Florida Water Resources Journal - April 2016

News and Features4 Evaluating the Costs and Benefits of

Water Conservation Programs Using aWater Conservation Tracking ToolBill Christiansen

34 WEF HQ NewsletterEverett L. Gill andT. Houston Flippin

41 FSAWWA Membership Rewards47 Americans Want Public Officials to

Invest in Water Systems, are Willing toPay More for Safe Water Service

52 News Beat

Technical Articles6 The Next Generation of Data-Driven

Demand Management: Long-RangePlanning for Revenue StabilityGregoryM. Baird and Jeff Lipton

20 Where Wastewater Treatment Ends andDrinking Water Begins: Evaluating theViability of Potable Reuse in FloridaCharles W. Drake, Gary J. Revoir II, andDave MacNevin

28 Capacity Benefit Calculator Models CostSavings from Capital DefermentTonyaSimmons and Max A. Castaneda

42 Developing Potable Reuse for El Paso,Texas: The Most Direct ApproachChristopher Hill, Gilbert Trejo, GeorgeMaseeh, and Aide Zamarron

48 Potable Reuse: The Regulatory Contextfor Florida and the U.S.Katherine (Kati) Y. Bell and Allegra da Silva

Education and Training11 Florida Water Resources Conference19 CEU Challenge25 FSAWWA Fall Conference Call for Papers 26 FSAWWA ACE16 Luncheon31 FWPCOA Training Calendar39 TREEO Center Training54 FSAWWA Roy Likins Scholarship55 FWPCOA 2016 Short School

Columns10 Certification BoulevardRoy Pelletier32 FWRJ Committee ProfileFSAWWA

Contaminants Committee37 Reader ProfileJody Barksdale38 FWEA FocusBrian Wheeler40 Spotlight on SafetyDoug Prentiss Sr.46 C FactorScott Anaheim51 FSAWWA Speaking OutKim Kunihiro

Departments54 New Products56 Service Directories59 Classifieds62 Display Advertiser Index

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Volume 67 April 2016 Number 4

ON THE COVER: The City of Clermonts East SideWater Reclamation Facility can currently produce anaverage of 2.2 mil gal of reclaimed water each day.Reclaimed water is collected domestic wastewatertreated to very high standards and then redistributedfor use as irrigation water. Purple irrigation pipe hasbeen installed in many of the newer subdivisions toprovide them with reclaimed water in the future.(photo: Bob Reed, City of Clermont)

Florida Water Resources Journal April 2016 3

4 April 2016 Florida Water Resources Journal

Bill Christiansen

Selecting which water efficiency and con-servation programs to implement can be adaunting task, and there are many things to con-sider when doing so. What works in one servicearea may not work in another. The Alliance forWater Efficiencys Water Conservation TrackingTool is an Excel-based model that provides aframework to evaluate the costs and benefits ofwater efficiency and conservation programs. It isa resource that the Alliance for Water Efficiencyprovides for free to its members.

The tracking tool guides the user through alinear evaluation process using six data inputand seven data output worksheets.

Input Worksheets1. Common Assumptions 2. Specify Demands 3. Enter Utility Avoided Costs4. Define Activities5. Enter Annual Activity6. Greenhouse Gas (GHG) Module Inputs

Output worksheets1. Activity Savings Profiles2. Water Savings Summary3. Utility Revenues and Rates4. Utility Costs and Benefits5. Water Loss Comparison6. Customer Costs and Benefits7. GHG Reduction Benefits

Data inputs characterize the service areawith things like population and water demandforecasts, utility avoided-cost data, and conser-vation program cost and savings estimates. Out-puts include water savings, revenue impacts,benefitcost analyses from the utility and cus-tomer perspectives, and energy savings. A li-brary of predefined conservation and efficiencymeasures are included, but the user has the free-dom to design custom programs.

Service area water savings resulting fromnational and state plumbing codes can be esti-mated if the users forecast does not already in-clude those impacts. The tracking tool generatessavings estimates from the natural replacement

of toilets, showerheads, clothes washers, anddishwashers.

The tracking tool produces informationthat can be used to guide planning decisions,such as the costs and benefits of conservationprograms, but why are costs and benefits im-portant?

Before making an investment in conserva-tion and efficiency programs a utility can, andshould, weigh the benefits against the costs. Itsimportant to ensure that an investment in con-servation and efficiency will return a benefit thatexceeds the costs, and leave the ratepayers betteroff. For example, investments made to reducewater consumption can have a multitude ofbenefits that will lower utility costs and lessenthe need to increase rates in the future.

Example Water Conservation and EfficiencyProgram CostsS Incentives, such as rebatesS Staff timeS Marketing materialsS Other overheadS Possible customer costs

Example Water Conservation and EfficiencyProgram Benefits

Utility SideS Reduced short run avoided costsS Avoided, delayed, and/or downsized capacity

expansionS Reduced energy consumptionS Reduced GHG emissions

Customer SideS Lower utility bills in the short term (water,

sewer, electric, and gas)S Lower rate increases over the long term

Planning and evaluating water conservationand efficiency programs can help ensure that op-timal strategies are implemented. The trackingtool provides a comprehensive methodology tohelp in this process. More information and a linkto request a copy of the tracking tool can befound at http://www.allianceforwatereffi-ciency.org/Tracking-Tool.aspx.

Bill Christiansen is program manager at the Al-liance for Water Efficiency in Chicago. SS

Evaluating the Costs and Benefits of Water Conservation Programs Using

a Water Conservation Tracking Tool


The U.S. Water Industry

The water industry in the United States iscomplex and diverse. Each organization andmanagement structure is relatively unique,ranging from municipalities of single cities orcounties, to private utilities, to water districtsencompassing entire interstate regions. Nation-wide there are nearly 54,000 community watersystems1.

The industry doesnt employ any standardcommunication approaches with end users, aseach program is directed by varying officials andmanagers. As one of the most capital intensive2

($6.84 of investment to earn one dollar of rev-enue)3 sectors of cities (with water-related serv-ices twice as capital intensive as electricity andthree times as gas),4 and with historically lowwater prices and associated revenues, venturecapital and private equity have been reluctant todeploy capital to the water industry.5

The industry is also facing a near-term fu-ture of growing demand. From 2015 to 2019,the U.S. is projected to have a populationgrowth rate of 2.4 percent, with just under halfof the states with higher growth rates reachingup to 7.5 percent.6 Much of this growth is oc-curring in arid urban regions where the cost fornew water supplies is rapidly climbing, as tradi-tional supply sources have already been tapped.For water utilities, that means more customers,more water demand, and more infrastructuredevelopment needs.

In addition to new infrastructure, thecountry is facing a different crisis: replacing ex-isting infrastructure. In 2002, the U.S. Environ-mental Protection Agency (EPA) projected adaunting $335 billion gap to replace and updateAmericas entire aging water infrastructure inthe next 15 yearsand thats just for drinkingwater7; the estimate for underground water pipereplacement over the next 20 years (includingsewer and storm systems) is much, much larger.A recent U.S. Conference of Mayors estimateplaced a combined need for all assets, includinggrowth, at up to $4.8 trillion8. With over 240,000water main breaks in 2013 and an engineeringgrade of D from the American Society of CivilEngineers (ASCE)9 the U.S. wet infrastructure isat a critical crossroads, requiring this hiddenissue to become a public discussion at all levels.

Water Executives Facing New Realities

Amidst this backdrop of decreasing sup-plies, growing demand, and the need for mas-sive infrastructure investment, the U.S. waterindustry also finds itself at the dawn of a newrevolution of data-driven water managementpractices, definitions, and applications. Thistransformation builds on the evolution of waterresource supply and protection planning, whilefacing the current realities of asset failure due todeferred investments, population shifts, un-funded environmental mandates, utility knowl-

edge loss and skill shortages, water supply vari-ability, increased public scrutiny on utilityspending, changing financial markets, and con-tinued cost increases.

Misalignment of water supply and demandis one of the greatest environmental concernsfrom coast to coast, from the informed citizento the finance managers to the elected officialswith delegated oversight. The drivers of this dis-tress include climate change; populationgrowth; regulations; demand variability com-plicated by changing weather patterns andwater-saving efforts; wastewater reuse; and ex-changes, ownership, and transfers.

Water utility managers are expected toknow not only the per-capita demand of agrowing and changing population, but also howto protect existing customers from water short-ages due to natural or manmade emergencies,like contamination, drought, earthquakes, in-frastructure loss, fires, algae blooms, infesta-tions, and toxic spills.

Engineers are tasked with the evaluation ofinfrastructure needs, including replacement andrepair schedules. They must assess asset and ca-pacity needs, and, through master planning ef-forts, strive to achieve sustainability goals andbuild more resilient water systems.

Finance professionals are expected to under-stand the costs of these complex water issues andhow they will impact rates and revenues, while si-multaneously addressing the affordability con-cerns of the customer base. Even wastewaterutilities, which have historically been uncon-cerned with water supply issues, are now forcedto deal with the costly effects of lower flows fromwater demand management efforts, the complex-ities of reuse planning, and regulatory water qual-ity requirements, particularly in the wake of thelead-in-water disaster in Flint, Mich.

