provide a reliable means for future processing
and disposal.
• The alternatives should offer some flexibility allowing the city to
modify the processing and disposal methods to relieve pressures
created by equipment failures or temporary loss of the ultimate
disposal methods.
The alternatives developed should consider, to the extent possible,
optimizing the reuse of the existing facilities thus minimizing implementation
costs.
This preliminary evaluation identified alternatives for the two-plant
scenario, where Jackson Pike and Southerly would be operated independently,
and for the one-plant scenario, where Southerly is expanded to handle the
projected flows and loads and the Jackson Pike facility in abandoned. Under
the two-plant scenario, three alternative sludge management schemes were
identified for Jackson Pike, and six sludge management alternatives were
identified for Southerly. For the one-plant scenario (i.e., the consolidation
of wastewater treatment at Southerly) the sludge management alternatives which
were identified for the Southerly two-plant scenario were considered appropri-
ate to evaluate.
The alternatives which were identified were first subjectively screened
to eliminate those alternatives which did not adequately address future goals
B-12
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and objectives. Alternatives which advanced from the subjective evaluation
were then developed in greater detail through performance of a solids balance,
identification of required facilities and appropriate facilities sizes, and
development of a cost estimate for each alternative. Sizing criteria used
were consistent with current engineering practice. The cost estimates
prepared during the facilities planning process for required facilities were
reviewed in detail. For the most part, these estimates were considered
reasonable and reflective of facilities planning work. The cost estimates
developed in this briefing paper, revised and modified the facilities planning
estimates as appropriate to account for the difference between the
alternatives developed herein and the facilities plan alternatives. In areas
where the facilities planning estimate was not adequately supported, this
evaluation adjusted the estimates appropriately.
2.1 JACKSON PIKE SLUDGE MANAGEMENT ALTERNATIVES (TWO-PLANT SCENARIO)
Three potential sludge management alternatives were identified for the
Jackson Pike WWTP. Each alternative is discussed separately in the following
paragraphs.
2.1.1 Jackson Pike Sludge Management Alternative JP-A
Figure 3 presents the sludge managment schematic for alternative JP-A.
The alternative would involve the following sludge processes:
• Gravity thickening of PS
• Centrifuge thickening of WAS
• Thickened sludge storage and blending
• Stabilization by anaerobic digestion
• Centrifuge dewatering
Dewatered digested sludge would be land applied in an agricultural reuse
program.
B-13
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Based on the subjective review of this management alternative, it was
eliminated from further consideration. Relying strictly on land application,
for ultimate disposal of the projected sludge quantities, lacks the
flexibility critical to maintaining a successful disposal program. This lack
of flexibility would require an increased degree of conservatism in design and
implementation to ensure plant performance during an interruption of the
disposal process. Furthermore, the seasonal nature of the agricultural
application program would require substantial sludge storage facilities.
Normally, such storage facilities experience community relation difficulties
associated with aesthetics and odors.
2.1.2 Jackson Pike Sludge Management Alternative JP-B
Figure 4 presents the sludge management schematic for alternative JP-B.
This alternative would consist of the following sludge processes:
• Gravity thickening of PS
• Centrifuge thickening of WAS
• Thickened sludge storage and blending
• Stabilization by anaerobic digestion
• Centrifuge dewatering
• Incineration
Dewatered sludge would be disposed of as follows:
• 50 percent of the dewatered sludge would be incinerated and the ash
product landfilled.
• 50 percent of the dewatered sludge would be land applied.
The 50:50 ratio is approximately consistent with current Jackson Pike
disposal practices. In this brief analysis, a comprehensive review of alter-
nate ratios to determine an optimum was not performed. Since land application
is not a limiting factor and the incinerators at Jackson Pike require some
rehabilitation, a split equal to current practices appears appropriate.
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Subjective screening of JP-B indicated that the alternative adequately
addressed the goals and objectives. Therefore, it was developed for a more
detailed evaluation. Table 3 describes the facilities required and presents
the estimated costs to implement JP-B.
2.1.3 Jackson Pike Sludge Management Alternative JP-C
Figure 5 presents the sludge management schematic for alternative JP-C.
This alternative would consist of the following sludge processes.
• Gravity thickening of PS
• Centrifuge thickening of WAS
• Thickened sludge storage and blending
• Stabilization by anaerobic digestion
• Stabilization by thermal conditioning
• Centrifuge dewatering
• Incineration
Dewatered sludge would be disposed of as follows:
• 50 percent of the dewatered sludge would be incinerated and the ash
product landfilled.
• 50 percent of the dewatered sludge would be land applied.
As previously discussed, the 50:50 disposal ratio is consistent with
current practice. The stabilization processes would each handle 50 percent of
the thickened sludges produced under normal operating conditions. The
dewatered, thermally conditioned sludge would be incinerated while the
dewatered, digested sludge would be land applied.
Sludge management alternative JP-C was also determined by the subjective
screening to merit more detailed consideration. Table 4 describes the
facilities required and presents the estimated costs to implement JP-C.
B-17
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TABLE 3
JACKSON PIKE SLUDGE MANAGEMENT ALTERNATIVE
JP-B (Two-Plant Scenario)
Facilities and Estimated Costs
Gravity Thickening PS plus Dilution Water Pumping $1,967,000
Modify two (2)digesters; 85-foot dia. x 10-foot SWD
Centrifuge Thickening WAS $4,500,000
Two (2) existing; 500 gpm
One (1) new; 500 gpm
Thickened Sludge Storage/Blend
Existing Facilities Reused
Anaerobic Digestion $9,170,000
Six (6) existing; 85-foot dia. x 23.5-foot SWD
Centrifuge Dewatering $ 490,000
Six (6) existing; 1200 Ib/hr
Incineration
Two (2) existing, 7 hearth, 200 wet ton/day @ 20% solids $3,600,000
Landfill
Contract operations included with O&M
Land Application
Contract operations included with O&M —
Capital Cost $19,727,000
Annual Operation and $ 3,070,000
Maintenance Cost
Present Worth (JP-B Two-Plant) $41,827,000
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TABLE 4
JACKSON PIKE SLUDGE MANAGEMENT ALTERNATIVE
JP-C (Two-Plant Scenario)
Facilities and Estimated Costs
Gravity Thickening PS plus Dilution Water Pumping $1,967,000
Modify two (2) digesters; 65-foot dia. x 10-foot SWD
Centrifuge Thickening WAS $4,500,000
Two (2) existing; 500 gpm
One (1) new; 500 gpm
Thickened Sludge Storage/Blend
Existing Facilities Reused
Anaerobic Digestion $7,750,000
Six (6) existing; 85-foot dia. x 23.5-foot SWD
Thermal Conditioning
Two (2) existing; 200 gpm $3,000,000
Centrifuge Dewatering
Six (6) existing; 1200 Ib/hr $ 490,000
Incineration
Two (2) existing; 7 hearth, 200 wet ton/day @ 20% solids $3,600,000
Landfill
Contract operations included with O&M
Land Application
Contract operations included with O&M
Capital Cost $21,307,000
Annual Operations and $ 3,770,000
Maintenance Cost
Present Worth (JP-C Two-Plant) $48,597,000
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2.2 SOUTHERLY SLUDGE MANAGEMENT ALTERNATIVES (TWO-PLANT SCENARIO)
Six potential sludge management alternatives were identified for the
Southerly WWTP. Each alternative is discussed separately in the following
paragraphs.
2.2.1 Southerly Sludge Management Alternative SQ-A
Southerly sludge management alternative SO-A is graphically depicted by
the schematic presented in Figure 6. Alternative SO-A would utilize the
following sludge processes:
• Gravity thickening of PS
• Centrifuge thickening of WAS
• Thickened sludge storage and blending
• Stabilization by anaerobic digestion
• Centrifuge dewatering
• Incineration
Dewatered digested sludge would be incinerated and landfilled.
Alternative SO-A was eliminated from further consideration for two basic
reasons. First, the alternative proposes to abandon the existing compost
operations. Such a move would forfeit the substantial investment the city has
placed in the relatively new facilities and would substitute disposal of all
of the sludge product by landfilling in lieu of the current practice which
reuses a portion of the sludge as soil conditioner. Second, alternative SO-A
lacks the flexibility needed to allow the city to modify disposal operations
subject to equipment failures or external pressures such as public dissatis-
faction or regulatory requirements.
2.2.2 Southerly Sludge Management Alternative SO-B
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Figure 7 presents the sludge management schematic for alternative SO-B.
The alternative would feature the following sludge processes:
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• Gravity Chickening of PS
• Centrifuge thickening of WAS
• Thickened sludge storage and blending
• Centrifuge dewatering
• Composting
Ultimate sludge disposal would be accomplished through the marketing and
distribution of compost as a soil conditioner.
The subjective evaluation eliminated alternative SO-B from further
consideration. Flexibility to alter disposal operations was the critical
factor in the evaluation. Composting the entire volume of dewatered sludge
would mean a 2-3 fold increase in compost product over current conditions. If
Southerly were operated in a one-plant scenario, 5-6 times the current compost
product would be produced. An aggressive and successful marketing program
would be mandatory to locate and maintain sufficient receptors for the
compost. The long-term reliability of an alternative which relies solely on
distribution of compost was not considered adequate to merit more detailed
development and evaluation.
2.2.3 Southerly Sludge Management Alternative SO-C
The sludge management schematic for alternative SO-C is presented in
Figure 8. Southerly sludge management alternative SO-C would consist of the
following sludge processes:
• Gravity thickening of PS
• Centrifuge thickening of WAS
• Thickened sludge storage and blending
• Stabilization by anaerobic digestion
• Centrifuge dewatering
• Composting
• Incineration
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Dewatered sludge would be disposed of as follows:
• 75 percent of Che dewatered sludge would be incinerated, and the ash
product would be landfilled.
• 25 percent of the dewatered sludge would be composted and the compost
would be distributed as a soil conditioner.
The 75:25 ratio is approximately consistent with current Southerly
disposal practices. The digestion facilities would be sized to process that
portion of the sludge that would be incinerated. The portion of the sludge
that would be composted would not receive stabilization prior to dewatering.
Alternative SO-C represents current practice at Southerly when the
digestion facilities are operational. Therefore, subjective screening
concluded that the alternative merits more detailed development and
evaluation. Table 5 describes the facilities required and presents the
estimated costs to implement SO-C.
2.2.4 Southerly Sludge Management Alternative SO-D
Southerly sludge management alternative SO-D is graphically depicted by
the schematic presented in Figure 9. Alternative SO-D would utilize the
following sludge processes.
• Gravity thickening of PS
• Centrifuge thickening of WAS
• Thickened sludge storage and blending
• Stabilization by anaerobic digestion
• Centrifuge dewatering
• Composting
• Incineration
Ultimate disposal of the sludge would be accomplished through one of the
following disposal options.
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TABLE 5
SOUTHERLY SLUDGE MANAGEMENT ALTERNATIVE
SO-C (Two-Plant Scenario)
Facilities and Estimated Costs
Gravity Thickening PS plus Dilution Water Pumping $2,520,000
Four (4) existing; 45-foot dia. x 17-foot SWD
Centrifuge Thickening WAS $2,000,000
Four (4) existing; 250 gpm, 1250 Ib/hr
One (1) new; 250 gpm, 1250 Ib/hr
Thickened Sludge Storage/Blend
Existing Facilities Reused
Anaerobic Digestion $4,280,000
Six (6) existing; 85-foot dia. x 25.25-foot SWD
Centrifuge Dewatering $5,120,000
Six (6) existing; 1000 Ib/hr
Two (2) new; 1000 Ib/hr
Dewatered Sludge Storage $1,300,000
One (1) new; 400 cy plus material handling
Composting
Existing Facilities; 120 wet ton/day @ 20% solids
Incineration
Two (2) new; 8 hearth, 260 wet ton/day @ 20% solids
Landfill
Contract operations included with O&M
Capital Cost $15,220,000
Annual Operation and $ 3,260,000
Maintenance Cost
Present Worth (SO-C Two-Plant) $39,080,000
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• 25 percent of Che sludge would be dewatered, composted, and distri-
buted as a soil conditioner.
• 25 percent of the sludge would be digested, dewatered, and land
applied.
• 50 percent of the sludge would be digested, dewatered, incinerated,
and landfilled.
Alternative SO-D meets the goals and objectives of the subjective
screening. The alternative offers continuation of the existing incineration
and composting processes at Southerly and introduces land application as a
disposal process. The city has indicated there is adequate acreage suitable
for land application within an economically feasible distance of the plant.
Alternative SO-D was advanced for further development and evaluation. Table 6
describes the required facilities and presents the estimated costs to
implement SO-D.
2.2.5 Southerly Sludge Management Alternative SO-E
Figure 10 presents the sludge management schematic for Alternative SO-E.
Southerly sludge management alternative SO-E would consist of the following
sludge processes:
• Gravity thickening PS
• Centrifuge thickening of WAS
• Thickened sludge storage and blending
• Stabilization by anaerobic digestion
• Centrifuge dewatering
• Composting
Dewatered sludge would be disposed of as follows:
• 50 percent would be composted and distributed as a soil conditioner.
Sludge sent to compost would not go through the digestion process.
• 50 percent would be land applied as a fertilizer to agricultural
acreage within a reasonable distance from the plant.
B-29
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TABLE 6
SOUTHERLY SLUDGE MANAGEMENT ALTERNATIVE
SO-D (Two-Plant Scenario)
Facilities and Estimated Costs
Gravity Thickening PS plus Dilution Water Pumping $2,520,000
Four (4) existing; 45-foot dia. x 17-foot SWD
Centrifuge Thickening WAS $2,000,000
Four (4) existing; 250 gpm, 1250 Ib/hr
One (1) new; 250 gpm, 1250 Ib/hr
Thickened Sludge Storage/Blend
Existing Facilities Reused
Anaerobic Digestion $4,280,000
Six (6) existing; 85-foot dia. x 25.25-foot SWD
Centrifuge Dewatering $5,120,000
Six (6) existing; 1000 Ib/hr
Two (2) new; 1000 Ib/hr
Dewatered Sludge Storage $1,300,000
One (1) new; 400 cy plus material handling
Composting
Existing Facilities; 120 wet ton/day @ 20% solids
Incineration
Two (2) new; 8 hearth, 260 wet ton/day @ 20% solids
Landfill
Contract operations included with O&M —
Land Application
Contract operations included with O&M —
Capital Cost $15,220,000
Annual Operation and $ 3,340,000
Maintenance Cost
Present Worth (SO-D Two-Plant) $39,680,000
B-30
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Based on Che subjective evaluation alternative SO-E was eliminated from
further consideration. The reliability of utilizing only compost distribution
and land application as ultimate disposal options did not appear reasonable.
The plant currently practices incineration and relies heavily on incineration
and landfil-1 to dispose of sludge. Furthermore, it is critical that the plant
have a disposal method that is completely within their control, i.e., not
influenced by sludge quality, weather, market demand, public perception or
other external pressures.
2.2.6 Southerly Sludge Management Alternative SO-F
Figure 11 presents the sludge management schematic for Alternative SO-F.
Ths sludge management system would consist of the following processes:
• Gravity thickening PS
• Centrifuge thickening WAS
• Thickened sludge storage and blending
• Centrifuge dewatering
• Composting
• Incineration
Ultimate disposal of the sludge would be accomplished through one of the
following disposal options.
• 50 percent would be composted and distributed as a soil conditioner.
• 50 percent would be incinerated and landfilled.
Alternative SO-F is similar to alternative SO-C with the exception that
digestion is not provided. The evaluation of alternative SO-F was prompted
due to the fact that digestion prior to incineration has normally not proven
to be cost-effective. Although digestion diminishes the amount of solids to
be handled in subsequent processes, the heat content of digested sludge is
significantly reduced. Furthermore, digested sludge tends to be more
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difficult Co dewater than combined raw sludges. These factors cause digested
sludge to be more difficult, and consequently more expensive on a unit basis
(i.e. dollars per dry ton), than raw sludges to incinerate. Since the
Southerly plant has a portion of the required digestion facilities and
adequate incineration facilities in place, the cost effectiveness of digestion
prior to incineration is less dependent on capital cost than an evaluation
where these facilities are not in place.
Table 7 describes the required facilities and presents the estimated
costs to implement SO-F.
2.3 SOUTHERLY SLUDGE MANAGEMENT ALTERNATIVES (ONE-PLANT SCENARIO)
The three sludge management alternatives that were advanced from the
subjective screening phase for the Southerly two-plant scenario are considered
viable for Southerly one-plant scenario. These three alternatives were
previously identified as SO-C, SO-D, and SO-F. The remaining three
alternatives, which were identified for the two plant scenario, are not
considered viable for the one-plant scenario for the same reasons previously
discussed.
The sludge management schematics for alternatives SO-C, SO-D, and SO-F
have been presented in Figures 8, 9, and 11 respectively. Table 8 identifies
the required facilities and presents the estimated cost to implement sludge
management alternative SO-C under a one-plant scenario. Table 9 presents the
facilities and estimated costs to implement SO-D under a one-plant scenario.
Table 10 presents the facilities and estimated costs to implement SO-F under a
one-plant scenario.
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TABLE 7
SOUTHERLY SLUDGE MANAGEMENT ALTERNATIVE
SO-F (Two-Plant Scenario)
Facilities and Estimated Costs
•Gravity Thickening PS plus Dilution Water Pumping $2,520,000
Four (4) existing; 45-foot dia. x 17-foot SWD
_ Centrifuge Thickening WAS $2,000,000
• Four (4) existing; 250 gpm, 1250 Ib/hr
• One (1) new; 250 gpm, 1250 Ib/hr
• Thickened Sludge Storage/Blend
Existing Facilities Reused
Centrifuge Dewatering $8,750,000
Six (6) existing; 1000 Ib/hr
Four (4) new; 1000 Ib/hr
One (1) new; 400 cy plus material handling
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• Dewatered Sludge Storage $1,300,000
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Composting
Existing Facilities; 120 wet ton/day @ 20% solids
Incineration
Two (2) new; 8 hearth, 260 wet ton/day @ 20% solids
Landfill
Contract operations included with O&M
Capital Cost $14,570,000
Maintenance Cost
Present Worth (SO-C Two-Plant) $42,770,000
•Annual Operation and $ 3,940,000
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TABLE 8
SOUTHERLY SLUDGE MANAGEMENT ALTERNATIVE
SO-C (One-Plant Scenario)
Facilities and Estimated Costs
Gravity Thickening PS plus Dilution Water Pumping $5,070,000
Four (4) existing; 45-foot dia. x 17-foot SWD
Two (2) new; 85-foot dia. x 10-foot SWD
Centrifuge Thickening WAS $5,600,000
Four (4) existing; 250 gpm, 1250 Ib/hr
Four (4) new; 250 gpm, 1250 Ib/hr
Thickened Sludge Storage/Blend
Existing Facilities Reused
Anaerobic Digestion $11,460,000
Six (6) existing; 85-foot dia. x 25.25-foot SWD
Four (4) new; 85-foot dia. x 25.25-foot SWD
Centrifuge Dewatering $21,040,000
Six (6) existing; 1000 Ib/hr
Nine (9) new; 1000 Ib/hr
Dewatered Sludge Storage
One (1) new; 400 cy plus material handling $1,300,000
Composting
Existing Facilities; 120 wet ton/day @ 20% solids
Incineration
Two (2) new; 8 hearth, 260 wet ton/day @ 20% solids
Rehabilitate existing $1,300,000
Landfill
Contract operations included with O&M —
Capital Cost $45,770,000
Annual Operation and $ 6,080,000
Maintenance Cost
Present Worth (SO-C One-Plant) $89,590,000
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TABLE 9
SOUTHERLY SLUDGE MANAGEMENT ALTERNATIVE
SO-D (One-Plant Scenario)
Facilities and Estimated Costs
Gravity Thickening PS plus Dilution Water Pumping $5,070,000
Four (4) existing; 45-foot dia. x 17-foot SWD
Two (2) new; 85-foot dia. x 10-foot SWD
Centrifuge Thickening WAS $5,600,000
Four (4) existing; 250 gpra, 1250 Ib/hr
Four (4) new; 250 gpm, 1250 Ib/hr
Thickened Sludge Storage/Blend
Existing Facilities Reused
Anaerobic Digestion $11,460,000
Six (6) existing; 85-foot dia. x 25.25 foot SWD
Four (4) new; 85-foot dia. x 25.25 foot SWD
Centrifuge Dewatering $21,040,000
Six (6) existing; 1000 Ib/hr
Nine (9) new; 1000 Ib/hr
Dewatered Sludge Storage
One (1) new, 400 cy plus material handling $1,300,000
Composting
Existing Facilities; 120 wet ton/day @ 20% solids
Incineration
Two (2) new; 8 hearth, 260 wet ton/day @ 20% solids
Rehabilitate existing $1,300,000
Landfill
Contract operations included with O&M —
Land Application
Contract operations included with O&M —
Capital Cost $45,770,000
Annual Operation and $ 6,230,000
Maintenance Cost
Present Worth (SO-D One-Plant) $90,710,000
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TABLE 10
SOUTHERLY SLUDGE MANAGEMENT ALTERNATIVE
SO-F (One-Plant Scenario)
Facilities and Estimated Costs
Gravity Thickening PS plus Dilution Water Pumping $5,070,000
Four (4) existing; 45-foot dia. x 17-foot SWD
Two (2) new; 85-foot dia. x 10-foot SWD
Centrifuge Thickening WAS $5,600,000
Four (4) existing; 250 gpm, 1250 Ib/hr
Four (4) new; 250 gpm, 1250 Ib/hr
Thickened Sludge Storage/Blend
Existing Facilities Reused
Centrifuge Dewatering $27,430,000
Six (6) existing; 1000 Ib/hr
Fourteen (14) new; 1000 Ib/hr
Dewatered Sludge Storage
One (1) new; 400 cy plus material handling $1,300,000
Composting
Existing Facilities; 120 wet ton/day @ 20% solids
Incineration
Two (2) new; 8 hearth, 260 wet ton/day @ 20% solids
Rehabilitate existing $1,300,000
Landfill
Contract operations included with O&M —
Capital Cost $40,700,000
Annual Operation and $ 7,110,000
Maintenance Cost
Present Worth (SO-F One-Plant) $92,440,000
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3. EVALUATION OF SLUDGE MANAGEMENT ALTERNATIVES
Sludge management alternatives were evaluated based on cost-
effectiveness, dewatering, system redundancy, and ultimate disposal. Facility
planning information is included for each of the criteria. The results of the
evaluation are discussed in the following sections.
3.1 COST EFFECTIVENESS OF SLUDGE MANAGEMENT ALTERNATIVES
Table 11 presents the potential sludge management alternatives and the
associated present worth of each. These alternatives and the present worth
costs will be utilized in a subsequent briefing paper to assess the cost
effectiveness of the one-plant and two-plant scenarios.
Alternative JP-B, which provides for digestion, dewatering, and a 50:50
split of the sludge to land application and incineration and landfill, is the
cost-effective sludge management scheme at Jackson Pike. This alternative is
approximately 16 percent less costly than JP-C which proposes to retain the
thermal conditioning units for processing a portion of the sludge.
The lowest present worth of the Southerly two-plant alternatives is
exhibited by SO-C. Practically speaking, however, present worth of SO-D is
considered equal to that of SO-C. At this level of planning analysis the 1.5
percent present worth difference is not a significant factor in selection of
an alternative. In light of this fact, SO-D is the recommended sludge
management alternative for the Southerly two-plant scenario. Alternative SO-D
offers more flexibility in that three disposal methods are utilized (i.e.,
marketing of a compost product, land application of dewatered, digested
sludge, and landfilling of incinerator ash.) SO-C on the other hand utilizes
only two of the disposal options, not providing for land application.
Alternative SO-F was developed to evaluate the cost effectiveness of
digestion prior to incineration. SO-F proposes dewatering of raw sludge with
approximately 50 percent of the dewatered cake incinerated. Alternative SO-F
B-39
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TABLE 11
PRESENT WORTH COMPARISON
OF SLUDGE MANAGEMENT ALTERNATIVES
SCENARIO
TWO-PLANT
ONE-PLANT
ALTERNATIVE
JP-B
JP-C
SO-C
SO-D
SO-F
so-c
SO-D
SO-F
PRESENT WORTH
$ 41,827,000
$ 48,597,000
$ 39,080,000
$ 39,680,000
$ 42,777,000
$ 89,590,000
$ 90,710,000
$ 92,440,000
RECOMMENDED
ALTERNATIVES
JP-B + SD-D
$ 81,507,000
SO-D
$ 90,710,000
ALTERNATIVE PROCESS / DISPOSAL INDEX
DIGESTION
THERMAL CONDITIONING
DEWATERING
INCINERATION
COMPOST
LAND APPLICATION
LANDFILL
REFERENCE
JP-B
•
•
•
•
•
FIG, 4
JP-C
•
•
•
•
•
•
FIG. 5
so-c
•
•
•
•
•
FIG. 8
SO-D
•
•
•
•
•
•
FIG. 9
SO-F
•
•
•
•
FIG. 11
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differs from SO-C only in Chat the digestion provided in SO-C is not included
in SO-F. From Table 11 it can be seen that alternative SO-F (i.e., incinera-
tion without digestion) exhibits a present worth approximately 9 percent
higher than alternative SO-C.
Digestion prior to incineration has proven to be cost effective in this
case primarily due to the sunken capital invested in the Southerly facilities.
Southerly has six existing anaerobic digesters and four multiple hearth
incinerators in place (i.e., two existing and two in startup). The new
incinerators are equipped with a waste heat recovery system which reclaims
waste heat from the incinerators to meet digestion and building heat require-
ments. The waste heat recovery system allows for the digester gas produced to
be used as a fuel for the incinerators, thus substantially reducing the
supplemental fuel requirements of the incinerators.
The existing digestion, incineration, and waste heat recovery facilities
conservatively represent 20-25 million dollars of sunken capital. If these
facilities were not in place, the required additional capital costs would be
sufficient to show incineration of raw sludge to be more cost effective than
digestion prior to incineration.
Under the one-plant scenario, sludge management alternatives SO-C and
SO-D represent the lowest present worth options. Again digestion prior to
incineration (SO-C) is a lower cost alternative than digestion of raw sludge
(SO-F). However, the difference between SO-C and SO-F has been diminished to
approximately 3 percent. This smaller difference is due to the fact that four
new digesters are required in the one-plant scenario. The cost of the four
new digesters weakens the impact of the sunken capital in the cost effective-
ness analysis and thus lowers the present worth difference.
As with the Southerly two-plant scenario, alternative SO-D is recommended
as the preferrable Southerly one-plant sludge management scheme. For the
reasons previously discussed, SO—D provides the city with three reliable
disposal paths and adequate flexibility.
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3.2 SLUDGE DEWATERING
The RFPU evaluated the sludge dewatering component of the various
alternatives in light of the existing centrifuge equipment currently in
service at Southerly. The design criteria for the dewatering centrifuges was
revised a number of times over the course of the planning and design.
Facilities planning documents indicate the centrifuges will be rated at
120 gpm with a feed solids of 5 percent, or approximately 3000 Ibs/hr.
Subsequently, the GERBOD revised the design criteria for the centrifuges to
1000 Ibs/hr. Based on a feed solids of 4 percent, the GERBOD assumed a
dewatered cake of 20-21 percent could be produced. The GERBOD further
indicated that the successful, efficient operation of the dewatering process
is critical to the overall cost of sludge processing and disposal. The GERBOD
noted that increasing the solids content of the dewatered cake reduces
incinerator fuel consumption and subsequent handling costs, and increases the
efficiency of downstream processes. The GERBOD concluded recommending that
alternative dewatering equipment (specifically belt presses and diaphragm
plate and frame (DPF) presses) be fully evaluated to optimize the sludge
processing scheme.
As a result of the GERBOD's recommendations, pilot scale testing of
dewatering equipment was conducted. The pilot testing and subsequent
dewatering evaluations were documented in the Preliminary Design Evaluation of
Sludge Dewatering, December 12, 1986. The evaluation acknowledges that the
tests were carried out under less than optimum conditions. Tests were
performed on unthickened, undigested sludge of indeterminate composition. The
proportions of primary and waste activated sludge fed to the dewatering
devices could only be approximated.
The dewatering evaluation selected the diaphragm plate and frame press as
the optimum dewatering alternative. The evaluation recommended installation
of four DPF presses in Project 88 and the future installation of an additional
five DPF presses—to provide a total of nine presses. The six (6) existing
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dewatering centrifuges will become standby units after the Project 88 improve-
ments and will eventually be abandoned as the treatment plant project proceeds
and the remaining DPF presses are installed.
The dewatering evaluation also recommended that the diaphragm plate and
frame presses be located in the existing thermal conditioning building with
appropriate modifications to that structure. The estimated cost for implemen-
ting the DPF recommendation, presented in the dewatering evaluation, was
approximately $22,000,000 The cost estimate previously presented in the
facilities plan and utilized in the cost-effective evaluation for implementing
the centrifuge dewatering alternative was approximately $12,000,000. Both of
these estimates are based on the one-plant scenario.
In the evaluation of dewatering alternatives the capacity of the
centrifuges was again revised. Based on the interpretation of pilot test
results, the capacity of the centrifuges was established at 700-750 Ib/hr. As
a result, 17 centrifuges (i.e., 14 operating, 3 standby) were needed to
dewater approximately 240,000 Ibs/day of sludge.
Following the pilot testing, one of the existing centrifuges was modified
and upgraded to allow a full-scale test. The feed sludges used were still not
representative of the future anaerobically digested sludge. Review of the
data from this full-scale demonstration indicates that the modified centrifuge
could process in excess of 1000 Ibs/hr (i.e., 1300-1700 Ibs/hr) on various
blend ratios of the existing sludge.
Due to the sunken investment in the six existing centrifuges, the
established design capacity of modified units is important to the selection of
the optimum dewatering alternative.
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Based on the data contained in the Preliminary Design Evaluation of
Sludge Dewatering, use of less than 1000 Ibs/hr as the rated capacity of the
modified centrifuge seemed unusually conservative. Consequently, an
independent cost-effective evaluation of dewatering was performed using
1000 Ibs/hr as the design capacity. This independent analysis was performed
based on the Southerly one-plant scenario. The results of this analysis are
summarized in Table 12. Since the effectiveness of the dewatering devices
impact downstream processing units, the operational costs of incineration and
ash disposal have been included in the cost-effective analysis. The
centrifuge dewatering option at $40,800,000 exhibits a 7 percent lower present
worth than the DPF option at a present worth of $43,600,000.
As a result of the higher rated capacity of the centrifuges, fewer units
would be required. Fifteen units, 12 operating and 3 standby would be
adequate. Assuming the thermal conditioning building was the logical location
for the dewatering facility, a smaller expansion of that structure would be
necessary. Fewer centrifuges and associated equipment and less building
expansion result in Che estimated cost of centrifuge dewatering approximately
equal to that of the DPF press option (i.e., $22,000,000).
The operation and maintenance costs associated with the two dewatering
alternatives are reasonably consistent with those developed in the Preliminary
Design Evaluation of Sludge Dewatering. The DPF presses are approximately
45 percent more expensive to operate and maintain primarily due to higher
labor costs and higher chemical costs.
The centrifuges will provide a 20 percent cake solids concentration,
whereas the DPF presses will provide a 25 percent cake solids concentration.
Consequently, the operating cost of incineration is approximately 80 percent
higher for the centrifuge dewatered sludge. The supplemental fuel required to
burn off the additional water is the major reason for this difference. From
Table 12, it can be seen that operational costs for the incineration process
are $500,000 higher under the centrifuge dewatering alternative. The
Preliminary Design Evalution of Sludge Dewatering identified a $750,000
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TABLE 12
PRESENT WORTH COMPARISON
OF DEWATERING ALTERNATIVES
PROCESS
DEWATERING
INCINERATION
ASH DISPOSAL
TOTAL
PRESENT
WORTH
CENTRIFUGE _
ALTERNATIVE
CAPITAL
$ 21,040,000
$ 0
$ 0
$ 21,040,000
0 & M
$ 1,300,000
$ 1,100,000
$ 330,000
$ 2,730,000
$ 40,800,000
DPF PRESS ,
ALTERNATIVE
CAPITAL
$ 21,920,000
$ 0
$ 0
$ 21,920,000
0 & M
$ 1,910,000
$ 600,000
$ 490,000
$ 3,000,000
$ 43,600,000
BASED DN 15 CENTRIFUGES <12 OPERATING AND 3 STANDBY), RATED
CAPACITY DF 1,000 LBS / HR / UNIT, PRODUCING CAKE SOLIDS
CONCENTRATION OF 20-PERCENT.
BASED DN 9 DPF PRESSES <7 OPERATING AND 2 STANDBY), RATED
CAPACITY OF 35,000 LBS / DAY / UNIT EXCLUDING PRECOAT SOLIDS,
PRODUCING CAKE SOLIDS CONCENTRATION OF 25-PERCENT.
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difference in incinerator operating costs, also with the centrifuge dewatering
alternative being higher.
The facilities planning documents and the Preliminary Design Evaluation
of Sludge Dewatering do not address the ultimate disposal of incinerator ash.
As described in Section 1 of this briefing paper, currently ash is stored in
on-site ash lagoons and periodically removed to a landfill site. Due to the
fact that a substantial quantity of inert solids are added to the sludge under
the DPF press alternative, a larger quantity of ash is produced. Consequently,
the costs associated with ash disposal will be higher for the DPF press
alternative. For purposes of this analysis, an ash disposal cost of $15 per
cubic yard was utilized. Based on this unit cost and the projected ash
quantities, ash disposal under the DPF press alternative will be $160,000
(i.e., approximately 50 percent) more costly than ash disposal for the
centrifuge dewatering alternative.
The briefing paper analysis of dewatering alternatives reached a
different conclusion than the Preliminary Design Evaluation of Sludge
Dewatering for several reasons. These reasons are briefly discussed below.
• Use of the higher capacity rating for the centrifuges in the briefing
paper analysis, resulted in lower capital costs for the centrifuge
alternative.
• Although the Preliminary Design Evaluation of Sludge Dewtering
projected higher operating costs for the DPF presses than the
centrifuges (i.e., approximately 15 percent higher), this difference
was increased to 45 percent in the briefing paper analysis.
• The supplemental fuel required by the incineration process was higher
for both alternatives in the briefing paper analysis. This is due to
the fact that heat value of digested sludge was taken as 8000 BTU/lb
of volatile solids. In the Preliminary Design Evaluation the heat
value of digested sludge was taken as 10,000 BTU/lb of volatile
solids. This difference in sludge heat value necessitated that
supplemental fuel be added to the DPF press alternative in the
briefing paper analysis, whereas in the Preliminary Design Evaluation
the DPF press dewatered solids required no supplemental fuel.
The two analyses also utilized different unit costs for supplemental
fuel (No. 2 fuel oil). The Preliminary Design Evaluation used $1.05
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per gallon. The briefing paper analysis used $0.85 per gallon based
on telephone conversations with fuel suppliers. Reviewing the 1985
Operating Report for the Division of Sewerage and Drainage indicated
that Southerly was purchasing fuel oil at a cost of $0.66 per gallon.
The net impact of both of these differences (i.e., heat value of
digested sludge and cost of fuel oil) was that the briefing paper
analysis estimated less of an economic advantage for the DPF press
alternative in the incineration process.
• Lastly, the briefing paper analysis included a cost for ash disposal,
whereas the preliminary design evaluation did not. Since more ash is
produced with the DPF presses, this slightly favored the centrifuge
alternative in this cost-effective analysis.
From the above analyses it is evident that the selection of a dewatering
alternative is sensitive to the capacity criteria established for the devices
being evaluated and the final sludge cake solids concentrations these units
can produce. In light of this sensitivity, it appears reasonable to conduct
testing programs on sludges similar to that which will be processed in the
future (i.e., in this case anaerobically digested) to provide a representative
picture of probable equipment performance. If such testing is not possible
for whatever reason, selection of conservative design criteria appears
justified for the initial project phase. However, the six existing modified
centrifuges should be evaluated with anaerobically digested sludge prior to
abandoning these units and implementing the final project phases.
3.3 PLANNED SYSTEM REDUNDANCY
The facilities planning documents recommended a sludge management
alternative which provided redundancy in accordance with Table 13. The table
is based on a Southerly one-plant scenario.
The recommended alternative calls for 22 percent of the dewatered sludge
to be composted under normal conditions. The compost facility has a capacity
to handle as much as 55 percent of the sludge under ideal conditions. Ideal
conditions relate to total solids content of dewatered sludge, favorable
weather conditions for composting, and adequate demand for the compost
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TABLE 13. SLUDGE MANAGEMENT SYSTEM REDUNDANCY
FOR FACILITIES PLAN RECOMMENDATION
Process/Disposal
Average
Annual
Maximum
Capacity
Values as a percentage of
annual sludge production
Compost/Sales & Distribution
Digest/Land Apply
Digest/Incinerate/Landfill
Lime Stabilization/Land Apply
22
19a
59a
c
55
67
80b
c
a Digestion to handle total of sludge incinerated and land applied, i.e.,
approximately 80 percent of average annual sludge production.
Incineration to provide complete redundancy for either composting or land
application processes.
c Lime stabilization is proposed by the facilities plan as a backup process,
however, the sizing criteria and the need for these facilities are not
clear.
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product. The compost facility is planned to operate in a range of 120 wet ton
per day on the low side, up to more than 240 wet ton per day at maximum.
Approximately 20 percent of the average annual sludge production would be
digested, dewatered, and land applied. The current appplication program has
been successful, and the city anticipates that the demand for the dewatered
sludge product will remain. The extent to which land application can
function as a disposal option is subject to several factors including weather
conditions and cropping patterns. Consequently, the amount of sludge which
will be land applied is expected to vary substantially throughout the year.
The program will operate from virtually no land application when factors
preclude application to a maximum of 60-70 percent of the average annual
sludge production (on a daily basis) being land applied during favorable
application circumstances.
Approximately 60 percent of the annual sludge production would be
incinerated. The planning documents indicate the incineration facility,
however, would be sized to handle a maximum of as much as 80 percent of the
sludge production. This additional 20-percent would function as a valuable
backup for either the composting or the land application disposal option. In
the event either of these options are unable to process and dispose of their
planned portion of the average annual sludge production, incineration and
landfilling would be available to alleviate the problem. The incineration/
landfill option would be expected to routinely backup the land appplication
option for reasons previously discussed. The composting option would be
expected to perform more consistently than land application. If incineration
were needed as a backup to composting, it should be on a scheduled basis at a
time when land application could reasonably be expected to provide disposal
for a minimum of 20 percent of the sludge production.
