making financial and environmental sustainability the ... · buildings and grounds 30 minor...

Making Financial and Environmental Sustainability the Focus for WWTP Improvements

Joseph R. Tucker, PECity Engineer

City of Marietta, OH

Dale E. Kocarek, PE, BCEEStantec Consulting Engineers

Columbus, OH

May 15th, 2013 ‐ Session #8260APWA Sustainability In Public Works

San Diego, CA

Learning Objective #1

APWA Sustainability In Public WorksSan Diego, CA

• Identify several ways that you can increase revenues without raising sewer rates.

• For example, the City of Marietta, OH worked collaboratively with Washington County Commissioners to create and implement an Intergovernmental Agreement which will allow the municipality to increase sewer revenues by approximately 12% by providing service outside its corporation boundaries without adding any additional staff.



• Use specific ideas, approaches and resources presented at this session to improve the financial and environmental sustainability of your wastewater treatment plant and facilities.

• These concepts can and should be investigated and applied during the planning, design, selection of equipment, and construction administration of your next project.



• Present one example of a low cost innovative approach taken by a small City to improve operations and long term sustainability at its municipal wastewater treatment plant while retaining one of the largest employers in an economically distressed region of the United States.

What would Thomas Edison have to say about the opportunities associated with Financial and Environmental Sustainability?

“Opportunity is missed by most people because it is dressed in overalls and looks a lot like work.”

Background

• Marietta Ohio is a “river” town on the Ohio River in the Appalachian Region.

• The City has been at 15,000 population since 1940.

• The Marietta WWTP was built in 1955 and upgraded in 1987.

Background

• The City of Marietta Ohio Wastewater Treatment Plant (WWTP) is an activated sludge plant with a rated capacity of 3.35 MGD.

• It has an NPDES permit that requires it to meet secondary treatment limits with a discharge into the Ohio River.

• The plant has minimal remaining capacity for new users, which include development opportunities.

• Mechanical problems are common place.

Background

• The plant was plagued by continuing acute episodes of activated sludge bulking, which resulted in effluent violations.

• In 2003, these effluent violations were so severe that the Ohio EPA had requested a plan of action.

• During May 2003, the plant incurred more than 30 day violations.

• Based on a typical penalty cost of $500/parameter/day, the possible penalty was estimated at $15,000/month.

Background‐WWTP Condition AssesmentCity of Marietta WWTP

Asset Condition Assessment

Unit Process Failure Likelihood in

%

Severity of Failure

Likely Mode of Failure Capital Project Proposed

Flow Equalization Basin 80 Minor Piping and liner deterioration NoMechanical Screen 100 Major Structural breakage YesPump House Wet Well 100 Major Structural collapse YesPump House Pumps 80 Major Mechanical NoGrit Removal 0 Minor N/A NoPre‐Aeration 10 Minor N/A NoPrimary Sedimentation 50 Moderate Mechanical components at end

of lifeNo

Aeration Tank System 20 Moderate Air delivery system inefficient YesFinal Clarifiers 100 Major Process YesUV Disinfection 100 Major Undersized and energy

inefficientYes

Plant Hydraulics 50 Major Capacity challenge for wet weather flows

Yes

Sludge Thickening 100 Moderate Solids process challenge YesSludge Digestion 100 Major Failed on January 3, 2010 YesSludge Dewatering 50 Major No redundancy YesElectrical and Instrumentation

100 Major Lack of available power Yes

Buildings and Grounds 30 Minor Repair/replacement of building systems

No

Organic Loading 100 Major Process failure and compliance problems

Yes

CMOM/Wet Weather 70 Major CMOM compliance failure Yes

Purpose of the Renovation Program

• Renovate and modernize an old facility where equipment is at or beyond its useful life (fully retired assets)

• Provide additional capacity (and a revenue source) by serving additional areas, several of which to not have sewer service

• Improves water quality for areas that will be “sewered” and endangering a unique population of fresh water mussels

• Provide operational stability and NPDES permit compliance, because without NPDES permit compliance no other goals are possible!

Financial Challenges

• Marietta is a small city, and the only significant funding source is through the SRF program

• Ohio has no significant statewide grants program for water infrastructure

• The only significant “grants” program favors roads, bridges and storm infrastructure.