The Next Generation of Data-Driven Demand Management: Long-Range

Planning for Revenue StabilityGregory M. Baird and Jeff Lipton

Gregory M. Baird is president of WaterFinance Research Foundation in Salt LakeCity, and Jeff Lipton is director of marketingat WaterSmart Software in San Francisco.

F W R J


Its therefore unsurprising that utility fi-nance professionals do not like the notion ofconservation because the term has become syn-onymous with revenue loss, potential decreasesin credit ratings, and higher capital costs. Rev-enue erosion often leads to budget cuts that im-pair the ability to invest in preventivemaintenance programs to extend asset life. Re-duction in maintenance budgets leads to pre-mature asset failure that drives up capital costsagainst an ever-increasing list of deferred capi-tal projects, upgrades, infrastructure repairs,and replacements. This downward fiscal cycleresults in the inability to control or forecast rev-enue, and greater uncertainty concerning waterusage. In this context, conservation distorts theprice elasticity of demand and creates pressureto rebalance the fixed and volumetric compo-nents of water rates to help reduce revenue vari-ability.

This view of improved water use efficiency,however, is inherently flawed. In actuality, bet-ter control over water demand improves fore-casting capabilities and moderates variability.This creates greater financial control and im-proves both short- and long-term prospects formore efficient operations, greater customer en-gagement, and reduced future capital require-ments.

Controlled water demand reduction cre-ates growth capacity in assets by extending op-erating lifetimes. Controlled water demandmanagement also translates into trenchless re-habilitation of underground infrastructurewhen there is decreased throughput. This en-ables the utility to replace assets at lower cost,which is then passed on to customers in theform of more gradual rate increases. This holis-tic approach also accounts for the full life cycleof assets and infrastructure funding.

Focusing on Water Demand

Where do utilities turn for more waterwhen wells and rivers have dried up due to dan-gerously low aquifer levels and record low pre-cipitation? Historically, when utilities neededmore water, dams and reservoirs were con-structed and new wells were dug deeper. Theseapproaches are no longer viable in many partsof the country where water providers are facinghistorically low water levels in rivers andaquifers, as well as decreased surface runoff.10

Recycled and desalinated water are increasinglybeing pursued, but these projects take years ordecades to develop, are incredibly expensive,and only address a modest portion of supplyneeds.

New forecasting models incorporate con-trolled demand management and capture the

data of all water chain inputs, outputs, andstakeholders water use actions. The long-termresult is envisioned to include a dynamic andholistic data-driven picture that supports im-proved asset allocation and decision making.Such capabilities are expected to help save en-ergy, improve dynamic pricing ability, monitorwater quality, extend infrastructure longevity,and reduce capital expenditures by managingpeak demand."11

The Benefits of Water Demand Management

When considering updating or replacingcurrent water treatment plant infrastructure,demand reduction is a high-value alternative toprocuring new water supply resources. In addi-tion to helping balance mismatches in supplyand demand, short-term benefits of demand re-duction include:S Lower operations and maintenance costs S Lower energy expenses S Lower treatment costsS Deferred or downsized capital projects S Less rate shock S Higher credit scores S Reduced-rate loans for infrastructure proj-

ectsS Greater system reliability

Short-term demand reduction is usuallyassociated with drought, natural disasters, andeconomic crises, where real results are neededas quickly as possible; however, improved wateruse efficiency as a supply resource moves be-yond these conditions to offer substantial long-term benefits as well.

Water use reductions over a 20-year timehorizon can help optimize demand manage-ment policies, while creating new virtual watersupplies. These approaches have been shown to

have significantly slowed down rate hikes insome utilities12 and have yielded substantialavoided operational and capital costs. Addition-ally, investments in water use efficiency have im-proved demand forecasting and increasedrevenue control.13

Because of these and many other benefits,utilities across the nation (and the world) are in-vesting in demand management, with a generaltrend toward assigning these responsibilities towater conservation managers and teams. Si-multaneously, there is an increase in the numberof organizations calling for improved water ef-ficiency as a cost-effective source of supply, suchas the Alliance for Water Efficiency, Waterwise,and the California Urban Water ConservationCouncil. Even when demand reduction is not aspecific agency need, utility managers are in-creasingly honing in on demand managementbest practices as an integral component of theirresource management plans.

Infrastructure Cost Savings: A Colorado Case Study

Improved demand management helps re-duce operational and capital costs and allowsutilities to more easily fund current and futureprojects without an exaggerated rate shock,while concurrently mitigating affordability is-sues. According to a recent study in Colorado14,utilities were able to significantly downsize rateincreases through demand reduction practices.The study analyzed water use behavior and util-ity policies since 1980, projecting out utilitycosts to the present day had demand reductionsnever been introduced. The results were star-tling.

According to the City of Westminstersfindings, an additional 7,295 acre-ft would havebeen needed to meet rising demand. As new

Continued on page 8


water sources in the Colorado Front Range arepriced at an astonishing $30,000 per acre-ft, thecity calculated savings in capital investments tobe nearly $219 million. Demand reductionsparticularly affected peak-season water pro-duction, saving the city approximately $130million in additional treatment costs. Waste-water treatment savings of roughly $20 millionwere also realized.

Overall, through consistent demand man-agement programs, the City of Westminster wasable to avoid more than $591 million in costsfor new capital investments in water source sup-ply and infrastructure. The study also foundthat the utility saved, on average, $1.2 million inyearly operating costs.

The study also analyzed these costs andtheir repercussions on water and wastewaterrates, as well as tap fees. Combined water andsewer bills would be 91 percent higher than theyare currently, jumping from $655 to $1251 an-nually, had 1980 water usage levels continuedwithout demand management. Similar resultswere found for tap fees, where rates would haveincreased by 99 percent had conservation neverbeen introduced.

The report states that, Each water systemis unique, so the results from Westminster maynot be applicable to everyone. Utilities couldperform a similar analysis to see the real value ofconservation; however, the $590 million cost as-sociated with the additional 7,295 acre-ft of de-mand reveals the significant hardship associatedwith expanding water resources supply andwastewater treatment infrastructure in todaysenvironment.

Not only is it a hardship for the utility, butalso for the customer to keep up with rates thatare increasing at an alarming rate. As a recentarticle states, Water and wastewater rates haveincreased faster than the Consumer PriceIndex (CPI) over the past 15 years.15 Manag-ing the public response to rate increases hastaken on growing significance in recent yearsas utilities grapple with the double-edgedsword of rising infrastructure costs and de-creasing demands16 .

Although rates will still increase, they willdo so significantly more slowly when demandmanagement programs are in place. Utilities areincreasingly adopting rate structures that placemore weight on fixed costs, rather than variableoperating costs. Building demand-reductionprograms into the monthly fixed costs of utilitywater and wastewater rate structures allows util-ities to fully capitalize on all avoided water costs,as well stabilize revenues by emphasizing pre-dictable fixed costs.

Continued from page 7


The Cost of Reducing WaterDemand Versus New Water Sources

The best practices section of Californiasupdated 2014 water plan discusses a way to max-imize investments in data collection throughutility- and customer-side analytics technologies:

"In addition to using conservation ratestructures to incentivize water conservation,some water suppliers are using a new behav-ioral approach to affect demand management.Based on insights from psychological research,behavioral water efficiency programs informconsumers of prevailing social norms, such asthe average water use of neighbors, to driveconformity to a more efficient standard. Thiscomparison creates a social framework inwhich water conservation is seen as highly val-ued by residents of a community.

The effectiveness of behavioral water effi-ciency programs has been tested in several com-munities, including in an East Bay MunicipalUtility District pilot project run by WaterSmartSoftware, a technology startup. In this pilot, res-idents received water reports with informationabout their water consumption, the consump-tion of similar households, and personalizedrecommendations on ways to save. The yearlongpilot project involved 10,000 homes and a ran-domized control group.

Households that received water reports re-duced their water use from 4.6 to 6.6 percent,were more likely to participate in utility auditand rebate programs, and reported higher levelsof customer satisfaction.

The unit cost of saved water was between$250 and $590 per acre-ft, with a midpoint costof $380 per acre-ft.17

As outlined by the American Water WorksAssociation (AWWA) in its water resource man-ual, industry best practices for water use effi-ciency have included water surveys, residentialplumbing retrofits, system water audits, leak de-tection and repair, metering with commodityrates, native plant landscaping, high-efficiencywashing machines, low-flush toilets, and schooleducation programs. The costs for these con-servation or water efficiency programs rangefrom $465 to $980 per acre-ft and are only uti-lized by a small percentage of customers.

Because demand reduction has a cost and ayield, like any potential water resource, a thor-ough costbenefit analysis must be performedbefore implementing programs and AWWA of-fers a 10-step development process to do so. In-tegrating a demand management program aspart of a larger water management plan canprovide the best big-picture outlook on poten-

tial savings, avoided costs, and appropriatemeasures to benefit all stakeholders.

Improving Revenue Control

Water supply planners will not be able tomake prudent and cost-effective estimates andplans unless the customer water demand factorsbecome more accurate and consistent. Priceelasticity of demand is now distorted by con-servation messaging, which leads to more rev-enue uncertainty.