In addition to the three processing and disposal options discussed above,
the facilities plan recommends that lime stabilization and land application be
provided as a backup to other ultimate disposal options. Figure 5.3 of the
RFPU indicates that the lime facilities would be sized only to backup the
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compose process, however, the details are not adequate to determine what is
proposed. Furthermore, the need for this additional redundancy has not been
justified. Recent correspondence with the city (i.e., May 29, 1987, URS
Dalton Responses to May 12, 1987 Comments) indicates the recommendation of
lime facilities has not been finalized completely and is being reevaluated due
to the cost of these facilities.
In this briefing paper analysis the redundancy issue was considered
relative to the existing and new incineration facilities at Southerly. The
two new incinerators at Southerly will be capable of incinerating approximate-
ly 525 wet tons per day of dewatered cake at 20 percent solids. If a
dewatered cake solids of 25 percent can be realized, these two units would be
capable of incinerating approximately 560 wet tons per day. The two existing
incinerators, which according to the planning documents will be rehabilitated
under a one-plant option, are capable of incinerating 320 wet tons per day at
20 percent solids. Again, if a 25 percent cake solids concentration can be
obtained, these units would be capable of 350 wet ton per day. For purposes
of comparison, the total dewatered sludge cake production of Southerly under a
one-plant scenario assuming all sludge was directed to incineration would be
approximately 510 wet tons per day at 20 percent solids and 410 wet tons per
day at 25 percent solids. With one new (larger) incinerator out of service,
the remaining three incinerators can handle 15 percent more sludge at 20
percent solids than the one-plant option can produce. With a dewatered cake
concentration of 25 percent solids, these three incinerators could process
more than 50 percent more sludge than the one-plant option can generate.
Based on the above analysis, the incineration process offers sufficient
redundancy to allow processing and disposal of all sludge produced even when
the composting and land application options are inoperative and one of the
larger incinerators is out of service. In light of the redundancy inherent in
the incineration process, the need for greater redundancy does not appear
justified.
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3.4 ULTIMATE DISPOSAL PLAN
The facilities plan proposes three basic methods for ultimate
use/disposal of the wastewater sludges. They are:
• Distribution and Marketing of Composted Sludge
• Land Application of Digested, Dewatered Sludge
• Landfilling of Incinerated, Dewatered Sludge
The plan, however, does not offer many details relating to the operation,
costs, and planned reliability associated with these options. The following
paragraphs briefly present the current understanding of the use/disposal
options.
3.4.1 Distribution and Marketing of Composted Sludge
Dewatered, undigested sludge is transported by the city in trucks to the
composting facility. The city operates and maintains the compost facility
which most recently has been processing approximately 120 wet tons/day of
dewatered sludge from Southerly. Conversations with city personnel have
indicated that the composting facility costs approximately $1,200,000 per year
to operate. The 1985 Operating Report published by the Division of Sewerage
and Drainage shows the 1985 operating budget for the compost facility to be
$2,000,000. Based on these costs and the total production of the composting
facility, a unit cost of $26-40 per wet ton of sludge composted is estimated.
Currently compost is disposed of through mine reclamation projects, bulk and
residential package sales, and nursery and institution use. The city has an
active marketing program and anticipates that future demand will be adequate
to dispose of the compost produced.
The composting facility has been cited as a source of odors by the
community. The city believes that most of the odor problems can be attributed
to the moisture content in the raw sludge and problems with the composting
equipment. The city anticipates that future operations will increase
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dewatered solids concentration and reduce the potential for odors from the
facility.
3.4.2 Land Application of Digested, Dewatered Sludge
The current land application program originates from the Jackson Pike
plant. Currently land application is conducted on a contract basis and it is
expected that this practice will continue in the future. Based on
conversations with city personnel, the current cost of land appplication is
approximately $12 per wet ton of sludge applied. The contractor is
responsible for transport and spreading the sludge and for remote sludge
storage if necessary.
Based on the earlier EIS (1979), adequate suitable acreage for sludge
application is available within a reasonable distance of the plant site. The
current program is subject to substantial variation in peak and off peak
application rates due to weather and crop constraints. Recent discussions
have indicated that remote sludge storage has become limited as farmers have
decided to accept the sludge only if it is spread immediately. The ash
lagoons at Jackson Pike have been utilized to provide temporary storage and
relieve the pressure this situation has created.
The future land application program should be planned and administered by
the city in such a way as to ensure the reliability of the agricultural use of
sludge.
3.4.3 Landfilling of Incinerated Dewatered Sludge
At both Jackson Pike and Southerly, incinerator ash is temporarily stored
in on-site ash lagoons. The lagoons are cleaned on an as-needed basis with
the ash being transported and deposited in a landfill by a contractor. The
cost of ultimate disposal of ash has not been identified. These costs vary
significantly depending on local availability of landfills, transport
distances, and composition of the ash. Deposit charges alone can range
between $5-20 per cubic yard and may be substantially higher depending on
local conditions and ash quality.
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Conversations with the city have indicated that only the city-owned
landfill is accepting the incinerator ash. Details relating to the projected
useful life of this landfill are not contained in the facilities plan. For
the EIS to review the reliability of the landfill disposal option, the city
must furnish planning information documenting the steps being taken to ensure
a suitable disposal site will be available.
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APPENDIX C
BRIEFING PAPER NO. 3
BIOLOGICAL PROCESS SELECTION
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BRIEFING PAPER NO. 3
I
BIOLOGICAL PROCESS SELECTION
I
I Supplemental Environmental Impact Statement
USEPA Contract No. 68-04-5035, D.O. No. 40
| Columbus Ohio Waste-water Treatment Facilities
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• Prepared By:
| SCIENCE APPLICATIONS INTERNATIONAL CORPORATION
• TRIAD ENGINEERING INCORPORATED
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BIOLOGICAL PROCESS SELECTION
1. TERMS AND DEFINITIONS
2. BRIEFING PAPER ASSUMPTIONS
3. PROCESS EVALUATION
3.L Process Description
3.1.1 Design Criteria
3.1.1.1 Aeration Basins
3.1.1.2 Trickling Filters
3.1.1.3 Clarifiers
3.1.2 Recommended Sizing
3.1.2.1 Southerly Two-Plant Semi-Aerobic
3.1.2.2 Southerly Two-Plant Trickling Filter/Activated Sludge
3.1.2.3 Jackson Pike Two-Plant Semi-Aerobic
3.1.2.4 Jackson Pike Two-Plant Trickling Filter/Activated Sludge
3.1.2.5 Southerly One-Plant Semi-Aerobic
3.1.2.6 Southerly One-Plant Trickling Filter/Activated Sludge
3.2 Technical Evaluation
3.2.1 Reliability
3.2.2 Flexibility
3.3 Environmental Evaluation
3.4 Cost Evaluation
4. COMPARISON OF BRIEFING PAPER AND FACILITY PLAN CONCLUSIONS
4.1 Process Selection
4.2 Clarifier Utilization
4.3 One-Plant versus Two-Plants
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INTRODUCTION
Under the direction of USEPA, a series of briefing papers are being
prepared addressing key issues in the development of the Supplemental
Environmental Impact Statement for the Columbus, Ohio, Wastewater Treatment
Facilities. The briefing papers form the basis of discussions between USEPA
and their consultants to resolve these key issues. The following paragraphs
present the background of the facility planning process, a description of the
briefing papers, and the purpose of this paper on biological process
selection.
FACILITY PLANNING PROCESS
At the time this paper was prepared (March-July 1987) the city of
Columbus was proceeding to implement improvements at the Jackson Pike and
Southerly Wastewater Treatment Plants to comply with more stringent effluent
standards which must be met by July 1, 1988. These improvements were based
on the consolidation of wastewater treatment operations at the Southerly
plant. This one-plant alternative is a change from the two-plant operation
proposed by the city in the 1970's and evaluated in the 1979 EIS.
The development and documentation of wastewater treatment process and
sludge management alternatives for the Columbus metropolitan area has been an
extended and iterative process. The design and construction of various
system components have progressed, because of the 1988 deadline, while
planning issues continue to be resolved. As a result, numerous documents have
been prepared which occasionally revise a previously established course of
direction.
The concurrent resolution of planning issues and implementation of
various project components has made preparation of the EIS more difficult
because final facility plan recommendations are not available in a single
document.
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BRIEF-ING PAPERS
To facilitate preparation of the EIS, a series of briefing papers are
being developed. The purpose of the briefing papers is to allow USEPA to
review the work of the EIS consultant and to identify supplemental information
necessary for the preparation of the EIS. Six briefing papers are being
prepared as follows:
• Flows and Loads
• Sludge Management
• Process Selection
• CSO
• One Plant vs. Two Plant (Alternative Analysis)
• O&M and Capital Costs
The specific focus of each briefing paper will be different. However,
the general scope of the papers will adhere to the following format:
• Existing conditions will be documented.
• Evaluations, conclusions, and recommendations of the facilities
planning process will be reviewed using available documentation.
• Where appropriate, an independent evaluation of the future situation
and viable alternatives will be prepared.
• The facility plan and EIS briefing paper conclusions will be compared.
The briefing paper process is intended to:
• Prompt the resolution of any data deficiencies.
• Clearly establish and define existing and future conditions.
« Identify the final recommended plan which the city desires to implement.
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• Provide a data base of sufficient detail to allow preparation of the
draft EIS.
BIOLOGICAL PROCESS SELECTION
This Briefing Paper presents an evaluation of three different biological
processes selected by the city of Columbus, for use at the Jackson Pike and
Southerly Wastewater Treatment Plants (WWTP). The scope of this report is to
review data made available by the city's consultant, identify issues and data
gaps, aid USEPA in the decision making process, and focus on future data needs
so that a complete and thorough Environmental Impact Statement may be
prepared.
The biological processes to be evaluated include the semi-aerobic process
(SA), conventional activated sludge process (AS), and trickling filters
followed by activated sludge (TF/AS). Data provided by the city's consultant
was evaluated against Ten State Standards, USEPA Design Criteria Documents,
and established literature values for critical design conditions for each of
the selected processes. The process evaluation includes a process descrip-
tion, a review of the technical criteria from each of the process trains
including reliability, flexibility, performance, expandability and turndown,
and environmental impacts. Capital costs are also evaluated based on the
selection of system sizing and components necessary to meet Ohio EPA effluent
discharge standards. The final section of the report deals with conclusions
and recommendations based on data available to date.
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1. TERMS AND DEFINITIONS
An evaluation of municipal biological treatment processes requires a
fundamental knowledge of terminology used by design engineers. The following
key words used in this briefing paper are defined to assist the reader in
understanding the key issues raised during process evaluation.
Semi-Aerobic The semi-aerobic process is a modified activated sludge system
which contains an initial anaerobic/anoxic conditioning stage consisting of a
mixture of aerobic return activated sludge and raw primary effluent followed
by aerobic treatment. This process uses an anaerobic selector zone to control
bulking sludge.
Anaerobic - A biological treatment process that occurs in the absence of
oxygen. This process contains bacteria that can survive only in the absence
of any dissolved oxygen. These bacteria are known as obligate anaerobes. The
anaerobic section of the semi-aerobic process is critical in providing a
selector mechanism against those bacteria which cause bulking in a municipal
waste treatment plant.
Anoxic - A condition of low dissolved oxygen (less than 0.3 mg/1) or a
condition in which the only source of oxygen is mineral bound oxygen such as
nitrates. Anoxic denitrification is a process by which nitric oxygen is
converted biologically into nitrogen gas in the absence of dissolved oxygen.
In the semi-aerobic process, the anoxic zone may change from anaerobic to
anoxic depending on the level and concentration of nitrates in the wastewater.
Biological Phosphorus Removal - (Also called Bio-P Removal) A process by which
phosphorus associated with biological cells, is precipitated from the
wastewater and contributes to the sludge of a biological treatment system.
The semi-aerobic process results in biological phosphorus removal. The city's
consultant estimates that excess phosphorus removal results in approximately
4.5 milligrams additional sludge per milligram of phosphorus removed from the
mixed liquor suspended solids. The mechanism which triggers removal is not
well understood; however, in plants where a phosphorus effluent limitation is
in effect, biological phosphorus removal is an additional benefit. Where
biological phosphorus removal cannot be triggered, physical-chemical
phosphorus removal must be employed. In all cases, the removal of phosphorus
from the wastewater increases the sludge yield from the biological treatment
train.
Bulking Sludge/Rising Sludge - A bulking sludge is one which shows poor
settleability as measured by the sludge volume index (SVI Test). The cause of
a bulking sludge is generally filamentous algae or bacteria. The microbe
responsible for bulking at the Southerly wastewater treatment plant has been
identified as the cyanobacterium Schizothrax calcicola (Phorraidium). Because
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of its poor settling characteristics a bulking sludge will cause BOD and total
suspended solids violations due to the loss of particulates over the weirs of
the secondary clarifier. High SVI numbers are indicative of a bulking sludge.
A rising sludge is one in which the sludge blanket of the secondary clarifiers
floats to the surface, once again causing TSS and BOD violations. Rising
sludges are frequently caused by biological activity in the clarifier
resulting in the release of micro gas bubbles which attach to the sludge
particles. One of the most frequent causes of a rising sludge is denitrifica-
tion in the secondary clarifiers. The denitrification process releases
nitrogen gas and carbon dioxide which causes the sludge to float. No degree
of increased clarifier sizing or decreasing the clarifier surface overflow
rate will compensate for a rising sludge. The cause of the denitrification in
the secondary clarifiers must be eliminated for the wastewater treatment plant
to meet standards.
Carbonaceous BOD Removal - This is the biological conversion of carbonaceous
organic matter in wastewater to cell tissue and various gases and by-products.
In the conversion it is assumed that nitrogen present in the various compounds
is converted to ammonia. High carbonaceous BOD values will result in effluent
violations.
Denitrification - The biological process by which nitrate is converted into
nitrogen and other gaseous end products. When denitrification occurs in the
secondary clarifiers the result is a rising sludge and effluent violations.
F/M Ratio - The food to mass ratio. This is a ratio of food substrate (BOD)
to biological mass (MLSS) which is used as a control parameter for determining
the organic loading rate to a biological treatment system. A high F/M ratio
means that oxygen uptake rates will be high, biological metabolic rates will
be high, and in the absence of excess oxygen, obligate aerobic bacteria will
be removed. A low F/M ratio generally results in high dissolved oxygen
concentrations and may result in the selection of bulking bacteria in a
municipal wastewater treatment system. In the semi-aerobic process high F/M
ratios are intentionally maintained in the first bay of the aeration tank in
order to maintain anaerobic or anoxic conditions necessary to select against
bulking bacteria.
Mixed Liquor Suspended Solids - (MLSS) The mixed liquor suspended solids or
mixed liquor volatile suspended solids are a measure of the amount of biomass
present in the aeration system. For most conventional activated sludge
systems, this concentration is approximately 1,200 to 3,000 milligrams per
liter (mg/1).
Nitrification - The two-stage biological process by which ammonia or total
kjeldahl (TKN) nitrogen is first converted to nitrite then to nitrate.
Nitrification is the necessary first step in the nitrification/denitrification
cycle. The goal is to convert ammonia into nitrates and ultimately into
gaseous end products.
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Over-pumping - This is the process by which the sludge inventory in the
secondary clarifiers is held to a rainimim in order to place the bulk of the
biomass back in the aeration system. Over-pumping of the clarifier sludge is
necessary when there is the potential for denitrification to occur in the
secondary clarifiers or where mixed liquor suspended solids in the aeration
basins must be held at a high concentration. A well-designed clarifier will
permit over-pumping on a routine basis by eliminating rat-holing, the
phenomenon by which water channels through the sludge blanket leaving behind
the solids. Channeling is minimized by providing slow agitation and hydraulic
scouring devices in the sludge pumping system. These devices are used in
circular clarifiers. Rectangular clarifiers generally use a chain and flight
mechanism which drags the sludge down to a sludge sump located at the
discharge end of the rectangular clarifier. The chain and flight sludge
mechanism is generally inefficient where over-pumping is required.
Surface Overflow Rate - (SOR) The surface overflow rate is one of the critical
design parameters for sizing a clarifier. The dimensions for the surface
overflow rate parameter are gallons per day square foot (gpd/d. ft^) of
clarifier surface. High surface overflow rates generally result in loss of
solids from the secondary clarifiers. Ten States Standards cites a surface
overflow rate of 1,200 gallons per day per square foot of clarifier surface
area as a good design maximum for conventional activated sludge processes.
However, due to the fact that sludges produced from nitrification processes
are generally poor settling, Ten States recommends a surface overflow rate of
800 gallons per day per square foot of surface area for nitrifying sludges.
For this briefing paper the general range of 700 to 1000 gallons per day per
square foot was selected as a conservative design criteria.
Sludge Volume Index - (SVI) The sludge volume index is expressed as the volume
in mils per gram of waste activated sludge after the mixed liquor has been
allowed to settle for 30 minutes under quiescent conditions. A low SVI is
indicative of a well-flocculated, poor-settling sludge. A high SVI is
indicative of a bulking, dispersed poor-settling sludge. Sludges with SVIs in
the range of 50 to 100 exibit excellent settling characteristics. Sludges
with SVIs in the range of 100 to 150 are generally transitional sludges with
fair to good settling characteristics. Sludges with SVIs in the range of 150
to 200 are characterized as bulking sludges as indicated by the poor settling
characteristics in the secondary clarifier and poor dewatering characteristics
in the sludge handling process.
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2. BRIEFING PAPER ASSUMPTIONS
The analysis contained in this briefing paper is based on two key
factors. These factors include wastewater flows and loads and NPDES permit
limits for the Southerly and Jackson Pike Wastewater Treatment Plants.
Alternative process trains were conservatively selected to meet applicable
1988 7-day and 30-day discharge limits.
A separate briefing paper, prepared for the EIS, documents the
development of wastewater flows and loads. Table 2-1 presents the EIS flows
and loads.
The average design flow for Jackson Pike will be held at 70 MGD, and the
peak design flow will held at 100 MGD. This results in an additional 18 MGD
at average flow and 32 MGD at peak flow being diverted to Southerly. Section
3.1.2.3 discusses the reasons for limiting the flows at Jackson Pike. Table
2-2 presents the actual flows and loadings which would be processed by each
plant. These flows and loadings are used to determine facility sizes in
Section 3.1.2.
Tables 2-3 and 2-4 provide a summary of the permit limitations for the
Jackson Pike and Southerly WWTPs. These were taken from Ohio EPA Permit No.
4PFOOOOO*GD (Jackson Pike) and 4PF00001*HD (Southerly). As noted on the
attached tables, the effluent characteristics are segregated by time of year
as well as by 30-day and 7-day limits. In addition to the concentration
limits, a mass loading limit based on an effluent loading of 60 MGD from
Jackson Pike and 120 MGD from Southerly are included. Table 2-5 is an
estimate of the one-plant permit limitations. These are based on the
assumption that the water quality impacts to the Scioto River will be the
limiting factor in the event the Southerly wastewater treatment plant is
expanded. Therefore, the concentration limitations were derived from those
assigned to the Southerly treatment plant. Mass loading limits were derived
by adding the flows of the Jackson Pike and Southerly plant together and
converting them to a mass basis.
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TABLE 2-1. 2008 PROJECTED FLOWS LOADS
Tributary to Jackson Pike
BOD (Ib/day) 141,600
TSS (Ib/day) 161,600
TKN (Ib/day) 18,532
Average Flow (MGD) 88
Peak Flow (MGD) 132
Tributary to Southerly
BOD (Ib/day) 126,600
TSS (Ib/day) 121,300
TKN (Ib/day) 16,570
Average Flow (MGD) 66
Peak Flow (MGD) 99
Total From Planning Area
BOD (Ib/day) 268,200
TSS (Ib/day) 282,900
TKN (Ib/day) 35,102
Average Flow (MGD) 154
Peak Flow (MGD) 231
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TABLE 2-2. ACTUAL FLOWS AND LOADS TO BE TREATED AT EACH FACILITY
Jackson Pike
• Flow (MGD)
• CBOD5 (Ib/day)
• TSS (Ib/day)
• TKN (Ib/day)
Southerly
• Flow (MGD)
• CBOD5 (Ib/day)
• TSS (Ib/day)
• TKN (Ib/day)
Average
70
112,600
128,500
14,740
84
155,600
154,400
20,360
Peak
100
107,300
122,400
14,040
131
160,900
160,500
21,060
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TABLE 2-3. PERMIT LIMITATIONS - JACKSON PIKE
Effluent Characteristics
C-BOD5
(June-Oct)
(Nov-Apr)
(May)
Suspended Solids
(June-Oct)
(Nov-Apr)
(May)
Ammonia (N)
(June-Oct)
(Nov-Apr)
(May)
Concentration
(mg/1)
30-day 7-day
8.0
20.0
13.0
16.0
30.0
26.0
1.0
5.0
2.5
12.0
30.0
19.5
24.0
45.0
39.0
1.5
7.5
3.75
Mass Loading
(Ibs/d)
30-day 7-ds
3,995 5,993
9,988 14,980
6,492 9,737
7,990 11,986
14,980 22,471
12,984 19,474
499
2,497
1,247
748
3,744
1,872
* Mass limits based on 60 MGD effluent loading
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TABLE 2-4. PERMIT LIMITATIONS -
Concentration
(mg/1)
Effluent Characteristics 30-day 7-day
C-BOD5
(June-Oct) 8.0 12.0
(Nov-Apr) 25.0 40.0
(May) 13.0 19.5
Suspended Solids
(June-Oct) 16.0 24.0
(Nov-Apr) 30.0 45.0
(May) 26.0 39.0
Ammonia (N)
(June-Oct) 1.0 1.5
(Nov-Apr) 5.0 7.5
(May) 2.0 3.0
* Mass limits based on 120 MGD effluent loading
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SOUTHERLY
Mass Loading*
(Ibs/d)
30-day 7-day
7,990 11,985
24,968 39,950
12,984 19,474
15,979 23,969
29,962 44,942
25,967 38,951
999 1,498
4,994 7,491
1,998 2,996
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TABLE 2-5. ESTIMATED ONE PLANT PERMIT LIMITATIONS
Concentration Mass Loading"
(mg/1) (Ibs/d)
Effluent Characteristics 30-day 7-day 30-day 7-day
C-BOD5
(June-Oct) 8.0 12.0 12,010 18,014
(Nov-Apr) 25.0 40.0 37,530 60,048
(May) 13.0 19.5 19,516 29,273
Suspended Solids
(June-Oct) 16.0 24.0 24,019 36,028
(Nov-Apr) 30.0 45.0 45,036 67,554
(May) 26.0 39.0 39,031 58,547
Ammonia (N)
(June-Oct) 1.0 1.5 1,501 2,252
(Nov-Apr) 5.0 7.5 7,506 11,259
(May) 2.0 3.0 3,002 4,507
* Mass limits based on 180 MGD effluent loading
1. No one-plant permit presently exists. Mass loadings were derived from
180 MGD flow and Southerly concentration limits.
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For the purposes of this briefing paper, it will be assumed that a
treatment train would be deficient if it would be unable to meet either the
30-day or 7-day concentration limit or the 30-day or 7-day mass loading limit.
It is understood that mass limits can be modified if the new loading does not
negatively impact receiving water quality. Temperature considerations as they
impact such variables as nitrification rates were evaluated based on the most
stringent occurrence of those temperatures. For example, nitrification was
evaluated utilizing a sewage temperature of 12°C to meet a May ammonia limit.
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3. PROCESS EVALUATION
This section describes and evaluates the biological process alternatives
proposed in the facility plan. The alternatives are evaluated based on
technical criteria, environmental criteria, and system costs.
3.1 PROCESS DESCRIPTION
The semi-aerobic (SA) and the trickling filter/activated sludge (TF/AS)
biological processes were evaluated for these alternatives:
• Southerly Two-Plant
• Jackson Pike Two-Plant
• Southerly One-Plant
The semi-aerobic process is a modified form of the activated sludge
process. The process consists of a non-aerated reaction zone ahead an aerated
activated sludge zone. The non-aerated zone may be anoxic (nitrates are
present), anaerobic (no nitrates or oxygen present), or a combination of both.
The purpose of the anaerobic zone is to function as a selector mechanism
providing an environment which discourages proliferation of filamentous
organisms and thereby controls bulking sludge. The anaerobic zone may change
to anoxic depending on the level and concentration of nitrates in the
wastewater. Denitrification occurs in the anoxic zone. Denitrification is a
process by which nitrates are converted into nitrogen gas.
The only physical differences between the semi-aerobic process and the
conventional activated sludge process is the addition of an internal mixed
liquor recycle loop and two baffles in the first bay of the aeration tanks.
The internal recycle loop is used to bring nitrates back to the anoxic zone
and thus cause denitrification to take place. The baffles are incorporated
into the design to prevent backmixing from the aerated zone to the anaerobic
zone.
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In reviewing full-scale operational data from the Southerly plant as well
as an evaluation of nitrification rates at both Southerly and Jackson Pike, it
is evident that the semi-aerobic process proposed by the city is in effect
similar to the conventional activated sludge process with the exception of the
internal mixed liquor recycle loop and the addition of two baffles in the
first bay of the aeration tanks. Given these exceptions, a conventional
activated sludge system can be operated as a semi-aerobic process simply by
reducing the amount of aeration provided in the first bay of the system. If
one takes Chis reasoning one step further and adds an internal recycle pumping
system (estimated cost $10,000 per aeration tank), the result is a semi-
aerobic process minus two 23x15 foot concrete baffles. For this reason, it
was assumed that the semi-aerobic process and the activated sludge process
were in effect identical and would be evaluated on that basis.
The trickling filter/activated sludge process is comprised of roughing
trickling filters followed by aeration tanks. The trickling filters are
designed to remove 40 percent of the BODr. They function in the same manner
as the anaerobic/anoxic zone of the semi-aerobic process in that they select
for non-filamentous bacteria. The aeration tanks that follow the filter
remove the remaining BODr and provide the required nitrification. An internal
recycle loop can be provided back to the trickling filters to initiate
denitrification there.
Slightly reduced aeration tank capacity and aeration energy is required
since the trickling filter has the ability to dampen peak biological loads and
thus minimize the amount of aeration time needed to achieve complete
biological oxidation.
The following sections present design criteria and recommended process
sizing for each alternative.
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3.1.1 Design Criteria
The biological process design criteria are listed in Table 3-1. These
criteria were derived from pilot data provided by the city's consultant, the
Ten States Standards (Recommended Standards for Sewage Works, 1978 Edition,
Health Education Service Incorporated, Albany, New York 12224), and USEPA
criteria (Innovative and Alternative Technology Manual, EPA-430/9-78-009,
1978). The range of acceptable operating conditions given in Table 3-1
defines the critical regions for the aeration, trickling filter, and final
clarification processes. In the absence of more extensive full-scale piloting
data, it is assumed that violation of these criteria would result in
inadequate treatment of the wastewater received at Jackson Pike or Southerly
which would result in effluent violations.
3.1.1.1 Aeration Basins
The aeration process listing in Table 3-1 includes evaluation criteria
for the hydraulic retention time in the aeration basin, F/M ratios in the
first bay as well as the overall F/M ratio of the aeration basin, design mixed
liquor suspended solids concentrations, minimum solids retention times, and a
recommended ratio of oxygen uptake rates to dissolved oxygen (OUR/DO).
A minimum hydraulic retention time in the aeration basin of 4.5 hours is
limited to the final 7 bays of the plug flow reactor for the semi-aerobic
process. This datura was taken from the Southerly SBR Nitrification Study
conducted by the city's consultant (January 1987). The hydraulic residence
time in the Project 20 full-scale semi-aerobic pilot study conducted at the
Southerly waste treatment plant typically ranged from 5 to 8 hours. The use
of a shorter residence time in the aeration basin for the trickling filter
process is based on the fact that a roughing filter has the ability to dampen
or attenuate peak biological loads, thus minimizing the amount of aeration
time required to achieve complete biological oxidation.
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TABLE 3-1. BIOLOGICAL PROCESS DESIGN CRITERIA
Process Parameter Range
Aeration Hydraulic Retention Time 4.75-SA, AS
(HRT, hrs) Minimum 3-TF
F/M First Bay 5
Overall 0.13-0.17
MLSS (mg/1)
Southerly 3500
Jackson Pike 2500
Solids Retention Time (days)
Southerly 9.9
Jackson Pike 8.7
OUR/D.O. 250-500
Roughing Trickling Hydraulic Loading Rate 1400-4600
Filter (gpd/ft2)
Organic Loading Rate 100-500
(Ib BOD/d.1000 ft3)
Clarifiers Surface Overflow Rates 400-1000
(gpd/ft2)
Solids Loading Rates 20-50
(Ib/d. ft2)
Southerly SBR Nitrification Study, Orris Albertson, URS Dalton
2"The Control of Bulking Sludges", JWPCF, April 1987
Source
SBR Report1
City of Columbus
Comment Letter
Control of Bulking
Sludge2
USEPA3 >4
USEPA3
USEPA3
USEPA3
, January 1987
^"Innovative and Alternative Technology Manual", EPA 430/9-78-009, 1978
^"Wastewater Treatment Plant Design", WPCF, 1977
^No MLSS are provided for the combined plant option because the
studies have not been run for that wastewater blend.
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The selection of an F/M ratio of 5 in the first bay of the semi-aerobic
system is based on correspondence with Mr. Orris E. Albertson, Process
Consultant to the city's consultant. Mr. Albertson also stated in an article
published in the April 1987 Journal of the Water Pollution Control Federation
that the maintenance of a high F/M ratio in the initial contact basin of a
semi-aerobic system was required to maintain the anaerobic and anoxic
conditions necessary to select against bulking bacteria. This high F/M ratio
would be realized in both the semi-aerobic and activated sludge options. It
is assumed that the trickling filter option would greatly reduce this F/M
ratio due to the attenuating effect the upstream roughing filter would have on
carbonaceous BOD loadings. An overall aeration basin F/M value of 0.13 to
0.17 would be consistent for a well operated nitrifying activated sludge
system.
The mixed liquor suspended solids concentrations of 3,500 mg/1 for
the Southerly plant and 2,500 mg/1 for the Jackson Pike plant were
derived from SBR studies conducted by the city's consultant. It is assumed
that mixed liquor concentrations of the same magnitude would be required for a
conventional activated sludge system. The primary reason for the higher mixed
liquor suspended solids in the Southerly aeration basin is the low nitrifica-
tion rates observed at that plant. Increasing the MLSS to 3,500 mg/1 allows
nitrification to proceed with fewer aeration basins than would be required at
2,500 mg/1. The Jackson Pike WWTP experiences nitrification rates well within
the range of most sewage treatment facilities.
The cause of lower nitrification rates at the Southerly plant is most
likely due to toxicity of some non-conventional pollutants present in the
Southerly raw wastewater. Nitrification rates for the Jackson Pike wastewater
treatment system are well within the range of nitrification rates realized in
North American municipal treatment facilities.
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The significance of the oxygen uptake rate to dissolved oxygen ratio
(OUR/DO) has been cited by Mr. Orris Albertson as necessary for the control of
bulking sludge organisms in municipal treatment facilities. In his paper, Mr.
Albertson indicates that "The best control of bulking sludges is provided by
both reactor compartmentalization and by DO control in each of the
compartments. Often in practice, either will provide the necessary SVI
control; but the maximum control will be available when both a high F/M
gradient is present and DO control as a function of time for each compartment
is provided." Mr. Albertson further states that "Regardless of whether the
initial contact zone is aerated or unaerated a sufficiently high OUR/DO ratio
will ensure both SVI control and enhance phosphorus removal. The suggested
minimum OUR/DO ratio is greater than 250 to 1 and preferably as high as 500 to
1." Under conditions of high F/M ratios, Mr. Albertson contends that the
biological cell will uptake organic material and release soluble phosphates
given that the DO gradiant across the slime layer of the cell is less than
0.5 mg per liter. Under endogenous conditions, such as occur in the final
zones of the aeration basin, soluble phosphate uptake occurs as well as the
release of endogenous decay products resulting in a well-flocculated mixed
liquor leaving the aeration basin. It should be noted that these conditions
can be achieved in a conventional activated sludge aeration basin by the use
of compartmentalization and reducing the blower capacity in the initial stages
of the aeration tanks. This condition is further enhanced by increasing the
mixed liquor suspended solids and providing for an internal mixed liquor
recycle loop.
3.1.1.2 Trickling Filters
The design criteria for roughing trickling filters which are followed by
activated sludge systems is considerably higher than those for trickling
filters followed by clarification. Hydraulic loading rates ranging from 1,400
to 4,600 gallons per day per square foot of surface area are considered good
design criteria. Organic loading rates in the range of 100 to 500 pounds of
BOD per day per 1,000 cubic feet volume would also provide adequate capacity
for a roughing trickling filter. The trickling filters, when operated in this
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condition, act as the initial zone or anaerobic/anoxic zone of the aeration
basin under the semi-aerobic or activated sludge options. The roughing
trickling filters would reduce the volume of aeration basin required and
effectively assist in control of sludge bulking.
3.1.1.3 Clarifiers
Given the fact that the three previously selected biological treatment
processes (semi-aerobic, conventional activated sludge, and trickling filter
followed by activated sludge) all can act as effective selectors against
bulking organisms, it was assumed that SVIs would generally be in the range of
70 to 150. Given this SVI range, there are two critical design factors which
must be considered when selecting and sizing final clarifiers. These are
surface overflow rates (gallons per day per square foot surface area) and
solids or floor loading rates (pounds of suspended solids per day per square
foot). The city's consultant has selected conservative surface overflow rates
for their final clarifiers. These are generally in the range of 470 for
average flows and 800 for sustained peak flows. Mr. Richard Brenner, USEPA
Cincinnati, indicated that conservative design criteria for average flow rates
would be in the range of 500 to 550 with peak sustained surface overflow
loading rates set at 900 to 950. For the purposes of this evaluation, a. range
of 400 for average flow and 1,000 for sustained peak flow will be used.
The city's consultant selected solids or floor loading rates for their
clarifiers in the range of 18 to 23 pounds per day per square foot for
average flows and 29 to 36 pounds per day per square foot for peak flows. A
solids loading criteria of 20 to 50 pounds per day per square foot is cited in
the USEPA Innovative and Alternative Technology Manual. Rectangular
clarifiers should generally be sized on the lower end of this solids loading
rate. Circular clarifiers with hydraulically assisted sludge removal devices
can easily accommodate the higher solids loading rates without causing sludge
channeling or solids entrainraent. However, as pointed out by the city's
consultant, SVIs are also a limiting factor in determining an acceptable
solids loading rate. Therefore, the Daigger and Roper Clarification Tank
Design and Operation Diagrams will also be used in this evaluation.
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3.1.2 Recommended Sizing
Based on the previously stated process design criteria and the 2008
projected flows and loads given in Table 2-1 of this briefing paper, two
biological treatment trains (i.e. semi-aerobic and trickling filter/activated
sludge) were evaluated for the following alternatives:
• Southerly Two-plant
• Jackson Pike Two-plant
• Southerly One-plant
A critical assumption in this evaluation is that the projected flows and
loads given in Table 2-1 will permit the plants to treat all anticipated dry
weather flows plus some additional inflow and infiltration during wet weather
events to a peak design flow of 100 MGD for Jackson Pike, 131 MGD for
Southerly two-plant, and 231 MGD for a Southerly one-plant alternative.
BOD and total suspended solids loadings developed for this briefing paper
were similar to those presented in the facility plan. Total kjeldahl nitrogen
and total phosphorus loadings presented in the facility plan were used in this
process evaluation (Table 2.1). It was further assumed that the increase in
flow due to the application of a 1.5 peaking factor would have little or no
effect on the mass daily loading of BOD, total suspended solids, or nitrogen.
Tables 3-2 through 3-7 document the results of this briefing paper
analysis relative to the sizing and performance of the various biological
treatment processes for Southerly and Jackson Pike. All previously stated
design and loading criteria were used to derive the data presented in these
tables.
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3.1.2.1 Southerly Two-Plant Semi-Aerobic
Table 3-2 is a summary of the Southerly two-plant semi-aerobic or
activated sludge options. The existing six aeration basins in the west train
would be utilized with the addition of an internal recirculation pump and
baffles for the semi-aerobic option. Four of the existing center train
aeration basins would be used with the addition of two new 26 foot by 900 foot
by 15 foot sidewall depth aeration basins. Given these conditions, average
and peak aeration times fall well within the design parameters cited in Table
3-1. In terms of final clarification, the existing clarifiers would be
replaced with six new 190-foot diameter circular clarifiers fitted with
hydraulic sludge removal devices, flocculation chambers, and associated piping
and an internal mixed liquor recycle system. The addition of these six
190-foot diameter units place the clarifiers well within the critically
designed surface overflow rates of 400 to 800 gallons per day per square foot
of surface area established by the city's consultant. The solids loading
rates based on a mixed liquor suspended solids of 3500 mg per liter fall well
within process evaluation criteria. Under peak hydraulic loading conditions
the solids loading rates would exceed design criteria established in the
facility plan. Given the fact that circular clarifiers will be used in this
application, it is unlikely that a peak loading of 38 pounds per day per
square foot would overload the proposed clarifiers. The Daigger and Roper
Diagram shows that the clarifiers could operate efficiently up to an SVI of
165 ml/g.
3.1.2.2 Southerly Two-Plant Trickling Filter
The critical design data for the Southerly two-plant trickling filter
option is presented in Table 3-3. Any evaluation of trickling filters at the
Southerly plant requires an understanding of the existing plant layout and
related logistical problems. There is inadequate space between the existing
primary clarifiers and aeration basins to install the proposed 110-foot
diameter trickling filters. Due to this limitation it was assumed that the
trickling filters would be located in an area remote to those processes and
that primary effluent would be pumped to the trickling filter and discharged
from the trickling filter to the influent end of the aeration basin by gravity
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TABLE 3-2. SOUTHERLY PROCESS DESCRIPTION - TWO
West Train Center
Flow (Design)
Average (MGD) 42 42
Peak (MGD) 65.5 65
Aeration
Tankage
New — 2@26'x900
Existing 6@26 ' x900 'x!5 ' SWD 4@26'x900
HRT (hrs)
Average 9.00 9
Peak 5.77 5
Clarification
Tankage
New 6(3190' dia.x!5' SWD
Existing
Surface Overflow
Rate (gpd/ft2)
Average 490
Peak 770
Solids Loading
Rate (Ib/d. ft2)
Average 25
Peak 38
C-23
PLANT SEMI-AEROBIC, AS
Train Total
84
.5 131
'xl5'SWD 2
'xlS'SWD 10
.00
.77
6
"
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TABLE 3-3. SOUTHERLY PROCESS DESCRIPTION - TWO PLANT TF/AS
Flow (Design)
Average (MGD)
Peak (MGD)
West Train
46
71
Center Train
38
60
Total
84
131
Trickling Filters
Filters 2@110 '0x22'ht,
Hydraulic Loading
Rate (gpd/ft2)
Average 2420
Peak 3740
Organic Loading Rate
(Ib.BOD/d. 1000 ft3)
Average 160
Peak 160
Aeration
Tankage
New —
Existing 5
HRT (hrs)
Average
Peak
6.85
4.43
2@110'0x22'ht.
