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Mendenhall Wastewater Treatment Plant Energy Audit

Final Report August 18, 2009

Mendenhall Wastewater Treatment Plant

City and Borough of Juneau

Prepared for:

City and Borough of Juneau

Contract No. RFP E09-126

Prepared by:

Alaska Energy Engineering LLC

25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 [email protected]

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City and Borough of Juneau 1 Mendenhall WWTP Energy Audit

Table of Contents

Table of Contents 1

Project Team 2

Abbreviations 2

Section 1: Executive Summary 3 Plant Description 3 Energy Use Summary 3 Energy Conservation Opportunities 3 Facility Guidelines 7 Summary 9

Section 2: Introduction 11 Plant Description 11 Energy Use Summary 11 Methodology 13

Section 3: Buildings 17 SBR Building 17 Disinfection Building 25 Belt Filter Press Building 27 ABF Plant 28 Jet Truck Garage 29 Lube Oil Building 30 Collections Building 31

Section 4: Wastewater Treatment Process 33 Influent Pump Station 33 Sequencing Batch reactors 33 UV Treatment 34 Sludge Treatment 34 Motors 35

Section 5: Energy Conservation Opportunities 37

Appendix A: Energy Use Data

Appendix B: Energy Analysis Calculations

Appendix C: Life Cycle Cost Analysis Calculations



Project Team

Energy Engineering Jim Rehfeldt, P.E., Mechanical Engineer Alaska Energy Engineering LLC 25200 Amalga Harbor Road Juneau, Alaska 99801 907.789.1226 [email protected]

Civil Engineering Jim Dorn, P.E., Civil Engineer Carson Dorn Inc. 712 West 12th Street Juneau, Alaska 99801 907.586.4447 [email protected]

Abbreviations

AEL&P Alaska Electric Light & Power Co.

ABF Aerobic Bio-Filter

AHU Air handling unit

CBJ City and Borough of Juneau

CFL Compact fluorescent lamp

CGFP Cooling glycol feed pump

CP Circulating pump

ECO Energy conservation opportunity

EF Exhaust fan

FOP Fuel oil pump

HGFP Heating glycol feed pump

HP Horsepower

HPS High pressure sodium

HWP Heating water pump

HVAC Heating, ventilating, air-conditioning

GPM Gallons per minute

HWP Heating water pump

Inc. Incandescent

JDWWTP Juneau Douglas WWTP

kW Kilowatt

kWh Kilowatt-hour

LCB Last Chance Basin

MCC Motor control center

MWWTP Mendenhall WWTP

NPW Non-potable Water

SBR Sequencing Batch Reactor

SF Supply fan

T8 or T12 Fluorescent lamps

UV Ultraviolet

VFD Variable frequency drive

WWTP Wastewater Treatment Plant



Section 1

Executive Summary

This report presents the findings of an energy audit of the City and Borough of Juneau Mendenhall Wastewater Treatment Plant (MWWTP). The purpose of the energy audit is to identify energy conservation opportunities (ECOs) and determine if investments in energy efficiency will provide a life cycle savings.

The findings were gathered through on-site observations, review of construction documents, and interviews with operations and maintenance personnel.

The energy audit was performed by Jim Rehfeldt, P.E. of Alaska Energy Engineering LLC with technical assistance by Jim Dorn, P.E. of Carson Dorn, Inc.

PLANT DESCRIPTION

The Mendenhall Wastewater Treatment Facility processed 840 million gallons of influent in 2008. Wastewater flows through the following process:

• Influent Pump Station: The influent flows into the plant, solids are ground and a sieve removes rags. The flow settles in the influent well and is lifted into tea cup strainers that remove grit. The grit falls into a grit clarifier where it is removed.

• Sequencing Batch Reactors (SBRs): From the influent pump station, the water is distributed to one of eight SBRs where it is treated using aeration blowers and jet circulation pumps.

• UV Treatment: When an SBR completes a reaction cycle, the water is decanted and disinfected by UV treatment prior to discharge to the Mendenhall River.

• Sludge Process: Sludge from the SBRs is stored in the sludge storage tank. The sludge is dewatered in a belt filter press and trucked to the JDWWTP for incineration.

ENERGY USE SUMMARY

The plant consumes 3,000,000 kWh of electricity per year at an average electric demand of 497 kW per month. Electricity costs are $240,000 per year at an effective cost (sum of energy and demand charges) of 8.0¢ per kWh.

The plant consumes 113,000 gallons of fuel oil per year at a current cost of $215,000 per year.

ENERGY CONSERVATION OPPORTUNITIES

The energy audit revealed energy conservation opportunities associated with the buildings and the wastewater process. The energy performance of each ECO is evaluated based on the operating parameters of the water system and facilities. The economics are evaluated by a life cycle cost analysis.



Behavioral or Operational Energy Conservation Opportunities

Top priority should be given to the following behavioral or operational ECOs. Many require minimal investment and/or offer immediate savings. The savings from these ECOs is variable and depends upon the level of implementation, which cannot be readily predicted. The ECOs are listed from highest to lowest priority.

• ECO-1: Reduce Blower Room Temperature

• ECO-2: Reduce Heating Setpoints

• ECO-3: Turn Off Unneeded Lighting

• ECO-4: Reduce Unoccupied Room Temperatures

• ECO-5: Review Sludge Treatment Process

• ECO-6: Optimize SBR Blower Operation

• ECO-7: Discontinue Lube Oil Building Heat

• ECO-8: Install Interlocks on Overhead Door with Heaters

• ECO-9: Install SBR Building Main Entrance Heater Thermostat

• ECO-10: Convert HVAC Systems to DDC Controls

• ECO-11: Insulate Heating Piping

• ECO-12: Replace ABF Boiler Operating Thermostat

• ECO-13: Adjust Disinfection Building Backdraft Dampers

• ECO-14: Seal ABF Plant Exhaust Louvers and Ducts

• ECO-15: Evaluate Feasibility of Eliminating the ABF Plant Boiler

• ECO-16: Turn Off SBR Building Water Cooler

• ECO-17: Reduce SBR Building Air Compressor Pressure

• ECO-18: Insulate Collections Building Hot Water Tanks

• ECO-19: Reduce SBR Building Hot Water Temperature

• ECO-20: Install Lighting Occupancy Sensor Control

• ECO-21: Adjust and Monitor Exterior Lighting Photocells

• ECO-22: Turn Off Lab Dryer and Furnace

• ECO-23: Turn Off Idle Computers

• ECO-24: Insulate SBR Building Emergency Generator Ductwork

• ECO-25: Install Water-Conserving Aerators and Shower Heads

• ECO-26: Install Automatic Controls for EF-105A/B/C

• ECO-27: Test, Adjust, and Balance HVAC Systems

• ECO-28: Retrocommission SBR Building HVAC Systems

• ECO-29: Weather-strip Exterior Doors



High and Medium Priority Energy Conservation Opportunities

Table 1-1 is a list of each recommended ECO that will require an investment of funds. The table lists the construction, maintenance, and energy costs of each ECO over a 25-year period. The ECOs are listed from highest to lowest priority.

Table 1-1: Life Cycle Cost Analysis Summary

Energy Conservation Opportunity Construction Maintenance Energy Total LCC

High Priority ECOs

ECO-30: Turn Off SBR Lag Boiler $200 $9,300 ($155,100) ($145,600)

ECO-31: Turn Off Boilers in Summer $200 $13,900 ($97,000) ($82,900)

ECO-32: Reduce UV Output to Two Banks $1,000 ($67,600) ($154,700) ($221,300)

ECO-33: Repair AHU-101/102 Heat Recovery $2,500 $2,300 ($521,600) ($516,800)

ECO-34: Repair AHU-103/104 Heat Recovery $2,500 $2,300 ($521,600) ($516,800)

ECO-35: Install ABF Boiler Rm Heat Recovery $2,500 $1,200 ($57,300) ($53,600)

ECO-36: Replace Clothes Washer $800 $0 ($6,800) ($6,000)

ECO-37: Install AHU-105 Heat Recovery $51,500 $2,300 ($309,800) ($256,000)

ECO-38: Install Auto Valves on Unit Heaters $11,100 $0 ($69,300) ($58,200)

ECO-39: Replace HVAC Motors $13,100 $0 ($39,400) ($26,300)

Medium Priority ECOs

ECO-40: Convert to VFD Hydronic Pumping $29,100 ($4,600) ($60,800) ($36,300)

ECO-41: Insulate Collections Building Walls $42,400 $0 ($84,000) ($41,600)

ECO-42: Install MCC Room Heat Recovery $26,000 $2,300 ($49,700) ($21,400)

ECO-43: Replace Collections Bldg Windows $7,000 $0 ($11,700) ($4,700)

ECO-44: Replace Process Motors $10,000 $0 ($15,800) ($5,800)

ECO-45: Insulate Collections Bldg Roof $23,800 $0 ($34,700) ($10,900)

ECO-46: Upgrade SBR Building Lighting $1,100 $0 ($1,600) ($500)

ECO-47: Replace Older Transformers $48,300 $0 ($59,800) ($11,500)

Totals $273,100 ($38,600) ($2,250,700) ($2,016,200)

Note: Negative numbers, in parenthesis, represent savings.



Energy Savings

The following table shows the current energy costs and projected ECO energy savings.

Table 1-2: ECO Annual Energy Cost Savings

Fuel Oil Electricity Total

Existing Energy Costs $215,000 $240,000 $455,000

High Priority ECOs

ECO-30: Turn Off SBR Lag Boiler ($5,000) ($0) ($5,000)

ECO-31: Turn Off Boilers in Summer ($3,000) ($0) (3,000)

ECO-32: Reduce UV Output to Two Banks ($0) ($8,000) ($8,000)

ECO-33: Repair AHU-101/102 Heat Recovery ($19,000) $600 ($18,000)

ECO-34: Repair AHU-103/104 Heat Recovery ($19,000) $600 ($18,000)

ECO-35: Install ABF Boiler Room Heat Recovery ($2,000) ($0) ($2,000)

ECO-36: Replace Clothes Washer ($0) ($400) ($400)

ECO-37: Install AHU-105 Heat Recovery ($13,000) $3,000 ($10,000)

ECO-38: Install Automatic Valves on Unit Heaters ($2,000) ($0) ($2,000)

ECO-39: Replace HVAC Motors ($0) ($2,000) ($2,000)

Medium Priority ECOs

ECO-40: Convert to Variable Speed Hydronic Pumping ($0) ($3,000) ($3,000)

ECO-41: Insulate Collections Building Walls ($3,000) ($0) ($3,000)

ECO-42: Install MCC Room Heat Recovery ($2,000) ($0) ($2,000)

ECO-43: Replace Collections Building Windows ($400) ($0) ($400)

ECO-44: Replace Process Motors ($0) ($1,000) ($1,000)

ECO-45: Insulate Collections Building Roof ($1,000) ($0) ($1,000)

ECO-46: Upgrade SBR Building Lighting ($0) ($100) ($100)

ECO-47: Replace Older Transformers ($0) ($3,000) ($3,000)

ECO Totals ($69,000) ($13,000) ($82,000) (32%) (13%) (18%)

Note: Negative numbers, in parenthesis, represent savings.

The above table shows that the high and medium priority ECOs will provide an annual energy cost savings of 18%. Additionally, the behavioral and operational ECOs will also provide energy savings. These savings are not included in the predictions because their level of implementation cannot be accurately estimated. One ECO of note is ECO-6 (Optimize SBR Blower Operation) predicts $2,000 to $5,000 in annual electric savings if blower operation is reduced 10% or 20%, respectively.



FACILITY GUIDELINES

The following guidelines are based on the findings of the energy audit. Given the long service life of the plants, they should also be applied when possible as part of ongoing facility maintenance or renovation.

Building Envelope

None of the existing buildings are optimally insulated for the current cost of heat. The optimal insulation level depends upon the type of construction and the cost of heat, which varies with each building. An envelope optimization analysis should be performed when determining insulation levels for buildings.

Lighting

Most of the spaces are occupied a minimal number of hours each year. Turning off the lighting in these spaces will produce immediate energy cost savings.

Inexpensive fluorescent T-8 lighting is optimal for most spaces. High bay fluorescent lighting is more efficient and has a quicker startup than metal halide lighting.

Exterior lighting operates about 50% of the year. Energy efficient metal halide lighting is recommended with integral photocells. Photocell control should be fine tuned so the lighting is off during daylight hours.

Transformers

The buildings are supplied with 480V power. The benefit of a 480V service, when compared to 208V/120V service, is that smaller conductors are required and motors are slightly more efficient at higher voltages. The downside is the investment in a step-down transformer that is downstream of the utility meter. The losses of the step-down transformer are paid by the owner.