Revenue projections and rate studies usebilling information that is essentially meter con-sumption data combined with established rates.Improved data reliability and sophisticated in-terpretation is critical to improving forecasts andcapturing significant cost savings. This can bedone in part by avoiding higher-than-necessarypeaking factors and pipe sizes embedded in engi-neering assumptions. Infrastructure replacementplanning activities that incorporate an integratedinvestment planning process with more accuratedemand projections inevitably leads to lowerlong-term system costs. An integrated approachgrounded in data analytics and customer en-gagement connects the short-term revenue gapfrom demand management programs to longer-term, cost saving investment strategies.

This interconnected financial planningprocess establishes how rate increases requiredto cover revenue loss from conservation activitiesare offset by the long-term cost savings for in-frastructure repair and replacement programs.

A New Future

The application of data analytics in de-mand management, integrated with financialand infrastructure planning, embodies anemerging vision for water utility executives.From this new perspective, utility managers canengage all stakeholders by unifying various po-sitions and providing for a more data-rich com-munications environment. This data translatesinto insight and increasingly transparent boardand council meetings, more informed rate ap-proval processes, and empowered customers.

A more robust data environment means in-creasingly credible consumption and financialforecasts, greater stability of financial resources,and less costly access to capital. Utilities will beable to realize direct avoided costs, while creatingdata-driven justifications for new projects thatalign with actual consumption needs, informedthrough controlled demand management. Data-rich tools for demand reduction and control offeran economically viable and effective way to reachout to individual households. This approach ul-timately helps the utility of the future build a

partnership with customers that yields greaterconsumption management through informationtechnologies, data insights, and behavioral sci-ence that communicates the true value of water.

References

1 http://water.epa.gov/infrastructure/drinkingw-ater/pws/factoids.cfm

2 Baird, G.M., 2010. A Game Plan for AgingWater Infrastructure. Journal AWWA. 102:4:74

3 Mumm, J., Real Water Industry FinancialBenchmarks, 2015.https://www.linkedin.com/pulse/real-water-in-dustry-financial-benchmarks-jason-mumm?trk=prof-post

4 Wolff, Gary, and Hallstein, Eric. Beyond Priva-tization: Restructuring Water Systems to Im-prove Performance.http://www.pacinst.org/reports/beyond_priva-tization/

5 The U.S. Water Sector on the Verge of Transfor-mation: Global Cleantech Center white paper.http://www.ey.com/Publication/vwLUAssets/Cleantech_Water_Whitepaper/$FILE/Cleantech-Water-Whitepaper.pdf

6 http://en.wikipedia.org/wiki/List_of_U.S._states_by_population_growth_rate

7 U.S. Environmental Protection Agency 2007Drinking Water Infrastructure Needs Surveyand Assessment, presented March 2009.http://www.epa.gov/ogwdw000/needssurvey/index.html

8 http://www.usmayors.org/publications/201002-mwc-trends.pdf

9 http://www.infrastructurereportcard.org/a/#p/drinking-water/overview

10 Ground Water: A Critical Component of theNations Water Resources.http://www.ngwa.org/documents/positionpa-pers/sustainwhitepaper.pdf

11 The U.S. Water Sector on the Verge of Trans-formation: Global Cleantech Center whitepaper. http://www.ey.com/Publication/vwLU-Assets/Cleantech_Water_Whitepaper/$FILE/Cleantech-Water-Whitepaper.pdf

12 http://www.allianceforwaterefficiency.org/WorkArea/DownloadAsset.aspx?id=8671

13 http://www.awwa.org/store/productdetail.aspx?productid=39312060

14 http://www.allianceforwaterefficiency.org/WorkArea/DownloadAsset.aspx?id=8671

15 Beecher, J. (2013). Trends in Consumer Pricesfor Utilities through 2012. IPU Research Note.Michigan State University, East Lansing, Mich.

16 Goetz, M. 2013. Invisible Peril: Managing RateIssues Through Public Involvement. JournalAWWA, August 2013, Vol 105, No. 8, pp. 34-37

17 http://www.waterplan.water.ca.gov/docs/cwpu2013/Final/Vol3_Ch03_UrbanWUE.pdf SS


1. What does hydrogen sulfide (H2S) smelllike at low concentrations?a. No smell b. Chlorinec. Rotten eggs d. Sulfuric acid

2. What does the unit parts per mil (ppm)mean?a. 1 lb per mil lbsb. 1 gal per mil galc. 8.34 lbs per mil gald. 1 milligram per litere. All of the above.

3. Why doesnt scum sink to the bottom of aclarifier?a. Because its specific gravity is greater

than water.b. It is mainly inorganic material.c. Because its specific gravity is less than

water.d. Scum does sink to the floor of a

clarifier.

4. What adjustment should be made ifsolids are rising in a secondary clarifieraccompanied by small gas bubbles withvery little odor?a. Increase aeration dissolved oxygen (DO)b. Decrease the return activated sludge

(RAS) ratec. Decrease the waste activated sludge

(WAS) rated. Decrease aeration DO

5. Which activated sludge growth phase isconsidered to have the highest food-to-mass or food-to-microorganism (F/M)ratio, the lowest solids retention time(SRT), the highest sludge yield, and thebest oxygen utilization efficiency?a. High-rate aerationb. Extended aerationc. Conventional aerationd. Log growth

6. What happens to the alkalinity in wastewaterduring the denitrification process?a. It increasesb. It decreasesc. It does not changed. It stabilizes at 200 mg/l

7. What is the equivalent in gal per minute(gpm) of a pipe that has 1 mil gal per day(mgd) flowing through it? a. 694 gpm b. 1,440 gpmc. 133,690 gpm d. 7.48 gpm

8. Given the following data, what is thespecific oxygen utilization rate (SOUR) inan aerobic digester? OUR test starting DO is 6.9 mg/L OUR test ending DO is 4.2 mg/L OUR test time is 10 minutes Digested sludge total solids (TS)

concentration is 1.7 percenta. 2.1 mg/hour/gm TSb. 0.95 mg/hour/gm TSc. 1.64 mg/hour/gm TSd. 9.5 mg/hour/gm TS

9. What two laboratory analyses arenecessary to calculate the F/M ratio?a. Aeration mixed liquor volatile

suspended solids (MLVSS) andinfluent carbonaceous biochemicaloxygen demand (CBOD5)

b. Aeration mixed liquor suspendedsolids (MLSS) and OUR

c. Aeration MLVSS and effluent CBOD5d. Aeration MLSS and influent CBOD5

10. What is most likely to occur in an aerobicdigester when the air is turned off forcertain periods each day?a. Nitrates are increased, the pH

decreases, and the volatile solidsreduction worsens.

b. Nitrates are decreased, the pH increases,and volatile solids reduction improves.

c. Air rates do not have an effect onnitrates, pH, or volatile solidsreduction in an aerobic digester.

d. Nitrates are increased and alkalinity isdecreased.

Answers on page 46

Readers are welcome to submitquestions or exercises on water or wastewater treatment plantoperations for publication inCertification Boulevard. Sendyour question (with the answer) or your exercise (with the solution) by email to:[email protected], or by mail to:

Roy PelletierWastewater Project Consultant

City of Orlando Public Works DepartmentEnvironmental Services

Wastewater Division5100 L.B. McLeod Road

Orlando, FL 32811407-716-2971

Certification Boulevard

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Members of the Florida Water &Pollution Control Association (FWPCOA)may earn continuing education unitsthrough the CEU Challenge! Answer thequestions published on this page, basedon the technical articles in this monthsissue. Circle the letter of each correctanswer. There is only one correct answerto each question! Answer 80 percent ofthe questions on any article correctly toearn 0.1 CEU for your license. Retestsare available.

This months editorial theme isConservation and Reuse. Look aboveeach set of questions to see if it is forwater operators (DW), distributionsystem operators (DS), or wastewateroperators (WW). Mail the completedpage (or a photocopy) to: FloridaEnvironmental Professionals Training,P.O. Box 33119, Palm Beach Gardens,FL 33420-3119. Enclose $15 for eachset of questions you choose to answer(make checks payable to FWPCOA). YouMUST be an FWPCOA member beforeyou can submit your answers!

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1. Approximately ______ mil gal per day (mgd) ofBustamante effluent will be available as advancedpurified water treatment plant (APWTP) sourcewater during irrigation season.

a. 39.0b. 29.2c. 10.0d. 7.8

2. The rationale for establishing corrosion controlcriteria for the advanced purified water plant isthat corrosion control assists with

a. Lead and Copper Rule compliance.b. disinfection.c. odor control.d. avoiding source blending issues.

3. Which of the following candidate treatment trainprocesses is at least 25 percent effective in remov-ing all targeted constituents?

a. Chlorinationb. Ultraviolet and advanced oxidation processes

(UV AOP)c. Filtrationd. Nanofiltration and reverse osmosis (NF/RO)

4. A side stream from the Bustamante clarifierswill be treated with _______________ to re-move nitrate.

a. activated carbonb. biofiltrationc. chlorinationd. denitrification filters

5. El Paso Water Utilities (EPWU) recognizedwhich of the following factors in its decision topursue direct potable reuse as opposed to indi-rect potable reuse?

a. Local geological conditionsb. High-quality wastewater plant effluentc. Low-quality surface water sourcesd. Compatibility of drinking water and waste-

water quality

Developing Potable Reusefor El Paso, Texas:

The Most Direct Approach

Operators: Take the CEU Challenge!