2000
3160
130
130
6.63
4.20
Clarification
Tankage
New
Existing
Surface Overflow Rate
(gpd/ft2)
Average 490
Peak 770
Solids Loading Rate
(Ib/d. ft2)
Average
Peak
25
38
6@190'dia.xl5'SWD
C-24
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conduits. These logistical problems while not insurmountable were taken into
consideration when evaluating the overall effect of the trickling filter
process as discussed in Section 4 of this briefing paper.
As indicated in Table 3-3, four 110-foot diameter by 22-foot high high-
rate roughing trickling filters were sized for the Southerly two-plant option.
Two trickling filters would service each of the existing treatment trains.
Hydraulic loading rates of 3,740 and 3,160 gallons per day per square foot of
trickling filter surface area are well within the design criteria limit of
4,600 gallons per day per square foot. The organic loading rates of 130 and
160 pounds BOD per day per 1,000 cubic feet of trickling filter volume are
well within the 100 to 500 range. Following the trickling filters, five of
the six existing aeration basins in the west train and four existing basins in
the center train would be used for aeration capacity. Although the hydraulic
retention times are considerably less than thoses cited for the semi-aerobic
or activated sludge systems, it is considered adequate for aeration following
roughing trickling filters.
Final clarification consists of six 190-foot diameter clarifiers with
resulting surface overflow rates in the range of 490 gallons per day per
square foot under average conditions and 770 gallons per day per square foot
under peak conditions. Solids loading rates range from 25 pounds per day per
square foot at average flow to 38 pounds per day per square foot at peak flow.
3.1.2.3 Jackson Pike Two-Plant Semi-Aerobic
Table 3-4 summarizes the design criteria for the Jackson Pike semi-
aerobic and activated sludge process trains. The assumption used throughout
this briefing paper is that the Jackson Pike plant is hydraulically limited to
100 MGD. This assumption is based on information from the city and their
consultant. The average flow to Jackson Pike was limited to 70 MGD based on
the capacity of the existing aeration tanks. Average flows in excess of
70 MGD and peak flows in excess of 100 MGD will be diverted to the Southerly
WWTP.
C-25
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TABLE 3-4. JACKSON PIKE PROCESS DESCRIPTION - SEMI-AEROBIC, AS
Flow (Design)
Average (MGD)
Peak (MGD)
Aeration
Tankage
New
Existing
HRT (hrs)
Average
Peak
Clarification
A-Train
42
60
6(?26lx9001xl5lSWD
9.00
6.30
Tankage
New —
Existing 8@153'x60'x!2.5'SWD
Surface Overflow Rate
(gpd/ft2)
Average 570
Peak 820
B-Train
28
40
Total
70
100
4(326'x900'xl5'SWD
9.00
6.30
10
Solids Loading Rate
(Ibs/d. ft*)
Average
Peak
20
29
2@153'x60lxl2.5'SWD
4
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The semi-aerobic system would utilize 6 existing aeration basins in the A
train. In the B train the 4 existing aeration basins would be utilized. A
flow split of 60 percent to the A Train and 40 percent to the B Train would be
employed. Under both conditions, hydraulic retention times are well within
the limits established in the evaluation criteria. These criteria were
established during the SBR and piloting studies utilizing Jackson Pike primary
effluent. As previously stated, the nitrification rates in the Jackson Pike
studies have been approximately 300 percent higher than those reported for
Southerly. Given these conditions, the hydraulic retention time cited in
Table 3-4 is considered adequate when operating at a MLSS of 2500 mg/1.
In evaluating final clarification for Jackson Pike, the selected option
includes rehabilitating the existing 12 clarifier units and adding 2 new
rectangular clarifiers (153-foot by 60-foot by 12.5-foot sidewall depth) to
the B-train. The addition of 2 new rectangular clarifiers would provide
Jackson Pike with a combined surface overflow area of 128,000 square feet.
The facility plan recommended demolishing the existing clarifiers and
installing four new 200-foot diameter circular clarifiers. This would provide
the facility with 126,000 square feet of final clarifier surface area.
Surface overflow rates and solids loading rates would be essentially identical
for the rectangular clarifiers versus the new circular clarifiers. A
discussion of final clarifier utilization for both Southerly and Jackson Pike
is presented in Section 4.2 of this briefing paper.
3.1.2.4 Jackson Pike Two-Plant Trickling Filter/Activated Sludge
The trickling filter/activated sludge option design criteria for the
Jackson Pike WWTP is summarized in Table 3-5. The design criteria for
aeration and final clarification are essentially the same as those described
under the Jackson Pike serai-aerobic and activated sludge options. Two new
110-foot diameter by 22-foot high and two new 90-foot diameter by 22-foot high
trickling filters would be added to the process treatment trains. Critical
design conditions in terms of hydraulic loading and organic loading are well
within criteria cited in Table 3-1. One limitation which impacts the
selection of trickling filters for Jackson Pike is space. While the evaluation
027
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TABLE 3-5. JACKSON PIKE PROCESS DESCRIPTION - TF/AS
Flow (Design)
Average (MGD)
Peak (MGD)
Trickling Filters
A-Train
42
60
Filters 2@110'0x22'ht.
Hydraulic Loading
Rate (gpd/ft2)
Average 2210
Peak 3160
Organic Loading Rate
(Ib. BOD/d.1000 ft3)
Average 120
Peak 120
Aeration
Tankage
New
Existing 6
HRT (hrs)
Average 9.00
Peak 6.30
Clarification
B-Train
28
40
2(390'0x22'ht.
2200
3140
120
120
9.00
6.30
Total
70
100
10
Tankage
New
Existing 8@153'x60'xl2.5'SWD
Surface Overflow Rate
(gpd/ft2)
Average 570
Peak 820
Solids Loading Rate
(Ib/d. ft2)
Average
Peak
20
29
2@153'x60'xl2.5'SWD
4@153'x60'xl2.5'SWD
510
730
18
26
2
12
C-28
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of critical design criteria indicate that four units would be adequate,
limited available area would make siting difficult.
3.1.2.5 Southerly One-Plant Semi-Aerobic
The critical design criteria for a one-plant semi-aerobic option are
presented in Table 3-6. Under the one-plant option, the existing center and
west train would handle an average flow of 88 MGD with a peak flow of 132 MGD.
With the increased hydraulic loading, it will be necessary to construct a new
east train capable of handling an average of 66 MGD with peak sustained loads
of 99 MGD. This would include use of ten existing aeration basins at the
center and west trains with the construction of two new 26-foot by 900-foot by
15-foot sidewall depth basins on the center train. The new east train would
contain nine 26-foot by 900-foot by 15-foot sidewall depth aeration basins.
Final clarification would include six new 200-foot diameter circular
clarifiers for the center and west train and four new 205-foot diameter
circular clarifiers for the east train for a combined facility clarifier
surface area of 320,360 square feet. Given the amount of clarifier capacity,
both the surface overflow rates and solids loading rates are within design
criteria.
3.1.2.6 Southerly One-Plant Trickling Filter/Activated Sludge
The trickling filter/activated sludge option for a Southerly one-plant
operation is presented in Table 3-7. The trickling filters would consist of
four 115-foot diameter units for the center and west trains and two 115-foot
diameter units for the east train. Under sustained peak hydraulic loading,
the hydraulic loading criteria is within the 4,600 gallons per day per square
foot of surface area for all trains. Organic loadings are within the range of
100 to 500 pounds of BOD per day per thousand cubic feet of reactor volume.
All other aeration and clarification criteria fall within the critical design
criteria for the one-plant option.
C-29
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TABLE 3-6. SOUTHERLY PROCESS DESCRIPTION - ONE-PLANT SEMI-AEROBIC AND AS
Center and West Train East Train (New)
Flow (Design)
Average(MGD)
Peak(MGD)
Aeration
Tankage
New
Existing
HRT (hr)
Average
Peak
Clarification
88
132
66
99
2@26'x900'xl5'SWD
10(326' x900'xl5'SWD
8.59
5.73
Tankage
New
Existing
6(3200'0x15'SWD
Surface Overflow Rate
(gpd/ft2)
Average 470
Peak 700
Solids Loading Rate
(pounds/d.ft2)
Average 23
Peak 35
9@26'x900'xl5'SWD
8.58
5.72
4@205'0xl5'SWD
500
750
25
37
Total
154
231
11
10
10
C-30
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1
1
1
1
1
1
1
1
Ml
1
1
1
1
1
1
1
TABLE 3-7. SOUTHERLY PROCESS DESCRIPTION - ONE-PLANT TF/AS
West Train Center Train East Train
Flow (Design)
Average (MGD) 50 42 62
Peak (MO)) 75 63 93
Trickling Filter
Filters (New) 2@1 15 ' 0x22 ' ht . 2@115'0x22'ht. 2@115'0x22'ht.
Hydraulic Loading
Rate (gpd/ft2)
Average 2410 2020 2990
Peak 3610 3030 4480
Organic
(Ib.BOD/d. 1000ft3)
Average 150 120 180
Peak 150 120 180
Aeration
Tankage
New 6@900'x26'xl5'SWD
Existing 5@900'x26'xl5'SWD 4@900 ' x26 ' x!5 ' SWD
HRT (hrs)
Average 6.29 6.00 6.10
Peak 4.19 4.00 4.06
West and Center Train East Train
Clarification
Tankage
New 6(3200' 0x15 'SWD 4@200 ' 0x15 ' SWD
Existing
Surface Overflow Rate
(gpd/ft2)
Average 490 500
Peak 730 750
Solids Loading Rate
(pounds/d.ft2)
Average 24 25
Peak 36 37
C-31
Total
154
231
6
6
9
10
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Final clarification would include six new 200-foot diameter clarifiers
for the west and center trains and four new 200-foot diameter units for the
east train.
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3.2 TECHNICAL EVALUATION
The previously described treatment options were evaluated in terms of I
their reliability and flexibility. Reliability is measured in terms of
potential loss of treatment system components as well as the impact of I
toxicity on the biological treatment process. System flexibility is discussed
in terras of response to mass loadings as well as upsets within the system. •
3.2.1 Reliability —
A summary of system reliability for the biological process options is ™
presented in Table 3-8. The semi-aerobic and activated sludge processes are ^
evaluated with respect to aeration basin hydraulic retention time. Trickling |
filters are evaluated with respect to organic and hydraulic loading rates.
Final clarification is evaluated with respect to surface overflow rates and
solids loading criteria.
The analysis of system reliability considered that one of the system
components was out of service. The components remaining in-service would be
required to process the influent flow. Table 3-8 presents the impact on the
process design criteria of processing average and peak flow through the system
with one unit out of service. Under conditions where system components were
separated into two parallel treatment trains, or in the case of Southerly one-
plant where there are three parallel treatment trains, the worst case scenario
was represented by the loss of one essential component in each of the parallel
trains. The reliability evaluation may also be interpreted as a surge in
hydraulic or mass loadings, where all units are operative, due to brief
intervals of raw wastewater flows or loads above those projected in Table 2-1.
The system reliability data for the Jackson Pike semi-aerobic and
trickling filter/activated sludge alternatives is contained in the first two
columns of Table 3-8. For the aeration basin capacity, it was assumed that
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TABLE 3-8. SYSTEM RELIABILITY
PARAMETER
Aeration
Hydraulic Retention
Time (hrs)
Average
Peak
Trickling Filter
Hydraulic Loading
Rate (gpd/ft2)
Average
Peak
Organic Loading
Rate (Ib BOD/d/1000ft3)
Average
Peak
Clarification
Surface Overflow
Rate (gpd/ft2)
Average
Peak
Solids Loading
Rate (lb/d/ft2)
Average
Peak
Jackson Pike
(2-Plant)
SA TF/AS
6.75 6.75
4.75 4.75
3150
4500
180
180
610 610
930 930
22 22
33 33
Southerly
(2-Plant)
SA TF/AS
7.50 5.00
4.80 3.15
2950
4590
190
190
590 590
920 920
29 29
46 46
Southerly
(1-Plant)
SA TF/AS
7.15 4.50
4.76 3.00
2970
4450
235
235
670 660
1000 990
33 33
50 49
NOTE: This table assumes one component (aeration basin, trickling filter,
or clarifier) is removed from service for repair or maintenance. The
resulting impact on the process design criteria is identified.
C-33
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one of the four aeration basins in the B train was removed from service for an •
extended period of time leaving three functional basins in the B train; and |
one of the six basins in the A train was removed leaving five basins available
in the A train. The efficiency of either train should not be affected since I
the hydraulic retention times are still within design criteria listed in Table
I
The impact of removing one of the 110-foot diameter trickling filters from
service would cause the hydraulic loading rate to increase to 4,500 gallons
I
per day per square foot of surface area under peak flow conditions. This does —
not exceed the design criteria of 1,400 to 4,600. The organic loading rate •
would increase to 180 pounds of BOD per day per 1000 cubic feet of filter.
This is still within the design range of 100 to 500. I
The removal of one of the clarifiers in each train would not have a •
significant impact on the solids overflow or solids loading design criteria. ™
C-34
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Columns three and four of Table 3-8 show the impact of a loss of process
components at Southerly under a two-plant option. Removal of one of the six
aeration basins in either the west train or the center train would not cause •
the minimum hydraulic retention time to be violated. Removal of one of the
four trickling filters would not violate either the established maximum B
hydraulic or organic loading rates.
Removal of one of the six circular clarifiers would not result in a •
violation of the established design criteria. The solids loading rates would
be high (46 Ib/d/ft^); however, this should not be a problem for circular I
clarifiers if the SVI is not excessively high.
Columns 5 and 6 in Table 3-8 presents the system reliability evaluation
for the Southerly one-plant option. One of the aeration basins in each of the
three trains would be removed from service due to maintenance or mechanical
failure. For the semi-aerobic and TF/AS options, this would result in _
hydraulic retention times in the aeration basins within specified design |p
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criteria. Removal of one of the six trickling filters would not result in
violations of the established maximum hydraulic or organic loading rates.
In terras of clarifier capacity it was assumed that one of the circular
clarifiers would be removed from the west and center section and one from the
east section. Under these conditions, the surface overflow rate as well as
the solids loading rate under peak hydraulic loadings would approach the
critical limits of the design criteria; however, they would not violate them.
Once again, this should not be a problem for circular clarifiers.
In summary, all of the components under each alternative would be capable
of operating within the specified design criteria in the event that a unit was
removed from operation.
The second measure of system reliability is its ability to respond to
system upsets or toxicity problems. The semi-aerobic process provides
excellent capabilities to adjust to high ammonia loadings. Ammonia
concentrations will be monitored in the number 6 bay in each of the aeration
basins. Once ammonia concentrations above 2 mg/1 are found, the aeration in
Bay 2 will be activated as well as a general D.O. increase which will
enhance the nitrification rate. If this is not adequate to reduce NH^N to
1.0 mg/1, then the internal recycle pump will be shut down to increase the
real detention time. The internal recycle pump reduces nitrification capacity
due to the volume used for denitrification.
The roughing trickling filter acts as an anaerobic/anoxic aeration bay in
the semi-aerobic process. The filter reduces BOD loadings to the aeration
basins and effectively aids in the control of sludge bulking. Effluent
recycling from the aeration basins back to the trickling filters acts in much
the same way as the internal recycle of the semi-aerobic process. Aeration
basin effluent recycling would also cause denitrification to occur within the
trickling filters. Denitrification is vital during the summer months to
prevent a rising sludge in the final clarifiers. One significant limitation
of the trickling filter in cold climates is the tendency to ice. Under these
C-35
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conditions, loss of bio-mass as well as reduced process efficiency reduce the
effectiveness of the trickling filters.
Toxic effects will have a similar impact on the semi-aerobic and
trickling filter processes due to the common bacterial organisms used in
nitrification and denitrification. One source of toxicity to a nitrification
system can be slug loads of ammonia or TKN. Table 3-9 is a summary of Project
20 operating data for the month of February 1987. Project 20 is not being run
in a manner exactly similar to that proposed for the semi-aerobic process.
Nevertheless, its performance is indicative of the ability of the semi-aerobic
process to nitrify under winter conditions. The data in Table 3-9 includes
primary effluent ammonia concentrations for the west and center treatment
trains, final effluent ammonia concentrations for aeration basins 1 and 2
which represent the semi-aerobic process, and ammonia concentrations from the
remaining aeration basins which were operated in a conventional activated
sludge mode with reduced aeration in the initial bays of each basin.
The data indicate that both the semi-aerobic and activated sludge process
can meet 7-day and 30-day ammonia limits under cold weather conditions.
However, it should be noted that periodic peak loadings of ammonia such as
occurred on February 4, February 22, and February 24, resulted in bleedthrough
of high ammonia concentrations to the final effluent. Generally, it appears
that ammonia concentrations in the primary effluent in excess of 25 mg/1 would
result in violations of the 7-day and 30-day permit if they were sustained.
It is apparent from the Project 20 data that slug loads of ammonia will cause
effluent violations for both the semi-aerobic and activated sludge processes.
The trickling filter/activated sludge option would respond in a similar
fashion allowing bleedthrough of high influent ammonia loads. The source of
the high nitrogen load is most likely one or more industries within the
service area. As a result it is recommended that the sources of the high
ammonia loads be identified and be limited in the amount of TKN they are
allowed to discharge. Without such control, it would be impossible to
consistently meet the 1988 effluent limits for ammonia.
C-36
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TABLE 3-9. AMMONIA BREAK-THROUGH - SOUTHERLY
(Ammonia as N, mg/1)
Date
February
1
2
3
4
5
8
9
10
11
12
15
16
17
19
22
23
24
25
Primary Effluent
West
17
17
18
24
20
17
18
15
15
17
16
21
20
30
19
24
15
Center
15
14
16
24
19
15
17
15
14
14
21
20
30
18
25
15
SOURCE: Contract 20 Operational Data
Final Effluent
1 & 2
(Semi-Aerobic)
30-day
7-day
1.1
0.7
0.9
5.3
1.3
0.1
0.1
0.1
0.2
0.1
0.1
0.6
1.2
4.6
7.3
8.7
1.8
0.4
1.9
3.5
all others
(AS)
2.5
2.5
3.7
7.4
3.4
3.1
2.8
1.4
0.7
0.1
—
1.6
1.5
5.6
8.7
10.5
7.1
2.6
3.6
5.4
C-37
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The data in Table 3-10 summarizes reported pollutant concentrations in
the Jackson Pike and Southerly influent and presents inhibition levels of
these pollutants for various biological processes. Influent concentrations of
copper and zinc at the Columbus plants may be found at levels which can
inhibit the nitrification process. Copper and zinc could act as inhibitory
pollutants if the influent concentrations shown in Table 3-10 are carried
through the primary effluent and enter the biological treatment process. The
city of Columbus must consider controlling the level of inhibitory industrial
pollutants to prevent system upsets. An aggresive and well-monitored
industrial pretreatment program would be necessary to ensure the nitrification
process is protected from inhibitory and/or toxic effects of industrial
discharges.
3.2.2 Flexibility
System flexibility is defined as the ability of the system to expand or to
turn-down (respond to reduced flows or loads) its biological processes. It
will be necessary for the city of Columbus to control slug loads of ammonia
and TKN no matter which biological option or treatment plant option is
selected. Impacts can also be manifested in terms of loss of load. At the
present time, it is estimated that 35 to 45 percent of the BOD loading to
the Southerly plant originates with the Anheuser-Busch Brewery. The impacts
of losing this BOD loading are most directly felt in the first bay of the
semi-aerobic system. Mr. Albertson has indicated that in order to control
bulking, an OUR/DO ratio of at least 250-1 must be maintained. Under current
design conditions, the OUR/DO ratio is approximately 500-1. Given the loss of
all brewery waste for a sustained period, it can be assumed that a critical
OUR/DO ratio can be maintained. If the brewery wastes are the primary source
of the historical bulking problems at Southerly, the plant could operate in a
semi-aerobic or conventional activated sludge mode with little or no problems.
The second advantage of the semi-aerobic process in terms of responding
to periodic upsets is what Mr. Albertson has described as sludge memory. Most
activated sludge systems which have biological phosphorus removal capabilities
are able to respond in a linear fashion to organic loading upsets based on
C-38
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"8
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C-39
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sludge age. Assume the sludge age is maintained at 9 days for a 2-day period •
and the primary source of organic loading is removed from the system. The |
impact on the effluent would be comparable to the ratio of 2-9 or
approximately 22 percent loss of system efficiency. Under these conditions, I
the system would recover rapidly once the source of organic loading is placed
back into the system. The disadvantage of this type of activated sludge I
(i.e., one which demonstrates biological phosphorus removal), is that the
sludge yield in terms of pounds of sludge produced per pound of BOD destroyed •
is quite high. This is due to the fact that the elemental phosphorus I
percipitated from the system contributes to the total sludge volume. (Sentence deleted
I
3.3 ENVIRONMENTAL CRITERIA
One purpose for evaluating treatment alternatives and options is •
ultimately to ensure that the treatment plants meet their environmental
limits. Meeting these limits is predicated on a combination of conservative I
design criteria, projection of hydraulic and pollutant loading rates, and
pilot testing to demonstrate system strengths and weaknesses under real-world •
conditions. To date, pilot testing in Columbus has utilized a sequencing *
batch reactor (SBR), and most testing has been at the Southerly plant. In
reviewing the work done to date, additional information needs to be gathered
on the impacts of blending Jackson Pike and Southerly primary effluent to
determine if nitrification rates can be sustained. •
I
It will also be necessary to limit the mass loading of TKN to the •
Southerly waste treatment plant in order for the nitrification process to be
effective. Periodic high loadings of TKN have resulted in the bleedthrough of
ammonia from the primary effluent during the Project 20 pilot demonstration.
Unless these loads of TKN are controlled, all three biological processes would
be subject to ammonia bleedthrough resulting in violation of the permit •
ammonia concentration and mass-loading limits.
Meeting total suspended solids and BOD limits is primarily a function of
clarifier efficiency. Soluble BOD is rapidly removed in the aeration basin. •
That portion of the BOD associated with the particulates in the wastewater as •
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well as the suspended solids which escape from the clarifier, would cause BOD
or suspended solids violations. Controlling suspended solids violations is
based on controlling the SVI of both Jackson Pike and Southerly biological
treatment systems.
All three processes have the ability to select against filamentous
organisms which cause bulking. The semi-aerobic and activated sludge systems,
as demonstrated by Project 20 data, could reduce SVIs and keep ammonia
concentrations well within permit limits given the absence of slug primary
effluent ammonia loadings. Operating data for the Southerly waste treatment
plant from 1983 through 1986, indicate SVIs in the range of 75 to 181 are
possible. (Sentence deleted)
Denitrification is equally important during the summer months.
Denitrification will prevent the formation of a rising sludge in the final
clarifiers. No amount of clarifier upsizing or clarifier configuration
modification can prevent a violation during episodes of rising sludges. It
is, therefore, necessary that the denitrifiers complete the chemical reaction,
converting the nitrates into nitrogen and carbon dioxide, in the aeration
basin. This is accomplished by overpumping the secondary clarifiers,
maintaining a minimum sludge blanket in those clarifiers, and holding the
mixed liquor suspended solids in the aeration basin to 3500 mg/1 (Southerly
plant). Denitrification also has the side benefit of eliminating nitrites and
nitrates from the plant effluent.
At the present time there is no nitrate or nitrite standard in the Ohio
EPA permit limitations written for the Jackson Pike and Southerly plants.
However, removing these pollutants from the effluent wastewater would result
in the removal of pollutants from the receiving waters and subsequently any
groundwaters which are recharged from the surface waters. Denitrification is
considered a benefit, not only in terras of removing unwanted pollutants from
the surface waters and the groundwaters of the state, but also in terms of
limiting the occurrence of rising sludges in the secondary clarifiers.
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Another secondary benefit from the semi-aerobic process would be that it
is a biological phosphorus removal system. Although phosphorus removal
increases the volume of sludge to be treated by both Southerly and Jackson
Pike, it also results in the removal of a nutrient pollutant from the surface
water and groundwater.
A negative environmental impact of odor and pests in the form of flies is
associated with the trickling filter/activated sludge option. Trickling
filters have been cited in odor complaints particularly under conditions of
high organic loadings such as will be employed in the roughing filters
proposed for Jackson Pike and Southerly. In addition, fly larvae and flies
have been known to breed on these filter media resulting in nuisance
complaints. Attempts to control odors and flies by covering the trickling
filters results in the installation of a drafting system to allow adequate air
to pass through the filter media. This would add cost to the system and may
result in reduced efficiency during the summer months.
3.4 COSTS
The biological treatment train cost components (shown in Table 3-11)
include trickling filters, aeration basins, aeration system blowers, blower
housing, diffusers, (and internal recycle loops in the case of semi-aerobic
systems), and clarification processes. Table 3-11 provides a comparison
between the costs from the Revised Facility Plan Update and the briefing paper
costs.
In general, costs developed for this briefing paper are lower than those
presented in the facility plan due to lower projected average and peak flows.
In general, the higher facility plan costs at Southerly for the two-plant
alternative are due to the fact that a new east train was required. The lower
projected flows used in the briefing paper analysis did not require a new east
train for the two-plant option.
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C-43
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Under the combined plant option, the lower costs associated with the
briefing paper estimates are due to the requirement for fewer treatment
facilities based on lower flows.
In most cases, the serai-aerobic option was less costly than the trickling
filter/activated sludge option. This is due to the fact that a significant
portion of the required aeration capacity already exists.
The briefing paper analysis also reviewed the clarifier evaluation
prepared during the facility planning process. In this clarifier evaluation,
it was assumed that the Southerly One-Plant Alternative would be implemented.
Three clarifier configurations were developed. These included:
• Alternative 1: Construction of 12 new 200-foot diameter clarifiers,
• Alternative 2: Constructing 6 new 200-foot diameter clarifiers for the
east train, using all existing clarifiers for the center train, and
constructing three 200-foot diameter clarifiers for the west train.
• Alternative 3: Constructing 6 new 200-foot diameter clarifiers for
the east train; using existing rectangular clarifiers and adding 2 new
175-foot diameter clarifiers for the center train; and using the
existing rectangular clarifiers and adding 2 new 175-foot diameter
clarifiers to the west train.
Alternative 3 was discarded as being unworkable in terras of hydraulic
limitations. Alternatives 1 and 2 were evaluated with a cost of $43,194,000
for Alternative 1, and $40,126,000 for Alternative 2. The RFPU study
concluded that the two alternatives exhibit similar present worth costs.
Consequently, due to the advantages of circular clarifiers, it was recommended
that the existing clarifiers be demolished and new 200-foot clarifiers be
installed. These advantages include:
• Easier flow splitting and control of flow to each clarifier.
• Reduction in the number of telescoping sludge valves to be controlled.
• Ability to provide flocculation within the clarifier.
• Less potential risk for shortcircuiting.
• Automatic scum removal for the entire surface.
• Less complicated construction phasing.
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In addition to these advantages the capability to rapidly return sludge
to the aeration basin is a distinct advantage of circular clarifiers. Due to
the low nitrification rates at Southerly, the briefing paper evaluation
concurs with the advantages of circular clarifiers and recommends their
installation at Southerly.
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4. COMPARISON OF BRIEFING PAPER AND FACILITY PLAN CONCLUSIONS
4.1 PROCESS SELECTION
The briefing paper analysis concurs with the facility plan in its
selection of the semi-aerobic process as the preferred biological process.
The process is superior to the trickling filter/activated sludge process due
to its ability to provide nutrient removal and the flexibility of process
control it affords operators. As previously stated, the semi-aerobic system
is essentially the same as the conventional activated sludge system and could
easily be operated in the conventional activated sludge mode if necessary.
Although the trickling filter/activated sludge option is considered reliable,
it does exhibit the disadvantages of producing nuisance odors and pests, and
requires additional space to implement.
Process selection is also predicated on the assumption that Columbus will
implement and enforce a rigid industrial preteatment program which will limit
the concentration of toxic pollutants and slug loads of ammonia. Pilot data
have indicated that slug loads of ammonia or TKN will pass through the primary
clarifiers and may result in ammonia bleedthrough from the aeration basins.
These influent conditions must be controlled to ensure that any biological
process will perform effectively and meet permit limitations.
4.2 CLARIFIER UTILIZATION
The briefing paper evaluation agreed with the facility plan
recommendation to demolish the existing rectangular clarifiers at Southerly
and replace them with new circular clarifiers. Due to the lower flows and
loads utilized in the briefing paper analysis, less facilities are recommended
in the briefing paper for both the Southerly one-plant and Southerly two-plant
alternatives.
Contrary to the RFPU, the briefing paper recommends retaining the
existing retangular clarifiers at Jackson Pike. The arguments for the
selection of circular clarifiers at Southerly, primarily high mixed liquor
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suspended solids, the need for overpumping, and low nitrification rates do not
apply to the Jackson Pike waste treatment facility. The 12 existing
rectangular clarifiers at Jackson Pike should be rehabilitated, and 2 addi-
tional rectangular clarifiers should be constructed to provide adequate final
effluent clarification capacity.
4.3 ONE-PLANT VS. TWO-PLANT
The decision to utilize a combined one-plant option versus a two-plant
option must be based on process reliability as well as cost factors. The data
presented in this briefing paper shows the biological treatment process for
the two-plant option is less costly. The unknown factor at this point is the
effect of nitrification rates on blending Jackson Pike and Southerly primary
effluent. In the absence of this data, it is speculative to recommend a one-
plant versus two-plant option based on process considerations alone.
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APPENDIX D
BRIEFING PAPER NO. 4
O&M AND CAPITAL COSTS
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I BRIEFING PAPER NO. 4
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0 & M AND CAPITAL COSTS
Supplemental Environmental Impact Statement
IUSEPA Contract No. 68-04-5035, D.O. No. 40
Columbus Ohio Waste-water Treatment Facilities
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Prepared By:
• SCIENCE APPLICATIONS INTERNATIONAL CORPORATION
I TRIAD ENGINEERING INCORPORATED
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O&M AND CAPITAL COSTS
1. DEVELOPMENT OF BRIEFING PAPER COSTS
1.1 CAPITAL COSTS
1.2 O&M COSTS
2. FACILITY PLAN COSTS
3. COMPARISON OF BRIEFING PAPER AND FACILITY PLAN COSTS
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INTRODUCTION
Under the direction of USEPA, a series of briefing papers are being
prepared addressing key issues in the development of the Supplemental
Environmental Impact Statement for the Columbus, Ohio, Wastewater Treatment
Facilities. The briefing papers form the basis of discussions between Triad
Engineering and USEPA to resolve important issues. The following paragraphs
present the background of the facility planning process, a description of the
briefing papers, and the purpose of this paper on costs.
FACILITY PLANNING PROCESS
At the time this paper was prepared (March-July 1987) the city of
Columbus was proceeding to implement improvements at the Jackson Pike and
Southerly Wastewater Treatment Plants to comply with more stringent effluent
standards which must be met by July 1, 1988. These improvements were based
on the consolidation of wastewater treatment operations at the Southerly
plant. This one-plant alternative is a change from the two-plant operation
proposed by the city in the 1970's and evaluated in the 1979 EIS.
The development and documentation of wastewater treatment process and
sludge management alternatives for the Columbus metropolitan area has been an
extended and iterative process. The design and construction of various
system components have progressed, because of the 1988 deadline, while
planning issues continue to be resolved. As a result, numerous documents have
been prepared which occasionally revise a previously established course of
direction.
The concurrent resolution of planning issues and implementation of
various project components has made preparation of the EIS more difficult
because final facility plan recommendations are not available in a single
document.
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BRIEFING PAPERS
To facilitate preparation of the EIS, a series of briefing papers are
being developed. The purpose of the briefing papers is to allow USEPA to
review the work of the EIS consultant and to identify supplemental information
necessary for the preparation of the EIS. Six briefing papers are being
prepared as follows:
• Flows and Loads
• Sludge Management
• CSO
• Process Selection
• One Plant vs. Two Plant (Alternative Analysis)
• O&M and Capital Costs
The specific focus of each briefing paper will be different. However,
the general scope of the papers will adhere to the following format:
• Existing conditions will be documented.
• Evaluations, conclusions, and recommendations of the facilities
planning process will be reviewed using available documentation.
• Where appropriate, an independent evaluation of the future situation
and viable alternatives will be prepared.
• The facility plan and EIS briefing paper conclusions will be compared.
The briefing paper process is intended to:
• Prompt the resolution of any data deficiencies.
• Clearly establish and define existing and future conditions.
• Identify the final recommended plan which the city desires to implement.
• Provide a data base of sufficient detail to allow preparation of the
draft EIS.
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O&M AND CAPITAL COSTS
This briefing paper presents capital and operation and maintenance costs
associated with the Southerly One-Plant and Jackson Pike and Southerly Two-
Plant alternatives. Topics addressed include:
• Development of briefing paper capital and O&M costs
• Facility plan capital and O&M costs
• Comparison of briefing paper and facility plan costs
The briefing paper cost analysis is based on the 2008 design flows and
loads which were presented in the Wastewater Flows and Loads Briefing Paper.
The facility plan costs are taken from the 1985 Revised Facility Plan Update.
These costs were developed for a 30-year planning period ending in 2015.
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1. DEVELOPMENT OF BRIEFING PAPER COSTS
This section presents briefing paper capital and O&M costs for the
Southerly One-Plant, Southerly Two-Plant, and Jackson Pike Two-Plant
alternatives. Due to the differences in design flows between the facility
plan and the briefing papers, an independent cost analysis was prepared based
on the 2008 flows and loads developed in the Wastewater Flows and Loads
Briefing Paper. Table 1-1 presents the flows and loads which were used as a
basis for developing these costs. The Process Selection Briefing Paper
recommended the semi-aerobic process. Therefore, O&M and capital costs were
developed assuming semi-aerobic as the biological process being employed.
Solids handling costs are consistent with facilities recommended in the Solids
Handling Briefing Paper.
TABLE 1-1. BRIEFING PAPER FLOWS AND LOADS
Jackson Pike Southerly
Average Flow (MGD) 70 84
Peak Process Flow (MGD) 100 131
BOD Load (Ib/day) 112,600 155,600
TSS Load (Ib/day) 128,500 154,400
NOTE: Average flows in excess of 70 MGD and peak process flows in excess of
100 MGD at Jackson Pike will be diverted to Southerly under the two-
plant alternative.
1.1 CAPITAL COSTS
Detailed cost estimates prepared during the facilities planning process
by the Turner Construction Company were utilized in preparing the construction
costs for this briefing paper. These cost estimates were reviewed in detail
and adjusted as appropriate to account for differences in the briefing paper
design flows and unit process sizing. Table 1-2 presents the construction
costs for the Southerly One-Plant, Southerly Two-Plant, and Jackson Pike Two-
Plant alternatives.
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TABLE 1-2. BRIEFING PAPER CAPITAL COSTS
• Southerly Southerly Jackson Pike
Cost Component (One-Plant) (Two-Plant) (Two-Plant)
(Site Work $ 22,932,000 $ 11,448,000 $ 1,550,000
Miscellaneous Buildings 5,232,000 4,857,000 1,857,000
Plumbing/HVAC 5,875,000 5,875,000 4,337,000
IHeadworks 14,300,000 — 8,271,000
Preaeration 5,905,000 1,533,000 3,750,000
Primary Settling 13,590,000 4,717,000 7,372,000
m Aeration 46,533,000 12,284,000 22,502,000
• Final Settling 35,462,000 20,521,000 8,691,000
» Chlorination 4,000,000 2,500,000 2,000,000
Effluent Pumping 6,270,000 — 4,340,000
I Outfall Line 3,000,000 — 700,000
Gravity Thickening 5,070,000 2,520,000 1,967,000
Digestion 11,460,000 4,280,000 9,170,000
— Centrifuge Thickening 5,600,000 2,000,000 4,500,000
• Centrifuge Dewatering 21,040,000 5,120,000 490,000
* Dewatered Sludge Storage 1,300,000 1,300,000
Incineration 1,300,000 — 3,600,000
•Sludge Conveyor System — — 5,000,000
Instrumentation & Control 10,070,000 4,799,000 6,995,000
Electrical Distribution 1,896,000 1,896,000 607,000
I Jackson Pike Rehabilitation 13,564,000
Interconnector South 4,982,000
Interconnector North 5,048,000
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— 5,048,000
TOTAL CONSTRUCTION COSTS $244,429,000 $ 85,650,000 $102,747,000
Contingency (15%) 36,664,000 12,848,000 15,412,000
Land 200,000 200,000
Salvage Value (PW) - 12,582,000 - 4,644,000 - 5,137,000
CAPITAL PRESENT WORTH $268,711,000 $ 94,054,000 $113,022,000
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1.2 O&M COSTS
Operation and maintenance costs were developed for each plant alter-
native. The costs are presented in Table 1-3. The basis of these costs are
described in the following paragraphs.
TABLE 1-3. BRIEFING PAPER ANNUAL O&M COSTS ($)
Southerly Southerly Jackson Pike
(1-Plant) (2-Plant) (2-Plant)
Labor 4,050,000 2,850,000 2,880,000
Material & Supply 4,446,000 2,250,000 2,412,000
Chemicals 1,197,000 580,000 658,000
Energy 4,800,000 2,425,000 2,425,000
Land Application 712,000 342,000 712,000
Composting 1,314,000 1,314,000
Ash Disposal 330,000 60,000 170,000
TOTAL 16,849,000 9,821,000 9,257,000
NOTE: These costs are based on 2008 design flows and loads.
Labor costs for operation and maintenance were determined by evaluating
information on the number of employees currently employed at the treatment
facilities and their respective salaries. An average annual salary (including
benefits) of $30,000 per employee was established for future cost projections.
The projected number of workers for each alternative is 135 for the Southerly
One-Plant, 95 for the Southerly Two-Plant, and 96 for the Jackson Pike Two-
Plant.
Typically, annual material and supply costs are estimated as a percentage
of total construction costs. However, in this situation, with a portion of
the facilities already in place, doing so may underestimate the actual cost.
Therefore, cost curves were used to determine the construction costs for each
plant alternative as a new facility. One percent of this cost was estimated
as the annual material and supply cost.
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Chemical costs were determined for three processes: chlorination,
centrifuge thickening, and centrifuge dewatering. A current chlorine cost of
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$200 per ton and a polymer cost of $1 per pound were used for these estimates.