Most transformer losses are converted to heat. The heat gain to the building can be beneficial during the heating season, but is inefficient when it is not needed. There are two methods for reducing the transformer losses. First, the transformer should be right-sized. Losses are typically a percentage of the transformer capacity, so a smaller transformer costs less and has smaller losses. Second, highly energy efficient transformers should be used.

Recommendations for transformers are:

• Right-size the transformer by establishing reasonable estimates of loads. • Use energy efficient transformers. Transformers that are 15 kVA and larger should meet the

energy efficiency requirements of NEMA Standard TP 1-2001. • Locate the transformer near the floor where the heat output will create useful convective

currents, spreading the heat though the facility.



Operational Guidelines

The following guidelines were developed based on energy conservation opportunities in the existing facilities and operations. The guidelines are recommended to improve the energy performance of the water system.

Pumps

The pumps should be right-sized and selected for optimal efficiency. Variable speed pumping allows pumps to operate for longer periods at lower flow rates, which reduces energy consumption and demand charges. The many energy and operational benefits of variable speed pumping should be implemented where appropriate.

Motors

Many of the motors are less efficient than modern motors. Replacing the motors with NEMA Premium® efficient motors will reduce energy consumption and demand charges.

The energy cost of operating a motor usually exceeds the purchase price. Whether an investment in an energy efficient motor should be made depends upon the cost of the motor, cost of electricity, and the number of operating hours each year. There is no one guideline that can cover all of these variables. NEMA Premium® motors may not be available for the required frames.

The following table provides the full load efficiencies of “standard” and NEMA Premium® motors.

Table 1-3: Motor Full Load Efficiency

Horsepower “Standard” NEMA Premium®

1 76.7 to 82.5 85.5 1.5 79.1 to 84.0 86.5 2 80.8 to 84.0 86.5 3 81.4 to 87.5 89.5 5 83.3 to 87.5 89.5 7.5 85.5 to 89.5 91.7 10 85.7 to 89.5 91.7 15 86.6 to 91.0 92.4 20 88.5 to 91.0 93.0 25 89.3 to 92.4 93.6 30 89.6 to 92.4 93.6 40 90.2 to 93.0 94.1 50 91.3 to 93.0 94.5 60 91.8 to 93.6 95.0 75 91.7 to 94.1 95.4 100 92.3 to 94.5 95.4



Demand Control

AEL&P determines the electric demand by averaging demand over a continuously sliding fifteen-minute window. The highest fifteen-minute average during the billing period determines the peak demand. As a rule of thumb, each kW of peak load adds $10 in demand charges to the monthly electric bill.

The following strategies are recommended to minimize demand:

• Implement the above facility and operational guidelines at each facility. • Use variable speed pumping and equipment and establish control sequences that operate them

for longer periods at lower output. • For systems with redundant pumps and equipment, limit simultaneous operation of pumps to

emergencies and testing. Perform back-to-back tests within one billing cycle so the added demand charges are applied to a single month’s bill.

• Use NEMA Premium® energy efficient motors when operating hours warrant the investment. • Right-size the equipment such as pumps, transformers, and electric heaters.

SUMMARY

The MWWTP energy systems are in good condition and appear to be well maintained. The exception is the HVAC control system in the SBR building, which has failed. The age of the plant played a factor into the number of ECOs. There is financial incentive to invest in energy efficiency and obtain an 18% reduction in energy costs.

The energy auditor would like to express appreciation to the MWWTP operation and maintenance personnel who provided assistance during this project. Their knowledge of the plant energy systems and interest in energy efficiency was invaluable.



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Section 2

Introduction

This report presents the findings of an energy audit of the City and Borough of Juneau Mendenhall Wastewater Treatment Plant (MWWTP). The purpose of the energy audit is to identify energy conservation opportunities (ECOs) and determine if investments in energy efficiency will provide a life cycle savings.

The findings were gathered through on-site observations, review of construction documents, and interviews with operations and maintenance personnel.

The energy audit was performed by Jim Rehfeldt, P.E. of Alaska Energy Engineering LLC with technical assistance by Jim Dorn, P.E. of Carson Dorn, Inc.

PLANT DESCRIPTION


• Influent Pump Station: The influent flows into the plant, solids are ground and a sieve removes rags. The flow settles in the influent well and is lifted into tea cup strainers that remove grit. The grit falls into a grit clarifier where it is removed.

• Sequencing Batch Reactors (SBRs): From the influent pump station, the water is distributed to one of eight SBRs where it is treated using aeration blowers and jet circulation pumps.

• UV Treatment: When an SBR completes a reaction cycle, the water is decanted and disinfected by UV treatment prior to discharge to the Mendenhall River.


ENERGY USE SUMMARY

Electricity

Electricity is billed under AEL&P’s Rate 34, Large Government that charges for both electrical consumption (kWh) and peak electric demand (kW). Electrical consumption is the amount of energy consumed and electric demand is the rate of consumption. AEL&P determines the electric demand by averaging demand over a continuously sliding fifteen-minute window. The highest fifteen-minute average during the billing period determines the peak demand.

AEL&P also charges for power factor. If the power factor falls below 95% lagging, the customer must take corrective steps to return the power factor to 95% or higher. If the average power factor is less than 95% lagging, the billing demand charge will be increased by one percent (1%) for each percent or fraction thereof that the average power factor is less than ninety-five percent (95%) lagging. Power factor correction is installed at the plant, and there are no power factor charges being assessed.



Table 2-1 lists the current electric charges:

Table 2-1: AEL&P Large Government Rate

Charge 1 On-peak (Nov-May) Off-peak (June-Oct)

Energy Charge per kWh 4.93¢ 4.62¢

Demand Charge per kW $11.53 $7.35

Service Charge per month $99.24 $99.24

Four years of electrical energy usage data from AEL&P is included in Appendix A.

Energy consumption

• From 2006 to 2008, consumption averaged 3,000,000 kWh per year.

• The use dropped considerably between 2005 and 2006 after the thickened sludge tank and centrifuge was removed from service.

• Plant flows are highest in summer, yet energy use if highest during colder months. This is because cooler influent requires a longer treatment process that is more energy intensive.

Electrical Demand

• From 2006 to 2008, demand averaged 497 kW per month and has been consistent.

• The demand was 75 kW higher in 2005 due to the centrifuge that was removed from service at the end of 2005.

Costs

• During 2007-2008, annual energy costs averaged $240,000 per year.

• The monthly electric bill has the following breakdown.

1. Energy consumption (kWh) = 75%

2. Electrical demand (kW) = 24%

3. Customer charges = 1%

• Electricity has an effective cost (sum of energy and demand charges) of 8.0¢ per kWh.

• The plant has an annual load factor of 70%. This is the ratio of the average load (kW) to the peak load (kW). The plant operates at a high load factor, which indicates efficient operation, because loads are on for long periods and are not cycled for short durations. The primary benefit of a high load factor is lower demand charges, which result in a low effective cost per kWh.

Fuel Oil

Two fuel oil tanks supply the SBR Building boilers and hot water heater, the ABF Plant boiler, and the emergency generator. CBJ records show a consumption of 113,000 gallons of fuel oil in 2008.



METHODOLOGY

Energy Conservation Opportunities (ECOs)

Energy conservation opportunities were identified by evaluating the energy systems and the operating parameters of the water system. The process for identifying the ECOs acknowledges the limitations of modifying existing buildings and systems, most of which were constructed when energy costs were much lower. The ECOs represent practical measures to improve the energy efficiency of the system.

Life Cycle Cost Analysis

The ECOs are evaluated using life cycle cost analysis to determine if an energy efficiency investment will provide a savings over a 25-year life. The analysis incorporates construction, replacement, maintenance and repair, and energy costs to determine the total cost over the life of the ECO. Future maintenance and energy cash flows are discounted to present worth using escalation factors for general inflation, energy inflation, and the value of money. The methodology is based on the National Institute of Standards and Technology (NIST) Handbook 135 – Life Cycle Cost Analysis.

Life cycle cost analysis is preferred to simple payback for facilities that have long—often perpetual—service lives. Simple payback, which compares construction cost and present energy cost, is reasonable for short time periods of 2-4 years, but yields below optimal results over longer periods because it does not properly account for the time value of money or the effect inflation has on operating budgets. Accounting for energy inflation and the cost of money properly values the true cost of facility ownership and seeks to minimize the total cost over its life.

Appendix C contains the life cycle cost calculations of each ECO.

Construction Costs

The cost estimates are derived based on a preliminary understanding of the scope of each ECO as gathered during the walk-through audit. The construction costs assume in-house labor at $60 for work typically performed by maintenance staff and contract labor for larger projects and electrical work. The estimates assume some efficiency gain by being incorporated into larger, energy efficiency or other construction projects. This will spread mobilization costs over a number of ECOs and minimize costs.

When ECOs are taken for implementation, the cost estimate should be revisited once the scope and preferred method of performing the work has been determined. It is possible some ECOs will not provide a life cycle savings once the scope is finalized.

Maintenance Costs

Maintenance costs are based on in-house labor using historical maintenance efforts and industry standards. Maintenance costs are determined for the 25-year life of each ECO and represent realistic levels of effort to maintain the relative systems.

Energy Analysis

The energy performance of each ECO is evaluated using operating parameters of the water system and facilities. Appendix B contains the energy analysis calculations.



Prioritization

A prioritized ranking of the ECOs was calculated for each building using the following formula:

Prioritization Factor = Life Cycle Savings / Capital Costs

This factor puts weight on the capital cost of an ECO, which is aligned with budgeting realities that allow early implementation of low cost improvements while higher cost ECOs must wait for funding and implementation.

The ECOs are grouped into the following prioritized categories:

• Behavioral or Operational: ECOs that need minimal capital investment but require operational or behavioral changes. A life cycle cost analysis is not performed of these ECOs because the energy savings is difficult to quantify and a life cycle savings is certain.

• High Priority: ECOs that provide a life cycle savings over 200% of the capital cost. • Medium Priority: ECOs that provide a life cycle savings up to 200% of the capital cost. • Low Priority: ECOs that will save energy but do not provide a life cycle savings.

Economic Factors

Economic factors are significant to the findings and should undergo careful scrutiny.

• Nominal Interest Rate: This is the nominal rate of return on an investment without regard to inflation. The analysis uses a rate of 5.0% which is the current cost of bonds for CBJ capital improvement projects.

• Inflation Rate: This is the average inflationary change in prices over time. The analysis uses an inflation rate of 3.0% which is the consumer price index average of the past 25-years.

• Real Discount Rate: This is the actual rate of return when the inflation rate is considered. The analysis uses a real discount rate of 1.9% which is a calculated value derived from the nominal interest rate and the inflation rate.

• Economic Period: This is the period of time in which costs are considered. The analysis is based on a 25-year economic period with construction beginning in 2009.

Electricity

The electric rates are determined by Alaska Electric Light & Power Company (AEL&P) based on the provisions of their tariff. AEL&P is a privately owned utility regulated by the Regulatory Commission of Alaska. Power generation facilities utilized by AEL&P include both hydroelectric and diesel plants. Currently, the hydroelectric plants generate most of the electricity and the diesel plants provide backup.

Over recent history, electricity inflation has been less than 1% per year, which has lagged general inflation. This trend has been discontinued in recent years as fuel oil price increases led to more electric heating loads. The winter of 2007/2008 is the first extended period where AEL&P had to supplement with diesel generation. This caused a temporary Power Cost Adjustment of 1.2¢ per kWh.

In the fall of 2009, the new Lake Dorothy Hydroelectric Facility will begin producing power. The power from Lake Dorothy will be more expensive than power from the existing hydroelectric facilities. It is assumed that the community will consume most of the Lake Dorothy Phase 1 power in the near future and that the blended generation cost will raise electric rates 1.5¢ per kWh. The life cycle cost analysis includes a 1.5¢/kWh increase in electric costs.



Even with Lake Dorothy, electric heating loads are likely to continue to place demands on the hydroelectric generation facilities. A recent CBJ energy balance report indicates that Juneau’s heating loads—which are currently met with fuel oil—are 175% greater than non-heating electrical loads. Thus, there is a large potential heating load that may see some conversion to electricity if fuel oil heating prices rise above electric heating prices. In essence, electricity inflation is effected by fuel oil inflation. The life cycle cost analysis uses an electric inflation of 2.5%, which is higher than the historic average to account for future electric heating price pressures.

Fuel Oil

The CBJ is currently paying $1.90 of a gallon of heating fuel. Prices have stabilized after dropping dramatically over the past year.

