Your Water Wells: Think Life-Cycle Cost. Stuart Smith, CGWP Water Workshop All rights reserved

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Harvey Ward
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afford to neglect wells Well condition and performance inevitably deteriorate but decline can

2 Quickly reviewing: Investing in best design, materials, and performance optimization in new wells is an investment in reducing life-cycle cost of a long-term asset You may not be able to afford to neglect wells Well condition and performance inevitably deteriorate but decline can be slowed Adopting a "metrics-based" asset management strategy keeps wells performing at their best

3 Well and wellfield cost components Land Construction and equipment Exploration, design, testing Operations and maintenance including rehabilitation Power and consumables

4 Well and wellfield cost components Initial costs: Capital costs of well construction, pump, etc. Land acquisition and development Design, testing, permits, approval Future costs Energy, labor, water treatment Well rehabilitation Pump service and replacement Well replacement Land for new wells

5 Return on Investment (ROI) Building infrastructure is an investment ROI = Income (or an intangible or avoided trouble) obtained as a result Cost initial or lifecycle (LCC) LCC costs over lifespan of asset

6 Specific capacity Delay decay = more net revenue Optimal economical Q/s Reduced per-year costs (reduced unit cost of water production): Deferred need to buy 10 acres; design, approve, construct, hook in new well; extended optimal Q/s per kwh (lower cost of production) Minimum economical Q/s YYYYYYYYYYYYYY YYYYYYYYYYYYYY YYYYY

generate income) Complex Poor design and build =

7 Machine Analogies Combine or Municipal Well: Like these cost $ 6 figures Both investments (tools to generate income) Complex Poor design and build = expensive nuisance Maintenance assures long life and good ROI

8 Machine analogies: Initial quality Both car and girl seemed like good idea at the time

9 From dust you come and to dust you shall return Combine graveyard in Illinois Just like any other system operating in the environment: Wells deteriorate over time

10 They re quiet, but much is happening Wells clog and corrode: Clogging reduces capacity to transmit water Corrosion can mean waste downhole Don t forget water quality changes down there:

11 Operated for a long time untended: Clogging, impacts on water quality

12 Corrosion pump damage

13 Theoretical Drawdown Observed Drawdown Static WL Aquifer Pumping WL Well Pumping WL Clogs mean excessive drawdown: this causes excess power costs, etc. System Optimization = reduce actual drawdown

14 LCC study of well service Large Arizona wells: 1200 ft, 18 in diameter 1200 gpm 70 wells evaluated Recent O&M costs from City of Phoenix

15 Projected specific capacity trends

16 Arizona life-cycle costs

or sand-and-gravel) Drawdown 40-80 ft SWL =

17 An Ohio-typical LCC analysis Basis: 500 gpm wells in three-well wellfield (could be rock or sand-and-gravel) Drawdown ft SWL = 45 ft Eo = 50 % Power = $0.04 to $0.09/kwh 30 years

30-year lifecycle Modeled Buick initial construction: all topnotch

18 An Ohio-typical LCC analysis Basis: 500 gpm wells in three-well wellfield (could be rock or sand-and-gravel) Drawdown ft SWL = 45 ft Eo = 50 % Power = $0.04 to $0.09/kwh 30 years Scenarios: Varied specific capacity to model a 30-year lifecycle Modeled Buick initial construction: all topnotch components with infrequent cleaning and pump change Modeled Yugo low-cost initial construction, more frequent service

19 Specific capacity change only Difference per well between maintaining near original specific capacity and Average specific capacity: at $0.04/kwh = $25,000, at $0.09/kwh = $56,300 Worst specific capacity: at $0.04/kwh = $56,600, at $0.09/kwh = $144,380 Not a huge difference over lifespan is it?

Life-Cycle Cost: Buick vs. Yugo Buick wells = $250,000 each (all equipped) and Yugo wells = $105,000 Buick annualized cost $55,900 @ $0.04/kwh Yugo annualized cost $60,210@ $0.

20 Life-Cycle Cost: Buick vs. Yugo Buick wells = $250,000 each (all equipped) and Yugo wells = $105,000 Buick annualized cost $0.04/kwh Yugo annualized cost $60,210@ $0.04/kwh Expensive power spreads the difference LCC of Buick well: $1.99 million to $4.47 million LCC of Yugo well $2.1 million to $4.76 million Pays for doing the high-class job in the first place, at the very least

21 What s in a Buick well? Well site optimized re hydrogeology Materials selected to meet and exceed water quality and treatment issues Best possible pumps in this case, stainless steel submersibles Full-scale hydrogeologic testing Maintenance plan supplied

22 Materials Smooth and bestsuited to be corrosion-resistant Don t be afraid of newer options Ohio: Stainless steel pumps and as much plastic as feasible

23 Can you even afford to move over and drill new? Example: wellfield with 3 wells all gpm Not meeting current OEPA spacing requirements ½ mile+ to open space Can this be replaced?