Costs for electrical energy were estimated based on costs documented in
the 1985 Operating Report prepared by the City of Columbus Division of
Sewerage and Drainage. These costs were adjusted to account for the
following:
• An increase in power costs from $0.04 to $0.05 per kilowatt-hour
• An increase in average flow from 145 MGD to 154 MGD
• Additional oxygen requirements for nitrification
Fuel cost estimates were determined based on the assumption that the
future solids handling scheme would include digestion and dewatering to a
minimum cake solids content of 22 percent. Under this assumption, enough
sewage gas is produced to meet the fuel requirements of the incinerators and
the digesters. Additional fuel cost estimates for heating and service were
based on costs documented in the 1985 Operating Report prepared by the City of
Columbus Division of Sewerage and Drainage. Fuel costs for heating and
service were estimated as $200,000 per year for each plant under the two-plant
alternative and $350,000 per year for the Southerly One-Plant Alternative.
The total energy cost for the Jackson Pike WWTP and the Southerly WWTP in 1985
was $4.5 million. In comparing this cost to the 2008 projected cost of $4.7
million, it must be remembered that the following factors differ between the
two costs.
• In 1985 the Southerly digesters were not operating.
• Dewatered cake solids at both plants averaged only 17 percent in 1985.
• Power costs in 1985 were $0.04 per kilowatt-hour.
• There is a 6 percent increase in average flow from 1985 to 2008.
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Land application is a contract operation. Based on past contract costs
from the city, it has a unit cost of $15 per wet ton.
Operation and maintenance costs for the compost facility were estimated
based on historical O&M costs. A unit cost of $30 per wet ton was used. This
cost includes materials, supplies, energy, and labor.
Ash disposal, which includes hauling and landfilling, was estimated at a
cost of $15 per cubic yard.
The total present worth O&M cost for the combined Jackson Pike and
Southerly Two-Plant option is $189,940,000. This cost is 13 percent higher
than the Southerly One-Plant cost of $168,200,000.
Table 1-4 presents the present worth of the O&M costs for each plant
alternative.
TABLE 1-4. BRIEFING PAPER O&M COSTS ($)
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1988-1992
1993-1997
1998-2002
2003-2007
Total
Southerly
[1-Plant]
16,047,000
16,247,500
16,448,000
16,648,500
Southerly
[2-Plant]
8,848,000
9,091,000
9,334,000
9,577,000
Jackson Pik
[2-Plant]
9,257,000
9,257,000
9,257,000
9,257,000
Present Worth
(1988)
168,200,000
94,140,000
95,800,000
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2. FACILITY PLAN COSTS
Costs were presented in the Revised Facility Plan Update (RFPU)
for the Southerly One-Plant, Southerly Two-Plant, and Jackson Pike Two-Plant
alternatives. These costs are for facilities which were sized based on the
flows and loads presented in Table 2-1.
TABLE 2-1. FACILITY PLAN FLOWS AND LOADS
Jackson Pike Southerly Whittier Street Total
Average Flow (MGD) 101 75 — 176
Peak Process Flow (MGD) 172 128 — 300
CSO (MGD) - - 130 130
BOD Load (Ib/day) 148,620 131,740 10,000 290,360
TSS Load (Ib/day) 170,390 126,550 20,000 316,940
NOTE: Flows at Jackson Pike in excess of 100 MGD will be diverted to
Southerly under the two-plant alternative. The additional flow of 130
MGD of CSO will be transported to Southerly under either alternative.
These flows and loads differ from those used in the briefing paper.
Table 2-2 presents the Revised Facility Plan Update capital costs associated
with these flows and Table 2-3 presents the RFPU O&M costs for the one-plant
and two-plant alternatives. The O&M costs associated with wet stream
treatment and solids handling were increased throughout the planning period to
account for increases in flows and loads. The O&M costs for headworks,
administration, Whittier Street facilities, and the Jackson Pike diversion
chamber were held constant throughout the planning period.
The RFPU O&M costs also include an amount allocated to "Other Capital
Costs". These costs were originally estimated with capital costs. The costs
are for rehabilitation or replacement of existing equipment. Table 2-4 shows a
breakdown of these costs.
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TABLE 2-2. FACILITY PLAN CAPITAL COSTS
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Cost Component
Site Work
Miscellaneous Buildings
Plumbing/HVAC
Headworks
Storm Bypass
Stormwater Tanks
Preaeration
Primary Settling
Aeration
Final Settling
Effluent Filters
Chlorination
Effluent Pumping
Outfall Line
Gravity Thickening
Digestion
Centrifuge Thickening
Thermal Conditioning
Centrifuge Dewatering
Incineration/Ash Lagoon
Lime Stabilization
Instrumentation & Control
Electrical Distribution
Jackson Pike Rehabilitation
Whittier Storm Tanks
Whittier to Jackson Pipe
Grit to Flow Diversion Pipe
Interconnector North
Interconnector South
Miscellaneous
TOTAL CONSTRUCTION COSTS
Engineering Fees
Land Acquistion
Process License Fees
Salvage Value
CAPITAL PRESENT WORTH
Southerly
(One-Plant)
$ 24,817,490
6,314,840
100,000
26,278,310
2,316,950
5,506,390
8,802,450
15,734,910
63,605,700
41,812,710
50,066,830
6,489,190
9,221,730
2,491,210
5,866,755
9,833,400
7,766,720
—
11,943,104
2,546,770
1,200,000
11,439,090
2,097,610
15,000,000
7,465,180
3,782,300
4,738,940
5,727,010
5,509,780
—
Southerly
(Two-Plant)
$ 21,120,060
5,856,230
100,000
19,536,520
2,316,950
5,506,390
6,516,490
13,020,930
34,661,730
33,848,295
29,682,210
4,367,810
122,340
—
4,781,660
5,913,650
5,120,895
—
6,721,880
2,546,770
1,200,000
8,697,710
2,097,610
—
7,465,180
3,782,300
4,738,940
6,279,510
5,509,780
—
Jackson Pike
(Two-Plant)
$ 8,056,750
3,514,900
3,071,870
10,163,620
—
—
4,148,080
5,819,100
23,856,500
9,832,890
25,060,510
3,218,280
7,321,300
796,280
7,272,140
9,377,250
6,917,630
3,030,260
517,580
3,975,830
—
8,331,650
607,160
—
—
—
—
—
—
5,000,000
$358,475,369
42,592,748
200,000
8,000,000
-5,431,000
$403,837,117
$241,511,840
26,629,941
200,000
4,000,000
-3,774.000
$268,567,781
$149,889,580
15,962,812
4,000,000
-2.059,000
$167,793,000
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TABLE 2-3. FACILITY PLAN O&M COSTS ($/YR)
WETS IDE
1988-1990
1991-1995
1996-2000
2001-2005
2006-2010
2011-2015
SOLIDS
1988-1989
1990-1999
2000-2015
WHITTIER STREET
2-PLANT
SOUTHERLY
4,642,259
5,694,560
6,078,667
6,466,235
7,030,124
7,694,711
6,109,400
6,380,500
6,511,500
2-PLANT
JACKSON PIKE
3,455,820
4,225,624
4,589,694
4,976,569
5,625,354
6,416,125
4,887,200
5,090,000
5,192,400
2-PLANT
TOTAL
8,098,079
9,920,184
10,668,361
11,442,804
12,655,478
14,110,836
10,996,600
11,470,500
11,703,900
1 -PLANT
SOUTHERLY
6,478,414
7,953,897
8,408,234
8,929,529
9,581,484
10,451,592
8,100,200
8,426,500
8,956,400
1995-2015
JP DIVERSION CHAMBER
1988-2015
HEADWORKS
1988-1089
1990-2015 687,400
ADMINISTRATIVE
1988-2015 400,000
OTHER CAPITAL
1986-2000 915,995
TOTAL
Present Worth
(1985)
127,734,009
47,900
136,000
1,074,660
1,074,660
400,000
366,066
104,785,539
47,900
136,000
1,074,660
1,762,060
800,000
1,282,061
232,519,548
47,900
136,000
1,219,500
500,000
1,141,329
176,166,114
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TABLE 2-4. FACILITY PLAN OTHER CAPITAL COSTS
COST ($)
SOUTHERLY (ONE-PLANT)
Preaeration
Replace Diffusers 193,000
Replace Flushing Equipment 26,000
Replace Blowers 88,000
Replace Cross Collectors 111,000
Pr raary Settling
Replace Flights, Chains, and Cross Collectors 1,800,000
Replace Skimming Equipment 90,000
Weir Replacement 100,000
Digester Renovation 3,600,000
Centrifuges - Automatic Backdrives 300,000
HVAC Renovation 8,747,500
Jackson Pike Sewer Maintenance Yard 975,440
Incineration 1,300,000
TOTAL 17,330,940
SOUTHERLY (TWO-PLANT)
Preaeration
• Replace Diffusers 193,000
• Replace Flushing Equipment 26,000
• Replace Blowers 88,000
• Replace Cross Collectors 111,000
Digester Renovation 3,600,000
HVAC Renovation 8,747,500
Jackson Pike Sewer Maintenance Yard 975,440
TOTAL 13,740,940
JACKSON PIKE (TWO-PLANT)
Miscellaneous Building Renovation 257,000
Primary Building Renovation 168,000
Primary Tanks
Not Filling Tanks 230,000
Replace Flights, Chains, and Cross-Collectors 991,000
Replace Skimming Equipment 133,000
Replace Weirs 214,000
Replace Sluice Gates 266,000
Ae ation
Replace Sluice Gates 932,000
Renovate Control Building 612,000
HVAC Renovation 1,918,000
TOTAL 5,721,000
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3. COMPARISON OF BRIEFING PAPER AND FACILITY PLAN COSTS
Tables 3-1 and 3-2 present cost comparisons between the one- and two-plant
alternatives for the briefing paper and facility plan, respectively. The
facility plan shows the two-plant alternative being 15 percent more costly than
the one-plant. However, the briefing paper shows the one-plant as 10 percent
more costly than the two-plant. This difference between the facility plan and
the briefing paper is primarily a result of differences in design flows. At
the briefing paper's lower flows, a new east train, headworks, and expanded
Interconnector Sewer are not required under a two-plant alternative. At the
facility plan flows, these facilities are required under either alternative.
However, they vary in size being larger for the one-plant.
A direct cost comparison between the briefing paper and facility plan
costs is not possible for several reasons. There is a difference in design
flows, costing methods, equipment (the facility plan's recommended CSO
facilities), and planning periods.
The difference in flows between the facility plan is 22 MGD for average
flow and 69 MGD for peak flow. This difference affects the costs for the
two-plant alternative more than the one-plant alternative.
The method used in the facility plan for O&M costs also caused
differences in the capital costs between the briefing paper and the facility
plan. As discussed in Section 2, the facility plan shifted some
rehabilitation costs from capital to O&M. The following processes were
affected by this shift:
• HVAC renovation
• Preaeration
• Primary Settling
• Aeration
• Centrifuge Dewatering
• Incineration
• Digestion
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TABLE 3-1. PRESENT WORTH OF BRIEFING PAPER CAPITAL AND O&M COSTS
Capital O&M Total
One-Plant [Southerly] 268,711,000 168,200,000 436,911,000
Two-Plant [So. and JP] 207,076,000 189,940,000 397,016,000
Difference From One-Plant -61,635,000 +21,740,000 -39,895,000
Percent Difference -30 +13 -10
NOTE: These costs are based on a 2008 average flow of 154 MGD and a peak flow
of 231 MGD. Present worth costs are in 1988 dollars.
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TABLE 3-2. PRESENT WORTH OF FACILITY PLAN CAPITAL AND O&M COSTS
Capital O&M Total
One-Plant [Southerly] 403,837,000 176,166,000 580,003,000
Two-Plant [So. and JP] 436,361,000 232,519,000 668,880,000
Difference From One-Plant +32,524,000 +56,353,000 +88,877,000
Percent Difference +8 +32 +15
NOTE: These costs are based on a 2015 average flow of 176 MGD and a peak flow
of 300 MGD. Costs are included for an additional 130 MGD of CSO
facilities. Present worth costs are in 1985 dollars.
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A. portion of the costs were for routine maintenance costs such as
painting and roof repairs. These costs are covered under annual maintenance
expenditures. However, some of the costs were for major equipment renovation.
For example, the $6 million renovation of the existing digesters, which have
not operated since 1980, was placed under the O&M costs as "Other Capital
Costs". It was felt that these costs should remain in the capital costs. The
city has indicated that the digesters are currently undergoing renovation.
Therefore, the briefing paper capital costs include these costs. The cost of
renovating the HVAC and plumbing systems was placed under O&M costs in the
facility plan because the systems will be replaced as they become inoperable.
The briefing paper included this cost as capital expenditures in the future
brought back to a present worth amount.
An additional factor in the cost difference between the briefing paper
and the facility plan costs is the recommended CSO facilities. Triad has not
included costs for facilities to control CSO as the city has. Triad recom-
mends that a CSO study be completed prior to any recommmendations on CSO
facilities. The following facilities are included in the facility plan costs
for CSO:
• Storm bypass
• Stormwater tanks at Southerly
• Whittier storm tanks
• OSIS Relief Sewer from Whitter Street to the flow diversion chamber.
The costs for the CSO facilities are common to both a one and two-plant
alternative. Therefore, they do not have a significant impact on the
comparison between the costs of one-plant vs. two-plants.
Effluent filters are no longer needed at either plant due to changes in
the permit limits. Therefore, they were not included in the briefing paper
costs.
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The final factor-which causes a difference between the briefing paper and
facility plan costs is the planning period. The faciltiy plan has a 30-year
planning period beginning in 1985 and ending in 2015. The briefing paper
planning period extends 20 years, from 1988 to 2008. This affects the flow
projections, which in turn affect the capital costs. But more importantly, it
affects O&M costs. The facility plan has 30 years of annual O&M costs. These
costs are presented in 1985 dollars. The briefing paper only has 20 years of
O&M costs presented in 1988 dollars.
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APPENDIX E
BRIEFING PAPER NO. 5
COMBINED SEWER OVERFLOWS
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BRIEFING PAPER NO. 5
COMBINED SEWER OVERFLOWS
Supplemental Environineiital Impact Statement
USEPA Contract No. 68-04-5035, D.O. No. 40
Columbus Ohio Wastewater Treatment Facilities
Prepared By:
SCIENCE APPLICATIONS INTERNATIONAL CORPORATION
TRIAD ENGINEERING INCORPORATED
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COMBINED SEWER OVERFLOW
1. TERMS AND CONDITIONS
2. AVAILABLE DATA
3. CSO ANALYSIS
3.1 Traditional Approach
3.2 RFPU Approach: Review and Critique
3.3 Briefing Paper Analysis
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INTRODUCTION
Under the direction of USEPA, a series of briefing papers are being
prepared addressing key issues in the development of the Supplemental
Environmental Impact Statement for the Columbus, Ohio, Wastewater Treatment
Facilities. The briefing papers form the basis of discussions between Triad
Engineering and USEPA to resolve important issues. The following paragraphs
present the background of the facility planning process, a description of the
briefing papers, and the purpose of this paper on Combined Sewer Overflow
(CSO).
FACILITY PLANNING PROCESS
At the time this paper was prepared (June-August 1987) the city of
Columbus was proceeding to implement improvements at the Jackson Pike and
Southerly Wastewater Treatment Plants to comply with more stringent effluent
standards which must be met by July 1, 1988. These improvements were based on
the consolidation of wastewater treatment operations at the Southerly plant.
This one-plant alternative is a change from the two-plant operation proposed
by the city in the 1970's and evaluated in the 1979 EIS.
The development and documentation of wastewater treatment process and
sludge management alternatives for the Columbus metropolitan area has been an
extended and iterative process. The design and construction of various system
components have progressed, because of the 1988 deadline, while planning
issues continue to be resolved. As a result, numerous documents have been
prepared which occasionally revise a previously established course of
direction.
The concurrent resolution of planning issues and implementation of
various project components has made preparation of the EIS more difficult
because final facility plan recommendations are not available in a single
document.
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BRIEFING PAPERS
To facilitate preparation of the EIS, a series of briefing papers are
being developed. The purpose of the briefing papers is to allow USEPA to
review the work of the EIS consultant and to identify supplemental information
necessary for the preparation of the EIS. Six briefing papers are being
prepared as follows:
• Flows and Loads
• Sludge Management
• Process Selection
• O&M and Capital Costs
• CSO (Combined Sewer Overflows)
• One Plant vs. Two Plant (Alternative Analysis)
The specific focus of each briefing paper will be different. However,
the general scope of the papers will adhere to the following format:
• Existing conditions will be documented.
• Evaluations, conclusions, and recommendations of the facilities
planning process will be reviewed using available documentation.
• Where appropriate, an independent evaluation of the future situation
and viable alternatives will be prepared.
• The facility plan and EIS briefing paper conclusions will be compared.
The briefing paper process is intended to:
• Prompt the resolution of any data deficiencies.
• Clearly establish and define existing and future conditions.
• Identify the final recommended plan which the city desires to
implement.
• Provide a data base of sufficient detail to allow preparation of the
draft EIS.
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COMBINED SEWER OVERFLOWS
This briefing paper presents an independent evaluation of the status of
the Combined Sewer Overflow (CSO) problem in the city of Columbus. The
Supplemental Environmental Impact Statement being prepared will address only
Phases 1 and 2 of the city's facility planning process. The city has advised
USEPA that these two phases do not contain provisions for CSO. Normal
facility planning processes incorporate CSO into the plan prior to developing
design flows for wastewater treatment facilities. However, the city of
Columbus intends to conduct a detailed CSO analysis after a majority of the
wastewater treatment facilities are in place.
The purpose of this briefing paper is to describe the traditional
approach to the problem of CSO analysis and in this light, review and critique
the approach used in the 1985 Revised Facility Plan Update (RFPU). While the
lack of data does not allow a comprehensive analysis of the CSO problem, some
general calculations are provided in comparison to those in the RFPU.
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1. TERMS AND DEFINITIONS
The following terras and definitions are contained in Appendix A of the
current USEPA Region V NPDES Permit Strategy for Combined Sewer Systems. This
list is reprinted in its entirety and thus, not all of the terras are referred
to in this briefing paper. These terms are used throughout the discussions in
this briefing paper.
Best Management Practices (BMPS); - means schedules of activities,
prohibitions of practices, maintenance procedures, and other management
practices to prevent or reduce the pollution of "waters of the United States."
BMPS also includes treatment requirements, operating procedures, and practices
to control plant site runoff, spillage or leaks, sludge or waste disposal, or
drainage from raw material storage. (40 CFR 122.2).
Bypass: - the intentional diversion of waste streams from any portion of a
treatment facility. (40 CFR 122.41(m)(4)). "Treatment Facility" means
"Treatment Works" as defined below.
Combined Sewer: - a sewer that is designed as a sanitary sewer and a storm
sewer. (40 CFR 35.2005(b)(ll)). (This is distinguished from a sanitary sewer
to which inflow sources prohibited by the sewer use ordinance have been
connected).
Complete Waste Treatment System; - a complete waste treatment system consists
of all the treatment works necessary to meet the requirements of title III of
the Act, involving: (i) the transport of wastewater from individual homes or
buildings to a plant or facility where treatment of the wastewater is
accomplished; (ii) the treatment of the wastewater to remove pollutants; and
(iii) the ultimate diposal, including recycling or reuse, of the treated
wastewater and residues which result from the treatment process (40 CFR
35.2005(b)(12)). (the catch basins and overflow points are part of the
complete waste treatment system in a combined sewer system. Also see No. 17,
below.)
Dry Weather Flow; - flows that are not attributable to rainfall or snowmelt,
and include infiltration.
Excessive Infiltration: - the quantity of infiltration which can be
economically eliminated from a sewer system as determined in a cost-
effectiveness analysis that compares the costs for correction of the
infiltration conditions to the total costs for transportation and treatment of
the infiltration. (40 CFR 35.2005(b)(16)).
Excessive Inflow; - the quantity of inflow which can be economically
eliminated from a sewer system as determined by a cost effectiveness analysis
that compares the costs for correcting the inflow conditions to the total
costs for transportation and treatment of the inflow (normally determined in
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conjunction with the determination of excessive infiltration). (40 CFR
35.2005(b)(16)).
Infiltration; - water other than wastewater that enters a sewer system
(including sewer service connections and foundation drains) from the ground
through such means as defective pipes, pipe joints, connections, or manholes.
Infiltration does not include, and is distinguished from, inflow. (40 CFR
35.2005(b)(20)).
Inflow; - water other than wastewater that enters a sewer system (including
sewer service connections) from sources such as, but not limited to, roof
leaders, cellar drains, yard drains, area drains, drains from springs and
swampy areas, manhole covers, cross connections between storm sewers and
sanitary sewers, catch basins, cooling towers, storm waters, • surface runoff,
street wash waters, or drainage. Inflow does not include, and is
distinguished from, infiltration (40 CFR 35.2005(b)(21)).
Nonexcessive Infiltration; - The quantity of flow which is less than 120
gallons per capita per day (domestic base flow and infiltration) or the
quantity of infiltration which cannot be economically and effectively
eliminated from a sewer system as determined in a cost effectiveness analysis.
(40 CFR 35.2005(b)(28)).
Nonexcessive Inflow; - The maximum total flow rate during storm events which
does not result in chronic operational problems related to hydraulic
overloading of the treatment works or which does not result in a total flow of
more than 275 gallons per capita per day (domestic base flow plus infiltration
plus inflow). Chronic operational problems may include surcharging, backups,
bypasses, and overflows. (40 CFR 35.2005(b)(29)).
Operational Plan; - The objective of the operational plan is to reduce the
total loading of pollutants entering the receiving stream from the complete
waste treatment system. This plan, tailored to the local government's
complete waste treatment system, will include mechanisms and specific
procedures to ensure:
a. the collection and treatment systems are operated to maximize
treatment;
b. all dry weather flows are treated to the level specified in their
permit;
c. storm water entry into the sewerage system is regulated;
d. the sewerage system hydraulic and storage capacity is identified and
fully utilized during wet weather with eventual treatment of stored
flows;
e. the greatest quantity of wet weather flows receive maximum possible
treatment;
f. the sewerage system is adequately maintained to ensure optimum
operational capability.
Overflow; - the uncontrolled diversion of waste streams from a combined sewer
system which occurs during wet weather when flows exceed conveyance capacity.
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Sanitary Sewer; - a conduit: intended Co carry liquid and water-carried wastes
from residences, commercial buildings, industrial plants, and institutions
together with minor quantities of ground, storm, and surface waters that are
not admitted intentionally. (40 CFR 35.2005(b)(37)).
Sewer Use Ordinance: - that ordinance or other legally binding document
enacted to prohibit any new connections from inflow sources into the sewer
system and require that new sanitary sewers and connections thereto are
properly designed and constructed. Such ordinance shall further require that
all wastewater introduced into the sewer system does not contain toxics or
other pollutants in amount or concentration that endanger public safety and
physical integrity of the sewer system, pump stations, or wastewater treatment
facilities, cause violation of effluent limitations or water quality
standards, or preclude the selection of the most cost-effective alternate for
wastewater treatment and sludge disposal. (40 CFR 35.2130).
Storm Sewer: — A sewer designed to carry only storm waters, surface run-off,
street wash waters, and drainage. (40 CFR 35.2005(b)(47)).
Treatment Works; - Any devices and systems for the storage, treatment,
recycling, and reclamation of municipal sewage, domestic sewage, or liquid
industrial wastes used to implement section 201 of the Act, or necessary to
recycle or reuse water at the most economical cost over the design life of the
works. These include intercepting sewers, outfall sewers, sewage collection
systems, individual systems, pumping, power, and other equipment and
alterations thereof; elements essential to provide a reliable recycled supply
such as standby treatment and clear water facilities; and any works, including
acquisition of the land that will be an integral part of the treatment process
or is used for ultimate disposal of residues resulting from such treatment
(including land for composting sludge, temporary storage of such compost, and
land used for the storage of treated wastewater in land treatment systems
before land application); or any other methods or system for preventing,
abating, reducing, storing, treating, separating, or disposing of municipal
waste or industrial waste, including waste in combined storm water and
sanitary sewer systems. (40 CFR 35.2005(b)(48)).
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2. AVAILABLE DATA
The operating records for both the Jaekson Pike and Southerly Wastewater
Treatment Plants include information regarding the major overflows for each
sewerage system, specifically, the Whittier Street Storm Tanks for the Jackson
Pike sewerage system and the bypass at the plant for the Southerly sewage
system. Additional reports which were reviewed for this analysis include the
fol lowing:
• Revised Facilities Plan Update (RFPU) prepared by URS Dalton September
30, 1985.
• General Engineering Report and Basis of Design (GERBOD) prepared by
URS Dalton January 31, 1986.
• Combined Sewer Overflow Monitoring Report prepared by Malcolm Pirnie,
Inc. January 2, 1979.
• CSO Progress Report prepared by Malcolm Pirnie, Inc. July 28, 1983.
• Central Scioto River Mainstem Comprehensive Water Quality Report
prepared by Ohio EPA September 30, 1986.
• Use of Combined Sewer Overflow Analysis in the September 30, 1985,
Revised Facilities Plan Update prepared by the city of Columbus March
23, 1987.
While the RFPU contains one page of conclusions reached in the CSO
analysis, there is no information provided describing the analysis itself.
The GERBOD provides greater detail on the analysis performed, which references
data provided in the CSO Montioring Report and the CSO Progress Report. The
final report cited was issued in response to questions by USEPA - Region V in
regard to the CSO analysis referenced in the RFPU.
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3. CSO ANALYSIS
3.1 TRADITIONAL APPROACH
The traditional approach to a combined sewer system analysis used in this
briefing paper is outlined in a recent USEPA - Region V document entitled
"Technical Guidance for Use in the Development of a Combined Sewer System
Operational Plan" published in September 1986. The recommended tasks in the
development of a stormwater management program are:
• Establishment of objectives
• Development of a data base
• Understanding the operation and response of the combined sewer system
• Identification of drainage areas
• Hydraulic analysis
• Review of meteorological data
• Monitoring of flows and collection of samples
• Selection of mathematical models
• Discussion of CSO control alternatives
The following paragraphs discuss these aspects in greater detail.
The establishment of objectives is a project specific task which leads
directly into the development of a data base.
The development of a data base allows a municipality to become
knowledgeable about its combined sewer system, including operation,
maintenance, and response to different meteorological conditions. Data is
obtained through detailed interviews with sewer, public works, and engineering
personnel. The data required for such a data base includes, but is not
limited to: geographical, geological, topographical, and hydrologic data;
known physical condition of the sewer system, manholes, and all appurtenances;
age, length, materials, sizes, slopes, and depths of sewers; maintenance
practices; problems and system failures; treatment plant flow records and
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charts; pumping station flow records, location of overflows and associated
operating experience and records; identification of sewer system problem
areas; available combined sewer system maps; groundwater levels for all
seasons, with correlation to rainfall; quality of local receiving waters and
required effluent or water quality standards; and existing ordinances
governing inflow connections to sewers and enforcement programs and policies,
as well as estimates of the extent and significance of such inflow
connections.
Detailed maps of the municipalities sewerage system should be up to date
and the combined, sanitary and storm sewer systems should be clearly defined.
The maps should show sewer sizes, slopes, direction of flow, manhole
locations, and other major sewer system elements such as regulating or control
structures and overflows. This information will allow a general understanding
of the operation and response of the sewerage system. These maps and data
will also allow the identification of drainage areas within the sewerage
system and thus establish key hydraulic locations where flows can be monitored
and gaged.
The hydraulic analysis proceeds from the collection of data in regard to
the sewerage system itself. This analyis allows the determination of the
hydraulic capacities of the sewers. The portion of the sewer system capacity
available for carrying stormwater runoff is a function of the total hydraulic
capacity of the sewerage system as determined by: the pipe size, slope and
material of construction, the quantitiy of flows; and the level to which a
particular sewer can surcharge without causing an overflow, basement flooding,
or other damage. The most important parameter which may be determined in the
hydraulic analysis is that of the time of concentration, which is used in the
computation of the peak stormwater runoff rate. Since most rainfall events
are of short duration, the peak rate of runoff is of primary importance, with
the total volume secondary.
The monitoring of flows and collection of samples should proceed only
after the hydraulic analysis and data collection efforts previously described
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have been completed. At key locations in the sewerage system and at the major
overflow points, as previously determined, flows should be monitored along
with collection of rainfall data. Further, it is desirable that samples be
collected at the overflows at short time intervals during an overflow in order
to associate pollutant concentrations with the overflow. The rain gauges
should be located throughout the sewer system service area in order to
characterize the rainfall in terms of duration, intensity, and volume. Thus,
in the knowledge provided by the data base and hydraulic analysis that all
flows are accounted for, the volume of overflow and mass loading of pollutants
discharged to the receiving waters may be computed. Then the intensity
duration relationships of the observed rainfalls may be compared to historical
records to relate the observed overflows to a recurrence interval. Thus,
statistical relationships may be developed which will relate rainfall to
overflow volumes and quality.
The CSO analysis may then be taken a step further in complexity with the
use of a mathematical model. Mathematical stormwater models are capable of
predicting the volume of stormwater discharge and its constituent pollutants.
These models typically consist of two elements - a runoff element that
simulates the washoff of pollutants by rainfall on the watershed, and a
transport element that simulates the movement of those pollutants in the sewer
system and their eventual discharge from it. Data from flow monitoring and
sampling efforts may be used to calibrate such a model after which the model
is an invaluable tool in evaluating the effectiveness of various control
alternatives and to identify optimum solutions.
3.2 FACILITIES PLAN APPROACH: REVIEW AND CRITIQUE
Very little of the data necessary for a traditional CSO analysis was
presented in the RFPU. Existing monitoring data was utilized from two support
documents: The Combined Sewer Overflow Report of January 1979, and the CSO
Progress Report of 1983.
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While Che quality of the monitoring data used is unknown, its value is
of some question due to the poorly developed data base regarding the sewerage
system. No maps of the sewerage system were presented or developed, thus, the
drainage areas for each overflow or each system (combined, sanitary, or storm)
were not clearly defined. While the CSO Progress Report (1983) did include a
discussion of computer modeling of the sewerage system with reference to the
Whittier Street Storm Tanks using the SWMM model, the input data was not
presented and the results were not discussed or presented. The Combined
Sewer Overflow Report (1979) includes a one year record of overflow monitoring
data for nineteen overflow sites, but the completeness of this record is
subject to some question. Further, due to the lack of data in regard to how
the sewerage system responds to wet weather conditions, whether or not all
major overflows are accounted for with the monitoring data is unknown. The
fact that both support documents and the RFPU overlooked the Renick Run
overflow supports this contention.
The discussion of the Combined Sewer Overflow analysis in the RFPU makes
four points:
1. The CSO analysis consisted of ten rainfall (overflow) events from 1979
and 1982.
2. The statistical analysis performed on these ten events showed that the
80th percentile storm could be controlled at a cost of $42 million.
3. The environmental impacts of the existing combined sewer overflows
were shown to be insignificant according to documentation in the Draft
OEPA Central Scioto River Water Quality Report and the city river
sampling results as reported in the monthly operating reports (MORs).
4. The city would meet its NPDES permit requirements regarding the sewer
system overflows and would continue to closely observe the Scioto
River, the Olentangy River, and Alum Creek in order to mitigate any
adverse environmental impacts due to overflows.
There is no other detail provided on the CSO analysis in the RFPU other
than to make these four points. It was not until four months later that the
analytical methodology for the CSO analysis was presented in the GERBOD
(January 31, 1986) and later in the report titled "Use of Combined Sewer
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Overflow Analysis" in the September 30, 1985, Revised Facilities Plan Update
(RFPU) which was submitted to USEPA - Region V March 23, 1987, by the city.
While it was stated in the RFPU that the environmental impacts of the
existing combined sewer overflows were shown to be insignificant according to
documentation in the draft OEPA Central Scioto River Water Quality Report
(CWQR), a review of this report did not substantiate this statement. In fact,
information in the CWQR suggests that the environmental impacts of the
existing CSOs are significant. On page 195 the CWQR states that "combined
sewer overflows, and as previously discussed, plant bypasses also contributed
significant loadings of BODc, NH-j-N, TSS, and other substances to the Central
Scioto River Mainstem". Further, page 317 states, "Reductions in the
magnitude and frequency of combined sewer overflow discharges is needed to
improve aquatic community function, alleviate aesthetic problems, and reduce
risks to human body contact recreation in the segment between Greenlawn Dam
and the Jackson Pike WWTP".
The combined sewer overflow analysis presented in the RFPU considered
only Whittier Street overflows and neglected all others including the bypass
flows at Southerly. The city analyzed ten events which were selected from a
larger data set of twenty-six events. The ten events selected were those that
had both quality and quantity data. Data for the events not selected was not
presented. Thus, due to the manner in which the ten events were selected,
whether or not they can be considered representative of flows at the Whittier
Street facility is questionable, and whether or not they can be considered to
be representative of combined sewer overflows from the entire sewerage system
is more questionable.
The statistical analysis performed for the RFPU consisted of plotting the
ten events on probability paper using a simple Weibull plotting position
calculation. Using this method, m is the rank of the event [highest (1) to
lowest (10)] and n is the number of events (10). The plotting position thus
calculated refers to the probability or return period that is associated with
each of the observed events. The use of this method is illustrated in Table
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1, where Che calculated plotting positions and associated return period for
each of the ten events analyzed are shown. Thus, for event number 1 of
10/8/77, a plotting position of 0.364 is calculated. This number refers to
the fact that 36.4 percent of the observed overflow volumes are less than that
of event number 1, while 63.6 percent of the observed overflow volumes are
greater that that of event number 1. Thus, if the data set is established and
representative, projections may be made on the overflow volumes. This method
further defines the recurrence interval (in years) as the inverse of the
calculated plotting position. Thus, the recurrence interval for event number
1 with a volume of 44.1 would be 1/0.364 or 2.75 years. Thus an overflow of
this magnitude could be expected to occur every 2.75 years. Note, however,
that the data base from which this projection is made consists of ten hand
picked events from a period of time of about one year. While the objective of
this method is to make such projections with a limited amount of data, the
questions still remain as to how representative these ten events are and what
about the other overflows in the system? The calculated probabilities of the
ten events may have easily been checked using the rainfall data for each event
and associating a recurrence interval with the rainfall intensity which
induced the overflows based on a histrocial record of rainfall for the area.
However, this check was not performed.
Thus, the 80th percentile overflow was shown to be 50 million gallons.
In addition, the 80th percentile overflow at Renick Run was estimated at 12 MG
by taking a simple proportion of the 80th percentile flow to the hydraulic
capacity of the pipes converging at each overflow. Thus, a total volume of 62
million gallons was recommended in the RFPU for storage or treatment and the
cost associated with control at this level was estimated at $42 million.
3.3 BRIEFING PAPER ANALYSIS
Lack of flow data does not allow an independent comprehensive
analysis of the CSO problem. Therefore, the following analysis is presented
only to provide data for comparison with the figures in the RFPU. The
combined sewer overflow volumes may be estimated using a procedure outlined in
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TABLE 1
Plotting Position (P)
Total CSO
Rank (ra)
Event Date Volume (MG) Highest to lowest
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
10/8/77
10/26/77
8/6/78
8/19/78
8/29/78
8/30/78
9/16/78
8/4/82
8/25/82
9/14/82
44.1
3.1
26.1
10.4
6.1
73.3
16.2
44.9
51.9
12.8
4
10
5
8
9
1
6
3
2
7
m/(n+l)
n=10
0.364
0.909
0.455
0.727
0.818
0.091
0.545
0.273
0.182
0.636
Recurrence
Interval (yr)
(1/P)
,75
.10
.20
.38
,22
10.99
,83
,66
.49
1.57
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reference 1. This method first estimates the percent imperviousness of the
area by the following equation:
Percent Imperviousness -1-9.6 PD<°-573 ~ °'0391 Io8 PD)
Where PD = Population Density (Persons Per Acre)
The population density for the combined sewer area for the city of
Columbus was cited as 15.78 persons per acre in reference 2. While the
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combined sewer service area is known to have decreased from 18.4 mi to the
*y
present estimate of 11.1 mi (as per city officials), the population density
for this area may be assumed to have remained about the same. Therefore, 16
persons per acre will be assumed, thus:
I = 9.6 (16)(0-573 ~ 0-0391 log 16)
= 41.3%
Next the runoff coefficient (CR) weighted between pervious and impervious
areas is estimated as follows:
CR - 0.15 + 0.75 (1/100)
- 0.15 + 0.75 (41.3/100) - 0.460
The area weighted depression storage (DS) is then estimated assuming
0.0625 inches for impervious areas and 0.25 inch for pervious areas.
DS - 0.25 - 0.1875 (1/100)
= 0.25 - 0.1875 (41.3/100) = 0.327 in.
Finally, the annual runoff (AR) is estimated for the CSO area in terms of
inches per year over the given area.
AR = (CR) P-5.234 (DS)0-5957
Where P » Annual precipitation, in/yr = 37.01 in/yr
AR - (0.46X37.01 in. )-(5. 234X0. 327 in.0'5951)
- 14.33 inches per year
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7
Since the existing combined sewer service area is known to be 11.1 mi ,
the estimated annual volume of runoff from this area may be calculated as
follows:
11.1 mi2 x 14.33 in. x 1 ft. x 52802 ft.2 x 7.481 Gal = 2,760 x 106 gallons per year
12 in. 1 mT21 ft.
A summary of the 1985 and 1986 precipitation record for the city of
Columbus is provided in Table 2. This table shows the number of days in which
precipitation was recorded for each year broken down by depth. In order to
relate the previously calculated annual volume of runoff from the combined
sewer area to a rainfall day basis, an average value for 1985 and 1986 of 58
significant days of rainfall may be assumed. A "significant" rainfall may be
defined as all days when greater than 0.15 inches of rainfall were recorded.
This number is reasonable since the depression storage for the combined sewer
area was previously calculated at 0,327 inches. Thus on a per-significant-
rainfall-day basis, a daily volume of runoff from the combined sewer area may
be calculated as follows:
2,760 x 106 Gallons _•_ 58 Significant Rainfall Days
Year * Year
= 48 x 106 Gallons
Signficant Rainfall Day
In addition to this flow, however, is inflow from the separate sewer area
which must be estimated. Since the extent of the inflow problem in the
separate sewer area is unknown, it will be assumed to be at the point of being
nonexcessive (refer to Section 1: Terms and Definitions). The construction
grants program defines a nonexcessive inflow value of 275 gallons per capita
per day (gpcd) as the maximum allowable total daily flow during a storm.
Thus, knowing that the average dry weather flow is 167 gpcd (ref. Briefing
Paper No. 1), a maximum allowable inflow volume of 108 gpcd can be assumed for
this area. The population for the separate sewer area may be estimated by
subtracting the product of the assumed combined sewer population density (16
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persons/acre) by the combined sewer area (11.1 mi = 7104 acres) from the
total service area population (870,000 persons). Thus the population served
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TABLE 2. PRECIPITATION
1985
Total
(Inches)
P
R
E
C
I
P
I
T
A
T
I
0
N
D
E
P
T
H
R
A
N
G
E
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
.00
.05
.10
.15
.20
.25
.30
.35
.40
.45
.50
.55
.60
.65
.70
.75
.80
.85
.90
.95
.00
.05
.10
.15
.20
.25
.30
.35
.40
.45
.50
.55
.60.