Katherine (Kati) Bell and Allegra da Silva

(Article 2: CEU = 0.1 DS/DW/WW)

1. According to the authors, direct potablereuse is

a. not currently allowed in Florida.b. currently allowed in Florida.c. not currently allowed in Texas.d. widely practiced in Florida.

2. The regulation governing reuse inFlorida is

a. Chapter 62-602, FloridaAdministrative Code.

b. Chapter 62-610, FloridaAdministrative Code.

c. Chapter 62-699, FloridaAdministrative Code.

d. the Florida Forever Act.

3. United States utilities that have alreadyimplemented direct potable reuse havedone so according to the_______________ model.

a. ozone-biological activated carbon(BAC)

b. ultrafiltration (UF) chlorinec. full advanced treatmentd. intermediate advanced treatment

4. Since 2007, Florida reuse flows andratios have

a. increased.b. decreased.c. leveled off.d. not been recorded.

5. Less expensive alternative treatmentprocesses may be suitablewhen_____________ reduction is notnecessary.

a. fecal coliformb. suspended solidsc. total dissolved solidsd. nitrate

Potable Reuse: TheRegulatory Context for

Florida and the U.S.


Floridas Challenges

As Floridas population continues togrow, along with demand for additional watersupply and concerns regarding surface waternutrient changes, the state will face an in-creasing need for innovative water supplysource and management solutions, which will,in some cases, include potable reuse. Over thelast 50 years, municipal water treatment hasadvanced in response to an increased under-standing of the importance of water quality topublic health, and water quantity to meet in-creasing challenges placed on the states re-sources by a population that has more thantripled, from 5.7 million in 1964 to more than

19 million in 2014. In that year, Floridiansused more than 2,300 mil gal per day (mgd)of potable water. In fact, most of the statespopulation lives inside a water resource cau-tion area.

In 2013, Floridians generated over 1,603mgd of sewerage flow to wastewater treatmentfacilities. Florida leads the nation in reuse ofwastewater, capturing over 44 percent of theflow (719 mgd) for beneficial reuse. Thismeans that most of the states wastewater isstill lost as a resource, presenting the oppor-tunity for potable reuse to take advantage ofthe wastewater that is not beneficially reused.Increasing concerns about nutrient dischargesand saltwater intrusion have placed an em-

phasis on recovering more benefit from theuntapped 56 percent of wastewater flow.

In the past ten years, at least seven com-munities have pilot-tested potable reuse tech-nology. Many of these communities weredriven by the Ocean Outfall Rule, which willcome into effect within the next 10 years;other communities were driven by concernsabout limited alternative water supplies, likebrackish reverse osmosis (RO), minimumflows and levels (MFL), or other regulatory is-sues. The new challenges Florida is facing areleading to a historically unprecedented tran-sition that will change the way water is used.

This article discusses the positive impactof potable reuse on Floridas water future, con-sidering seven recent potable reuse pilots, costcomparisons of alternative water supply (AWS)treatment methods, and a concluding discus-sion on the prospects of direct potable reuse(DPR), which is a technically and financially vi-able option that will help to enhance the statesapproach to integrated water management.While other less costly water management al-ternatives (e.g., rapid infiltration basins, non-potable salt water intrusion barriers, etc.) mayexist in some circumstances, the financial via-bility of potable reuse is expected to improvefurther, with future innovations and increasedregulatory drivers to eliminate surface waterdischarges, driving its adoption across the state.

Florida Potable Reuse Pilot Studies

Summary of Pilot Studies and Treatment Results

Within the past 10 years, several Floridacommunities have undertaken pilot studies ofpotable reuse, including Sunrise, Plantation,

Where Wastewater Treatment Ends and Drinking Water Begins: Evaluating the Viability of Potable Reuse in Florida

Charles W. Drake, Gary J. Revoir II, and Dave MacNevin

Charles W. Drake, P.G., C.P.G., and Gary J.Revoir II, P.E., are vice presidents with TetraTech Inc. in Orlando, and Dave MacNevin,P.E. Ph.D., is a project engineer with TetraTech Inc. in Tampa.

F W R J

Figure 1. Seven Recent Florida Potable Reuse Pilots


Miami-Dade County, Davie, Pembroke Pines,Hollywood, and Clearwater. All of these stud-ies were examples of indirect potable reuse(IPR), where purified water would be returnedto the surficial aquifer or a deeper brackishaquifer. Six out of seven of these pilot studieswere conducted in southeast Florida and drivenby the pending Ocean Outfall Rule, which callsfor reductions in nutrient discharges by 2018and elimination of ocean outfall discharges by2025 (except for peak flows). Collectively, theresults of these pilot studies demonstrate thatpotable reuse is a technically viable water sup-ply enhancement option for Florida.

Figure 1 provides a timeline of thepotable reuse pilots, beginning with Sunrise in2007 and continuing through the most recentpilot study, Clearwater, in 2014; the treatmenttrain utilized for each treatment process is alsoshown. It should be noted that all of the pilotstudies, except Hollywood, utilized the full ad-vanced treatment (FAT) train, consisting ofmicrofiltration/ultrafiltration (MF/UF), RO,and ultraviolet advanced oxidation (UV AOP).Hollywood tested multiple non-FAT-basedtreatment trains, as indicated by the ozone andUV AOP trains shown in Figure 1. Unlike theother treatment trains, Hollywood includedthe planned recharge into a brackish aquiferwith >3,000 mg/L total dissolved solids (TDS).

Notably, all seven treatment trainsdemonstrated the ability to consistently pro-duce water that exceeds the Flroida Depart-ment of Environemntal Protection (FDEP)primary and secondary drinking water stan-dards. Treatment requirements for groundwa-ter recharge (IDR) are summarized in F.A.C.62-610.563. As of early 2016, the City of Clear-water is taking the next step in its groundwa-ter recharge program by designing the firstfull-scale FAT potable reuse process in Florida(3 mgd).

Nutrients are part of the reason the FATtrain was considered for the other southeastFlorida utilities. The RO was necessary toachieve a total phosphorus concentraton of


ment train. In California, NDMA is subject toa 10 ng/L notification level. The standardmethod to reduce NDMA is through UV pho-tolysis. Atenolol was observed in one of theFAT treatment trains when peroxide wasfound to be temporarily underfed at the UVAOP (Mercer et al, 2015). Chlorate was alsofound in one of the FAT treatment trains andmay be a byproduct of sodium hypochloriteaddition. Its also worth noting that the com-pounds that pass through the RO treatmentprocess, including Bisphenol A (BPA), tris(1,3-dichloro-2-propyl) phosphate (TDCPP),triclosan, and trimethoprim, are different thanthe compounds observed in the non-FATprocess before granular activted carbon(atrazine, carbamazepine, gemfibrozil,naproxen, and sulfamethoxazole). Note thatthese constituents were then removed belowdetection limit by UV AOP or biologically ac-tivated carbon (BAC).

While not shown in Figure 2, it should benoted that total nitrogen and trihalomethanes(THMs) are two substances that can often passthrough potable reuse treatment processes dueto their low molecular weight and low/no mo-lecular charge. Utilities should keep these con-stituents in mind when planning potablereuse, especially DPR, and take appropriate

measures to mitigate prevent formation ofthese compounds or increase removal as ap-propriate (Mercer et al, 2015).

Mitigating the Potential for Arsenic ReleaseThrough Post-Treatment

Arsenic release emerged as a major con-cern in Florida aquifer storage and recovery(ASR) operations, especially after the arsenicmaximum contaminant level (MCL) was re-duced to 10 g/L. Like ASR, IPR consists of in-troducing a treated water into groundwater,and therefore has similar potential to inducearsenic release if certain post-treatment of thepurified water is not provided. Post-treatmentwas only demonstrated at two of the sevenpilot studies: Pembroke Pines and Clearwater.Pembroke Pines conducted extensive side-stream/bench scale testing of remineralizationfor the purified FAT water (Bloetscher et al,2013). Clearwater conducted extensive pilot-scale testing and rock-core leaching tests toidentify the impacts of remineralization anddissolved oxygen removal on mobilization ofarsenic and other trace metals (Mercer et al,2015).

Post-treatment is important for IPR tominimize impacts in aquifer recharge projectsand protect the injected purified water fromleaching of naturally occurring trace metals,

such as arsenic and molybdenum. Figure 3 il-lustrates the composition of a rock sampletaken from the Floridan aquifer in Clearwater,which is primarily composed of a calcium-based (limestone/dolomite) mineral with in-terspersed iron sulfide (pyrite) particles.Arsenic is concentrated within the pyrite min-erals and in the limestone matrix. Therefore,in selecting post-treatment in Florida for IPR(groundwater recharge), it is important to un-derstand the concentration of arsenopyrite,and if present, to provide calcium carbonatestabilization to remove oxidants in order tokeep iron sulfide stable by preventing oxida-tion to iron sulfate. In the case of the Clear-water pilot, calcium carbonate stabilizationwas provided through addition of carbondioxide and a hydrated lime slurry. Oxidantremoval was accomplished through mem-brane degasification, which removed dissolvedoxygen down to ppb levels and throughsodium hydrosulfide (NaHS) adition, whichquenched monochloramine instantly, and per-oxide over several minutes (Mercer et al,2015).