Purpose of the Renovation Program

• Use the opportunity to incorporate sustainable practices and features.

• Sustainable practices and features include those that increase revenue, improve water quality, conserve energy, reduce the carbon footprint, and reduce labor and operating cost.

• Take advantage of financial incentives for energy through the AEP GridSmart program.

Putting a Plan into Action

• The City has adopted a multi‐faceted strategy to reduce both capital and long term operating costs by increase revenue.

• This will be done through the pursuit of intelligent design and other initiatives.

• The reduction in energy has the benefit of reducing the carbon footprint.

• Improve the “water environment” through the Ohio SRF Water Resources Restoration Sponsorship Program (Ohio)

Specific Examples to be Discussed1. Increase revenue through the City‐County Intergovernmental Agreement.

2. Demand Response program to increase revenue.

3. Addition of an automated state‐of‐the‐art sludge handling system to improve efficiency and reduce labor costs.

4. Recirculation of Effluent provides savings and conservation of potable water.

5. Septage Receiving can be installed to provide additional revenues.

6. Reduce O&M costs through an energy efficient UV disinfection system.

7. Participate in the Ohio SRF Water Resources Restoration Sponsorship Program (Ohio) to provide an environmental benefit.

8. Add a biological selector to improve process operations and reduce energy cost.

9. Reduce night‐time staffing and labor cost through SCADA.

How can you IncreaseRevenues with Flat Projections for Population and Business Growth?

Investigate the financial and environmental benefits of an Intergovernmental Agreement!

What is an Intergovernmental Agreement?The most common form involves a formal contract for sanitary sewer services between two jurisdictions under which one government agrees to provide sanitary sewer services to another government for an agreed upon price.

IGA Case Study – City of Marietta, OHand Washington County

What are the specific financial benefits of the Intergovernmental Agreement (IGA) for the County? The IGA provided the most cost effective solution for the

County to address existing problems for the residential areas of Devola and Oak Grove located a few miles north of the City.

The Average Estimated Total Present Worth Cost to build a new WWTP in Devola including O&M Costs = $10,716,977

The Average Estimated Total Present Worth Cost to build Lift Stations and transport sewage to City of Marietta’s Collection System including O&M Costs = $7,388,058

Washington County saves $3,328,919 with IGA!


What are the specific financial benefits of the Intergovernmental Agreement (IGA) for the City?

The IGA provides the following timeline for residential areas to tie into the City WWTP : – Existing Devola sewer customers - December, 2012 (completed)– Oak Grove – Phase One - December, 2013– Future Devola sewer customers - December, 2015– Oak Grove – Phase Two - December, 2016

Starting in 2017, the City of Marietta will increase its Average Daily Flow by 0.30 MGD and increase it’s sanitary sewer revenues by 11.7% with IGA!

Increased Revenue = $372,000/year based on 0.2 MGD Present Worth = $5,534,320 based on 3.0% APR


What are the specific environmental benefits of the Intergovernmental Agreement (IGA)?

Elimination of a point source discharge into the Muskingum River.

Improperly functioning septic systems have resulted in high nitrate levels in the area’s drinking water. The IGA will allow for expansion of sanitary sewer collection system to replace failing septic systems.

To download a copy of Marietta’s IGA:http://www.mariettaoh.net/government/wastewater/reports

Demand Response - Another example of how to increase your revenues!

What is Demand Response?• According to Federal Energy Regulatory Commission, Demand Response (DR) is

defined as: “Changes in electric usage by end‐use customers from their normal consumption patterns in response to changes in the price of electricity over time, or to incentive payments designed to induce lower electricity use at times of high wholesale market prices or when system reliability is jeopardized.”

• Source: Federal Energy Regulatory Commission 18 CFR Part 35Docket No. RM10‐17‐000; Order No. 745Demand Response Compensation in Organized Wholesale Energy Markets (Issued March 15, 2011)

• During critical times of high demand or high prices a Regional Transmission Operator (RTO) may call an event where customers signed up for the program can benefit by reducing their electric load. The RTO will make reduction event payments and on going energy and demand incentive payments.