Fuel oil inflation has historically averaged 6% per prior to the rapid escalation and de-escalation of prices over the past five years. The analysis assumes the fuel oil inflation will once again continue to inflate at 6%

Table 2-2: Summary of Economic and Energy Factors

Factor Rate or Cost Factor Rate or Cost

Nominal Discount Rate 5.0% Electricity Current rates + 1.5¢/kWh

General Inflation Rate 3.0% Electricity Inflation 2.5%

Real Discount Rate 1.9% Fuel Oil Cost $1.90/gal

Fuel Oil Inflation 6%






Section 3

Buildings

This section describes energy conservation opportunities associated with the buildings. The individual buildings are:

• SBR Building

• UV Disinfection Building

• Belt Filter Press Building

• Collections Office

• ABF Plant Building

• Jet Truck Building

• Lube Oil Storage Building

SBR BUILDING

Building Envelope

Description

Table 3-1: Building Envelope

Component Description (inside to outside) R-value Remarks

Walls Gyp. Bd.; metal studs; ½” sheathing; 2” ins. panel R-11 Low R-value Roof Structure; ¾” plywood; 3” rigid; metal roof R-17 Low R-value Floor slab Concrete slab-on-grade R-2 No insulation Perimeter Concrete footing; 2” rigid, inside face R-10 Windows Insulated metal frame; dbl. pane R-2.3 Low R-value Doors Main Entrance Insulated metal frame and door; dbl. pane window R-3 Grit Clarifier Insulated metal frame and door R-4 Grit Clarifier OH insulated metal door R-1 Low R-value; No bottom

weather-stripping Electrical Insulated metal frame and dbl door R-4 No center weather-

stripping Boiler Room Insulated metal frame and dbl door R-4 No center weather-

stripping Shop Insulated metal frame and door; dbl. pane window R-3 No weather-stripping Shop OH insulated metal door R-1 Low R-value; No weather-

stripping Stairs Insulated metal frame and door R-4 No weather-stripping Generator Insulated metal frame and door R-4 No weather-stripping Generator Insulated metal frame and dbl door R-4 No weather-stripping



Analysis

The walls and roofs are under insulated. Insulation can be added but the cost of removing items from the surfaces, adding insulation, and installing wallboard typically exceeds the life cycle energy savings.

The floor slabs are under insulated. However, there is no economical way to add insulation to the floor slabs.

There is no economic incentive to replace doors and frames with thermally broken units. Door weather-stripping can be installed or upgraded to seal the opening, minimizing infiltration.

Heating System

Description

The heating plant consists of two oil-fired, low-pressure steam boilers. The steam is converted to hydronic heating water in two shell and tube steam/hot water heat exchangers.

The hydronic heating system has a primary/secondary configuration and circulates a glycol antifreeze solution. Glycol pump HGFP-1 maintains system pressure by feeding glycol into the system.

• Primary pumps HWP-101/102 operate in a lead/standby configuration and circulate heating water through the heat exchangers.

• Secondary pump HWP-103 supplies the AHU-101 and 102 heating coils.

• Secondary pumps HWP-111A/B operate in a lead/standby configuration and supply the Jet Truck Garage unit heater.

• Secondary pumps HWP-112A/B operate in a lead/standby configuration and supply the SBR hydronic heating units.

• Secondary pumps HWP-114A/B operate in a lead/standby configuration and supply the Disinfection Building hydronic heating units.

Analysis

Both boilers are hot year-round. For most of the year, one boiler is capable of meeting the heating load. Keeping the unneeded second boiler on-line increases standby and cycling losses.

Secondary pumps HWP-111A/B are very oversized for the heating loads of the Tanker Garage.

Converting the secondary system to a single set of variable speed pumps will decrease pumping costs.

None of the unit heaters has an automatic valve to shut off the heating water flow when heat is not required.

The cabinet unit heater in the main entrance vestibule does not have a thermostat control. The vestibule was 75°F on a 35°F day, which is higher than needed.

The Blower Room temperature is so warm that the cooling fans in the blower enclosures are operating even when the blower is not.



Ventilation Systems

Description

West SBR:

• AHU-101 is a constant airflow cabinet fan that supplies full outside air.

• AHU-102 is a constant flow cabinet fan that exhausts air from the room.

• AHU-101 and AHU-102 have a recovery system that extracts heat from the AHU-102 exhaust air and preheats the AHU-101 supply air. Pump HWP-103 circulates water between the two heat recovery coils.

• Exhaust fan EF-112 is a constant airflow fan that provides additional exhaust.

East SBR:

• AHU-103 is a constant airflow cabinet fan that supplies full outside air.

• AHU-104 is a constant flow cabinet fan exhausting air from the room.

• AHU-103 and AHU-104 have a heat recovery system that extracts heat from the AHU-104 exhaust air and preheats the AHU-102 supply air. Pump HWP-104 circulates water between the two heat recovery coils.

• Exhaust fan EF-111 is a constant airflow fan that provides additional exhaust.

Blower Room:

• AHU-105 is a constant volume cabinet fan that supplies full outside air to the room.

• EF-101 is a constant flow system exhausting air from the room.

Influent Pump Station:

• AHU-107 is a constant flow cabinet fan that supplies full outside air to the room.

• EF-113 is a constant flow in-line fan exhausting air from the room.

Laboratory:

• AHU-109 is a constant flow cabinet fan supplying mixed air to the room. The unit has a mixing box, filter section, face and bypass dampers, heating coil, cooling coil, and supply fan.

• EF-108 is a constant flow in-line exhaust fan serving the lab canopy hoods.

Offices:

• AHU-110 is a constant flow system supplying mixed air to the rooms. The unit has a mixing box, filter section, face and bypass dampers, heating coil, cooling coil, and supply fan. Four reheat coils provide zone temperature control.

• EF-105A is a ceiling exhaust fan serving the 2nd Floor Men’s Toilet.

• EF-105B is a ceiling exhaust fan serving the 2nd Floor Women’s Toilet.

• EF-105C is a ceiling exhaust fan serving the 1st Floor Toilet.



Pipe Gallery:

• AHU-112 is a constant airflow cabinet fan that supplies full outside air. AHU-112 has a heat recovery coil.

• AHU-114 is a constant flow cabinet fan exhausting air from the room. AHU-114 has a heat recovery coil.

• Pump HWP-105 circulates water in a heat recovery loop between the two heat recovery coils.

Boiler Room:

• SF-116 is a constant flow cabinet fan that supplies full outside air to the room.

• EF-114 is a constant flow fan that transfers boiler room heat to the adjacent shop.

MCC Room: EF-104 is a wall propeller fan that exhausts air from the room. A makeup air louver with automatic damper provides makeup air when the fan operates.

Shop: EF-106 is a wall propeller fan exhausting air from the room.

Electric Room: EF-107 is a wall propeller fan that exhausts air from the room. A makeup air louver with automatic damper provides makeup air when the fan operates.

Pipe Gallery #2: EF-109 is an in-line fan that exhausts air from the room. A makeup air louver with heating coil provides tempered makeup air when the fan operates.

Pipe Gallery #3: EF-110 is an in-line fan that exhausts air from the room. A makeup air louver with heating coil provides tempered makeup air when the fan operates.

Analysis

The airflow rates in the SBR Rooms and Blower Rooms are less than the 12 ACH that is required by current codes. As such, there is no opportunity to reduce airflow and save energy.

The heat recovery loop between AHU-101 and AHU-102 is not in use. Restoring HWP-103 to operation and making the loops operational will reduce heating loads.

The heat recovery loop between AHU-103 and AHU-104 is not in use. Restoring HWP-104 to operation and making the loops operational will reduce heating loads.

There is no heat recovery loop installed for AHU-105 and EF-101. Adding heat recovery will save energy.

Exhaust fans EF-105A/B/C are controlled from wall switches. Automatic control will ensure they are off when not needed.

Exhaust Fans EF-111 and EF-112 were added in 1990 because the systems did not operate properly. The systems should be retrocommissioned and the EFs removed.

Cooling System

Description

An air-cooled chiller supplies chilled water to the cooling coils in AHU-109 and AHU-110. Cooling pump HWP-108 circulates glycol chilled water to the coils. Cooling glycol feed pump CGFP-1 maintains system pressure by feeding glycol into the system.

Analysis

The chiller did not operate in 2008. It is reported to be in poor condition due to Freon leaks.



Domestic Hot Water Heating

Description

An oil-fired, 86-gallon hot water heater supplies domestic hot water.

Analysis

The setpoint is set at 130°F. Turning it down to 120°F will reduce heat loss and protect from scalding.

Fuel Oil System

Description

Two buried fuel oil tanks, located remotely from the building, supply fuel oil for the SBR boilers and the ABF boiler. Each tank has a submersible fuel oil pump, FOP-109 and FOP-110, which operates in a lead/standby configuration. The pumps circulate fuel between the boiler burners and the tanks.

Analysis

A fuel oil pump operates continuously. Installing a day tank in each boiler room will significantly reduce pump operation.

HVAC Automatic Controls

Description

The HVAC system controls consist of an electric control system.

Analysis

The entire control system is out of calibration. Many thermostats setpoints are fully up or down and automatic valves and dampers are not controlled. The result is the building space temperatures are much higher than necessary, resulting in a considerable energy penalty due to the large outside airflow rates in the building.

The lack of a central control and monitoring station makes it difficult to verify that the systems are operating properly.



Lighting

Description

Table 3-2: Lighting Fixtures and Lamps

Room Fixture No. / Type Lamp No. / Type Control Remarks

Office Area 106 / Recessed 4 / T8 Switch

West SBR 14 / Pendant 1 /100w HPS Switch 50% delamped

6 / Pendent 1 / 250 HPS Switch

4 / Suspended 1 / 250w HPS Switch

East SBR 14 / Pendant 1 /100w HPS Switch 50% delamped

6 / Pendent 1 / 250 HPS Switch

4 / Suspended 1 / 250w HPS Switch

Blower Room 18 / Pendant 1 / 250w HPS Switch 50% delamped

MCC Room 12 / Suspended 2 / T8 Switch

Stairway 3 / surface 2 / T12 Always on Inefficient

Grit Clarifier 6 / Pendant 1 /100w HPS Switch

Influent Pump Station 6 / Pendant 1 /100w HPS Switch

Pipe Gallery 12 / suspended 2 / T12 Switch Inefficient

Tool Room 2 / Surface 2 / T8 Switch

Electrical Room 5 / Suspended 2 / T8 Switch

1st Floor Toilet 1 / Recessed 2 / T8 Switch

Boiler Room 16 / Suspended 2 / T8 Switch

Shop 47 / Suspended 2 / T8 Switch

Generator 15 / Suspended 2 / T8 Switch

Exterior 10 / Wall 1 / 70w HPS Photocell

Analysis

The remaining interior T12 and incandescent lighting has a much lower efficacy than T8 or CFL lighting.

Much of the lighting is on continuously, even in seldom-occupied areas like the Boiler Room and Pipe Gallery. Turning off lighting will reduce energy.



Electrical Equipment

Description

There is a refrigerated water cooler in the 2nf floor hallway.

The lab has a dryer and a furnace for testing samples.

There is a top loading washing machine in the Laundry Room.

Analysis

The water supply in Juneau is sufficiently cool enough that a refrigerated cooler is not necessary.

The lab fryer and furnace is continually hot at 105°C and 530°C, respectively, even though the equipment is only in use during the normal workweek. Turning it off at night and on weekends will save energy.

The top-loading washing machine is less efficient and uses more water than a front-loading washing machine.

Backup Generator

Description

The backup generator discharges cooling air through an exhaust duct and louver.

Analysis

The uninsulated exhaust duct and louver losses heat to outside. Insulating the duct will reduce the heat loss.

Transformers

The building electric supply is 480V. The following transformers step down the 480V building power to obtain 208V/120V power.

Table 3-3: Transformers

Transformer Size Remarks

Loadcenter LC1 30 kVA Less efficient

Loadcenter LC2 10 kVA No replacement




Centrifuge 20 kVA Not in service

Shop 45 kVA Less efficient

Fuel Oil Pump FOP-109 10 kVA No replacement

Fuel Oil Pump FOP-110 10 kVA No replacement

Analysis

The larger transformers are less efficient than current equipment.



Motors

Description

Table 3-4: Motors

Service Horsepower Efficiency NEMA Premium® Remarks

HWP-101 5 86.5 89.5 Less efficient





HWP-112A 5 86.5 89.5 Less efficient

HWP-112B 5 86.5 89.5 Less efficient

HWP-111A 1.5 80.0 86.5 Less efficient

HWP-111B 1.5 80.0 86.5 Less efficient

HWP-114A 1.5 80.0 86.5 Less efficient

HWP-114B 1.5 80.0 86.5 Less efficient

AHU-101 15 90.0 92.4 Less efficient





AHU-107 7.5 85.5 91.7 Less efficient





EF-101 7.5 85.5 91.7 Less efficient

EF-104 2.0 84.0 86.5 Less efficient

1. New motor efficiency is based on NEMA Premium® MG-1 efficiency motors.

Analysis

Replacing the less efficient motors with NEMA Premium® efficient motors will reduce energy consumption. Some specialized service motors may not be available as NEMA Premium®.



