Barberton Reservoir Oxygenation Cost Estimate
Dean Morningstar
Department of Civil Engineering
Honors Research Project
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•
SENIOR HONORS PROJECT
Barberton Reservoir Oxygenation
Cost Estimate
Prepared By:
Dean Morningstar
Date:
04/22/11
Table of Contents
Section
Page
List of Figures .
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List of Tables .
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Abstract
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Introduction
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1
Background
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2
Electrical Power Considerations
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3
Site Access Considerations
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5
Cover Building Considerations
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Conclusion
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9
Appendices
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10
A. Full Warehouse Building Estimate
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B. Full Building Cost By Assembly Table .
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C. Barberton Reservoir Oxygen Deficit EvaluationHypolimnetic Oxygenation Assessment .
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11
13
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15
Previous Study Findings
Barberton Reservoir Oxygenation Cost Estimate
List of Figures
Figure
Page
1. Barberton Reservoir .
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1
2. Phase Diagram For 3 Phase Electricity
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3
3. Current Overhead Electricity .
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3
4. Approximate Concrete Truck Dimensions
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5
5. Reservoir Entrance from Summit Road
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6
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List of Tables
Table
Page
1. Associated Electrical Costs
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4
2. Associated Access Costs
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5
3. Warehouse Building Estimate.
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7
4. Building Cost by Assembly .
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8
5. Final Cost Options
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9
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iii Barberton Reservoir Oxygenation Cost Estimate
Barberton Reservoir Oxygenation Cost Estimate
Dean Morningstar
Abstract:
Since completion of the new membrane filtration process at the Barberton Water Treatment
Plant, many complaints of odd tasting water have been reported. Studies in the past few years
have concluded that the cause is a seasonal rise in the manganese content of the water. This was
not an issue prior to the membrane system as the previous system included sand filters which
removed much of the manganese. As reinstalling the sand filters is not an option, a new study is
being performed to gage the effectiveness of using dissolved oxygen in the reservoir to suppress
manganese levels. A crucial element of this study, especially in today’s political environment, is
to find the potential cost impact to the City of Barberton. The largest cost concern for this project
is the location of a proposed building to house the oxygenation equipment. Considerations
effecting location are the availability of three- phase electricity, access to the site, and noise
concerns for nearby residences. Keeping these three considerations in mind several pricing
options will be accumulated. At the conclusion of the study these price options will accompany
the results and recommendations and enable the City of Barberton to make a much more
informed decision regarding the future of their drinking water.
iv Barberton Reservoir Oxygenation Cost Estimate
Introduction: This project is to follow the preliminary design report “Barberton Reservoir
Oxygen Deficit Evaluation -Hypolimnetic Oxygenation Assessment” (see appendix C) which
concluded with strategies for solving the oxygen deficiency of the Barberton Reservoir in order
to suppress the manganese mobility from the sediments into the water. Phase 1 of the strategy
called for a system which could introduce dissolved oxygen into the deepest regions of the
reservoir. A rough cost estimate was included for this work which left many cost variables open.
The purpose of this project is to expand on that section by compiling cost estimates on necessary
site upgrades. Potential costs associated these site upgrades will have a direct impact on the
equipment choices for the larger project. Site work to be considered includes the availability of
electricity, access to the proposed site, and a potential building to house equipment.
Figure 1: Barberton Reservoir
Background: The Barberton reservoir covers 197 acres in Summit County, OH. The reservoir
feeds the Barberton Water Treatment Plant (WTP) at an average rate of 4.6 million gallons per
day (MGD). Recently, the WTP added membrane filters for final treatment of water, taking the
place of sand filters. Unknowingly, removing the sand filters meant removing the ability to filter
soluble manganese. Due to these changes in the treatment process at the WTP, soluble
manganese in the drinking water has become an issue. While excess amounts of manganese does
not pose any known health threats it does foul the taste of the water and can lead to decreased
efficiency in some of the treatment processes. For these reasons the City of Barberton has
commissioned a study to find effective ways of limiting the soluble manganese levels. The
subsequent study found that the best way to reduce the levels of manganese was not to
implement a new treatment process in the plant but to reduce the levels in the reservoir.
Manganese enters the lower water column from the sediments at the bottom of the reservoir.
Higher levels of manganese typically coincide with anoxic conditions, or a depletion of the
dissolved oxygen. To combat this, dissolved oxygen can be artificially introduced in the lower
water columns. The strategic introduction of dissolved oxygen has been shown to effectively
1 Barberton Reservoir Oxygenation Cost Estimate
reduce manganese concentrations in other reservoirs around the country. For additional
information about the preliminary design report or the background of this project, see appendix
C, page 3.
Previous Study Findings: The recommendations for Phase 1 of the Barberton Project called for
the oxygenation of the hypolimnetic layer. This is to be achieved by drawing water from the
reservoir, saturating this water with pure dissolved oxygen, and pumping the water through
piping into strategic hypolinetic regions of the reservoir. This process will require two
components. The first main component will be the oxygen source. The first option for the
oxygen source would be bulk liquid oxygen (LOx) which would be delivered by way of a semi
tanker and stored at an on-site storage tank. The second option would on-site generation from a
pressure swing absorption (PSA) system or vacuum swing absorption (VSA) system. The second
main component would be the oxygen saturation system which would include the saturator,
pump, piping, and controls. This component has many viable choices for equipment depending
mostly on the site conditions which will be examined in this project. For further findings within
the preliminary design report, see appendix C, page 15.
2 Barberton Reservoir Oxygenation Cost Estimate
Electrical/Power Considerations: The first step in estimating a cost for this project is to decide
which equipment to use. However, the biggest limiting factor in the decision is the available
supply and type of power. The first step is to determine whether single phase or three phase
power is available and which would be best to use in the current situation. The preliminary
design report (appendix C, page 15) states that 3 phase power is required for several equipment
options. According to “3phasepower.org”, three phase power is the preferred form of electricity
in motor driven industrial applications. Three phase power is transmitted as three alternating
currents of the same frequency but offset by 1/3 of a cycle or 120°. (See figure 2) By offsetting
each phase by one third, there is the effect of constant power. This “constant power” allows
large, high rpm motors run much more
smoothly and therefore longer than a similar
motor on single phase. Additionally, 3 phase
motors are often more compact and less costly
than single phase motors of the same voltage
class and rating. With this being said, single
phase is more economical when only small
loads are present such as in residential
instances. As it is not clear which option will
be most cost efficient, both will be considered.
Figure 2: Phase Diagram for 3 Phase
A site visit was performed with an employee of the Ohio Edison power company. Upon site
investigation it was found that a single phase line currently runs from Summit road to a metering
building built into the south side of the dam. This line ends about 225 feet short of the proposed
building location, but could easily be extended. Figure 3 shows an aerial view of the site with the
red line representing the current single phase line running from Summit road. It was also
determined that a three phase line
could be run from near Summit rd,
South of the dam, and up to the
proposed building site. Following a
conversation regarding the details
of the project, Ohio Edison agreed
to provide an estimated cost for
both options. According to law, the
City of Barberton will be required
to pay 40% of the cost to run 3
phase electricity to the site. The
estimated cost to the City would be
about $8,000 to run 3 phase to the
Figure 3: Current Overhead Electricity 3 Barberton Reservoir Oxygenation Cost Estimate
location of the current single phase pole at the reservoir. Additionally, the hired electrician would
be required to extend the electricity from the pole to the location of the equipment/building and
make any hookups. According to an area electrical company, the cost to bury an extension from
the pole to the site would be about $6-$8 per foot. Additionally, the cost to hook this electricity
into a breaker and into required equipment at the building or near the equipment would be
approximately $5,000-$6,000 for single phase and $9,000-$10,000 for 3 phase electricity. See
Table 1 for associated electricity costs.