• Customers can reduce demand by using backup generation or by turning off lights, equipment, air conditioning, etc.

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Demand Response DriverBalancing supply and demand on the electricity grid is difficult and expensive. Demand Response is a cost-effective and reliable way to meet peak demand. The alternative is to build more generation and transmission for 1% of the year.

Annual Electricity Demand As a Percent of Available Capacity

50%

100%

Winter Spring Summer Fall

75%

25%

90%

>10% of infrastructure costs are spent to meet

peak demand that occurs less than 1% of

the time

Increase Revenues with Demand Response PJM Interconnection, LLC – City of Marietta’s Regional Transmission Operator

• PJM Manages the world’s largest electric grid.

• People served: 60 Million• States served: 13 & D.C. • Generating Capacity: 167 gigawatts• Peak demand (2011): 158,450 MW • DR capacity (2011): 11,824 MW • DR payments (since 2010):

$950,000,000+

PJM Statistics

Program Months June 1 through September 30

Electric Reduction Period

Weekdays Only, No Holidays 12pm to 8pm, Two hour event notice given

One Hour Test One Week notice given. Test data required if no event is called by August 15th

Recent Events Most recent events in Ohio: June 2012

Program Administered By:Thomas M. Bellish

President

22

Start End

Drop to Target = 48 kW

Goal – Drop to 48 kW

PLC = 458 kWPeak Load Capacity

Payment kW – 410 kW or the difference between your PLC and your Drop to Target

Demand Response Event for City of Marietta

Summary of Demand Response Benefits Environmental Benefits:• An Intelligent Demand Response Program improves energy efficiency.• Demand Response decreases air pollution and greenhouse gas emissions.• Demand Response is a clean alternative to building new power plants.• Demand Response can help identify and eliminate Phantom Loads.

Financial Benefits:• An Intelligent Demand Response Program

can identify and reduce Peak Demand Charges (Can average to be 15% to 40% of your electric bill)

• No out‐of‐pocket or up front costs to participate.

• Guaranteed Capacity Payments for the City of Marietta based on 410 kW of Curtailment Capacity:= $24,969 (for 3 year period)= $8,323 per year

The Benefits of Plant Tours: Sludge Handling West Central Conservancy District @ Avon, IN

Sludge Load Out Facility:• Sludge Load Out Facility was clean, highly

automated and requires very little maintenance.• The new centrifuges were installed in a building

that previously held their belt filter press in 2011.• Roll off containers can be placed and sludge

load out operations can and do run during the night when there are no personnel present!

• Marietta WWTP Phase 2 was modeled after the WCCD Sludge Load Out Facility.

Equipment Selection: Flotweg Centrifuges:• WCCD has two (2) Flottweg C5 Centrifuges.• WCCD Staff had high praises for Flottweg

Centrifuge Systems and services provided.• Flottweg has developed a Centrate Liquid

Recovery System that utilizes kinetic energy from the centrate and will save 15% energy costs.

• Marietta pre‐negotiated price and specified Flottweg as a sole source supplier.

Site Visit on May 30, 2013

Direct Load out of Sludge

• In Phase 2, the City chose to model and design their facility similar to WCCD to allow the direct load out of the dewatered sludge cake.

• The key benefit is less labor due to elimination of double handling of the dewatered sludge cake.

• Environmental benefits include less odor to the nearby commercial district from sludge operations and stored cake and less storm runoff.

Direct Sludge Load Out

• Insert photo here.

Benefits of Plant Tours: Bowling Green, OH WWTP

Re-circulation of Effluent:• Prior to 2008, potable water was used for all

required process related water.• The actual water & sewer bill in 2007 was

$66,870 per year.• After retrofitting to re‐circulate effluent for all

process related equipment, the annual water & sewer bills dropped to only $21,700 per year.

• Annual Savings = $45,170

Septage Receiving:• Ohio EPA offers reductions in interest rate for

Marietta’s Phase 3 Construction Loan such that the savings will pay for the as‐bid principal and interest costs of the septage receiving facilities.