DISINFECTION BUILDING

Building Envelope

Description



Walls FRP Panel; 2x6 wood studs with batt; metal siding R-19 Windows Mtl frame; double pane R-1.5 Low R-value; no thermal

break Roof Attic with batt insulation R-30 Low R-value Floor slab concrete slab on grade R-2 No insulation Perimeter concrete footing, 2” rigid R-10 Low R-value Doors Entrance Insulated metal door and frame R-5 Poor weather-stripping Overhead Insulated metal door R-4

Analysis

The walls and roofs are under insulated. Insulation can be added but the cost of removing items from the surfaces, adding insulation, and installing wallboard is prohibitive to obtaining a life cycle savings.



Heating System

Description

The building is heated by the SBR Building boilers. Hydronic heating water circulates through unit heaters located in each building.

Wall thermostats control all of the unit heaters. The thermostat setpoints vary from 52°F to 70°F.

Analysis

The unit heaters do not have an automatic valve to turn off the hydronic flow when heating is not required.

Reducing the heating setpoint to 55°F will save energy while maintaining sufficient warmth to prevent freezing and control humidity.

The Jet Truck Garage overhead door and unit heater are not interlocked to turn off the heat when the door is open.



Cooling System

Description

Several of the rooms have a wall mounted exhaust fan with a backdraft damper and louver and a makeup air louver with backdraft damper. The fan operates when the room temperature exceeds the setpoint.

Analysis

Several of the backdraft dampers do not seal tightly.

Lighting

Description



Interior Rooms 23 / Suspended 2 / T8 Switch

UV Room 3 / Suspended 1 / 150w HPS Switch

1 / Suspended 2 / T8 - Always on

Tanker Garage 3 / Suspended 1 / 150w HPS Switch

Exterior 8 / Surface 1 / 50w HPS Photocell

Transformers

Description

The building electric supply is 480V power. A 75 kVA transformer steps down the 480V building power to obtain 208V/120V power.

Analysis

The transformer is less efficient than current equipment.



BELT FILTER PRESS BUILDING

Building Envelope

Description



1st Fl. Wall Gyp. bd.; 2” rigid; CMU block; metal siding R-12 Low R-value 2nd Fl. Wall 6” metal studs, insulated wall panel R-8 Low R-value Roof Metal frame, insulated roof panel R-14 Low R-value Floor slab concrete slab on grade R-2 No insulation Perimeter concrete footing, 2” rigid R-10 Low R-value

Analysis



Heating System

Description

Heat is supplied by the ABF Building boiler. Hydronic heating water circulates through unit heaters. Wall thermostats control all of the unit heaters.

Analysis

The unit heaters do not have automatic valves to turn off the hydronic flow when heat is not needed.

Lighting

Description



Interior Rooms 23 / Suspended 2 / T8 Switch

UV Room 3 / Suspended 1 / 150w HPS Switch

1 / Suspended 2 / T8 - Always on

Tanker Garage 3 / Suspended 1 / 150w HPS Switch

Exterior 8 / Surface 1 / 50w HPS Photocell



Transformers

Description

The building is supplied with 480V power for the UV equipment. A 75 kVA transformer is installed to step down the 480V building power to obtain 208V/120V power.

Analysis

The transformer is less efficient than current equipment.

ABF PLANT

Building Envelope

Description



Walls Metal frame; 2” fiberglass insulation; metal siding R-8 Low R-value Roof Metal frame; 2” fiberglass insulation; metal roof R-8 Low R-value Floor slab Concrete slab-on-grade R-2 No insulation Perimeter Concrete footing; 2” rigid, inside face R-10 Doors Uninsulated metal door and frame R-1 Low R-value; no thermal

break; no weather-stripping

OH Door Uninsulated metal door and frame R-1 Low R-value; no thermal break; no weather-stripping

Analysis




Heating System

Description

An oil-fired boiler supplies hydronic heating water to the ABF Building and the Belt Filter Press Building. Pumps CP-1 and CP-2 circulate hydronic heating water to unit heaters located in the building. Wall thermostats, set at 65°F, control all of the unit heaters.



Analysis

There is uninsulated hydronic heating piping in the boiler room.

Given the poor thermal envelope of the building, reducing the indoor temperature to 55°F will save significant amount of energy.

Ventilation Systems

Description

There are several cooling exhaust systems with louvers. These systems are no longer operational.

Analysis

The exhaust ducts, fans, and louvers are not sealed and there are noticeable leaks to the outside. Remove the units and seal the openings to minimize heat loss.

Lighting

Description



Plant 21 / Pendent 1 / 250w HPS Switch -

Work bench 5 / Suspended 2 / T8 Switch -

JET TRUCK GARAGE

Building Envelope

Description



Walls Gyp. bd.; 2x6 with batt; metal siding R-19 Roof Attic with batt insulation R-30 Low R-value Floor slab concrete slab on grade R-2 No insulation Perimeter concrete footing, 2” rigid R-10 Low R-value Doors OH Door Insulated metal door R-2 Low R-value; No thermal

break; No weather-stripping

Door Insulated metal frame and door R-3 Low R-value; No thermal break; No bottom weather-stripping



Analysis




Heating System

Description

The SBR Building boiler heats the building. Hydronic heating water circulates through a unit heater controlled by a wall thermostat. The setpoint is 60°F.

Analysis

The unit heater does not have an automatic valve to turn off the hydronic flow when heat is not needed.

The thermostat is inaccurate; the room was 71°F.

Lighting

Description



Garage 8 / Surface 2 / T12 Switch 8’ lamps

LUBE OIL BUILDING

Building Envelope

Description

There is no data on the building envelope.

Heating System

Description

Two electric unit heaters keep the building warm. The building temperature is 57°F.



Lighting

Description



Garage 4 / Surface 1 / 75w HPS Switch

COLLECTIONS BUILDING

Building Envelope

Description



Walls 8” concrete block R-2 Low R-value Windows Wood casement; single pane R-1.0 Low R-value; poor

weather-stripping Roof Wood roof deck, 1” rigid, built-up roof R-7 Low R-value Floor slab concrete slab on grade R-2 No insulation Perimeter concrete footing, 1” rigid R-5 Low R-value Doors Main Entrance Insulated metal door and frame; single pane window R-1.5 Low R-value; no thermal


Break Room Insulated metal door and frame; single pane window R-1.5 Low R-value; no thermal break; no weather-stripping

Back Office Insulated metal door and frame R-5 No weather-stripping Back Door Insulated metal door and frame; single pane window R-1.5 Low R-value; no thermal


Analysis

The walls and roofs are under-insulated. Adding insulation to the exterior is the best option for improving the walls.





Heating System

Description

The ABF Plant boiler heats the building. Hydronic heating water circulates through baseboard and unit heaters. Electric heaters also supply supplemental heating on cold days.

Wall thermostats control the hydronic heaters. Integral thermostats control the electric heaters. The thermostat setpoints varied from 70°F to 75°F.

Analysis

The hydronic and electric heaters have separate thermostats set at different temperatures. Larger hydronic heaters controlled by a single thermostat will improve thermal comfort and temperature control.

The unit heaters do not have automatic valves to turn off the hydronic flow when heat is not needed.

Domestic Hot Water System

Description

An electric hot water heater supplies the building.

Analysis

The heater is located in a cold room. Adding an insulating blanket will reduce heat loss.

The unit heaters do not have an automatic valve to turn off the hydronic flow when heat is not needed.

Lighting

Description


Room Fixture No. / Type Lamp No. / Type Control

Interior Rooms 33 / Surface 2 / T12 Switch



Section 4

Wastewater Treatment Process


• Influent Pump Station: The influent flows into the plant, solids are ground and a sieve removes rags. The flow settles in the influent well and the influent pumps lift it to tea cup strainers that remove the grit. The grit falls into a grit clarifier that removes it for disposal.

• Sequencing Batch Reactors (SBRs): From the influent pump station, the water distributes to one of eight SBRs where it is treated using aeration blowers and jet circulation pumps.

• UV Treatment: When an SBR completes a reaction cycle, the water decants to the UV treatment channel prior to discharge to the Mendenhall River.


INFLUENT PUMP STATION

Description

The wastewater flows into the influent pump station and passes through a grinder that breaks up solids and a sieve that catches rags. A rag screw removes the rags from the flow upstream of the wet well. Influent pumps lift the flow into centrifugal tea cups, which separates grit from the flow; the grit drops into a grit snail clarifier where it is dewatered. The wastewater flows to a distribution box that distributes it the SBRs.

Analysis

There are five influent pumps of equal capacity. They operate in sequence, typically with one pump capable of handling the flow, except for an average of one hour per day when two pumps operate. During periods of low flow, the lead pump cycles on and off with influent well water elevation. Variable speed pumps would be able to operate based on actual flow, saving energy and demand charges.

SEQUENCING BATCH REACTORS

Description

There are eight SBR tanks where treatment occurs. The reaction process consists of aeration by air blowers and jet pumps and settling periods. Upon completion of the react cycle, the water decants to the UV treatment.

Analysis

A consultant is working with plant operators to optimize the treatment process.



UV TREATMENT

Description

The treated water flows through a channel where it is treated with UV radiation.

Analysis

The UV system consists of three banks of UV lights. The system is sized so that two banks are able to treat the water with the third as backup. Turning off one bank will reduce energy consumption.

If the decant flow was lowered so decanting occurs nearly continuously and lower flow rates, one bank may be sufficient to disinfect the effluent.

A recirculating pump maintains the water level over the lamps when there is no flow. This pump operates because the weir gate that maintains the water elevation is leaking. Repairing the gate would reduce pump operation.

SLUDGE TREATMENT

Description

A sludge tank aerates the sludge with an air blower and jet pump. The sludge transfers via a sludge grinder to the belt filter press for dewatering into a dry cake. The cake is trucked to the JDWWTP for incineration.

Analysis

The amount of sludge has increased in recent years from 500 to 800 dry metric tons per year. The increase is due to operational changes in 2005 that included taking the centrifuge and thickened sludge tank out of service. A review of the changes is warranted in consideration of the increased sludge production.



MOTORS

Description

Table 4-1: Motors

Service Horsepower Efficiency NEMA Premium® Remarks

Influent Pump Station Influent Pumps P1I-P5I 50 n/a 94.1 Integral with pump Auger Monster 5 87.5 89.5 Less efficient Rag Screw 2 82.0 86.5 Less efficient SBR Basins Blowers 1-8 60 95.4 95.0 Jet Pumps P1J-P8J 36 n/a 94.1 Integral with pump Sludge Pumps P1S-P8J 16 n/a 92.4 Integral with pump Sludge Tank Blower 10 25 91.7 93.6 Less efficient Secondary Grinder 3 84.0 89.5 Less efficient Decant Pumps P1WS-P2WS 5 n/a 89.5 Integral with pump Transfer Pumps P3WS-P4WS 10 88.5 91.7 Less efficient Transfer Pump P5WS 15 88.0 2 92.4 Less efficient UV Treatment Recirculation Pumps Other Control Air Compressor 15 88.0 2 92.4 Less efficient NPW Pump North 20 89.5 93.0 Less efficient NPW Pump South 20 89.5 93.0 Less efficient NPW Booster Pump 10 87.0 2 91.7 Less efficient NPW Air Compressor 5 84.0 2 89.5 Less efficient NPW Chlorinator 5 84.0 2 89.5 Less efficient

1. New motor efficiency is based on NEMA Premium® MG-1 efficiency motors. 2. No motor data available; motor efficiency assumed.

Analysis

Many of the motors are operated a significant number of hours each year to warrant replacement with a NEMA Premium® motor. Some specialized service motors may not be available as NEMA Premium®.






Section 5

Energy Conservation Opportunities

Behavioral or Operational Energy Conservation Opportunities

Top priority should be given to the following behavioral or operational ECOs that require minimal investment and offer immediate savings. The ECOs are listed from highest to lowest priority.

ECO-1: Reduce Blower Room Temperature

Purpose: The temperature in the blower room was 68°F on the day of the energy audit. Each blower enclosure has a cooling fan that circulates cooling air when the enclosure temperature exceeds 65°F. The temperature in the blower room causes the cooling fans to operate, even when the blower is off. Reducing the blower room temperature will minimize blower cooling fan energy and save heating energy.

Scope: Turn down the setpoint in the SBR Building blower room.

Recommendation: This ECO is recommended without additional analysis.

ECO-2: Reduce Heating Setpoints

Purpose: The temperature in many of the intermittently occupied rooms was 70-75°F, which is much higher than needed to control humidity and provide thermal comfort. Reducing the temperature will save heating energy.

Scope: Reduce the temperature of all intermittently occupied rooms.