Cost of Potable Reuse AmongOther Water Supply Options

The ultimate factor driving the adoptionof potable reuse in Florida will be its cost rel-ative to other alternative water supplies, andcost avoidance of other integrated water man-agement projects in the context of the utilityregulatory environment. Multiple recent re-ports have indicated that potable reuse can bea financially viable water supply/managementoption. Potable reuse will ultimately thrivewherever the incremental life cycle costs ofimplementing potable reuse are lower thanany other feasible option; that is, when potablereuse represents the next cheapest source ofwater supply for a utility/or next cheapest ap-proach to integrated water management. Dur-ing the recent drought years across the UnitedStates, several utilities in Texas reached thispoint, where potable reuse was a more cost-ef-fective option than importing water throughpipelines. A similar situation exists in much ofSouthern California, where no more water isavailable to import and seawater desalinationis slow to permit and costly to implement. Thefirst IPR processes were implemented in Cali-fornia as seawater intrusion barriers used toprotect existing groundwater supplies thatwere being overdrawn. Failing to implementIPR (with saltwater intrusion barriers), whilemaintaining overdrafts of water, would havemeant the eventual loss of a valued ground-water resource.

Figure 3. Elemental Analysis From a Scanning Electron Micrograph of a Rock Sample From the Floridan Aquifer, Indicating the Need for Post-Treatment.

(Adapted from Image Courtesy: Indewater, Florida Geological Survey)


Florida is in excellent standing comparedto these other states in that there is not yet asevere crisis of water shortages. Therefore, ithas been able to take an aggressive, plannedapproach to the implementation of potablereuse, among many other integrated watermanagement tools. This thoughtful planningapproach is exemplified by the recent SenateBill 536, Report on Expansion of BeneficialUse of Reclaimed Water, Stormwater, and Ex-cess Surface Water (FDEP 2015), and thestatutorily mandated water supply planningby each of the states water management dis-tricts.

Traditionally in Florida, brackish ground-water treated with RO has been the alternativewater supply of choice, and there are concernsin some areas that even the brackish ground-water supplies are being tapped near sustain-able limits, manifested by increases in brackishwater TDS over time. As of 2010, brackishwater RO made up approximately 7 percent(165 mgd) of the states total public potablesupply, which is 2,300 mgd (USGS, 2014). In asituation where traditional groundwater sup-plies are fully utilized, and brackish RO is ei-ther fully utilized, or unavailable, Floridautilities can consider the following: purchas-ing water from their neighbors, surface watertreatment (if available), potable reuse, or sea-water desalination (considering the costs). Inaddition, as exemplified by the Ocean OutfallRule and Numeric Nutrient Criteria, the dis-charge of treated wastewater to the environ-ment has come under increasing scrutiny,which, in the case of several southeast Floridautilities, means a requirement to beneficiallyreuse a large portion of the wastewater thatwould have been released to tide.

A number of recent reports have shownthat potable reuse can be a financially viableand cost-competitive water supply alternative.Despite the potential for differing assump-tions behind the different cost estimates, thereis a notable consistency in costs amongsources. A review of water supply options inCalifornia (Tchobanoglous, 2014) indicatedthat both IPR and DPR would generally becheaper than seawater desalination, and insome cases, be cost-competitive with brackishgroundwater desalination or imported water.The WateReuse Associations recent Frame-work for Direct Potable Reuse (Figure 4) in-dicated that seawater desalination costs inCalifornia far exceeded the cost of potablereuse and brackish groundwater supplies(Tchobanoglous et al, 2015).

Looking at estimated costs withinFlorida, a recent report from the St. JohnsRiver Water Management District (SJRWMD,

2014) evaluated costs for direct potableaquifer recharge ($3.11-$3.69/kgal) IPR anddirect reuse ($3.85-$3.91) DPR (Figure 5)within the range of costs (~$2.25-$6.00/kgal)for IPR/DPR (Tchobanoglous, 2014). All threestudies indicated seawater desalination as themost costly water supply option.

Saltwater intrusion barriers, such as the2-mgd Southern Hillsborough Aquifer

Recharge Program (SHARP), are a lower-costaquifer recharge option. The lower cost is dueto the limited treatment requirement for prin-cipal treatment and disinfection, as long as thetarget aquifer is between 1,000 mg/L and 3,000mg/L and the target aquifer is not to be usedas a drinking water source (F.A.C. 62-610.563[2]).

Figure 5. Life Cycle Cost ($/kgal) of Water Supply Alternatives Within the St. Johns River Water Management District

(Source: SJRWMD, 2014)

Figure 4. Range of Life Cycle Cost of Water Supply Alternatives in California (Source: Tchobanoglous et al, 2015)


Continued on page 24


Looking at the estimated cost of variouslevels of treatment at the Hollywood project(VanEyk et al, 2014), projected life cycle costsrange from $2.15/kgal for an alternative treat-ment train (Alternative 2b, two-stage IX,ozone, BAC, and UV disinfection) to$3.84/kgal for a FAT treatment train. It shouldbe noted that the alternative non-FAT treat-ment scheme, as piloted at Hollywood, wouldrequire a waiver from Broward County forTDS, chemical oxygen demand (COD), chlo-ride, sodium, and phosphates; however, theredid not appear to be any allowance in the Hol-lywood costs for post-treatment to mitigatearsenic release. Nevertheless, these data illus-trate a consistency with the other cost estimatesources.

Notably, since many of the southeastFlorida pilot studies have taken place, moreutilities, such as Miami-Dade, that were con-sidering discharge to the surficial aquifer, arenow rethinking that approach and planning torecharge deeper brackish aquifers because ofreduced costs. By switching from a BiscayneAquifer (fresh) recharge ($10.40/gpd capitalcost) project to a Floridan aquifer (brackish)recharge project ($2.78/gpd capital cost),Miami Dade County anticipates a significantreduction in the capital cost to construct itsreuse management option. With the Floridanaquifer recharge option, Miami-Dade antici-pates that a waiver on total nitrogen (TN) lim-its to the Floridan aquifer will be required.While these costs do not take into account thepotential nutrient removal benefit of potablereuse, if the value of a two-for-one water sup-ply/nutrient removal treatment were consid-ered, potable reuse may be a lower life cyclecost option than other water supply alterna-tives.

Besides being cost-competitive, potablereuse offers several potential benefits toFlorida utilities: it can protect environmentalresources by significantly reducing surfacewater discharges (IPR via groundwaterrecharge) and even discharges to groundwater(DPR), it is attractive as a drought-proof water supply that is not subject to seasonallimitations, and a utility may also choosepotable reuse to obtain control over its ownwater supply and reduce purchases of im-ported water.

The Challenge of Effective Potable Reuse Operations

Identifying and Sharing Operational LessonsLearned is Key

An important but often under-discussed

aspect of successful potable reuse processes isoperations. Much attention has been given topotable reuse treatment technology and re-moval of contaminants; however, an equallyimportant concern is how to maintain effec-tive treatment while managing inevitableprocess upsets, especially with DPR. Potablereuse processes can be unfamiliar to many op-erators and therefore pose new challenges tomaintaining stable operations. Potable reuseoperations often focus on critical controlpoints, which are process targets that can bemeasured to provide assurance that the in-tegrity of the purification processes is beingmaintained. The WateReuse Research Foun-dation is pursuing multiple projects to addressthis issue, including Development of Opera-tions and Maintenance Plan and Training andCertification Framework for DPR Systems(WRRF-13-13).

There are several potential operationalchallenges that can be encountered while run-ning a potable reuse process, including UFmembrane cleaning, UF membrane fiberbreaks, variable ammonia/nitrogen loads, con-trol of THMs, control of TN, RO membranefouling, protecting RO membranes from chlo-rine damage, monitoring and maintaining UVlamps and peroxide, chemical dosing and ki-netics of chlorine and peroxide quenching,dissolved oxygen removal and arsenic release,and dosing of calcium stabilization chemicals(Mercer et al, 2015). Sharing of best practicesand operational lessons learned will be crucialas more Florida utilities begin implementationof potable reuse.

Operator Certification and TrainingAnother uncertainty introduced by

potable reuse processes is how to structure op-erator licensing for potable reuse treatmentprocesses. The FDEPs current operator li-censing system includes classifications forwater operators and wastewater operators;however, the future classification and creden-tials of a potable reuse treatment plant opera-tor is less well-defined. Training materials andcourses will need to be developed to provideoperators with the education needed to oper-ate the new processes involved in potablereuse; the DPR operations specialty certifica-tions could be appended to existing certifica-tions, requiring a blend of training andexperience hours (WRRF-13-13). One poten-tial approach could be to create an all-inclu-sive water treatment plant operator licensethat would include treating any type of Floridawater to potable standards. Other statutoryand regulatory changes will need to be dis-cussed and enacted.