4 Barberton Reservoir Oxygenation Cost Estimate
Site Access Considerations: Site access is also a large factor for this project. The first concern
for access is related to simply getting materials for the main road to the proposed site. Current
site access consists of an eight to ten foot wide dirt/gravel path through a wooded area. The
distance from the road to the site is approximately 1200 ft. This path is sufficient for small trucks
in dry weather. However, to accommodate the electric trucks, delivery trucks, concrete trucks,
etc. this path will need to be upgraded. See Figure 4 for approximate dimensions of concrete
trucks which will be used as an assumption for all large trucks. The path should be graveled and
widened to about 12 feet. First, minor tree trimming is needed to allow the large power truck to
gain access. Second, minor
excavation will need to be
performed to produce a flat drive.
Third, an aggregate base would
have to be added to make the site
accessible. The most stable
aggregate base would likely consist
of #3 & 4 limestone for a base in
soft spots and a 3-4” cap of #57
limestone. Also included is time for
a backhoe to assist in laying the
aggregate base. See Table 2 for
approximate costs related to access.
Figure 4: Approximate Concrete Truck Dimensions
5 Barberton Reservoir Oxygenation Cost Estimate
The second access concern for the site is related to the bulk liquid oxygen delivery. This would
require delivery of the bulk oxygen by tractor trailer. The first option would be to place the
storage tank on the west side of Summit Rd. Currently this is not an option, and would require
significant site clearing, earthwork and paving to be made an option. See Figure 5 for a view of
the current entrance to the reservoir from Summit Road.
Figure 5: Reservoir Entrance from Summit Rd
The second option would be to place an oxygen storage tank on the east side of Summit Rd near
Barberton Water Treatment Plant. This would solve the access problem but also be a significant
undertaking as the road would need to be closed and the pipe run would be a minimum of 1500 ft
depending on the location of the tank near the WTP. For these reasons on-site generation of
oxygen seems to be the easier choice. It would also be a much less permanent choice if the
equipment is to be experimental in its early stages.
6 Barberton Reservoir Oxygenation Cost Estimate
Cover Building Considerations: Currently, two options exist for preventing weather exposure
to the equipment. The first option is to utilize equipment with built in weather protection. Again,
this would be the easiest and least permanent choice. Problems with this choice include potential
noise restrictions and an open availability to the public. The second choice would be to build a
permanent structure of some kind to provide cover for the equipment. To help estimate building
cost RS Means estimating software was utilized. The Cost Works by RS Means allows the user
to specify many factors which will influence the cost of the project. For each option, Canton OH
was chosen as the nearest city, union rates were used for labor, and construction type was
considered commercial. The next option is to estimate by building type or by assemblies.
First, the building type option was utilized. The closest option to the desired building was a one
story warehouse. I was able to input the square footage, story height, cost quarter and a few
specific details. Based on the limited knowledge of equipment sizes at the current time and
restriction within the program, a 30 ft x 30 ft building with 12 ft high walls was chosen for
estimation. If the square footage of the building must change, the cost per square foot can still be
used to acquire an approximate total price. This option is quite easy to use because it makes
many assumptions for the user. The downside to this is a building to store oxygenation
equipment will inevitably be slightly different than a standard warehouse. However, there are
enough similarities between the two to get a quick ballpark estimate. The program gave an
estimate of approximately $46,000 or $51 per square foot. This value seemed high given some of
the features of a warehouse which are not necessarily needed in the application at Barberton.
However, the estimate was kept because it represents the cost of a well built, long lasting
building. See Table 3 for overview of estimate. See appendix A for detailed estimate.
Table 3: Warehouse Building Estimate 7 Barberton Reservoir Oxygenation Cost Estimate
The next option was the estimation by assembly which gives the user more control over exactly
which methods are used in the construction of the building. Each assembly, such as type of floor,
type of wall, type of roof, etc can be chosen separately. With more control, a smaller and simpler
building could be chosen to give a more accurate estimate of the minimum cost. For the second
estimate a 20ft x 20 ft building was chosen with 12 ft high walls. To start, a 6” cut and fill was
chosen to provide an aggregate base for the slab. A 6” thick light industrial, reinforced concrete
pad was used for the floor. The walls and roof are to be constructed of wood framing with metal
sheeting covering. There will be one 3ft x 6’-8” man door and one 12ft x 12 ft electric operated
garage door to facilitate equipment installation. The interior will be fully wired with switches,
receptacles, and lighting. See Table 4 below for a complete cost estimate. 3 phase wiring was
intentionally excluded from the building estimate as it is included in the associated electrical
costs. (See Table 1) The estimate also excludes insulation and heating. These could become
requirements if there are noise or temperature requirements associated with the future equipment.
This estimate represents the minimum cost to build a permanent structure which will adequately
house equipment. See appendix B for full scale estimate.
Table 4: Building Cost by Assembly 8 Barberton Reservoir Oxygenation Cost Estimate
Conclusion: The purpose of this project was to compile the costs associated with the various site
upgrades required for the oxygenation of the Barberton Reservoir. Site upgrades considered
where power availability, site access, and a potential building to house equipment. Based on the
information found in this report, most of the options brought forward in the preliminary design
report (appendix C, pg 15) will be available. The exception is bulk liquid oxygen delivery which
would require a significant cost to allow access to semi trailers. Estimated electrical upgrades
range from $7,350 to $19,800 depending on the type of electrical service desired. Access
upgrades to allow entrance by larger trucks should cost roughly $6,600. To put a building on the
site to house equipment would probably range from $20,000 to $50,000 depending on the desired
size and options. Based on these findings, the total cost to upgrade the site in preparation for the
oxygenation equipment ranges from $13,950 to $76,400. The final cost depends totally on which
options are chosen. See Table 5 below for all cost options.
9 Appendix A
10 Building Type:
Location:
Story Count:
Story Height
Square Foot Cost Estimate Report
Barberton Estimate 1
Warehouse with Concrete Block / Steel
Frame
CANTON, OH
1
12
Floor Area (S.F.):
Labor Type:
Basement:
Data Release:
Cost/ SF:
Building Cost:
900
Union
No
Year 2011 Quarter 1
$55.19
$49,672
Estimate Name:
A Substructure
A1030
A2010
B Shell
B1020
B2010
B2030
C Interiors
C3020
D Services
D2040
D3020
D4010
Costs are derived from a building model with basic components.
Scope differences and market conditions can cause costs to vary significantly.
Slab on Grade
Slab on grade, 5" thick, heavy industrial, reinforced
Basement Excavation
Excavate and fill, 30,000 SF, 4' deep, sand, gravel, or common
Roof Construction
Floor, steel joists, beams, 1.5" 22 ga metal deck, on columns,
Floor, steel joists, beams, 1.5" 22 ga metal deck, on columns,
Exterior Walls
Concrete block (CMU) wall, regular weight, 75% solid, 8 x 8 x 16,
Exterior Doors
Door, aluminum & glass, with transom, narrow stile, double door,
Door, steel 18 gauge, hollow metal, 1 door with frame, no label,
Door, steel 24 gauge, overhead, sectional, electric operator, 12'Floor Finishes
Concrete topping, hardeners, metallic additive, minimum
Concrete topping, hardeners, metallic additive, maximum
Vinyl, composition tile, maximum
Rain Water Drainage
Roof drain, steel galv sch 40 grooved, 5" diam piping, 10' high
Roof drain, steel galv sch 40 threaded, 5" diam piping, for each
Heat Generating Systems
Warehouse ventilization with heat system 24,000 CFM Supply
Sprinklers
Wet pipe sprinkler systems, grooved steel, ordinary hazard, 1
Cost Per
S.F.
