Sustainable Wells: Role of Well Rehabilitation and ... - Ohiowater.org

Sustainable Wells:Advances in Asset Managementfor Water WellsStuart Smith, CGWPAllen Comeskey, CPGOhio Section AWWAColumbus, Ohio, September 23, 2010© 2010 All rights reserved

Quickly addressing:• Developing and implementing a wellmaintenanceplan based on diagnostics,and why you should do it• The purpose and value of pre- and postcleaningperformance testing• How to anticipate and avoid wellperformance and water quality problems• Potential economic benefits• How regulatory agencies can promote anAM ethic in groundwater-source supplies.

“From dust you come and todust you shall return…”Some kid’sAcura inMichiganJust like any othersystem operating in theenvironment: Wellsdeteriorate over time

Out of sight, out ofmind….Well faults arefrequently hidden• TD = 193 m (> 600 ft)below what‟s visible• Problems hidden:• Pumps clay in therainy season• Excessive nitrates

Yet much is happening down there:• Wells clog andcorrode:• Clogging reducescapacity totransmit water• Corrosion canmean wastedownhole• Don‟t forget waterquality changes

Operated for a longtime untended:Clogging, impactson water quality

Pump cannot pump water well

Corrosion pump damage

Q/s14710131619222528313437Performance history:Well 1 specific capacity history4035302520151050Original SC @ 1100 gpmBegin wellcleaning periodSC @ 400-800 gpmSpecific capacity =Flow rate/unit drawdownYearsAttemptbig fix

Well efficiency and totalsystem optimization• Big drops in specific capacity (SC inprevious chart) = drop in wellefficiency (Ew – theoretical :observed pumping drawdown)• Drop in SC and Ew = higher systemhead = pump works harder• More kWh per unit water pumped =degraded wire : water ratio

Trend Analysis: gal per kWh$80 per MG @$0.09 per kWhDifferent well, data,and scale: samemessage – costsmore to pump water700 gal/kwh$241 per MG @$0.09 per kWh

The stakes: Energy Use of PumpsAccording to studies by the USDepartment of Energy:• Nearly 25% of electricity demandcomes from industrial motor systems• Over 50% of pump life cycle costsresult from energy and maintenanceexpense• Energy savings of 20% or more arepossible with systems optimizationwww.pumpsmatter.org

Finding places that fit theregulatory requirements … Then: endless horizonNow: strugglingto find acreageFilm Board of Canada

Best to keep what you have inYou’re kiddingme right, hon?I need 300 ftisolation radiusfor a new well?We‟recleaningthe wellsno matterwhat itcostsgood shapeNo, seriously,you do! Itdoesn’t matter ifyour wells are1200 ft deep. Ican’t tell youwhy that is.

Asset management: A processdefinitions:• "a process for maintaining a desired levelof customer service at the bestappropriate cost." (US EPA)• “a planning process to reduce cost, andincrease efficiency and reliability whileachieving service performance andbusiness goals.” (more generalized)

Asset Management: A Process Move from reactive to proactivemaintenance Know the costs and benefits ofrehabilitation vs replacement Look at lifecycle costs for critical assets Deploy resources based on asset conditions Develop and validate capital improvementplanList: US EPA

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

Attitude adjustment:Friends don‟t let friendsRun to failure (neglect):“go and sin no more…”Jesus (2 nd from L) with womancaught in the act of adultery and herself-righteous accusers (quote aimedat all present…) story from BibleIf your systemhas a history of„run to failure‟ –Repent! Start alife ofmaintenance.

Weaknesses of A.M./O&M/RCM processes etc. for wells …• Largely hidden• Complex environment• Uncontrolled conditions• Signs of deteriorationare subtle• Deterioration longbefore symptoms start

Keys to well A.M./maintenance:It‟s like weather forecasting,based on data and trends• Diagnostic information from tests tellsyou how the well is performing• Water quality testing (physicochemical,microbial) detectsdeteriorating effects• Have data records? Plot trends• Long data history? Better trends• Know what was done in the past toinform the present and future.

Methods of well rehabilitation:• Numerous• Many new since 1990• Much improvementin chemistry andforce application• Learn the new ways• Update your specs

Materials• Smooth and bestsuitedto becorrosion-resistant• Don‟t be afraid ofnewer options• Test!

Pre-cleaning well testing• Document precleaningcondition• Calculate well andaquifer loss• Compare pumpinghead to pump curve

Post-cleaning testing• Repeat tests at sameflow rates and samemethods• Calculate same values• Document changesafterwards• Repeat periodically evenif no well cleaning isneeded

The step test: A quick, valuable test• The step test:– Ideally 5 flow-rate (Q)steps well chosen– Well is stressed– Measure pressure at Q– Steps run to stability• Before AND after rehab• Analyze – not just pumpguys filling out a form• Gives you a pump curve+ well/aquifer loss.

Charting specificcapacity to analyze

1/Q/s0.090.080.070.06T-M well 6 step testing 2003Comparison well charts0.10.050.040.030.020.0100 100 200 300 400 500 600gpm6/6/03 post-cleaning pre-cleaning Apr 1983 original

Now what do we do?• After rehabilitation – do not stop andput the file away!• If you don‟t have one, start an assetmanagement plan that includes thewells• Make it practical, effective, andupdatable• Make it institutional: Not “Martha‟sPet Project”

The Need for Recordsand Databases1. Wellfield actions happen at longintervals2. No one lasts forever – help thenext person3. Spot trends and plan for actionsbefore the crisis happens4. Help your advisors help you

Then, use the information!• You do not have to guess and work inthe dark• Knowing your costs, hydrologic factorssuch as specific capacity, waterquality, power usage• Keeping good records to do this• Know your benefits as well as costs

Small system? Can‟t affordthis Star Trek stuff?1. You can‟t afford the alternatives2. We mostly work with small systems3. You can do it: It need not be complicated

Better documentedand maintainedsystems have fewerregulatory issuesDistrict‟s systemsso wellmaintained,havenothing to do…zzzzzzz

Regulatory roles:• U.S. EPA very activein encouraging A.M.• CUPSS initiative• Ohio EPA likewiseencouraging A.M.and P.M.• More on wells… butthey listen to us

For further information:• GAO report: Water Infrastructure –Comprehensive Asset Management has Potentialto Help Utilities Better identify Needs and PlanFuture Investments• USEPA CUPPS web site (asset managementplanning for small systems) Search: “Check UpProgram for Small Systems (CUPSS)”• Variety of AWWA Bookstore items• National Ground Water Association• Our 2009 book Sustainable Wells… (CRC Press)• We have a course on well M&R (AM, PM …)

Questions?I‟ve gotsometime…Nowpublished!CRC Press

Thanks for your attentionwww.groundwaterscience.comContacts: 419.358.0528stuart@groundwaterscience.com