Direct Potable Reuse

Florida, Texas, and CaliforniaTo date, none of the potable reuse pilot

systems in Florida have been tested for DPRand all pilots have been operated under the as-sumption of IPR. While Florida currently hasregulations for IPR through groundwaterrecharge and discharge to surface waters, thereis currently no Florida regulation to guide theimplementation of DPR. Historically, regula-tors have proceeded with extreme caution dueto the unknown long-term health effects oflow levels of organics and heavy metals. In ad-dition, because of the source of the water,there are concerns about the potential effectsof unknown or unidentified compounds. His-torical drought conditions and populationgrowth in Texas and California have led regu-lators to take more action to move the imple-mentation of DPR forward. Florida shouldconsider the example of other states and theimportance of process integrity monitoringwhen considering DPR.

Faced with the prospect of dry reservoirsin some communities, Texas has approved sev-eral communities for DPR on a case-by-casebasis, without implementing a single rule ap-plicable to all. Faced with a recent drought sit-uation, the City of Wichita Falls, Texas,implemented emergency DPR, transferringpurified water to its existing drinking watertreatment plants for further treatment andfinal distribution. With reservoir levels re-stored, the city returned to IPR via its localreservoir. At present, only Texas and NorthCarolina have regulations specifically address-ing DPR.

In contrast, California has taken a moremeasured approach, most notably through theCalifornia Direct Potable Reuse Initiativesponsored by the WateReuse Research Foun-dation and supported by multiple donors. Theinitiative is sponsoring several research proj-ects to develop monitoring tools to help mon-itor the integrity of each barrier in thepurification process. The California Depart-ment of Public Health (CDPH) was mandatedto complete its assessment of DPR and pro-vide a report to the California Legislature bythe end of 2016, recommending how the stateshould or should not proceed with DPR. Todate, the WateReuse Research Foundation hassponsored over 19 research projects looking atsome of the key barriers to implementing DPRand identifying solutions. What this means forFlorida utilities is that there is a rapidly in-creasing body of knowledge on DPR methodsthat will provide sound science to support de-cision making, and potentially, implementa-



tion of DPR as an alternative water supply inFlorida.

Moving Forward With Direct PotableReuse: Demonstration Testing of ProcessIntegrity Monitoring

Because DPR does not provide a months-or years-long travel time like IPR does in a tar-get aquifer or surface waterbody, process in-tegrity monitoring will be critical to achievinghigh reliability in operations of the process. Ef-fective process integrity monitoring tools canhelp utilities identify and respond to potentialproblems more quickly, minimizing what isknown as the response retention time. Com-pared to IPR, DPR may have potentially lowercosts due to the elimination of recharge wellsand associated post-treatment; however thepotential cost savings could be offset by the ad-ditional monitoring requirements for DPR.

Before any Florida utility proceeds with aDPR program, it would be advisable for thatutility to construct a demonstration facility tocollect important data for use in establishingregulations for the plant and identifying bestpractices for continuous on-line integrity

monitoring. Before developing uniform regu-lations for DPR, it is likely that the state willpermit the first few DPR projects on a case-by-case basis, referencing accepted standardsof practice.

Conclusion

As Floridas population continues togrow, along with demand for additional watersupply and concerns regarding nutrientcharges, the state will face an increasing needfor innovative water management solutions,which will, in some cases, include potablereuse, which is a technically viable process forFlorida that can be fiscally viable given indi-vidual utility circumstances.

The technical viability of potable reuse inFlorida has been demonstrated by seven recentpotable reuse pilot studies. The financial via-bility of potable reuse is well attested by mul-tiple sources, indicating that potable reuse isusually cost-competitive with brackishgroundwater desalination and is almost alwaysless expensive than seawater desalination. Ifthe added nutrient removal benefit of potable

reuse is valued, the fiscal viability of potablereuse may be even greater in some situations.Special consideration for post-treatment is re-quired in the case of groundwater recharge(IPR) to mitigate arsenic release. While mostpotable reuse projects in Florida have focusedon IPR, introduction of DPR will require care-ful demonstration studies showing howprocess integrity monitoring can effectivelyverify reliability of the treatment barriers.

The broad implementations of potablereuse face hurdles in fiscal viability, potablereuse operations, and concentratedisposal/management. Although potable reuseis not always the right solution, improvementsin technology, accumulation of operating ex-perience, and innovative approaches may helppotable reuse better overcome each of thesehurdles. While Florida has not yet faced thecritical water shortages experienced in Cali-fornia and Texas, as population growth putsan increasing demand on its water resources,potable reuse will be an important and viabletool that Florida utilities can use as a part oftheir integrated water management approach.



References

AECOM, 2011. Town of Davie: AdvancedWastewater Treatment for Aquifer Recharge andIndirect Potable Reuse Pilot Study: Design-Build Water and Wastewater System ExpansionFinal Report. Sept. 2011. (Davie - Data Source).

Bloetscher, F.; Stambaugh, D.; Hart, J.; Cooper,J.; Kennedy, K.; Burack, L.; Ruffini, A.; Cicala, A.;Cimenello, S. Evaluation Membrane Optionsfor Aquifer Recharge in Southeast Florida. IDAJournal, Fourth Quarter 2011. (Pembroke Pines- Data Source).

Bloetscher, F.; Stambaugh, D.; Hart, J.; Cooper,J.; Kennedy, K.; Sher, L.; Ruffini, A.; Cicala, A.;Cimenello, S. Use of Lime, Limestone, and KilnDust to Stabilize Reverse Osmosis TreatedWater. Journal of Water Reuse and Desalination,March 3, 2013, pp. 277-290.

FDEP, 2015. Report on Expansion of BeneficialUse of Reclaimed Water, Stormwater, and ExcessSurface Water (Senate Bill 536). Office of WaterPolicy, Florida Department of EnvironmentalProtection. 8/05/15 Draft.

Hazen and Sawyer, 2008. City of Plantation:

Final Report: Advanced Wastewater TreatmentPilot Project. April 2008. (Plantation DataSource).

Hazen and Sawyer, 2014. City of Hollywood:Effluent Recharge Treatment Pilot Study: FinalReport. Appendix I. March 2014. (Hollywood Data Source).

Mercer, T.; Bennett, J.; Fahey, R.; Moore, E.;MacNevin, D.; and Kinslow. J., 2015. Ground-water Replenishment Performance and Opera-tions: Lessons Learned During ClearwatersOne-Year Pilot. Florida Water Resources Jour-nal, March 2015. http://fwrj.com/techarti-cles/2.15%20tech%203.pdf. Accessed 3/1/2015.

MWH. 2008. City of Sunrise: Southwest Waste-water Treatment Facility Advanced WastewaterTreatment (AWT) and Reuse Pilot Testing Pro-gram: Final Report, May 2008. (Sunrise DataSource).

MWH. 2009. Biscayne Bay Coastal WetlandsRehydration Pilot Project: Water Quality Evalu-ation. Miami-Dade Water and Sewer Depart-ment. Tech Memo # 1, May 2009. (Miami Dade Data Source).

SJRWMD, 2014. Potable Reuse Investigation ofthe St. Johns River Water Management District:The Costs for Potable Reuse Alternatives. St.

Johns River Water Mangement District. Ac-cessed 10/8/15.

Tchobanoglous, G. 2014. Direct Potable Reuse:Current Projects and Activities. University ofMiami Net Zero Water Design Workshop,5/29/14.

Tchobanoglous, G.; Cotruvo, J.; Crook, J.; Mc-Donald, E.; Olivieri, A.; Salveson, A.; Trussel,R.S., 2015. Framework for Direct PotableReuse. WateReuse Assocation. Accessed9/14/15. https://www.watereuse.org/wp-con-tent/uploads/2015/09/14-20.pdf.

Tetra Tech. 2014. City of Clearwater: Ground-water Replenishment Program Pilot Treat-ment System: Testing Phase Summary Report.9/16/14. City of Clearwater, Fla. (Clearwater Data Source).

USGS, 2014. Water Withdrawals, Use, andTrends in Florida, 2010. Scientific InvestigationsReport 2014-5088.http://pubs.usgs.gov/sir/2014/5088/pdf/sir2014-5088.pdf. Accessed 12/2/14.

VanEyk, T.; Vadiveloo, E.; Cooke, P.; Page, J.;Stanford, B. 2014. Alternative Technologies forIndirect Potable Reuse in Florida. Paper, FloridaSection AWWA. Annual Conference, 2014.11/30/14. SS



Background

In 2012, Simmons Environmental Con-sulting (SEC) assisted the St. Johns RiverWater Management District (District) withthe development of the Florida AutomatedWater Conservation Estimation Tool (FAWCET), which estimates water conserva-tion potential across the District. It also esti-mates daily net benefits of implementingwater conservation best management practices(BMPs) from the customer and utility per-spectives by estimating daily avoidable coststhat are based on water savings to be achievedby implementing BMPs. Further, FAWCETuses property appraiser data (age and size ofhome, lot size, etc.) to identify BMPs that aremost appropriate at the parcel level.