$11.96
$11.53
$0.43
$16.32
$7.94
$5.88
$2.50
$1.82
$1.82
$19.96
$1.41
$3.12
$3.06
Cost
$10,764
$10,377
$0
$387
$0
$14,688
$7,146
$0
$0
$5,292
$0
$2,250
$0
$0
$0
$1,638
$1,638
$0
$0
$0
$17,964
$1,269
$0
$0
$2,808
$0
$2,754
$0
D5010
Electrical Service/Distribution
$1.59
D5020
Service installation, includes breakers, metering, 20' conduit &
Feeder installation 600 V, including RGS conduit and XHHW
Switchgear installation, incl switchboard, panels & circuit breaker,
Lighting and Branch Wiring
$5.41
D5030
Receptacles incl plate, box, conduit, wire, 5 per 1000 SF, .6
Wall switches, 1.0 per 1000 SF
Miscellaneous power, to .5 watts
Central air conditioning power, 3 watts
Fluorescent fixtures recess mounted in ceiling, 0.8 watt per SF,
Fluorescent fixtures recess mounted in ceiling, 2.4 watt per SF,
Communications and Security
$5.37
Communication and alarm systems, fire detection, addressable,
Fire alarm command center, addressable without voice, excl.
0.00%
F Special Construction
0.00%
G Building Sitework
SubTotal
Contractor Fees (General Conditions,Overhead,Profit)
Architectural Fees
User Fees
Total Building Cost
100%
5.00%
5.00%
0.00%
$0.00
$0.00
$50.06
$2.50
$2.63
$0.00
$55.19
$1,431
$0
$0
$0
$4,869
$0
$0
$0
$0
$0
$0
$4,833
$0
$0
$0
$0
$0
$0
$45,054
$2,253
$2,365
$0
$49,672
Appendix B
13 Barberton Option 4
Labor Type: Standard Union
Location: Canton OH 446-447
Data Release :Year 2011 Quarter 1
Quantity
400
400
960
1
1
400
400
400
400
36
Description
Slab on grade, 6" thick, light industrial,
reinforced
Unit
S.F.
$
3.69
$
3.42
$
7.11
$ 1,476.00
$
1,368.00
$
2,844.00
$
1.06
$
1.14
$
2.20
$
424.00
$
456.00
$
880.00
$
3.62
$
3.32
$
6.94
$ 3,475.20
$
3,187.20
$
6,662.40
$ 310.05
$
65.53
$
375.58
$
310.05
$
65.53
$
375.58
$3,696.75
$ 841.96
$
4,538.71
$ 3,696.75
$
841.96
$
4,538.71
$
1.82
$
1.66
$
3.48
$
728.00
$
664.00
$
1,392.00
$
0.69
$
2.74
$
3.43
$
276.00
$
1,096.00
$
1,372.00
$
0.13
$
0.45
$
0.58
$
52.00
$
180.00
$
232.00
$
2.69
$
5.03
$
7.72
$ 1,076.00
$
2,012.00
$
3,088.00
$
4.81
$
4.81
$
$
173.16
$
173.16
Wood roof, flat rafter, 2" x 6", 16" O.C.
S.F.
Metal siding, aluminum panel,
corrugated, .032" thick, painted
S.F.
Door, aluminum, combination, storm &
screen, hinged, 3'-0" x 6'-8" opening
Opng.
Door, aluminum & fiberglass, overhead,
heavy duty, electric operator, 12'-0" x 12'0" opening
Opng.
Roofing, corrugated, aluminum, painted,
.0215" thick, .344 PSF
S.F.
Receptacles and wall switches, 400 SF,
8 receptacles
l
S.F.
SF
Receptacles and wall switches, 400 SF,
1 switch
S.F.
Fluorescent fixtures, type A, 8 fixtures
per 400 SF
S.F.
Gravel cut and fill, 80 HP dozer and
roller compactor, 50' haul, 6" lift, 2
passes
C.Y.
$
-
Installation
O&P
Ext.
Ext. Material Installation
O&P
O&P
Material
O&P
Total O&P
-
Total
Ext. Total
O&P
$ 21,557.85
Appendix C
15 DRAFT Preliminary Design Report
Barberton Reservoir Oxygen
Deficit Evaluation Hypolimnetic Oxygenation
Assessment
Prepared for
City of Barberton
December 16, 2010
Prepared in partnership with
Christopher M. Miller, Ph.D., PE
Associate Professor – University of Akron
Department of Civil Engineering
210 ASEC
Akron, OH 44325-3905
Prepared by
Gantzer Water Resources Engineering, LLC
14816 119th PL NE
Kirkland, WA 98034
Barberton Reservoir Oxygen Deficit Evaluation - Hypolimnetic Oxygenation Assessment
Introduction
The purpose of this study is to estimate the oxygen deficit in Barberton Reservoir with
regards to release and subsequent mobility of soluble manganese (Mn) from the sediments to the
overlying water column. Additionally, this study will provide a recommendation of how
hypolimnetic oxygenation of Barberton Reservoir could meet oxygen deficiencies during the
year with the main focus of suppressing Mn mobility from the sediment. This study includes
defining the design criteria and recommendations for the following:
Task 1 and 2 are outlined as follows:
1. Perform process sizing calculations using existing data to estimate a total hypolimnetic
oxygen demand (HOD) design specification. This scope assumes that the HOD is a
combination of sediment oxygen demand (SOD) and water column oxygen demand
(WOD). Elements of this analysis include:
a. Dissolved oxygen loss in the hypolimnion.
b. Water column oxygen demand.
c. Apply appropriate safety factors to calculated HOD (predict diffuser induced
oxygen demand (DIOD).
d. Estimate SolarBee impact on DO demand and thermal stability.
e. Evaluate historical oxygen demand calculations and compare to observed oxygen
conditions.
f. Assist University of Akron sampling studies
i. Develop and implement a comprehensive sampling strategy.
ii. Review and analyze CTD profiles.
iii. Compare to historical data calculations to establish a current baseline
oxygen demand for system design.
g. Evaluate groundwater inputs
i. Review historical groundwater pumping strategies.
ii. Determine groundwater impact on reservoir water quality.
iii. Calculate the oxygen deficit in the groundwater to determine design
capacity and corresponding oxygen input criteria.
iv. Provide guidance/feedback for the intake structure retrofit to optimize
mixing and distribution of oxygenated groundwater.
h. Evaluate water column profiles with the oxygen plume model to determine:
i. Estimated oxygen transfer efficiency.
ii. Thermal stability to adequately size a destratification system.
iii. Design capacity and corresponding oxygen input criteria for reservoir
HOD.
iv. Establish a working hypolimnion volume for predictive oxygen demand
calculations.
i. Consolidate the water column profile data in surfer (3-D graphing) for review and
evaluation.
2. Conduct a process mechanical sizing study for number, position, and length of diffusers.
Establish the required pure oxygen flow rate and delivery pressure.
2
Barberton Reservoir Oxygen Deficit Evaluation - Hypolimnetic Oxygenation Assessment
a. Use the plume model to determine appropriate diffuser length, depth, and flux rate
to optimize oxygen input to the bottom waters.
b. Establish oxygen supply sizing, e.g. pressure swing adsorption (PSA) delivery
capacity or bulk liquid oxygen (LOx) storage capacity for reservoir and
groundwater systems.
Background
Barberton reservoir is a 196-acre reservoir in Norton Township, and is the only lake in
Summit County used for water supply. It was observed to be eutrophic and polymictic with an
approximate volume of 877 MG and a maximum depth of approximately 23 feet near the dam.
The Barberton water treatment plant (WTP) uses traditional water treatment techniques; pretreatment, coagulation, flocculation, sedimentation, filtration, and chlorination to treat water for
distribution. The WTP has a maximum plant capacity of 8 MGD and averages 4.6 MGD.