.65
to
to
to
to
to
to
to
to
to
to
to
to
to
to
to
to
to
to
to
to
to
to
to
to
to
to
to
to
to
to
to
to
to
to
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
.05
.10
.15
.20
.25
.30
.35
.40
.45
.50
.55
.60
.65
.70
.75
.80
.85
.90
.95
.00
.05
.10
.15
.20
.25
.30
.35
.40
.45
.50
.55
.60
.65
.70
Days
43
27
18
8
7
5
4
3
7
1
2
2
0
5
2
2
0
0
4
0
0
1
0
0
0
0
0
0
1
0
0
0
0
0
Depth
(In.)
0
1
2
1
1
1
1
1
2
0
1
1
3
1
1
3
1
1
.95
.82
.21
.33
.48
.34
.28 .
.13
.93
.47
.02
.13
.33
.42
.53
.69
.07
.41
1986
Total
Days
40
19
10
9
9
6
7
3
2
2
3
0
1
1
4
3
1
0
3
2
0
0
0
0
1
1
1
0
1
0
0
0
0
1
Depth
(In.)
0
1
1
1
1
1
2
1
0
0
1
0
0
2
2
0
2
1
1
1
1
1
.83
.24
.17
.48
.93
.65
.24
.1
.86
.95
.55
.63
.7
.89
.32
.82
.75
.93
.21
.29
.31
.69
ALL 143 31.92 130 35.04
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by the separate sewer area is about 756,336 persons. Therefore, the allowable
inflow from the separate sewer area may be estimated as:
108 gpcd x 756,336 persons = 82 x 106 Gallons
Day
The 108 gpcd figure used above as the inflow from the separate sewer area
may be put into perspective in the following manner. The daily volume
calculated above may be expected to occur on "significant" rainfall days, as
previously defined. The total "significant" rainfall average for 1985 and
1986 is shown to be 29.37 inches. Dividing this figure by the 58 significant
rainfall days per year (used previously) results in an average of 0.51 inches
of rainfall per significant rainfall day. This rainfall depth of 0.51 inches
over the entire separate sewer area equates to a volume of 1,320 x 10
gallons. Thus, the calculated inflow from the separate sewer area using the
275 gpcd maximum allowable daily total flow accounts for about 6.2 percent of
the total rainfall as inflow.
Therefore, the total combined sewer and inflow volume which must be dealt
with for each signficant rainfall day is estimated as follows:
Combined sewer area runoff and inflow 47.7 MG
Separate sewer area inflow 81.7 MG
Total 129.4 MG
Several points should be made in regard to this figure. While the method
used for the calculation of the annual runoff volume from the combined sewer
area is a general one, it certainly is what would be considered a "first order
approximation" using an EPA approved procedure. Secondly, since the extent of
the inflow problem in the separate sewer area has not been investigated or
defined, the estimate used must be assumed to be reasonable. It is important
to note that this brief analysis shows that the inflow problem from the
separate sewer service area on a volume basis could be greater than the runoff
and inflow from the combined sewer area. Further, note that for the inflow
from the separate sewer service area to be equal in volume to the runoff and
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inflow from Che combined sewer service area Chat only 3.6 percent of Che total
significant rainfall would have Co be accounted for as inflow. It must also
be noted that this simple volumetric analysis only considers average
conditions, i.e. 0.51 inches of rainfall per significant rainfall day. Note
from the precipitation record of Table 2 that an average of 20 days each year
were recorded with precipitation greater than this amount with a maximum daily
total of 1.41 inches for 1985 and 1.69 inches for 1986. It must also be
recognized that this analysis is only volumetric and does not account for the
maximum rate of runoff or rain-induced inflow. This maximum rate would be of
primary importance in the selection of control alternatives or design of
facilities. This parameter, however, can only be determined through a
detailed hydraulic analysis of the sewerage system.
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REFERENCES
1. Heaney, J. P., et. al. SCorm Water Management Model: Level 1 -
Preliminary Screening Procedures. USEPA Report No. EPA-600/2-76-275.
NTIS No. PB 259 916. October 1976.
2. Heaney, J. P., et. al. Nationwide Evaluation of Combined Sewer Overflows
and Urban Stormwater Discharges, Volume II: Cost Assessment and Impacts.
USEPA Report No. EPA-600/2-77-064. NTIS No. PB 266 005. March 1977.
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APPENDIX F
BRIEFING PAPER NO. 6
ONE-PLANT VS. TWO-PLANT
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• BRIEFING PAPER NO. 6
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ONE-PLANT VERSUS TWO-PLANTS
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• Supplemental Environmental Impact Statement
USEPA Contract No. 68-04-5035, D.O. No. 40
I Columbus Ohio Waste-water Treatment Facilities
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• Prepared By:
| SCIENCE APPLICATIONS INTERNATIONAL CORPORATION
| TRIAD ENGINEERING INCORPORATED
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ONE-PLANT VERSUS TWO-PLANTS
1. EXISTING FACILITIES
1.1 Jackson Pike Wastewater Treatment Plant
1.1.1 Major Interceptors
1.1.2 Preliminary Treatment (O.S.I.S. Flow)
1.L.3 Major Treatment Processes
1.2 Southerly Wastewater Treatment Plant
L.2.1 Major Interceptors
1.2.2 Interconnector Pump Station
1.2.3 Major Treatment Processes
2. IDENTIFICATION OF SYSTEM ALTERNATIVES
2.1 No Action Alternative
2.2 Upgrade the Existing Facilities
2.3 Eliminate Jackson Pike, Upgrade and Expand Southerly
3. DEVELOPMENT AND EVALUATION OF SYSTEM ALTERNATIVE COMPONENTS
3.1 Interconnector/Headworks
3.1.1 One-Plant System Alternative
3.1.2 Two-Plant System Alternative
3.2 Wet Stream Treatment
3.2.1 One-Plant System Alternative
3.2.1.1 Primary Treatment
3.2.1.2 Secondary Treatment
3.2.1.3 Post Treatment
3.2.2 Two-Plant System Alternative
3.2.2.1 Primary Treatment
3.2.2.2 Secondary Treatment
3.2.2.3 Post Treatment
3.3 Solids Handling and Disposal
3.3.1 One-Plant System Alternative
3.3.2 Two-Plant System Alternative
4. EVALUATION OF SYSTEM ALTERNATIVES
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INTRODUCTION
Under the direction of USEPA, a series of briefing papers are being
prepared addressing key issues in the development of the Supplemental
Environmental Impact Statement for the Columbus, Ohio, Wastewater Treatment
Facilities. The briefing papers form the basis of discussions between USEPA
and their consultant to resolve important issues. The following paragraphs
present the background of the facility planning process, a description of the
briefing papers, and the purpose of this paper on one-plant versus two-plants.
FACILITY PLANNING PROCESS
At the time this paper was prepared (July-August 1987) the city of
Columbus was proceeding to implement improvements at the Jackson Pike and
Southerly Wastewater Treatment Plants to comply with more stringent effluent
standards which must be met by July 1, 1988. These improvements were based
on the consolidation of wastewater treatment operations at the Southerly
plant. This one-plant alternative is a change from the two-plant operation
proposed by the city in the 1970's and evaluated in the 1979 EIS.
The development and documentation of wastewater treatment process and
sludge management alternatives for the Columbus metropolitan area has been an
extended and iterative process. The design and construction of various
system components have progressed, because of the 1988 deadline, while
planning issues continue to be resolved. As a result, numerous documents have
been prepared which occasionally revise a previously established course of
direction.
\
The concurrent resolution of planning issues and implementation of
various project components has made preparation of the EIS more difficult
because final facility plan recommendations are not available in a single
document.
F-l
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BRIEFING PAPERS -
To facilitate preparation of the EIS, a series of briefing papers are
being developed. The purpose of the briefing papers is to allow USEPA to
review the work of the EIS consultant and to identify supplemental information
necessary for the preparation of the EIS. Six briefing papers are being
prepared as follows:
• Flows and Loads
• Sludge Management
• CSO
• Process Selection
• One Plant vs. Two Plant (Alternative Analysis)
• O&M and Capital Costs
The specific focus of each briefing paper will be different. However,
the general scope of the papers will adhere to the following format:
• Existing conditions will be documented.
• Evaluations, conclusions, and recommendations of the facilities
planning process will be reviewed using available documentation.
• Where appropriate, an independent evaluation of the future situation
and viable alternatives will be prepared.
• The facility plan and EIS briefing paper conclusions will be compared.
The briefing paper process is intended to:
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• Prompt the resolution of any data deficiencies.
• Clearly establish and define existing and future conditions.
• Identify the final recommended plan which the city desires to implement.
• Provide a data base of sufficient detail to allow preparation of the
draft EIS.
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ONE-PLANT VS. TWO-PLANTS
This briefing paper evaluates the comprehensive wastewater management
alternatives in light of previous biological process, solids handling, and
cost analyses. The briefing paper is divided into four sections as follows:
Section 1 - Existing Facilities
This section discusses the facilities which existed at the Jackson Pike
and Southerly WWTPs prior to implementing construction for Project 88.
Section 2 - System Alternatives
Section 2 provides a description of the one-plant and two-plant
alternatives.
Section 3 - Development and Evaluation of System Alternative Components
Section 3 summarizes the facilities required for each process under the
one-plant and two-plant alternatives. Costs are included for all facilities.
Section 4 - Evaluation of System Alternatives
This section provides a technical evaluation of the one-plant and two-
plant alternatives based on present worth cost, reliability, flexibility,
iraplementability, and operational ease.
F-3
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1. EXISTING FACILITIES
This section describes the Jackson Pike and Southerly Wastewater
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Treatment Plants (WWTP). Figure 1-1 shows the locations of the two treatment I
plants and the Southwesterly Compost Facility within the planning area.
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1.1 JACKSON PIKE WASTEWATER TREATMENT PLANT
The Jackson Pike WWTP began operation in 1937. The plant was modernized •
and expanded in capacity in the raid-fifties. Currently (prior to Project 88) ™
there are two parallel flow trains for wet stream treatment consisting of
preaeration, primary settling, aeration, and final clarification. The
original train is called Plant A and the newer train is called Plant B. The
two trains operate relatively independently of each other during liquid •
processing but share sludge handling facilities.
1.1.1 Major Interceptors
Wastewater arrives at the Jackson Pike plant via the 108-inch diameter •
Olentangy-Scioto Interceptor Sewer (O.S.I.S.) and the 72-inch Big Run
Interceptor Sewer. The maximum hydraulic capability of the plant is 100 MGD. •
Current average day flows are approximately 84 MGD. The plant accepts all the ™
flow from the Big Run Interceptor but limits its acceptance of the O.S.I.S.
flow so the hydraulic capability of the plant will not be exceeded. The major
diversion point for the O.S.I.S. flows is at the Whit tier Street Storm Standby
Tanks.
Seven miles of 150-inch and 156-inch diameter gravity sewer currently
\
exists between the Jackson Pike and Southerly treatment plants. It begins
3,000 feet from the Jackson Pike WWTP and connects with a pump station on the
west side of the Scioto River near the Southerly WWTP. In September of 1986,
USEPA provided funding for construction of the remaining 3000 feet of the
sewer (Figure 1-2). This will complete the Interconnector Sewer between the
two plants. Included in the north end construction will be a diversion
chamber which will connect the Interconnector Sewer with the O.S.I.S. north of
F-4
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JACKSON PIKE WWTP
SOUTHERLY WWTP
APPROXIMATE SCALE: 1 INCH - 4.12 MILES
SOUTHWESTERLY COMPOST FACILITY
PLANNING AREA BOUNDARY ... ,
FIGURE 1-1
PLANNING AREA
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JACKSON PIKE WASTEWATER TREATMENT PLANT
PROPOSED 150"
INTERCONNECTOR EXTENSION
& 8" SLUDGE LINE EXTENSION
SOURCE: REVISED FACILITY PLAN UPDATE
F-6
FIGURE 1-2
NORTH END INTERCONNECTORl
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Jackson Pike. These improvements will allow Che flow to Jackson Pike to be
controlled by diverting excess flows to Southerly.
1.1.2 Preliminary Treatment (O.S.I.S. Flow)
Preliminary treatment is provided for flows entering Jackson Pike through
the O.S.I.S. at a facility called the Sewer Maintenance Yard which is located
approximately one mile north of Jackson Pike. These preliminary treatment
facilities were constructed in 1948. They are rated at a capacity of 160 MGD
and provide preliminary screening and grit removal for flows in the O.S.I.S.
prior to their arrival at Jackson Pike.
1.1.3 Major Treatment Processes
The Jackson Pike WWTP consists of the following major treatment
processes:
• Preliminary Treatment
• Primary Treatment
* Secondary Treatment
• Disinfection
• Solids Handling
• Solids Disposal
Figure 1-3 shows a flow schematic of the Jackson Pike WWTP. Table 1-1
presents the equipment sizes and the capacities for each unit process.
1.2 SOUTHERLY WASTEWATER TREATMENT PLANT
The Southerly WWTP began operation in 1967 with a single train. In the
early seventies, an additional wet stream train was added. The original train
is termed the Center Section. The newer train is called the West Section.
F-7
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1.2.1 Major Interceptors
Southerly receives approximately 50 to 60 MGD via the Big Walnut Sanitary
Outfall Sewer which serves the northeast, east, and southeast portions of
Columbus and Franklin County. An additional 5 MGD of flow is carried to
Southerly by the Interconnector Sewer which serves a portion of western
Columbus. The Southerly WWTP only accepts the amount of flow that it can
successfully treat and bypasses the remaining flow. Plant records show that
bypassing occurs when treated flows are as low as 54 MGD. At other times
treated flows can be as high as 90 MGD and no bypassing is reported. Excess
flow can be diverted to the Scioto River through a 108-inch diameter bypass
sewer at the plant's influent regulator chamber.
1.2.2 Interconnector Pump Station
The purpose of the Interconnector Pump Station is to pump flows from the
Interconnector across the Scioto River to the Southerly WWTP. The Intercon-
nector Pump Station is located on the south end of the Interconnector near
Southerly (Figure 1-4). Flows from the 156-inch Interconnector Sewer enter a
58-foot wide by 25-foot long by 16-foot deep chamber to be distributed to
three channels containing coarse bar racks and mechanically-cleaned bar
screens. Each channel is 6 feet wide by 30 feet long by 33 feet high. Flows
from the screening channels enter a 20-foot wide by 66-foot long by 23-foot
high wet well and are pumped by two 20 MGD and two 30 MGD extended shaft
centrifugal pumps through one 36-inch and one 48-inch force main to the
Southerly headworks.
1.2.3 Major Treatment Processes
The Southerly WWTP consists of the following major treatment processes:
• Preliminary Treatment
• Primary Treatment
• Secondary Treatment
• Disinfection
F-ll
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• Solids Handling
• Solids Disposal
Figure 1-5 shows a flow schematic of the Southerly WWTP. Table 1-2
provides sizings and capacities of individual unit treatment processes.
F-12
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2. IDENTIFICATION OF SYSTEM ALTERNATIVES
The current wastewater treatment facilities for the Columbus metropolitan
area are the Jackson Pike and Southerly Wastewater Treatment Plants (WWTP)
(See Figure 1-1.) Upgrading and expansion of one or both of these facilities
is required to meet federal effluent limitations. Thus, the following three
wastewater system alternatives have been selected to be evaluated for
preferred treatment.
• No action.
• Upgrade the existing facilities.
• Eliminate Jackson Pike, upgrade and expand Southerly.
The following sections discuss these three alternatives.
2.1 NO ACTION ALTERNATIVE
The development of a no action alternative is consistent with EPA
guidelines for preparing an EIS. A no-action alternative cannot be eliminated
during a preliminary screening. It must be included in a detailed evaluation
of alternatives. This is because it serves as a baseline when comparing and
evaluating action alternatives.
The no action alternative would involve normal maintenance but no
improvement to the existing facilities. Failure to rehabilitate and upgrade
the existing facilities will result in permit violations. This may result
in violations of water quality standards for receiving waters and possible
public health problems in the Columbus metropolitan area.
New NPDES permit limits have been established for the Columbus wastewater
treatment plants which they must be in compliance with by July 1, of 1988. The
plants are currently operating under interim limits. The Columbus wastewater
treatment plants, without improvements, cannot meet the new NPDES permit
limits. The new permits are more stringent with respect to CBOD^, TSS, and
F-16
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fecal coliform limits. The permits also include a limit for ammonia and a
minimum requirement for dissolved oxygen. An inability to meet permit require-
ments may result in sanctions by OEPA and USEPA that could have adverse social
and economic impacts in the facilities planning area.
2.2 UPGRADE THE EXISTING FACILITIES
This alternative, which is consistent with current operation, was
evaluated by the city in the facility plan. This alternative will be referred
to as the two-plant alternative. In this alternative, the existing treatment
plant sites will be maintained. Each plant will be rehabilitated and expanded
as necessary to provide advanced wastewater treatment on site for wastewater
flows expected through the year 2008. Due to site limitations and existing
hydraulic constraints at Jackson Pike, the city maintains that the wet stream
treatment capacity cannot be expanded. However, the existing facilities can
be upgraded to provide necessary treatment to meet proposed effluent require-
ments. Average flows in excess of 70 MGD and peak flows in excess of 100 MGD
at Jackson Pike would be diverted to Southerly via the Interconnector Sewer.
Figure 2-1 provides a flow schematic for the two-plant alternative.
2.3 ELIMINATE JACKSON PIKE, UPGRADE AND EXPAND SOUTHERLY
This alternative was evaluated and recommended by the City in the
facility plan. Under this alternative, also called the one-plant alternative,
Jackson Pike would be phased out and all flows would be diverted to Southerly
via the Interconnector Sewer. Expansion and rehabilitation of the existing
facilities at Southerly would be required. Figure 2-2 provides a flow
schematic for the one-plant alternative.
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3. DEVELOPMENT AND EVALUATION OF SYSTEM ALTERNATIVE COMPONENTS
This section presents the recommended process components and the
facilities required to implement the one-plant and two-plant system
alternatives. The components which will be discussed include the following:
• Interconnector/Headworks
• Wet Stream Treatment
• Solids Handling and Disposal
The Interconnector component involves options for conveyance between the
two WWTPs. Included in the headworks are the coarse bar racks, mechanically
cleaned bar screens, aerated grit chambers and pumps. Wet stream treatment
includes primary, secondary, and post treatment. Solids components include
thickening, processing, disposal, and reuse processes.
Secondary treatment and solids handling and disposal have been evaluated
in previous briefing papers. Therefore, this briefing paper will summarize
the recommendations of those papers.
The Interconnector, headworks, primary treatment, and post treatment are
presented for the first time in this briefing paper. An evaluation of
available options is contained herein. They will be discussed in greater
detail than secondary treatment and solids handling and disposal.
Recommended facility sizings in this paper are based on the flows and
loads developed in Briefing Paper No. 1. Costs are consistent with those
costs presented in Briefing Paper No. 4.
3.1 INTERCONNECTOR/HEADWORKS
The Interconnector and headworks alternatives are being discussed
together since they directly affect one another.
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The 150-inch to 156-inch Interconnector Sewer runs in a north-south
direction between Jackson Pike and Southerly along the west side of the Scioto
River. The south end connects to the Interconnector Pump Station. The
Interconnector Pump Station, with a firm capacity of 70 MGD, pumps the flow
across the Scioto River to Southerly through a 48-inch force main and a
36-inch force main.
The north end of the Interconnector Sewer is incomplete. However,
funding has been provided for its completion. The remaining segment will be
constructed along the west and north side of Jackson Pike (Figure 1-2). A
diversion chamber will be built connecting the Interconnector with the
O.S.I.S. This will allow regulation of flows to Jackson Pike and diversion of
flows to Southerly.
The existing Southerly headworks are rated at a capacity of 170 MGD. The
headworks consist of coarse and fine screening, pumping, and aerated grit
removal. The Jackson Pike headworks are rated at a capacity of 165 MGD. They
consist of fine screening and pumping. Preliminary treatment is provided for
flows entering Jackson Pike through the O.S.I.S. at the Sewer Maintenance
Yard. These preliminary treatment facilities are rated at a capacity of
160 MGD and provide screening and grit removal for flows in the O.S.I.S. prior
to their arrival at Jackson Pike.
3.1.1 One-Plant System Alternative
Under the one-plant system alternative, the Jackson Pike plant would be
phased out of service and all flows tributary to Jackson Pike would be
conveyed to Southerly via the Interconnector Sewer. In order to convey the
Jackson Pike flows to Southerly, the south end of the Interconnector and the
Southerly headworks capacity must be expanded.
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The Interconnected currently conveys approximately 5 MGD to Southerly
from a connection at Grove City. Under the one-plant system alternative, it
would be required to convey an additional 132 MGD from Jackson Pike
(Figure 2-2). This total flow exceeds the 70 MGD capacity of the existing
pump station and force mains. Alternatives for expansion which were evaluated
by the city include the following:
• Option A - additional pumping facilities and force mains
-» Option B - extension of the 156-inch gravity Interconnector to
Southerly
Option A consists of increasing the current 70 MGD capacity to 150 MGD by
construction of a new pumping facility on the south side of the existing pump
station, and by constructing one new 48-inch and one new 36-inch force main
parallel to the existing force mains to the Southerly headworks. The pump
station expansion will include the addition of three, 30 MGD submersible
centrifugal pumps and motors, three mechanical bar screens, and a screenings
conveyor system.
Option B consists of extending the 156-inch Interconnector Sewer to the
Southerly WWTP. Four 78-inch pipes would be used for the Scioto River
crossing to avoid the construction of a low head dam.
Under the one-plant alternative, the existing Southerly headworks would
not be able to handle the combined peak flow of 231 MGD (i.e. 99 MGD from
Southerly and 132 MGD from Jackson Pike).
The headworks options are affected by the Interconnector option selected.
The potential options available are:
• Option A-l - Expand existing headworks.
• Option B-l - Construct separate headworks for the Interconnector flows.
• Option B-2 - Construct new headworks for all flow.
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If Interconnector Alternative A is selected, the flows from the Big
Walnut Interceptor and the Interconnector would arrive at the plant at the
same elevation. Therefore, the existing headworks could be expanded to handle
all of the flow. Expansion would include additional pumps, screens, and grit
chambers. This option will be known as Option A-l.
If Interconnector Option B is selected, the gravity sewer will enter the
Southerly headworks approximately eight feet lower than the Big Walnut
Interceptor. This results in the need for separate headworks (Option B-l) for
the gravity Interconnector or completely new headworks (Option B-2) to handle
the flows from both sewers.
Option B-l consists of utilizing the existing 170 MGD headworks at
Southerly for handling the flows from the Big Walnut Interceptor and
constructing new 150 MGD headworks for handling the Interconnector flows. The
new Interconnector headworks will be located adjacent to the existing
headworks. They will include coarse bar racks, raw pumping, followed by
mechanical screening and aerated grit removal; all designed for 150 MGD.
Mixing of the Interconnector and Big Walnut flows would follow aerated grit
removal.
Option B-2 involves constructing completely new headworks which include a
mixing chamber, coarse bar racks, pumping, and aerated grit chambers. The
flows from the Big Walnut Interceptor and the Interconnector would combine in
a mixing chamber and be conveyed through manually cleaned bar racks. The
combined flow will then enter a wet well to be pumped to mechanical bar
screens followed by aerated grit chambers. The new headworks will be designed
for a peak process flow of 231 MGD. The combined costs for the
Interconnector/headworks alternatives are presented in Table 3-1.
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TABLE 3-1. INTERCONNECTOR/HEADWORKS ALTERNATIVE
PRESENT WORTH COSTS
Interconnector
Headworks
TOTAL
Option A/A-1
$14,058,000
$17,006,000
$31,064,000
Option B/B-1
$4,432,000
$25,847,000
$30,279,000
Option B/B-2
$4,432,000
$30,496,000
$34,928,000
Option B/B-1 exhibics the lowest present worth cost. However, practically
speaking the present worth of A/A-1 is equal to B/B-1. Reliability, implemen-
tability, and ease of operation must also be considered when selecting the best
alternative.
The gravity sewer options (B/B-1 and B/B-2) are more reliable than the
force main option (A/A-1) because there is less chance that the gravity sewer
will rupture. Also, gravity failure normally results in infiltration to the
conduit; while force mains exfiltrate to the environment. In addition, the
gravity sewer does not rely on the operation of a pumping facility to function
properly. Therefore, it would be easier to operate and maintain. However,
separate headworks are needed for option B/B-1 which would require additional
operation and maintenance time.
The force mains, on the other hand, may not require as deep of an
excavation as the gravity sewer; and therefore, they would be easier to
implement.
Based on the cost and reliability of Option B/B-1 (gravity), it is the
recommended Interconnector/headworks option for the one-plant alternative.
3.1.2 Two-Plant System Alternative
The two-plant alternative does not require any expansion of the
Interconnector or any additional headworks at the Southerly WWTP. New
headworks are required at the Jackson Pike WWTP. The total present worth cost
of the headworks is $14,170,000.
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3.2 WET STREAM TREATMENT
Briefing Paper No. 3 - Process Selection presented a detailed evaluation
of secondary treatment alternatives and provided recommendations for secondary
treatment facilities under each system alternative. In light of these
recommendations, this section will summarize the facilities required under
each system alternative for the following processes:
• Primary treatment
• Secondary treatment
• Post treatment
Secondary treatment recommendations will be consistent with the
conclusion of the process selection breifing paper. Primary treatment and
post treatment are being presented here for the first time.
3.2.1 One-Plant System Alternative
The one-plant alternative requires upgrading and expansion of the
Southerly plant to handle ail flows from the Jackson Pike and Southerly
service areas. It was concluded in the process selection briefing paper that
in addition to the two existing trains, one additional wet stream treatment
train would be required at the Southerly WWTP. Figure 2-2 shows how the flow
will be distributed between the three trains.
3.2.1.1 Primary Treatment
The Southerly WWTP currently has primary treatment consisting of
preaeration and primary settling. Preaeration of wastewater prior to primary
settling is done for odor control, to prevent septicity, and to improve
subsequent settling. Little or no BOD reduction occurs in the preaeration
tanks. However, preaeration does increase the removal of BOD and suspended
solids in the primary tanks. Primary settling should remove 25 Co 40 percent
of the influent BOD and 50 to 70 percent of the suspended solids.
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The Southerly WWTP currently has four preaeration tanks in each of the
Center and West Trains. These preaeration tanks are adequate for providing
treatment for the flows in these two trains under the one-plant alternative.
However, an additional East Train is required under the one-plant alternative.
As presented in Figure 2-2, this new East Train will provide treatment for an
average flow of 66 MGD and a peak process flow of 99 MGD. Assuming a
detention time of 30 minutes at average flow, four additional preaeration
tanks are required in the new East Train. These new tanks are the same size
as the tanks in the existing trains.
The Southerly WWTP has four primary settling tanks in each of the
existing Center and West Trains. These tanks have adequate primary settling
capacity for the average and peak flows allocated to these trains under the
one-plant alternative. However, additional tanks are required for the new
East Train. Assuming a surface loading rate of 1000 gallons per day per
square foot at average flow as recommended by Ten States Standards, 66,000
square feet of surface area is required. This surface area can be provided by
adding four new 150-foot diameter circular clarifiers.
3.2.1.2 Secondary Treatment
The form of secondary treatment currently provided at the Southerly WWTP
is conventional single-stage activated sludge. This process includes
rectangular aeration tanks followed by rectangular secondary clarifiers. The
plant was designed based on NPDES permit limits of 30 rag/1 for CBOD^ and TSS.
The CBODc and TSS limits have become more stringent and an ammonia standard
has been added Co both permits. As a result of these changes, the plants are
not capable of treating design flows to the more stringent permit limits.
Through the course of the facilities planning process for the Columbus
wastewater treatment facilities, other alternatives to the conventional
activated sludge process have been proposed. The 1979 EIS recommended a
trickling filter process followed by activated sludge for the Jackson Pike
plant. The Facilities Plan Update (FPU) and Revised Facilities Plan Update
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recommended a semi-aerobic treatment process. The Process Selection Briefing
Paper evaluated the semi-aerobic, trickling filter/activated sludge, and
single-stage activated sludge processes and recommended utilizing the semi-
aerobic process at both plants.
The semi-aerobic process is a modified form of the activated sludge
process. The process consists of a non-aerated reaction zone ahead of an
aerated activated sludge zone. The non-aerated zone may be anoxic (nitrates
are present), anaerobic (no oxygen or nitrates present), or a combination of
both. The purpose of the anaerobic zone is to control bulking sludge. The
anaerobic zone may change to anoxic depending on the level and concentration
of nitrates in the wastewater. In the anoxic zone denitrification occurs.
Denitrification is a process by which nitrates are converted into nitrogen
gas.
The only physical differences between the semi-aerobic process and the
conventional activated sludge process is an internal mixed liquor recycle loop
and the addition of baffles to compartmentalize the aeration tanks. The
baffles are incorporated into the design to prevent back-mixing from the
aerated zone to the anaerobic zone. The internal recycle loop is used to
bring nitrates back to the anoxic zone and thus cause denitrification to
occur.
Under the one-plant scenario, the Southerly WWTP would be upgraded to
handle all flows from the Columbus service area. The Southerly WWTP currently
has a West Train and a Center Train. The West Train has six aeration tanks
which are capable of treating an average design flow of 44 MGD. The Center
Train has four aeration tanks which are capable of treating an average design
flow of 29 MGD. These flows are based on the design parameters of the semi-
aerobic process.
The 2008 average design flow for the one-plant alternative is 154 MGD.
This will require an additional aeration basin capacity of 81 MGD. This can
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be provided by adding two tanks to the existing Center Train and by construct-
ing a new East Train consisting of nine aeration basins. Figure 2-2 shows how
the flow is allocated to each train.
The existing aeration basins will require some modifications to allow
them to be operated in the semi-aerobic mode. Two baffles must be installed
in the first bay of each of the ten existing tanks and an internal mixed
liquor recycle loop must also be added to each tank.
The existing rectangular clarifiers will be replaced by six new circular
clarifiers. New circular clarifiers were recommended for the Southerly WWTP
due to the high mixed liquor concentration which must be maintained for
nitrification and the difficulty associated with settling a nitrified sludge.
In addition to the six new secondary clarifiers for the existing Center
and West Trains, four new circular clarifiers are required for secondary
settling in the new East Train.
3.2.1.3 Post Treatment
The current post treatment provided at the Southerly WWTP is
chlorination. The Southerly WWTP has an earthen contact basin with internal
baffles. This basin was designed as a temporary structure until a decision on
tertiary treatment could be finalized. Since new regulations require
disinfection, Southerly needs permanent facilities.
Southerly would require two new chlorine contact tanks sized at 81 feet
by 200 feet by 10 feet side water depth. Dechlorination is also required to
limit the chlorine residual in the effluent. Post aeration will take place in
the final pass of the tanks to maintain a dissolved oxygen in the effluent of
7.0 mg/1.
Table 3-4 summarizes the wet stream facilities required under the one-
plant alternative and the associated costs.
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TABLE 3-4
WET STREAM TREATMENT
(Southerly One-Plant)
Facilities and Estimated Costs
PREAERATION $ 5,905,000
Eight existing tanks; 112.7 ft x 26 ft x 15.5 ft SWD
Four new tanks; 112.7 ft x 25.5 ft x 15.5 ft SWD
PRIMARY SETTLING 13,590,000
Four existing tanks; 80 ft x 165 ft x 10 ft SWD
Four existing tanks; 100 ft x 170 ft x 10 ft SWD
Four new tanks; 150 ft dia. x 15 ft SWD
AERATION 46,533,000
Ten existing tanks; 26 ft x 900 ft x 15 ft SWD
Eleven new tanks; 26 ft x 900 ft x 15 ft SWD
FINAL SETTLING 35,462,000
Demolish existing tanks
Ten new tanks; 200 ft dia. x 15 ft SWD
CHLORINATION/DECHLORINATION/POST AERATION 3,000,000
Two new tanks; 81 ft x 200 ft x 10 ft SWD
including mixers, chlorinators, evaporators, and sulfonators.
Post Aeration takes place in the final pass of
the chlorine contact tanks.
TOTAL CAPITAL COSTS $104,490,000
ANNUAL O&M COSTS 5,224,000
TOTAL PRESENT WORTH $144,504,000
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3.2.2 Two-Plant System Alternative
The two plant alternative requires upgrading of both plants and minor
expansion of the Southerly plant. No additional wet stream treatment trains
are required at either plant. Flows are distributed to each of the plants as
shown in Figure 2-1.
3.2.2.1 Primary Treatment
Under the two-plant alternative, the Southerly WWTP has adequate primary
settling and preaeration capacity. However, upgrading of the existing
facilities is required.
The Jackson Pike WWTP currently has two preaeration tanks in each of the
two trains, Plant A and Plant B. The two tanks in Plant A provide 1.05 MG of
total volume. The two tanks in Plant B provide 0.66 MG of total volume.
These tanks are capable of treating an average flow of 70 MGD.
The Jackson Pike WWTP has four primary settling tanks in each existing
train, Plant A and Plant B. These tanks are also adequate to treat an average
flow of 70 MGD.
3.2.2.2 Secondary Treatment
The semi-aerobic process is recommended at both plants under the
two-plant alternative.
Under the two-plant option the Southerly WWTP will be required to treat
an average flow of 84 MGD and a peak process flow of 131 MGD. These flows
include 18 MGD under average conditions and 32 MGD under peak conditions being
diverted from Jackson Pike. The Jackson Pike WWTP is limited to an average
flow of 70 MGD and a peak process flow of 100 MGD.
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In accordance with the evaluation presented in the Process Selection
Briefing Paper, only two additional aeration basins are required in the Center
Train at Southerly under the two-plant alternative. Then each train would
have six basins and could treat an average flow of 42 MGD and a peak process
flow of 65.5 MGD (see Figure 2-1).
The existing rectangular clarifiers should be demolished and replaced
with six new circular clarifiers.
The Jackson Pike WWTP is hydraulically limited to a peak process flow of
100 MGD. Any peak flows in excess of this flow would be diverted to the
Southerly WWTP under a two-plant alternative. An average flow of 88 MGD was
projected for the 2008 design year. However, in evaluating the existing
facilities, the aeration facilities were found to be limited to 70 MGD average
flow.
At an average flow of 70 MGD and a peak process flow of 100 MGD, the
existing aeration facilties at Jackson Pike have adequate capacity. However,
extensive rehabilitation and the addition of baffles and an internal mixed
liquor recycle system would be required to operate in the semi-aerobic mode.
The final clarifiers, on the other hand, are not sufficient to treat a peak
process flow of 100 MGD. Two additional rectangular clarifiers would be necessary.
3.2.2.3 Post Treatment
Under the two-plant alternative, the Jackson Pike and Southerly WWTPs
would require new chlorine contact tanks. As discussed in the previous
section, Southerly has a temporary contact basin. Jackson Pike performs
disinfection by injection of chlorine into the discharge pipeline. Under the
two-plant alternative, Southerly would need two new tanks sized at 150 feet by
64 feet by 10 feet side water depth. Jackson Pike would need two new tanks
sized at 100 feet by 70 feet by 10 feet side water depth. Dechlorination
would also be employed. Post aeration would take place in the final pass of
the tanks.
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Tables 3-5 and 3-6 present a summary of the required wet stream treatment
facilities and the associated costs for the Southerly WWTP and the Jackson
Pike WWTP, respectively.
3.3 SOLIDS HANDLING AND DISPOSAL
This section summarizes the recommended solids handling and disposal
components for the one-plant system alternative and the two-plant system
alternative. These recommendations were identified in the solids handling
briefing paper after a thorough evaluation of solids management options for
each plant.
3-3.1 One-Plant System Alternative
The solids handling and disposal scheme identified for Southerly under
the one-plant system alternative is shown in Figure 3-1. This handling and
disposal scheme includes the following sludge processes:
• Gravity thickening of primary sludge
• Centrifuge thickening of waste-activated sludge
• Thickened sludge storage and blending
• Stabilization by anaerobic digestion
• Centrifuge dewatering
• Composting
• Incineration
• Land Application
Dewatered sludge would be disposed of as follows:
• 25 percent would be composted and distributed as a soil conditioner.
Sludge sent to compost would not go through the digestion process.
• 25 percent would be land applied as a fertilizer to agricultural
acreage within a reasonable distance from the plant.
• 50 percent would be incinerated, and the ash product would be landfilled.
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TABLE 3-5
WET STREAM TREATMENT
(Southerly Two-Plant)
Facilities and Estimated Costs
PREAERATION $ 1,533,000
Eight existing tanks; 112.7 ft x 26 ft x 15.5 ft SWD
PRIMARY SETTLING 4,717,000
Four existing tanks; 80 ft x 165 ft x 10 ft SWD
Four existing tanks; 100 ft x 170 ft x 10 ft SWD
AERATION 12,284,000
JL xvyii
Ten existing tanks; 26 ft x 900 ft x 15 ft SWD
Two new tanks; 26 ft x 900 ft x 15 ft SWD
FINAL SETTLING 20,521,000
Demolish existing tanks
Six new tanks; 190 ft dia. x 15 ft SWD
CHLORINATION/DECHLORINATION/POST AERATION 1,800,000
Two new tanks; 150 ft x 64 ft x 10 ft SWD
including mixers, chlorinators, evaporators, and sulfonators.
Post aeration takes place in the final pass
of the chlorine contact tanks.
TOTAL CAPITAL COSTS $40,855,000
ANNUAL O&M COSTS 2,382,000
TOTAL PRESENT WORTH $61,562,000
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TABLE 3-6
WET STREAM TREATMENT
(Jackson Pike Two-Plant)
Facilities and Estimated Costs
PREAERATION $ 3,750,000
Two existing tanks; 180 ft x 26 ft x 15 ft SWD
Two existing tanks; 113 ft x 26 ft x 15 ft SWD
Building renovation
PRIMARY SETTLING 7,372,000
Eight existing tanks; 150 ft x 80 ft x 10 ft SWD
Control building renovation
AERATION 22,502,000
Twelve existing tanks; 900 ft x 26 ft x 15 ft SWD
Control building renovation
FINAL SETTLING 8,691,000
Twelve existing tanks; 153 ft x 60 ft x 12.5 ft SWD
Two new tanks; 153 ft x 60 ft x 12.5 ft SWD
CHLORINATION/DECHLORINATION/POST AERATION 1,300,000
Two new tanks; 100 ft x 70 ft x 10 ft SWD
including mixers, chlorinators, evaporators, and sulfonators.