24 Finding places that fit the regulatory requirements Then: endless horizon

Well testing: takes no longer to do it right than not Let the hydrogeologists (the qualified ones) design and perform the testing the good ones take their own data Document original aquifer and

25 Well testing: takes no longer to do it right than not Let the hydrogeologists (the qualified ones) design and perform the testing the good ones take their own data Document original aquifer and well hydraulic properties Base pump selection on stepdrawdown tests, not guessing Repeat step tests at well cleaning events (before and after) and periodically even if no well cleaning is needed

26 Best to keep what you have in You re kidding me right, hon? I need 300 ft isolation radius for a new well? We re cleaning the wells no matter what it good shape No, seriously, you do! It doesn t matter if your wells are 1200 ft deep. I can t tell you why that is. Apologies to Argentina Pres. Fernández de Kirchner and Secy of State Clinton costs

27 Asset management: A process definitions: "a process for maintaining a desired level of customer service at the best appropriate cost." (US EPA) a planning process to reduce cost, and increase efficiency and reliability while achieving service performance and business goals. (more generalized)

28 Out of sight, out of mind. Well faults are frequently hidden TD = 193 m (> 600 ft) below what s visible Problems hidden: Pumps clay in the rainy season Excessive nitrates

29 Out of sight, out of mind. TD = 134 ft below what s visible 25 ft of screen, 15-inch diameter Long history Lots going on down there

30 Well efficiency wisdom Big drops in specific capacity = drop in well efficiency (Ew theoretical : observed pumping drawdown) Drop in SC and Ew = higher system head = pump works harder More kwh per unit water pumped = degraded wire : water ratio = Costs more to pump water

31 The stakes: Energy Use of Pumps According to studies by the US Department of Energy: Over 50% of pump life cycle costs result from energy and maintenance expense Energy savings of 20% or more are possible with systems optimization

32 Q/s Performance history: Well 1 specific capacity history Original 1100 gpm Begin well cleaning period gpm Specific capacity = Flow rate/unit drawdown Years Attempt big fix

Trend Analysis: gal per kwh $80 per MG @ $0.

33 Trend Analysis: gal per kwh $80 per $0.09 per kwh Different well, data, and scale: same message costs more to pump water 700 gal/kwh $241 per $0.09 per kwh

34 Count the cost: Can you afford to skip the PM? Can you afford to do without that well during high-demand season? New pump every 5 years? Backwash filters twice as often? Random coliform positives? You can afford to site and develop new wells? Land, engineering, hydrogeology, construction

Attitude adjustment: Friends don t let friends Run to failure (neglect): go and sin no more Jesus (2 nd from L) with woman caught in the act of adultery and

35 Attitude adjustment: Friends don t let friends Run to failure (neglect): go and sin no more Jesus (2 nd from L) with woman caught in the act of adultery and her self-righteous accusers (quote aimed at all present ) story from Bible If your system has a history of run to failure Repent! Start a life of maintenance.

36 Weaknesses of A.M./O&M/ RCM processes etc. for wells Largely hidden Complex environment Uncontrolled conditions Signs of deterioration are subtle Deterioration long before symptoms start

37 The metric system : Key to well A.M./maintenance Data+trends equal forecasting Diagnostic information from tests tells you how the well is performing Water quality testing (physico- chemical, microbial) detects deteriorating effects Have data records? Plot trends Long data history? Better trends Know what was done in the past to inform the present and future.

38 Methods of well rehabilitation: Numerous Many new since 1990 Much improvement in chemistry and force application Learn the new ways Update your specs

39 The step test: A quick, valuable test The step test: Do it right (seldom done) Before AND after rehab Analyze not just pump guys filling out a form Gives you a pump curve + well/aquifer loss.

40 Charting specific capacity to analyze

41 1/Q/s T-M well 6 step testing 2003 Comparison well charts gpm 6/6/03 post-cleaning pre-cleaning Apr 1983 original

42 Now what do we do? After rehabilitation do not stop and put the file away! If you don t have one, start an asset management plan that includes the wells Make it practical, effective, and updatable Make it institutional: Not Martha s Pet Project

43 The Need for Records and Databases 1. Wellfield actions happen at long intervals 2. No one lasts forever help the next person 3. Spot trends and plan for actions before the crisis happens 4. Help your advisors help you

44 Then, use the information! You do not have to guess and work in the dark Knowing your costs, hydrologic factors such as specific capacity, water quality, power usage Keeping good records to do this Know your benefits as well as costs

45 Small system? Can t afford this Star Trek stuff? 1. You can t afford the alternatives 2. We mostly work with small systems 3. You can do it: It need not be complicated

46 Better documented and maintained systems have fewer regulatory issues District s systems so wellmaintained, have nothing to do zzzzzzz

items National Ground Water Association Our 2009 book Sustainable Wells (CRC Press

47 For further information: USEPA CUPPS web site (asset management planning for small systems) Search: Check Up Program for Small Systems (CUPSS) Some AWWA Bookstore items National Ground Water Association Our 2009 book Sustainable Wells (CRC Press or We have a day-long course on all this we can bring to you

48 Acknowledgment Marvin Glotfelty, RG Principal Hydrogeologist Clear Creek Associates Tucson, AZ

49 Questions? I ve got some time Did I mention the book?

50 Thanks for your attention Contacts: ,

Sustainable Wells: Role of Well Rehabilitation and Maintenance in Conservation

Sustainable Wells: Role of Well Rehabilitation and Maintenance in Conservation Stuart Smith, CGWP Water/Energy Sustainability Symposium Pittsburgh, PA September 26-29, 2010 2010 All rights reserved Energy