In August 2003, two SolarBee units (SB10000) were installed as a water quality
management strategy with the following objective: “to improve the water quality of Barberton
Reservoir, prevent blue-green algae blooms, and alleviate taste, odor, and stratification
problems” (http://lakes.solarbee.com/siis/location/167). In February 2006, the two SB10000
units were removed and replaced with four units (SB10000U-55). Per an email correspondence
from Michael Christensen, the intakes to the SB10000U-55 units were raised from ten feet below
the surface to seven feet in 2009.
Recently, the WTP replaced sand filters with newer membrane technology in an effort to
combat disinfectant by-product (DBP) formation as well as challenges related to
cryptosporidium removal. However, in doing so, the WTP was unaware of the significance of
the manganese (Mn) removal capacity of the sand filters. Traditionally, soluble Mn can be
removed through pre-treatment using chemicals such as potassium permanganate or chlorine
dioxide; however, this strategy has limitations.
Dissolved metals such as iron (Fe) and manganese (Mn) are commonly found in water
supply reservoirs as a result of transport from the sediments (Hoffmann and Eisenreich, 1981;
Balzer, 1982; Zaw and Chiswell, 1999). Increased levels of these dissolved metals usually
coincide with anoxic conditions in the hypolimnion during thermal stratification in the summer
(Yagi, 1996; Wann et al., 1997). Despite effective removal of dissolved metals in the treatment
process, recent studies have shown that Mn can re-dissolve in sedimentation basins due to the
formation of anoxic conditions in the settled sludge (Budd et al., 2007). If the source water
could be managed in such a way as to minimize the availability of iron and manganese, redissolution during the treatment process would be avoided.
EPA regulations categorize Fe and Mn as aesthetic contaminants. Although health risks
have not been associated with either of these metals, elevated levels of either Fe or Mn often
result in customer complaints. A secondary maximum contaminant level (SMCL) of 0.3 and
0.05 mg l-1 has therefore been established for dissolved Fe and Mn, respectively. Additionally,
soluble Mn has been observed to cause fouling of membrane filters, thus reducing their filtering
capacity thus increasing maintenance and servicing.
To address hypolimnetic anoxia and the subsequent mobilization of dissolved Fe and Mn
to the bulk water, oxygenation of bottom waters was identified as a very successful management
strategy. Following the installation of an oxygenation system in Carvin’s Cove Reservoir (CCR)
in Roanoke, Va., and operated without interruption, the oxygenation system was able to reduce
3
Barberton Reservoir Oxygen Deficit Evaluation - Hypolimnetic Oxygenation Assessment
the bulk average hypolimnion soluble Mn concentration by up to 97% (Gantzer el al., 2009a).
Similar results have been observed at other water-supply reservoirs such as Spring Hollow
Reservoir, in Roanoke, Va. and Crystal Reservoir in Cheyenne, Wyoming, where soluble Mn
concentrations have consistently been maintained below the EPA SMCL as a result of DO
maintenance.
Barberton 2010 Data Review
After reviewing the 2010 water quality data from high resolution profiles collected by the
University of Akron at five locations along Barberton Reservoir , it is clear that the reservoir
exhibits stable thermal stratification coupled with severe anoxia early in the summer that persist
for approximately five months (April – September). Appendix A shows a map of profiling
locations and summarizes data collection using the SeaBird Electronics SBE 19PlusV2 (CTD).
Appendix B summarizes all the CTD data collected during 2010. Despite the stable thermal
stratification throughout the summer, mixing events were hypothesized based on observed spikes
in the Mn and DO data (see Figure 1). Rogue mixing events create a potential threat to water
quality, especially once Mn levels increase in the bottom waters. Additionally, once the
reservoir begins to destratify in the late summer and early fall, wind-induced mixing was
observed to dramatically affect the bottom waters, which was observed in the CTD data collected
between August 17 through September 21 (Appendix B). Thermal stratification was observed in
late April, with an approximate 2.8ºC temperature differential that increased to over 13 ºC by late
July. Dissolved oxygen (DO) conditions were observed to deteriorate very rapidly following the
onset of thermal stratification. Review of the water quality grab samples for Mn revealed a
steady increase in soluble Mn from the ‘benthic’ sample depth.
Manganese data were collected at three depths, (surface, intermediate, and benthic)
throughout the year at several locations along the reservoir and are summarized in Figure 1.
Additional samples were collected in August and September to identify distribution of Mn
throughout the water column (Figure 2) as well as potential sources of soluble Mn to the bulk
water. Review of the Mn data showed very low concentrations at the far end of the reservoir
(0.043 mg/l) and in headwaters (0.009 mg/l). Additionally, Mn concentrations in water over
sediments at upstream locations (site 2) were elevated (2.23 mg/l max), but the highest
concentrations of soluble Mn (7.1 mg/l) were observed in the deepest sections (site 5) of the lake,
(Figure 1). Figure 3 summarizes all the Mn data, which is plotted against DO. The plot shows
the relationship between DO and soluble Mn and is separated into two colors, red when the Mn
concentrations were observed above the EPA SMCL and blue when Mn concentrations were
below the EPA SMCL. From this data, it is observed that adequate maintenance of DO (e.g. > 6
– 8 mg/l) results in soluble Mn concentrations maintained below 0.05 mg/l. Review of the Mn
data reveals that the primary source of soluble Mn to the water column comes from the bottom
waters in the deepest regions of the reservoir.
Manganese concentrations collected at the treatment plant were analyzed with the water
column Mn data collected during 2010, and is summarized in Figure 4. Figure 4 shows Mn
concentrations collected at the benthic elevation at site 5 along with the treatment plant Mn
concentrations. During early May and late August, Mn concentrations from the benthic location
were observed to decrease dramatically, from 2 and 7 mg/l respectively to ~ 0.02 mg/l.
Coincidentally, during this same time period, Mn concentrations at the plant were observed to
increase substantially, from 0.07 to 0.16 and 0.35 mg/l for May and August respectively. It
4
Barberton Reservoir Oxygen Deficit Evaluation - Hypolimnetic Oxygenation Assessment
should be noted that groundwater pump operation did not occur until August 31; therefore, the
wells did not have any impact on the Mn concentrations observed in the plant during these two
examples. A simple mass balance of Mn during the May example reveals that approximately
0.54 kg of Mn was observed in the benthic region, which assumes a corresponding volume for
this small region of 67 MG, which is the estimated volume for the bottom two – three feet of the
reservoir. The resulting mass calculation, assuming the entire reservoir volume (877 MG) with
the observed raw water concentration of 0.163 mg/l, was calculated also to be approximately 0.5
kg. The mixing event in August was observed to be a result of the destratification process that
occurs each fall. Figure 4 shows two arrows that identify when destratification was observed to
start and when the lake was observed to be destratified. The summary images during August,
presented in the Appendix, support the destratification observation. As the bottom waters were
mixed with the surface, Mn concentrations in the plant were observed to increase
simultaneously. A mass balance during August reveals 1.89 kg of Mn in the benthic region and
a corresponding 1.2 kg of Mn in the surface waters following fall turnover. Both these examples
along with the mass balances shows that elevated Mn concentrations at the bottom are the cause
of the increased Mn concentrations observed in the plant.
Barberton Reservoir exhibits a very common problem that plagues the water-supply
industry; how to manage elevated soluble Mn concentrations in source water. This is based on
the observations of stable thermal stratification, rapid and persistent hypolimnetic anoxia, and
mobilization of soluble Mn from the sediments resulting in very high levels of soluble Mn in the
bottom waters. The fact that Barberton Reservoir is shallow only exacerbates the problem,
making water quality susceptible to natural conditions that promote intermittent mixing. Despite
the challenges in and on the reservoir, a common strategy to oxygenate the bottom waters has
been identified as a cost effective sustainable source-water management strategy. Therefore the
following oxygenation design and management strategy is recommended for Barberton
Reservoir. The proposed management strategy is divided into three stages;
1. Phase 1: Replenish oxygen deficiency. Install an oxygenation system that meets
the estimated oxygen demand.