ECO-3: Turn Off Unneeded Lighting

Purpose: Throughout the plant, the lighting in some rooms is left on when rooms are not occupied. Turning off lighting will reduce energy use.

Scope: Turn off lighting in unoccupied rooms.


ECO-4: Reduce Unoccupied Room Temperatures

Purpose: The building temperature is constant even though the building is unoccupied during nights and weekends. Setting back the temperature during this time will reduce heating energy by 10-15%.

Scope: Use a night setback control to turn down the temperature at night and restore the occupied temperature prior to building occupancy each day. This ECO is applicable to all buildings.




ECO-5: Review Sludge Treatment Process

Purpose: The sludge treatment process changed in 2005, resulting in a 60% increase in the number of dry tons incinerated at the JDWWTP. A review of incinerator fuel oil records for the incinerator show that fuel oil consumption increased by 7,000 gallons, or 8%.

Scope: Review the change in sludge treatment process and determine if the increase in fuel oil consumption is reasonable.


ECO-6: Optimize SBR Blower Operation

Purpose: The SBR blowers are currently being modulated on a times sequence. Optimizing blower operation with dissolve oxygen control is likely to reduce blower airflow and save energy.

Scope: Optimize blower operations by using DO control to vary the blower airflow rate.

Analysis: It is not possible to estimate the extent that DO control will reduce blower airflow.

If DO control reduces blower airflow by 10%, this ECO will annually reduce electric use by 24,000 kWh, and energy costs by $1,500.

If DO control reduces blower airflow by 20%, this ECO will annually reduce electric use by 72,000 kWh, and energy costs by $4,600.

Blower Output Construction Maintenance Energy Total Life Cycle Cost

10% Reduction $1,000 $0 ($28,600) ($27,700) 20% Reduction $1,000 $0 ($84,600) ($83,700) Note: Negative numbers, in parenthesis, represent savings.

Recommendation: This ECO is recommended.

ECO-7: Discontinue Lube Oil Building Heat

Purpose: The Lube Oil Building is a thermally inefficient structure that is heated to store lubricants. If the lubricants were stored in another heated building, the Lube Oil Building could be unheated.

Scope: Move the materials that require heat to another building and turn off the heat in the Lube Oil Building.


ECO-8: Install Interlocks on Overhead Door with Heaters

Purpose: A considerable amount of heat escapes when overhead doors are open. Interlocking the heaters so they turn off while the doors are open will reduce the heat loss, especially on occasions where the doors are left open for long periods.

Scope: Interlock the heaters with overhead doors so the heaters are off when the doors are open. This ECO is applicable to the SBR Building, ABF Plant, UV Building, Tanker Truck Building, and Lube Oil Building.

Recommendation: This ECO is recommended without analysis. Interlocking overhead doors is good practice.



ECO-9: Install SBR Building Main Entrance Heater Thermostat

Purpose: The cabinet unit heater in the main entrance of the SBR Building does not have a thermostat to control the heat output. It supplies heat continuously during the heating season, but is turned off the rest of the year. Installing thermostatic control will limit the heat output.

Scope: Install a thermostat and control valve to modulate the heat output of the cabinet unit heater.

Recommendation: This ECO is recommended without additional analysis. Thermostatic control of the heater is good practice.

ECO-10: Convert HVAC Systems to DDC Controls

Purpose: The automatic control systems in the SBR Building are not providing adequate control. Many thermostats are turned fully up or down, a sign of a loss of control. The building’s fuel consumption is high due to poor control strategies and lack of good thermal control.

Consideration should also be given in a plant-wide DDC control system that will give maintenance personnel a central interface for monitoring the facilities.

Scope: Convert the facility to a central DC control system. Estimated cost for the SBR Building is $310,000 and $430,000 for the entire facility. Develop optimized control strategies that incorporate the following:

• Optimal Operating Schedules

• Reducing Outside Air Flow using Humidity Monitoring

• Scheduled Ventilation Control

• Ventilation Supply Air Reset Control

• HVAC Occupancy Sensor Control

• Temperature Setback


ECO-11: Insulate Heating Piping

Purpose: Insulating heating piping decreases heat loss and has a short payback.

Scope: Add pipe insulation to the heating piping in the ABF Plant boiler room and the Tanker Truck Garage.


ECO-12: Replace ABF Boiler Operating Thermostat

Purpose: Boilers are more efficient if they operate for long operating cycles and long off cycles. The ABF boiler efficiency can be improved by increasing the operating thermostat differential and by installing a modulating burner. The existing burner is not modulating and the control is operating the boiler on a 10°F differential. A new operating thermostat with a larger differential is needed.

Scope: Install a modulating burner and a new boiler controller and set the operating range from 160-190°F.




ECO-13: Adjust Disinfection Building Backdraft Dampers

Purpose: The Disinfection Building has backdraft dampers for the exhaust fans and makeup air louvers that do not seal tightly when the fan is off. Adjusting the dampers so they seal tightly will reduce infiltration.

Scope: Adjust the Disinfection Building backdraft dampers for the exhaust fans and makeup air louvers so they seal tightly when the fan is off.


ECO-14: Seal ABF Plant Exhaust Louvers and Ducts

Purpose: The ABF Plant has numerous wall and roof penetrations for exhaust fans that are no longer in use. The unsealed penetrations allow heated air to escape to outdoors.

Scope: Seal the wall and roof duct penetrations in the ABF Plant.


ECO-15: Evaluate Feasibility of Eliminating the ABF Plant Boiler

Purpose: The SBR Boilers supply the SBR Building, Tanker Truck Building, and Lube Oil Building. The ABF Plant Boiler supplies the ABF Plant and Collections Building. By implementing many of the ECOs that reduce heating loads, the SBR boilers should have sufficient capacity to supply the entire facility.

Scope: Connect the ABF Plant and Collections Building heating loads to the SBR Building boilers.

Analysis: This ECO is only feasible if ECOs once ECOs that reduce heating loads are implemented. An analysis of the feasibility of supplying all loads by the SBR boilers is beyond the scope of this energy audit.

Recommendation: Aggressive implementation of heating ECOs is recommended to improve the feasibility of this ECO.

ECO-16: Turn Off SBR Building Water Cooler

Purpose: The SBR Building has a drinking fountain with a cooling unit. Juneau’s water supply is sufficiently cold enough that mechanical chilling is not needed. Turning off the cooler will reduce energy use.

Scope: Turn off the water cooler.


ECO-17: Reduce SBR Building Air Compressor Pressure

Purpose: The air compressor maintains the storage tank at sufficient pressure for the influent control valves. The valves will soon be replaced with lower pressure actuators. The air compressor pressure should be turned down once the actuators are replaced to save energy.

Scope: Reduce the operating pressure of the air compressor when the influent valves are replaced.




ECO-18: Insulate Collections Building Hot Water Tanks

Purpose: The hot water tank in the Collections Building is located in a cold room that increases tank heat loss. Wrapping the tank in an insulating blanket will decrease heat loss.

Scope: Wrap the hot water heater in an insulating blanket.


ECO-19: Reduce SBR Building HW Temperature

Purpose: The hot water tank supplies 130°F hot water to the fixtures. Reducing the setpoint to 120°F will reduce tank heat loss and piping heat loss and minimize scalding potential.

Scope: Reduce the hot water heater setpoint to 120°F.


ECO-20: Install Lighting Occupancy Sensor Control

Purpose: Occupancy sensors automatically turn off lighting in unoccupied rooms, saving energy. They are proven energy saving devices.

Scope: Install occupancy sensors to control lighting in offices, toilet rooms, laboratory, etc.


ECO-21: Adjust and Monitor Exterior Lighting Photocells

Purpose: Several exterior light fixtures remain on during daylight hours. Adjusting or replacing the internal photocell on each fixture so it turns off during daytime will save lighting energy.

Scope: Adjust the exterior lighting photocells so the lamps are off during the day. This ECO is applicable to the UV Building.


ECO-22: Turn Off Lab Dryer and Furnace

Purpose: The lab dryer and furnace are kept continuously hot even though they are only used during normal Monday to Friday work hours. Turning them off overnight and on weekends will save energy.

Scope: Turn off the dryer and furnace overnight and on weekends.


ECO-23: Turn Off Idle Computers

Purpose: Computers and peripheral equipment is often left on continuously. Turning them off during non-working hours will save energy.

Scope: Turn off computers and peripheral equipment during non-working hours.




ECO-24: Insulate SBR Building Emergency Generator Ductwork

Purpose: The ductwork connected to the generator discharge is uninsulated, increasing heat loss through the ductwork to the outdoors. Insulating the ductwork will reduce heat loss.

Scope: Insulate the generator exhaust ductwork.


ECO-25: Install Water-Conserving Aerators and Shower Heads

Purpose: The plumbing fixtures do not have water-conserving aerators and shower heads. Installing water-conserving aerators and shower head will reduce hot water consumption.

Scope: Install water-conserving aerators and shower heads.


ECO-26: Install Automatic Controls for EF-105A/B/C

Purpose: Exhaust Fans EF-105A/B/C supply the toilet rooms and are controlled by wall switches. Automatic control of the fans will ensure they only operate during occupied periods.

Scope: Provide scheduled automatic control of Exhaust Fans EF-105A/B/C.


ECO-27: Test, Adjust, and Balance HVAC Systems

Purpose: Mechanical systems are dynamic systems where operating parameters such as air balancing, water balancing can change over time. Observations by building occupants and operators indicate that the systems are no longer balanced.

Scope: Test, adjust, and balance the mechanical systems.


ECO-28: Retrocommission SBR Building HVAC Systems

Purpose: The commissioning process provides verification that the building systems operate as intended. Reportedly, the SBR Building systems were not properly commissioned as there were problems from the beginning. Retrocommissioning the system will ensure they are operating properly and as efficiently as possible.

Scope: Retrocommission the HVAC systems.


ECO-29: Weather-strip Exterior Doors

Purpose: The weather-stripping on many of the doors is poor or does not exist. Adding weather-stripping will reduce heat loss and minimize infiltration of damp air into the building.

Scope: Replace or add door weather-stripping. This ECO is applicable to nearly all doors.




High Priority Energy Conservation Opportunities

High priority ECOs provide a high life cycle savings for the relative investment. The ECOs are listed from highest to lowest priority.

ECO-30: Turn off SBR Lag Boiler

Purpose: Hot boilers have jacket, standby, and cycling losses of 1-3% of their input rating. The losses can be 100% of the input energy if the boiler is not supplying heat to the building. Turning off unneeded boilers will improve the seasonal efficiency of the heating pant.

Scope: Turn off the SBR lag boiler from March to November when there is no risk of freezing the building if the lead boiler fails.

Analysis: This ECO will annually reduce fuel oil use by 2,880 gallons, and energy costs by $5,500.

Construction Maintenance Energy Total Life Cycle Cost

$200 $9,300 ($155,100) ($145,600) Note: Negative numbers, in parenthesis, represent savings.


ECO-31: Turn off Boilers During Summer

Purpose: Boilers of the size in the SBR and ABF Buildings have jacket, standby, and cycling losses of 1% of their input rating. The losses can be 100% of the input energy if the boiler is not supplying heat to the building. Turning off boilers will improve the seasonal efficiency of the heating plant.

Scope: Turn off the SBR and ABF boilers when heat is not needed from June 1 to September 1.


Construction Maintenance Energy Total Life Cycle Cost $200 $13,900 ($97,000) ($82,900) Note: Negative numbers, in parenthesis, represent savings.




ECO-32: Reduce UV Output to Two Banks

Purpose: The UV system has three banks of lamps that operate continuously. The system is sized so two banks are capable of providing sufficient disinfection at current decanting flow rates. If the decanting flow rate is reduced, resulting in a more continuous effluent flow rate, one bank may be sufficient. Either operation will result in energy savings.

Scope: Reduce UV system output to two banks or reduce the decant flow and reduce to one bank.

Analysis: Trojan UV states that no depreciation in lamp life will occur as long as the lamp cycles are limited to three per day. The proposed strategy is daily operation of each lamp to limit the accumulation of growth. For one bank operation, each bank would operate steady for 8 hours per day. For two-bank operation, each bank would operate steady for 16 hours per day. Reducing UV output will also increase the service life of each lamp.

If two banks are operated, this ECO will annually reduce electric use by 109,000 kWh, electric demand by 150 kW, and energy costs by $8,300.

If decant flow rates are reduced so one bank is operated, this ECO will annually reduce electric use by 218,000 kWh, electric demand by 300 kW, and energy costs by $16,700.

UV Output Construction Maintenance Energy Total Life Cycle Cost Two Banks $1,000 ($67,600) ($154,700) ($221,300) One Bank $1,900 ($135,200) ($309,400) ($442,700) Note: Negative numbers, in parenthesis, represent savings.