• Additional Annual Revenues = $140,000 @ Bowling Green WWTP (Avg. 5.5 MGD) O&M Expense = Less than $5000 per year

Site Visit on January 30, 2013

Benefits of Plant Tours: Napolean, OH WWTPEnaqua Non-Contact UV Disinfection System

Equipment Selection Considerations:• UV vs. Sodium Hypochlorite vs. Chlorine Gas• Non Contact Tech. vs. Traditional Contact Tech.• Construction Advantages – No concrete channels

and no jib hoists or cranes required.• Flow & Level Pacing: Reduces Energy

Consumption and increases lamp life.• Heat Exchange System – Controls Temperature for

optimum UV Lamp output and performance.• Energy Efficiency: $13,346 for Enaqua EDS

vs. $34,528 for a Traditional Dimming System (This is an actual comparison based on PeakFlow=28 MGD, Avg.=6 MGD and $0.10 / kWh

• UV SCADA Built in – No costly integration & prog.• SMART Lamps – Low Pressure High Output (LPHO)

equipped with unique ID that monitors status, hours of run time, date installed, and UV intensity.

• Lamp Warranty – Full replacement to 12,000 hrs.• Low Maintenance Costs (self cleaning AFP Tubes)

Site Visit on January 31, 2013

Technologies in Comparison

ENAQUA AFPTM

NON-CONTACT TECHNOLOGYQUARTZ SLEEVE UVTRADITIONAL CONTACT TECHNOLOGY

50

0

37.5

25

12.5

mJ/cm2

Low cost high output lamps High cost amalgam lamps

No quartz sleeves Fragile quartz sleeves with risk of mercury and glass contamination

Fouling-resistant AFP™ tube Fouling-prone quartz sleeves

Turbulent flow provides self-cleaning of AFP™ tube

Cleaning system required

No AFP™ tube replacement under normal conditions

Quartz sleeves need to be replaced over time

Simple pipe hydraulics makes UV disinfection easy to predict

Channel hydraulics makes UV disinfection less predictable

No level control devices required Level control devices increase footprint

Energy efficient – Flow & Level Pacing

Improved lamp lifeImproved ballast life Reduces power consumption compared to “dimming” systems

Actual comparison of bid guaranteed UV energy costs for Wastewater Plant, Peak 28MGD, Average 6MGD, $0.10/kWh.

Annual Energy Cost Comparison

$ 13,346Enaqua EDS

$ 34,528TraditionalDimming Systems

Unique Flow & Level Pacing system only turns on lamps required to do the job

Flow & Level Pacing

INTELLIGENCE – UV SCADA built inFull system control and performance monitoring wherever and whenever you want

No special hardware and software requirementsSimple connection via web browserMultiple Levels of AccessRemote monitoring and control via InternetStand-alone WiFi control e.g. with iPad®, Android®, Windows® Tablets, PC’s or PhonesSCADA integration with ModBUS TCP/IPRemote troubleshootingEmail and text notification

iPad®, Android®, Windows® are registered trademarks of their respective owners.

SMART Lamps – Advanced lamp controlEnaqua’s Low Pressure High Output (LPHO) lamps are equipped with a unique ID for monitoring status, runtime, date installed and other key parameters.

Name:Alarm:Status:

Runtime:Current:

UV Intensity:Serial No:

Certification:First On:Last On:

On Cycles:Life:

Stage1-LR06-LN010NonePower: On, Lamp: On552:30:00 hrs1.09 amps96%5B69802112/13/1201/30/1327216000 Hours

UV Disinfection System Summary• The existing UV System at Marietta WWTP is a first

generation Traditional Contact (Quartz Sleeve) UV Disinfection System and is at‐risk in flood events.

• Bulbs are on all the time to reduce burn out of ballasts.

• The new system will be significantly more energy efficient.

• Despite having a higher peak flow capacity, the annual operating costs will be reduced with a present worth savings of approximately $302,000.

How Financing Your WWTP Project Loan can lead to Sustainability Opportunities.

Ohio EPA WRRSP Program

• The Purpose of the WRRSP Program ‐ Counter the loss of ecological function and biological diversity that jeopardizes the health of Ohio’s water resources.