2. Phase 2 (Monitor / Evaluate): Monitor oxygen conditions, lake response and
evaluate reservoir response to Phase 1.
3. Phase 3, (only necessary if Phase 1 is not successful), evaluate the stability of
thermal stratification and address promoting complete reservoir mixing using a
destratification diffuser.
Phase 1 would use a side-stream super-saturation (SSS) oxygenation system that would
withdraw water from the hypolimnion, pass it through an oxygenation chamber where pure
oxygen gas would be injected to increase the DO concentration to saturation conditions at
pressure, and then distribute the oxygen saturated water back to the hypolimnion. Phase 2 would
be a minimum of one year to monitor and operate the SSS and corresponding water column
response. This time period would be used to provide feedback to system operation to improve
efficiency and effectiveness. An evaluation period would complete phase 2 and move to phase 3
or continue to operate as outlined during the monitoring/evaluation period. Phase 3 would be the
design and installation of a destratification system that can input enough energy to maintain the
water column isothermal, thus promoting greater penetration of oxygen into the sediment. Both
the SSS and the destratification system would be operated together to meet the water quality
goals outlined by the Barberton staff.
5
8.15
2.75
7.15
2.25
Manganese, Mn (mg/l) _
Manganese, Mn (mg/l) _
6.15
5.15
4.15
3.15
2.15
1.75
1.25
0.75
1.15
0.15
0.25
0.125
0.2
0.1
0.15
0.075
0.1
0.05
0.05
0.025
0
23-Mar
14.0
0
22-Apr
23-May
22-Jun
23-Jul
22-Aug
22-Sep
22-Oct
22-Nov
23-Mar
12.0
23-May
22-Jun
22-Apr
23-May
22-Jun
23-Jul
22-Aug
22-Sep
22-Oct
22-Nov
23-Jul
22-Aug
22-Sep
22-Oct
22-Nov
10.0
Dissolved Oxygen (mg/l)_
Dissolved Oxygen (mg/l)_
12.0
22-Apr
10.0
8.0
6.0
4.0
8.0
6.0
4.0
2.0
2.0
0.0
0.0
23-Mar
22-Apr
23-May
22-Jun
23-Jul
22-Aug
22-Sep
22-Oct
22-Nov
23-Mar
Date (Year)
Date (2010)
Surface (303.7 m msl)
Intermediate (301.2 m msl)
Bottom (299.2 m msl)
Surface (303.7 m msl)
Intermediate (301.8 m msl)
Bottom (300.9 m msl)
Figure 1. Soluble Mn concentrations and corresponding DO collected at three different depths (surface, intermediate, and benthic) for
Sites 5 (left) and 2 (right). Both sites show elevated levels of soluble Mn from the benthic samples, with observed concentrations at
site 5 significantly higher than observations at site 2.
305.0
305.0
304.0
304.0
303.0
303.0
302.0
302.0
301.0
301.0
300.0
300.0
299.0
299.0
298.0
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0 0.0
2.0
Manganese, Mn (mg/l)
10-Aug
17-Aug
24-Aug
14-Sep
4.0
6.0
8.0
10.0
298.0
14.0
12.0
Dissolved Oxygen, DO (mg/l)
Intake (6')
Intake (13')
10-Aug
17-Aug
24-Aug
14-Sep
Intake (6')
Intake (13')
Figure 2. Soluble Mn profiles (left) and corresponding DO profiles (right) collected during August and September at Site 5.
7
Elevation (m msl)_
Elevation (m msl)_
Barberton Reservoir Oxygen Deficit Evaluation - Hypolimnetic Oxygenation Assessment
8.0
Manganese, Mn (mg/l) _
7.0
6.0
5.0
4.0
3.0
2.0
1.0
0.0
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
Dissolved Oxygen (mg/l)
Reservoir Mn concentrations < smcl
Reservoir Mn concentrations > smcl
Figure 3. Soluble Mn versus DO data collected in Barberton Reservoir during 2010 summer
stratification showing the correlation of elevated Mn corresponding to low DO. Red and blue
represent Mn concentrations above and below the EPA SMCL of 0.05 mg/l respectively.
2
0.15
1.5
0.1
1
0.05
0
7-Apr
0.5
0
21-Apr
5-May
19-May
Date (2010)
Intake Total Mn Concentration
Manganese Concentration (mg/l)_
0.2
0.4
8
Well pump operation
0.3
6
0.2
4
0.1
2
0
1-Jul
Manganese Concentration (mg/l)_
2.5
Manganese Concentration (mg/l) _
Manganese Concentration (mg/l) _
0.25
0
1-Aug
1-Sep
1-Oct
1-Nov
Date (2010)
Site 5 Benthic Sample Depth
Destrat Observed to Begin
Reservoir Destratified
Figure 4. Intake Mn concentrations plotted with site 5 benthic sample data showing increased plant concentrations and simultaneous
decreased benthic concentrations during spring (left) and fall (right). The box over the fall data indicates the timing of well pump
operation. Plant intake scale corresponds to the left axis and benthic samples with the right.
Hypolimnetic Oxygen Demand
1. Perform process sizing calculations using existing data to estimate a total hypolimnetic
oxygen demand (HOD) design specification.
a. Dissolved oxygen loss in the hypolimnion: The design hypolimnetic oxygen
demand (HOD) is the key design parameter necessary to size an oxygenation
system. The oxygen demand was calculated using a regression method of oxygen
content over time during the linear portion of the observed oxygen depletion
(Gantzer et al., 2009b). Data collected by University of Akron (UA) were used to
determine hypolimnion boundaries, hypolimnion volumes, oxygen content and
subsequently oxygen demand.
b. Water column oxygen demand: The April - June data were used to evaluate the
five locations along the reservoir with the lake volume being split proportionately
between each section.
c. Apply appropriate safety factors to calculated HOD (predict diffuser induced
oxygen demand (DIOD). The sum of the observed oxygen demand was then
multiplied by a safety factor of 1.2. The results of these calculations are:
Hypolimnion
Elevation
(ft msl)
Hypolimnion
Volume
(MG)
Average oxygen
depeltion rate
(mg/l/day)
HOD
DIOD
(kg/day)
1.2
Design oxygen
flow rate
(SCFM)
987
387
0.32
469
563
10
d. Estimate SolarBee impact on DO demand and thermal stability. The SolarBee
operation do not appear to have any impact on DO demand or thermal
stratification in that the inlet to each unit is positioned seven feet below the
surface at elevation 302 m (991 ft) msl.
e. Evaluate groundwater inputs.
i. Review historical groundwater pumping strategies. Groundwater pumping
appears to be applied during late summer and appears to be operated
minimally.
ii. Determine groundwater impact on reservoir water quality. The Mn levels
at the plant intake were reviewed and compared with the groundwater
pumping operations for 2009 and 2010. During all periods of groundwater
pumping operations elevated levels of Mn were observed in the raw water
intake. Figure 5 shows a summary of 2009 and 2010 intake Mn
concentrations. Review of this data shows that Mn concentrations were
observed to be doubled during all periods of groundwater pumping.
Manganese concentrations were observed to increase from ~ 0.1 mg/l
before pumps were turned on to over 0.2 mg/l during groundwater
pumping operations, then return to ~ 0.1 mg/l as soon as the groundwater
pumps were turned off (Figure 5).