ECO-33: Repair SBR Building AHU-101/AHU-102 Heat Recovery

Purpose: The heat recovery loop between AHU-101 and AHU-102 has been removed from service. Restoring the heat recovery will significantly reduce energy consumption.

Scope: Return the AHU-101/102 heat recovery loop to operation.


Construction Maintenance Energy Total Life Cycle Cost $2,500 $2,300 ($521,600) ($516,800) Note: Negative numbers, in parenthesis, represent savings.




ECO-34: Repair SBR Building AHU-103/104 Heat Recovery

Purpose: The heat recovery loop between AHU-103 and AHU-104 has been removed from service. Restoring the heat recovery will significantly reduce energy consumption.

Scope: Return the AHU-103/104 heat recovery loop to operation.




ECO-35: Install ABF Plant Boiler Room Heat Recovery

Purpose: The ABF Plant boiler room is hot due to heat gain from the boiler. Install a fan to distribute the heat to adjacent spaces.

Scope: Install a wall and fan to transfer the boiler heat to the ABF Plant.




ECO-36: Replace Clothes Washer

Purpose: A top-loading washing machine is less-efficient and uses more water than a front-loading model. Replacing the washing machine with a front-loading model saves energy and hot water.

Scope: Replace the clothes washer with a front-loading model.

Analysis: This ECO will annually reduce electric use by 6,100 kWh and energy costs by $370.


Construction Maintenance Energy Total Life Cycle Cost $800 $0 ($6,800) ($6,000) Note: Negative numbers, in parenthesis, represent savings.



ECO-37: Install SBR Building AHU-105 Heat Recovery System

Purpose: AHU-105 supplies 12,450 cfm of ventilation air to the Blower Room. Adding a heat recovery loop that transfers heat from the exhaust air will save energy.

Scope: Install a heat recovery coil in AHU-105. Return EF-101 to service and install a heat recovery coil in the inlet duct. Install a heat recovery loop between the two coils and provide controls.




ECO-38: Install Unit Heater Automatic Valves

Purpose: The unit heater coil is kept continuously hot, even when heat is not required. Installing an automatic valve that shuts of heating supply flow when heat is not needed will reduce standby losses.

Scope: Install automatic valves in the unit heater heating supply with thermostat control. This ECO is applicable to all buildings.

Analysis: This ECO will annually reduce fuel oil use by 660 gallons, and energy costs by $1,300.

Construction Maintenance Energy Total Life Cycle Cost $11,100 $0 ($69,300) ($58,200) Note: Negative numbers, in parenthesis, represent savings.


ECO-39: Replace HVAC Motors

Purpose: Motor efficiencies have improved in recent years with the acceptance of the NEMA Premium MG-1 standard. Replacing less efficient motors with NEMA Premium® motor will reduce energy and demand costs.

Scope: Replace motors the following motors with NEMA Premium® energy efficient motors: HWP-101/102, HWP-103/104, HWP-111A/B, HWP-114A/B, AHU-101, , AHU-102, AHU-103, AHU-104, AHU-105, , AHU-107.

Analysis: This ECO will annually reduce electric use by 28,000 kWh, electric demand by 39 kW, and energy costs by $2,100.





Medium Priority Energy Conservation Opportunities

Medium priority ECOs provide life cycle energy savings that exceed the investment cost required to implement the change. These ECOs have a lower priority because the cost of implementation is high or the savings is minimal.

ECO-40: Convert to Variable Speed Hydronic Pumping

Purpose: The SBR Building hydronic heating system uses constant speed pumps to circulate heating water. These pumps consume nearly the same amount of energy year-round. Variable speed pumps allow pumping energy to decrease as heating loads decrease. The SBR Building boilers serve a large enough load that variable speed pumps can significantly reduce pumping costs.

Scope: Replace the secondary constant speed pumps with one pair of variable speed pumps.


Construction Maintenance Energy Total Life Cycle Cost $29,100 ($4,600) ($60,800) ($36,300) Note: Negative numbers, in parenthesis, represent savings.


ECO-41: Insulate Collections Building Walls

Purpose: The walls in the Collections Building are significantly under-insulated. Adding insulation to the wall exterior and residing the building will reduce energy costs.

Scope: Add insulation and metal cladding to the exterior of the Collections Building walls. Cover or provide access to some electrical conduits.

Analysis: This ECO will, on an annual basis, reduce fuel oil use by 1,600 gallons, and energy costs by $3,000.



ECO-42: Install SBR Building MCC Room Heat Recovery

Purpose: The electrical equipment in the MCC Room generates considerable amounts of heat. This heat is discharged outdoors by an exhaust fan. Modifying the system so that the warm air is supplied to adjacent rooms when they need heat or to an SBR Room will reduce energy use.

Scope: Modify the MCC Room cooling system to supply the warm air to adjacent exterior rooms.

Analysis: This ECO will annually reduce fuel oil use by 900 gallons, and energy costs by $1,800.





ECO-43: Replace Collections Building Windows

Purpose: The Collections Building has inefficient single pane windows. Replacing the windows will save energy and improve occupant comfort.

Scope: Replace the single pane windows in the collections building.

Analysis: This ECO will, on an annual basis, reduce fuel oil use by 220 gallons, and energy costs by $400.



ECO-44: Replace Process Motors

Purpose: Motor efficiencies have improved in recent years with the acceptance of the NEMA Premium MG-1 standard. Replacing less efficient motors with NEMA Premium® motor will reduce energy and demand costs.

Scope: Replace the following motors with NEMA Premium® energy efficient motors: Auger Monster; Rag Screw; Secondary Grinder; Sludge Pump P5WS; NPW Pumps; NPW Booster; NPW Chlorinator.

Analysis: This ECO will annually reduce electric use by 9,278 kWh, electric demand by 28 kW, and energy costs by $860.



ECO-45: Insulate Collections Building Roof

Purpose: The Collections Building roof is significantly under insulated. Typically, adding insulation to a roof does not provide a life cycle savings. However, the roof is so under insulated that energy savings may offset the insulation cost.

Scope: Add insulation and a new roof membrane to the Collections Building roof.

Analysis: This ECO will, on an annual basis, reduce fuel oil use by 640 gallons, and energy costs by $1,200.





ECO-46: Upgrade SBR Building Lighting

Purpose: The SBR Building has a few T12 lighting fixtures that have lower efficacy than newer technologies such as T8 and T5 lighting. Reballasting and relamping the fixtures with T8 lamps will save energy.

Scope: Reballast and relamp existing fixtures with T8 lamps.

Analysis: This ECO will annually reduce electric use by 980 kWh and energy costs by $60.

Construction Maintenance Energy Total Life Cycle Cost $1,100 $0 ($1,600) ($500) Note: Negative numbers, in parenthesis, represent savings.


ECO-47: Replace Older Transformers

Purpose: The step down transformers in the buildings have lower efficiencies than modern, energy efficient transformers. Replacing the transformers will save electricity.

Scope: Replace older dry-type transformers with newer energy efficient models. This ECO is applicable to the SBR Building and UV Building.




Low Priority Energy Conservation Opportunities

Low priority ECOs do not offer a life cycle energy savings and are not recommended.

ECO-48: Replace Influent Pumps, Install VFDs

Purpose: The influent pumps are the original pumps. Replacing the pumps with more efficient modern pumps will reduce energy costs.

The influent pumps cycle on and off to maintain wet well levels. Variable speed operation would minimize energy and demand changes by matching the pump output to the influent flow rate.

Scope: Replace the three influent pumps and install VFDs.

Analysis: This ECO will annually reduce electric use by 28,000 kWh, electric demand by 378 kW, and energy costs by $48,000. Unfortunately, an investment in new pumps and VFDs does not provide a life cycle savings.

Construction Maintenance Energy Total Life Cycle Cost $150,000 $0 ($101,700) $48,300 Note: Negative numbers, in parenthesis, represent savings.

Recommendation: This ECO is not recommended.



ECO-49: Install Boiler Daytanks

Purpose: The fuel oil system that supplies the boilers consists of two buried fuel tanks with submersible fuel oil pumps. One pump operates continuously to supply fuel to the boilers. Installing boiler daytanks will allow the pumps to operate only a fraction of each day to refill the daytanks.

Scope: Install a daytank and controls in the SBR Building and ABF Plant Boiler Room. Tie the daytank controls into the fuel pump starters to operate the lead fuel pump to fill a daytank.

Analysis: This ECO will annually reduce electric use by 9,800 kWh, electric demand by 12 kW, and energy costs by $740. However, it does not provide a life cycle savings due to the cost of control wiring and interface with the fuel pump starters.

Construction Maintenance Energy Total Life Cycle Cost $16,500 $4,600 ($13,600) $7,500 Note: Negative numbers, in parenthesis, represent savings.


ECO-50: Replace Influent Pumps

Purpose: The influent pumps are the original pumps. Replacing the pumps with more efficient modern pumps will reduce energy costs.

Scope: Replace three influent pumps with more efficient pumps.

Analysis: The water-to-wire efficiency of the existing and proposed pumps is 63% and 69%, respectively. This ECO will annually reduce electric use by 25,000 kWh, electric demand by 41 kW, and energy costs by $2,000. Unfortunately, an investment in new pumps does not provide a life cycle savings.

Construction Maintenance Energy Total Life Cycle Cost $112,500 $0 ($37,200) $75,300 Note: Negative numbers, in parenthesis, represent savings.


ECO-51: SBR Building – AHU-112/114 Heat Recovery

Purpose: The heat recovery loop between AHU-112 and AHU-114 has been removed from service. The fans are currently used sparingly. If fan use increases in the future, restoring the heat recovery will reduce energy consumption.

Scope: If the operating hours of AHU-112/114 increase significantly in the future, return the heat recovery loop to operation.

Recommendation: This ECO is not recommended unless the number of AHU-112/114 operating hours is increased.



ECO-52: Replace Exterior Doors

Purpose: Many of the metal doors and frames are not thermally broken. This allows a direct conducive path of heat to the outside, significantly reducing the door R-value. Replacing the doors and frames with thermally broken units will reduce heat loss.

Scope: Replace non-thermally broken doors and frames. This ECO is applicable to nearly all doors.

Recommendation: This ECO is not recommended. Past analysis has shown that energy savings will not offset the costs of replacing the doors and frames.

ECO-53: Install Collections Building Arctic Entrance

Purpose: Arctic entrances save energy by reducing infiltration when exterior doors are opened. They offer the greatest savings on heavily used doors. The main entrance and side entrance at the Collections Buildings is heavily used and worthy of having an arctic entrance.

Scope: Install an arctic entrance at the main entrance of the Collection’s Building

Analysis: An arctic entrance requires sufficient length between the inner and outer doors so one shuts before the other opens. The building is space constrained indoors and on the site so that this distance is not readily available.






City and Borough of Juneau Mendenhall WWTP Energy Audit

Appendix A

Energy Use Data




Alaska Energy Engineering LLC Electric Use Data 25200 Amalga Harbor Road Tel/Fax: 907-789-1226 Juneau, Alaska 99801 [email protected]

Mendenhall Wastewater Treatment PlantELECTRIC RATE

Electricity ($ / kWh ) 0.0493 0.0462Demand ( $ / kW ) 11.53 7.35Customer Charge ( $ / mo ) 99.24 99.24Power Cost Adjustment ( $ / kWh ) 0.012037 0.012037Regulatory Cost Charge ( $ / kWh ) 0.000362 0.000362Sales Tax ( % ) 0.0% 0.0%

ELECTRICAL CONSUMPTION AND DEMAND

kWh kW kWh kW kWh kW kWh kWJan 319,600 590 266,300 537 264,400 541 231,360 491 1,081,660Feb 300,800 597 243,100 503 257,760 459 283,360 536 1,085,020Mar 305,900 591 234,800 487 255,360 421 237,440 491 1,033,500Apr 325,200 586 250,700 476 228,000 472 242,240 504 1,046,140May 280 300 578 231 400 486 268 640 480 199 520 443 979 860

March 27, 2009

2008

AEL&P Electric Rate 34On-PeakNov-May

Off-peakJun-Oct

Month2005 2006 2007

Average

May 280,300 578 231,400 486 268,640 480 199,520 443 979,860Jun 293,300 566 234,900 495 255,360 467 222,880 416 1,006,440Jul 328,400 569 262,000 505 218,720 456 219,680 435 1,028,800Aug 303,500 591 256,600 502 278,560 472 245,600 491 1,084,260Sep 308,900 603 288,700 562 234,400 480 236,160 475 1,068,160Oct 339,600 624 272,600 612 255,680 544 228,480 488 1,096,360Nov 270,000 617 272,400 552 295,520 547 264,160 475 1,102,080Dec 263,100 534 279,600 545 263,520 520 265,280 533 1,071,500Total 3,638,600 3,093,100 3,075,920 2,876,160 3,170,945

Average 303,217 587 257,758 522 256,327 488 239,680 482 264,245

Load Factor 70.7% 67.7% 71.9% 68.2% 520

ELECTRIC BILLING DETAILS

Month Energy Demand Cust & Tax Total Energy Demand Cust & Tax Total % ChangeJan 16,313 6,238 99 22,650 14,275 5,661 99 20,035 -11.5%Feb 15,904 5,292 99 21,295 17,483 6,180 99 23,762 11.6%Mar 15,755 4,854 99 20,709 14,650 5,661 99 20,410 -1.4%Apr 14,067 5,442 99 19,609 14,946 5,811 99 20,856 6.4%May 16,575 5,534 99 22,208 12,310 5,108 99 17,517 -21.1%Jun 14,964 3,432 99 18,496 13,061 3,058 99 16,217 -12.3%Jul 12,817 3,352 99 16,268 12,873 3,197 99 16,170 -0.6%Aug 16,323 3,469 99 19,892 14,392 3,609 99 18,100 -9.0%Sep 13,736 3,528 99 17,363 13,839 3,491 99 17,429 0.4%Oct 14,983 3,998 99 19,080 13,389 3,587 99 17,075 -10.5%

Nov 18,233 6,307 99 24,639 16,298 5,477 99 21,874 -11.2%Dec 16,259 5,996 99 22,354 16,368 6,145 99 22,612 1.2%

Total $ 185,929 $ 57,443 $ 1,191 $ 244,562 $ 173,883 $ 56,985 $ 1,191 $ 232,059 -5.1%

Average $ 15,494 $ 4,787 $ 99 $ 20,380 $ 14,490 $ 4,749 $ 99 $ 19,338 -5.1%

Cost ($/kWh) 0.0795 75% 25% 1% 0.0807 1.5%

Electrical costs are based on the current electric rates.