Post aeration takes place in the final pass of
the chlorine contact tanks.
TOTAL CAPITAL COSTS $43,615,000
ANNUAL O&M COSTS 2,648,000
TOTAL PRESENT WORTH $66,722,000
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This alternative provides a great deal of flexibility for disposal. It
offers continuation of the existing incineration and composting processes at
Southerly and introduces land application as a disposal process. Table 3-7
presents the required sizing and associated costs of the sludge management
facilities for the one-plant system alternative.
3.3.2 Two Plant System Alternative
The recommended solids handling and disposal scheme for Southerly under a
two-plant system alternative is the same as that for a one-plant system
alternative. This scheme was previously described in Figure 3-1. Table 3-8
presents the sizing and costs of the required sludge management facilities for
Southerly under a two-plant system alternative.
The recommended solids handling and disposal scheme for Jackson Pike
under a two-plant alternative is presented in Figure 3-2. This alternative
includes the following sludge processes:
• Gravity thickening of primary sludge
• Centrifuge thickening of waste-activated sludge
• Thickened sludge storage and blending
• Stabilization by anaerobic digestion
• Centrifuge dewatering
• Incineration
• Land Application
Dewatered sludge would be disposed of as follows:
• 50 percent would be incinerated and the ash product landfilled
• 50 percent would be land appplied as a fertilizer to agricultural
acreage within a reasonable distance from the plant.
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TABLE 3-7
SOUTHERLY SLUDGE MANAGEMENT COMPONENTS
One-Plant System Alternative
Facilities and Estimated Costs
Gravity Thickening PS plus Dilution Water Pumping $5,070,000
Four (4) existing; 45-foot dia. x 17-foot SWD
Two (2) new; 85-foot dia. x 10-foot SWD
Centrifuge Thickening WAS 5,600,000
Four (4) existing; 250 gpm, 1250 Ib/hr
Four (4) new; 250 gpra, 1250 Ib/hr
Thickened Sludge Storage/Blend —
Existing Facilities Reused
Anaerobic Digestion 11,460,000
Six (6) existing; 85-foot dia. x 25.25-foot SWD
Four (4) new; 85-foot dia. x 25.25-foot SWD
Centrifuge Dewatering 21,040,000
Six (6) existing; 1000 Ib/hr
Nine (9) new; 1000 Ib/hr
Dewatered Sludge Storage
One (I) new; 400 cy plus material handling 1,300,000
Composting
Existing Facilities; 120 wet ton/day @ 20% solids
Incineration
Two (2) new; 8 hearth, 260 wet ton/day @ 20% solids
Rehabilitate existing 1,300,000
Landfill
Contract operations included with O&M —
\
Land Application —
Contract operations included with O&M
Capital Cost $45,770,000
Annual Operation and 6,230,000
Maintenance Cost
Present Worth (One-Plant) $90,710,000
F-37
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TABLE 3-8
SOUTHERLY SLUDGE MANAGEMENT COMPONENTS
Two-Plant System Alternative
Facilities and Estimated Costs
Gravity Thickening PS plus Dilution Water Pumping $2,520,000
Four (4) existing; 45-foot dia. x 17-foot SWD
Centrifuge Thickening WAS 2,000,000
Four (4) existing; 250 gpm, 1250 Ib/hr
One (1) new; 250 gpra, 1250 Ib/hr
Thickened Sludge Storage/Blend
Existing Facilities Reused
Anaerobic Digestion 4,280,000
Six (6) existing; 85-foot dia. x 25.25-foot SWD
Centrifuge Dewatering 5,120,000
Six (6) existing; 1000 Ib/hr
Two (2) new; 1000 Ib/hr
Dewatered Sludge Storage 1,300,000
One (1) new; 400 cy plus material handling
Composting
Existing Facilities; 120 wet ton/day @ 20% solids
Incineration
Two (2) new; 8 hearth, 260 wet ton/day @ 20% solids
Landfill
Contract operations included with O&M
Land Application —
Contract operations included with O&M
\
Capital Cost $15,220,000
Annual Operation and 3,340,000
Maintenance Cost
Present Worth (Two-Plant) $39,680,000
F-38
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LJ
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[NTRIFUGE
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F-39
-------
The difference between this alternative and the alternative recommended
for Southerly is that the Jackson Pike alternative does not include
composting. The recommended 50:50 disposal ratio between land application and
incineration is approximately consistent with current Jackson Pike disposal
practices. Table 3-9 provides a list of the required facilities for Jackson
Pike and their associated costs.
F-40
-------
TABLE 3-9
JACKSON PIKE SLUDGE MANAGEMENT COMPONENTS
Two-Plant System Alternative
Facilities and Estimated Costs
Gravity Thickening PS plus Dilution Water Pumping $1,967,000
Modify two (2) digesters; 85-foot dia. x 10-foot SWD
Centrifuge Thickening WAS 4,500,000
Two (2) existing; 500 gpm
One (1) new; 500 gpm
Thickened Sludge Storage/Blend
Existing Facilities Reused
Anaerobic Digestion 9,170,000
Six (6) existing; 85-foot dia. x 23.5-foot SWD
Centrifuge Dewatering 490,000
Six (6) existing; 1200 Ib/hr
Incineration
Two (2) existing, 7 hearth, 200 wet ton/day @ 20% solids 3,600,000
Landfill
Contract operations included with O&M
Land Application
Contract operations included with O&M —
Capital Cost $19,727,000
Annual Operation and 3,070,000
Maintenance Cost
Present Worth (Two-Plant) $45,827,000
F-41
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4. EVALUATION OF SYSTEM ALTERNATIVES
This section evaluates the one-plant and two-plant system alternatives
based on cost, reliability, fexibility, implementability, and operational
ease.
Table 4-1 presents the capital, annual O&M, and total present worth costs
for the one-plant and two-plant system alternatives.
TABLE 4-1. SYSTEM ALTERNATIVE COSTS
Total
Capital Annual O&M Present Worth
One-Plant [Southerly] 268,711,000 16,849,000 436,911,000
Two-Plant [So. and Jackson Pike] 207,076,000 19,078,000 397,016,000
Difference from One-Plant -61,635,000 +2,229,000 -39,895,000
Percent Difference -30 +13 -10
Details on the development of the costs in Table 4-1 are presented in
Briefing Paper No. 4 - Capital and O&M Costs.
The two-plant system alternative exhibits a total present worth cost
approximately 10 percent lower than the one-plant alternative.
Both the one-plant and two-plant alternatives are equal with respect to
their reliability in meeting final effluent limits. However, the two-plant
would be more reliable with respect to shock loads. Under the one-plant
alternative, a plant upset at Southerly could result in a significant loss of
biological treatment capacity and may cause a serious water quality problem.
However, if the shock and/or toxic load can only reach one of the two plants,
the impact may not be as severe.
The two-plant alternative is judged more flexible than the one-plant
alternative. With both facilities operational, the city would have more
flexibility to adapt to increased future flow, to meet more stringent effluent
limits, and to address combined sewer overflows. The two-plant alternative
F-42
-------
would leave more land available at Southerly for expansion. The two-plant
alternative would improve and upgrade Jackson Pike to provide a solid 100 MGD
treatment capacity. The two-plant alternative would allow for future
expansion of the Interconnector system to divert more flow to Southerly while
optimizing the use of the Jackson Pike facility.
The two-plant alternative would be easier to implement since the majority
of the facilities already exist. Most of the construction would consist of
rehabilitation of existing facilities. No expansion of the conveyance system
between the plants is required under this alternative.
The one-plant alternative would be easier to operate and maintain since
all facilities would be consolidated at one location.
A recommendation on a system alternative cannot be made based solely on
this technical evaluation. Environmental impacts must be considered prior to
making a recommendation.
F-43
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APPENDIX G
GRAPHS OF STORE! DATA
FOR DO, BOD, AND AMMONIA
FROM 1971-1986 AT SIX
STATIONS ON THE SCIOTO RIVER
BETWEEN JACKSON PIKE WWTP
AND CIRCLEVILLE, OHIO
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APPENDIX H
TABLES OF ENDANGERED SPECIES
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TABLE H-l. ENDANGERED FAUNA SPECIES KNOWN TO OCCUR IN THE
COLUMBUS FACILITIES PLANNING AREA, OHIO8
Species
Indiana bat
(Myotis sodalis)
Peregrin falcon
(Falco peregrinus)
Bald eagle (Haliaeetus
leucocephalus)
Kirtland's warbler
(Dendroica kirtlandii)
Upland sandpiper
(Bartramia longicauda)
Common tern (Sterna
Hirundo)
Four-toed salamander
(Hemidactyliumd scutatum)
Northern brook lamprey
(Icthyomyzon fossor)
Paddlefish (Polyodon
spathula)
Blacknose shiner
(Notropis heterolepis)
River redhorse
(Moxostoma carinatum)
State Federally
Endangered Endangered
X X
X X
X X
X X
X
X
X
X
X
X
X
Remarks
Habitat requirements are
not fully known.
Occurs as an uncommon
migrant .
Occurs as an uncommon
migrant .
Occurs as an uncommon
migrant .
May occur in suitable,
grassy habitat anywhere in
the country. Recent
records exist for Bolton
Field and Rickenbacker Air
Base.
Occurs as an uncommon
migrant .
Requires a bog-like
habitat. A recent record
exists for the northeastern
corner of the country.
Rare occurrence in Big
Walnut Creek and Big Run
(tributary of Olentangy
River) .
One specimen observed in
Scioto River below
Greenlawn Dam in 1976.
Population in Rocky Fork
Creek (tributary of Big
Walnut Creek, northeast
Franklin County).
Known population in Scioto
River and tributaries.
H-l
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TABLE H-l. ENDANGERED FAUNA SPECIES KNOWN TO OCCUR IN THE
COLUMBUS FACILITIES PLANNING AREA, OHIO3 (Continued)
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Species
State Federally
Endangered Endangered
Remarks
Slenderhead darter
(Percina phoxocephala)
Spotted darter
(Etheostoma Maculatum)
Lake Chubsucker
(Erimyzon succtta)
Shortnose gar
(Lepisosteus platostomius)
Mooneye
(Hiodon tergisus)0
Tippecanoe darter
(Ethestoma tippecanoe)
Scioto madtom
(Noturus trautmani)
d , e
Piping plover
(charadrius melodus)
Known population in Big
Walnut and Big Darby
Creeks.
Small population in
Olentangy River and Big
Walnut Creeks.
Collected just downstream
of FPA at Circleville.
Found only in Big Darby
Last seen at the Jackson
Pike Wastewater Treatment
plant in the 1940's.
'Source: Ohio Department of Natural Resources 1986, unless otherwise noted.
bSource: OEPA 1986a.
GSource: Yoder 1987; Ohio Department of Natural Resources 1986.
Source: Cavender 1986.
"Source: Multerer 1986.
£Source: Huff 1988
H-2
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TABLE H-2. LIST OF STATE AND FEDERALLY ENDANGERED PLANT SPECIES IN OHIO
Selaginella rupestris, Rock Spikemoss
Isoetes engelmannii, Appalachian Quillwort
Botrychium lanceolatum, Triangle Grape-fern
Ophioglossum engelmannii, Limestone Adder's-tongue
Trichomanes bpschianum, Appalachian Filmy Fern
Polypodium polypodioides, Little Gray Polypody
Dryopteris clintoniana, (D. cristata var. clintoniana) Clinton's Wood Fern
Sparganium androcladum, Keeled Bur-reed
Sparganium chlprocarpum, Small Bur-reed
Potamogeton filiformis, Filiform Pondweed
Potamogeton gramineus, Grass-like Pondweed
Potamogeton hillii, Hill's Pondweed
Potamogeton praelongus, White-stem Pondweed
Potamogeton robbinsii, Robbin's Pondweed
Potamogeton tennesseensis, Tennessee Pondweed
Scheuchzerialialustris, Scheuchzeria
Sagittaria graminea, Grass-leaf Arrowhead
Cinna latifolia, Northern Wood-reed
Danthonia compressa, Flattened Wild Oat Grass
Digitaria filiformis, Slender Finger-grass
Glyceria acutiflora, Sharp-glumed Manna-grass
Koeleria macrantha (K. cristata), Junegrass
Melica nitens, Three-flowered Melic
Muhlenbergia cuspidata, Plains Muhlenbergia
Oryzopsis asperifolia, Large-leaved Mountain-rice
Panicum bicknellii, Bicknell's Panic-grass
Panicum boreale, Northern Panic-grass
Panicum leibergii, Leiberg's Panic-grass
Panicum villosissimum, Villous Panic-grass
Panicum yadkinense, Spotted Panic-grass
Poa wolfii, Wolf's Bluegrass
Schizachne purpurascens, False Melic
Carex aquatilis, Leafy Tussock Sedge
Carex arctata, Drooping Wood Sedge
Carex argyrantha, Silvery Sedge
Carex atherodesT Wheat Sedge
Carex bebbii, Bebb's Sedge
Carex cryptolepis (C. flava var. fertilis), Little Yellow Sedge
Carex debilis var. debilis, Weak Sedge
Carex decomposita, Cypress-knee Sedge
Carex folliculata, Long Sedge
Carex garberi, Garber's Sedge
Carex gravida, Heavy Sedge
Carex haydenii, Hayden's Sedge
Carex louisianica, Louisiana Sedge
Carex nigromarginata, Black-margined Sedge
Carex ormpstachya, Stiff Broad-leaved Sedge
Carex pallescens, Pale Sedge
Carex sprengelTI, Sprengel's Sedge
Carex striatuIaT Lined Sedge
Cyperus acuminatus, Pale Umbrella-sedge
H-3
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TABLE H-2. LIST OF STATE AND FEDERALLY ENDANGERED PLANT SPECIES IN OHIO
(Continued)
Cyperus dipsaciformis, Teasel-sedge
Rhynchospora globularis, Grass-like Beak-rush
Scirpus expansus, Woodland Bulrush
Scirpus smithii, Smith's Bulrush
Scirpus subterminalis, Swaying Rush
Wolffiella floridanaT Wolffiella
Juncus interior, Inland Rush
Clintonia borealis, Bluehead-lily
Lilium philadelphicum, Wood-lily
Melanthium virginicum, Bunchflower
Nothoscordum bivalve, False Garlic
Smilax pulverulenta, Downy Carrion-flower
Streptopus roseus, Rose Twisted-stalk
Iris brevTcaulis, Leafy Blue Flag
Iris verna, Dwarf Iris
Sisyrinchium atlanticum, Atlantic Blue-Eyed-grass
Sisyrinchium montanum, Northern Blue-eyed-grass
Arethusa bulbosa, Dragon's-mouth
Coeloglossum viride (Habenaria viridis), Long-bracted Orchid
Corallorhiza trifida, Early Coral-root
Corallorhiza wisteriana, Spring Coral-root
Cypripedium calceolus var. parviflorum, Small Yellow Lady's-slipper
Cypripedium candidum, White Lady's-slipper
Hexalectris spicata, Crested Coral-root
Platanthera blephariglottis (Habenaria blephariglottis)> White Fringed Orchid
Spiranthes romanzoffiana,Hooded Ladies'-tresses
Populus balsamifera, Balsam Poplar
Populus heterophylla, Swamp Cottonwood
Salix caroliniana, Carolina Willow
Salix pedicellaris, Bog Willow
Myrica pensylvanica, Bayberry
Ulmus thomasii, Rock Elm
Urtica chamaedryoides, Spring Nettle
Polygonum cilinode, Mountain Bindweed
Pplygonum ramosissimum, Bushy Knotweed
ChenopodTum leptophyllum (sensu Fernald 1950), Slender Goosefoot
Froelichia floridana, Cottonweed
Arenaria patula, Spreading Sandwort
Silene caroliniana var. wherryi, Wherry's Catchfly
Nuphar variegatum, Bullhead Lily
Aconitum noveboracense, Northern Monkshood
Aconitum uncinatum, Southern Monkshood
Actaea rubra, Red Baneberry
Ranunculus pusillus, Low spearwort
Trollius~Iaxus, Spreading Globe-flower
Magnolia macrophylla, Bigleaf Magnolia
Magnolia tripetala, Umbrella Magnolia
Arabis divaricarpa, Limestone Rock-cress
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TABLE H-2. LIST OF STATE AND FEDERALLY ENDANGERED PLANT SPECIES IN OHIO
(Continued)
Arabis drummondii, Drummond's Rock-cress
Arabis patens, Spreading Rock-cress
Draba brachycarpa, Little Whitlow-grass
Draba cuneifolia, Wedge-leaf Whitlow-grass
Draba reptans, Carolina Whitlow-grass
Erysimum arkansanum (E. capitatum), Western Wall-flower
Drpsera intermedia, Spathulate-leaved Sundew
Ribes niissouriense, Missouri Gooseberry
Ribes rotundifolium, Appalachian Gooseberry
Ribes triste, Swamp Red Currant
Amelanchier sanguinea, Rock Serviceberry
Palibarda repens, Robin-run-away
PotentilTa arguta, Tall Cinquefoil
Prunus nigra, Canada Plum
Pyrus decora (Sorbus decora), Western Mountain-ash
Rubus setosus, Small Bristleberry
Astragalus neglectus, Cooper's Milk-vetch
Baptisia australis, Blue False Indigo
Desmodium illinoense, Prairie Tick-trefoil
Desmodium sessilifoTium, Sessile Tick-trefoil
Galactia volubilis, Milk-pea
Lathyrus venosus, Wild Pea
Oxalis montana (0. acetosella), White Wood-sorrel
Geranium bicknelTii^Bicknell's Crane's-bill
Polygala cruciata, Cross-leaved Milkwort
Polygala curtissii, Curtiss' Milkwort
Euphorbia serpens, Roundleaf Spurge
PhyllanThus caroliniensis, Carolina Leaf-flower
Paxistima canbyi,Cliff-green
Acer pensylvanicum, Striped Maple
Caenothus herbaceus (C. ovatus), Prairie Redroot
Hypericum denticuTatum, Coppery St. John's-wort
Hudsonia tomentosa, Beach-heather
Viola missouriensis, Missouri Violet
Viola nephrpphylla, Northern Bog Violet
Viola primulifolia, Primrose-leaved Violet
Viola tripartita yar. glaberrima (forma glaberrima), Wedge-leaf Violet
Viola walteri,"Walter's Violet
Arlia hispida, Bristly Sarsaparilla
Hydrocotyle umbellata, Navelwort
Ledum groenlandicum,~Labrador-tea
Rhododendron calendulaceum, Flame Azalea
Vaccinium myrtilloides, Velvet-leaf Blueberry
Vaccinium oxycoccos, Small Cranberry
Hottonia inflata, Featherfoil
Halesia"carolina, Silverbell
Styrax americanus, Snowbell
Gentiana puberulenta (G. puberula), Prairie Gentian
Gentiana saponaria, Soapwort Gentian
Cuscuta compacta, Sessile Dodder
Cynoglossum virginianum var. boreale (C. boreale), Northern Wild Comfrey
H-5
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TABLE H-2. LIST OF STATE AND FEDERALLY ENDANGERED PLANT SPECIES IN OHIO
(Continued)
Collinsonia verticillata (Micheliella verticillata), Early Stoneroot
Monarda punctata, Dotted Horsemint
Trichostema dichotomum var. lineare (T. setaceum), Narrow-leaved Bluecurls
Agalinis auriculata (Gerardia auriculata; Tomanthera auriculata), Ear-leaf
Foxglove
Agalinis purpurea var. parviflora (A. paupercula var. pauperula and var.
~~ -. be
borealis; Gerardia paupercula var. paupercula and var. borealis), Small
Purple Foxglove
Agalinis skinneriana (Gerardia skinneriana), Skinner's Foxglove
Aureolaria pedicularia var. ambigens (Gerardia pedicularia var. ambigens),
Prairie Fern-leaf False Foxglove
Orobanche ludoviciana, Louisiana Broom-rape
Utricularia cornuta, Horned Bladderwort
Plantagp cordata, Heart-leaf Plantain
Galium Tabradoricum, Bog Bedstraw
Galium palustre, Marsh Bedstraw
Symphoricarpos albus var. albus, Snowberry
Cirsium carolinianum, Carolina Thistle
Eupatorium hyssopifolium, Hyssop Thoroughwort
Heterotheca~graminifolia (Chrysopsis graminifolia), Silkgrass
Hieracium canadense, Canada Hawkweed
Hieracium longipilum, Long-bearded Hawkweed
Hymenoxys acaulis (Actinea herbacea), Lakeside Daisy
Prenanthes aspera, Rough Rattlesnake-root
Silphium laciniatum, Compass-plant
Solidago odora, Sweet Goldenrod
Verbesina occidentalis, Yellow Crownbeard
H-6
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TABLE H-3. ENDANGERED UNIONID MOLLUSCS KNOWN TO
HAVE INHABITED THE SCIOTO RIVER SYSTEM
Scientific Name
Simpsonaias ambigua
Quadrula cylindrica
Quadrula metaneura
Quadrula nodulata
Fusconaia maculata
Plethobasus cyphyus
Pleurobema clava
Pleurobema cordatum
Cyprogenia stegaria
Potamilus laevissimus
Lampsilis teres
Lampsilis orbiculata
Lampsilis ovata
Common Name
Simpson's Shell
Cob Shell
Knobbed Rock Shell
Winged Pimpleback
Long-solid
Common Bullhead
Club Shell
Ohio Pigtoe
Ohio Fan Shell
Fragile Heel-Splitter
Yellow Sand Shell
Pink Mucket Pearly Mussel
Ridged Pocketbook
H-7
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Table H-4. Rare or endangered fish species collected during the 1979-1981
sampling period and/or listed as occurring in the central
Scioto River mainstem study area by the Ohio Department of
Natural Resources, Heritage Program. (Source: Ohio EPA
1986a).
Spedtf
Lake chubsucker
Bluebreast darter
Goldeye
ODNR Status
Endangered
Threatened
Undete rained
OOHR Locations. Tear
Ctrclevllle Canal off Rd 100 (1974, 1981)
1) Scioto R at aouth of Deer Cr. (1961)
2) Scioto R near Clrclevllle (1962)
3) Scioto R. below Big Darby confluence (1963)
1) Scioto R. at Sreenlawn Ave. (1959)
2) Scioto R. dst. Big Darby Cr.
Ohio EPA collections, datts
Not collected
Not collected
KM 74.1 (1981)
Silver lanprey-
Shortnose gar
River redhorse
Endangered
Endangered
Endangered
Shorthead redhorse
Paddleflsh
Undetermined
Endangered
confluence (1962)
Scioto R at CMIIIcotht (1964)
Scioto R. dst. Chillieothe 1973
1) Scioto R. ust. Big Darby Cr. (1962)
2) Scioto R..dst. Dublin Rd. VTP dan (1979)
1) H. brevlceps - Scioto R. at
M. brevlceps - Sclo
"CMIUcothe (1964)
Scioto R. dst. Breenlawn da* (1976)
Not collected
(only below CMIUcothe, 1979)
RN 118.8 (1981)
RM 70.7 (1980
RM 78.3 (1979
RM 102.0 (1979
RN 102.0 (1981
RM 104.8 (1979
RM 134.8 (1981)
RM 138.6 (1981)
RM 138.6-70.7 (72 fish;
1979-1981)
Olentangy R. (1980)
Btg Walnut Cr. (1980,1981)
Not collected
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H-8
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APPENDIX I
SITES AND STRUCTURES IN
THE COLUMBUS AREA LISTED
ON THE NATIONAL REGISTER
OF HISTORIC PLACES
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APPENDIX I
The following sites/structures are listed on the National Register of
Historic Places.
Delaware County
Ashley, Building at 500 East High Street
(Eastlake Houses of Ashley Thematic
Resources) (11-25-80)
Building at 505 East High Street
(Eastlake Houses of Ashley Thematic
Resources) (11-25-80)
Building at 101 North Franklin Street
(Eastlake Houses of Ashley Thematic
Resources) (11-25-80)
Building at 223 West High Street
(Eastlake Houses of Ashley Thematic
Resources) (11-25-80)
Ashley vicinity, Sharp, Samuel, House
(Sharp's Run), 7436 Horseshoe Rd.
(07-29-82)
Delaware. Delaware County Courthouse.
N. Sandusky St. and Central Ave.
(5-22-73) PH0034681
Delaware Public Library, 100 N. Sandusky
St. (01-11-83)
Elliott Hall, Sturges Library, and
Merrick Hall. Ohio Wesleyan
University Campus (4-23-73) PH0094480
Monnett Hall, Ohio Wesleyan University
Campus at Elizabeth and Winter Sts.
(6-23-75).
Sandusky Street Historic District.
44 S. to 92 N. Sandusky, 47 E. to
31 W.
St. Mary's Church and Rectory, 82 E.
William St. (5-23-80)
Van Deman, Henry, House, 6 Darlington
Rd. (05-31-84)
1-1
Delaware vicinity. Greenwood Farms.
S. of Delaware off U.S. 42 (4-17-79);
79/07/23 079 0001773
Limestone Vale, 3490 Olentangy River Rd.
(10-2-78)
Ufferman Site, N. of Delaware (7-24-74)
PH0034711
Warren Tavern Complex. U.S. 36
(08/30/83)
Galena vicinity. Curtiss, Marcus, Inn
E. of Galena at 3860 Sunbury Rd.
(12-12-76)
Keeler, Diadatus. House, SE of Galena
at 4567 Red Bank Rd. (2-2-79)
80/01/10079 0006789
Spruce Run Earthworks. About 3 mi. S.
of Galena, (7-16-73) PH0034703
Harlem vicinity. Cook, John, Farm, E.
of Harlem at Miller Paul Rd. and
Gorsuch Rd. (4-11-77)
Olive Green vicinity. Chambers Road
Covered Bridge, 1.5 mi. NE of Olive
Green (11-21-74) PH0085049
Sunbury Tavern (Hopkins House), NW
corner OH 37 and Galena Rd. (2-24-75)
Sunbury Township Hall, Town Sq.
(2-20-75)
Sunbury vicinity, Center Inn, SE of
Sunbury on OH 37 (01/11/83)
Westerville vicinity, Sharp, Stephen,
House, N. of Westerville on Africa Rd.
(09/30/82)
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Winter, and 9 E. to 17 W. William
(12-17-82)
Worthington vicinity. Highbank Park
Works. E. bank of Olentangy River
(2-15-74) PH0112895
Fairfield County
Amanda, Barr House, 350 W. Main St.
(11-26-80)
Amanda vicinity. Allen, Lyman, House
and Barn, NW of Amanda on OH 188
(11-18-76)
Baltimore vicinity. Bright, John,
Covered Bridge, 2.5 mi. SW of
Baltimore over Poplar Creek (5-28-75)
Miller Farm, S of Baltimore on
Pleasantville Rd. (5-22-75)
Musser, Henry, House, SE of Baltimore at
7079 Millersport Rd. (5-5-78)
Pugh-Kittle House, 2140 Bickel Church
Rd. (06-16-83)
Canal Winchester. Loucks Covered
Bridge, SE of Canal Winchester on SR
207 (Diley Rd.) (10-8-76)
Carroll vicinity. Ety Enclosure, NE of
Carroll (7-12-74) PH0034801
Ety Habitation Site, NE of Carroll
(7_24-74) PH0034819
Carroll vicinity. John Bright, No. 1
Iron Bridge, 2 mi. (3.2 km) NE of
Carroll on Havensport Rd. (9-20-78)
Lancaster. Bush, Samuel, House, 1934
Cold Spring Dr. (10-1-74) PH0034762
Lancaster Historic District, Roughly
bounded by 5th Ave., Penn Central
Lancaster West Main Street Historic
District, W. Main St. from Columbus to
Broad St. (2-2-79); 80/01/10079
0006790
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Medill, William, House, 319 N. High St.
(3-30-78)
Sherman, John, Birthplace, 137 E. Main
St. (10-15-66) PH0034845 NHL.
Square 13 Historic District, Roughly I
area along Broad and High Sts. between*
Mulberry and Chestnut Sts. (7-24-72)
PH0034851 HABS;G
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St. Peter's Evangelical Lutheran Church,
Broad and Mulberry Sts. (4-16-79); —
79/07/23 079 0001775 1
Lancaster, Tallmadge-Mithoff House, 720
Lincoln Ave. (5-6-76)
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Lancaster vicinity. Chestnut Ridge Farm,
3375 Cincinnati-Zanesville Rd., SW.
(7-24-72) PH0034771 •
Concord Hall, 1445 Cincinnati-Zanesville
Rd., SW. (U.S. 22) (10-25-72)
PH0034789
Reber, Valentine, House, W. of Lancaster
at 8325 Lancaster-Circleville Rd.
(OH 188) (7-30-75)
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Willow Lane Farm (Nathaniel Wilson —
House), SW of Lancaster on U.S. 22 •
(10-26-72) PH0034878 •
Lithopolis vicinity. Old Maid's Orchard*
Mound, E. of Lithopolis (7-15-74) •
PH0034843
Lockville. Lockville Canal Locks, Off •
Pickerington-Lockville Rd. (9-10-74) •
PH0085006
Pickerington vicinity, Dovel, J.H., •
Farm, 660 N. Hill Rd. (03-15-82) m
Hizey Covered Bridge, E. of Pickerington
on SR 235 (10-8-76)
Stemen Road Covered Bridge, NE of »
Pickerington over Sycamore Creek, •
(4-20-79); 79/07/23 079 0001776 *
RR tracks, OH 33 and Tennant St.
(08-11-83)
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Rushville, Rushville Historic District,
Bremen Ave., Main and Market Sts.
(11-24-80)
Rushville vicinity. Winegardner
Village (7-30-74) PH0034886
Rock Mill. Rock Mill Covered Bridge,
SR 41 (4-26-76)
Royalton. Royalton House, Amanda
Northern Rd. (7-30-75)
Sugar Grove vicinity. Crawfis
Institute, Crawfis and Old Sugar Grove
Rds. (11-29-79); 80/01/10079 0006402
West Rushville, Ijams, Joseph, House,
Broad and Main Sts. (06/16/83)
Franklin County
Bexley, Duncan, Robert P., House, 333 N.
Parkview Ave. (08-23-84)
Jeffrey, Malcomn, House 358 N. Parkview
(05-08-83)
Canal Winchester, Canal Winchester
Methodist Church, S. Columbus and High
Sts. (03-15-82)
Canal Winchester vicinity. Bergstresser
Covered Bridge, W. of OH 674 over
Walnut Creek (5-3-74) PH0070181
Central College Multiple Resource Area.
This area includes: Westerville
vicinity, Central College Presbyterian
Church, Sunbury Rd.; Fairchild
Building.
Central College vicinity. Squire's Glen
Farm, 6770 Sunbury Rd. (8-13-74)
PH0070432
Columbus, American Insurance Union
Citadel, 50 W. Broad St. (3-21-75)
Camp Chase Site, 2900 Sullivant Ave.
(4-11-73) PH0112909
Broad Street United Methodist Church,
501 E. Broad St. (11-26-80)
Columbia Building, 161-167 N. High St.,
(08-12-83)
Capital University Historic District,
E. Main St. and College Ave.
(12-17-82)
Columbus Country Club Mound, 4831 E.
Broad St., (2-15-74) PH0070211
Columbus Near East Side District,
Roughly bounded by Parsons Ave., Broad
and Main Sts., and the railroad
tracks (5-19-78)
Columbus Savings and Trust Building
(Atlat Building), 8 E. Long St.
(9-15-77)
Columbus Transfer Company Warehouse,
55 Nationwide Blvd. (02-24-83)
Drake, Elam, House, 2738 Ole Country
Lane (4-6-78)
East Town Street Historic District,
Roughly bounded by Grant and Franklin
Aves., Lester Dr. and E. Rich St.
(7-30-76)
Felton School, Leonard Ave. and N.
Monroe St. (05-31-84)
Fort Hayes, Cleveland Ave. and 1-71
(1-26-70) PH0070238
Franklin Park Conservatory, 1547 E.
Broad St. (1-18-74) PH0070246
Franklinton Post Office (David Deardurf
House), 72 S. Gift St. (3-20-73)
PH0070254
German Village, Roughly bounded by
Livingston Ave., Pear Alley, Nursery
Lane, Blackberry Alley, and Lathrop
St. (12-30-74) PH0044148
Great Southern Hotel and Theatre,
S. High and E. Main Sts. (12-02-82)
Hamilton Park Historic District, Broad
and Long Sts. (07-28-83)
1-3
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Hanna House, 1021 E. Broad St.
(4_19_79); 79/07/23 079 0001778
Harrison, Gen. William Henry,
Headquarters (Jacob Oberdier House),
570 W. Broad St. (12-15-72) PH0070271
Hayes and Or ton Halls, Ohio State
University, The Oval (7-16-70)
Higgins, H.A., Building (Flatiron
Building), 129 E. Naghten St.
(8-27-79); 79-11-30 079 0005031
Holy Cross Church, Rectory and School,
212 S. 5th St. (4-26-79) 79/07/23 079
001779
Huntington, Franz, House, 81 N. Drexel
Ave. (5-29-80)
Indianola Junior High School, 420 E.
19th Ave. (6-30-80)
Jaeger Machine Company Office Building,
550 W. Spring St. (06-16-83)
Jefferson Avenue Historic District,
Roughly bounded by 1-71, E. Broad,
llth, and Long Sts. (12-02-82)
Jones, W.H., Mansion, 731 E. Broad St.
(10-2-78)
Krumm House, 975-979 S. High St.
(09-30-82)
Long and Third Commercial Building,
103-113 E. Long St. (07-01-82)
Near Northside Historic District, Off OH
315 (6-4-80)
North Market Historic District, Roughly
bounded by W. Goodale, Park, High,
Front, and Vine Sts. (12-30-82)
Ohio Asylum for the Blind, 240 Parsons
Ave. (7-26-73) PH0070351
Ohio National Bank, 167 S. High St.
(11-26-80)
Ohio Stadium, 404 W. 17th Ave. (3-22-74)
PH0070360
1-4
Ohio State Arsenal, 139 W. Main St.
(7-18-74) PH0070378
Ohio Statehouse, SE corner of High and
Broad Sts. (7-31-72) PH0070386 G.
Ogers, Isaiah Saiah Rogers.
Ohio Theatre, 39 E. State St. (4-11-73)
PH0070394 NHL; G.
Old Governor's Mansion (Ohio Archives
Building, Charles H. Lindenberg
House), 1234 E. Broad St. (6-5-72)
PH0070408
Old Ohio Union, 154 W. 12th Ave.
(4-20-79); 79/07/23 079 0001780
Old Port Columbus Airport Control Tower,
420 E. 5th Ave. (7-26-79); 79-11-13
079 0004392
Orton Memorial Laboratory, 1445 Summit
St. (11-25-83)
Pierce, Elijah, Properties, 435 E. Long
St. and 142-44 N. Everett Alley
(08-03-83)
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Pythian Temple and James Pythian
Theater, 861-867 Mt. Vernon Ave. m
(11-25-83) •
Rankin Building, 22 W. Gay St.
(03-10-82)
Rickenbacker, Capt. Edward V., House,
1334 E. Livingston Ave. (5-11-76) NHL.
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Schlee-Kemmler Building, 328 S. High St
(12-02-82)
Second Presbyterian Church, 132 S. ThirdB
St. (01-11-83) "
Seneca Hotel, 361 E. Broad St.
(12-29-83)
Sessions Village, Both sides of Sessions,
Dr. (2/20/75)
Smith, Benjamin, House, 181 E. Broad
St. (6/4/73) PH0070424
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South High Street Commercial Grouping,
Bounded by Pearl, Mound, Main, and
High Sts. (12/29/83)
Sullivant, Lucas, Building, 714 W. Gay
St. (3/20/73) PH0070441
Thurber, James, House, 77 Jefferson Ave.
(11/8/79); 80/01/10079 0006403
Toledo and Ohio Central Railroad
Station, 379 W. Broad St. (6/18/73)
PH0070475 HAER; G.
Trinity Episcopal Church, 125 E. Broad
St. (11/13/76)
U.S. Post Office and Courthouse (Old,
Old Post Office), 121 E. State St.
(4/11/73)
Valley Dale Ballroom, 1590 Sunbury Rd.
(12/17/82)
Welsh Presbyterian Church, 315 E. Long
St. (11/24/80)
Wyandotte Building, 21 W. Broad St.
(2/23/72) PH0070491 HABS
York Lodge No. 583, 1276 N. High St.
(07/19/84)
Columbus Vicinity
Agler-la Follette House, 2621 Sunbury
Rd. (12/14/78)
Davis, Samuel, House, 4264 Dublin Rd.
(2/15/74) PH0070220
Hartman Stock Farm Historic District,
S. of Columbus on U.S. 23 (10/9/74)
PH084999
Jackson Fort (12/10/74) PH0085251
McDannald Homestead, NE of Columbus at
5847 Sunbury Rd. (2/17/78)
Noble, Jonathan, House, 5030 Westerville
Rd. (SR 3) (12/3/75)
Dublin vicinity. Davis, Anson, House,
4900 Hayden Run Rd. (7/7/75)
1-5
Holder-Wright Works (2/15/74) PH0070319
Sells, Benjamin, House, S. of Dublin at
4586 Hayden Run Rd. (7/30/75)
Gahanna, Shepard Street School (Gahanna
Nursing Home), 106 Short St.
(11/29/79); 80/01/10079 0006404
Grove City, Gantz Homestead, 2233 Gantz
Rd. (6/20/79); (10/23/79) 079 0002507
Groveport, Groveport Log Houses, Wirt
Rd. (5/6/76)
Groveport Town Hall Historic Group, 628,
632 Main and Main and Front Sts.
(7/31/78)
Billiard vicinity. Wesley Chapel, SE of
Billiard at 3299 Dublin Rd. (2/27/79);
79/07/13 079 0000620
Lockbourne vicinity, Herr, Christian S.,
Bouse, N. of Lockbourne at 1451
Rathmell Rd. (03/05/82)
Marble Cliff, Miller, J.F., House, 1600
Roxbury Rd. (05/31/84)
Riverlea, Russell, Mark, House 5805 N.
High St. (12/12/76)
Sunbury Rd.; Presbyterian Parsonage,
6972 Sunbury Rd.; Washburn, Rev.
Ebenezer, Bouse, 7121 Sunbury Rd.
(11/25/80)
Washington Township. Washington
Township Multiple Resource Area. This
area includes various properties at
various locations. Details available
upon request. (4/11/79); 79/07/16 079
0001090
Westerville, Alkire House, 269 N. State
St. (3/30/78)
Hanby, Benjamin, House, 160 W. Main St.
(11/10/70) PH0094501
Hart, Gideon, House, 7328 Hempstead Rd.
(8/14/73) PH0070289
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Otterbein Mausoleum, W. Walnut St.