Barberton Reservoir Oxygen Deficit Evaluation - Hypolimnetic Oxygenation Assessment
Manganese Concentration (mg/l)_
0.30
0.25
0.20
0.15
0.10
0.05
0.00
7-Oct
14-Oct
21-Oct
28-Oct
4-Nov
11-Nov
Date (2009)
0.4
Manganese Concentration (mg/l)_
0.35
0.3
0.25
0.2
0.15
0.1
0.05
0
1-Aug
15-Aug
29-Aug
12-Sep
26-Sep
10-Oct
24-Oct
Date (2010)
Intake Mn Concentration
Wells ON
Wells OFF
Figure 5. Intake Mn concentrations and groundwater pumping operations for 2009 and 2010
showing increases in raw water Mn simultaneous with pumping.
iii. Calculate the oxygen deficit in the groundwater to determine design
capacity and corresponding oxygen input criteria. Since groundwater
pumps are operated for only short periods of time, the system design was
increased only slightly to handle this potential input of low DO water. It
is recommended to increase oxygenation prior to operating the
groundwater pumps in forecast of the low DO during the short periods of
operation. This strategy is based on the ability of the reservoir to be
maintained with high enough DO that any inputs from pump operation are
easily buffered by the water quality maintained in the hypolimnion.
iv. Provide guidance/feedback for the intake structure retrofit to optimize
mixing and distribution of oxygenated groundwater. Because operation of
the groundwater pumps has been observed to have a direct impact on the
Mn concentrations in the raw water at the elevation of the intake is
recommended to relocate the discharge header of the groundwater to the
11
Barberton Reservoir Oxygen Deficit Evaluation - Hypolimnetic Oxygenation Assessment
region past sample site 5. This would require moving the outlet past the
initial deep basin near the dam to a location approximately 500 – 600 ft
upstream from the dam. It would also be recommended to have the
discharge be positioned three feet above the bottom and discharged
through a “T” parallel to the centerline of the reservoir. The objective of
this location and discharge is to:
1. facilitate more uniform mixing of the groundwater with the
surrounding oxygenated hypolimnion water
2. minimize perturbation of sediments, and
3. minimize mixing of the groundwater to elevations that would
impact the intakes.
Site 3
Recommended
location for
groundwater
discharge
Site 4
Site 5
-81.63
-81.62
-81.62
-81.62
-81.62
Figure 6. Topographical map of reservoir showing the proposed location of
groundwater discharge.
12
Barberton Reservoir Oxygen Deficit Evaluation - Hypolimnetic Oxygenation Assessment
f. Evaluate water column profiles with the oxygen plume model. The Plume Model
was used to identify the required flow rate to destratify the reservoir for a range of
temperature differentials observed between the epilimnion and hypolimnion. It
was determined that if the temperature differential can be maintained below 3 ºC,
then a 200 cfm compressor would be sufficient to maintain the water column
completely mixed. :
g. Consolidate the water column profile data in surfer (3-D graphing) for review and
evaluation, see Appendix B.
Oxygen Delivery System
Supersaturation design
The purpose of the oxygenation system is to inject oxygen (oxygenated water) into the deepest
region of the reservoir. This is proposed for the following reasons:
• Maintain elevated oxygen conditions near the sediment to satisfy historical
oxygen debt.
• Maintain the oxic/anoxic boundary below the sediment-water interface to mitigate
mobilization of soluble metals (Fe, Mn, PO4) from the sediment.
• Increase the overall water quality to enable operation of the middle intakes for
more diverse water quality options.
2. Conduct a process mechanical sizing study for number, position, and length of diffusers.
The oxygen demand was estimated to be 500 kg/day and was predicted to encompass the
water volume below 300.8 m (987 ft) msl. This would require an oxygen flow rate of 10
SCFM. The required delivery pressure depends on the final design of the saturation
system, which varies depending on the system or company chosen. In general operating
pressure can range from 40 – 110 psi. The required flow rate will also be dependent on
the operating pressure and corresponding saturation conditions that can be achieved.
Flow rates for the 40 – 110 psi range are estimated to be 1000 to 500 gpm respectively.
Final design would be established once the saturation design is approved.
a. Establish oxygen supply sizing. The proposed layout of the oxygenation system
is presented in Figure 7. The distribution system should enable injection of
oxygenated water along the deepest regions of the reservoir. Based on the current
topographical data, the oxygen would be most effective if distributed evenly in
the locations shown in Figure 7 as dotted lines. The oxygen supply is
recommended to provide sufficient reserves to maintain the 10 SCFM design flow
rate with the ability to increase flow to 15 SCFM for short periods. The increased
flow provides the ability to make up for oxygen loss caused by unpredicted
perturbations.
13
Barberton Reservoir Oxygen Deficit Evaluation - Hypolimnetic Oxygenation Assessment
Site 3
Site 4
Site 5
-81.63
-81.62
-81.62
-81.62
-81.62
Figure 7. Proposed layout of oxygenation distribution header, showing 150 to 200 ft lengths
(dotted lines) over the deepest sections.
14
Barberton Reservoir Oxygen Deficit Evaluation - Hypolimnetic Oxygenation Assessment
Phase 1 (Oxygenation) and Phase 2 (Monitoring) Cost Estimates
The following information summarizes cost estimate to install and operate the proposed
oxygenation system.
1. There are two main components for the SSS, the oxygen supply and the saturation
system.
a. The oxygen supply can be either bulk liquid oxygen (LOx) or on-site generation
from pressure swing adsorption (PSA) or vacuum swing adsorption (VSA). Both
systems have advantages and disadvantages and would need to be evaluated in
greater detail during the formal design phase of the project. LOx systems can be
purchased outright or leased, whereas on-site generation systems generally require
a capital investment.
b. There are several options for the saturation and subsequent discharge header for
the SSS. An example of estimated pricing from one company is provided.
2. Site upgrades were estimated. Site upgrades are dependant on the type of oxygen supply.
It is understood that the site would require 3 Phase AC upgrade in order to operate the
pump for the SSS. If on site generation were chosen as the oxygen source, then electrical
upgrades would require appropriate sizing to operate the feed air compressor as well.
3. Annual operating costs are based on the estimated oxygen cost (electrical for on site
generation or LOx product cost) and the proposed electrical cost to operate a 50
horsepower pump for the SSS. Electrical costs are based on $0.08/kW-hr.
4. Proposed monitoring would be provided by GWRE, LLC and would include all
equipment as well as technical support for system operation for the duration of the
contract. A formal quote would be provided during the design phase. The cost estimate
covers the essentials to monitor the system to allow sufficient feedback to operate the
SSS more effectively.
Oxygen supply
Oxygen saturator
Saturator, pump, piping and controls:
Site Upgrades
Oxygen pad (LOx tank):
Electrical (Upgrade to 3-phase 460 V)
$0 - $150,000
$178,000
$10,000 - $15,000
$??
Annual operating cost estimates:
Oxygen cost
$10,000 - 15,000 / yr
Saturator (60 Hp pump, 24 hours/day, 180days/yr):
$17,500 / yr
LOx tank lease ($2250/mo):
Monitoring / system operational support
15
$27,000 / yr
$10,000 / yr
Barberton Reservoir Oxygen Deficit Evaluation - Hypolimnetic Oxygenation Assessment
Destratification design
Recommended Strategy (Phase 3): promote destratification (complete mixing) of the water
column to facilitate uniform water quality.
•
•
•
•
Induce turbulence to disrupt algal growth, by cycling algae below photic zone
Create uniform water quality to enable the reservoir to perform more as a CSTR,
using the entire volume as a buffer from perturbations caused by storms and runoff.
Dilute any soluble constituents that enter the water column from upstream sediments.
Improve the overall water quality to enable operation of the second intake elevation
for more diverse operating capabilities.
The destrat system design is based on plume model results for various different thermal
conditions observed during the 2010 water column profiling. The proposed system is designed
to enable mixing of the total reservoir volume during a 24 – 36 hour time period. The plume
model was used to determine the estimated flow, which was based on 1/3 plume height of the
rising bubble-water mixture. This conservative measure would ensure adequate mixing is
induced to facilitate maintenance of isothermal conditions, which in turn would aid in
distribution of oxygen input from the SSS to sediments further away from the SSS injection.