2007 2008

Page 1

Alaska Energy Engineering LLC Yearly Comparison 25200 Amalga Harbor Road Tel/Fax: 907-789-1226 Juneau, Alaska 99801 [email protected]


March 27, 2009

100,000

150,000

200,000

250,000

300,000

350,000

400,000

kWh

Energy Use Comparison

0

50,000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

2005 2006 2007 2008

0

100

200

300

400

500

600

700


kW

Energy Demand Comparison

2005 2006 2007 2008

Page 2

Alaska Energy Engineering LLC Annual Comparison 25200 Amalga Harbor Road Tel/Fax: 907-789-1226 Juneau, Alaska 99801 [email protected]


March 27, 2009

$ 5,000

$ 10,000

$ 15,000

$ 20,000

$ 25,000

Energy Cost Breakdown

$ 0Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Energy (kWh) Costs Demand (kW) Costs Customer Charge and Taxes

0

100

200

300

400

500

600

0

50,000

100,000

150,000

200,000

250,000

300,000


Dem

and (kW)

Ener

gy U

se (k

Wh)

Energy and Demand Comparison

Energy Demand

Page 3




Appendix B

Energy Analysis Calculations




Alaska Energy Engineering LLC CALCULATIONS 25200 Amalga Harbor Road Tel/Fax: 907.789.1226 Juneau, Alaska 99801 [email protected]

CBJ Public Works Energy Audits

Mendenhall Wastewater Treatment PlantAnnual Flows

Gal/Mo Months MGal/yr MGPD70 12 840 2.3

Replace Collections Building WindowsArea Rold Rnew Tin Tout kBTU Boiler Effic Fuel, gals100 1.0 4.7 70 41 19,999 68% 218

Insulate Collections Building WallsArea Rold Rnew Tin Tout kBTU Boiler Effic Fuel, gals

1,240 2.0 22.0 70 41 143,186 68% 1,560

Insulate Collections Building RoofArea Rold Rnew Tin Tout kBTU Boiler Effic Fuel, gals

1,914 7.0 47.0 70 41 59,116 68% 644

ABF Boiler Room Heat RecoveryInput MBH Losses Loss, MBH % recov Gain MBH Boiler Effic Fuel, gals

2,240 1.0% 22.4 50% 11 68% 1,069

Turn off SBR Lag BoilerInput MBH Losses Loss, MBH % Gain MBH Months Boiler Effic Fuel, gals

7,870 0.75% 59.0 75% 44 9 75% 2,880

August 18, 2009

Turn off Boilers During SummerBoiler Input MBH Losses Loss, MBH % Gain MBH Months Boiler Effic Fuel, galsSBR 7,870 0.75% 59.0 100% 59 3 75% 1,280ABF 2,240 1.0% 22.4 100% 22 3 70% 521

1,801

Fuel Oil DaytanksPump HP kWH

1.5 9,802

SBR Building Variable Speed Hydronic PumpingExist Pumps Service GPM Head.fixed Head, var ηp ηm HP kW KWHHWP-112 SBR Hydronic 380 12 28 65% 86.5% 6.8 5.10 44,658HWP-114 UV Bldg 80 12 20 60% 80.0% 1.3 1.01 8,810HWP-111 Jet Truck 80 12 20 60% 80.0% 1.3 1.01 8,810

540 9.5 7.1 62,279

New Pump Service GPM Head.fixed Head, var ηp ηm HP kW KWHFull Load SBR Hydronic 540 12 28 68% 91.7% 8.8 6.53 57,222Ave Load SBR Hydronic 250 12 14 68% 91.7% 2.6 1.97 17,220

Savings 5.1 45,0599-months

Page 1




August 18, 2009

Install AV on Unit HeatersLoss, BTUH Number Factor Loss, kBTU Boiler Effic Fuel, gals

1,500 37 25% 121,545 70% 1,286

AHU-101/102 Heat RecoveryUnit CFM Troom Tosa kBTU η, hr kBTU saved Boiler Effic Fuel, gals

AHU-101/102 17,650 55 41 2,337,764 40% 935,105 70% 9,895

Unit GPM Head ηp ηm HP kW KWHHWP-103 123 20 60% 84.0% 1.2 0.92 8,063

AHU-103/104 Heat RecoveryUnit CFM Troom Tosa kBTU η, hr kBTU saved Boiler Effic Fuel, gals

AHU-103/104 17,650 55 41 2,337,764 40% 935,105 70% 9,895

Unit GPM Head ηp ηm HP kW KWHHWP-104 123 20 60% 84.0% 1.2 0.92 8,063

AHU-105 Heat RecoveryUnit CFM Troom Tosa kBTU η, hr kBTU saved Boiler Effic Fuel, gals

AHU-105 12,450 55 41 1,649,017 40% 659,607 70% 6,980

Unit GPM Head ηp ηm HP kW KWHHWP XXX 100 20 60% 84 0% 1 0 0 75 6 555HWP-XXX 100 20 60% 84.0% 1.0 0.75 6,555

Unit GPM in water ηf ηm HP kW KWHEF-101 12,000 1.3 55% 91.7% 7.8 5.83 51,095

MCC Room Heat RecoveryGain, kW Gain, MBH CFM Tsa Trm Boiler Effic Fuel, gals

3 10 3,920 75 72 72% 923

Page 2




August 18, 2009

Convert to DDC ControlsNumber Pts/ea Total

SBR BuildingBoiler Room

Boilers 2 2 4Fuel oil tanks 2 1 2Fuel oil pumps 2 2 4Pumps 11 2 22Combustion fan 1 2 2Heat recovery fan 1 2 2Heating supply temps 1 2 2

Ventilation SystemsAHU-101 1 2 2AHU-102 1 0 0AHU-103 1 14 14AHU-104 1 6 6AHU-105 1 13 13AHU-107 1 6 6AHU-109 1 8 8AHU-110 1 8 8AHU-112 1 12 12

Exhaust SystemsEF-101 1 13 13EF-104 1 0 0EF-105A/B/C 1 3 3EF-106 1 5 5EF-107 1 2 2EF-109 1 4 4EF-110 1 5 5EF-111/112 2 3 6EF-113 1 3 1EF-114 1 3 3

Heating SystemsUnit Heaters 19 4 76CUH 2 0 0

Cooling SystemsChiller 1 3 3CW Pump 1 0 0

ABF PlantBoiler Room

Boilers 1 5 5Pumps 2 2 4

Heating SystemsUnit Heaters 6 2 12

UV BuildingExhaust Systems

Exhaust fans w/ma damper 2 0 0Heating Systems

Unit Heaters 7 5 35

Page 3




August 18, 2009

Belt Filter Press BldgExhaust Systems

Exhaust fans w/ma damper 2 0 0Heating Systems

Unit Heaters 3 5 15Collections Bldg

Exhaust SystemsExhaust fan 1 0 0

Heating SystemsBaseboard heater 3 5 15Unit Heaters 2 0 0

Jet Truck BuildingHeating Systems

Unit Heaters 1 0 0

Totals SBR TotalNumber of Points 228 314Cost per Point $1,250 $1,250

$285,000 $392,500

SBR Building Lighting UpgradesRoom Fixtures Lamps old watts new watts kW savings hours/day kWhStairs 3 2/T12 72 58 0.0 24 368

Pipe Gallery 12 2/T12 72 58 0.2 10 61315 0.2 981

Replace Washing MachineWasher Gallons/cycle Loads/wk % HW HW Use, gal kWhExisting 36.9 35 100% 67,158 13,129

New 19.8 35 100% 36,036 7,04531,122 6,084

Replace Transformers

Building KW ηold ηnew KW kWhSBR Building 15 94.0% 97.0% 0.45 3,942SBR Building 15 94.0% 97.0% 0.45 3,942SBR Building 25 95.8% 97.9% 0.53 4,599SBR Building 30 94.6% 97.3% 0.81 7,096SBR Building 45 95.4% 97.7% 1.04 9,067UV Building 75 96.0% 98.0% 1.50 13,140

4.8 41,785.2

Page 4




August 18, 2009

Upgrade HVAC MotorsBuilding Service HP Hours η,exist η,new ΔKW ΔKWH

SBR HWP-101 5.0 4,380 87% 89.5% 0.14 633SBR HWP-102 5.0 4,380 87% 89.5% 0.14 633SBR HWP-103 2.0 8,760 83% 86.5% 0.08 733SBR HWP-104 2.0 8,760 83% 86.5% 0.08 733SBR HWP-112A 5.0 4,380 87% 89.5% 0.14 633SBR HWP-112B 5.0 4,380 87% 89.5% 0.14 633SBR HWP-111A 1.5 4,380 80% 86.5% 0.11 460SBR HWP-111B 1.5 4,380 80% 86.5% 0.11 460SBR HWP-114A 1.5 4,380 80% 86.5% 0.11 460SBR HWP-114B 1.5 4,380 80% 86.5% 0.11 460SBR AHU-101 15.0 8,760 90% 92.4% 0.32 2,829SBR AHU-102 10.0 8,760 86% 91.7% 0.57 4,989SBR AHU-103 15.0 8,760 90% 92.4% 0.32 2,829SBR AHU-104 10.0 8,760 86% 91.7% 0.57 4,989SBR AHU-105 10.0 8,760 89% 91.7% 0.25 2,162SBR AHU-107 7.5 8,760 86% 91.7% 0.44 3,876SBR AHU-109 2.0 8,760 84% 86.5% 0.05 450SBR AHU-110 2.0 8,760 84% 86.5% 0.05 450SBR EF-104 2.0 8,760 84% 86.5% 0.05 450

3.8 28,863

Upgrade Process MotorsUpgrade Process MotorsBuilding Service HP Hours η,exist η,new ΔKW ΔKWH