(11/29/79); 80/01/10079 0006405
Towers Hall, Otterbein College, Main and
Grove Sts., Otterbein College campus
(3/4/71) PH0070459
Westerville High School, Vine Street
School, 44 N. Vine St. (5/29/75)
Westerville vicinity. Everal, John W.,
Farm Buildings, 7610 Cleveland Ave.
(9/18/75)
Osborn, Charles S., 5785 Cooper Rd.
(3/28/77)
Worthington, Johnson, Orange, House,
956 High St. (4/3/73) PH0070335
New England Lodge, 634 N. High St.
(3/20/73) PH0070343
Snow, John, House, 41 W. New England
Ave. (7/26/73) PH0071251
Worthington Manufacturing Company
Boardinghouse, 25 Fox Lane (6/19/73)
PH0112917
Worthington Multiple Resource Area.
This area includes: Adams, Demas,
House, 721 High St.; Bishop-Noble
House, 48 W. South St.; Brown, Sidney,
House, 12 E. Strafford Ave.; Fay,
Cyrus, House, 64 W. Granville Rd.;
Gardner House, 80 W. Granville Rd.;
Johnson, Orange, House, 956 High St.
(previously listed in the National
Register 4-3-73); Kilbourne House,
679-681 High St.; Ladd-Mattoon House,
73 E. North St.; New England Lodge,
634 High St. (previously listed in the
National Register 3-20-73); Old
Worthington Inn, New England and High
Sts.; President's House, 38 Short St.;
Ripley House, 623 High St.; St. John's
Episcopal Church, 700 High St.; Scott,
Travis, House, 72 E. Granville Rd.;
Sharon Township Town Hall, Granville
Rd. and Hartford St.; Skeele, Capt.
J.S., House, 700 Hartford St.; Snow,
John, House, 41 W. New England Ave.
(previously listed in the National
Licking County
Brownsville vicinity. Flint Ridge
(11/10/70) PH0070904
Croton vicinity. Belle Hall Covered
Bridge, E. of Croton on Dutch Cross
Rd. (10/22/76)
Granville, Avery-Hunter House, 221 E.
Broadway (12/27/79)
Buxton Inn, 313 E. Broadway (12/26/72)
PH0070874
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Register 7-26-73); Topping, J.R.,
House, 92 E. Granville Rd.; Park,
Jonathan, House, 91 E. Granville Rd.; I
Wilcox, Hiram, House 196 E. Granville §
Rd.; Worthington Historical Society
Museum, 50 W. New England Ave.; ^
Worthington Manufacturing Company I
Boarding House, 25 Fox Lane ™
(previously listed in the National
Register 6-19-73); Worthington United
Presbyterian Church, High St. and W.
Granville Rd.; Worthington Village
Green, Village Green; Wright, Horace, _
House, 137 E. Granville Rd.; Wright, •
Potter, House, 174 E. New England Ave. •
(4/17/80)
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Granville Multiple Resource Area
(Partial Inventory). This area
includes: Granville, Granville
Historic District, OH 37; Bancroft,
A.A., House, N. Pearl St. and
Washington Dr.; Carpenter, Wallace W., _
House (The Castle) 323 Summit St.; •
Dustin Cabin, 597 N. Pearl St.; RogersM
House, 304 N. Pearl St.; Rose, Capt.
Levi, House 631 N. Pearl St.
(11/28/80)
St. Lukes Episcopal Church, 111 E.
Broadway St. (4/26/76)
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Folly), 3758 Lancaster Rd., SW m
(03/29/83) •
McClune's Villa, 537 Jones Rd.
(04/22/82)
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Stanbery, Edwin, Office, 1 mi (1.6 km)
E. of Granville (11/30/78)
Heath, Ohio Canal Groundbreaking Site,
OH 79 (5/24/73) PH0070963
Johnstown, Monroe Township Hall-Opera
House, 1 S. Main St. (7/6/81)
Johnstown vicinity. Lynnwood Farm, S.
of Johnstown at 4986 Caswell Rd.
(6/22/79); (10/23/79) 079 0002509
Newark. Chapel Hill Cemetery Buildings,
Cedar St., Chapel Hill Cemetery
(4/13/77)
Courthouse Center, 35-37 S. Park PI. and
jet. of S. Park and S. 2nd St.
(11/29/79); 80/01/10079 0006411
Home Building Association Bank, 6 W.
Main St. (7/2/73) PH0070912
Hull Place, 686 tf. Main St. (12/21/79)
Licking County Courthouse, Courthouse
Sq. (3/20/73) PH0070921
McNamar-McLure-Miller, Residence, 124 W.
Main St. (06/17/82)
Newark Earthworks, Mound Builders State
Memorial (10/15/66) PH0070955 NHL.
Oakwood, 64-70 Penney Ave. (5/29/80)
Pennsylvania Railway Station, 25 E.
Walnut St. (11/29/79); 80/01/10079
0006412
Rhoads, Peter F., House, 74 Granville
St. (11/28/80)
Sherwood-Davidson and Buckingham Houses,
W. Main and 6th Sts. (11/10/77)
Shield's Block, 23-29 S. Park PI.
(11/29/78)
Upham-Wright House, 342 Granville St.
(6/22/79); (10/23/79) 079 0002510
West Side Planning Mill, 197 Maholm St.
(01/21/83)
1-7
Williams, Elias, House (Bolton House),
565 Granville St. (4/16/79); 79/07/23
079 0001786
Newark vicinity. Upland Farm, N. of
Newark off OH 657, (12/1/78)
Pataskala, Bethel Baptist Church
(Pataskala MRA), Vine and Cedar Sts.
(09/22/83)
Casterton House (Pataskata MRA), 105
Broadway (09/22/83)
Elliot House (Pataskala MRA), 301 S.
Main St. (11/14/83)
Kauber, Warren F., Funeral Home
(Pataskala MRA), 289 S. Main St.
(09/22/83)
Mead House (Wind Flower House)
(Pataskala MRA), 245 S. Main St.
(09/22/83)
Pataskala Banking Company (Pataskala
MRA), 354 S. Main St. (09/22/83)
Pataskala Elementary School (Pataskala
MRA), 396 S. High St. (09/22/83)
Pataskala Jail (Pataskala MRA), Main St.
(09/22/83)
Pataskala Presbyterian Church (Pataskala
MRA), Atkinson and Main Sts.
(11/14/83)
Pataskala Town Hall (Pataskala MRA),
Main St. (09/22/83)
Pataskala United Methodist Church
(Pataskala MRA), 458 S. Main St.
(09/22/83)
Madison County
Lafayette. Red Brick Tavern, 1700
Cumberland Rd. (9/5/75)
London. Madison County Courthouse,
Public Sq. (3/14/73) PH0094552
Swetland House, 147 E. High St.
(01/11/83)
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Mount Sterling. Mount Sterling Historic
District, Both sides of London St.
(10/1/74) PH0060801
Plain City vicinity. Gary Village Site,
SE of Plain City (5/13/75)
Somerford vicinity. Wilson, Valentine,
House, About 1 mi. N. or Somerford off
1-70 (5/22/73) PH0060828
Pickavay County
Ashville, Ashville Depot, Madison and
Cromley Sts. (2/25/80)
Circleville. Anderson, William
Marshall, House, 131 W. Union St.
(11/29/79); 80/01/10079 0006419
Circleville Historic District, Main and
Court Sts. (5/16/78)
Memorial Hall, 165 E. Main St.
(11/21/80)
Morris House, 149 W. Union St. (8/3/79);
79-11-13 079 0004400
Circleville vicinity, Horsey-Barthelmas
Farm, W. of Circleville on OH 104
(7-24-80)
Lawndale Farm Complex, 26476 Gay
Dreisbach Rd. (04/19/84)
Mount Oval (Tolbert House), Off U.S. 23
(7/25/74) PH0071293
Peters, Stevenson, House, OH 188
(02/09/84)
Redlands, 1960 N. Court St. (05/14/82)
Kingston vicinity. Bellevue, N. of
Kingston on OH 159 (3/17/76)
Marcy vicinity. Fridley-Oman Farm,
W. of Marcy in Slate Run Metropolitan
Park (12/6/75)
South Bloomfield vicinity, Renick Farm,
N. of Bloomfield on U.S. 23 (03/05/82)
Williamsport vicinity. Bazore Mill,
S. of Williamsport on OH 138 at Deer
Creek (12/19/78)
Williamsport vicinity. Shack, The, NW
of Williamsport (5/23/74) PH0071307
The following properties have been
determined to be eligible for
inclusion in the National Register.
Fairfield County
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Lancaster, U.S. Post Office—Lancaster I
(10/28/83) fl
Richland, R.F., Baker Bridge, Thornville •
Rd. and Little Rush Creek; 78/11/13 •
078 0055084 "
Franklin County
Columbus, Barber Shop, 82-86 E. Town
St. (1204.3)
Beggs Building, 21 E. State St.
Bldg. at 736-40 East Long Street
(02/17/84)
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Central National Bank Building, 152-166
S. High St. (1204.3) •
Hartman Theater Building, 73-87 E. State
St. (1204.3)
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LaSalle Wine Store, 242-244 S. High St.
(1204.3)
Owen, Jim, Real Estate, 232 S. High St.
(1204.3)
Trailways, 246-254 S. High St. (1204.3) I
1000-02 S. High Street (63.3)
17-19 E. Stewart Avenue (63.3) (
21-33 E. Stewart Avenue (63.3)
99 S. High Street (63.3)
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Licking County
Health. Digiondomenico Site (Ohio LIC
343-0.00).; 78/11/15 078 0050632
Pickavay County
Darby township, Orient Bridge, OH 762
over Big Darby Creek (63.3)
The following sites/structures are
pending inclusion to the National
Register.
Franklin County
Broad Street Apartments, East Broad
Street MRA, 880—886 E. Broad St.,
86003404 11/04/86
Broad Street Christian Church, East
Broad Street MRA, 1051 E. Broad St.,
86003448, 11/04/86
Cambridge Arms, East Broad Street MRA,
926 E. Broad St., 86003412, 11/04/86
Central Assurance Company, East Broad
Street MRA, 741 E. Broad St. 86003421,
11/04/86
East Broad Street Commercial Building,
East Broad Street MRA, 747, 749, 751
E. Broad St., 86003424, 11/04/86
East Broad Street Historic District,
East Broad Street MRA, Along E. Broad
St. between Monypenny and Ohio Aves.
86003393, 11/04/86
East Broad Street Presbyterian Church,
East Broad Street MRA, 760 E. Broad
St., 86003397, 11/04/86
Garfield—Broad Apartments, East Broad
Street MRA, 775 E. Broad St.,
86003427, 11/04/86
Heyne—Zimmerman House, East Broad
Street MRA, 973 E. Broad St.,
86003450, 11/04/86
Hickok, Frank, House, East Broad Street
MRA, 955 & 957 E. Broad St., 86003444,
11/04/86
1-9
House at 753 East Broad Street, East
Broad Street MRA,, 753 E. Broad
Street, 86003425, 11/04/86
Jacobs, Felix A., House, 1421 Hamlet
St., 86003434, 11/04/86
Johnson—Campbell House, East Broad
Street MRA, 1203 E. Broad St.,
86003414, 11/04/86
Joseph—Cherrington House, East Broad
Street MRA, 785 E. Broad St.,
86003429, 11/04/86
Kauffman, Linus E., House, East Broad
Street MRA, 906 E. Broad St.,
86003410, 11/04/86
Kaufman, Frank J., House, East Broad
Street MRA, 1231 E. Broad St.,
86003420, 11/04/86
Levy, Soloman, House, East Broad Street
MRA, 929 E. Broad St., 86003427,
11/04/86
Lovejoy, Carrie, House, East Broad
Street MRA, 807 E. Broad St.,
86003435, 11/04/86
Morris, C.F., House, East Broad Street
MRA, 875 E. Broad St., 86003398,
11/04/86
Frentiss, Frank, House, East Broad
Street MRA, 706 E. Broad St.,
86003396, 11/04/86
Prentiss—Tulford House, East Broad
Street MRA, 1074 E. Broad St.,
8603413, 11/04/86
Saint Paul's Episcopal Church, East
Broad Street MRA, 787 E. Broad St.,
86003430, 11/04/86
Schueller, Erwin W., House, East Broad
Street MRA, 904 E. Broad St.,
86003406, 11/04/86
Scofield—Saner House, East Broad Street
MRA, 1031 E. Broad St., 86003447,
11/04/86
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Sharp—Page House, East Broad Street
MRA, 935 E. Broad St.
86003445
86003449
ARCHAEOLOGICAL SITES
Delaware County
Powell vicinity. Highbanks Metropolitan
Park Mounds I and II, E. of Powell on
U.S. 23 (3/19/75)
Fairfield County
Canal Winchester vicinity. Schaer,
Theodore B., Mound, SE of Canal
Winchester (6/20/75)
Carroll vicinity, Coon Hunters Mound
(5/2/74) PH0034797
Pinkerington vicinity. Fortner Mounds
I, II. NE of Pinkerington (7/12/74)
PH0034827
Tarlton vicinity. Tarlton Cross Mound,
N. of Tarlton (11/10/70) PH0034860
Franklin County
Columbus. Campbell Mound (11/10/70)
PH0094498
COE Mound, W. of High St. (7/18/74)
PH0070203
Columbus vicinity. Hartley Mound, N. of
Columbus (7/15/74) PH0070297
Galloway vicinity. Galbreath, John
Mound, W. of Galloway (7/15/74)
PH0070262
Georgesville vicinity. Cannon, Tom,
Mound (5/2/74) PH0070190
Worthington vicinity. Jeffers, H.P.,
Mound (5/2/74) PH0070327
Licking County
Granville vicinity. Alligator Effigy
Mound (11/5/71) PH0070891
Homer. Dixon Mound (Williams Mound)
(6/4/73) PH0070882
Reynoldsburg vicinity. ETNA Township
Mounds I and II, E. of Reynoldsburg
off 1-70 (9/5/75)
Utica vicinity. McDaniel Mound (5/2/74)
PH0070939
Melick Mound, S. of North Fork of
Licking River (3/27/74) PH0070947
Madison County
West Jefferson vicinity. Skunk Hill
Mounds (7/30/74) PH0060810
Pickavay County
Circleville vicinity. Arledge Mounds I
and II (7/30/74) PH0071285
Luthor List Mound (10/16/74) PH0034291
Fox vicinity. Clemmons, W.C., Mound
(5/2/74) PH0071315
Tarlton vicinity. Horn Mound (8/7/74)
PH0034304
Williamsport vicinity. Tick Ridge Mound
District, NW of Williamsport (6/11/75)
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APPENDIX J
ARCHAEOLOGIC BACKGROUND
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APPENDIX J
ARCHAEOLOGIC BACKGROUND
The earliest evidence of human culture within the Scioto Drainage system
is evidenced by the Fluted Point Complex of the Palaeo-Indian Tradition, which
has been dated to between 18,000 and 10,000 years B.C. This component, the
Fluted Point Complex, is represented primarily by the surface recovery of
isolated Fluted Points (projectile points) and other characteristic artifacts
of this manifestation.
The Fluted Point Complex is followed by the Piano Complex of the Palaeo-
Indian Tradition, dating between 10,000 and 6,000 years B.C. The Piano
Complex is documented in the Scioto Valley by a series of isolated surface
finds of characteristic projectile point types including Lanceolate Points,
Sawmill Stemmed Lanceolate Points, and Stringtown Spurred-Stemmed Lanceolate
Points.
The known distribution of Piano Complex workshop sites centers in
Coshocton County in proximity to the outcrops of Upper Mercer Flint with a
secondary center in Licking County adjacent to the heavily utilized Flint
Ridge Flint. These raw materials were used in the manufacture of the vast
majority of Lanceolate-style projectile points. The distribution of excavated
sites and surface finds in this region would be along major stream valleys.
The Archaic Developmental Stage spans the time interval from ca. 8,000 to
1,500 years B.C. In part, the Piano Complex and the earliest manifestations
of the Archaic stage overlap in time.
The Archaic Development Stage is evidenced by two cultural traditions
throughout the Scioto Drainage system: the Appalachian Archaic Tradition
(8,000 to 3,500 years B.C.) and the Laurentian Archaic Tradition (3,500 to
1,500 years B.C.).
The Kirk Phase of the Appalachian Archaic Tradition has been dated to
between 8,000 and 7,000 years B.C., while the St. Albans Phase dates to
between 7,000 and 6,100 years B.C. The majority of sites are situated within
the low terraces of the major stream valleys—in environmental zones that have
been reconstructed as bottomland hardwood forests.
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The distribution of Kirk and St. Albans Phase components is rather well
known for the Scioto Drainage south of Circleville. Stray surface finds of
Kirk Corner-Notched and St. Albans Bifurcated-Base projectile points were
recovered along both the east and west banks of the Scioto River in southern
Franklin County. However, it was not possible to define either clusters of
artifact occurrence or to define sites on the basis of this analysis. The
only evidence for Archaic Stage (6,000 and 3,500 years B.C.) occupation of the
Scioto Drainage has come from the surface recovery of several well-defined
projectile point types, either as isolated surface occurrences or from
occurrences in multicomponent surface manifestations.
The Laurentian Tradition represents the most recent of the Archaic
Development Stage manifestations within Ohio. The various components of the
tradition have been radiocarbon dated to between ca. 3,500 years B.C. and
prior to 1,500 years B.C. In this region, one phase of the tradition has been
defined: the Dunlap Phase of the Laurentian Tradition within the central and
lower Scioto Valley. Sites occur as both open sites and within rock shelters
in the eastern portion of Ohio. The majority of open sites are situated in
close proximity to the then-contemporary shorelines of water sources (lakes,
bogs, swamps, and streams).
The Glacial Kame Manifestation represents a poorly understood series of
archaeological remains that are contemporaneous with the terminal portion of
the Laurentian Tradition. The manifestation is known primarily from the
discovery of human burials that occur deep within shaft graves excavated into
glacial kames, usually elevated over adjacent stream valleys. Sites of the
Glacial Kame Manifestation do occur in both Pickaway and Franklin Counties.
The Scioto Tradition spans the time interval from 1,500 years B.C. to ca.
900 years A.D. Three phases of the Scioto Tradition have been defined. The
three major manifestations include the following:
a. Adena Phase (Early Woodlands), dating from 1,500 years B.C. to 1
A.D./B.C.
This phase represents the earliest manifestation of the Scioto
Tradition within the Scioto Drainage. The majority of manifestations
have been dated to between 1,500 years B.C. and 1 A.D./B.C., although
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components predating 1,500 years B.C. are known from both the Hocking
River and Ohio River Valleys. Only four Adena Phase burial mounds
are known from Franklin and Pickaway Counties.
The Adena Phase mortuary ceremonial manifestation is evidenced by one
site occurring within a 10-kilometer radius of the Southerly WWTP.
Typical burial mounds of the Adena Phase represent small structures
covering less than 20 inhumations located on high terraces and/or
bluffs overlooking major stream valleys. The settlement pattern of
the Adena Phase, known for limited information, consists of small
villages or hamlets (2 to 10 structures) scattered along the low
terraces and flood plain of the stream valleys. One large habitation
site—the Dominion Land Company Site in Franklin County—has been
reported.
b. Hopewellian Phase (Middle Woodland), dating from 150 years B.C. to
650 years A.D.
This phase of the Scioto Tradition has been dated to between 150 B.C.
and 650 A.D. The greatest concentration of sites occurs in the
Scioto River Valley between Circleville and Portsmouth. The concen-
tration of Hopewellian earthworks occurs in the Scioto Valley and its
tributaries south of Columbus.
Within the central and lower Scioto Valley, Hopewellian hamlets
appear to be composed of two to four structures (houses) situated on
rises of the flood plain and first terrace of the Scioto River and
the major tributary stream.
Four Hopewellian Phase sites are known to be in the vicinity of the
Southerly WWTP project area.
c. Chesser Phase, Peters Phase, Cole Complex (Late Woodland),.dating
from 650 to between 900 and 1,000 years A.D,
The subsequent portion of the Scioto Tradition consists of a series
of regionally defined phases: the Peters Phase in the Hocking
Valley, the Chesser Phase in the lower Scioto Valley, the Cole
Complex in the upper Scioto Valley, and the Licklighter Phase in the
Miami Valley. These various Late Woodland phases occupy a time
interval that has been radiocarbon dated to between 650 and 950 to
1,000 years A.D.
The Cole Phase (also known as Cole Complex) has been defined by Baby,
Potter, and their co-workers for the upper portion of the Scioto
Valley (Circleville to Columbus) and for the Darby Creek, Upper
Scioto, and Olentangy Drainages.
The terminal portion of the pre-European culture history of the
Scioto Drainage is dominated by the Fort Ancient or Mississippian
Tradition.
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Fort Ancient Tradition settlement patterns consist of large nucleated
villages, frequently oriented around vacant plazas or areas con-
taining platform or "temple" mounds and frequently defined by
palisades. Villages are most frequently located in close proximity
to major streams and on rises within the flood plain, or on first
terraces of the stream valleys; frequently in close proximity to the
richest of the available soils.
A total of seven Late Woodland Mississippian manifestations are known
to occur in the vicinity of the Columbus Southerly project area.
Nearly all adjacent manifestations are known only from the results of
the phase II survey.
The terminal portion of the prehistoric sequence within the Scioto
Valley—the time interval from 1650 to 1680 until Anglo-European
settlement during the 1780s and 1790s—is poorly known from both the
archaeological and historical literature. Only one site has been
excavated from this time interval—the Morrison Site from the Scioto
Valley south of Chillicothe.
In summary, the Scioto Drainage system has been used by a succession
of prehistoric cultures and prehistoric populations for over 18,000
years. Many of these cultural manifestations are well represented
within the region.
A phase I and phase II survey of the Southerly WVTP in 1985 revealed
four prehistoric sites.
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APPENDIX K
POPULATION PROJECTIONS AND METHODS
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APPENDIX K
POPULATION PROJECTIONS AND METHODS
Introduction
This appendix presents past population trends of the overall planning
area as well as the proposed interceptor areas. The overall service area
covers most of Franklin County, including all of the City of Columbus as well
as small portions of Delaware, Fairfield, and Licking Counties. This review
outlines baseline data used in evaluating population projections and for
estimating the relative attractiveness for development of various communities
within the planning area.
Most of the available population projections have not been prepared for
small areas and the detailed information required for accurate small area
projections is not available. The 1980 census provides the baseline for the
trend analysis used to prepare all of the regional population projections.
Because growth between 1970 and 1980 was less than expected and the growth
between 1980 and 1985 was greater than expected, the Ohio Department of
Economic Development, which prepares the State population estimates at the
Ohio Data Users Center (ODUC), has revised its official estimates three times
since the 1980 U.S. Census. The most recent estimate was published and
verified in September of 1985. Both the Mid-Ohio Regional Planning Commission
(MORPC) and Ohio Environmental Protection Agency (OEPA) prepare population
estimates for small areas; that is counties, cities, and unincorporated areas.
These two agencies have not revised their population estimates to reflect the
most recent ODUC projections. Therefore, these small area projections do not
reflect the most recent State-approved projections. The Revised Facility Plan
Update (RFPU) considers these revisions, but does not reflect the region's
most recent growth trends.
Revised Facilities Plan Update Projections
Population levels were forecast for the year 2015 in the RFPU. Besides
the year 2015 population, used for planning purposes, the population in 1988
also was evaluated by this RFPU because the Clean Water Act Amendments mandate
compliance by all wastewater treatment facilities with NPDES permit limits by
K-l
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July 1, 1988. The following sources of population data and existing projec-
tions were reviewed prior to development of RFPU projections:
o Environmental Impact Statement (EIS) for Wastewater Treatment
Facilities for the Columbus Metropolitan Area (US EPA 1979);
o Design Finalization Overview Team Report (AWARE 1984);
o Facilities Plan Update Report (Malcolm Pirnie 1984);
o Growth Potential Report (City of Columbus 1984);
o Ohio Department of Development, Data Users Center, State and County
Projections (June 1982);
o Ohio Department of Development, Data Users Center, Draft Final
Population Projections (August 1985);
o Traffic Zone Projections - 1980 and 2010 (Mid-Ohio Regional Planning
Commission 1983);
o Franklin County projections developed by the Design Parameters Team as
a check against other projections;
o Miscellaneous Facilities Plan and Facilities Plan Segment documents
pertaining to sewer service areas;
o Ohio Environmental Protection Agency, Office of the Planning
Coordinator, Water Quality Management Plan Projections (1977, 1982).
As the preceding list indicates, numerous sources using various methodologies
were used to make population projections in the RFPU and the Consolidated
Environmental Information Document (BID). For the purpose of this EIS, the
population projections prepared by the Ohio Data Users Center (a division of
the Ohio Department of Development) and the OEPA were reviewed and adjusted to
reflect the overall service area for 1988, 2000, and 2008.
Ohio Data Users Center Projections
The ODUC prepares the official population projections for the State of
Ohio. ODUC bases its recent projections on the 1980 U.S. Census, and historic
trends for migration, births, and deaths. The projections reviewed in this
EIS were revised in September 1985. These projections were prepared on the
county and state level, for the years 1980 through 2010. A preliminary
accuracy check recently was conducted by ODUC for their Franklin County
K-2
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forecasts. During this check, the population estimates were well within the
accepted statistical confidence level with an error rate of less than 2
percent.
Table K-l shows ODUC's population projections for the State of Ohio and
the four counties in the service area for 1980 through 2010. This table shows
that the State of Ohio will decrease over the 30-year period while the
population in Franklin County as well as the other counties in the service
area will increase.
ODUC is responsible for certifying population projections prepared within
the State. In 1982, after several public hearings, ODUC certified OEPA's
Planning and Engineering Data Management System for Ohio (PEMSO) population
projections. The OEPA prepared its projections for selected service areas on
the township, village, and county levels. These projections were prepared
before the 1980 U.S. Census was released, and therefore are based on the 1970
U.S. Census and the growth trends exhibited in the area prior to 1980.
Although the methodology employed to make these projections is sound, the
growth between 1970 and 1980 was less than expected. And the growth between
1980 and 1984 was larger than expected.
TABLE K-l. POPULATION PROJECTIONS FOR THE STATE OF OHIO
AND THE COUNTIES IN THE COLUMBUS SERVICE AREA
Ohio
Delaware
Fairfield
Franklin
Licking
1980
10,797,630
53,840
93,678
869,132
120,981
1990
10,681,863
61,709
98,655
924,592
127,390
2000
10,583,083
71,381
104,033
975,013
132,154
2010
10,398,338
81,164
107,577
1,026,008
136,765
Source: (ODUC, 1985).
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Table K-2 lists the service area population by county as a percent of the
total county population for the same time period. This table indicates that
most of Franklin County's population (over 99%) will be located in the service
area. Less than 1 percent of Fairfield's population and an average of 3
percent of Delaware and Licking Counties will be included in the service area.
Ohio Environmental Protection Agency Projections
Table K.-3 compares OEPA's projections with ODUC's by county for 1980,
1985, and 2000. This table indicates that ODUC currently assumes a slightly
higher growth rate for Franklin County than OEPA used in its earlier
forecasts. ODUC'S projections are based on the 1980 U.S. Census and show a
higher 1980 population in Franklin County than OEPA. In fact, OEPA's earlier
forecasts underestimate the 1980 Franklin County population by 56,000 persons.
OEPA uses higher growth rates for Fairfield, Delaware, and Licking Counties
than ODUC. This results in higher overall population estimates by OEPA for
these counties.
OEPA acknowledges that its 1982 PEMSO estimates may not reflect an
accurate picture of the service area population and has attempted to modify or
revise these estimates. However, since the 1982 estimates are the only
numbers that have been certified by the State, OEPA cannot release the revised
version of these estimates. The growth rates used for Franklin County are
similar for both OEPA and ODUC; this analysis will assume that if OEPA's 1980
population is adjusted to reflect the 1980 U.S. Census, then the two
projections will be more closely aligned. This adjustment, referred to
hereafter as OEPA (adj.), is reflected in Table K-2 as part of the comparison
for Franklin County. Since Fairfield, Delaware, and Licking Counties combined
comprise 1 percent of the total service area population in 1980 and 2 percent
of the total service area population in 2015, no adjustments were made for
these counties.
K-4
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u a
o
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cu a
00 •*
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— i 18 01
" U Ol
-3" C C
O> Ol --4
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o w
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K-5
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TABLE K-3. COMPARISON OF POPULATION PROJECTIONS BY
COUNTY FOR THE COLUMBUS, OHIO AREA
County
Source
Franklin
ODUC
OEPA
OEPA (adj.)**
Fairfield
ODUC
OEPA
Delaware
ODUC
OEPA
Licking
ODUC
OEPA
1980
869,132
812,670
869,132
93,678
82,401
53,840
54,779
120,981
125,943
1985
898,345
829,523
887,400
96,120
87,972
57,693
62,320
124,394
137,648
2000
975,013
906,903
971,700
104,033
106,180
71,381
87,810
132,154
162,791
2015*
1,048,000
974,900
1,044,600
109,000
128,500
86,500
123,500
138,000
187,000
*This estimate is a simple extrapolation of OEPA
on previous growth rates and rounded to 500.
**OEPA figures were increased to reflect the 1980
complete explanation).
and ODUC projections based
U.S. Census (see text for
Comparisons
Using the proportions shown in Table K-4 ODUC's county-wide population
estimates were adjusted to reflect the OEPA estimate of the service area
populations. Table K-5 compares OEPA's PEMSO estimate with ODUC's estimates
adjusted to reflect the service area boundaries, and with the OEPA (adjusted)
estimates. A straightline extrapolation was used to estimate the 1988 and
2008 populations. When this table is compared with Table K-6 RFPU population
projections, it shows that ODUC and OEPA (adjusted) estimates are higher than
the RFPU. The difference between the two projections is less than 2 percent
K-6
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which is within an acceptable range for statistical error. This sets the
service area population at a high of 1,020,000 and a low of 950,400 in 2008.
This figure is at most 23,000 individuals greater than the revised service
area projections shown in Table K.-6. These population figures will serve as a
baseline for estimating the growth that would be likely to occur without the
construction of the interceptors.
Revision of RFPU Projections
The RFPU used the Mid-Ohio Regional Planning Commission's (MORPC) traffic
zone population projections as the initial data base for developing the
overall and subservice area population projections. MORPC's traffic zone
system is based on a network of roadway intersections developed in the 1960's
and was updated between 1974 and 1980. This network is based on land use and
traffic patterns and is able to predict population projections, changes in
land use and transportation needs. These projections are a disaggregation of
the ODUC projections for Franklin County. As a result of ODUC's 1985
revisions, MORPC is revising its projections. MORPC will increase its 2010
population projection from 941,341 to 1,027,341 (1,026,000 is the ODUC
estimate) for Franklin County. This increases the forecast population in
Franklin County by 86,000 individuals by 2010.
K-7
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TABLE K-4. POPULATION DISTRIBUTION BY COUNTY FOR
THE COLUMBUS SERVICE AREA
County/Service Area
Franklin
Total Population
Service Area Population
% of total
Fairfield
Total Population
Service Area Population
% of Total
Delaware
Total Population
Service Area Population
% of Total
Licking
Total Population
Service Area Population
% of Total
1980
812,670
810,351
99.7%
82,401
595
.77,
54,779
1,616
3.0%
125,943
3,253
2.6%
1985
829,523
826,868
99.7%
87,972
642
.7%
62,320
1,928
3.1%
137,648
3,722
2.7%
2000
906,903
902,816
99.5%
106,180
796
.7%
87,810
3,131
3.6%
162,791
5,206
3.2%
Source: OEPA, PEMSO Projections, February 1982.
K-8
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TABLE K-5. COMPARISON OF POPULATION PROJECTIONS BY COUNTY
FOR THE COLUMBUS SERVICE AREA
Source
ODUC
OEPA
OEPA (adj.)
1988
925,900
848,600
902,200
Increase
Between
2000 2008 2000-2008
982,600 1,018,000 35,400
911,947 950,347 38,400
976,130 1,052,900 41,000
Source: Interpolation of Tables K-l, K-2, K.-3, K-4.
K-9
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TABLE K-6. REVISED FACILITY PLAN UPDATE POPULATION FORECASTS
Service Population
Service Area 1980 1988 2000 2015
Jackson Pike (1980 Bdry.)
Southerly (1980 Bdry.)
West Scioto (a)
Big Run
Darby Creek
Grove City
Minerva Park
Sunbury-Galena
Big Walnut
Blacklick
Groveport
Rickenbacker AFB
Rocky Fork
TOTAL
NOTES:
(a) A significant portion of
467,153
324,336
(b)
(b)
(b)
15,941
(b)
(c)
(b)
(b)
(b)
(b)
(b)
807,430
the Upper
487,644
336,633
(b)
(b)
(b)
16,601
2,063
(c)
(b)
21,904
3,436
2,146
(b)
870,427
Scioto West
500,294
360,834
31,072
(b)
(b)
17,490
2,187
(c)
(b)
31,034
3,499
2,146
3,305
951,861
Interceptor
511,035
372,344
42,564
(b)
(b)
22,571
2,265
(c)
(b)
35,091
3,542
2,146
3,601
995,159
presently is
served by temporary pump stations and force mains that discharge to the
Upper Scioto East Interceptor. This service area population is included
in the 1980 and 1988 service population of Jackson Pike. By the year
2000, this service population is deducted from the Jackson Pike service
area and allocated to the West Scioto service area, reflecting
construction of the Upper Scioto West Interceptor Sewer.
(b) Area not served during projection period.
(c) Area excluded from analysis. No service planned.
Source: URS Dalton 1986.
K-10
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APPENDIX L
DRAFT
CRITIQUE OF
WATER QUALITY MODELING ISSUES
FOR THE COLUMBUS, OHIO
SUPPLEMENTAL ENVIRONMENTAL IMPACT STATEMENT
-------
Draft
Critique of
Water Quality Modeling Issues
for the Columbus, Ohio
Supplemental Environmental Impact Statement
August 31, 1987
Submitted To:
U.S. Environmental Protection Agency, Region V
230 South Dearborn Street
Chicago, Illinois 60604
Submitted By:
Science Applications International Corporation
8400 Westpark Drive
McLean, Virginia 22102
EPA Contract No. 68-04-5035; D.O. #040
SAIC Project No. 2-813-06-193-40
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1. Introduction
The Columbus Supplemental EIS (SEIS) is being prepared to evaluate the current facilities
planning information for the City of Columbus. Key provisions of the current facilities plan for
Columbus include:
o Upgrading and expansion of the Southerly wastewater treatment plant (WWTP)
o Phase-out and ultimate abandonment of the Jackson Pike WWTP, and
o Re-routing of Jackson Pike flows to the Southerly WWTP.
Future facilities planning activities will address the issue of CSO control at the Whittier Street
storm tanks overflow. The two wastewater treatment plants operated by the City of Columbus
(Jackson Pike and Southerly) are projected to discharge almost"! 80 mgd of treated effluent to
the Scioto River by the year 2008.
A simplified graphic of the locations of point source discharges and riverine features in the
Columbus area is provided below.
River Mile 132
Whittier Street Pumping Station
River Mile 129
Jackson Pike POTV
River Mile 127
Southerly POTW
River Mile 1 1 8
River Mile 1 17
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Facilities planning activities for the City of Columbus, including future (but as yet
unspecified) modifications for CSO control at Whittier Street, involve decisions which will
directly impact water quality in the Scioto River. These decisions include:
o Locations of effluent discharge outfalls
o Quantity of treated effluent released from each outfall, and
o Extent of wastewater treatment prior to discharge.
Due to the Federal government's participation in the proposed project (through the USEPA §201
grant), and the potential for the proposed project to result in significant impacts on the
environment, an environmental review is required. This review is necessitated in the USEPA
procedures for implementation of NEPA.
Results of current and future facilities planning activities will directly affect the three
major point sources (Whittier Street, Jackson Pike and Southerly) which presently influence
water quality in a 30 mile stretch of the Scioto River, in the Columbus area. Because of this
direct relationship between facilities planning decisions and the quality of the aquatic
environment, it is essential that these aspects of project impacts be carefully considered in the
SEIS.
The most common approach to evaluating the water quality impacts related to a WWTP
effluent discharge is through application of a water quality model. The USEPA relies on models
to determine the need for upgrading wastewater treatment plants beyond secondary, and whether
Federal grant monies may be used for such purposes. As an evaluative tool, the model provides a
mathematical simulation of the naturally-occuring physical/chemical processes which
biodegrade, or assimilate, wastes in the receiving water. Through such mathematical
representations, models assist managers in determining whether proposed improvements in
wastewater treatment processes will provide significant benefits to the water quality of the
receiving waters.
Typically, initial model development is followed by a process of model calibration and
verification, with site specific field data, to ensure that the model is faithfully characterizing
and reflecting natural conditions. At this point, individual variables (such as effluent quantity,
quality or total wasteload) can be selectively modified to predict and evaluate the impacts
(positive or negative) on water quality in the receiving water. Permitted effluent limits can
then be established for the discharger. Such limits reflect a quantification of the total excess
wasteload assimilative capacity of the receiving water which is allocated to the subject
discharger (generally, the total available assimilative capacity is not allocated to a single
discharger).
As an aid to the establishment of wasteload allocations (WLA) and related permit discharge
limits, a water quality model was initially developed for the Scioto River, in the Columbus
vicinity, by the Ohio EPA (OEPA), using QUAL2 (a commonly used, reliable framework). Based
on this model, the OEPA proposed permit limits for the Jackson Pike and Southerly POTWs, in
the Comprehensive Water Quality Report (CWQR).
The original QUAL2 model was later updated, by a consultant to the City (URS Dalton), and
L-3
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transformed to a QUAL2E format, which is operable with PC hardware. The updated model was
then used to derive alternate wasteload allocations and discharge limits, which were proposed by
the City to OEPA. These alternate allocations and limits were accepted by OEPA and sent to USEPA
in an amended CWQR. To date, the amended CWQR has not been approved by the USEPA, however
the discharge limits have been approved. The discharge limits in the amended CWQR are the
basis for the current facilities planning efforts and a key component in the SE1S evaluations.
Therefore, in order to determine if the proposed project will significantly impact the quality
of the natural environment, it is necessary to determine the accuracy of the wasteload
allocations and resultant discharge limits. This determination is made through examination of
the reasonableness of variables and assumptions on which the model was constructed, and
through assessment of the reliability of these variables and assumptions to represent natural
conditions.
Preliminary evaluations conducted as part of the SEIS have questioned a variety of the
variables and assumptions used in the QUAL2E model and resultant discharge limits. Although
these questions are currently unresolved, they include technical input variables to which the
model is especially sensitive. Collectively, these questions seriously undermine the reliability
of the current model.