The proposed destrat system layout is presented in Figure 8.
The destrat system would consist of a two pipe system with a porous hose diffuser system
spaced intermittently along the length. The two pipe system allows for air supply to be applied
to a ‘floater’ pipe to raise the system for maintenance and an air supply applied to the ‘supply’
pipe to provide air to the diffusers. The diffuser pipe would be constructed of porous hose and
would be spaced in 90 ft increments along the length of the system. The proposed system is
approximately 3500 ft long and would have diffuser sections placed every other 90 ft. Orifices
spaced along each active section of diffuser would allow for controlled air flow through each
section, thus increasing the robust performance of the system. Formal design specifications will
be provided if and when this phase of the project is executed.
16
Barberton Reservoir Oxygen Deficit Evaluation - Hypolimnetic Oxygenation Assessment
Site 3
Site 4
Site 5
Figure 8. Proposed layout of destratification system and oxygenation distribution header. The
yellow line represents the length and position of the destratification system.
17
Barberton Reservoir Oxygen Deficit Evaluation - Hypolimnetic Oxygenation Assessment
Phase 3 (Destratification) Cost Estimates
The following information summarizes cost estimate to install and operate the proposed
destratification system.
1. There are two main components for the destrat system, the air supply and the diffuser
header.
2. Annual operating costs are based on the estimated electrical cost to operate the
compressor, which is estimated to be 50 Hp. Electrical costs are based on $0.08/kW-hr.
3. Proposed monitoring would be provided by GWRE, LLC and would include all
equipment as well as technical support for system operation for the duration of the
contract. A formal quote would be provided during the design phase. The cost estimate
covers the essentials to monitor the system to allow sufficient feedback to operate the
destrat system more effectively.
Destratification Equipment
Air Source: 200 cfm, 50 Hp, Variable Speed Rotary Screw Air Compressor $26,500
Diffuser Piping: 500 ft supply, 3600ft diffuser header, 1800 ft of diffuser $290,000
Annual operating cost estimates:
Destrat Compressor: 50 Hp (12 hours/day, 180 days/yr)
Monitoring / system operational support
$8,000 / yr
$5,000 / yr
Summary
Barberton reservoir is a textbook example of anoxia, geochemical focusing, solubilization
and subsequent mobilization of Mn from the sediments to the overlying waters, ultimately
leading to water quality problems related to elevated Mn in the raw water. Oxygenation has
been identified as a very reliable method to manage anoxia and subsequently prevent
mobilization of Mn. The following strategies are therefore recommended:
1. Focus 2011 monitoring on data collection during April – June to capture the regression
period of DO depletion. This will enable confirmation / evaluation of the DO demand
and system sizing, which can be used for the design portion of Phase 1. Continue to
monitor oxygen and Mn conditions in the source water to build on the data collected
during 2010.
2. Inject oxygenated water into the deepest regions of the reservoir through the use of a
super-saturation oxygenation system (SSS).
3. Consider moving the discharge pipe for the groundwater ~ 500 – 600 ft upstream of the
dam and have the water discharged three ft above the bottom from a “T” that is parallel
with the centerline of the reservoir.
4. Following installation of the SSS, monitor the bottom waters continuously with a remote
DO sensor while continuing to collect water column profiles as well as Mn data
throughout the reservoir.
5. Use the first year of oxygenation to evaluate the overall water quality and reservoir
response to oxygenation.
6. Evaluate the long-term goal of the reservoir and potential need if necessary to mitigate
18
Barberton Reservoir Oxygen Deficit Evaluation - Hypolimnetic Oxygenation Assessment
thermal stratification with a destratification system designed to maintain isothermal
conditions year round.
This report is based upon the data and information available at the time of composition.
The author reserves the right to modify, change or develop new conclusions when and if
additional information and data is forthcoming. Please call (206.999.1878) or write
([email protected]) if there are other questions.
Sincerely,
Paul A. Gantzer, Ph.D., P.E.
President
Gantzer Water Resources Engineering, LLC
19
Barberton Reservoir Oxygen Deficit Evaluation - Hypolimnetic Oxygenation Assessment
References
Balzer, Wolfgang (1982). “On the Distribution of Iron and Manganese at the Sediment/Water
Interface: Thermodynamic Versus Kinetic Control.” Geochimica et Cosmochimica Acta,
46, pp. 1153-1161.
Budd, George, Knocke, William, Hanchak, John, Rice, Craig, and Billman, Mellisa (2007).
“Manganese Control Issues with Changing Treatment Sequences – Need for
Understanding Manganese and Related Profile in a Plant.” VWEA & VA-AWWA JOINT
ANNUAL MEETING WATER JAM 2007, September 16-20, pp. all.
Gantzer, P. A., L. D. Bryant, and J. C. Little. 2009a. Controlling soluble iron and manganese in a
water-supply reservoir using hypolimnetic oxygenation. Water Res. 43: 1285-1294.
Gantzer, P. A., L. D. Bryant, and J. C. Little. 2009b. Effect of hypolimnetic oxygenation on
oxygen depletion rates in two water-supply reservoirs. Water Res. 43:1700-1710.
Hoffmann, Michael R. and Eisenreich, Steven J. (1981). “Development of a ComputerGenerated Equilibrium Model for the Variation of iron and Manganese in the
Hypolimnion of Lake Mendota.” American Chemical Society, 15 (3), pp. 339-344.
Wann, J.K., Chen, C.T.A., and Wang, B.J. (1997). “A Seasonally Anoxic Mountain Lake and
Active Fe Cycle in Tropical Taiwan.” Aquatic Geochemistry, 3, pp. 21-42.
Yagi, Akihiko (1996). “Manganese Flux Associated with Dissolved and Suspended Manganese
Forms in Lake Fukami-ike.” Water Research, 30 (8), pp. 1823-1832.
Zaw, Myint and Chiswell, Barry (1999). “Iron and Manganese Dynamics in Lake Water.” Water
Research, 33 (8), pp. 1900-1910.
20
Barberton Reservoir Oxygen Deficit Evaluation - Hypolimnetic Oxygenation Assessment
Appendix A - Barberton Reservoir Profiling Layout
Site 1
Depth: 3.0m
Site 3
Depth: 4.6m
Site 2
Depth: 3.4m
Site 4
Depth: 5.6m
Site 5
Depth: 6.0m
-SolarBee
Barberton Reservoir Site Coordinates (GPS)
Site 1: N 41o04.2601’_W 81o38.1805’
Site 2: N 41o04.1430’_W 81o37.8753’
Site 3: N 41o03.9610’_W 81o37.5781’
Site 4: N 41o03.6967’_W 81o37.3345’
Site 5: N 41o03.5161’_W 81o37.1084’
All coordinates were collected using Garmin eTrex Legend. The elevation at Barberton
Reservoir is 998 feet (spillway elevation).
21
Barberton Reservoir Oxygen Deficit Evaluation - Hypolimnetic Oxygenation Assessment
SBE 19 Plus V2
The Seabird SBE 19 Plus V2 has a 4Hz sample rate with a dissolved oxygen response time of 1.4
seconds, which is the slowest responding sensor. Profiles were collected to measure at a
resolution of about 5 cm and included the following constituents: Depth (m), Temperature (Co),
Specific Conductivity (uS/cm), Chlorophyll (ug/l), Turbidity (NTU), Density (kg/m3), Dissolved
Oxygen (mg/l) and Dissolved Oxygen saturation (%).
22
Barberton Reservoir Oxygen Deficit Evaluation - Hypolimnetic Oxygenation Assessment
Appendix B – Water column profiles collected with the CTD
304.0
11.
303.5
10.