Two crucial questions for the water con-servation analyst are: Which BMPs should Iimplement? and For each BMP, how manyimplementations should I do? The firstquestion is answered by ranking BMPs basedon their daily net benefits; the second ques-tion is answered by FAWCETs optimizationfeature, which generates a table of BMPs andthe number of implementations recom-mended for each BMP. Generally, this table isgenerated by first exhausting the number ofavailable implementations for the highest-ranked (based on daily net benefit) BMP,then the next highest-ranked BMP, and so

forth, until the user-defined objective func-tion is met. A common example of an objec-tive function would be to maximize watersavings within a monetary budget.

It is important to understand that FAWCET evaluates net benefits of BMPs irre-spective of an implementation schedule be-cause all costs and savings are calculated byFAWCET as daily unit costs (costs and savingsper day). From the first day that a BMP is im-plemented, water savings begin to accrue overthe life of the BMP. In other words, a BMPthat will save 100 gal per day (gpd) will save100 gpd on day one of its implementation andcontinue saving 100 gpd throughout its lifecycle (assuming savings do not decay).

After FAWCET has selected the optimalmix of BMPs for a particular parcel or serv-ice area, the next question the conservationanalyst should ask is When should I imple-ment these BMPs? This is a question thatcannot be answered by FAWCET and one thatcannot be answered without yearly projec-tions of utility demands with and withoutconservation, the former of which dependson a yearly BMP implementation schedule.Further, without yearly projections of supply,demand, and BMP implementation, waterconservation cannot be properly evaluated asan alternative to developing new capacity.

Economic benefits of conservation areexpressed in terms of costs that are avoidable

through BMP implementation. These bene-fits include cost savings attributed to reduced(by conservation) operation and mainte-nance (O&M) costs, and cost savings attrib-uted to deferring (or eliminating) the capitalcost of future (new or expanded) capacity.Cost savings attributed to deferring (or elim-inating) the capital cost of future (new or ex-panded) capacity is called the capacitybenefit of conservation. In 2014, the Districthired SEC to develop a stand-alone demon-stration model, called a Capacity Benefit Cal-culator, to demonstrate how FAWCET resultscould be used by conservation planners andanalysts to calculate the capacity benefit ofconservation. Intrinsic to this effort was thedemonstration of the need to develop anduse yearly projections of demand, supply, andBMP implementation to properly evaluateconservation as a supply alternative.

Capacity Benefit Calculator Models CostSavings from Capital Deferment

Tonya Simmons and Max A. Castaneda

Tonya Simmons, P.E., is a senior waterresources engineer with Greenman-PedersenInc. in Tampa and is the former president ofSimmons Environmental Consulting. Max A.Castaneda, MPAff, is an independent waterresources consultant in Jacksonville and wasformerly a water conservation expert with St.Johns River Water Management District.

SS F W R J

Figure 1. Model Inputs of the Capacity Benefit Calculator


This article describes model inputs andcalculations included in the calculator and theimpact that BMP implementation timing as-serts on the economic performance of conser-vation. Although not presented here (and notincluded in the model), avoidable O&M costs(another conservation benefit) are similarlysensitive to the timing of BMP implementation.

Inputs to the Capacity Benefit Calculator

Figure 1 includes a screenshot of modelinputs, which include the following sets ofvariables:

Economic PlanningS Period of Analysis (years) This is the pe-

riod over which the economic analysis willoccur. Typically, in Florida water manage-ment, 20 years is used.

S Discount Rate (percentage) The FederalWater Resources Discount Rate publishedyearly in the Federal Register is an appro-priate planning-level discount rate to use.

Water Supply and Demand ProjectionsS Demand at Year 0 (mil gal per day [mgd])

This is the utilitys water demand at

planning year 0 (one year prior to analy-sis start date).

S Demand at End of Period (mgd) If theperiod of analysis is 20 years, this inputwould be the utilitys demand at year 20.

S Current Capacity (mgd) This is the totalcurrent capacity of the water utility (sup-ply, treatment, and storage). Many utilitieshave various plants or storage facilitiesserving distinct zones in their overall serv-ice areas; in this case, demand and BMPimplementation should be evaluated at thezone level and current capacity should re-flect the capacity of the individual zones.

S Capital Cost of Next Increment of Supply This is the capital cost of building the nextincrement of supply, expressed in year-1constant dollars, which is the cost to buildnew or expand the existing water supply(withdrawal, treatment, and storage facili-ties).

Conservation Best Management PracticesYearly Implementation ScheduleS BMP Description The analyst would enter

each BMP here; FAWCET is an excellenttool to use to identify the best BMPs to im-plement for a utility service area.

S Water Savings Rate (WSR) The amount

of water saved by one implementation(i.e., retrofitting one fixture), expressed ingpd per implementation.

S NIt This is the number of BMP imple-mentations at each year, t. The user entersa number of implementations for eachBMP, and for each year. If FAWCET is usedto select BMPs, the analyst should con-sider using the FAWCET-recommendedtotal number of implementations for eachBMP. The task for the analyst is then toapply the total number of implementa-tions across the planning horizon in amanner that suits the utilitys conserva-tion budget or other planning goals.

Model Calculations and Outputs

Calculations and resulting outputs fromthe calculator are described as follows:

Conservation Best Management PracticesYearly Implementation Schedule

Using the number of BMPs imple-mented each year (NIt), the model calculatesthe cumulative number of implementationsper year (Cuml. NIt), as shown in Figure 1.



Best Management Practices Yearly Cumu-lative Water Savings

The calculator computes yearly BMP cu-mulative water savings (Cumulative WSt) atthe BMP level for each year of the planninghorizon (period of analysis) as follows:

Cumulative WSt = CumulativeNItWSR((365 days/year)(1,000gal/Kgal))

Where: Cumulative WSt = Cumulative water sav-

ings at year t, expressed in Kgal Cumulative NIt = Cumulative number of

planned implementations in year t WSR = Water savings rate expressed as gpd

per implementation

Note that in the preceding equation,yearly savings attributed to a BMP accumu-late over time. It is precisely this cumulativeeffect that necessitates evaluating BMPs andprograms temporally (implementations peryear over the period of analysis). Yearly cu-mulative water savings are shown in Figure 2.

Water Demand Projections and Capacity Deferment

The calculator uses analysis start-yearand end-year demands to calculate a constantdemand growth rate (displayed in the modeldirectly under the user-entered demands, asshown in Figure 1). The model uses thegrowth rate to calculate a linear yearly de-mand schedule with and without conserva-tion (Figure 2). This is an oversimplifiedapproach to projecting demands, but is pro-vided for ease of use. It is recommended in-stead that the analyst manually enter yearlydemand projections in the row Demandwithout Conservation (Figure 2).

The model calculates yearly demandwith conservation by subtracting programyearly cumulative water savings from De-mand without Conservation (Figure 2).

Based on demand projections with andwithout conservation, the calculator modelsprojected capacity deferment potential andanswers the following question: Can NewCapacity be Deferred? (Figure 2). The ca-pacity deferment potential for each year isdefined as:S Not needed = Demand without conserva-

tion is less than the current capacity.S Yes = Demand without conservation ex-

ceeds current capacity, but demand withconservation is less than current capacity,

meaning that the utility would not needthe new capacity in that year.

S No = Demand with conservation exceedscurrent capacity.

Capacity BenefitThe objective of the model is to calculate

the capacity benefit of conservation. The ca-pacity benefit is the final value calculated bythe model (bottom of Figure 2) and is calcu-lated as follows:

Capacity Benefit = PV of New Capacity with-out Conserv.-PV of New Capacity with Con-serv.

PVNew Capacity = Csupply (1+d)n

Where: PVNew Capacity = Present value (PV) cost of

next increment of supply (new capacity),expressed in analysis start-year constantdollars

CNew Capacity = Capital cost of the next incre-ment of supply (new capacity), expressedin analysis start-year (constant) dollars

d = Real discount rate n = Number of years new capacity is dis-

counted

The capital cost of the next increment ofsupply (CNew Capacity) and discount rate is thesame, irrespective of the BMP implementa-tion schedule. With respect to the capacitybenefit, the only difference between the PVwith conservation and the PV without con-servation is n, or the number of years thenew capacity is discounted. New capacity canbe deferred when conservation reduces de-mand ahead of the year that the new capacitywould be needed if conservation were notimplemented (or its effect was not sufficientto defer new capacity). Yearly demand withconservation is based on yearly cumulativewater savings, which are based on the yearlyBMP implementation schedule. As such, thecapacity benefit cannot be calculated withouta yearly BMP implementation schedule.

Using the Calculator to Demonstrate the Importance

of Yearly Projections in Conservation Planning

The impact of yearly implementationschedules was demonstrated by exploringtwo conservation plan scenarios using thecalculator. For both scenarios, every modelinput, including the total number of imple-mentations for each BMP, were held constant

and are the same as the inputs shown in Fig-ure 1. The only difference between the twoscenarios was the timing of BMP implemen-tation (the BMP implementation schedule).