In the following sections, the questioned model input variables and assumptions are identified
and discussed.
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2. Technical Issues
This section includes an identification of specific model input variables and assumptions
whose reliability is considered questionable, as a result of preliminary SEIS review efforts.
2.1 Existing Modeling.
Two attempts were made at developing a water quality model for the Scioto River near
Columbus, Ohio. The first model was developed by the OEPA using the computer program QUAL2
(SEMCOG). This model was calibrated with water quality data collected during a July, 1982
"intensive survey", and verified with similar data collected in August, 1981. The second
modeling effort was conducted by the City of Columbus and its consultant, URS-Dalton. An
updated version of QUAL2, QUAL2E (enhanced), was used in the second effort.
The major difference between the two efforts, other than the computer program employed,
was that URS incorporated a term to account for the production of oxygen by the benthic
(attached) algae that staff members observed growing in the river during a field reconnaisance
survey in September, 1985. The OEPA had not included the effects of benthic algae or
phytoplankton in its earlier (QUAL2) model of the Scioto.
Two major problems are associated with the existing water quality modeling. The first
problem is that steady state modeling frameworks (ie; QUAL2 and QUAL2E) were applied to
stream conditions that were essentially not at steady state. The second major problem stems
from the use of a benthic photosynthesis oxygen production term. In constructing both models,
rate constants were derived through analysis of field data on physical/chemical parameters in
the river. However, comparison of the field data and the resulting calibration and verification
plots has indicated that acceptable fits to DO data were not obtained in either study.
Other problems include inappropriate or incomplete consideration of ammonia data, other
nitrogen species, phytoplankton, and cross-sectional profiles.
2.2 Steady State Modeling Framework.
Modeling frameworks such as QUAL2 and QUAL2E are normally applied to situations in which
none of the state variables (the concentrations of DO and other water quality constituents) or
"forcing functions" (effluent and boundary BOD, nitrogen loadings, etc.) vary at any given
location with respect to time, i.e., when the system is at "steady state". However, it is often
acceptable to apply steady state models to certain non-steady state situations. For example,
steady state models are often used to model estuaries. However, the model is constructed with
data gathered at high or low slack tides, and is therefore tidally-averaged. In this way, any
error introduced by using a steady state framework to model a dynamic, periodically varying
estuary is reduced.
Similarly, in streams, when a state variable such as DO varies at specific locations due to
such dynamic processes as photosynthesis, error is introduced into the output of a steady state
model. If such time variation in the inputs or state variables occurs, and steady state models are
the only practical tools available, care must be taken to consider the effects of any time variable
L-5
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factors in order to minimize the model error resulting from the use of the steady state
framework. As in the preceding estuarine example, error minimization is usually accomplished
by time-averaging the data over the period of concern (e.g., periods of darkness, periods of
light).
Non-steady state conditions occurred in the Scioto River near Columbus during the July,
1982 intensive survey. Streamflows were observed to decline steadily during this survey,
reflecting the effects of a moderate rainfall event which had occurred just prior to the start of
sampling. Therefore, background BOD and NOD loadings, and velocities and depths throughout the
system, were also declining. More significantly, a diurnal DO variation of greater than 2 mg/L
was measured at several of the sampling stations (as indicated in Figure 6-7 of the Central
Scioto River Mainstem CWQR). At several of the most downstream stations sampled,
supersaturated DO conditions occurred during the early evening hours. Thus, true steady state
conditions were not realized in the Scioto during the July intensive survey.
Steady state model error due to non-steady state effects, such as variable waste loading, can
be reduced by considering individual "plugs", or parcels, of water. In plug flow sampling,
unique parcels of water are followed and sampled as they move downstream, at intervals
according to the expected time of travel (determined from dye studies conducted concurrently, or
at similar streamflow). Each plug is then treated as a separate water quality sampling run,
from which a predicted profile can be generated using the corresponding inputs. However, no
data have been collected from the Scioto River from which such a plug flow model can be
developed.
No steady state model, no matter how carefully developed, will allow an accurate prediction of
the DO time series as impacted by photosynthesis. QUAL2E may be run in the dynamic mode,
which will allow the development of a model to predict the time-variable effects of
phytoplankton (but not periphyton algae) on the instream DO and nutrient profiles. While
inputs and forcing functions (i.e. effluent and background Streamflows, BOD and NOD loadings,
and DO concentrations) must remain constant, the variation in stream DO concentrations due to
diurnal variation in algal photosynthesis can be simulated. However, QUAL2E does not have the
capability to properly simulate benthic photosynthesis which, apparently, may be quite
significant in the Scioto River. To successfully accomplish the simulation of benthic or
planktonic algae over time, detailed knowledge of the algae nutrient uptake kinetics and
light-growth relationships are required. This knowledge is preferably gained from
site-specific studies which, in the present case, are lacking for the intensive survey periods. In
an attempt to compensate for these deficiencies, literature information would have to be used as
initial values for most of the parameters.
In both existing versions of the model, all of the observed DO data points for the four-day
survey were used in calibrating the model. However, these DO values were taken from samples
collected in both the morning and afternoon hours. Simultaneously calibrating to both morning
and afternoon DO observations resulted in the underprediction of the afternoon, and
overprediction of the morning, DO profiles. Only 11 of 50 observations were from the morning,
and none were from before 9:30 am. Since most of the DO values used for calibration were from
the afternoon hours, when DO will be at its highest level of the day, the resulting predicted DO
profile was skewed towards a higher level than it probably should have been. This procedure
L-6
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disregards the night and early morning hours, when DO is usually at its lowest level. (Note that
the DO concentration measured at river mile 118.5 at 9:30 am on July 21,1982 was 3.9 mg/l,
which was the lowest value observed during the entire survey.) In the URS model (QUAL2E),
inclusion of the benthic photosynthesis term resulted in an even higher mean DO profile than the
OEPA model (QUAL2), based on the same sampling data.
As an alternative, it might be appropriate to segregate the water quality data with respect to
the date and time sampled, i.e. to "time-average" the data. The use of a steady state model could
then be better justified, perhaps by calibrating separately to morning (low DO) and afternoon
(high DO) observations, or by assigning weights to each observation so that a more realistic
picture of daily average water quality values could be obtained. Actual mean parameter values
(e.g., Kd, Kn, etc.) could be better estimated in this way, and more accurate predicted profiles
could subsequently be generated.
2.3 Benthic Photosythesis Term in QUAL2E.
The QUAL2E model is an improvement over the earlier QUAL2 model in that it recognizes the
need to include the effects of algal periphyton on DO in the Scioto River. It is apparent from the
URS data that, at times, these attached algae can significantly impact the observed DO profile in
the river. However, the URS model incorporates a negative sediment oxygen demand (ie; benthic
oxygen production). There are numerous pitfalls associated with the use of a negative sediment
oxygen demand (SOD) term in the URS model.
URS' experiment was conducted over a two day period beginning September 25,1985.
During this period, it was generally sunny, but periods of clouds and rain occurred on the 26th.
During the periods of cloud cover on the 26th, a net consumption of oxygen was measured in the
DO chambers, which would be expected. During the sunny periods, a net production of oxygen
was observed. By plotting the change in DO in the chambers and bottles over time, URS derived
slopes, in mg/Umin, of the oxygen depletion curves. It is not stated whether these slopes
represent averages over the entire experimental period, or instantaneous maxima. However,
only the results of the experiments on September 25, when a net production of oxygen was
occurring, were used to calculate the "overall" net 24 hour SOD of -1.74 g/m2/day (the
negative sign implies a net production of oxygen).
The applicability of this SOD rate to a model calibrated with data collected three years prior
to these experiments must also be questioned. Stream conditions, such as substrate composition
and nutrient availability to adequately support benthic algae growth, can change in three
years, especially in a relatively small, wastewater-dominated stream such as the Scioto. Also,
the sunlight conditions that greatly influence the rate of oxygen production were much different
during the July 1982 study period. URS reports that sky cover ranged from 0% to 100%
during the survey period. However their SOD rate was derived from an experiment conducted
only during bright sunshine. In addition, the experiments were conducted at only one station,
located between the Jackson Pike and Southerly discharges. This rate was applied to all of
reaches in the model, except in those reaches where the predicted DO greatly exceeded
observed values. In those cases, the SOD term was arbitrarily removed in order to "fit" the
observed DO data.
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Finally, there is also the difficulty in determining a "design condition" SOD rate for use in a
WLA model. No precedent or EPA guidance exists in applying a net benthic oxygen production
term for use in a WLA model. Before using a term in the model which has little or no literature
justification, and which appears to have been used mainly to better fit the data representing
higher DO concentrations, additional data collection should be required to support its use.
2.4 Other Significant Problems.
In addition to the major technical problems discussed in the preceding sections, several
additional problems are noted. These additional problems are discussed in the following.
2.4.1 Phytoplankton Influence on DO Profile.
Neither model accounted for the influence of phytoplankton on the DO profile of the river.
This is especially apparent in the lower reaches of the Scioto (below river mile 109) where
significant populations of phytoplankton apparently caused supersaturated DO conditions. In
addition, elevated ultimate CBOD values were also observed beginning at river mile (RM) 109.
Chlorophyll a samples taken in September, 1982 during a diurnal DO study conducted by OEPA
indicate that this section of the river is probably impacted by an active phytoplankton
population. (In bottle BOD tests, the presence of algae in the samples can increase the measured
ultimate BOD considerably over that which is traceable directly to wastewaters.) However, the
OEPA CWQR mentions that "algal simulations were not performed. With the information
available, the QUAL-II model could not be accurately calibrated to the Scioto River."
URS attempted to incorporate the effects of phytoplankton in their WLA analysis, and a
sensitivity analysis of the effects of phytoplankton on the DO profile under design wasteflow
conditions was conducted. The analysis showed that an increase in DO of only 0.14 mg/L would
be expected if the phytoplankton population were to increase from 0 to 100 ug/L. This
contradicts the July and September, 1982 data presented by OEPA, where significant increases
in afternoon DO were observed at the most downstream stations, correlated with high
chlorophyll a levels. URS provides no information in the report concerning values for algal
kinetics or cell stoichiometry parameters used in the sensitivity analysis.
2.4.2 Nitrogen Species.
The QUAL2E model does not appear to be successfully calibrated for NH3-N and NO2+NO3-N,
and organic N was not modeled. Figures 6-5 and 6-6 of the CWQR appear to indicate an
erroneous value for the nitrification rate coefficient. Observations for both ammonia and
nitrite-nitrate nitrogen are generally underpredicted. This carries over, although to a
somewhat lesser extent, to the verification profiles for these variables given in Figures 6-9 and
6-10 of the CWQR. This could stem from not accounting for the effects of algal uptake on
nutrients in the model.
Organic nitrogen was not considered in either model. Organic N can hydrolyze to produce
ammonia, which can then be taken up by algae or oxidized by nitrifying bacteria. Inclusion of all
of the nitrogen species, as well as the effect of algal uptake, may result in a closer
correspondence between observed and predicted values.
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2.4.3 Cross Sectional Profiles.
Cross sectional profiles provided by the OEPA do not indicate significant variation in cross
sectional area or depth. OEPA established 25 reaches based on times-of-travel, river cross
sections and flows observed during studies conducted in 1980-1981. Each of these reaches is
characterized by a unique power function for flow vs. velocity and flow vs. depth. However, none
of the information required to assess the flow-velocity or flow-depth power equations presented
in Table 6-2 (flows, times-of-travel, depths for each reach) is given in the report.
Flow vs. velocity and flow vs. depth relationships affect the model's internal calculation of
reaeration, and the rate of transport of pollutants through the system. Therefore, it is critical to
properly define these relationships to correctly predict the DO response to changes in flow,
especially when determining the WLA. However, predicted stream depths developed in the
QUAL2E model do not appear to correlate with actual field data. For example, if a flow of 150 cfs
is used, the depth equations for reaches 2 and 4 yield depths of 2.8 and 1.8 feet, while the
equation for reach 3 yields 0.7 feet. In contrast, based on observation of the profiles submitted
by OEPA, there do not appear to be any locations that were sampled that have a mean depth of less
than two feet.
Since the shapes of the cross sectional profiles appear to be relatively uniform, it may be
more appropriate to divide the study area into fewer physical reaches, so that less variation in
depths is obtained. It is accepted modeling practice not to divide a stream system into any more
reaches than is necessary, especially if a general physical uniformity throughout the stream is
observed.
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3. Conclusions and Recommendations.
Based on the reviews conducted to date, it does not appear that an accurate and reliable
predictive model for use in assessing current and future environmental conditions has been
developed. This is most likely due to limitations in the available data, and to the inability of
QUAL2E to simulate diurnal DO variations in the steady state mode. Specific conclusions and
recommendations concerning the existing water quality models are listed below.
3.1 Algal Effects on DO.
The contribution of dissolved oxygen by algae to the stream DO balance is not usually
accounted for in determining assimilative capacity. However, an attempt should be made to
factor the effects of algae on DO into the modeling for the Scioto River, using the September,
1982 diurnal DO data. Any assumptions on daytime oxygen production by algae must be balanced
against the catastrophic effects that nighttime respiration of these cells can have on DO, and
subsequently on stream biota.
A diurnal DO study was conducted in September, 1982. Some extremely low DO values were
observed, and most values recorded were below the 5 mg/L DO standard. However, the number
of samples and their times of collection were not reported in the Draft CWQR. The appropriate
data for developing an accurate and reliable model of algae in the Scioto for the July, 1982
survey are apparently not available. Thus, it may be difficult to improve on either modeling
effort for that period, given the existing data set. However, it may be possible to use the diurnal
data collected during September, 1982 to formulate a model of the river which includes the
effects of algae on DO. This data set should be analyzed for its potential use in model development.
3.2 Benthic Algae/SOD.
The effects of benthic algae on SOD should not be incorporated into the WLA model until a
more complete set of data is available. More studies similar to the URS SOD study should be
conducted before a term describing the benthic production of oxygen is incorporated into the
model. Due to the existence of the Whittier St. CSO and periodic bypasses of the Southerly
WWTP, organic solids introduced into the river during storm events may settle out in the study
area and result, at times, in a benthic oxygen demand that exceeds the production of oxygen by
benthic algae. This needs to be considered in establishing a steady state net SOD term for use in
the model.
3.3 Non-steady State Modeling.
The feasibility of using a non-steady state modeling framework should be explored. USEPA
has developed WASP, a multi-purpose dynamic modeling framework that can be used to simulate
the effects of phytoplankton on nutrients and DO in streams as well as other types of water
bodies. The available body of data should be examined carefully to determine whether WASP, or
any other similar framework, may be a more appropriate tool for modeling the Scioto River
than QUAL2E.
Although WASP is more flexible than QUAL2E, it is also more complicated and, therefore,
L-10
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more costly to develop and utilize.
3.4 Additional Data.
The feasibility of collecting an additional set of data should be examined. The shortcomings of
the available data upon which to build a valid water quality model for the Scioto River have been
described by the OEPA and URS. The basic problem is that water quality samples were collected
without regard to plug flow in the system. Due to the time variability of DO in the Scioto during
low flows, the assumption of steady state (which is crucial to the successful utilization of
QUAL2E as the modeling framework) is invalidated.
Also, the depth and velocity vs. flow relationships were developed for flows that may be
exceeded as a result of plant expansion in the future. New information collected at higher flows
in the Scioto would decrease the uncertainty in the results produced by these equations.
3.5 Evaluation of Alternatives.
Because the existing models were developed under a two-discharge scenario, these models
should not be used to evaluate the one-plant alternative without further data collection and
modeling analysis. It is likely that, under a one-plant scenario, the water quality impacts of the
Southerly plant will extend even farther downstream during 7Q10 flow events than presently
occurs.
The existing models extend downstream only to RM 103, near Circleville. Beyond RM 103,
there is no information - physical, hydrologic or chemical - on which to base model
development. Furthermore, there are other large industrial discharges below RM 100 whose
effluent limits may be impaired by the downstream relocation of the DO sag likely to occur due to
the combination of flows in a one-plant scenario. This data deficiency needs to be corrected
before a reliable model of this section of the river can be constructed.
L-1 1
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APPENDIX M
U.S. ENVIRONMENTAL PROTECTION AGENCY,
WATER QUALITY BRANCH, MEMORANDUM
ON COLUMBUS WATER QUALITY MODEL
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION V
DATE: SEP 30 1987
SUBJECT: Columbus, Ohio Water Quality Modeling
i ^^**^~^
FROM: Kenneth A. Fenn>
Water Quality
TO- /"
Todd A. Cayef, Chief
Municipal Facilities Branch
i1
In response to your memorandum of September 9, 1987, regarding the
water quality modeling for Columbus, Ohio, my staff has reviewed the
EIS consultant's (SAIC) critique of the modeling work performed by
OEPA and later work completed by URS-Dalton for the City of Columbus.
As you may know, the original OEPA two-plant modeling analysis for
Jackson Pike and Southerly was reviewed by the Eastern District
Office, the Planning and Standards Section and our Permits Section.
These offices found the original QUAL II analysis to be sound.
OEPA effort resulted in the following limits:
Plant River Mile Flow CBODt
Jackson Pike
Southerly
127
118
110 MGD
85 MGD
5.2 mg/1
5.0 mg/1
NH-3-N
1.3 mg/1
1.5 mg/1
Subsequently, the City of Columbus employed URS-Dalton to model the
Scioto River as a means of confinning the State's analysis and for
exploring a one-plant alternative. URS-Dalton employed lower flow
discharge projections, and concluded that the following limits would
achieve dissolved oxygen and ammonia water quality standards:
Plant
Jackson Pike
Southerly
Jackson Pike
Southerly
As you can see, the results are comparable, with a decrease in
ammonia that allows slightly higher CBODs values. We would also
point out that these limits approach those achievable with available
technology,
M-l
Time
Pre-1992
Pre-1992
1992-
1992-2015
Flow
60 MGD
90 MGD
Dec
156 MGD
CBODs
8.0 mg/1
8.0 mg/1
o m m i s s i
8.0 mg/1
NHyN
1.0 mg/1
1.0 mg/1
o n e d
1.0 mg/1
EPA FO8M 1320-6 (REV. 3-76)
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In terms of the critique by SAIC, we agree that model calibration
and verification would be improved with further work on stream
hydraulics and algal kinetics. However, we can make this same
statement regarding virtually any other water quality model in
Region V and perhaps the rest of the Country. Furthermore, it does
not always follow that a better calibration of existing conditions
would necessarily improve the prediction of future conditions.
This is because future conditions will be dramatically different
due largely to changes in hydraulics and the control of both point
and nonpoint sources of pollution. For these reasons, professional
judgment is an overriding factor in developing and applying a water
quality model. The current model may have an error margin of
+1.0 mg/1 of dissolved oxygen. Given the complexity of the Scioto
River in this area, we are not convinced that future modeling work
will either significantly reduce this error or significantly revise
the current effluent limitations.
We agree with the Environmental Review Branch that further modeling
of the one-plant vs. two-plant alternative seems counterproductive.
This is because reasonable estimates of the one vs. two-plant
approach are available to your staff. We have endorsed the two-plant
analysis developed by URS-Dalton which is the basis for the current
permit limits at each facility.
We also agree that OEPA may be able to provide additional professional
judgment if that is deemed necessary for the purpose of the EIS.
M-2
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APPENDIX N
THE INFRASTRUCTURE PROJECT 1985-1986
FINAL REPORT: EXECUTIVE SUMMARY
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m
DEVELOPMENT COMMITTEE FOR GREATER COLUMBUS
THE INFRASTRUCTURE PROJECT
1985-1986
FINAL REPORT
5 DECEMBER 1986
N-l
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y
"While the space directly beneath a
building contains the systems required to
support its structure, the area under the
surface of the streets and sidewalks is filled
with the systems essential to support its
occupants. The basic systems, which we
call utilities, include water, sewage removal
and drainage, electricity, steam, gas, and
telephone communication."
The quotation above & the
cover illustration are from
UNDERGROUND by David
Macaulay. Copyright © 1976
by David Macaulay. Used by
permission of Houghton Mlfflin
Company.
' 'The nation's infrastructure: The physical
framework that supports & sustains virtually
all economic activity."
Definition by the National
Council on Public Works
Improvement.
N-2
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CONTENTS
Extracts from the "GREATER COLUMBUS INFRASTRUCTURE INVESTMENT
REQUIREMENTS AND FINANCING STRATEGY: THE NEXT FIVE YEARS"
(the Final Report of the DCGC 1985-1986 Infrastructure Project)
Pages
EXECUTIVE SUMMARY v to viii
Section VI. NEXT STEPS:
IMPLEMENTATION 104 - 107
INFRASTRUCTURE MAPPING & INFORMATION SYSTEM
NOTE: The Final Report of the DCGC 1985-1986 Infrastructure
Project will be distributed to all agencies which were
participants in the Project.
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EXECUTIVE SUMMARY
The Development Committee for Greater Columbus undertook a major
study to assess the area's infrastructure condition and to develop
strategies for keeping its capital facilities well managed and
maintained. This report represents the final product of two earlier
reports written by The Urban Institute in February and September 1986.
The first report, Greater Columbus Infrastructure Investment
Requirements (Feb. 1986), evaluates capital facility performance and
determines capital investment requirements and funding availability over
the next five years for area roads, bridges, water, and sewer systems.
The second report, Financing Greater Columbus's Infrastructure (Sep.
1986), provides a detailed analysis of the area's options for financing
its capital program. The present report represents a final statement of
this Greater Columbus Investment Strategy.
GREATER COLUMBUS'S CAPITAL PLANT
o Two indicators of performance — a street maintenance
effectiveness index and resurfacing cycles — suggest that
several jurisdictions are falling behind in road repair. The
City of Columbus, in particular, falls below a sampl*1 of other
large cities in road performance, reflecting a fluctuating
program of maintenance and repair.
o Jurisdictions with high ratings generally show short
resurfacing cycles and more systematic programs of street
resurfacing.
o Based on several performance measures, bridges in the county
are generally in good condition. Only 6 percent are
structurally deficient, the potentially most serious bridge
problem. The older structures that fall largely under county
responsibility, are in the poorest condition.
o Area water supply is adequate to the year 2000, provided
additional sources are identified beginning in 1991.,
o Area water distribution systems show low main breaks relative
to other cities. The level of unaccounted-for-water, at 20
percent, is higher than average, but it is not out of line with
older cities.
o The major performance problem facing the Greater Columbus area
in sanitary sewers is the need to upgrade the City of Columbus'
sewage treatment plants to meet EPA requirements.
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o Condition of area collection systems appears to be adequate.
The City of Columbus and its suburbs fare well relative to
other cities with respect to the number of main breaks and
sewer line back-ups.
o As a relatively new area of infrastructure concern, information
is not readily available on the performance of area storm sewer
facilities.
GREATER COLUMBUS'S CAPITAL INVESTMENT PATTERNS
o The majority o-f area improvements are slated for expansion (46
percent) and upgrading (43 percent) of capital facilities.
Only 11 percent of total investment dollars are targeted for
rehabilitation of existing facilities. The City of Columbus,
in particular, should consider a more balanced division of
resources to insure that existing facilities will be kept in
good repair.
o Approximately half of projected investment requirements over
the next five years can be met from available federal, state,
and local resources.
o The City of Columbus is responsible for nearly half of the
funding shortfall, not surprising in view of the city's major
role as provider of area highway services, water supply, and
sewage treatment. Nearly two-thirds of suburban investment
projects, however, are also unfunded.
o The area shows large projected investments of $454 million over
the next five years for roads, but only 18 percent is slated
for rehabilitation.
o Planned investment requirements for bridges over the next five
years are small relative to other infrastructure areas. The
majority are for rehabilitation and upgrading.
o The City of Columbus system accounts for 90 percent of total
planned water investments. The majority of city investments
are for supply improvements and system upgrading. The majority
of suburban needs are for rehabilitation and upgrading.
o Planned sanitary sewer investments over the next five years
represent the second largest spending area. The majority of
improvements are for upgrading, to meet Environmental
Protection Agency requirements, and for expansion. Only a
small fraction of planned spending is for rehabilitation.
o Planned storm sewer investments over the next five years are
the smallest of all of the infrastructure areas. However,
since several studies are only now underway that could lead to
a higher needs estimate.
N-5
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THE COST OF RENEWING GREATER COLUMBUS'S CAPITAL FACILITIES: REASSESSING
THE AREA'S NEEDS
'The Development Committee for Greater Columbus (DCGC) and the Mid-
Ohio Regional Planning Commission (MORPC) with guidance and input from
local area officials prioritized an initial list of capital projects
according to several criteria such as funding availability, health and
safety standards, and impact on the local community. The effort
produced a list of priority projects and an estimate of the funding
shortfall expected for 1987-1991.
o Investment requirements across all infrastructure areas and
jurisdictions were reduced from $1.05 billion (1986-1990) to
$946 million (1987-91). The funding shortfall declined by 9
percent, from $500 million to $457 million.
o Funding shortfall as a percentage of total planned capital
investment is 48 percent.
o Sanitary sewer projects represent 39 percent of the total
investment; storm sewers 2 percent. Capital spending for water
systems are 8 percent of the total. Road and bridge
improvement expenditures comprise 47 percent and 5 percent of
total investments, respectively.
o Sanitary sewers comprise about 35 percent of the total
shortfall. Road funding shortfalls account for 54 percent.
Funding shortfalls in the water area amount to 2 percent;
bridges 7 percent of the total shortfall.
o The shortfall as a percent of total investment requirements in
each infrastructure area is greatest in bridges, at 67%,
followed by: roads, 567.', sanitary sewers, 44%; storm sewers,
31%; and water, at 11%.
o The City of Columbus comprises the bulk of total area
shortfalls in roads, bridges, and sanitary sewers. The growth
suburbs account for most of area shortfalls in water systems
and storm sewers.
FINANCING CAPITAL REQUIREMENTS
o Proposed financing mechanisms to support infrastructure
requirements should be consistent with accepted public finance
practice: large scale investments should be debt-financed;
debt issuance should be by jurisdictions with the greatest
overall responsibility for area infrastructure; improvements
should be paid for by those who directly benefit from the
improvements.
N-6
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o The bulk of area road and bridge requirements could be
supported with modest increases in user charges: $10 increases
in license tag fees; a 2C per gallon local fuel tax; an
extension of the county sales tax to gasoline.
o Other road and bridge funds required could be raised through
developer contributions, so that the increased capacity needed
to service growth is supported by those who create added
demand.
o The Columbus area appears to have a strong claim on increased
ODOT discretionary funds, which historically represent a
smaller share than total road mileage responsibility.
o Most jurisdictions with water and sewer funding shortfalls
could support the required investment with increases over
current rates. The remaining jurisdictions likely will have to
partially support investment requirements through general fund
support.
o The creation of a storm-water management district represents
the best avenue for handling the area's flood and drainage
investment requirements.
o Institution of a comprehensive, automated, infrastructure
mapping and information system, including inventory, condition,
and investment data across jurisdictions and sectors, would
encourage better infrastructure management, and ensure reduced
long-range capital requirements through improved maintainance
programming for existing infrastructure.
N-7
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VI. NEXT STEPS: MPLEMEHIATIOH
The development of a comprehensive analysis of Greater Columbus's
infrastructure and financing opportunities represents the first step in
a capital stock investment and management strategy. The main objective
lies ahead: translating this strategy into concrete action. This will
require a coordinated effort to educate the public as to its importance,
secure authorization from the General Assembly for key steps in the
financing plan, cement, local cooperation regarding the choice and
financing of capital priorities, and ensure the collection and automated
storage of the information needed to wisely choose among capital
projects, and between capital and maintenance expenditures.
Taxpayer/Voter Approval
The financing plan contemplated in this report places on local
highway and utility service users the responsibility for financing
improvements to these same services. In the area of roads and bridges,
increased fees and charges can support general obligation borrowing by
the County to support area-wide investment. This requires authorization
of general obligation bond issues by the Franklin County Commissioners,
and approval by county voters.
The rate increases required to fund utility system investments do
not require general voter approval. However, city councils will have to
support increases of the needed magnitudes to cover borrowing
requirements, or authorize the expenditure of general fund revenues to
meet extraordinary investment costs. In contrast to the multi-
jurisdictional approach needed to address area road and bridge
N-8
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Investment, increased funding for water and sewer investment is a
decision for each system, in each community.
State Legislative Change
The first action required of the state is to modify the current
limitation on the county vehicle license fee. Instead of the current $5
ceiling, counties should be allowed to increase the license fee, either
by a designated amount or according to locally perceived needs.
State action also will be required to permit local imposition of
fuel taxes. Since the 2c increase in the gasoline tax is the major
source of planned new revenues to support road and bridge investment,
this approach should have a local priority. In addition, the decline in
fuel prices offers a window of opportunity to impose an a^itional fee
at a time when the Impact on consumers will be minimal. Similarly,
State approval will be required to permit extension of the county sales
tax to gasoline. As this would not represent an increase in the tax,
but an increase in the taxing base, resistance to this approach should
be somewhat muted.
Local Goveraeat Cooperation
Area governments already have demonstrated willingness to cooperate
in a coordinated infrastructure renewal effort by participating in the
DCGC's Greater Columbus Community Capital Investment Strategy effort.
However, many specific project priorities remain to be negotiated, a
process requiring continuing good will and cooperation among all
governments in the County*
N-9
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A cooperative agreement will have to be negotiated between the City
of Columbus and Franklin County to determine the specific road and
bridge projects to be financed from a County bond issue, and the
sequencing of repair work. In addition, suburban jurisdictions will
have to reach their own accomodation with the County in slating local
road projects for renewal. The DCGC has a vital role to play in
sustaining the areawide cooperation that has developed during this first
project effort.
The creation of a storm-water management district represents the
best way to finance areawide flood and drainage improvements. The
structure of such a district remains to be worked out among the
prospective participants, for example, the rights and terms of entry and
withdrawal, the allocation of investment, and the type and level of
service charges. Though difficult, this process will result in a secure
mechanism for storm-water funding.
Improved Coordination and Manageaent of Capital and Maintenance Spending
The overall Community Capital Investment Strategy effort till now
has focused primarily on capital investment needs and funding
requirements. The immediate thrust of this effort is to remedy any
investment backlogs, and ensure that the facilities needed to accomodate
new population and economic growth are in place. However, the Columbus
area faces a unique opportunity to reduce long-run capital investment
requirements. The complex interrelationship between ongoing maintenance
spending and capital improvements requirements is long-recognized but
not always considered as a basis for action. By acting now to improve
local infrastructure management, area jurisdictions can ensure that the
N-10
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existing, and planned, capital stock, is adequately maintained, thus
forestalling more costly future investments in infrastructure renewal.
The creation of a comprehensive, multi-jurisdictional, automated
geographic information and mapping system would be an important, indeed
critical, step in improved capital planning.
Such a system would store and display inventory and condition
information, and combine water and sewer distribution system
information, street and bridge information, including traffic data,
zoning and land use data, demographic and economic information, and
virtually aay other information to allow an assessment of service demand
for any infrastructure link. With the addition of maintenance and
repair history data, area infrastructure managers can plan for cost-
effective maintenance investment, to ensure the longest useful life of
any capital asset. In addition, capital Investments across sectors can
be coordinated to ensure cost-effective repair and minimal disruption;
for example, through the sequencing of street repairs and water line
replacement.
The cost recovery period of an investment in infrastructure
management systems can be quite short. The City of San Jose estimated
their system investment at $3.3 million, with annual operating costs of
$705,000. The annual benefits expected were $995,000 for avoidance of
higher future replacement costs; $1,020,000 for increased maintenance
productivity; and $75,000 for reduced costs of tort settlements and
insurance. The initial capital investment would be repaid in 2.5 years.
N-ll
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INFRASTRUCTURE MAPPING & INFORMATION SYSTEM
A timely recommendation by the Urban Institute is for the
"institution of a comprehensive, automated infrastructure mapping
and information system..." The recommendation is considered
timely due to a great amount of interest locally and activity
nationally in such systems. Variously known as a "Geographic
Information System" (CIS in Chattanooga, Tennessee), a "Mapping
and Geographic Infrastructure System" (IMAGIS in Indianapolis),
"Mapping Oriented Information System" (MOIS at American Electric
Power), "Automated Mapping/Facilities Management" (AM/FM for the
U.S. Air Force, Consolidated Gas Transmission Corporation of
Clarksburg, West Virginia,...and others), or some combination,
such as AM/FM-GIS, in Seattle, the systems are basically similar.
For sake of simplicity, here and until a better acronym is
devised - we will refer to the system as AM/FM.
An important part of the DCGC Infrastructure Project has
been gathering information concerning AM/FM. We have found a
wealth of experiences available for reference as the Greater
Columbus community investigates developing an AM/FM system.
Many agencies admit to having come to a realizat.'jn that
they are having difficulties and high costs in their mapping and
information systems.
These were well summarized by Peoples Natural Gas Company
of Pittsburgh as due to:
"redundancy of data due to decentralized divisions;
update delays to complete a record; difficulties in
researching data due to the independent maintenance of
varying documents; inadequacies for special applications
such as network analysis; and expensive maintenance
costs since the effort was very labor intensive."
They continue by stating:
"The Peoples Natural Gas Company feels that a
corporate Facilities Information Management System
with computer graphics has enormous potential. Consi-
dering the changing needs of the gas industry for
extensive record keeping, mapping and design, we must
pursue means to improve the effort."
Statements repeated often by utility companies and metro-
politan areas are that the high costs of AM/FM systems can be
made acceptable by forming coalitions and thereby sharing the
system and costs. Repeatedly, the experienced voices in this
new industry of AM/FM urge adequate planning and project
definition as being crucial to the success of an AM/FM project.
N-12
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Some experiences have been of starting over, or regrouping,
as stated in the following concerning Seattle:
"The City of Seattle Joint Automated Mapping Project
began as individual efforts by four separate City agencies.
The City's Budget Office, recognizing their commonality,
initiated this joint project. The City is currently con-
ducting a unique pilot project intended to develop cost
estimates of conversion of the City's land and utility
facilities data base and to provide a better understanding
of AM/FM-GIS system capabilities and related implementation
procedures and processes. The pilot project was developed
by the City participating agencies jointly following an
evolutionary process. The process of development of a
request for proposal for a consultant to complete the pilot
began with an agreement on goals and objectives, included
identification of candidate applications and development of
a pilot project approach, and concluded with a memo of
agreement, or charter, between the agencies assuring
commitment of adequate resources (dollar and personnel) to
the pilot. Key to the success of this process and to the
success of the project itself, is the ability of project
management to (1) maintain management commitment to the
project, (2) continue an open communicative, synergistic
decision process, and (3) assure sufficient resources in
the leadership role. With these factors, the cooperative,
i.e., joint, nature of the project can be maintained through
the pilot and into an implementation decision process.
In summary, management commitment, an open process, and
leadership support have forged a team effort from the
initial set of individual agency, or turf, interests."
In conclusion, we will report a statement from the Coachella
Valley Water District (California) Deputy Chief Engineer:
"CAD is here to stay - AM/FM is on the way I
When? How soon? No one has the answer today. The
only statement that can be made to a certainty is that
AM/FM is as inevitable to the District and to all similar
public agencies as data processing was 15 or 20 years ago."
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APPENDIX 0
SEIS DISTRIBUTION LIST TO
PUBLIC GROUPS AND OFFICES
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Federal Agencies
U.S. Department of Agriculture
U.S. Department of Commerce
U.S. Department of Defense,
Army Corps of Engineers
U.S. Department of Housing and Urban Development
U.S. Department of Health and Human Services,
Public Health Service
U.S. Department of the Interior,
Fish and Wildlife Service
National Park Service
U.S. Department of Labor
U.S. Department of Transportation,
Coast Guard
Federal Highway Administration
Ohio Congressional Delegation,
U.S. Senators
U.S. Representatives
State of Ohio
Building Industry Association of Ohio
Office of the Governor
Ohio Office of Management and Budget
State Clearinghouse
Ohio Environmental Protection Agency
Ohio Department of Natural Resources
Ohio Department of Public Health
Ohio Department of Transportation
Ohio Department of Justice
Ohio Department of Economic and Commercial Development
Ohio Department of Energy
Ohio Water Development Authority
Ohio Department of Agriculture
Ohio Federation of Soil and Water Conservation Districts
Ohio Historic Preservation Office
Ohio Attorney General
Ohio Department of Parks and Recreation
Ohio Utilities Company
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Local
Capital Square Commission
City of Bexley
City of Gahanna
City of Grandview
City of Grove City
City of Hilliard
City of Reynoldsburg
City of Upper Arlington
City of Worthington
Clinton Area Commission
Columbus Dispatch
Columbus Health Department
Columbus Industrial Association
Delaware County Regional Planning Commission
Fairfield County Regional Planning Commission
Franklin County Farm Bureau
German Village Commission
Greater Hilltop Area Commission
Hamilton Township
Italian Village Commission
Logan-Union-Champaign Regional Planning Commission
Madison County Regional Planning Commission
Mid-Ohio Health Planning Federation
Mid-Ohio Regional Planning Commission
Near East Area Commission
Northeast Area Commission
Pickaway County Regional Planning Commission
Public Library of Columbus and Franklin County
Rickenbacher Air Force Base
South Linden Area Commission
University Area Commission
Village of Brice
Village of Canal Winchester
Village of Dublin
Village of Galena
Village of Harrisburg
Village of Johnstown
Village of New Albany
Village of New Rome
Village of Obetz
Village of Orient
Village of Pataskala
Village of Plain City
Village of Riverlea
Village of Urbancrest
Village of Valleyview
Village of West Jefferson
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Public Interest Groups
American Association of University Women Great Lakes Basin
Task Force
Archaeological Society of Ohio
Audubon Society of Ohio
Citizens for a Better Environment
Citizens Advisory Council
Citizens for Good Planning
Columbus Board of Realtors
Environmental Clearinghouse, Inc.
Environmental Defense Fund
Franklin County Health Department
F.U.T.U.R.E.
Future Farmers of America
Greater Cleveland Growth Association
Izaak Walton League
League of Ohio Sportsmen
League of Women Voters of Ohio
Natural Wildlife Federation
Nature Conservancy of Ohio
Ohio Academy of Sciences
Ohio Air Quality Development Authority
Ohio Biological Survey
Ohio Chamber of Commerce
Ohio Conservation Foundation
Ohio Conservation Fund
Ohio Electric Utility Institute
Ohio Environmental Council
Ohio Environmental Health Association
Ohio League of Conservation Voters
Ohio Natural Areas Council
Ohio State University
Ohio Natural Heritage Program
Ohio Sierra Club
Ohio Soil and Water Conservation Commission
Ohio Water Pollution Control Conference
Ohio Water Resources Center
Sciota Bass Anglers
Water Pollution Control Federation
Water Resources Council
Wildlife Legislative Fund
Interested Citizens
Complete list available upon request.
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