9.0
303.0
8.0
Elevation (m msl)
302.5
7.0
302.0
6.0
301.5
5.0
4.5
301.0
4.0
3.5
300.5
3.0
2.5
300.0
2.0
1.5
299.5
1.0
0.0
299.0
0
500
1000
1500
2000
2500
3000
3500
4000
Distance (feet)
April 27, 2010
23
4500
5000
5500
6000
6500
7000
7500
Barberton Reservoir Oxygen Deficit Evaluation - Hypolimnetic Oxygenation Assessment
304.0
11.
303.5
10.
9.0
303.0
8.0
Elevation (m msl)
302.5
7.0
302.0
6.0
301.5
5.0
4.5
301.0
4.0
3.5
300.5
3.0
2.5
300.0
2.0
1.5
299.5
1.0
0.0
299.0
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
5500
6000
6500
7000
7500
Distance (feet)
April 30, 2010
304.0
11.
303.5
10.
9.0
303.0
8.0
Elevation (m msl)
302.5
7.0
302.0
6.0
301.5
5.0
4.5
301.0
4.0
3.5
300.5
3.0
2.5
300.0
2.0
1.5
299.5
1.0
0.0
299.0
0
500
1000
1500
2000
2500
3000
3500
4000
Distance (feet)
May 21, 2010
24
4500
5000
5500
6000
6500
7000
7500
Barberton Reservoir Oxygen Deficit Evaluation - Hypolimnetic Oxygenation Assessment
304.0
11.
303.5
10.
9.0
303.0
8.0
Elevation (m msl)
302.5
7.0
302.0
6.0
301.5
5.0
4.5
301.0
4.0
3.5
300.5
3.0
2.5
300.0
2.0
1.5
299.5
1.0
0.0
299.0
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
5500
6000
6500
7000
7500
Distance (feet)
June 4, 2010
304.0
11.
303.5
10.
9.0
303.0
8.0
Elevation (m msl)
302.5
7.0
302.0
6.0
301.5
5.0
4.5
301.0
4.0
3.5
300.5
3.0
2.5
300.0
2.0
1.5
299.5
1.0
0.0
299.0
0
500
1000
1500
2000
2500
3000
3500
4000
Distance (feet)
June 8, 2010
25
4500
5000
5500
6000
6500
7000
7500
Barberton Reservoir Oxygen Deficit Evaluation - Hypolimnetic Oxygenation Assessment
304.0
11.
303.5
10.
9.0
303.0
8.0
Elevation (m msl)
302.5
7.0
302.0
6.0
301.5
5.0
4.5
301.0
4.0
3.5
300.5
3.0
2.5
300.0
2.0
1.5
299.5
1.0
0.0
299.0
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
5500
6000
6500
7000
7500
Distance (feet)
July 2, 2010
304.0
11.
303.5
10.
9.0
303.0
8.0
Elevation (m msl)
302.5
7.0
302.0
6.0
301.5
5.0
4.5
301.0
4.0
3.5
300.5
3.0
2.5
300.0
2.0
1.5
299.5
1.0
0.0
299.0
0
500
1000
1500
2000
2500
3000
3500
4000
Distance (feet)
July 6, 2010
26
4500
5000
5500
6000
6500
7000
7500
Barberton Reservoir Oxygen Deficit Evaluation - Hypolimnetic Oxygenation Assessment
304.0
11.
303.5
10.
9.0
303.0
8.0
Elevation (m msl)
302.5
7.0
302.0
6.0
301.5
5.0
4.5
301.0
4.0
3.5
300.5
3.0
2.5
300.0
2.0
1.5
299.5
1.0
0.0
299.0
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
5500
6000
6500
7000
7500
Distance (feet)
July 23, 2010
304.0
11.
303.5
10.
9.0
303.0
8.0
Elevation (m msl)
302.5
7.0
302.0
6.0
301.5
5.0
4.5
301.0
4.0
3.5
300.5
3.0
2.5
300.0
2.0
1.5
299.5
1.0
0.0
299.0
0
500
1000
1500
2000
2500
3000
3500
4000
Distance (feet)
July 27, 2010
27
4500
5000
5500
6000
6500
7000
7500
Barberton Reservoir Oxygen Deficit Evaluation - Hypolimnetic Oxygenation Assessment
304.0
11.
303.5
10.
9.0
303.0
8.0
Elevation (m msl)
302.5
7.0
302.0
6.0
301.5
5.0
4.5
301.0
4.0
3.5
300.5
3.0
2.5
300.0
2.0
1.5
299.5
1.0
0.0
299.0
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
5500
6000
6500
7000
7500
Distance (feet)
August 4, 2010
304.0
11.
303.5
10.
9.0
303.0
8.0
Elevation (m msl)
302.5
7.0
302.0
6.0
301.5
5.0
4.5
301.0
4.0
3.5
300.5
3.0
2.5
300.0
2.0
1.5
299.5
1.0
0.0
299.0
0
500
1000
1500
2000
2500
3000
3500
4000
Distance (feet)
August 10, 2010
28
4500
5000
5500
6000
6500
7000
7500
Barberton Reservoir Oxygen Deficit Evaluation - Hypolimnetic Oxygenation Assessment
304.0
11.
303.5
10.
9.0
303.0
8.0
Elevation (m msl)
302.5
7.0
302.0
6.0
301.5
5.0
4.5
301.0
4.0
3.5
300.5
3.0
2.5
300.0
2.0
1.5
299.5
1.0
0.0
299.0
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
5500
6000
6500
7000
7500
Distance (feet)
August 17, 2010
304.0
11.
303.5
10.
9.0
303.0
8.0
Elevation (m msl)
302.5
7.0
302.0
6.0
301.5
5.0
4.5
301.0
4.0
3.5
300.5
3.0
2.5
300.0
2.0
1.5
299.5
1.0
0.0
299.0
0
500
1000
1500
2000
2500
3000
3500
4000
Distance (feet)
August 24, 2010
29
4500
5000
5500
6000
6500
7000
7500
Barberton Reservoir Oxygen Deficit Evaluation - Hypolimnetic Oxygenation Assessment
304.0
11.
303.5
10.
9.0
303.0
8.0
Elevation (m msl)
302.5
7.0
302.0
6.0
301.5
5.0
4.5
301.0
4.0
3.5
300.5
3.0
2.5
300.0
2.0
1.5
299.5
1.0
0.0
299.0
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
5500
6000
6500
7000
7500
Distance (feet)
September 1, 2010
304.0
11.
303.5
10.
9.0
303.0
8.0
Elevation (m msl)
302.5
7.0
302.0
6.0
301.5
5.0
4.5
301.0
4.0
3.5
300.5
3.0
2.5
300.0
2.0
1.5
299.5
1.0
0.0
299.0
0
500
1000
1500
2000
2500
3000
3500
4000
Distance (feet)
September 21, 2010
30
4500
5000
5500
6000
6500
7000
7500
Barberton Reservoir Oxygen Deficit Evaluation - Hypolimnetic Oxygenation Assessment
304.0
11.
303.5
10.
9.0
303.0
8.0
Elevation (m msl)
302.5
7.0
302.0
6.0
301.5
5.0
4.5
301.0
4.0
3.5
300.5
3.0
2.5
300.0
2.0
1.5
299.5
1.0
0.0
299.0
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
5500
6000
6500
7000
7500
Distance (feet)
October 1, 2010
304.0
11.
303.5
10.
9.0
303.0
8.0
Elevation (m msl)
302.5
7.0
302.0
6.0
301.5
5.0
4.5
301.0
4.0
3.5
300.5
3.0
2.5
300.0
2.0
1.5
299.5
1.0
0.0
299.0
0
500
1000
1500
2000
2500
3000
3500
4000
Distance (feet)
November 10, 2010
31
4500
5000
5500
6000
6500
7000
7500