In scenario 1, BMP implementationbegan at planning year 2, and was ratherfront loaded across the planning horizon,meaning the BMPs were planned for imple-mentation in the first 12 years and then dis-continued after year 12. For this scenario, thenext increment of supply was deferred threeyears, namely years 7, 8, and 9. This imple-mentation schedule resulted in a capacitybenefit of approximately $1.9 million.

In scenario 2, the total number of BMPsimplemented in the period of analysis wasthe same as for scenario 1; however, the totalnumber of BMPs was equally distributed overthe 20-year planning horizon. For this sce-nario, similar to scenario 1, the next incre-ment of supply was deferred at year 7;however, supply was deferred for year 7 only.This resulted in a capacity benefit of approx-imately $664,000.

Summary

Florida water conservation planningtools, such as FAWCET, do a fine job of an-swering the following question: WhichBMPs should I implement? Some tools, in-cluding FAWCET, answer this question forthe analyst by ranking BMPs by their unitcosts ($/Kgal saved) or, as in the case of FAW-CET, by daily net savings. However, FAWCET,and most other Florida-based tools, do notanswer this question: When should I imple-ment the BMPs?

The Capacity Benefit Calculator helpsthe water conservation analyst model the im-pact that planned BMP-implementation tim-ing may have on both demand projectionsand the timing of new capacity.

Although not explicitly discussed, thecalculator can also be used to evaluate theability of conservation to reduce the size ofthe next increment of supply. As previouslymentioned, the calculator was developed fordemonstration purposes; further developingthe calculator into a holistic net-benefit cal-culator is recommended. This would includeproviding calculations of yearly avoidableO&M costs of current and future supplies asa function of yearly cumulative water savings.It is also recommended to use linear pro-gramming to automatically generate an opti-mized implementation schedule thatmaximizes the net benefit using budget con-straints. SS


FWPCOA TRAINING CALENDARSCHEDULE YOUR CLASS TODAY!

* Backflow recertification is also available the last day of BackflowTester or Backflow Repair Classes with the exception of Deltona

** Evening classes

*** any retest given also

April4-6..........Backflow Repair* ..........................................St. Petersburg ....$275/305

11-15..........Reclaimed Water Field Site Inspector ........Osteen..............$350/38018-21..........*Backflow Tester............................................Bonita Springs ..$375/40518-21 ........Reclaimed Water Field Site Inspector ........St. Petersburg ....$350/380

29..........***Backflow Tester recert ............................Osteen..............$85/115

May2-5..........Backflow Tester ............................................Osteen..............$375/405

16-19..........*Backflow Tester............................................St. Petersburg ....$375/40516-20..........Utility Maintenance Level III ........................Osteen..............$225/255

27..........***Backflow Tester recert ............................Osteen..............$85/115

June6-10..........Wastewater Collection C, B ........................Osteen..............$225/255

20-22..........Backflow Repair ............................................Osteen..............$275/30527-30..........Backflow Tester*............................................St. Petersburg ....$375/405

24..........Backflow Tester recert*** ............................Osteen ............$85/11527- July 1 ......Water Distribution level 1............................Osteen..............$225/25527- July 1 ......Wastewater Collection A ............................Osteen..............$225/25527- July 1 ......Stormwater A ................................................Osteen..............$225/255

July11-15..........Reclaimed Water Field Site Inspector ........Deltona ............$350/38018-20..........Backflow Repair* ..........................................St. Petersburg ....$275/30525-28..........Backflow Tester ............................................Osteen..............$375/405

29..........Backflow Tester recert*** ............................Osteen..............$85/115

You are required to have your own calculator at state short schools

and most other courses.

Course registration forms are available at http://www.fwpcoa.org/forms.asp. For additional information on these courses or other training programs offered by the FWPCOA, please

contact the FW&PCOA Training Office at (321) 383-9690 or [email protected].



Contaminants Committee (formerly known as the Biological Contaminants Committee)

Affiliation: Florida Section AWWA

Current chair: Michelle Viale-Bick,microbiologist, TampaBay Water

Year group was formed: Nov. 29, 2005. The Contaminants Committeeis part of the Water Quality and ResourcesDivision, which is under the Technical andEducation Council.

Scope of work:The mission of the Contaminants Committeeis to promote forums and activities related tothe water contaminant component of waterquality, whether biological or chemical, andfacilitate the transfer of information andknowledge to the local water industry. Thecommittee aims to enhance communicationof knowledge and ideas amongmicrobiologists, chemists, epidemiologists,engineers, and other water professionals toimprove water quality.

Recent accomplishments:The Water Bugs is a lunchtime learningwebinar. The topic in January was RelativeAbundance and Diversity of AntibioticResistance Genes and Pathogens in ReclaimedVersus Potable Water Distribution Systems"and was presented by Emily Garner, a Ph.D.student at Virginia Tech.

We hosted a workshop at the FSAWWAconference last fall, Innovative Monitoringand treatment technology for ImprovingWater Quality, and at the 2015 Florida WaterResources Conference, PathogenRemoval/Inactivation and Risk Assessment in

Water and Wastewater Treatment Processes. The February Water Bugs webinar topicsincluded: S The Algenol Advantage (which covered

the use of algae to produce biofuels)S Life in a Biofilm: Amazing Yet IllusiveS Environmental and Public Health

Implications of Water Reuse: Antibiotics,Antibiotic Resistant Bacteria, andAntibiotic Resistant Genes

S The Centers for Disease Control Waterand Health Study: Do Water Main Breaksand Repair Events Pose a Health Risk?

Current projects:The latest lunchtime learning webinar,presented in March, had the following topicand presenter: S Abundance of Ammonia Oxidizing

Archaea in Water Treatment Plants andDistribution Systems with DifferentDisinfection Processes, Dhritikshama Roy,North Dakota State University.

Future work: We are planning a future webinar on leadcontamination in water and an overview onthe Flint, Mich., water crisis in the comingmonths, and were always developing othertopics and speakers for future webinars andworkshops that would be informative to waterand utility professionals.

We are also working on adding a committeewebpage to the FSAWWA website in the nearfuture, so people interested in our work can stayinformed. In the meantime, anyone interestedin joining the committee or being added to thewebinar mailing list can contact me by email [email protected] or by phoneat 813-613-4471.

Group members: The committee has 27 active members. S Vice-chair: Bina Nayak, Ph.D., water research

project manager, Pinellas County UtilitiesS Secretary: Melanie Lasch, special projects

manager, Veolia Water North AmericaS Pamela London-Exner, lab manager, Veolia

Water North AmericaS Amy Gilliam, Sr. Staff Scientist, Orange

County Utilities (past chair) S Andrew Randall, University of Central

FloridaS Anthony Andrade, Southwest Florida Water

Management DistrictS Bob Vincent, Florida Department of HealthS Candy Mulhern, Pasco CountyS Chance Lauderdale, Carollo EngineersS Daniel Meeroff, Florida Atlantic UniversityS Dean Bodager, Florida Department of HealthS Donna Mooren, Pinellas CountyS George LukasikS Jennifer Hunter, Pinellas CountyS John Gordy, City of Tampa S Jose Lopez, South Florida Water

Management DistrictS Kelli Levy, Pinellas CountyS Marsha Pryor, Pinellas County (retired)S Max Teplitski, University of Florida S Meifang Zhou, South Florida Water

Management District S Nwadiuto Esiobu, Florida Atlantic University S Paula Lowe, City of TampaS Robert Barque, Orange CountyS Tammy Spain, Draper Laboratory and

National Preparedness and Response ScienceBoard Member at U.S. Dept. of Health andHuman Services

S Thomas Gillogly, Carollo EngineersS Troy ScottS Valerie J. Harwood, University of South

Florida SS

FWRJ COMMITTEE PROFILE

This column highlights a committee, division, council, or other volunteer group of FSAWWA, FWEA, and FWPCOA.

FloridaSection


Everett L. Gill and T. Houston Flippin

Operators of refinery wastewater treatment facilities routinely measuresludge volume index (SVI), allowing them to detect deterioratingsludge settling quality. This test, however, does not allow the opera-

tor to accurately analyze secondary clarifier performance, including clarifiercapacity and the required return activated sludge (RAS) flow. A settling fluxanalysis is required to predict clarifier operation, yet the constants required togenerate the settling flux curve are difficult to develop.

For state-point analyses, settling flux curves must be representative ofthe biomass in the system or use a previously developed relationship betweenSVI and empirical sludge settling parameters, such as those developed byDaigger and Roper (1985), Daigger (1995), and Wahlberg and Keinath(1988/1995). These relationships were developed using municipal facilitieswith varied industrial contributions. Due to the inherent differences in thebiomass at both facilities, revised parameters were created for use in the pre-viously developed correlations between SVI and settling parameters for re-finery biomass.

Methodolgy

Zone settling velocities (ZSV) were obtained from settling columntests and used to generate empirical sludge settling constants Vo and K(Vesilind, 1974) at four separate refineries. The facilities that contain twosets of data were analyzed during periods with different biomass settlingcharacteristics (SVI values). The columns were large (4 to

Documents

Florida Water Resources Journal - April 2016