• This program funds both preservation and restoration of aquatic habitat to accomplish this goal. (Give Examples)

• City of Marietta worked with Ohio Valley Conservation Coalition to accomplish two wetlands preservation projects.

Photo of the Keystone Furnace Wetlands Preserve which is currently a 700 acre Nature Sanctuary located in Jackson County, OH with plans to expand to 900 to 1000 acres in the near future.

Keystone Furnace Wetlands PreserveJackson County, OH

Environmental Benefits:• Direct Purchase of 308 Acres • Diverse Habitats including open water,

wooded wetlands, shrub swamp, and emergent wetlands.

• 90 Acres of Category 3 Wetlands (ORAM Score of 92.5 out of 100)

• Over 7000 Linear Feet of perennial stream.

• Site includes 15 State‐Listed species including 4 Endangered Species.

• EPA Requires an Environmental Covenant

Photo of the Keystone Furnace Wetlands Preserve showing the site’s vast wooded wetlands system.

Financial Benefits:• Interest Rate reduced from 3.08% to 3.00%• Savings to City = $46,690 based upon:

Phase 1 Loan Amount of $5,558,292 20 year term for loan repayment

To download a copy of Keystone Fact Sheet:http://www.mariettaoh.net/government/wastewater/reports

Trumball Wetlands ProjectAshtabula and Trumball County, OH

Environmental Benefits:• Direct Purchase of 465 Acres within the

Lake Erie Watershed• The Grand River Lowlands area has some of

Ohio’s highest quality wetlands • 380 Acres of exceptional & diverse Category

3 Wetlands (ORAM Score 96 out of 100)• Over 2,265 Linear Feet of Stream/Riparian

Protection. • Site includes several State‐Listed species

and an Ohio Endangered Species.• Land Owner’s other options – Gravel Mine

Photo of the Trumball Wetlands Project showing a nice view of the Large Oxbow Wetlands water moat that completely surrounds the aquatic mat.

Financial Benefits:• Interest Rate reduced from 2.45% to 2.35%• Savings to City = $73,238 based upon:

Phase 2 Loan Amount of $6,975,000 20 year term for loan repayment

To download a copy of Trumball Fact Sheet:http://www.mariettaoh.net/government/wastewater/reports

Dairy Wastes‐ A Significant Factor

• A local dairy discharged high strength carbon to the public sanitary sewer system that created a severe “bulking” problem in the bioreactor.

• Sludge Volume Index (SVI) readings in excess of 300 ml/g were common, and this impacted effective setting.

• The City got the dairy to install load leveling, but this was not enough.

• The reality of pushing the business too far was for it to leave town, which would have resulted in a loss of 100 jobs and tax revenue and was unacceptable. Thus, an innovative private‐public solution was sought.

Biological Selector

• The selector is a small pre‐mix activated sludge tank system that provides rapid contact of settled primary effluent or screened raw sewage and return activated sludge (RAS).

• The small size of this chamber creates a very high “food to micro‐organism (F/M) ratio,” which has been shown to be effective in controlling episodes of sludge bulking and foaming.

• Benefits of this new system to the existing plant include process stability and the ability to use less tanks and blower air for treatment.

• An illustration of the biological selector is provided below.

Biological Selector

Biological Selector‐ Findings

• The benefits derived from this improvement have confirmed that the system does work. The activated process is now more stable than in the past and had not experienced any severe outbreaks of bulking.

• Also, the plant can run fewer aeration tanks without loss of treatment. This has allowed the City to trim its blower use and save energy and a reduction to the carbon footprint.

• The selector has allowed the City more latitude to the dairy to increases its loads and expand product lines.

• In addition, the City of Marietta will be able to accept wastes from septic hand haulers, alleviating a non‐point source of pollution and generating additional revenue for the City.

Plant Wide SCADA

• The current WWTP has no overall control system.

• The Phase 3 project will include a plant wide SCADA.

• The principal purpose will be monitoring, reporting and control for data acquisition.

• It is hoped to eliminate the night shift through application of SCADA.

Any Questions or Comments?

Joseph R. Tucker, PECity Engineer

City of Marietta, OH

Dale E. Kocarek, PE, BCEEStantec Consulting Engineers

Columbus, OH

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