SBR Auger Monster 5.0 8,760 87.5% 89.5% 0.10 834

SBR Rag Screw 2.0 8,760 82.0% 86.5% 0.09 829

SBR Secondary Grinder 3.0 3,285 84.0% 89.5% 0.16 538

SBR Transfer Pumps P3WS-P4WS 10.0 1,825 88.5% 91.7% 0.29 537

SBR Transfer Pump P5WS 15.0 3,285 88.0% 92.4% 0.61 1,989

SBR NPW Pumps North/South 20.0 4,380 89.5% 93.0% 0.63 2,748

SBR NPW Booster Pump 10.0 3,285 87.0% 91.7% 0.44 1,444

SBR NPW Chlorinator 5.0 3,285 84.0% 89.5% 0.27 896

2.6 9,816

Upgrade Influent Pumps

Pump GPM Head ηp HP ηm kW Hours KWH

Exist 2,100 64 74% 45.9 85.0% 40.29 7,391 297,807

New 2,100 64 76% 44.7 90.5% 36.85 7,391 272,347

3.4 25,459

Page 5




August 18, 2009

Replace Influent Pumps and Install VFDs

Average Flow Rate MGPD GPM

2.300 1,597

Exist

Pump GPM Head ηp ηm HP kW Hrs/day MGPD KWH

Lead 2,100 64 74% 85.0% 54.0 40.29 20.25 2.55 297,817

Lead/Lag 4,200 64 74.0% 85.0% 108.0 80.59 1.0 0.252 29,414

2.30 327,231

New Pump w/VFD

Pump GPM Head ηp ηm HP kW Hrs/day MGPD KWH

Lead 1,770 64 76% 90.5% 41.6 31.06 24.0 2.55 272,068

Lead/Lag 2,800 64 76% 90.5% 65.9 49.13 1.5 0.252 26,899

49.1 2.30 298,968

Savings 31.5 28,263

Variable UV Bank Operation

Turn One Bank Off

Mode Lamps watts/ea Hours kW KWH

Exist 576 65 8,760 37.4 327,974

1 ff 384 65 8 760 25 0 218 6501 off 384 65 8,760 25.0 218,650

Savngs 12.5 109,325

Turn Two Banks Off

Mode Lamps watts/ea Hours kW KWH

Exist 576 65 8,760 37.4 327,974

2 off 192 65 8,760 12.5 109,325

Savngs 25.0 218,650

Annual Lamp Cost

Cost Life, hrs $/lamp yr

$25.00 12,000 $18.25

Blower Modulation

Mode Batch/day Batch/yr kW Hrs kW Hrs kW Hrs kWh

Exist 35 12,775 45 0.17 40 0.17 37 1.67 968,771

90% Flow 35 12,775 44.5 0.17 39.0 0.17 36.0 1.67 944,285

Savings 24,485

80% Flow 35 12,775 44.0 0.17 37.0 0.17 34.0 1.67 896,379

Savings 72,392

95% Speed 60% Speed 40% Speed

Page 6



Appendix C

Life Cycle Cost Analysis Calculations




Alaska Energy Engineering LLC Life Cycle Cost Analysis25200 Amalga Harbor Road Tel/Fax: 907.789.1226Juneau, Alaska 99801 [email protected]

Mendenhall Wastewater Treatment PlantBasis

25 Study Period (years) 3.0% General Inflation5.00% Nominal Discount Rate 6.0% Fuel Inflation1.94% Real Discount Rate 2.5% Electricity Inflation

ECO-6: Optimize SBR Blower DO Control - 10% Reduction Qty Unit Base Cost Year 0 Cost

Construction CostsControl implimentation and testing 16 hr $60 $960

Energy CostsElectric Energy 1 - 25 -24,485 kWh $0.063 ($28,626)

Net Present Worth ($27,666)

ECO-6: Optimize SBR Blower DO Control - 20% Reduction Qty Unit Base Cost Year 0 CostConstruction Costs

Control implimentation and testing 16 hr $60 $960Energy Costs

Electric Energy 1 - 25 -72,392 kWh $0.063 ($84,634)Net Present Worth ($83,674)

ECO-30: Turn Off SBR Lag Boiler Qty Unit Base Cost Year 0 Cost

Construction CostsTurn off lag boiler 4 hrs $50 $200

Annual CostsBoiler shutdown and startup 1 - 25 8 hrs $60.00 $9,258

Energy CostsFuel Oil 1 - 25 -2,880 gal $1.90 ($155,137)

0

0

August 18, 2009

Year

Year

0

Year

Fuel Oil 1 25 2,880 gal $1.90 ($155,137)Net Present Worth ($145,679)

ECO-31: Turn Off Boilers in Summer Qty Unit Base Cost Year 0 Cost

Construction CostsTurn off lag boiler 4 hrs $50 $200

Annual CostsBoiler shutdown and startup 1 - 25 12 hrs $60.00 $13,887



Year

0

Page 1



August 18, 2009

ECO-32: Reduce UV Output to Two Banks Qty Unit Base Cost Year 0 Cost

Construction Costs 16 hrs $60 $960Annual Costs

Lamp replacement 1 - 25 -192 lamps $18.25 ($67,583)Energy Costs

Electric Energy 1 - 25 -109,000 kWh $0.063 ($127,433)Electric Demand 1 - 25 -150 kW $9.79 ($27,251)


ECO-32: Reduce UV Output to One Bank Qty Unit Base Cost Year 0 CostConstruction Costs 32 hrs $60 $1,920Annual Costs

Lamp replacement 1 - 25 -384 lamps $18.25 ($135,167)Energy Costs

Electric Energy 1 - 25 -218,000 kWh $0.063 ($254,866)

Electric Demand 1 - 25 -300 kW $9.79 ($54,503)Net Present Worth ($442,615)

ECO-33: Repair SBR Building AHU-101/102 Heat Recovery Qty Unit Base Cost Year 0 Cost

Construction CostsReplace HWP-103 1 ea $2,000 $2,000Refill and recommission system 1 ea $500 $500

Annual CostsPump maintenance 1 - 25 2 hrs $60.00 $2,314

Energy Costs

0

0Year

Year

Year

00

Energy CostsFuel Oil 1 - 25 -9,895 gal $1.90 ($533,015)Electric Energy 1 - 25 8,060 kWh $0.063 $9,423Electric Demand 1 - 25 11 kW $9.79 $2,028


ECO-34: Repair SBR Building AHU-103/104 Heat Recovery Qty Unit Base Cost Year 0 Cost

Construction CostsReplace HWP-104 1 ea $2,000 $2,000Refill and recommission system 1 ea $500 $500

Annual CostsPump maintenance 1 - 25 2 hrs $60.00 $2,314



ECO-35: Install ABF Boiler Room Heat Recovery Qty Unit Base Cost Year 0 Cost

Construction CostsInstall wall exhaust fan and fire damper 1 ea $2,500 $2,500

Annual CostsFan maintenance 1 - 25 1 hrs $60.00 $1,157

Energy CostsFuel Oil 1 - 25 -1,070 gal $1.90 ($57,638)Electric Energy 1 - 25 263 kWh $0.063 $307


Year

0

Year

00

Page 2



August 18, 2009

ECO-36: Replace Clothes Washer Qty Unit Base Cost Year 0 Cost

Construction CostsFront-loaidng clothes washer 1 ea $750 $750

Energy CostsElectric Energy 1 - 25 -6,084 kWh $0.06 ($6,774)


ECO-37: Install AHU-105 Heat Recovery Qty Unit Base Cost Year 0 Cost

Construction CostsInstall heat recovery coils in AHU-105 and EF-101 1 ea $30,000.00 $30,000Hydronic piping and pump 1 ea $18,000.00 $18,000Controls 1 ea $3,500.00 $3,500

Annual CostsPump and coil maintenance 1 - 25 2 hrs $60.00 $2,314



ECO-38: Install Automatic Valves on Unit Heaters Qty Unit Base Cost Year 0 Cost

Construction CostsInstall automatic valve 37 ea $200.00 $7,400Controls 37 ea $100.00 $3,700

Energy CostsFuel Oil 1 25 1 286 gal $1 90 ($69 273)

Year

0

0

00

Year

Year

0

0

Fuel Oil 1 - 25 -1,286 gal $1.90 ($69,273)Net Present Worth ($58,173)

ECO-39: Replace HVAC Motors Qty Unit Base Cost Year 0 Cost

Construction CostsReplace HWP-101 Motor 1 ea $820.00 $820Replace HWP-102 Motor 1 ea $820.00 $820Replace HWP-103 Motor 1 ea $600.00 $600Replace HWP-104 Motor 1 ea $600.00 $600Replace HWP-112A/B Motor 2 ea $820.00 $1,640Replace HWP-111A/B Motor 2 ea $590.00 $1,180Replace HWP-114A/B Motor 2 ea $590.00 $1,180Replace AHU-101 Motor 1 ea $1,750.00 $1,750Replace AHU-102 Motor 1 ea $1,150.00 $1,150Replace AHU-104 Motor 1 ea $1,150.00 $1,150Replace AHU-105 Motor 1 ea $1,150.00 $1,150Replace AHU-107 motor 1 ea $1,080.00 $1,080

Energy CostsElectric Energy 1 - 25 -27,514 kWh $0.063 ($32,167)Electric Demand 1 - 25 -40 kW $9.79 ($7,267)


00

Year

0

0

0

0

0

0

0

0

0

0

Page 3



August 18, 2009

ECO-40: Convert to Variable Speed Hydronic Pumping Qty Unit Base Cost Year 0 Cost

Construction CostsRemove HWP-112A/B,111A/B, 114 A/B and piping 1 ea $3,500 $3,500Install new HWP-112A/B, 10 HP 2 ea $3,000 $6,00010 HP VFD 2 ea $6,800 $13,600Revise heating unit control valves and controls 1 ea $6,000 $6,000

Annual CostsLess pump maintenance 1 - 25 -8 hr $60.00 ($9,258)VFD maintenance 1 - 25 4 hr $60.00 $4,629



ECO-41: Insulate Collections Building Walls Qty Unit Base Cost Year 0 Cost

Construction Costs4" rigid to outside 1240 sqft $2.75 $3,410Electric details 1 job $8,000.00 $8,000New metal siding 1240 sqft $25.00 $31,000



ECO-42: Install SBR Building MCC Room Heat Recovery Qty Unit Base Cost Year 0 Cost

Construction CostsSupply duct system diffusers automatic dampers 1 ea $18 000 $18 000

0

00

Year

0

Year

0

0

Year

0

0Supply duct system, diffusers, automatic dampers 1 ea $18,000 $18,000Controls 1 ea $8,000 $8,000

Annual CostsMaintenance 1 - 25 2 ea $60.00 $2,314

Energy CostsFuel Oil 1 - 25 -923 gal $1.90 ($49,719)


ECO-43: Replace Collections Building Windows Qty Unit Base Cost Year 0 Cost

Construction CostsRepalce windows with triple pane vinyl windows 100 sqft $70 $7,000



Year

0

00

Page 4



August 18, 2009

ECO-44: Replace Process Motors Qty Unit Base Cost Year 0 Cost

Construction CostsReplace Auger Monster Motor 1 ea $820.00 $820Replace Rag Screw Motor 1 ea $600.00 $600Replace Secondary Grinder Motor 1 ea $670.00 $670Replace Transfer Pump P5WS Motor 1 ea $1,750.00 $1,750Replace Non-potable Water Pump Motors 2 ea $2,080.00 $4,160Replace Non-potable Water Booster Pump Motor 1 ea $1,150.00 $1,150Replace NPW Chlorinator motor 1 ea $820.00 $820



ECO-45: Insulate Collections Building Roof Qty Unit Base Cost Year 0 Cost

Construction Costs10" rigid insulation 1914 sqft $6.00 $11,484Builtup Roof 1914 sqft $5.00 $9,570Demo, blocking and flashing 182 lnft $15.00 $2,730



ECO-46: Upgrade SBR Building Lighting Qty Unit Base Cost Year 0 Cost

Construction CostsReballast and relamp T12 light fixtures 15 ea $75 00 $1 125

0

Year

000

0

0

Year

Year

0

0

00

0

Reballast and relamp T12 light fixtures 15 ea $75.00 $1,125Energy Costs

Electric Energy 1 - 25 -981 kWh $0.063 ($1,147)Electric Demand 1 - 25 -2 kW $9.79 ($436)

Net Present Worth ($458)

ECO-47: Replace Older Transformers Qty Unit Base Cost Year 0 Cost

Construction CostsSBR Building: Replace 15 KVA 1 ea $5,800.00 $5,800SBR Building: Replace 15 KVA 1 ea $5,800.00 $5,800SBR Building: Replace 25 KVA 1 ea $6,800.00 $6,800SBR Building: Replace 30 KVA 1 ea $7,500.00 $7,500SBR Building: Replace 45 KVA 1 ea $9,000.00 $9,000UV Building: 75 KVA 1 ea $13,400.00 $13,400



00

00

0

0

0

Year

Page 5



August 18, 2009

ECO-48: Replace Influent Pumps, Install VFDs Qty Unit Base Cost Year 0 Cost

Construction CostsReplace Influent Pumps 3 ea $37,500 $112,500Install VFD + Integration 3 ea $12,500 $37,500


Net Present Worth $48,284

ECO-49: Install Boiler Daytanks Qty Unit Base Cost Year 0 Cost

Construction CostsInstall daytank 2 ea $3,500 $7,000SBR daytank controls 1 ea $1,500 $1,500ABF daytank controls 1 ea $8,000 $8,000

Annual CostsDaytank Maintenance 1 - 25 4 hrs $60.00 $4,629



ECO-50: Replace Influent Pumps Qty Unit Base Cost Year 0 Cost

Construction CostsReplace Influent Pumps 3 ea $37,500 $112,500

Energy CostsElectric Energy 1 25 25 459 kWh $0 063 ($29 764)

Year

00

Year

0

00

0

Year

Electric Energy 1 - 25 -25,459 kWh $0.063 ($29,764)Electric Demand 1 - 25 -41 kW $9.79 ($7,412)


Page 6

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